Method of operating electrical supply system, involves operating inverter at operating point in such manner that voltage level of half of average of rated voltage and maximum allowable voltage is present at entry point

摘要

The method involves accepting the voltage of upper voltage level with primary voltage, and stepping down the voltage of lower voltage level with secondary voltage. An inverter (11) is provided to convert the direct current (DC) power of DC power source (9) into alternating current that is fed to the upper voltage level. The inverter is operated at an operating point at which voltage-raising reactive power is fed into the upper voltage level in such a manner that the voltage level of half of the average of rated voltage and the maximum allowable voltage is present at entry point (6).