Hymotion-Prius Plug-in Hybrid Electric Vehicle (PHEV)

Transcription

1 Hymotion-Prius Plug-in Hybrid Electric Vehicle (PHEV) Test Results Report September 2010 ecotechnology for Vehicles 1

2 Disclaimer notice Transport Canada's ecotechnology for Vehicles program ("etv") tests emerging vehicle technologies to assess their performance in accordance with established Canadian motor vehicle standards. The test results presented herein do not, in themselves, represent an official determination by Transport Canada regarding fuel consumption or compliance with safety and emission standards of any motor vehicle or motor vehicle component. Transport Canada does not certify, approve or endorse any motor vehicle product. Technologies selected for evaluation, and test results, are not intended to convey policy or recommendations on behalf of Transport Canada or the Government of Canada. Transport Canada and more generally the Government of Canada make no representation or warranty of any kind, either express or implied, as to the technologies selected for testing and evaluation by etv, nor as to their fitness for any particular use. Transport Canada and more generally the Government of Canada do not assume nor accept any liability arising from any use of the information and applications contained or provided on or through these test results. Transport Canada and more generally the Government of Canada do not assume nor accept any liability arising from any use of third party sourced content. Any comments concerning its content should be directed to: Transport Canada Environmental Initiatives (AHEC) ecotechnology for Vehicles (etv) Program 330 Sparks Street Place de Ville, Tower C Ottawa, Ontario K1A 0N5 [email protected] Her Majesty in Right of Canada, as represented by the Minister of Transport, ecotechnology for Vehicles 2

3 Table of Contents EXECUTIVE SUMMARY INTRODUCTION TESTING PROGRAM TESTING LOCATIONS VEHICLE OVERVIEW PHASE I LABORATORY FUEL CONSUMPTION AND EMISSIONS TESTING METHODOLOGY UTILITY FACTOR WEIGHTED FUEL AND ELECTRICAL CONSUMPTION Cycle Fuel Consumption Results Fuel Consumption Results Over Various Driving Cycles Dense City Driving Cycle (NYCC) Emissions Results PHASE II DYNAMIC TESTING ACCELERATION EVALUATION MAXIMUM SPEED HANDLING Lateral Skid Pad Emergency Lane Change Manoeuvre NOISE EMISSIONS TESTS BRAKING SUMMARY OF DYNAMIC TESTING RESULTS PHASE III - ON-ROAD EVALUATIONS CONCLUSION WHAT DOES THIS MEAN FOR CANADIANS? ecotechnology for Vehicles 3

4 EXECUTIVE SUMMARY Hybrid electric vehicles (HEVs) have the potential to reduce overall fuel consumption and emissions because they use an electric motor that operates as a complement to an internal combustion engine. As well, HEVs are often equipped with regenerative braking systems to recapture kinetic energy that would otherwise be lost as the vehicle slows, and use it to charge the batteries in conventional vehicles, this energy is lost as heat. A plug-in hybrid electric vehicle (PHEV) is a particular type of hybrid. It is equipped with batteries that can be recharged from an external power source, such as a standard 110 or 220-volt outlet. PHEVs can operate in a fully electric mode over a certain distance before the gas engine engages to provide power and/or charge the battery pack. PHEVs capable of operating in extended fully electric mode are of particular interest because they have the potential to significantly reduce the environmental impact of passenger vehicles in Canada. To date, no systematic laboratory emissions and dynamic performance testing has been conducted on PHEVs in Canada, perhaps because few PHEVs (either in production or prototypes) have been available for evaluation. In order to provide information to help address barriers facing PHEVs, the etv program, in partnership with Environment Canada, installed the A123 Systems Hymotion L5 Plug-In Conversion Module into a 2008 Toyota Prius. The module converts the vehicle from an ordinary hybrid into a PHEV, adding a high capacity lithium-ion battery pack that can be fully charged from any ordinary 110-volt electrical wall outlet over approximately five hours. Once the additional battery pack is depleted, the vehicle behaves essentially in the same manner as an unmodified hybrid vehicle. Generally, the Hymotion L5 Plug-in Conversion Module provides electric assistance over a range of kilometres. The Hymotion-Prius was tested and evaluated over three phases: laboratory fuel consumption and exhaust emissions testing; dynamic track testing; and on-road evaluations. The following is a summary of the results obtained from these evaluations. Criteria Results Fuel Consumption In charge-sustaining (normal hybrid) mode, the fuel consumption values are 4.0 L/100 km in the city, 4.2 L/100 km on the highway and 4.1 L/100 km combined city/highway. In charge-depleting (PHEV) mode, fuel consumption is 1.6 L/100 km in the city, 2.2 L/100 km on the highway and 1.9 L/100 km combined city/highway. Combined City/Highway Combined city and highway chargesustaining (normal hybrid) mode 4.1 L/100 km Combined city and highway chargedepleting (PHEV) mode 1.9 L/100 km Real-world driving in charge-depleting L/100 km (PHEV) mode The fuel consumption values for the Hymotion-Prius, in charge-depleting mode, are more than 75% below the 2009 model year Company Average Fuel Consumption (CAFC) value of 8.6 L/100 km and more than 70% below the overall fleet average (7.0 L/100 km) for all new 2009 vehicles. Even in charge-sustaining mode, the values for the Hymotion-Prius are more than 50% below CAFC value. ecotechnology for Vehicles 4

