windera s PRODUCT MANUAL

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2 OPERATION MODE This is codified with code I.H4.V EDITION CHANGES WHO DATE 00 Initial edition JCA 30/08/ Changes in section 6.2 and 8 MP 10/09/2014 2

3 CONTENTS CONTENTS 1. ABOUT ENNERA ABOUT WINDERA S 4 2. ADVANTAGES OF IMPORTANT SAFETY INSTRUCTIONS DECLARATION OF CONFORMITY TO STANDARDS TURBINE-RELATED STANDARDS CONVERTER-RELATED STANDARDS 8 5. WARRANTY WHAT DOES IT INCLUDE? WHAT IS NOT INCLUDED? LIMITATIONS AND EXCLUSIONS CUSTOMER RESPONSIBILITIES SYSTEM DESCRIPTION SMALL WIND TURBINE COMPONENTS Front cone Rotor Technical specifications Hub Generator Technical specifications Centrifuge brake Vane Yaw System Tower Technical specifications Converter 25 3

4 CONTENTS Technical specifications Monitoring and communications Financial information Weather information Technical and environmental information OPERATION Emergency stop Controlled stop WINDERA S GENERAL SPECIFICATIONS COMPETITIVE ADVANTAGES AND INNOVATIONS COMPETITIVE ADVANTAGES INNOVATIONS INSPECTIONS AND MAINTENANCE VISUAL INSPECTIONS NOISE INSPECTIONS MAINTENANCE TROUBLESHOOTING FREQUENTLY ASKED QUESTIONS GENERAL QUESTIONS TECHNICAL QUESTIONS RECYCLING ANNEXES ELECTRICAL CONNECTION DIAGRAM GENERAL DIMENSIONS DRAWING 39 4

5 ABOUT ENNERA 1. ABOUT ENNERA Ennera is a renewable energy and sustainable mobility subsidiary of the CAF Group, a listed private company specialised in the design, manufacture, maintenance and supply of railway system equipment and components. Ennera's fundamental characteristic is its experience in offering renewable energy and sustained mobility solutions with the maximum investment guarantee from an ecological perspective: Ennera is a specialised business firm. It has accumulated wide-ranging experience in providing customised solutions. The company works with carefully selected and certified installers and suppliers. Ennera satisfies customer requirements for the development of state-of-the art technological solutions for small renewable energy systems and sustained mobility. The company invests in research and development in order to offer the most advanced and highest quality products. It shows its concern for the environment by reducing environmental impact to a minimum ABOUT Wind power consists in transforming mechanical energy generated by wind into electrical energy by means of a rotor equipped with permanent magnets. Considering that wind is a free and unlimited resource, the Windera S solution capitalizes on terrain use to obtain the most from it. The main components of a small wind power system as follows: Wind tower with a patented, innovative design. Electricity generator. Connection to the grid by means of the corresponding converter. Monitoring system. Emergency braking system. The geometrics used by Windera have been designed to obtain maximum energy yield at wind speeds of between 4 and 10 m/s, with minimum noise. Although the equipment involved is complex and large, Ennera guarantees safe and efficient installation, operation and maintenance WINDERA S Windera In: This product model allows self-consumption of the generated energy. It provides the option of connecting the installation in such a way that all the generated energy is reverted to the electrical grid of the home or business. 5

6 ADVANTAGES OF SMALL WIND TURBINE 2. ADVANTAGES OF In addition to economic advantages, wind power implies significant environmental benefits because it is clean and environmentally friendly. These small wind power turbines do no emit radiation or interfere with their settings; their noise emission does not disturb the tranquility and rest of either people or animals. In sum Windera is an innovative technological and environmental solution that goes hand-in-hand with the sustainability of the Earth, while obtaining the advantages inherent to generating one's own electricity. With a hypothetical mean annual wind speed of 5 m/s at a height of 12 m over its foundation, the Windera S small wind turbine, with a nominal power of 3.2 kw, can reduce CO2 emissions by 3 tonnes per year. 6

7 IMPORTANT SAFETY INSTRUCTIONS 3. IMPORTANT SAFETY INSTRUCTIONS The Windera system has been designed with your safety in mind. The Ennera team has given special priority to designing its small wind turbine to comply with all safety regulations applicable to this type of machinery, as regards both its mechanical and electrical features. The system is equipped with overspeed protection to ensure that the small wind turbine does not exceed its maximum rate of rotation, along with 50 alarms for early detection of failures and anomalies. These alarms are classified according to their severity and return the turbine to safe operation. The alarms are also reported to a remote monitoring centre from where maintenance tasks are organised. According to standard IEC , the maximum wind speed that a Class III small wind turbine should bear is 52.5 m/s. Nonetheless, there are inherent dangers to any electrical or mechanical devices. It is necessary to be aware at all times of both electrical and mechanical dangers as well as the danger posed by blade rotation and the following precautions should be taken: WHENEVER ACCESSING THE ROTOR, IT MUST BE IN EMERGENCY STOP STATUS. THE STRUCTURE OF THE SMALL WIND TURBINE SHOULD BE HANDLED ONLY BY TECHNICAL PERSONNEL. MAKE SURE THAT THE TOWER IS GROUNDED AND THAT GROUNDING COMPLIES WITH THE REQUIREMENTS IN THE LV MANUAL. Mechanical hazards: Blade rotation presents a very serious mechanical hazard. The rotor blades can reach speeds up to 280 rpm, which are capable of inflicting severe injuries and damage. DO NOT ACCESS THE ROTOR IF THE TURBINE IS IN OPERATION. Electrical hazards: The converter is an electrical device that operates at low voltage; the electrical hazards listed below for this type of voltage should be heeded: 7

