在航空航天等特殊应用领域里通常需要电源系统提供高质量、高可靠性的400 Hz中频交流电源输出,而逆变器的并联控制技术可实现冗余供电和大容量供电,是当今逆变电源发展的重要方向之一。首先,对逆变器主从并联系统的整体结构进行分析和设计以实现良好的信号传输和冗余控制;其次,针对单台中频逆变器模块,采用了基本PR控制器的电压电流双闭环控制策略以改善其输出特性;随后,对基于平均功率控制策略的逆变器主从并联系统进行系统分析,并在从机控制系统里引入虚拟阻抗以改善其输出特性;最后,通过仿真和实验验证逆变器并联系统结构和控制策略的可行性。
High quality and high reliability 400 Hz frequency AC power supply is strongly demanded in the field of aerospace, ships, radar, petroleum, metallurgy, communications switches and other power systems. The control technology of Paralleled inverters can make power supply more redundant and higher capacity, which is one of inverter's development trends. In the paper, the overall structure is designed for the Master-slave Paralleled Middle- Frequency Inverters' System to realize a redundant signal transmission and logic control. Voltage and current double closed-loop control strategies based on PR controller is used for a single inverter to improve its output characteristics. The paper establishes the mathematical model of the two paralleled inverters' system and designed a suitable scheme based on the average power control. Virtual impedance is added in the slave module's control loop to improve the output performance. Finally, the validity of the designed system structure and control schemes are verified by the simulation and experiment results.