Prediction of Voltage Stresses for Power Electronic System (LCLC) using Energy State Determination

The paper deals with the maximal and minimal overvoltage’s determination of power electronic systems having accumulated LC elements. These over-voltages depend on instantaneous energy states of system state variables. A new modified method of instantaneous calculation for state variables is used. It makes possible to specify the values of the state variables at any discrete time instant without having previous values, just initial ones at the beginning of the transient. Based on these values it is possible to estimate the voltage and current stresses of semiconductor elements and to circulate energy inside in power circuit. It is shown that maximal or minimal over-voltages depend on the instants of the transients whose knowledge is presented. Circulating energy makes it possible the correct operation of the power electronic system. Theoretical output results are confirmed by simulation experiments in Matlab/Simulink environment.