基于双三角载波的逆变器控制策略

Inverter Control Strategy Based on Double Triangular Carrier Waves

传统滞环电流控制的开关频谱范围大,开关频率不固定,导致滤波器设计困难,同时不利于模块化设计,因此需对其进行改进。通过分析传统滞环控制的定频原理,计算定频策略的实际环宽,给出了改进后的边界电流值,运用到传统控制策略中,实现开关频率的固定,同时可以很容易地根据环宽和参考电流来判断控制型软开关的条件,减小开关损耗。最后,搭建硬件电路进行实验,控制部分由数字信号处理器(DSP)实现,实验结果验证了该定频策略的可行性。

Traditional hysteresis current control has a large switching frequency spectrum and the switching frequency is not fixed which makes it difficult to design the filter,so it needs to be improved.By analyzing fixed-frequency principle of traditional hysteresis control,the actual loop width of the fixed-frequency strategy is calculated,and the improved boundary current value is given.It is applied to the traditional control strategy to realize the fixed switching frequency and it can easily judge the condition of controlled soft switching based on the loop wide and reference current,so that it can reduce switching loss.Finally,hardware circuit is built for experiment and the control part is realized by digital signal processor(DSP).Experimental results verify the feasibility of the fixed frequency strategy.