CONTROLLER FOR ELECTRIC ROLLING STOCK

摘要

PROBLEM TO BE SOLVED: To perform secure detection stably for ground fault of DC line in a variable voltage and variable frequency inverter and ground fault on AC motor side in a controller for AC motor with the variable voltage and variable frequency inverter using a DC power supply including positive output terminals and negative output terminals and having neutral grounding. SOLUTION: This controller includes a DC ground fault detecting means 18 for detecting a difference between ground fault current passing through a ground resistor 4b at the DC line ground fault in the variable voltage and variable frequency inverter 10A and a current of an input DC power supply passing through the positive or negative side of the variable voltage and variable frequency inverter 10A in an ordinary case.