Method and apparatus for balancing capacitors in a capacitor bank

A method and apparatus are for balancing capacitors in a capacitor bank. Three voltage levels are produced by a reference voltage source, to monitor the state of charge of the capacitors. The capacitor voltage on each capacitor is determined and is compared with the voltage levels. After the charging of the capacitors, normal operation starts when the capacitor voltage reaches the lowest voltage level and before it has reached the central voltage level. A balancing operation starts when the capacitor voltages of all the capacitors have reached the central voltage level, and ends when the capacitor voltage of all the capacitors has once again reached the lowest voltage level. When the lowest voltage level is reached once again, normal operation starts again. A fault is indicated upon reaching the highest voltage level.