Study On Double-loop Control In High-power Three-phase And Parallel Operation Of Many Sets

The inverters are widely used in people’s life and work. With the continuous development of social progress, the require of power supplies’ quality is higher and higher. To ensure that the power supplied by inverters is of high quality, stable and easy to adjust is the basic demand of modern electric equipments, and also is the performance index that many power suppliers are chasing. Single inverter can’t satisfy the high power density people need, so the inverter parallel technology is more and more popular nowadays. The researchers take is as a kind of technology that can achieve high power, high reliability. This paper mainly researches inverter waveform control and parallel operation performance, and verifies the feasibility of this subject by single inverter experiment and two parallel inverters experiment.This paper first introduces the inverter waveform control and the method of parallel control strategy, and compares the advantages and disadvantages of various control means through the qualitative analysis. Then this paper proposes a voltage loop, current inner ring double loop PID control way in view of the high power inverter technology requirements of high performance and verifies this method to the improvement of the inverter output waveform by programming and modeling simulation in MATLAB. This method effectively improves the dynamic performance of the inverter output system and ability to resist load disturbance. This paper also expounds the influence of the double loop control of inverter parallel operation by vector analysis and power analysis. On this basis, this paper selects a parallel control method based on distributed logic control.At the end, through single and parallel operation experiment on the three-phase modular inverter parallel system this paper effectively verifies the hypothesis: double loop control can make the inverter output waveform has better dynamic performance and anti-interference ability, distributed logic control can effectively restrain circulation in parallel system, and the system operate stably.