8 IMPORTANT SAFETY INSTRUCTIONS SYMBOL MEANING DANGEROUS ELECTRICAL VOLTAGE WARNING THE INVERTER OPERATES AT HIGH VOLTAGES. ALL THE ELECTRICAL WORK ON THE INVERTER MUST BE PERFORMED BY QUALIFIED ELECTRICAL INSTALLERS. HOT SURFACE WARNING. THE INVERTER CAN HEAT UP DURING OPERATION. DO NOT TOUCH THE INVERTER WHILE IT IS IN OPERATION. HEED ALL THE DOCUMENTATION SUPPLIED WITH THE INVERTER. Low voltage electrical hazards can be caused by the following factors: Two active conductors (phase-phase or phase-neutral) can short-circuit and act as a receiver connection. Active and ground conductors can jump, either by direct contact with an active conductor or indirect contact via a mass that is energised due to poor isolation: Direct contacts: These are contacts with the active parts of the equipment that are designed to conduct electricity (cables, plugs, busbars, sockets, etc.). Indirect contacts: These are caused by touching certain parts that are not normally designed to conduct electricity, but can be energised due a defect of some kind (metal parts or masses of equipment or accessories). A mass is subjected to the power difference between two masses or electricity-conducting components at different voltages. Make sure that the converter is grounded to ensure protection against indirect electrical contact. 8

9 DECLARATION OF CONFORMITY WITH STANDARDS 4. DECLARATION OF CONFORMITY TO STANDARDS 4.1. TURBINE-RELATED STANDARDS IEC , Wind Turbines. Part 2: Design requirements for small wind turbines. The international standard IEC covers quality assurance features as well as the specific safety requirements for small wind turbines, including design, installation, maintenance and operation in specific outdoor conditions. British Wind Energy Association: Small Wind Turbine Performance and Safety Standard, 29 February MCS (Microgeneration Certification Scheme) Testing of Wind Turbine. Eurocode 3. Design of steel structures DS/ENV CONVERTER-RELATED STANDARDS CE Marking MQ Directive: IEC , Wind Turbines. Part 2: Design requirements for small wind turbines. Connection to the grid: Engineering Recommendation G83. Recommendations for the connection of small-scale embedded generators (up to 16 A per phase) in parallel with public low-voltage distribution networks. ENA (Energy Networks Association). VDE : Automatic disconnection device between a generator and the public low-voltage grid. UNE-EN-50438: Requirements for the connection of small-scale generators in parallel with public lowvoltage distribution networks. CE Marking EMC Directive: EN : Electromagnetic compatibility (EMC). Part 6-2: Generic standards. Immunity in industrial environments. EN : Electromagnetic compatibility (EMC). Part 6-3: Generic standards. Emission standard for residential, commercial and light industrial environments. EN : Electromagnetic compatibility (EMC). Part 3-2: Limits. Limits for harmonic current emissions (equipment input current <= 16 A per phase). EN : Electromagnetic compatibility (EMC). Part 3-3: Limits. Limitation of voltage changes, voltage fluctuations and flicker in public low-voltage supply systems for equipment with rated current <= 16 A per phase and not subject to conditional connection. CE Marking Low-voltage Directive: EN 50178: Electronic equipment for use in power installations. Labels: There are different labels to measure noise and efficiency levels of the wind turbine so they can be easily compared to other wind turbines. The first label corresponds to the BWEA (British Wind Energy Association), Small Wind Turbine Performance and Safety Standard. 9

10 DECLARATION OF CONFORMITY WITH STANDARDS Figure 1. BWEA label: Noise levels. This graph shows the noise level in relation to the distance the subject is at, as well as the wind speed registered in the hub. The previous graph shows that noise perception decreases as the distance increases. The green area shows noise levels below 40 db(a). The standards for maximum noise emission can vary according to the location because these are generally set by the local authorities. In general terms, it is less likely for permission to be given for an installation located in the red area. The locations that satisfy green area requirements are acceptable. Terrain located in the orange band may or not be acceptable depending on a variety of factors, such as local or national legislation. The points of reference of the noise marked in this map are 40 and 45 dba, since these are generally significant levels for planning wind power projects. The following table shows the noise levels associated with a variety of daily activities. 10

