基于双核MCU并行算法的高频双Buck逆变器

摘要

提出了一种适用于小功率可再生能源的高频双Buck全桥逆变器.采用电压-电流双闭环控制器,开关频率达到400 kHz.电压环采用两极点两零点(2P2Z)控制器产生内环电流参考值,电流环采用三极点三零点(3P3Z)补偿器实现电流参考值的无差跟踪.此外,采用反馈线性化方法简化占空比计算,控制速度得到提高.采用二阶广义积分软件锁相环(SOGI-SPLL)获得相角信息,同步逆变器输出电流与电网电压的相位.得益于双核微控制器单元(MCU)的高速实时控制能力,所有控制策略均采用并行计算结构算法实现.最后,基于1 kW实验样机验证了理论分析的正确性和可行性.%A high frequency dual-Buck full-bridge inverter is proposed,which is suitable for small power renewable energy application.The inverter adopts the voltage-current dual loop controller,making the switch frequency reach to 400 kHz.A voltage loop two-pole two-zero(2P2Z) controller is employed to produce the reference of the inner ring current,while a current loop three-pole three-zero(3P3Z) compensator is applied to track the current reference value in a non-error way.Besides,utilizing the method of feedback linearization can simplify duty cycle calculation and increase the speed of control.Through a second-order generalized integrator software phase lock loop (SOGI-SPLL),the information of phase angle is gained,synchronizing the phase of the output current and grid voltage.A dual-core microcontroller unit (MCU) has high-speed real-time control capability,contributing to the control tactics realization based on a parallel calculation structure algorithm.Finally,a 1 kW prototype is built to verify the accuracy and feasibility of the theoretical analysis.