5 Criteria Results Based on 20,000 km of annual driving and a gasoline price of $1.00/L, depending on the combined use of charge-depleting and charge-sustaining modes, the fuel costs for the Hymotion-Prius should be between $500 and $700 per year. And with electricity at an average of 10 /kwh, depending on the combined use of charge-depleting and charge-sustaining mode, the annual electricity costs for the Hymotion-Prius could be $100 to $200 per year. Annually, the total cost of fuelling the Hymotion-Prius (gasoline and electricity combined) should be less than $800 per year. CO 2 Emissions In city and highway test cycles, the Hymotion-Prius produced a combined emissions value of 98 g CO 2 /km while in charge-sustaining (regular hybrid) mode and 44 g CO 2 /km while in charge-depleting (PHEV) mode, with a combined value for both modes of 84 g CO 2 /km. The Hymotion-Prius offers a 20% to 50% reduction in CO 2 emissions when compared to all of the best performers across all classes, for the same model year. Based on 20,000 km driven annually, the Hymotion-Prius leaves a low carbon footprint of 1,680 kg of CO 2 tailpipe emissions per year. Exhaust Emissions The Hymotion-Prius meets the emissions standards for Tier 2, Bin 5, and all emissions are well below the applicable regulated standards. Specifically, the Hymotion-Prius exceeds the fleet average Tier 2, Bin 5 standards prescribed by the U.S. Environmental Protection Agency and Environment Canada. Carbon Non-methane Nitrogen Formaldehyde Monoxide Hydrocarbons Oxide (HCHO) (CO) (NMHC) (NO x ) Hymotion-Prius Tier 2, Bin 5 (standard) Tier 2, Bin 2 (comparison only) Dynamic Performance Driver Evaluations Of note is that the Hymotion-Prius compares favourably to Tier 2, Bin 2, the cleanest bin that applies to vehicles that are not fully electric. The Hymotion-Prius is actually a conventional Toyota Prius with a small weight difference due to the additional battery pack placed in the spare tire compartment. This roughly 60 kg difference in weight, set low and to the rear of the vehicle did not adversely affect its dynamic performance. All aspects of handling and performance were good, pass or acceptable relative to the mid-size class. In addition, the vehicle met all aspects of CMVSS noise and braking standards. Drivers and occupants commented that the Hymotion-Prius conversion operated seamlessly. Those evaluators who took the car home overnight commented on the ease with which the vehicle could be plugged in to charge the conversion pack. Drivers and occupants of the vehicle commented that the Hymotion-Prius was quiet and offered a similar driving experience to other mid-size cars with regard to acceleration, handling and parking. Some evaluators cited issues with rearwindow visibility. As well, some mentioned that they felt distracted by the onboard display screen that monitors and reports on battery performance. ecotechnology for Vehicles 5

6 Barriers to the introduction of PHEV technology into the Canadian market PHEV technology is unique in that it incorporates both electric and internal combustion engine components. However, because of the electric element, PHEVs share many of the same types of barriers as battery electric vehicles. When it comes to PHEVs, consumer awareness, charging infrastructure and cost represent major barriers. Because a PHEV can operate in both fully electric and gasoline modes, range is not an issue. However, this technology will require a certain amount of consumer adaptation, particularly since the vehicle will need to be plugged into the electrical grid at home, at work or in other convenient locations. Yet, there are currently no standards relative to vehicle charging systems and to the interconnectivity of the grid. New vehicle codes and standards will be required to accommodate vehicle recharging from the grid, updating the Canadian Electrical Code, the Building Code and the Society of Automotive Engineers and other standards, as appropriate. As well, there exists little Canada-specific data and information about PHEV performance to inform power utilities, distributors and regulators as well as manufacturers. The kind of testing that etv has undertaken in relation to PHEV technologies is essential in helping to engage industry and stakeholders in the process of exploratory and proactive research leading to the development and modification of codes and standards. ecotechnology for Vehicles 6

7 1.0 INTRODUCTION Hybrid electric vehicles (HEVs) have the potential to reduce overall fuel consumption and emissions because they use an electric motor as a complement to an internal combustion engine. As well, HEVs are often equipped with regenerative braking systems to recapture kinetic energy that would otherwise be lost as the vehicle slows, and use it to charge the batteries in conventional vehicles, this energy is lost as heat. A plug-in hybrid electric vehicle (PHEV) is a particular kind of hybrid. It is equipped with batteries that can be recharged from an external power source, such as a standard 110 or 220-volt outlet. PHEVs can operate in a fully electric mode over a certain distance before the gas engine engages to provide power and/or charge the battery pack. PHEVs capable of operating in extended fully electric mode are of particular interest because they have the potential to significantly reduce the environmental impact of passenger vehicles in Canada. Hybrid vehicles have been commercialized for over ten years in North America. Many manufacturers are now planning to bring plug-in hybrid vehicles to market in the coming months. However, despite these imminent market plans, little systematic laboratory emissions and dynamic performance testing has been conducted on PHEVs in Canada, perhaps because few PHEVs (either production or prototype models) have been available for evaluation. In order to provide information to help address barriers facing PHEVs, the etv program, in partnership with Environment Canada, installed the A123 Systems Hymotion L5 Plug-In Conversion Module into a 2008 Toyota Prius. Hymotion, working out of Concord, Ontario, first introduced their conversion kits in The Massachusetts-based A123 Systems, which manufactures the batteries for the conversion module, acquired Hymotion in February Although originally designed to convert Toyota Prius and Ford Escape and Mercury Mariner Hybrids, the L5 Plug-in Conversion Modules (PCM) are now designed specifically to convert Toyota Prius HEVs into PHEVs, as an aftermarket conversion. The module is a high capacity lithium-ion battery that extends the vehicle s ability to operate solely on electric power. The lithium-ion battery supplies additional power in parallel with the factory installed nickel metal hydride (NiMH) battery pack. The L5 PCM, which extends the vehicle s operating range in all electric modes, is one example of PHEV technologies that may soon be available from major automotive manufacturers. The present report provides details and results on the evaluation of various aspects of the PHEV technologies found in the Hymotion-Prius. 2.0 TESTING PROGRAM The Hymotion-Prius was tested and evaluated over three distinct phases: laboratory fuel/energy consumption and exhaust emissions testing; dynamic track testing; and on-road evaluations. These various phases were intended to realistically assess the overall performance and battery efficiency, and identify any possible regulatory or consumer barriers that may negatively impact the introduction, in Canada, of the advanced technologies featured in the Hymotion-Prius. The Hymotion-Prius was evaluated using standard testing procedures for conventional vehicles, based on practices used by the Canadian Corporate Average Fuel Consumption (CAFC), the U.S. Environmental Protection Agency, the U.S. Department of Transportation, the International Standards Organization and the Society of Automotive Engineers. In some cases, modifications where required ecotechnology for Vehicles 7

