Thyristor converter system with higher harmonics suppression

A converter system for higher harmonic suppression, adapted to be coupled to an AC power source, said system comprising:

• a first input portion adaptable to be connected to an AC power source defining a power source side;
• a second input portion interconnected with said first input portion adaptable to be connected to a system load defining an AC load side;
• semiconductor converter circuit having a predetermined rise and fall time, said semiconductor converter circuit including semiconductor switching elements coupled across the AC power source for converting AC power supplied from the AC power source into DC power having an input connected to said first and second input portions and an output connectable to a branch load having a large time constant;
• measurement means for measuring electrical parameters at said first input portion, said second input portion and a connection point of said first and second input portions and the converter circuit input;
• means for determining control delay angels and overlap angles of voltage and current supplied from the AC power source;
• and
• a control circuit, having inputs coupled to outputs of the measurement means, for controlling the switching operations of the semiconductor switching elements of the semiconductor converter circuit, wherein the control circuit means controls the delay angle of the semiconductor switching elements such that the higher harmonics contents of a current flowing into the power source side are minimized.