Motor Summit Zurich Switzerland October 12th, 2016

Pierre Angers, Lab Manager Hydro-Quebec Research Institute

VARIABLE FREQUENCY DRIVE TESTING STANDARDS REVIEW

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Context

• Many Drive Technologies Available Today in Range of Several hp (kW) up to 100 hp (75 kW) and more

• Claimed Efficiency - IE4 (IE5?) • Variable Speed and Torque Capability • Need for Global Testing Standard • Few Independent Lab Evaluations

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VFD Standards

• Canadian Standards Association: CSA C838-2013

• Air Conditioning, Heating and Refrigeration Institute: AHRI 1210-2011

• CENELEC: EN 50598-2 • IEC 61800-9-2 (FDIS)

• IEC TS 60034-2-3 (for Motors fed by VFD)

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Types of Method

• CSA 838 • Input-Output

• AHRI 1210 • Input-Output

• IEC 61800-9-2 (EN 50598) • Input-Output • Calorimetric • Calculations

• IEC TS 60034-2-3 (for Motors fed by VFD) • Input-Output • Calculations

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Specifications in Standards

• Type of Methods • Instrumentation Requirements • Uncertainty • Specific Points in Load Test

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Comparison of Methods

• Input-Output

• Calculations

• Calorimetric

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Input-Output

1 2

3

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Input-Output

• CDM Input

Typical Waveform at the CDM Input (One phase)

Voltage

Current

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Input-Output

Cumulative Real Power due to Harmonics

Power Spectrum at the CDM Input 0

20

40

60

80

100

120

0.1

1

10

100

1000

10000

100000

0 60 120 180 240 300 360 420 480 540 600 660 720 780 840 900 960

Cum

ulat

ive

Pow

er (W

)

Pow

er (W

)

Frequency (Hz)

Real Power

Cumulative Real Power dueto Harmonics

37 kW at 100 % Speed and 50 % Torque

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Input-Output

CDM Output

Typical waveforms at the output of CDM (One phase)

Voltage

Current

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Input-Output

Cumulative Real Power due to Harmonics

Power Spectrum at the Output of CDM 0

40

80

120

160

200

240

0.1

1

10

100

1000

10000

100000

0 4000 8000 12000 16000 20000 24000 28000

Cum

ulat

ive

Pow

er (W

)

Pow

er (W

)

Frequency (Hz)

Real Power

Cumulative Real Power dueto Harmonics

37 kW at 100 % Speed and 50 % Torque

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Input-Output

Total Accuracy in Power Measurement

Specifications Computation *Accuracy Based on Frequency, Range and PF

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Input-Output • CDM input • 60 Hz Base accuracy = ± 0.09 % • 66 Hz < f ≤ 1 kHz: ± 0.14 % * 0.4% = ± 0.0006 % • Total Accuracy = √ (0.092 + 0.00062) = ± 0.09 % • Accuracy at CDM input = ± 0.09 % • CDM Output • 60 Hz Base accuracy = ± 0.09 % • 66 Hz < f ≤ 1 kHz: ± 0.14 % * 0.1% = ± 0.00014 % • 1 kHz < f ≤ 10 kHz: ± 0.31 % * 0.6% = ± 0.00185 % • 10 kHz < f ≤ 50 kHz: ± 0.62 % * 0.2% = ± 0.00130 % • Total Accuracy = √ (0.092 + 0.0001422 + 0.001852 + 0.001302) • Accuracy at CDM output = ± 0.09 % • Total Accuracy = √ (0.092 + 0.092) = ± 0.13 %

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Calculations Method

• Method Proposed in IEC 61800-9-2

• Tables, Formulas and Calculations Based on CDM's

Manufacturers Data

• Convenient for Manufacturers

• Limited Application for Testing Labs

• Method Claimed Uncertainty of 10 % on CDM Losses

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Calorimetric Method

• Only Proposed in IEC 61800-9-2 • Specified For CDM Only

• Method Claimed Uncertainty of ± 5 % on the Measured Losses

• Method Difficult to Implement Requiring Test Chamber

• Most Motor / Drive Test Facilities Based on Dynamometers (Input-Output)

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Losses vs Uncertainty with Different Methods (Motor)

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Losses vs Uncertainty with Different Methods (CDM)

**These values are given as references only and have not

been validated yet.

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Losses vs Uncertainty with Different Methods (PDS)

**These values are given as references only and have not

been validated yet.

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Conclusion

• Different Methods Proposed • One common Method Included in All Standards:

Input-Output • This Method is Usable for All (Manufacturers

and Independent Test Labs) • Seems to Make Consensus • If Instrumentation Used has Low Uncertainty →

Determination of Losses (or Efficiency) can also be made with Low Uncertainty

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Thank you!

Pierre Angers, P. Eng. Hydro-Québec's Research Institute Shawinigan, Quebec, Canada angers.pierre@ireq.ca