11 DECLARATION OF CONFORMITY WITH STANDARDS Figure 2. Noise levels: Daily activities. Source: AWEA (American Wind Energy association, On the other hand BWEA has developed a label for annual energy production; this label indicates the energy for a mean annual wind speed of 5 m/s. 11

12 DECLARATION OF CONFORMITY WITH STANDARDS Figure 3. BWEA label: Energy certificate. In addition, the International Energy Agency (IEA) has proposed a guide of recommended practices and tasks to be drawn up by a group of experts from Sweden, Ireland and Spain, among others. Thus, a label has been developed based on existing IEC standards accepted world-wide, instead of developing new standards that can only be applied in certain countries. This label provides noise emission, performance and design safety information that is independent and easy to compare. 12

13 DECLARATION OF CONFORMITY WITH STANDARDS Figure 4. IEA Label: Noise emission, performance and design safety. 13

14 WARRANTY 5. WARRANTY Your Windera S installation meets the highest quality standards. The warranty period is subject to compliance with the conditions and instructions specified in the warranty contract. The warranty conditions indicated in this section are of an explanatory nature. The general warranty conditions must be consulted in the warranty contract WHAT DOES IT INCLUDE? The installation, including all the components, is free of manufacturing and installation defects. If this is not the case, Ennera agree to replace any defective components free of charge for the user. Our technicians or an authorised service centre will decide which part or parts are defective. It is guaranteed that the power curve will not deteriorate further than established in the warranty contract under normal operating conditions and following the maintenance recommendations included in the manuals. Ennera reserves the right to replace or modify any of the parts if it deems it necessary to do so. Access to the monitoring service of the facility WHAT IS NOT INCLUDED? Damage by lightning. Damage by extremely high winds. Extremely high winds are considered as those that exceed 52.5 m/s at the height of the Class III hub, in accordance with IEC In principle, these gusts are rare in 50 year periods in Class III environments with a mean speed of 7.5 m/s at the height of the hub (IEC ). Grid-related disruptions outside the ranges considered as normal grid disruptions in EN Blade damage due to contact with other objects. Damage caused by improper use of the facility or product. Breakage due to mistreatment and equipment with proof of tampering LIMITATIONS AND EXCLUSIONS Nobody shall have authorisation to make changes to this warranty. All warranties applied to Ennera products are limited to the time period and conditions that appear in the warranty document. This warranty applies to the original purchaser and can be transferred. 14

15 WARRANTY 5.4. CUSTOMER RESPONSIBILITIES All Ennera products must be installed and handled according to the user, product and installer manuals and according to local engineering codes. If the turbine design is modified in any way, this will automatically render the warranty invalid and compromise the safety of the product. The company recommends that the purchaser keep a copy of the invoice or cancelled cheque to certify the date of purchase. Once the warranty expires, Ennera recommends that it be extended so the user can continue benefiting from the complete services offered by the company, including access to monitoring and maintenance. This will achieve maximum yield of the facility throughout its useful life. For any other problems, doubts or suggestions, please contact Ennera at the toll-free number: or via at [email protected] 15

16 SYSTEM DESCRIPTION 6. SYSTEM DESCRIPTION 6.1. SMALL WIND TURBINE COMPONENTS Figure 5. Windera Small Wind Turbine. 16

17 SYSTEM DESCRIPTION Front cone The front cone is a shell coupled to the hub and the bases of the blades. Its purpose is to protect the hub and blade stems from adverse weather conditions and to allow smooth wind entry at the base of each blade. Figure 6. Front cone. 17

18 SYSTEM DESCRIPTION Rotor The rotor system consists of three blades manufactured by a manual sheeting process with composite materials. Specifically, the blades consist of a polystyrene core and outer sheeting composed of fibreglass, carbon fibre and epoxy resin. Both the process and the materials that are used achieve very rigid, low-weight blades at all times. The blades convert wind power into rotating energy that acts on the generator shaft. They use the same aerodynamic principle as the wings of an airplane. The wind passes along the aerodynamic profile, generating high pressure on the lower part of the blade and low pressure on the upper part. The difference in pressure generates a rotating torque in addition to the force exerted on the rotor. Figure 7. Rotor. 18

19 SYSTEM DESCRIPTION The aerodynamic design of the Windera S blades is a combination of an aerodynamic profile that is especially adapted to the operating parameters for blades of this size and a blade geometry that seeks to optimise the power produced at moderate wind operating ranges. The result is a blade that has proven to be extremely efficient in both wind tunnel tests and tests performed in the field. Moreover, the rotor blades have an aerodynamic tip at the end (winglet) designed to reduce power loss at the wing tip, thus increasing generated power without increasing blade diameter. The winglets are easy to distinguish due to their similarity with those on airplane wings. The blades are firmly attached to the generator shaft by means of the hub. Each set of 3 blades is carefully manufactured to maintain the rotor in complete equilibrium and thus guarantee optimal operation of the Windera S small wind turbine Technical specifications Configuration... Upwind Pitch...Fixed Orientation...Free yaw moved by streamlined vane Blade diameter m Swept area m 2 Material...Carbon fibre, fibreglass and epoxy Process... Manual sheeting Start-up wind speed m/s Cut-out wind speed m/s Maximum wind speed...25 m/s In the event of wind speeds in excess of 25 m/s, Windera performs a controlled safety stop. 19

