GB/T 25123.3-2011Electric traction -- Rotating electrical machines for rail and road vehicles -- Part 3: Determination of the total losses of convertor-fed alternating current motors by summation of the component losses (English PDF)

Foreword

GB/T 25123 "Electric traction - Rotating electrical machines for rail and road vehicles"

consists of the following parts:

- Part 1: Machines others than electronic convertor-fed alternating current motors;

- Part 2: Electronic convertor-fed alternating current motors;

- Part 3: Determination of the total losses of convertor-fed alternating current motors

by summation of the component losses.

This Part is Part 3 of GB/T 25123.

This Part was drafted in accordance with the rules given in GB/T 1.1-2009.

This Part uses redrafting method to modify and adopt IEC 60349-3:1995 "Electric

traction - Rotating electrical machines for rail and road vehicles - Part 3: Determination

of the total losses of convertor-fed alternating current motors by summation of the

component losses".

This Part made the following editorial changes:

- According to the requirements of GB/T 1.1-2009, the formula numbers (1)~(8) of

IEC 60349-3:1995 are numbered as (A.1)~(A.9) in this Part. Add numbers to the

formulas in 3.2.1.2 and Annex B;

- Correct the following errors in Table A.2 of the original text:

a) In the formula of item 15, "(1)/(7)" in the original text is changed to "1/(7)";

b) In the formula of item 19, "(17)-(18)" in the original text is changed to

"(17)+(18)";

c) In the formula of item 24, "(23)/(2)" in the original text is changed to "(23)+(2)";

d) In the formula of item 27, "(22)2" in the original text is changed to "(22)".

This Part was proposed by Ministry of Railways of the People's Republic of China.

This Part shall be under the jurisdiction of National Technical Committee on Traction

Electrical Equipment and Systems of Standardization Administration of China

(SAC/TC 278).

Main drafting organizations of this Part: Zhuzhou CSR Times Electric Co., Ltd.

The drafting organizations of this Part: CSR Zhuzhou Electric Co., Ltd. and Yongji

Xinshisu Electric Co., Ltd.

Electric traction - Rotating electrical machines for rail and

road vehicles - Part 3: Determination of the total losses of

convertor-fed alternating current motors by summation of

the component losses

1 Scope

This Part of GB/T 25123 applies to machines that comply with GB/T 25123.2.

The total losses of a convertor-fed motor may be determined by summation of the

component losses derived from no-load and load tests. The total input power is the sum

of the power at the fundamental frequency and at all other frequencies. In all practical

cases the latter input includes the losses resulting from the voltage and current

harmonics in the convertor supply by using suitable instrumentation it can be derived

from measurement of the total and fundamental frequency power inputs when the

machine is on load.

The losses supplied at the fundamental frequency cannot be measured directly and so

are derived from measurement of the fundamental frequency load current and the

fundamental frequency no-load power input.

2 Instrumentation

The extra loss due to operation on a convertor supply is obtained from the difference of

the total and fundamental frequency power input on load.

The power inputs shall be measured simultaneously on each phase by a digital sampling

instrument. Measurement on all three phases is preferred but the two wattmeter method

is permissible as an alternative.

The total power is obtained from the product of voltage and current over a period of

time and the fundamental power from a Fourier transform using the same sampling.

It is necessary to consider the accuracy of the whole instrument chain considering both

amplification and phase shift errors over the desired frequency range. As the power

factor of the harmonics is generally very low (less than 0.l for voltage imposed

asynchronous systems) particular attention is drawn to the need for minimum phase

angle errors.

fully established by experience. Additional information may be obtained by carrying out a low

power test described in Annex B.