Electric power supply system for electric train which removes flickering in lighting

An AC power supply system comprising:

• an inverter for inverting DC power to AC power;
• a filter for passing components of said AC power having a frequency lower than a cut off frequency of said filter;
• first detecting means for detecting an amplitude of an output of said filter;
• second detecting means for detecting any deviation of said amplitude from a reference signal and outputting an error signal;
• first control means for controlling said inverter in accordance with said error signal output from said second detecting means;
• second control means, connected to receive said output of said filter, for detecting and removing flickering components from said output of said filter, said second control means comprising flickering component passing means for passing only said flickering components contained in said output of said filter;
• third detecting means for detecting a frequency of an output of said flickering component passing means;
• third sine wave generating means for generating a sine wave having a frequency substantially identical to that detected by said third detecting means;
• a phase shifter for shifting a phase of said sine wave generated by said third sine wave generating means, said sine wave having experienced a phase lag as a result of passing through said flickering component passing means;
• and
• an adder for adding together an output of said phase shifter and an output of said second detecting means so as to remove said flickering components from said error signal.