电力电子变压器输出侧频率无差控制

Frequency-free Control of Power Electronic Transformer Output Side

针对孤岛运行的微电网,实现系统频率的恢复和功率在电力电子变压器(PET)输出侧逆变器间的合理分配需要依赖于通信系统。基于此,提出了一种无需通信的频率恢复和功率分配策略。该策略通过在PET输出侧逆变器控制环中引入频率偏差补偿环节,使得PET输出侧各逆变器仅仅依靠本地信息即可实现频率的快速恢复。同时,所提策略还能实现负荷扰动功率在PET输出侧各逆变器间按容量分配,有利于微电网经济运行。最后搭建了实验样机验证了所提策略的可行性。

For island-running microgrids,the restoration of system frequency and the rational distribution of power between inverters on the output side of a power electronic transformer(PET) need to rely on the communication system.Based on this,a communication-free frequency recovery and power allocation strategy is proposed.In this strategy,the frequency deviation compensation link is introduced into the control loop of the inverter at the output side of the PET,so that the inverters at the output side of the PET can achieve rapid frequency recovery only by relying on local information.At the same time,the proposed strategy can also realize the distribution of load disturbance power among the inverters on the output side of the PET according to the capacity,which is beneficial to the economical operation of the microgrid.Finally,an experimental prototype is built to verify the feasibility of the proposed strategy.