1、 2011 Standard for Performance Rating of Variable Frequency Drives AHRI Standard 1211 (SI) Price $10.00 (M) $20.00 (NM) Printed in U.S.A. Copyright 2011, by Air-Conditioning, Heating and Refrigeration Institute Registered United States Patent and Trademark Office IMPORTANT SAFETY DISCLAIMER AHRI doe
2、s not set safety standards and does not certify or guarantee the safety of any products, components or systems designed, tested, rated, installed or operated in accordance with this standard/guideline. It is strongly recommended that products be designed, constructed, assembled, installed and operat
3、ed in accordance with nationally recognized safety standards and code requirements appropriate for products covered by this standard/guideline. AHRI uses its best efforts to develop standards/guidelines employing state-of-the-art and accepted industry practices. AHRI does not certify or guarantee th
4、at any tests conducted under its standards/guidelines will be non-hazardous or free from risk. Note: This is a new standard. This standard seeks to provide an uniform method of measuring and comparing Variable Frequency Drives by establishing testing and rating requirements; specifically data requir
5、ements for Drive System Efficiency, Power Line Harmonics and Motor Insulation Stress. For I-P ratings, see AHRI Standard 1210 (I-P)-2011 TABLE OF CONTENTS SECTION PAGE Section 1. Purpose 1 Section 2. Scope . 1 Section 3. Definitions . 1 Section 4. Classifications . 2 Section 5. General Test Requirem
6、ents . 3 Section 6. Rating Requirements . 6 Section 7. Minimum Data Requirements for Published Requirements 6 Section 8. Marking and Nameplate Data 7 Section 9. Conformance Conditions. 7 TABLES Table 1A. Voltage Classes . 3 Table 1B. Power Classifications 3 Table 2. Speed/Torque Test Points for Driv
7、e System Efficiency and Motor Stress Insulation Tests 4 Table 3. Speed/Torque Test Points for Powerline Harmonics Test. 4 Table 4. VFD to Motor Conductor Sizes 5 Table 5. Reported Harmonic Current 6 APPENDICES Appendix A. References Normative 8 Appendix B. References Informative 9 Appendix C. Method
8、 of Testing Rating Variable Frequency Drives - Normative . 10 FIGURES FOR APPENDICES Figure C1. Test Set-up for Drive System Efficiency and Powerline Harmonics Test Methods 11 AHRI STANDARD 1211 (SI)-2011 1 PERFORMANCE RATING OF VARIABLE FREQUENCY DRIVES Section 1. Purpose 1.1 Purpose. The purpose o
9、f this standard is to establish for Variable Frequency Drives (VFDs): definitions; classifications; general test requirements; rating requirements; minimum data requirements for Published Ratings; marking and nameplate data; and conformance conditions. 1.1.1 Intent. This standard is intended for the
10、 guidance of the industry, including manufacturers, engineers, installers, contractors and users. 1.1.2 Review and Amendment. This standard is subject to review and amendment as technology advances. Section 2. Scope 2.1 Scope. This standard applies, within the heating, ventilating, air-conditioning
11、and refrigeration (HVACR) context, to VFDs used in the control of asynchronous induction motors. The range includes all those found within a building including: low voltage ( 600 V) and drives that are stand alone, not mechanically integrated into motors. 2.2 Exclusions. This standard does not apply
12、 to VFDs applied to motors other than those listed above. Section 3. Definitions All terms in this document follow the standard industry definitions in the current edition of ASHRAE Terminology of Heating, Ventilation, Air Conditioning, and Refrigeration unless otherwise defined in this section. 3.1
13、 Carrier Switching Frequency. The frequency at which the power output devices of a VFD are switched on and off. 3.2 Constant Torque (CT). Applications where the torque requirement of the driven load remains constant or nearly so over the normal speed range of use. Positive-displacement pumps and rec
14、iprocating compressors are examples of constant-torque loads. 3.3 Drive System Efficiency. Ratio of the output power from the motor to the input power of the VFD including motor and VFD losses. 3.4 Equipment Under Test (EUT). Test sample. 3.5 Motor Insulation Stress. The voltage stress placed on a m
15、otors insulation due to high Peak Voltages and short-rise times that occur when the motor is driven by a VFD. 3.6 Motor Thermal Equilibrium. When the observed temperature rise of the motor winding does not vary more than 1K over a period of 30 minutes, or when the observed motor frame or core temper
16、ature rise does not vary more than 1K over a period of 60 minutes. 3.7 Peak Voltage. The maximum instantaneous voltage measured at a motors terminals when operated from a VFD. 3.8 Percent Speed. The percentage of rated motor rpm as measured. 3.9 Percent Torque. The percentage of the motor rated Full
17、 Load torque. AHRI STANDARD 1211 (SI)-2011 2 3.10 Power Line Harmonics. Components of the power line voltage and current at the input of the VFD that are integer multiples of the fundamental sinusoidal frequency of the power source (example 60 Hz). 3.11 Published Rating. A rating of the assigned val
