一种三相软开关PWM变流器电流极性检测与电流补偿方法  

A CURRENT POLARITY DETECTION AND CURRENT COMPENSATION STRATEGY FOR A THREE-PHASE SOFT-SWITCHING PWM CONVERTER

作　　者：屈克庆[1] 陈国呈[1] 孙承波[1] 许春雨[1] 

机构地区：[1]上海大学自动化系,上海市闸北区200072

出　　处：《中国电机工程学报》2005年第15期46-50,共5页Proceedings of the CSEE

基　　金：国家自然科学基金项目(59977012)。~~

摘　　要：对于一种基于幅相控制的三相零电压开关PWM变流器,在利用正负斜率交替的锯齿载波调制方式下,需要按照电流极性来进行锯齿载波斜率的交替翻转,由于在翻转处会造成电流畸变,也需要按照电流极性变化的时刻来补偿。该文从单位功率因数变流器的固有特点出发,在顺变和逆变状态下,提出了电流极性检测的软件实现方法,分析了使用正负斜率锯齿载波带来的电流过零点失真的原因,并给出了相应的补偿方案。该方法有效保证了软开关技术在三相PWM变流器上的实现,具有简便有效、节约硬件资源、相电流谐波较小等优点。For a phase and amplitude control （PAC） based three-phase zero-voltage soft-switching （ZVS） PWM converter, when saw-tooth carriers with alternative positive and negative slopes are used in PWM, it must be according to the phase current polarity to choose either positive or negative slope for the saw-tooth cartier, moreover, owing to the reversal of positive or negative slope for the saw-tooth cartier bring current distortion, it should compensate for current at the time for the reversal of current polarity. Based on the characteristic of unity power factor converter, in rectifying and regenerating modes, a software realization method for current polarity detection is proposed, the distortion of current zero-cross caused by adopting saw-tooth carriers with alternative positive and negative slopes is analyzed and its relevant compensation method is given. The proposed strategy is effectiveness and hardware-saving for the implementation of ZVS technique in converter, the phase current has a small harmonic content and near-sinusoidal waveform, these are demonstrated by experiment results.

关 键 词：电流极性检测 电流补偿 变流器 零电压开关 幅相控制 

分 类 号：TM46[电气工程—电器]