20 SYSTEM DESCRIPTION Hub The hub is the part of the rotor system where the blades are inserted. The hub, located at the front of the wind turbine, is the element on which the 3 blades are supported. As it is not equipped with a gearbox, it is connected directly and transmits the wind torque generated by the wind through the blades to the generator shaft. The hub is made of aluminium so it is very lightweight, but strictly calculated to operate in extreme wind conditions. Figure 8. Hub. 20

21 SYSTEM DESCRIPTION Generator The generator converts the rotation energy produced by the rotor system into electrical power. This component is essential for the Windera S to be efficient and effective, since the efficiency of the energy transformation depends on it. The generator design provides high electrical performance and a short start-up torque. This has all been achieved by designing a permanent-magnet generator with an optimised pole-slot configuration and the use of low-friction ball bearings. The number of magnets is always even and they move evenly in a circle so the poles are magnetically alternated. The generator is designed to produce the maximum amount of energy; its smooth start-up with minimal resistance allows the wind turbine to continue producing electricity even at low wind speeds. The choice of a permanent-magnet generator has the advantage of producing energy whenever the rotor system is rotating, regardless of how low the rotation speed is. Since it is capable of producing energy at low wind speeds, it eliminates the need to equip the Windera S with a gearbox that increases the revolutions of the blade-hub unit. On the other hand, slow rotation speeds reduce both mechanical stress and noise emissions. In addition, the generator can exert its own braking force, activated by the converter when wind speeds are too high. This brake is called a Crowbar brake. Finally, the manufacturing process of the stator provides perfect cooling properties that contribute to increase the performance of the Windera S. Figure 9. Generator Technical specifications Normal temperature range...-10ºc to +45ºC in nacelle Rated speed rpm Braking torque x Tnom (approx.) Maximum speed rpm 21

22 SYSTEM DESCRIPTION Centrifuge brake The centrifuge brake is a redundant safety device that stops the wind turbine in the event of emergencies. The braking action is performed by moved by the centrifugal force of ferodo brake pads that press against the drum when speed is at a maximum. This friction causes the system to lock and the wind turbine to stop. Once the turbine has stopped, the pads return to their initial position and the wind turbine is braked by the crowbar. The brake can be activated in the event of failures in the electrical grid or other abnormal emergency conditions in the system. It is a redundant speed protection, since the crowbar is capable of stopping the wind turbine by itself under normal operating conditions. System failures at very high wind speeds or a failure in the crowbar system can activate the centrifuge brake. In normal conditions, the wind turbine is stopped by the electrical brake. If the wind conditions are such that the electrical brake is not capable of braking the turbine, the centrifuge (mechanical) brake prevents it from exceeding the maximum design speed and brings it to a stop. Figure 10. Centrifuge brake. 22

23 SYSTEM DESCRIPTION Vane The vane is the component that orients the turbine towards the wind. It consists of a single part that is firmly attached to the generator shell. As in most wind turbines with a horizontal shaft, it rotates around a bearing to face the wind. The orientation axis is the vertical line that passes through the centre of the bearing and coincides with the tower axis. Due to the small dimensions of the wind turbine, there is not enough space to house transmission mechanisms and electrical motors that orient the rotor to face the wind. This is why the Windera S orientation system consists of a vane so the wind can impel the blades from the front (upwind). Its innovative single-part design avoids the need for gaskets, nuts and bolts, thereby increasing the aerodynamic properties of the whole. The vane is located at the end of a rod and the wind exerts a lateral force on it to turn the turbine so that it faces the wind. The moment affecting the vane is simply the lateral force multiplied by the length of the rod. The lateral force is the result of the surface area of the vane and the wind speed squared. Figure 11. Vane. 23

24 SYSTEM DESCRIPTION Yaw System The Yaw unit is the system that contains the components that make it possible for the nacelle to rotate around the tower axis in order to position itself facing the wind. The rotating system (Yaw) is found on all wind turbines. However, while large wind turbines have complex systems consisting of gears and hydraulic systems, small turbines are generally equipped with passive systems. This is the case of the Windera S. The Yaw system and the vane are key elements in obtaining maximum efficiency, since they allow the wind turbine to position itself with minimum turbulence and the rotor to draw the maximum power from the wind. The system consists of the following components: Yaw shaft. Yaw chassis. Set of yaw bearings. Slip ring collector. Set of silent blocks. The slip ring collector consists of a set of 4 rings and 8 brushes of simple design. The low operating speeds of the yaw allow the use of silver-graphite brushes with low contact resistance and reduced wear throughout their service life. The yaw chassis allows access to the collector to check wear conditions during scheduled maintenance tasks. The yaw is attached to the tower by a bolted connection separated by a set of silent blocks. The silent blocks isolate the support structure from the vibrations in the nacelle, thus contributing to lower mechanical noise. Figure 12. Yaw System. 24