8 to the standard testing procedures in order to accommodate the electric aspects of the vehicle (see Hymotion-Prius Test Plan for details). 3.0 TESTING LOCATIONS Phase I testing was performed in partnership with Environment Canada at the Emissions Measurement and Research Division located in Ottawa, Ontario. All fuel consumption and exhaust emissions testing was performed in a controlled laboratory, using a vehicle chassis dynamometer. The laboratory environment ensured that testing was completed to within ± 1 degree Celsius of the required test temperature. Additionally, the vehicle was tested over several separate driving cycles and was maintained to within a ± 1.5-km/h limit of the required speed. Phase II testing was performed at Transport Canada s test track facility in Blainville, Québec. The closed test track environment was necessary to ensure that testing was performed in a controlled setting and under controlled conditions. The test track is equipped with over 25 kilometres of road, including both a high-speed and low-speed circuit, to allow for a variety of tests. Phase III testing comprised on-road evaluations performed by Transport Canada staff as well as by automotive journalists at the program s public outreach events. 4.0 VEHICLE OVERVIEW Figure 1 L5 PCM and the Hymotion-Prius PHEV The L5 PCM converted the Toyota Prius from an ordinary hybrid electric vehicle into a plug-in hybrid electric vehicle (PHEV). The 2008 Toyota Prius, the base vehicle into which the L5 PCM was installed, is classified as a mid-size vehicle. It is equipped with a gasoline-electric hybrid power train that uses a 1.5-litre inline 4-cylinder gasoline engine and an AC electric motor linked in parallel through a continuously variable transmission. The conversion module adds a high capacity lithium-ion battery pack to the vehicle that can be charged from an ordinary 110-volt electrical wall outlet. The added battery does not charge from the engine or through regenerative braking this source of energy is collected and stored in the original Prius hybrid battery pack, as the vehicle was designed to do. The additional battery assists the original ecotechnology for Vehicles 8

9 hybrid battery in the delivery of electrical energy to power the vehicle. Therefore, the operation of the vehicle uses the same blended gas/electric mode of power delivery as the original vehicle. The increased electrical power from the added battery simply means that the vehicle can rely more on electricity and less on fossil fuel-based power. As a result, the vehicle can accelerate and attain greater speeds at higher loads while using only electrical power. There is also a benefit when the gasoline engine is operating, as a greater portion of the load is managed by the increased electrical power, thus reducing fuel consumption during this mode of operation as well. Once the additional battery pack is depleted, the vehicle reverts to simple hybrid mode. The specifications for the L5 PCM and the Hymotion-Prius are presented in Table 1. Hymotion L5 Battery Pack Specifications Fuel Efficiency and Performance Weight 85 kg Fuel / Energy Type Gasoline-Electric Length 840 mm Fuel Efficiency* 1.9 L/100km Width 420 mm Driving Range in km Blended Mode (Hymotion Battery) Height 260 mm All Electric Top Speed 55 km/h Type and Arrangement A123 Systems Lithium Ion Nanophosphate TM, 616 cells Charging Time 5.5 hours (110 V / 15 A) divided into 7 modules Voltage 190 V Operational Temperature Range -20 C to 45 C Capacity ~5 kwh CO 2 Emissions: Electric Only Regular Prius Available (Usable) Capacity Energy Density 0 g/km ~100 g/km ~4 kwh *Results based on a full battery state of charge, UDDS FTP-72 city driving cycle at 22 C 59 Wh/kg Table 1: Specifications for the Hymotion-Prius 5.0 PHASE I LABORATORY FUEL CONSUMPTION AND EMISSIONS TESTING More than 3,500 kilometres of vehicle and engine use were accumulated on the Hymotion-Prius, pursuant to the Code of Federal Regulations (CFR) mileage accumulation procedure, prior to the installation of the conversion module. Thus, it was only necessary to perform additional accumulation of a few hundred kilometres to ensure that the module was functioning properly in the vehicle. Once mileage accumulation was completed, the vehicle was soaked at a laboratory temperature for no less than eight hours before each test 1. This is to ensure that the vehicle may be compared against other test vehicles undergoing the same emissions and fuel consumption evaluations, and that all mechanical components and fluids reach the chosen temperature by the time of testing. Emissions and fuel consumption tests were performed as per the standard CFR procedures. All chassis dynamometer testing of federal standard cycles was conducted at the Emissions Research and Measurement Division (ERMD) of Environment Canada. Fuel consumption testing was performed according to the most recent SAE J1711 document available at time of testing (October 2009). 1 To soak a vehicle means to park it in the test chamber with the engine turned off, to allow the entire vehicle, including the engine, fluids, transmission and drive train, to reach the test cell temperature prior to beginning the test. ecotechnology for Vehicles 9

10 Evaluations were performed over the duty cycles listed in Table 2 below. Tests were conducted both in charge-sustaining or hybrid mode and charge-depleting or PHEV mode. Test Parameter Test Standard Urban Driving U.S. FTP-75 Cold Test U.S. FTP-72 Aggressive Driving US06 (SFTP) Highway Driving U.S. HWFET Electrical Load US SC03 Stop-and-go City Driving NYCC Table 2: Chassis Dynamometer Test Schedule The vehicle was mounted on a chassis dynamometer where the front wheels were allowed to roll against a resistance drum. The drum s resistance was pre-programmed based on the vehicle s road load force parameters. The result was a model for road load force as a function of speed, during operation on a dry, level road, under reference conditions of 20 C (68 F) and approximately 101 kpa (29.00 in-hg), with no wind or precipitation and with the transmission in neutral. Environment Canada collected and analyzed the following exhaust emissions: carbon monoxide carbon dioxide total hydrocarbons nitrogen oxides particulate matter Additionally, Environment Canada measured the rate of energy consumption and total energy supplied by the conversion module over tests using a Hioki 3193 Power HiTester measuring unit with Universal Clamp-On CT 9278 (200 A range). This was done in order to quantify the electricity (energy) use and determine the conversion module s state of charge and total capacity over the various duty cycles. 5.1 METHODOLOGY The fuel consumption estimate for the Hymotion-Prius is based on calculations for both the 2-cycle city and highway driving cycles and the 5-cycle city, highway, cold test, aggressive driving and electrical load driving cycles. The test cycles were developed based on extensive real-world data, such as driving activity, trip length and stopping frequency, among other factors. As test procedures for PHEVs were not officially established at time of testing, the results presented were obtained using the latest available procedures. A utility factor was applied to allow for the calculation of the combined fuel consumption performance during charge-sustaining and charge-depleting modes of operation. This utility factor was determined using the method described in SAE J Utility Factor Definitions for Plug-In Hybrid Electric Vehicles Using 2001 U.S. DOT National Household Travel Survey Data. The 2-cycle value was calculated by adding the results of the urban driving cycle (U.S. FTP-75) and the highway duty cycle (U.S. HWFET), using a ratio of 55% city to 45% highway. The cycles were then adjusted upward 10% and 15% respectively to account for a variety of real-world driving factors. The adjustments are meant to account for differences between the way vehicles are driven on the road ecotechnology for Vehicles 10

