CONTROL OF A MODULAR CONVERTER HAVING DISTRIBUTED ENERGY STORES WITH THE AID OF AN OBSERVER FOR THE CURRENTS AND AN ESTIMATING UNIT FOR THE INTERMEDIATE CIRCUIT ENERGY

摘要

Methods and configurations controlling a converter having controllable power semiconductors, compare actual and target state values to obtain control difference values for a control unit producing setting voltage values. Control electronics provide control signals according to setting voltage values and transmit them to power semiconductors. The control unit generates voltage values so control difference values become small. Current and converter energy controls and energy balancing are performed jointly, actual state values are calculated by an observing unit based on setting voltage values considering measured current values and actual state intermediate-circuit energy values are calculated by an estimating unit considering measured intermediate-circuit energy values of positive and negative voltage sources. The observing and estimating units model the converter so actual state current and intermediate-circuit steady-state energy values correspond to error-free current and intermediate-circuit energy values. A periodic time-variant gain controller receives error-free values.