How to connect the inverter braking unit
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I would like to ask the experts for their advice: I have a 250KW inverter used to drive a 232KW three-phase AC motor fan. During the shutdown process of the inverter, its modules sometimes get damaged (this inverter does not have a braking unit). I believe that the reason for this is the absence of a braking unit; due to the high inertia of the fan, a large amount of energy is reflected back to the inverter, which causes its modules to be damaged. Is my view correct? Additionally, I would appreciate it if the experts could provide me with examples of diagrams showing how an inverter is connected to a braking unit. Thank you!
Your view is correct. In the absence of a braking unit, especially for high-power and high-inertia loads such as fans, when the frequency converter is turned off, the regenerative energy generated by the motor is not effectively dissipated, which can easily lead to overvoltage faults in the inverter module. To solve this problem, an external braking unit and braking resistors can be installed. The working principle of the braking unit is to convert excess energy into heat energy through braking resistors when the motor slows down, thereby protecting the inverter from being damaged by the regenerative energy. The specific connection method is as follows: 1. First, confirm whether your inverter model is compatible with the brake unit model. 2. Connect the input terminals of the braking unit to the DC+ (positive DC) and DC- (negative DC) of the inverter. 3. Connect the braking resistor to the output terminal of the braking unit. 4. Ensure that all connections meet electrical safety standards and that necessary insulation is applied. It is best to refer to the specific instructions for the inverter and braking unit when making the connections, as the connection methods may vary depending on the model and brand of the equipment. If you are not sure how to connect it safely, it is recommended to consult a professional electrical engineer or the manufacturer’s technical support. .
Thank you very much for your guidance. I was wondering if you have any examples or drawings showing how an inverter is connected to a braking unit; if so, please share them!