基于虚拟磁链定向的PWM整流器直接功率控制研究

摘要

提出一种基于虚拟磁链定向的PWM整流器直接功率控制策略.该控制策略将传统的对电流有功、无功分量进行控制的方法改为直接对PWM整流器有功功率、无功功率进行控制,并采用虚拟磁链定向方法进行坐标变换,提高了整个变频调速系统的动态性能和可靠性,降低了系统成本；采用一种虚拟磁链积分初值估算方法来辨识磁链初值,在PWM整流器启动后将积分得到的虚拟磁链减去磁链初值,从而消除虚拟磁链中的直流分量.Matlab仿真结果证明了该控制策略的有效性.%The paper proposed a direct power control strategy of PWM rectifier based on virtual flux orientation. The strategy controls active power and reactive power of PWM rectifier instead of active and reactive current components of traditional control methods and uses virtual flux orientation method for coordinate transformation, so as to improve dynamic performance and reliability of whole frequency-conversion speed-regulation system and reduce system cost. Besides, the strategy uses an estimate method of initial integration value of virtual flux to identify initial virtual flux, which would be subtracted from the integration value of virtual flux after PWM rectifier starting, so as to eliminate DC component in virtual flux. The Matlab simulation result verified validity of the strategy.