11 and over the test cycles in the laboratory. The end result is a combined fuel consumption rating for the vehicle, in addition to separate city and highway results. These are the procedures followed by Natural Resources Canada to determine the values that are published in their annual Canadian Fuel Consumption Guide. The U.S. 5-cycle test method is used to supplement the Canadian 2-cycle test method. It takes into account several important factors that affect fuel consumption but are not addressed in the current Canadian standard. In 2006, the U.S. Environmental Protection Agency began to implement 5-cycle testing, which includes testing over a wider range of driving patterns and temperature conditions than those tested under the current Canadian standard. For example, in the real world, vehicles are often driven more aggressively and at higher speeds than the existing city and highway test cycles attempt to duplicate. The US06 aggressive driving cycle takes this into account. Furthermore, drivers often use air conditioning in warm and/or humid conditions. In the 2-cycle calculation, this factor is not taken into consideration, since the test does not allow the air conditioning system to be turned on. The US SC03 test cycle reflects the added fuel needed to operate the air conditioning system. As well, given Canada s climate, a typical vehicle will be driven below 0 C (~ 32 F) on a fairly regular basis. The current 2-cycle testing is only conducted at 25 C (~ 77 F). The U.S. FTP-72 cold test cycle (-7 C) is used to reflect the additional fuel needed to start and operate an engine at lower temperatures. Using the 5-cycle method, therefore, offers a more accurate representation of the vehicle s fuel consumption and overall performance than the 2-cycle method. Both methods apply adjustment factors to take into account other real-world driving factors such as road grade, wind, low tire pressure and fuel quality. However, because it takes these factors into account, for the same make and model, the 5-cycle method results in fuel consumption values that are approximately 10 to 20% higher than those for the 2-cycle method. 5.2 UTILITY FACTOR WEIGHTED FUEL AND ELECTRICAL CONSUMPTION According to SAE J2841, utility factors may be used to combine charge-depleting and chargesustaining modes of a PHEV. This document defines utility factors for city (UDDS) and highway (HWFET) driving cycles, based on the 2001 U.S. Department of Transportation (DOT) National Household Travel Survey data. Utility factor weighted fuel consumption was calculated for the city and highway cycles using the following fractional utility factor method set out in SAE J2841. Where: UF = Utility Factor FCCD = Charge-Depleting Fuel Consumption FCCS = Charge-Sustaining Fuel Consumption (only hot-starts were included, although this is not specified in J2841) RCDC = Charge-Depleting Cycle Range Dcycle = Cycle Distance For this vehicle, the urban utility factor was , and the highway utility factor was Thus, for both city and highway driving cycles, the charge-depleting fuel consumption was weighted just slightly higher than the charge-sustaining fuel consumption. Fractional utility factors are shown in the table below. ecotechnology for Vehicles 11

12 Table 3: Utility Factors for City and Highway Cycles, as per SAE J Cycle Fuel Consumption Results The Hymotion-Prius was tested against the FTP-75 city cycle and the HWFET highway cycle, using the latest available Canadian standard for fuel consumption testing on PHEVs. The results were averaged for each cycle. In charge-sustaining mode, the Hymotion-Prius behaved as it normally would, that is like a regular hybrid vehicle. The fuel consumption in this mode of operation was determined to be the same as the published fuel consumption for a 2008 Toyota Prius 4.0 L/100 km city, 4.2 L/100 km highway and 4.1 L/100 km combined city/highway. The results for the fuel consumption of the Hymotion-Prius in charge-depleting mode, based on the 2-cycle calculations and using the correction factors listed in Table 3 are 1.6 L/100 km for the city, 2.2 L/100 km for the highway and 1.9 L/100 km combined city/highway. The range in charge-depleting mode indicates approximately the distance travelled before the PHEV battery energy is depleted. Once the charge-depleting range is exhausted, the Hymotion-Prius behaves like an ordinary hybrid vehicle, operating as it did before the retrofit conversion into a PHEV. The charge-depleting range determined during testing was 47.8 km (29.7 miles) while driving the city cycle and 49.5 km (30.8 miles) while driving the highway cycle. Fuel consumption values that combine the charge-sustaining and charge-depleting modes, using the utility factor set out in Table 3 above, are 3.3 L/100 km city and 3.5 L/100 km highway. The overall combined fuel consumption, using a 55% and 45% weighting for the city and highway respectively, is 3.4 L/100 km Fuel Consumption Results Over Various Driving Cycles Since there is currently no official procedure for determining the 5-cycle fuel consumption value for PHEVs, the following is provided for information purposes only. The fuel consumption results of the Hymotion-Prius over various cycles illustrate the effects of different driving conditions on the fuel consumption of the PHEV. The results for the fuel consumption of the Hymotion-Prius, based on 5-cycle testing, are ecotechnology for Vehicles 12