25 SYSTEM DESCRIPTION Tower The tower is the structure that supports the turbine. It is 12 metres high and capable of withstanding extreme wind conditions. It has been designed according to the load criteria found in standard and the guidelines found in the Eurocode for support structures. It is made of galvanised steel sections that not only add to its elegance but protect it against adverse weather conditions. The tower consists of 4 sections with a total length of 12 metres once they are assembled. The sections can be transported by 2 or 3 people without the need for cranes or external equipment. The sections are assembled on top of each other, applying contact pressure between sections to ensure that each section inserts perfectly into the previous one. It is also equipped with a guide system at the base to facilitate lowering the wind turbine during assembly, disassembly or maintenance tasks. A hoisting and lowering system can also be mounted on the inside of the tower to facilitate installation, uninstallation and maintenance, without the need to use cranes. This significantly reduces customer expenses, increases profitability and allows assembly in areas that are difficult to access. Figure 13. Tower Technical specifications Height...12 m Material... Steel Composition...Sections 25

26 SYSTEM DESCRIPTION Converter The electrical energy that exits the generator (alternate current) does not meet the specifications required to be injected directly into the grid. Therefore, it has to be transformed into consumption parameters by a frequency converter. Ennera has designed and developed a converter that adapts the electrical energy from the generator into grid conditions (230V and 50 Hz). The design of the generator-converter unit optimises production throughout the operating process. Improved performance is obtained by eliminating the transformer This guarantees isolation by means of active monitoring of possible failures and reducing the direct current component injected into the grid to a minimum, thus complying with the requirements established by regulations governing grid connection. The converter includes detailed control software that ensures that the rotation speed of the blades is always optimal for production and loads. The design also ensures that power production can commence at very low rotation speeds and detects wind speeds that are too high to produce power. All this is achieved without the need to include anemometers or rotation speed sensors. In the wind turbine design, the converter is located at the foot of the turbine to prevent vibrations and high temperatures. Thus, the useful life of the converter is extended. The converter not only controls turbine operation, but also stores the registry of failures and communicates the information needed by the user and the installer through the monitoring centre. 26

27 SYSTEM DESCRIPTION Figure 14. Converter architecture and assembly Technical specifications Temperature range...-10ºc to +45ºC Nominal power kw Rated voltage V Rated frequency...50 Hz; THD < 2% Maximum yield... 95% 27

28 SYSTEM DESCRIPTION Monitoring and communications The monitoring and communications system is the centre of operations of the installation. Its purpose is to provide customer access at all times to the operation information of the installation. All this information is sent by a modem installed in the converter, through the converter antenna using a GPRS protocol to a website protected by a password. The three main areas of information included in the monitoring centre are as follows: Financial. Meteorological. Technical and environmental Financial information The financial information can be daily, weekly, monthly, annually and accumulated from the beginning. The data visible to the customer are as follows: Accumulated savings in euros: The customer will be able to see how much money he is saving each year (self-consumption or net metering) and income (FIT). Accumulated payback: A graph will display the percentage of the initial investment that has been amortised Weather information This monitoring and communications application shows the weather forecast for the next few days. The following information is available: Average wind speed. Wind direction. Temperature (Celsius). Solar radiation. Cloud cover. Precipitation. Atmospheric pressure. 28

29 SYSTEM DESCRIPTION Technical and environmental information TECHNICAL INFORMATION The technical information available to the customer is as follows: Wind turbine information (name, serial number, installation date, power installed, years of warranty, etc.). Power generated: This information is obtained from the monitoring centre's database (in kwh) accumulated over a variety of time periods. A table will be displayed with the mean consumption of the home/firm as a reference. Energy independence. Operation: Graphs will show the various operating modes that are recorded in the monitoring centre ENVIRONMENTAL INFORMATION Lastly, the customer will have the necessary environmental information available at all times: CO2 saved daily, weekly, monthly, annually and accumulated. Car-equivalent (km driven). Tree-equivalent: The customer will be able to add trees to "his" mountain; that is, the drawing of a mountain in his customer area will be gradually filled with trees. 29

