面向单相微电网的双模式并联逆变器协调控制方法

Coordinated Control Method for Dual-mode Parallel Converters in Single-phase Microgrid

微电网中的接口变流器往往采用电压控制方法或电流控制方法。对于电压控制方法,其优点是可以应用在并网/孤岛两种模式下,然而缺点是功率控制动态响应慢。电流控制方法的优点是动态响应快,但是不能应用在孤岛模式。采用分布式电源通过两个并联逆变器接入电网的结构,与传统方法不同的是,其中一个逆变器采用电压控制,另一个逆变器采用电流控制。这种方式可以同时发挥两种控制方法的优势。与此同时,加入功率耦合环节,提高电压控制逆变器和整个系统的动态特性。单相双逆变器的仿真和实验结果证实了所提出的结构与控制方法的有效性。

In a microgrid, two different control methods are often adopted for interfacing converters, the voltage control and current control method. For the former, it can be used in the connected or islanded mode, but it has slow power control dynamics. In contrast,the current control method has rapid power control dynamic response, but cannot be applied during standalone operation. To cope with these problems, the distributed generator（ DG） is connected to the microgrid with two parallel converters. Different from conventional methods, one converter is controlled to regulate voltage while the other to regulate current. In this way, the advantages of both methods are made use of. At the same time, the application of power coupling loop enhances the dynamic characteristics of voltage-controlled converter and DG system. Simulation and experimental results from a single-phase prototype show the validity of the proposed structure and control strategy.