13 2.0 L/100 km city and 2.5 L/100 km highway. The 5-cycle testing values may provide a more accurate representation of what a user can expect for fuel/energy consumption in real-world driving. When compared against the city and highway values for the 2-cycle calculation, the 5-cycle fuel consumption values are 25% and 15% higher for city and highway driving respectively. Driving Cycle City Highway Combined 2-cycle cycle Table 4: Adjusted Fuel Consumption Results in Charge-Depleting Mode, by Driving Cycle Figure 2 below shows the unadjusted 2-cycle combined fuel consumption (with utility factor) value of 3.0 L/100 km versus the fleet average for model year 2009 and the Canadian CAFC/U.S. CAFE standards. It can be seen that the Hymotion-Prius is more than 65% below the 2009 model year CAFC standard of 8.6 L/100 km and more than 55% below the actual fleet average achieved by all new cars in 2009 of 7.0 L/100 km. Note: CAFC regulations use unadjusted fuel consumption values. Foot print and L/100 km, CAFE/CAFC - Cars 12,0 10,0 8,0 L/100 km 6,0 4,0 2,0 US Canada Fleet Average Target Hymotion-Prius 0,0 25,0 30,0 35,0 40,0 45,0 50,0 55,0 60,0 65,0 70,0 75,0 Footprint (square feet) Figure 2 Unadjusted Fuel Consumption versus Canadian and U.S. Standards Dense City Driving Cycle (NYCC) The configuration of the Hymotion-Prius allows it to achieve exceptionally low fuel consumption in city driving conditions. The New York City Cycle (NYCC) is a driving cycle that simulates stop-andgo inner city traffic conditions, with low speed driving and frequent stops. Conventional vehicles experience very significant increases in fuel consumption in stop-and-go city traffic. The cycle includes 14 stops and takes 598 seconds (nearly 10 minutes) to complete, with a total distance of 1.9 km (1.2 miles) travelled. The average speed of the cycle is 11.4 km/h (7.1 mph) and the maximum speed of the cycle is 44.6 km/h (27.7 mph). The testing for this cycle was performed with an ambient temperature between C (68-86 F). ecotechnology for Vehicles 13

14 The NYCC cycle was repeated several times in a row to measure the vehicle s consumption while operating in both charge-depleting mode and charge-sustaining mode. From the repeated cycles, it was also possible to determine when the energy from the L5 battery pack was depleting and the vehicle transitioned from charge-depleting to charge-sustaining mode. Cycle Number Fuel Consumption over cycle Cumulative distance travelled (L/100 km) (km) Table 5: Fuel Consumption Results during NYCC As can be seen in Table 5 above, the vehicle operated in charge-depleting mode during cycles 2 through 14. However, the vehicle transitioned from charge-depleting to charge-sustaining mode at approximately 0.3 km into the 15 th cycle, as indicated by the increase in the fuel consumption. This means that the vehicle is able to travel nearly 30 kilometres in charge-depleting or PHEV mode over the NYCC cycle. Other less-demanding cycles, as well as real-world driving, have shown that the L5 battery pack is capable of providing electrical assistance in the km range Emissions Results The results of the city and highway test cycles offer a combined CO 2 emissions value of 98 g CO 2 /km and 44 g CO 2 /km for hybrid and PHEV modes respectively. The value obtained with the utility factor is 84 g CO 2 /km, which is a little more than halfway in between the hybrid and PHEV values. It is no surprise that the best mid-size car for the same model year available on the Canadian market is the 2008 Toyota Prius. In fact, despite being in the mid-size class, the Toyota Prius was the lowest CO 2 emitting car of all vehicles across all classes. Thus the Hymotion-Prius offers approximately a 20%-50% reduction in CO 2 emissions over the best performers across all classes, in charge-depleting mode. ecotechnology for Vehicles 14

15 When compared to the national average of all cars available in Canada, the CO 2 emissions reported for the same model year are 188 g CO 2 /km. The Hymotion-Prius therefore offers a 55% improvement in CO 2 emissions over the average passenger car available in Canada. Hybrid or Charge-Sustaining PHEV or Charge-Depleting Combined Modes Mode Mode 98 g CO 2 /km 44 g CO 2 /km 84 g CO 2 /km Table 6: Adjusted CO 2 emissions in various modes (g/km) With regard to non-co 2 exhaust emissions, the Hymotion-Prius meets the Tier 2, Bin 5 emissions standards, and all emissions are well below the applicable regulated standards. Specifically, the Hymotion-Prius exceeds the fleet average Tier 2, Bin 5 standards prescribed by the U.S. Environmental Protection Agency and Environment Canada. Tier 2, Bin 2, the cleanest bin that applies to vehicles that are not fully electric, is provided in Table 7 below, for comparison purposes only. Carbon Monoxide (CO) Non-methane hydrocarbons (NMHC) Formaldehyde (HCHO) Nitrogen Oxide (NO x ) Hymotion-Prius Standard Tier 2, Bin Tier 2, Bin 2 (for comparison only) Table 7: Federal Test Procedure, Exhaust Emissions vs.standards (g/mile) Generally speaking, gasoline-powered vehicles have little difficulty in meeting particulate matter (PM) and nitrogen oxide (NO x ) emission standards. These remain an issue for diesel engines, which achieve combustion temperatures that are much higher than gasoline-powered vehicles. However, carbon monoxide and hydrocarbons pose a greater challenge to gasoline-powered vehicles. Any time a vehicle uses excess fuel, a portion of the fuel may burn incompletely, resulting in unburned hydrocarbons and carbon monoxide (oxidized carbon) being emitted from the tailpipe. As expected, the Hymotion-Prius easily meets the carbon monoxide and hydrocarbon emission standards in place in Canada and the United States the base vehicle is a conventional Prius, which must meet these same standards. However, the intermittent nature of the engagement of the internal combustion engine when operating as a PHEV did produce sometimes higher and sometimes lower emissions during the various duty cycles over which the vehicle was assessed. It should be noted that emissions as well as fuel consumption standards are met on a manufacturer s sales weighted average. Individual models may exceed these standards as long as the manufacturer s fleet as a whole is in compliance. However, Hymotion is not an original equipment manufacturer, but a company that converts existing conforming vehicles. As such, it does not need to conform to the same set of standards and regulations or make the same data submissions to the federal government. ecotechnology for Vehicles 15

