Electric train drive control device

A drive control device for an electric train, comprising:

• a switch for connecting or opening direct-current electric power;
• a power converter into which the direct-current electric power is input via the switch between two terminals on an input side, for converting the direct-current electric power into alternating-current electric power through a switching operation, and driving an alternating-current rotating machine connected to an output side;
• a voltage detector for detecting voltage between the two terminals;
• a power controller for controlling the power converter such that when the voltage detected by the voltage detector exceeds a predetermined open-circuit voltage, the switch opens and regenerative brake power is reduced by the alternating-current rotating machine in a predetermined reduction pattern having a ramp reduction time longer than zero;
• a filter capacitor connected between the two terminals;
• and
• a capacitor voltage regulator connected between the two terminals in parallel with the filter capacitor and having a switching device;
• wherein the power controller intermittently controls the switching device and regulates a charge amount in the filter capacitor so that the detected voltage is not less than a first voltage and not greater than a second voltage over the ramp reduction time, and
• wherein the power controller sets a conduction ratio of the switching device to be zero at the timing when a voltage deviation reaches zero or a negative value from a positive value, and the power controller starts controlling in such a manner that as the voltage deviation increases, the conduction ratio increases at the timing when the voltage deviation reaches a positive value from zero or a negative value, the voltage deviation being determined by subtracting a third voltage from the detected voltage, wherein the third voltage is greater than the first voltage and less than the second voltage.