18、ues of those performance characteristics, under stated Rating Conditions, by which a unit may be chosen to fit its application. These values apply to all units of like nominal size and type (identification) produced by the same manufacturer. As used herein, the term Published Rating includes the rat
19、ing of all performance characteristics shown on the unit or published in specifications, advertising or other literature controlled by the manufacturer, at stated Rating Conditions. 3.11.1 Application Rating. A rating based on tests performed at application Rating Conditions (other than Standard Rat
20、ing Conditions). 3.11.2 Standard Rating. A rating based on tests performed at Standard Rating Conditions. 3.12 Rating Conditions. Any set of operating conditions under which a single level of performance results and which causes only that level of performance to occur (e.g. line voltage, ambient tem
21、perature). 3.12.1 Standard Rating Conditions. Rating Conditions used as the basis of comparison for performance characteristics. 3.13 “Shall“ or “Should.“ “Shall“ or “should“ shall be interpreted as follows: 3.13.1 Shall. Where “shall“ or “shall not“ is used for a provision, that provision is mandat
22、ory if compliance with the standard is claimed. 3.13.2 Should. “Should“ is used to indicate provisions which are not mandatory but are desirable as good practice. 3.14 Short Circuit Ratio (RSCE). The short-circuit power at the point of common coupling (PCC), divided by the rated apparent power of th
23、e drive and as defined in IEC Standard 61000-3-12, Section 3.14 Subsection C. 3.15 Supply Voltage (Vs). The line to line input voltage to the equipment at time of testing. 3.16 System Loss. The combination of electrical and mechanical losses represented by the difference between input power to the d
24、rive and output power from the motor. 3.17 Total Harmonic Distortion. A measure of power line distortion that sums the contributions of the individual harmonics. VFDs typically only contribute odd numbered harmonics with a decreasing impact of the higher order harmonics. 3.18 Variable Frequency Driv
25、e (VFD). A power electronic device that regulates the speed of an alternating current (AC) motor by adjusting the frequency and the voltage of the electrical power supplied to the motor. 3.19 Variable Torque (VT). Applications where the torque requirement of the driven load is reduced as speed is re
26、duced. Centrifugal fans and pumps are examples of variable-torque (VT) loads. 3.20 Voltage Class. The range of utilitization voltages that categorize equipment. 3.21 Voltage Rise Time (dv/dt). The time required for the voltage to increase, measured at the motor terminals when operated from a VFD, fr
27、om 10% to 90% of the VFD steady state DC bus voltage. Section 4. Classifications 4.1 Classifications. VFDs falling within the scope of this standard based on Voltage Class specified in Table 1A. shall be classified as shown in Table 1B.: AHRI STANDARD 1211 (SI)-2011 3 Table 1A. Voltage Classes VFD V
28、oltage Rating (V) Voltage Class (V) 200 to 240 208 440 to 480 460 550 to 600 575 Table 1B. Power Classifications Size Classification Power (kW) 208 V 460 V 575 V Small 0.75 0.75 0.75 1.50 1.50 1.50 2.25 2.25 2.25 3.75 3.75 3.75 Medium 5.60 5.60 5.60 7.45 7.45 7.45 11.20 11.20 11.20 14.90 14.90 14.90
29、 18.65 18.65 18.65 Large - 22.35 22.35 - 29.80 29.80 - 37.30 37.30 - 44.75 44.75 - - 55.90 Note: Nominal kilowatt ranges are determined for applied motors that fall within NEC current ratings table. Section 5. General Test Requirements 5.1 Test Requirements. VFDs shall be tested in accordance with t
30、he procedures set forth in Appendix C of this standard. 5.1.1 Electrical Conditions. Tests shall be performed at the voltages listed above in Tables 1A and 1B per the rated Voltage Class and frequency of the motor drive systems unless otherwise specified in this standard. Note: Since motor drive sys
31、tems with a 230 V rating are commonly operated at a utilization voltage of 208 V, then all 230 V rated motors shall be tested at 208 V Class. 5.1.2 Power Source Requirements. The power source shall meet the following requirements while measurements are being taken during testing: 5.1.2.1 The power s
32、ource voltage and frequency at the VFD input terminals shall be maintained during the test at the rated voltage of the motor (e.g. 208, 460, 575 V) and rated frequency with a tolerance of 0.5%. 5.1.2.2 The power source-voltage unbalance during the test shall not exceed 0.5%. Phase-voltage unbalance
33、shall be determined as defined in IEEE Standard 141. 5.1.2.3 The source impedance of the power supply shall not exceed 1%. AHRI STANDARD 1211 (SI)-2011 4 5.1.3 Test Motor Selection. The motor selected for testing shall be a NEMA design B four-pole complying with NEMA MG-1 Part 31. Where the motor fu
