基于有功和无功环流控制的DC-AC逆变器并联系统分析与实现

传统的基于有功和无功环流控制的逆变器并联控制方法是由电力系统中同步电机并网理论演变而来,即根据输出有功功率差调节输出电压的相位,根据输出无功功率差调节输出电压的幅值,实现输出负载均分.该控制方式若应用于电压电流双闭环控制逆变器并联系统会引起系统工作不稳定,本文分析了造成不稳定的原因,给出了电压电流双闭环控制DC-AC逆变器并联系统输出有功和无功功率差与输出电压幅值、相位差之间的定量关系,提出了相应的均流控制策略,给出了并联系统的实现方案.实验结果验证了该控制方案的可行性.

Analysis and Realization of DC-AC Inverter Parallel System Based on Active and Reactive Circulating-Current Control

Traditional inverter parallel control strategy which adopts active and reactive circulating-current control evolved from the grid-connection theory of synchronous generator in electric power system. In order to realize load-sharing, it regulates the phase of the output voltage according to the output active power difference and regulates the output voltage magnitude according to the output reactive power difference. If this control strategy is applied to the voltage and current double closed-loop controlled inverter parallel system, it will result in the instability of system. This paper analyzes the reason of instability. The quantitative relationship between the output voltage phase, magnitude difference and the output power difference of the voltage and current double closed-loop controlled DC-AC inverter parallel system is given. Corresponding control strategy is proposed and realization scheme of parallel system is given. The experimental results verify the feasibility of the proposed control scheme.