16 6.0 PHASE II DYNAMIC TESTING The Hymotion-Prius underwent dynamic and performance testing in September and October Most aspects of the tests performed were not for compliance or regulatory purposes, as set out in the Canada Motor Vehicle Safety Standards (CMVSS), but for general dynamic assessment, to evaluate how well smaller, more fuel-efficient vehicles perform under a variety of road conditions and situations. Concerns about fuel-efficient vehicles are not always limited to exhaust emissions and greenhouse gas reductions. Additionally, the etv program wished to identify any possible issues that may arise with any of its test vehicles undergoing extensive dynamic testing, especially non-oem or converted vehicles such as the Hymotion-Prius. As mentioned previously, the dynamic testing was performed at Transport Canada s test facility in Blainville, Québec. An aerial view of the test track is provided below. Figure 3: Aerial View of Dynamic Test Track, Blainville (QC) 6.1 ACCELERATION EVALUATION The maximum acceleration was determined by starting the vehicle from a standing start and following the procedure set out below. 1. The vehicle was evaluated by accelerating to the maximum attainable speed in a quarter mile (402.3 m). 2. The vehicle was evaluated by accelerating to the maximum attainable speed in a kilometre (1,000 m). These tests were conducted on July 15, The wind speed on that day was 20 km/h, blowing from the northwest. To account for variations in wind, the vehicle was driven in both directions on the test track, with the results averaged. Distance Speed ( km/hr ) 0.25 mile ( m) ,000 m Table 8: Average Results for Specified Distances ecotechnology for Vehicles 16

17 Figure 4: Curve Showing Distance and Speed vs. Time During Acceleration 6.2 MAXIMUM SPEED The Hymotion-Prius is equipped with a type of continuously variable transmission (CVT). In a true CVT, there are an infinite number of gear ratios available for the transmission to access. This is advantageous because the more gear ratios there are, the more choices the vehicle has in setting the engine spin rate for any given speed. As a result, both power and cruising requirements are met by raising or lowering the engine spin rate and reducing losses associated with the fast moving internal engine parts. This is typically achieved through the use of a system of belts and pulleys adjusting the position of the belt between two pulleys. The Prius has a unique type of single-gear ratio CVT. In effect, it is a single-gear transmission that simply spins more quickly or more slowly to attain the desired speed. Effectively, the engine is coupled to the wheels as if the vehicle were always in top gear. This would normally not allow for enough low-end torque to be available at low speeds and is why conventional vehicles have a selection of gear ratios (think of trying to move forward from a full stop in 4 th gear). However, the presence of the powerful electric motor in addition to the gasoline engine allows the Prius to function well with a single-gear ratio CVT. The maximum speed attainable was tested and recorded for each test run. The vehicle was accelerated until a top speed was recorded. Since speed is affected by wind, tests were performed in both directions and averaged. The maximum speed attained was km/h. ecotechnology for Vehicles 17

18 6.3 HANDLING Lateral Skid Pad The lateral skid pad test was used to determine the maximum speed that the Hymotion-Prius could achieve in a cornering situation. When a vehicle reaches its cornering limit, it will either under-steer or oversteer, losing traction on the curve. The maximum lateral acceleration was recorded when the test vehicle had almost lost traction,. In order to measure vehicle displacement, speed and lateral acceleration, the Hymotion-Prius was equipped with a combined GPS and accelerometer-based data acquisition system. All measurements refer to the vehicle s centre of gravity. Tires were warmed up and conditioned by using a sinusoidal steering pattern at a frequency of 1 Hz, a peak steering-wheel angle amplitude corresponding to a peak lateral acceleration of g, and a speed of 56 km/h. The vehicle was driven through the course four times, as shown in Figure 5 below, performing 10 cycles of sinusoidal steering during each pass. Testing was performed under the following conditions: The vehicle was equipped with new tires; Tire pressure was adjusted to conform to the manufacturer s recommendations; The vehicle s weight was adjusted to its lightly loaded condition; The skid pad was 61 m in diameter. Figure 5: Test Vehicle During Clockwise Run The results presented in Table 9 below show that the maximum speed that the vehicle can achieve in a cornering situation in either direction is km/h. At higher speeds, the vehicle s electronic stability control (ESC) self-activates and does not allow the vehicle to exceed 55 km/h. ecotechnology for Vehicles 18

19 Clockwise Counter-Clockwise Speed (km/h) Stay Inside Corridor? (Yes/No) Speed (km/h) Stay Inside Corridor? (Yes/No) 55 Yes 55 Yes 58 Yes 57 Yes 61 No 61 No 58 Yes 59 Yes Table 9: Skid Pad Test Results The maximum lateral acceleration that was maintained without leaving the skid pad was 8.2 m/s 2. The results clearly show that, in a clockwise direction, the car reached its cornering limit at 58 km/h, and in a counter-clockwise direction, it reached its cornering limit at 57 km/h. In both directions, the vehicle lost traction (under-steering situation) at 61 km/h Emergency Lane Change Manoeuvre The emergency lane change manoeuvre with obstacle avoidance test was performed, based on ISO : 2002 Passenger Cars Test Track for a severe lane change manoeuvre. During this test, the vehicle entered the course at a particular speed and the throttle was released. The driver then attempted to negotiate the course without striking the pylons. The test speed was progressively increased until instability occurred or the course could not be negotiated. Figure 6: Emergency Lane Change Course As illustrated in Figure 6, Section 4 of the course was shorter than Section 2 by one metre in order to get maximum lateral acceleration at this area. Tests were performed in one direction only. If any pylons were hit, as seen in Figure 7 below, the run was disallowed. ecotechnology for Vehicles 19

20 Figure 7: Emergency Lane Change Course, Unsuccessful Run Several tests were necessary to determine at which speed the Hymotion-Prius was able to negotiate all the way through the prescribed course without hitting a pylon. Table 10 below lists all runs in increasing order, by speed. Initial Speed (km/h) Pylon Hit? (Yes/No) 52 No 55 No 57 No 61 No 65 No 70 Yes Table 10: Hymotion-Prius Emergency Lane Change Results While there is no pass or fail in terms of speed for emergency lane change manoeuvres, this is a fair assessment of the lateral stability of a vehicle during rapid cornering. The maximum successful entry speed through the course was recorded as 65 km/h. This result is fair compared to other vehicles that the etv program has tested. At 70 km/h, the vehicle failed to perform the manoeuvre without striking pylons. ecotechnology for Vehicles 20