30 SYSTEM DESCRIPTION 6.2. OPERATION Wind power consists in obtaining electrical energy from mechanical energy generated by the effect of wind on the blades. The Windera S small wind turbine is a system of blades coupled to a rotor with permanent magnets. Under the effect of the wind, the blades rotate jointly with the rotor, generating a mechanical movement that produces electrical energy by interacting with the magnetic field created by the magnets. As its function indicates, this system is called generation. The installation is connected to the electrical grid, so it requires a converter to adapt the properties of the generated power to those of the grid. It also has an antenna to transfer information to the website by means of GPRS communications. Thanks to the Windera S system, the generated energy is transported through the grid to the user's home or company. The following figure shows a diagram of how the Windera S operates. Figure 15. Windera system operation. For customer convenience, the small wind turbines are equipped with a monitoring system that provides efficient management and monitoring of the installation. Ennera operators have access to the system via the web environment, so they can know the condition of the components at all times and whether maintenance tasks are required. In addition, the system is equipped with an emergency braking system that is used to stop the rotor blades safely to avoid materials from being damaged or people from being injured. 30

31 SYSTEM DESCRIPTION The Windera S small wind turbine is designed to operate without user revision. If the system detects any problems, it will shut down automatically, so it can be left unattended. In case the user wants to stop the Windera S, the converter has 2 buttons for that: Controlled stop button and emergency stop button. Figure 16. Controlled stop button (left) and emergency stop button (right). The user can stop the Windera S with any of those buttons. The emergency stop is faster than the controlled stop. The overspeed protection ensures that the small wind turbine does not exceed the maximum rotation speed under high wind speed conditions. These conditions are specified in standard IEC for Class III small wind turbines (reference wind speed 37.5 m/s and 50-year gust of 52.5 m/s at hub height). Emergency braking works at three levels: In the event of wind gusts: The control adjusts the speed, reducing blade rotation speed and aerodynamic torque. In the event of wind speeds that are too high to produce power: The control adjusts the turbine to a controlled number of revolutions. Once the rotation speed has been reduced, the electrical brake is activated, taking the small wind turbine to idling speed at which it can withstand the wind loads safely. In the event of failures in the electrical grid or other abnormal system conditions: A redundant speed protection is enabled, consisting in a combination of electrical braking and the patented mechanical centrifuge braking system. The electrical brake is activated first. If the wind conditions are such that the electrical brake is not enough to stop the turbine, the centrifuge brake is activated; this prevents the turbine from exceeding the maximum design speed and stops it in safe conditions Emergency stop By pressing the emergency stop button at the converter front the turbine produces an emergency shutdown. A short circuit in three phases of the generator will stop the turbine. The turbine is not blocked; it can be rotating at very low rotating speed Controlled stop The purpose of the controlled stop is to stop the wind turbine smoothly and safely without overloading any of the Windera S components. The rate of rotation speed reduction applied to the turbine is 10 rpm/s. Wind turbine speed slows gradually until it is practically stopped. This is when the electrical brake is activated (generator short-circuit), with the purpose of stopping the turbine completely or letting it rotate at idling speed and remain in those conditions. 31

32 SYSTEM DESCRIPTION The control system of the Windera S can protect the wind turbine from working at high winds. There is an algorithm that detects the high wind speeds and in this case, the control stops the turbine and electrical brake is activated. In case of very high wind speeds, if the electrical brake is not able to stop the turbine, there is a centrifugal brake that will stop the turbine. In case of emergency, the Windera S can be stopped by either using the controlled stop button or emergency stop button. Figure 17. Controlled stop push button WINDERA S GENERAL SPECIFICATIONS Type... Upwind connected to grid Generator...Permanent high-efficiency magnets Rotation speed range rpm Grid connection...single-phase AC 230 V to 50 Hz Power at nominal wind speed kw Temperature range...-15ºc to +45ºC Start-up speed m/s Cut-out speed m/s Nominal wind speed m/s Maximum operating speed...25 m/s Emergency braking system...electrical and centrifuge brake Blades...3 carbon fibre, fibreglass and epoxy blades Tower...12 m Rotor diameter m Orientation system...passive with vane Rotation speed control...variable speed with electronic control 32

33 COMPETITIVE ADVANTAGES AND INNOVATIONS 7. COMPETITIVE ADVANTAGES AND INNOVATIONS 7.1. COMPETITIVE ADVANTAGES The advances in the wind power market in recent years have achieved a marked improvement in wind turbine performance, along with a reduction in the cost of the power generated; to this, Windera small wind turbines add the following advantages versus the competition: Windera small wind turbines require very little maintenance because they are monitored from a web environment by Ennera operators. Thus, they can operate for long periods of time without any interruptions. The innovative design of the Windera small wind turbine achieves lower noise emissions than other small wind turbines. The Windera system has 400 configurable parameters that obtain optimum yield from available wind power INNOVATIONS The blades are designed with technology used in the aeronautical sector to increase efficiency. The winglet on the rotor blades reduces aerodynamic resistance and therefore increases the available wind power. Optimal control to make the most of the wind power. The Windera monitoring system can be used to display and manage the operation of the Windera S and to know the amount of energy being generated at all times. The customer can find all kinds of parameter values, both current and historical through the on-line application. There are 50 alarms for early detection of failures and anomalies. 33

