三相电压型PWM整流器不平衡控制虚拟导纳法

输入电压不平衡会导致三相电压型PWM整流器谐波增加、损耗增大,严重时可以烧坏整流器。针对传统的解决方案结构较复杂、运算量大,提出虚拟导纳控制法。根据三相电压型PWM整流器不平衡时瞬时功率平衡理论,找到虚拟导纳这一核心控制量,引入可实现电流无静差控制的广义积分器,形成两相静止坐标系下电流控制简化方法,由此设计了虚拟导纳控制系统。通过Matlab仿真和实验验证表明该控制方法不仅性能稳定,实现三相电压不平衡时电压无波纹控制和实时可控的功率因数,而且不需要对正负序电流进行独立检测,提高了系统的快速性。引入的广义积分器具有的简单离散迭代算法也大幅减少了计算量。

Virtual admittance control scheme of three-phase PWM rectifier under unbalanced input voltage condition

Unbalanced input voltage leads to the increase of harmonic and loss in three-phase PWM rectifier. As the traditional solutions to it have relatively complex structure and large calculation load,a simplified current control under two-phase stationary frame is proposed,which takes the virtual admittance as the key control variable based on the balanced instantaneous power theory of three-phase PWM rectifier under unbalanced input voltage conditions ,and applies the generalized integrator to realize zero-steady state error. The virtual admittance control system is designed accordingly. Matlab simulation and experiments verify that,the control strategy can not only realize no-ripple voltage control and real-time controllable power factor under unbalanced three-phase voltage with its stable performance,hut also need not to detect three-phase positive and negative sequence ac currents respectively, resulting in the improvement of system speediness. The introduced generalized integrator also has simple discrete iterative algorithm to greatly reduce calculation time.