Traction inverter control system and pwm modulation method

Abstract

The present invention proposes a traction inverter control system and a PWM modulation method, the system includes a main circuit, a first processor, a second processor and a third processor; the main circuit includes an inverter unit, and the input end of the main circuit is connected to a DC The bus bar, the output end of the main circuit is connected to the load motor; the first processor is connected to the main circuit; the second processor is connected to the first processor to generate the excitation inductance signal, excitation current signal and torque current signal of the load motor; The third processor is connected with the second processor, and is used to generate zero-sequence voltage adjustment signal, load motor control voltage signal, load motor control frequency signal, and perform PWM modulation calculation to generate modulation signal; the first processor receives modulation The signal is modulated to generate a switching pulse signal and sent to the inverter unit. The modulation method can realize smooth and stable switching among various modulation modes, suppress the impact of starting current, and meanwhile, based on the control system, it is easy to implement, reliable and stable.

Description

technical field [0001] The invention belongs to the field of traction inverters, in particular to a traction inverter control system and a PWM modulation method. Background technique [0002] The three-level traction inverter has the advantages of low switching frequency, low loss, high efficiency, reduced harmonic content, improved output waveform quality, and reduced withstand voltage requirements for switching devices. It has been widely used in high-speed EMUs. And gradually get attention in the application of subway vehicles. [0003] At present, the three-level inverter control system mostly uses dual processors to work together. DSP is responsible for the real-time operation of complex control algorithms as the main processor, and FPGA is responsible for AD sampling control and PWM signal generation as the co-processor, which reduces the burden on DSP. Budget burden, the control system can run complex grid-connected control programs, which improves the real-time perf...

AI Technical Summary

Problems solved by technology

However, the SVPWM modulation method of the traditional three-level inverter is more complicated in the realization of the control method, including the judgment of the reference vector sector and the calculation of the basic vector action time, etc., which involve more trigonometric function operations and table queries. , the modulation algorithm is extremely cumbersome, so it will bring a large burden to the controller, which will lead to problems such as poor control accuracy of the controller hardware, unstable modulation mode switching, and poor output waveform quality, which is not conducive to the development of three-level inverters.

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