Inverter and programmable controls in heat pump applications

Transcription

1 Inverter and programmable controls in heat pump applications Biagio Lamanna Application Competence Centre Manager Product Development Process CAREL INDUSTRIES Srl 3rd EHPA European Heat Pump Forum Brussels

2 Summary Why BLDC inverter compressors? Compressor motor technologies Partial load and seasonal efficiency Carel pcosistema+ for HP application Ready to use solution approved by the compressor manufacturers Full customizable hardware and software Features & Benefits of an integrated solution VS a stand alone inverter Conclusions (for CAREL algorithm details see the end of the presentation) Page 2

3 What does BLDC means? BLDC (brushless direct current) motor BPM (brushless permanent magnet) motor DC (direct current) inverter IPM (interior permanent magnet) motor SPM (surface permanent magnet) motor EC (electronic controlled) motor Different NAMES for the SAME technology Page 3

4 Why BLDC inverter compressors? Electric motor evolution: AC asynchronous induction motor Both compatible with standard on-off technology and inverter use Good performances only for motors developed specifically for inverter use Energy waste due to the need to create the rotor magnetic field DC brushless motor (SPM) The rotor is a permanent magnet, there no energy waste The magnets of SPM motors need to be fixed on the rotor surface using adhesive, high speed is not allowed DC brushless motor (IPM) The magnets of SPM motors are inside the rotor Highest efficiency and performances High speed Requires a top level BLDC inverter Page 4

5 The motor structures of the IM (induction motor), SPM (Surface permanent magnets, IPM (Interior permanent magnets) Comparison table of IM, SPM and IPM motors Page 5

6 Why BLDC inverter compressors? The efficiency improvement of the brushless motor technology versus the induction motor can be estimated on 4-5% Confidential Page 6

7 Speed controlled BLDC compressors Scroll or twin rotary, up to 35kW cooling capacity, mainly R410a refrigerant, up to 65 C cond. temperature with no liquid injection Page 7

8 Why BLDC inverter compressors? New unit testing and rating procedures based on partial load and seasonal efficiency Page 8

9 Why BLDC inverter compressors? Variable speed compressors can match the partial load giving an extremely high unit efficiency due to the improved efficiency of the compressor at partial load as motor performance and basic COP Pressure Increased efficiency together with improved efficiency of both heat exchangers Enthalpy Page 9

10 Speed controlled BLDC compressors Unit performances with BLDC compressors Page 10

11 Speed controlled BLDC compressors Unit performances with BLDC compressors : n o i t duc e r t s o c y r g r a e e y n / E /kwh) (0.2 3rd EHPA European Heat Pump Forum Brussels Page 11

12 Page 12

13 Makes DC inverter technology available Page 13

14 pcosistema+: off the shelf technology Thanks to the experiences of CAREL Labs 1tool library provides a wide range of turn key solutions to make DC inverter technology available to heat pump manufacturers. Page 14

15 pcosistema+: off the shelf technology Development time for BLDC inverter compressor management: 8 months Page 15

16 pcosistema+: off the shelf technology Development time for EEV management: 3 months Page 16

17 pcosistema+: off the shelf technology Development time for brushless sensorless technology drive: 12 months Page 17

18 pcosistema+: off the shelf technology Page 18

19 pcosistema+: user interfaces range for deep customization Page 19

20 pcosistema+: wide range of programmable controllers Page 20

21 Complete HP control Page 21

22 Saving more than 40 development weeks Makes DC inverter technology available Page 22

23 Features & Benefits of an integrated solution Development time: months Page 23

24 Features & Benefits of an integrated solution Compressor safeguard Managed function Extra features Compressor start up procedure Compressor working envelope Compressor timings Compressor minimum pressure drop Suction superheat Discharge superheat Discharge gas temperature Page 24

25 Features & Benefits of an integrated solution Unit safeguard and performance Managed function Compressor start failure management Compressor equalization at start-up Drive alarm management Speed regulation according to the application needs Drive parameter pre-set for different compressors Drive custom parameters load and save management Drive complete user interface Extra features Page 25

26 Conclusions Conclusions A BLDC inverter compressor unit: Has the top level compressor motor technology Meets all present and future efficiency rating specifications Grants high performances due to the wide range of cooling capacity modulation that allows the best application temperature control Page 26

27 Conclusions Conclusions A full integrated system for HP application: Meets ALL compressor manufacturer specifications (with their official approval!) Allows to use the compressor in the full speed range in all the working envelope conditions Avoids the unit OEM to spend months of R&D development Grants a full control on the unit with plenty of extra features compared with a stand alone inverter drive that allow to reach the best performance level Page 27

28 Conclusions Conclusions A full customizable system for HP application: Meets all unit manufacturer needs in terms of performance/cost compromise Allows the unit manufacturers to keep their knowledge about the application and customize any part of the software and user interface Has many user interface solutions for each different user profile Page 28

29 Inverter and programmable controls in heat pump applications THANK YOU FOR YOUR KIND ATTENTION Biagio Lamanna Application Competence Centre Manager Product Development Process CAREL INDUSTRIES Srl Page 29

30 CAREL control algorithm details Compressor working envelope: Min/Max compressor ratio Min pressure differential Max motor current Max/min discharge pressure Max/min suction pressure Max discharge temperature (different for each zone) Min/Max compressor speed (different for each zone) Different management for each compressor! Page 30

31 CAREL control algorithm details Compressor working envelope management: Unit capacity reduction by EEV control in case of low compressor ratio, high suction pressure, high motor current, etc Compressor capacity reduction in case of high discharge pressure and/or temperature, low suction pressure, etc Drive acceleration/deceleration ramp control to avoid going out from the safety working areas Page 31

32 CAREL control algorithm details Compressor windings temperature management: By means of measuring: compressor shell temperature compressor discharge gas temperature and superheat compressor motor current The control system can: stop the compressor due to high shell temperatures even if the drive can manage the compressor speed in case of high motor current without stopping it and both EEV and compressor control modules can regulate the discharge superheat or temperature for optimal compressor performance with maximum compressor speed by means of the safety liquid injection Page 32

33 CAREL control algorithm details Unit start-up management: The synchronization between compressor, drive and EEV management allows the take care of: Pressure differential before start Equalization, if needed or compressor start-up even with up to 10barg pressure difference. Pressure differential after start ( greater than the minimum allowed) Oil recovery after start Compressor warm up Compressor timings (minimum ON time, minimum OFF time, minimum time between different starts) Start-up quick retry in case of start failure Wrong wiring, blocked rotor, damaged motor windings, or any start-up problem. Page 33

34 CAREL control algorithm details Compressor alarm management: Centralized alarm management for all unit components: The unit can work even with broken probes Critical alarms manual reset by user interface or remote monitoring system Automatic to manual alarm reset after a defined number of attempts All alarms in the same UI: Unit alarms (i.e. low temperature, low water flow, high pressure, etc) Compressor alarms (i.e. high discharge temperature, out of envelope, low compressor ratio, etc.) Drive and motor alarms (i.e. high motor current, low supply voltage, communication offline, etc.) Valve alarms (i.e. stepper motor damaged, low suction superheat, etc.) Page 34