21 Figure 8: Lateral Accelerations Recorded During Emergency Lane Change Manoeuvres As seen in Figure 8 above, the maximum lateral acceleration recorded on a successful emergency lane change was 9.3 m/s 2, which is higher than the result obtained over the skid pad test (8.2 m/s 2 ). 6.4 NOISE EMISSIONS TESTS Noise is not often a concern with gasoline-powered vehicles. The Hymotion-Prius was tested in accordance with the CMVSS 1106 Noise Emissions Test, SAE Recommended Practice J986, Sound Level for Passenger Cars and Light Trucks and SAE Standard J1470, Measurement of Noise Emitted by Accelerating Highway Vehicles. An acceptable performance for a light-duty vehicle is when the exterior sound level does not exceed 80 dba after a value of 2 dba has been subtracted from the highest average sound level recorded during the test. In order to measure noise emitted from the engine and exhaust, microphones were set up as shown in Figure 9 below. ecotechnology for Vehicles 21

22 Figure 9 : Noise Emissions Setup Testing was performed under the following conditions: The vehicle test weight, including driver and instrumentation, did not exceed the vehicle s curb weight by more than 125 kg; For a period of one minute, the vehicle s engine speed was returned to idle and the vehicle s transmission was set in neutral gear before each run, in order to stabilize the initial transmission and exhaust system temperatures; The test surface was clean, smooth, dry and level. The test procedure for the acceleration tests was as follows: When the vehicle approached a speed of 48 km/h ± 1.2 km/h, the speed was stabilized before the acceleration point; At the acceleration point (± 1.5 m), as rapidly as it was possible to establish, the throttle was opened wide; Acceleration continued until the entire vehicle had exited the test zone; The sound meter was set to fast db(a). The deceleration tests followed the same procedure as above, with one modification at the deceleration point, the vehicle was returned to its idle position until it was equal to one half of the approaching speed or until the entire vehicle had exited the test zone. Results from all tests show that the ambient noise levels are within the limits of the CMVSS 1106 standards. Due to the logarithmic nature of the decibel scale, a level of 62 db is significantly lower than the 80-decibel limit. Generally 60 db is considered to be the level of normal human conversation while 90 db would be the sound generated by a typical lawn mower. Most of the noise being generated from the vehicle at these speeds is due to tire and wind resistance, which is acceptable and similar across any vehicle power train platform. ecotechnology for Vehicles 22

23 Test Side # Approaching Speed (km/h) Approaching RPM End Speed (1) (km/h) RPM max (1) Noise Level db (A) Calibration db (A) Right (3) (Note) Right Right Right Average Left Left Left Left Legend: (1) Test Side # Average Results = Highest Average 2dB 62.1 Ambient Noise (2) 47.6 Throttle full open until the entire vehicle has vacated the test zone (2) Ambient noise level less than the measured vehicle noise level by at least 10 db(a) (3) With a running gasoline engine Table11: External Noise During Acceleration Results Results : Pass Note: Depending on the actual battery charging level during the test, the vehicle approached the entry either with or without the help of the gasoline engine. In order to solve this problem, we decreased the distance that is normally reserved for stabilizing the initial incoming speed. That way, the gasoline engine was always running. Approaching Speed (km/h) Approaching RPM End Speed (1) (km/h) RPM max (1) Noise Level db (A) Calibration db (A) Right N/A Right N/A Right N/A Right N/A Average Left N/A Left N/A Left N/A Left N/A Average Results = Highest Average 2dB 61.0 Ambient Noise (2) 46.8 Legend: (1) Throttle returned to its idle position until the entire vehicle has vacated the test zone (2) Ambient noise level less than the measured vehicle noise level by at least 10 db(a) Table 12: External Noise, Approaching 67 km/h Results : Pass Interior noise emitted from the vehicle was evaluated at different constant speeds, as well as during full acceleration, in order to determine the levels experienced by the driver of the vehicle. To measure the interior noise level, a microphone was placed within 6 inches of the driver s right ear. It is interesting to note that, except for idling, the Hymotion-Prius experienced a higher db within the vehicle than the values recorded externally. ecotechnology for Vehicles 23

24 Test # and Targeted Calibration Noise Level Transmission Selection Test Speed db (A) db (A) Idle Neutral Ambient Temperature 32.0 Engine Off Full Acceleration sec. 120 km/h Full Acceleration sec. 120 km/h Full acceleration sec. 120 km/h Average sec. 120 km/h 110 km/h Drive 110 km/h Drive 110 km/h Drive Average 73.4 Drive 100 km/h Drive 100 km/h Drive 100 km/h Drive Average 71.6 Drive 80 km/h Drive 80 km/h Drive 80 km/h Drive Average 69.4 Drive 50 km/h Drive 50 km/h Drive 50 km/h Drive Average 64.9 Drive Table 13: Internal Noise 6.5 BRAKING The original vehicle had to pass all required braking tests in order to satisfy the requirements set out in the CMVSS. It was therefore decided that testing according to the strict and resource-intensive procedures set out in CMVSS Light Vehicle Brake Systems was unnecessary. Therefore, a simplified brake testing procedure was performed to determine the stopping distance for abrupt stops from the following speeds: 50 km/h (30 mph) to 0 km/h / (mph) 6 stops, averaged 80 km/h (50 mph) to 0 km/h / (mph) 6 stops, averaged 100 km/h (60 mph) to 0 km/h / (mph) 6 stops, averaged 110 km/h (70 mph) to 0 km/h / (mph) 6 stops, averaged The vehicle total braking distance in metres and time in seconds was recorded. Since the test vehicle was equipped with ABS brakes, the test driver fully depressed the brake pedal, allowing the computer to modulate the callipers. If the wheels locked, the result was disregarded. The braking tests were conducted under the following conditions: Vehicle load: Lightly Loaded Vehicle Mass (LLVM) Transmission position: In neutral (N) Initial brake temperature: 100 C Pedal force: as necessary to activate ABS Wheel lockup: No lockup of any wheel for longer than 0.1 second allowed at speeds greater than 15 km/h Number of runs: 6 Test surface: Maximum coefficient of friction of 0.9 Stopping distance for reduced test speed: S 0.10V V 2 ecotechnology for Vehicles 24