34 INSPECTIONS AND MAINTENANCE 8. INSPECTIONS AND MAINTENANCE Although the small wind turbine is monitored at all times by Ennera operators from the web environment to perform required maintenance tasks, the reliability and features can be improved by regular inspection of the system. The maintenance of the Windera S wind turbine must be carried out by trained personnel only. The following safety measures must be taken into consideration before performing an inspection: DO NOT MANIPULATE THE STRUCTURE OF THE SMALL WIND TURBINE IN THE EVENT OF A BREAKDOWN. IF A PROBLEM IS DETECTED, CALL THE TECHNICAL SERVICE. DO NOT PERFORM INSPECTIONS IN ADVERSE WEATHER CONDITIONS OR WHEN WIND SPEEDS EXCEED 10 M/S. Before performing inspections, refer to Table 1, which lists the most common problems that can occur in the small wind turbine VISUAL INSPECTIONS The following steps should be taken when a visual inspection is requested: 1. Shut down the small wind turbine. 2. Perform a visual inspection in search of serious notches and cracks in the blades and winglet. If there are conspicuous cracks or notches on the blades, these can cause serious damage and failures in the turbine. If the blades are damaged, call the customer service. 3. Inspect the tower and structure of the small wind turbine to check for structural damage or loose parts. If the structure of the small wind turbine is damaged, call the customer service. 4. Start up the small wind turbine again. 34

35 INSPECTIONS AND MAINTENANCE 8.2. NOISE INSPECTIONS 1. Operate the small wind turbine at nominal speed and check that it does not emit mechanical noises such as metallic banging or rattling. 2. Make sure that none of the components are subject to notable vibration. The turbine should operate smoothly and free of disturbances. If strange noises or strong vibrations are detected, shut down the small wind turbine and call the customer service MAINTENANCE Although the Windera S has been designed for a service lifetime of 20 years, Ennera Energy and Mobility recommends Windera S wind turbine be checked on an annual basis to make the maintenance procedure. The maximum wind under which the maintenance procedure may be carried out is Vmaint= 10 m/s. The design of the Windera S wind turbine includes simple, robust components in order to minimise maintenance tasks during its useful life. Nonetheless, the environmental and electrical connection conditions can vary greatly from one site to another. Therefore, Ennera has established a proactive process that maximises the profitability of the installation. The first phase consists of a periodical check by an operator who visits the installation, which is covered by the warranty. In addition, if the installation requires an inspection due to poor conditions detected by the monitoring centre or the user, the technical team will get in touch with the user to agree on a date to perform the revision, as established in the maintenance contract. Wind turbine operation will be monitored by the monitoring centre to know the status of the turbine at all times and access the history log of registered alarms. Our technicians can use the communications module to access the installation remotely, analyse its status and organise any corrective measures that may be required. This process minimises operational costs by using preventive maintenance to reduce breakdowns, early remote analysis to reduce repair times and thus maximise installation production times. Proper maintenance is essential in a product with a useful life of 20 years and the corresponding time intervals will depend on the characteristics of the installation site. The Ennera website provides further information on maintenance of the Windera S. If you have any questions or suggestions, please do not hesitate to call Ennera at the toll-free number: or contact us via at [email protected]. For further information on recommendations for maintenance, please refer to the installation and maintenance manual. 35

36 TROUBLESHOOTING 9. TROUBLESHOOTING The following precautions should be taken before taking any specific troubleshooting measures: DO NOT MANIPULATE THE STRUCTURE OF THE SMALL WIND TURBINE UNDER ANY CIRCUMSTANCES. IF A PROBLEM IS DETECTED, CALL THE TECHNICAL SERVICE. The following table shows the most common problems that can occur in small wind turbines, as well as their causes and how to solve them. THE SMALL WIND TURBINE REMAINS STILL ALTHOUGH THERE IS WIND. Table 1 Problem detected Possible cause Solution THE EMERGENCY BRAKE HAS BEEN ACTIVATED, DUE TO: THE SMALL WIND TURBINE MAKES OCCASIONAL MECHANICAL NOISES. THE SMALL WIND TURBINE MAKES AN UNUSUAL NOISE, SUCH AS WHIS- TLING OR BUZZING. THE ROTOR IS OFF BALANCE, CAUS- ING THE TURBINE TO MOVE SLIGHTLY BACK AND FORTH. THE TURBINE RATTLES DURING RO- TATION, ESPECIALLY AT LOW SPEEDS. TEMPORARY ADVERSE WEATHER CONDITIONS. FAILURES IN THE ELECTRICAL GRID OR OTHER ABNORMAL SYSTEM CONDITIONS. FRICTION BETWEEN COMPONENTS OR DAMAGED BEARINGS CAN CAUSE VIBRATIONS AND EXCESS LOADS. ROTOR BLADES DAMAGED. BLADES DAMAGED. BEARINGS DAMAGED. ROTOR MISALIGNED. WAIT UNTIL THE WEATHER CONDI- TIONS IMPROVE AND CHECK THAT THE BLADES OF THE SMALL WIND TURBINE START ROTATING AGAIN. IMPLEMENT A CONTROLLED STOP OF THE CONVERTER AS INDICATED IN SECTION AND CALL THE CUS- TOMER SERVICE. IMPLEMENT A CONTROLLED STOP OF THE CONVERTER AS INDICATED IN SECTION AND CALL THE CUS- TOMER SERVICE. IMPLEMENT A CONTROLLED STOP OF THE CONVERTER AS INDICATED IN SECTION AND CALL THE CUS- TOMER SERVICE. IMPLEMENT A CONTROLLED STOP OF THE CONVERTER AS INDICATED IN SECTION AND CALL THE CUS- TOMER SERVICE. THE ROTOR ROTATES VERY SLOWLY. THE ROTOR DOES NOT TURN. ICE ACCUMULATED ON THE BLADES. SHORT-CIRCUIT BRAKE ACTIVATED DUE TO GRID FAILURES OR OTHER ABNORMAL SYSTEM CONDITIONS. SHORT-CIRCUIT BRAKE ACTIVATED DUE TO HIGH WIND SPEEDS. MECHANICAL FAILURE IN THE ALTER- NATOR. WAIT UNTIL THE WEATHER IM- PROVES. IMPLEMENT A CONTROLLED STOP OF THE CONVERTER AS INDICATED IN SECTION AND CALL THE CUS- TOMER SERVICE. WAIT UNTIL THE WIND SPEED DROPS AND CHECK THAT THE BLADES OF THE WIND TURBINE START ROTATING AGAIN. IMPLEMENT A CONTROLLED STOP OF THE CONVERTER AS INDICATED IN SECTION AND CALL THE CUS- TOMER SERVICE. 36

