What is the principle of chopper control for mining motor vehicles?

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Excuse me, who knows the specific situation of chopper control on the mining motor car?

At present, most of the mining motor vehicles use string resistance speed regulation. Although this method is relatively mature, there is a large amount of energy consumption in the resistance, which causes great waste of energy. This paper studies a speed regulation based on DC chopping. The method section adopts a full-control type switching device, and has the advantages of a system frequency bandwidth, a fast response speed, and a strong dynamic anti-interference capability. The hardware part of the DC chopper speed controller of the mine electric vehicle is mainly divided into two parts: the main circuit and the control circuit. Firstly, the main circuit is designed, and then the chopper power switch IGBT is selected. Finally, the control circuit is designed. The control circuit is based on ATmega16 MCU. The control circuit includes power supply circuit, sampling circuit, speed control circuit, M57962L drive circuit, undervoltage protection circuit, overcurrent protection circuit and reset circuit. Alarm circuit and expansion circuit.

The working principle of the control circuit: Firstly, under the stable supply of the power supply, the Atmega16 MCU works stably. When the speed is adjusted, the PWM waveform is changed according to the change of the input quantity, and then the signal is amplified by the power drive module M57962L of the IGBT, and finally sent. The switching element IGBT is used to realize the chopper speed regulation. During the speed regulation process, the MCU samples the main circuit current and the power supply voltage at the moment, such as overcurrent protection for overcurrent, and undervoltage protection for undervoltage. In the startup phase, in order to prevent voltage surge and impact on the motor, a set of soft start program is designed by scanning gear position method, which has good practical value and application prospect. Finally, the stability and reliability of the DC chopper speed controller are verified by a large number of experiments. The experimental results show that the system is stable and reliable, and the performance meets the expected design requirements.