INDUCTION MOTOR TYPE ELECTRIC RAILCAR CONTROLLER

摘要

PURPOSE:To enable to reduce the low frequency component of an input current by superposing the output of an AC generator operated in the prescribed phase difference and magnification synchronously with a variable voltage variable frequency inverter on the input current. CONSTITUTION:A variable voltage variable frequency inverter 7 is controlled by the output fINN1 of an adder/subtractor 11 by the sum (at power drive time) or the difference (at regenerative time) of the output fr of a rotary frequency calculator 10 and the output fsp of a slip frequency pattern generator. An AC generator 5 is controlled by the frequency fINN2 of six times of the frequency fINN1 controlled by the inverter 7, and fed into the input current through a transformer 4 to cancel each other. Thus, the low frequency ripple component in the input current can be reduced irrespective of the filter reactor 3 and the filter capacitor 6 to decrease the capacity of the filter capacitor.