数字控制延时对并网变流器控制性能的影响及基于DSP的优化设计

Influence of Delay on Performance of Grid-connected Converter and its Optimization Based on DSP

数字控制系统不可避免的存在延时,而延时环节会影响系统的稳定性。文中以单电感滤波的二极管钳位三电平并网变流器为例,分析几种典型软件架构下的延时区别及对控制性能的影响,得出控制延时越小越有利于改善系统稳定性和提高并网波形质量的结论。提出了一种工程上基于DSP的缩短控制延时的方法,在一台并网变流器上进行试验,试验结果验证了方法的有效性,具有工程应用价值。

The digital control system inevitably has delay,and the delay link will affect the stability of the system.Taking the diode clamped three-level grid connected converter with single inductor filter as an example,this paper analyzes the delay difference and its influence on the control performance under several typical software architectures,draws the conclusion that the smaller the control delay is,the better the stability of the system and the quality of the grid connected waveform will be.In this paper,a method of shortening control delay based on DSP is proposed,which is tested on a grid connected converter.The test results verify the effectiveness of the method and have engineering application value.