New energy vehicle testing
Release time: 22-11-11 16:53 Number of views: ninety-four
With the development of new energy vehicles and the troubles of the current number limit policy, many people will start to consider new energy vehicles when buying cars. The main consideration is the charging and endurance of new energy vehicles. How to test electric vehicles?
DEWETRON Test verification of equipment used in new national standard of power battery
The charging and discharging test of electric vehicles mainly refers to GB/T31486, which is divided into two parts: single battery and battery module. The test includes rated capacity, rated energy, initial capacity, capacity recovery ability, high and low temperature test, etc. The new national standard Safety Requirements for Traction Batteries for Electric Vehicles is expected to be implemented in August this year, which includes the escape time of electric vehicles that consumers care about, and the DEWETRON equipment is used for the early test verification of the new national standard.
Figure 1 Electric Vehicle Charging and Discharging Test
DEWETRON products are widely used to test NEDC, WLTP and EPA under three working conditions
In general endurance test, there are three endurance standards: NEDC, WLTP and EPA. The results of NEDC bench test are often far from those collected under actual driving conditions. This problem is also common in other driving cycle tests, such as 10-15 mode in Japan or FTP72 and FTP75 in the United States. In contrast, WLTP standard (World Light Vehicle Test Procedure) is a more realistic working condition, which is used to evaluate traditional vehicles and future electric vehicles, such as hybrid electric vehicles, BEVs (battery electric vehicles), PHEVs (plug-in hybrid electric vehicles) and FCEVs (fuel cell electric vehicles). WLTP is more dynamic, and its results match the road performance. EPA is the American standard. DEWETRON products are widely used in these three conditions.
Fig. 2 Four motor test
DEWETRON has been used for the evaluation of Xuanyuan Award for four consecutive years
In the past four years, as a professional manufacturer of electric vehicle testing equipment, Dewei has been selected as a partner by EFS and added to the evaluation of the Xuanyuan Award. We are responsible for the evaluation of energy consumption and endurance of electric vehicles. The evaluation is carried out according to the WLTP standard and is divided into two parts: bench test and road test.
Figure 3 WLTP Bench Test
Zero Cross algorithm and adaptive anti aliasing filter ——Key to power measurement accuracy
In the process of new energy vehicle testing, the inverter and motor are two important test components. The key to ensure the power measurement accuracy is accurate frequency identification and filter time correction. At present, the power parameters in all software are calculated based on the data of the previous cycle. In this case, the manually selected filter cannot guarantee the accuracy of frequency measurement during the dynamic change of frequency. In addition, the synchronous acquisition of mechanical parameters such as speed and torque requires that the test equipment must be able to automatically adjust and compensate according to the filtering delay. DEWETRON's Zero Cross algorithm and adaptive anti aliasing filter can well ensure the accuracy of the system.
Figure 4 Electric Vehicle Test Points
Power module - variable frequency motor test
Motor control is completed by frequency converter, whose switching frequency directly determines the motor's vibration, noise and other parameters, while some frequency converters can have switching frequency as high as 100KHz. In order to restore the actual waveform at the moment of PWM signal switching, the test equipment has higher sampling rate 。 DEWETRON has specially designed a power module with 2MHz and 10MHz sampling rate per channel for this purpose, which can locate the waveform of each PWM signal.
Figure 5 Analysis and Comparison of PWM Signals at High and Low Sampling Rates
Birds eye function - real-time synchronous acquisition and display of vehicle position and other acquisition parameters
The Birds eye function is a synchronous GPS map positioning display function specially designed by DEWETRON for vehicle testing. It can synchronously display the vehicle position information in the map. With the power parameters and video signals synchronously collected, the tester can visually view the corresponding vehicle position and surrounding environment information when the vehicle parameters change.
Channel dragging completes power group setting
In order to simplify the preparatory work for the test, we designed the touch drag operation mode to simplify the channel configuration. The tester selects different wiring modes, and then completes the power group setting through simple channel drag.
Figure 7 OXYGEN Parameter setting interface
With the development of new energy vehicles, new energy vehicles increasingly need more professional testing equipment. Based on the experience accumulated in the field of vehicle testing for 30 years, DEWETRON has also launched more new products for new energy vehicle testing: energy flow testing system, energy recovery testing system, energy consumption testing, ECU and motor efficiency testing, charging pile testing system Wireless charging test system, We are ready to meet various challenges.
