GB/T 5321-2005 Calorimetric determination of losses and efficiency of electric motors

This standard is equivalent to IEC 60034-2A "First supplementary calorimetric determination of losses of rotating electrical machines". This standard applies to type tests and inspection tests of large AC motors, but its principles also apply to other motors. Matters not specified in this standard shall comply with GB 755 "Ratings and performance of rotating electrical machines". GB/T 5321-2005 Calorimetric determination of losses and efficiency of electrical machines GB/T5321-2005 Standard download decompression password: www.bzxz.net

ICS 29. 160. 01
National Standard of the People's Republic of China
GB/T 5321—2005/IEC 60034-2A:1974 replaces GB/T 5321...1985
Measurement of loss and efficiency for eiectrical machine by the calorimetric method
(IEC 60034-2A (1974):First supplcmcnt to Publication 60034-2(1972)Rotating electrical machinery—-Part 2:Methods for determining lossesand efficiency of rotating electrical machinery from tests(excluding machines for traction vehicles)-:Measurement of losseshy the calorimetric method GB/T5321-2005/IEC60034-2A1974 This standard is a revision of GB/I53211985 "Determination of losses and efficiency of large AC motors by calorimetry". This standard adopts IEC60034-2A:1974 "The first supplement to rotating motors, Determination of maximum losses by calorimetry", and makes editorial changes to the original standard according to GB/11.1-2000, adding Chapter 2: Normative references. The original Chapter 5 "Temperature rise stability" is supplemented, the original Chapter 2 "Symbols" is deleted, and the measurement error is further clarified. This standard is coordinated with other standards for AC motors. This standard is proposed by the China Electrical Equipment Industry Association. This standard is under the jurisdiction of the Generator Sub-Technical Committee of the National Technical Committee for Standardization of Rotating Electric Machines. Harbin Electric Machine Research Institute is responsible for drafting this standard. The main drafter of this standard is Yang Ming.
This standard is interpreted by Harbin Electric Machine Research Institute. The date of this standard was first formulated in 1985.
GB/T5321—2005/IEC 60034-2A:1974 Thermal method for measuring the loss and efficiency of electric motors
Technical standards adopt IEC60034-2A& Rotating electric machine The first supplementary calorimetric method for measuring the loss, this standard is applicable to the type test and inspection test of large AC motors, but its principles are also applicable to other motors. Matters not specified in this standard shall comply with GB755 "Ratings and performance of rotating electrical machines. 2 Normative references || tt || The clauses in the following documents become clauses of this standard through reference in this standard. For dated references, all amendments (excluding errata) or revisions to them are not applicable to this standard. However, parties to agreements based on this standard are encouraged to study whether the latest versions of these documents can be used. For undated references, the latest versions are applicable to this standard. GB755-2000 Ratings and performance of rotating electrical machines Energy (IDT1EC60034-1:1996). 3 Terminology
Calorimetric method
All kinds of losses generated inside the motor will eventually turn into heat and transfer to the cooling medium, causing the cooling medium temperature to rise. The method of calculating the motor loss by measuring the heat generated by the motor is referred to as calorimetry. 4 Measurement method
4.1 Loss determination
Depending on the conditions, any of the following methods can be used to measure the heat to determine the loss. 4.1.1 Measurement of the flow rate and temperature rise of the cooling medium 4. 1.2 Correction of cooling medium temperature rise
4.2 Efficiency determination
Depending on the conditions, any of the following methods can be used to determine the consumption to determine the efficiency. 4.2.1 Determination of total loss under rated load
4.2.2 Measure various losses separately and then add them up to obtain the total loss 5 Formula for determining loss
5.1 Reference surface
In order to classify the total loss, a reference surface is specified for the motor. This is the reference surface that wraps the motor metal parts in a single body. All losses generated within this surface are released through this surface, see Figure 1) The total motor loss includes:
Reference surface internal loss P
Reference surface external loss P
GB/T 5321--2005/IEC 60034-2A:1974?
() radiates to the wall, convects to the surrounding air
control device surface:
thrust bearing cooler:
reference surface internal losses can be divided into two categories: where:
cooling air:
main cooler;
…transmitted to the foundation
一transmitted to the turbine rotor.
Figure 1 Foundation surface
P. = Pi+ P2
is the loss taken away by the cooling system in the form of heat and can be measured by calorimetry. This is the main part of the internal loss of the reference surface.
is the loss that is not transferred to the cooling medium but is dissipated through the reference surface in the form of conduction, convection, radiation, leakage, etc. It accounts for a small part of the total loss and can be measured by calorimetry or calculated. The external loss P of the reference surface is mainly composed of the following parts: the loss of auxiliary equipment outside the reference surface, a)
the bearing friction loss outside the reference surface: 5.2 Determine the loss of each part of the motor by measuring the flow rate and temperature rise of the cooling medium. After the motor reaches thermal stability, the loss taken away by the cooling medium is: P, --. CQPAt
Where:
Losses carried away by the cooling medium inside the reference surface, kW; specific heat of the cooling medium. ki/(kg·K)
Q. Flow of the cooling medium, ms
β-density of the cooling medium, kg/rn;
At-temperature rise of the cooling medium, K.
If the cooling medium is water, the measurement method is given in Chapter 7. If the cooling medium is air, the measurement method is given in Chapter 8. 5.3 Losses not transferred to the cooling medium
5.3.1 Losses transferred to the motor foundation and shaft due to heat conduction These losses are very small and can be ignored. 5.3.2 In open-ventilated motors, the losses caused by the change of air kinetic energy are very small and can be calculated using the following formula: Where:
P - loss caused by the change of cooling air kinetic energy, kW Q air flow, ml/s: bzxZ.net
p air density, kg/m;
Tr~m~ outlet wind speed, Tn/x.
5.3.3 Losses caused by convection between the outer surface of the motor and the surrounding air to the factory building GB/T 5321—2005/IEC 60034-2A:1974 The amount of radiation loss caused by the motor surface to the factory building is very small and can be ignored. When measuring, only the loss caused by convection between the outer surface of the motor and the surrounding air is considered. The loss calculation formula is: P2-hAAt
Where:
The power dissipated from the outer surface of the motor.k
A——Heat dissipation surface area.m;
The difference between the motor surface temperature and the external environment temperature, K; Af
h——Surface heat dissipation coefficient, W/(m·K), the surface heat dissipation coefficient h, generally has a value range of (10-~20)W/(m2·K). The value of the surface micro-thermal coefficient in contact with the air can be calculated using the following formula: a) For the outer surface:
= 11 —3
h——External surface heat dissipation coefficient, W/
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