电机驱动用新型谐振直流环节电压源逆变器

为了实现电机控制系统的高功率密度和高性能运行，必须提高逆变器的工作频率以提高功率变换器的效率和增强性能。然而，较高的工作频率会引起严重的电磁干扰和开关损耗从而导致系统整体效率降低。软开关技术被认为是解决上述问题的有效方法，结合软开关技术的优点和脉宽调制(pulse width modulation, PWM)控制的特点，提出了一种新的用于电机驱动系统的谐振直流环节软开关电压源逆变器，通过在传统硬开关逆变器的直流环节添加辅助谐振单元，实现了逆变桥开关器件的PWM软开关动作，同时，辅助谐振单元的开关也为软开关操作。文中阐述了该软开关逆变器拓扑的动作时序和动作模式，并对软开关动作时序的瞬态过渡过程进行了数学分析。对提出的新型软开关逆变器驱动无刷直流电机进行了仿真和实验研究，结果验证了电路结构和理论分析的正确性与可行性。

A Novel Resonant DC Link Voltage Source Inverter for Motor Drives

To achieve high performance and the high power density in motor control system, the higher switching frequency of inverter is required to increase the efficiency and performance of converter. However, higher switching frequency may cause higher switching losses, higher electro-magnetic interference (EMI) and lower overall efficiency. The use of soft-switching techniques in inverter can resolve these problems. A novel parallel resonant DC link (PRDCL) voltage source inverter (VSI) is proposed for motor drives, which has advantages of soft-switching inverter and pulse width modulation (PWM). Realize soft switching operation of all switching devices in inverter by adding auxiliary resonant unit to DC link of conventional one. Auxiliary switches are also operated under zero current switching (ZCS) or zero voltage switching (ZVS). Resonant time is short and resonance only uses an inductor, so resonant unit consumes little power. The position and width of zero voltage transition can be freely selected, and resonance is carried on without threshold restriction. Simulation and subsequent experiment are performed for brushless DC motor (BLDCM), and their results confirm validity of soft switching inverter presented.