25 Figure 10 below summarizes the braking results for the Hymotion-Prius. The threshold values are the limits that determine failure from given initial speeds. The best stopping distance recorded (out of the six trials) is indicated for each initial speed. Figure 10: Hymotion-Prius Braking Performance As the results demonstrate, the retrofit conversion to a PHEV has had a only a minor effect on the braking performance of the original vehicle, and does not nullify the vehicle s certification. The Hymotion-Prius remains fully compliant with all aspects of the CMVSS 135 standard. From the results, it is clear that there are no concerns about the vehicle s braking performance under normal driving conditions. It should be noted, however, that it is typical for all vehicles to exceed the highspeed braking standard by a greater relative amount than the low-speed braking standard. This is partially due to the difficulty in applying maximum braking pressure at the start of the brake test. 6.6 SUMMARY OF DYNAMIC TESTING RESULTS The Hymotion-Prius is actually a conventional Toyota Prius with a small weight difference due to the additional battery pack placed in the spare tire compartment. This roughly 60 kg difference in weight, set low and to the rear of the vehicle did not adversely affect its dynamic performance. All aspects of handling and performance were good, pass or acceptable relative to the mid-size class. Its dynamic performance was similar to that of market competitors in its class. In addition, the vehicle met all aspects of CMVSS noise and braking standards. 7.0 PHASE III - ON-ROAD EVALUATIONS The etv engineering team and other Transport Canada staff had the opportunity to evaluate the Hymotion-Prius on the streets of Ottawa. After test-driving the vehicle, drivers were asked to complete a two-page questionnaire to determine their general assessment of the vehicle and its performance as a PHEV. Drivers and occupants commented that the Hymotion-Prius conversion operated seamlessly. They generally seemed unaware of a difference or change between power supplied from the conversion battery pack and the conventional hybrid battery pack. Those evaluators who took the car home overnight commented on the ease with which the vehicle could be plugged in to charge the conversion pack. ecotechnology for Vehicles 25

26 Drivers and occupants of the vehicle commented that the Hymotion-Prius was quiet and provided a similar driving experience to other mid-size cars with regard to acceleration, handling, parking and general visibility. However, several users remarked on the placement of the rear spoiler a Prius design feature which somewhat impairs rear window visibility. As well, certain users mentioned the loss of cargo space if they were to drive with the spare tire, which must be stored in the general storage area because the conversion pack battery takes up the original space. In addition, some driver evaluators indicated that they felt distracted by the onboard display screen that monitors and reports on the performance of the conversion module and the electric battery. In addition, driver evaluators did not feel that the display was intuitive and easily understood. Over 1,000 km of evaluations were performed on this vehicle, with an average real-world fuel consumption of less than 4.0 L/100 km being reported. Evaluations were performed both with the PHEV engaged and while operating only as a conventional hybrid. When operated in PHEV mode, drivers generally obtained fuel consumption values of L/100 km, a result close to the PHEV values obtained by applying the utility factors. For Canadians, therefore, the Hymotion-Prius, and PHEV technology in general, offer significant annual fuel savings. 8.0 CONCLUSION To date, no systematic laboratory emissions and dynamic performance testing has been conducted on PHEVs in Canada, perhaps because few PHEVs (either in production or prototypes) have been available for evaluation. etv chose to install the A123 Systems Hymotion L5 Plug-in Conversion Module into a 2008 Toyota Prius because we wanted to gauge the viability of PHEV technologies under Canadian road and climate conditions and to identify any potential barriers to their introduction in the Canadian market. In charge-depleting or PHEV mode, in laboratory testing, the Hymotion-Prius obtained combined city/highway fuel consumption values of 1.9 L/100 km. While the values obtained during real-world driving evaluations are slightly higher at 2.5 to 3.5 L/100 km, they are still considerable lower than the 2009 model year CAFC value of 8.6 L/100 km reported for the comparable class of vehicle. In terms of CO 2 emissions, while in charge-depleting or PHEV mode, the Hymotion-Prius produced 44 g CO 2 /km, offering a reduction in CO 2 emission of up to 50% when compared to the best performers across all classes, for the same model year. In addition, the Hymotion-Prius meets the emission standards for Tier 2, Bin 5 and even compares favourably with Tier 2, Bin 2, the cleanest bin that applies to vehicles that are not fully electric. The Hymotion-Prius carries an additional 60 kg because of the battery pack placed in the spare tire compartment. This added weight, set low and to the rear of the vehicle, did not adversely affect its dynamic performance. In fact, its dynamic performance was similar to that of market competitors in its class. Drivers and occupants commented that the Hymotion-Prius operated seamlessly, was quiet and offered a similar experience to other mid-size cars with regard to acceleration, handling and parking. 9.0 WHAT DOES THIS MEAN FOR CANADIANS? Consumers still have questions with respect to how hybrids and PHEVs charge their batteries and how regenerative braking works, as well as concerns about battery lifespan, replacement cost and ecotechnology for Vehicles 26

27 safety performance. Many do not appreciate the environmental and financial benefits that fuelefficient technologies can offer. The etv program is helping to inform Canadians about PHEVs through its outreach events and through its website, which includes a wealth of information as well as videos. In terms of cost, at an estimated $1.00 per litre, approximately 200,000 kilometres would need to be driven before the fuel savings offset the cost of the conversion (~$9,000). However, once PHEVs are manufactured by OEMs in large production volumes, the cost differential relative to conventional gasoline and diesel vehicles will likely decrease significantly. As well, for owners of a PHEV to experience the full environmental benefits of technology, they would ideally have access to a 110 V charging at their place of work, or have a round trip commute of less than 60 kilometres. etv is one of the first government programs to obtain and conduct in-depth emissions, energy consumption, dynamic and on-road performance testing of PHEV technologies in Canada. Because PHEVs are plugged into the electrical grid, they are considered to be an electrical appliance and need to conform to a new set of standards that previously did not apply to vehicles. etv is working with industry and other government departments, using the test results from the A123 Conversion Module, to develop the codes and standards necessary to ensure PHEVs are on Canadian roads as soon as possible. ecotechnology for Vehicles 27