Reliability test methods of drive motor system for electric vehicles
1 Scope
This document specifies the test conditions, test procedures, test methods, inspection and maintenance, test result collation, reliability assessment and test report for the bench reliability test of drive motor system for electric vehicles.
This document applies to the drive motor system for electric vehicles, and reference may be made to it for motor system for vehicles with only auxiliary drive function or power generation function.
2 Normative references
The following documents contain provisions which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 2900.13 Electrotechnical terminology - Dependability and quality of service
GB/T 18488.1 Drive motor system for electric vehicles - Part 1: Specification
GB/T 18488.2 Drive motor system for electric vehicles - Part 2: Test methods
GB/T 19596 Terminology of electric vehicles
QC/T 893 Failure classification and assessment of electrical machine system for electric vehicle
QC/T 1022-2015 Technical specification for reduction gearbox of battery electric passenger cars
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 2900.13, GB/T 18488.1, GB/T 19596 and QC/T 893 as well as the following apply.
3.1
rated voltage
nominal voltage of the DC bus as stated by the manufacturer
3.2
continuous torque
maximum mechanical torque at which the drive motor system can operate continuously for a long period of time under the conditions specified by the manufacturer
3.3
rated speed
maximum speed at which the drive motor system can deliver continuous torque under the conditions specified by the manufacturer
4 Test conditions
4.1 General requirements
4.1.1 The devices under test shall be drive motor systems that conform to the requirements of the product technical documents.
4.1.2 Unless otherwise specified, the test conditions shall meet the test preparation requirements in GB/T 18488.2.
4.2 Cooling
During the test, the cooling equipment or cooling conditions shall meet the following requirements.
——For air-cooled drive motor systems, the air-cooled motor actually installed shall present during the test;
——For naturally cooled drive motor systems, additional fans can be used to cool the drive motor system;
——For liquid-cooled or oil-cooled drive motor systems, the coolant or lubricant specified by the manufacturer shall be used, which shall be replaced periodically as prescribed by the manufacturer during the test;
——The cooling conditions of the drive motor system should simulate the actual conditions in the vehicle, and the model of the cooling device for drive motor system, as well as the type of coolant, flow rate (or pressure) and temperature shall be recorded in the test report.
5 Test procedure
5.1 Preparation before test
5.1.1 The connection line between the controller and the motor should be consistent with that used in the vehicle, and the monitoring system shall be installed as well. To ensure that the system can operate properly, the necessary correlation signals shall be simulated or otherwise shielded by other methods.
5.1.2 The power supply, test stand and monitoring system shall be in normal working condition.
5.1.3 If the drive motor system under test contains a reducer, running-in shall be performed in accordance with the requirements in 6.2.3 of QC/T 1022-2015 or as specified by the manufacturer before the test, and then the oil shall be replaced.
5.1.4 If the drive motor system under test contains a reducer, the setting of conditions for the initial performance test, performance retest and reliability test shall be converted based on the reduction ratio of the reducer.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Test conditions
4.1 General requirements
4.2 Cooling
5 Test procedure
5.1 Preparation before test
5.2 Initial performance test
5.3 Reliability test
5.4 Performance retest
6 Test methods
6.1 Test pieces
6.2 Speed lift-down cycle
6.3 Torque load cycle
7 Inspection and maintenance
7.1 General requirements
7.2 Inspection at any time
7.3 Inspections made every 1 h
7.4 Inspections made every 24 h
7.5 Troubleshooting and shutdown handling
8 Test result processing
9 Reliability assessment
10 Test report
Annex A (Informative) Principles for recommended number of cycles in the reliability test
Bibliography
