The influence of the output impedance of the DC voltage source on the dynamic properties of the voltage source inverter for UPS system

In many cases, the voltage source inverter in a UPS system requires increasing its input DC voltage. Regardless of the specific solution, a DC/DC converter that stores energy in the inductance is usually applied. That is why it should be expected that this inductance multiplied by the square of the voltage increasing factor in connection with the DC/DC converter output capacitor will consist of the equivalent circuit on the inverter input. The aim of the paper is to demonstrate the impact of such equivalent impedance on the dynamic properties of the inverter. The investigation of the developed inverter model will allow the question of whether the choice of the appropriate feedback compensating the effects of the additional resonant frequencies in the magnitude frequency domain that are characteristic of the control function is necessary depending on DC/DC converter parameters to be answered. The paper shows both software simulations and experimental laboratory model measurements.