37 FREQUENTLY ASKED QUESTIONS 10. FREQUENTLY ASKED QUESTIONS GENERAL QUESTIONS Can the small wind turbine be left unattended? Yes, the small wind turbine is designed to operate without user revision. If the system detects any problems, it will shut down automatically. Are small wind turbines noisy? The Windera S small wind turbine emits noise within acceptable ranges, since its nominal rotation speed is between 50 and 230 rpm. For how long do small wind turbines produce electricity? This depends largely on the chosen installation site, mean wind speed and how constant the wind is. In an adequate installation site, a small wind turbine produces electricity 75% of the time, although not always at nominal power. In a normal year, it produces 20% to 30% of the electricity produced at nominal power operating non-stop. This value is known as the capacity factor. How long does a small wind turbine last? The Windera small wind turbine is designed to last for more than 20 years. This is due to its robust design, the quality of its materials and anti-corrosion treatments and to a totally sealed design that prevents humidity and particles from entering the system. Can birds fly into small wind turbines? It is highly improbable that a bird will fly into the blades of the Windera small wind turbine because migrating flocks fly at greater heights during their journeys TECHNICAL QUESTIONS How does a small wind turbine work? The blades use the force of the wind to generate a mechanical torque in the generator, which in turn generates three-phase electricity depending on the rotation speed and the force exerted on its shaft by the blades. The electricity generated passes to the converter and is transformed into single-phase electricity so that it can be injected into the electrical grid in low-voltage distribution conditions. Is it necessary to install protection between the small turbine and the converter? Never, the converter performs all the necessary protection functions. If a protective measure is installed between the turbine and the converter and it causes the electrical connection to cut off, the turbine will continue to operate in no-load mode, causing irreparable damage to the small wind turbine. How do I know the power being delivered by the small wind turbine? You can find out the power being delivered by the wind turbine by accessing the monitoring web environment. What is the maximum wind speed that the small wind turbine can withstand? Should the system be shut down during a storm? The Windera S small wind turbine is designed to operate unattended in storm conditions thanks to its control system and overspeed protections. 37

38 RECYCLING 11. RECYCLING Ennera will make the necessary repairs throughout the useful life of the Windera S. If any of the components require replacement, our technicians will collect the old component and ensure that it is disposed of properly. In accordance with European Directive 2002/96/CE regarding electrical and electronic device waste and its application in Spanish law, used electrical devices must be collected separately and recycled in an environmentally friendly manner. Therefore, when the time comes, please contact the local authorities responsible for proper waste disposal and ensure that the entire turbine is disposed of correctly. The Windera S is designed and manufactured according to European Directive 2002/95/ CE (RoHS), so it does not contain hazardous substances. Directivr 2002/95/CE (RoHS) restricts the use of lead, mercury, cadmium, hexavalent chromium, PBB (polybrominated biphenly) and PBDE (polybrominated diphenyl ethers). Avoid possible environmental and health hazards by disposing of this product adequately. Recycling of materials will benefit the preservation of natural resources. 38

39 ANNEXES 12. ANNEXES ELECTRICAL CONNECTION DIAGRAM Figure 18. Single line electrical diagram. 39

40 ANNEXES GENERAL DIMENSIONS DRAWING Figure 19. General dimensions in mm. 40