Deadbeat control method for single-phase UPS inverters with compensation of computation delay

Abstract

In existing deadbeat control techniques for single-phase UPS inverters, the pulse width of the inverter output voltage is limited by the computation time of the controlling processor. This limits the utilisation of the DC source voltage and slows the response of the control system. A deadbeat control technique is presented which eliminates these limitations by allowing the application of the newly computed pulse width with time delay. During this delay, the previously applied pulse width is preserved until it is updated by the new pulse width. This method requires the use of a load-dependent reference function for the inverter output voltage. However, the error in the load voltage caused by using a fixed reference function is shown to be negligible. Computer simulations are performed to verify the theoretical results and for comparison with existing methods. Experimental results are also presented to support the theoretical considerations.