34、ll-load amp (FLA) rating does not exactly match the rated VFD output amps, select the next smaller motor in the same Voltage Class. A table identifying motor manufacturer and model number for each size and voltage shall be included in the standard after a test laboratory has been identified. 5.1.4 S
35、peed/Load Testing Points. Table 2 shows the various speed/load combinations where measurements are taken for Drive System Efficiency and Motor Insulation Stress. Table 3 shows the various speed/torque test points where measurements are taken for the Power Line Harmonics. Details of the procedure for
36、 each test are presented in Appendix C. Table 2. Speed/Torque Test Points for Drive System Efficiency and Motor Stress Insulation Tests Percent Torque 16% 25% 56% 100% Percent Speed 40% VT CT 50% VT CT 75% VT CT 100% CT/VT Notes: 1. Output frequency or other readouts from the VFD shall not be used t
37、o determine percent speed. 2. Only those cells that contain CT or VT are test points Table 3. Speed/Torque Test Points for Powerline Harmonics Test Percent Torque 16% 56% 100% Percent Speed 40% CT 50% VT CT 75% VT CT 100% CT/VT Notes: 1. Output frequency or other readouts from the VFD shall not be u
38、sed to determine percent speed. 2. Only those cells that contain CT or VT are test points 5.1.5 Drive Settings. The VFD shall be set-up according to the manufacturers instructional and operational manual included with the product. Manufacturers shall also provide parameter set-up summary including a
39、t minimum: 5.1.5.1 Carrier switching frequency, Hz 5.1.5.2 Max frequency, Hz 5.1.5.3 Max output voltage, V 5.1.5.4 Motor control method (i.e. V/f ratio, sensor less vector, etc.) AHRI STANDARD 1211 (SI)-2011 5 5.1.5.5 Load profile setting (constant torque, variable torque, etc.) 5.1.5.6 Saving energ
40、y mode (if used) Note: One summary sheet shall be supplied for constant torque and a separate one for variable torque testing. Deviation from the resulting settings, such as Carrier Switching Frequency or load torque curves, for the purpose of optimizing test results shall not be permitted. For exam
41、ple, parameters dealing with carrier frequency shall be unchanged from one test to the other. 5.1.6 Motor Wires. The three load current carrying conductors between the VFD and motor shall be part of a shielded cable intended for VFD/motor applications. This cable shall be a symmetrical type having c
42、opper conductors, type XHHW with 2 spiral insulations on the current carrying conductors, three smaller ground wires and an overall jacket made of type XLPE insulation. The cable shall be sized per Table 4. Where the cable is not available with the current carrying conductors in the size shown in Ta
43、ble 4, the next larger size shall be used. Table 4. VFD to Motor Conductor Sizes 208 V 460 V 575 V Power (kW) Wire Gage (AWG) Diameter (mm) Wire Gage (AWG) Diameter (mm) Wire Gage (AWG) Diameter (mm) 1.0 14 1.63 14 1.63 14 1.63 2.0 14 1.63 14 1.63 14 1.63 3.0 14 1.63 14 1.63 14 1.63 5.0 12 2.05 14 1
44、.63 14 1.63 7.5 10 2.59 14 1.63 14 1.63 10.0 8 3.26 14 1.63 14 1.63 15.0 6 4.11 10 2.59 12 2.05 20.0 4 5.19 8 3.26 10 2.59 25.0 3 5.83 8 3.26 8 3.26 30.0 2 6.54 6 4.11 8 3.26 40.0 - - 4 5.19 6 4.11 50.0 - - 3 5.83 4 5.19 60.0 - - 2 6.54 3 5.83 75.0 - - - - 2 6.54 5.1.7 Motor Thermal Equilibrium. App
45、ly the rated voltage and frequency to the drive and full load torque to the motor until thermal equilibrium is reached. Individual test steps in Appendix C. shall indicate whether they are to be conducted at this thermal stabilization temperature. 5.1.8 Ambient Temperatures. The ambient temperature
46、at the VFD vicinity (approximately 1 meter away and not in the exhaust air stream of the VFD) during testing shall be maintained within the range of 21C - 27C. 5.1.9 Reference Equations. 5.1.9.1 The Total Harmonic Distortion (THD) shall be calculated as follows: AHRI STANDARD 1211 (SI)-2011 6 =40221
47、THDnXnX1 Where: Xn= current or voltage, A or V 5.1.9.2 The output power shall be calculated as follows: K(kW)power Output ST= 2 Where: S = Speed, rpm T = Torque, Nm K1= 9549 5.1.9.3 The Drive System Efficiency shall be calculated as follows: 100%(kW)Power Input (kW)Power Output (%) Efficiency System
48、 Drive = 3 5.1.9.4 The % impedance shall be calculated as follows: % 100Impedance % =sourceVFDIsccIrated4 Where: IratedVFD= VFD rated current, A Isccsource= Source short circuit current, A Section 6. Rating Requirements 6.1 Published Ratings. Published Ratings shall include Drive System Efficiency,
49、Motor Insulation Stress, and Power Line Harmonics. 6.1.1 Drive System Efficiency shall be expressed in terms of % and stated to the nearest 0.5 %. 6.1.2 Motor Insulation Stress shall be expressed in terms of peak voltage and rise time stated to the nearest 10 Vrmsand 0.01 sec, respectively. 6.1.3 Power Line Harmonic currents shall include the following parameters as shown below in Table 5, expressed in terms of % and stated to the nearest 1%. AHRI STANDARD 1211 (SI)-2011 7 Table 5. Reported Harmonic Current Size (kW) Reported RSCEReported
