The electric vehicle battery test is in the running state, and it is necessary to understand the operation of the accessories, and the drive and other accessories are in operation.
If the electric vehicle battery test is not isolated between the AC power source and the drive DC bus (such as a transformer), do not connect the non-isolated port of the DC bus or the ground of the non-isolated signal to the ground, which may result in equipment damage and personal injury. Because the common voltage of the AC is not earth-proof, there may be a high voltage between the DC bus ground and the earth.
In most electric vehicle battery test systems, all common ground and earth are connected together at the signal end. A variety of ground loops generated by grounding are susceptible to noise and generate flow at different reference points.
In order to keep the command reference voltage constant, the signal ground of the driver is connected to the signal ground of the controller, which is also connected to the ground of the external power supply, which will affect the operation of the controller and the driver.
It is difficult to test the grounding of the shield layer of the electric vehicle battery. There are several methods. The correct shielding grounding is at the reference potential point inside the circuit. This point depends on whether the noise source and the receiving are grounded at the same time, or floating. Make sure that the shield is grounded at the same point so that ground current does not flow through the shield.
For the electric vehicle battery test to maintain a stable operating state, it is necessary to understand the operation of the above accessories.