Traction inverter control system and PWM modulation method

Abstract

The invention provides a traction inverter control system and a PWM modulation method. The system comprises a main circuit, a first processor, a second processor and a third processor. The main circuit comprises an inversion unit, the input end of the inversion unit is connected with a DC bus, and the output end of the inversion unit is connected with a load motor. The first processor is connectedwith the main circuit; the second processor is connected with the first processor and is used for generating an excitation inductance signal, an excitation current signal and a torque current signalof the load motor; the third processor is connected with the second processor and is used for generating a zero-sequence voltage regulation quantity signal, a load motor control voltage signal and a load motor control frequency signal and carrying out PWM modulation calculation to generate a modulation signal; the first processor receives the modulation signal, modulates the modulation signal to generate a switching pulse signal and sends the switching pulse signal to the inversion unit. The modulation method can realize smooth and stable switching among the modulation modes, inhibits startingcurrent impact, and is easy to realize, reliable and stable based on the control system.

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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