A Control Technique for Three-Phase UPS Inverters with Dynamic Response Improvement Feature

In this paper, a control technique based on system modeling of three-phase LC-filtered uninterruptible power supply (UPS) voltage source inverters (VSIs) is presented. The presented technique has the ability to improve the dynamic response of the UPS system. The control technique is established in the dq reference frame of the UPS system. The reference currents required in the control algorithm are obtained through proportional-integral (PI) regulators. The PI regulators express the reference current components by regulating the output voltages in the d- and q-axes. Besides, a virtual time constant is included in the switching functions which offer an opportunity to adjust the current dynamics as desired. Unlike the existing control approaches, the proposed control technique does not need an extra active damping signal. The feasibility of the proposed technique is confirmed through simulation results in MATLAB/Simulink environment.