Control circuit for power converter

A control circuit for a power converter that is applicable to a system,

• the system including;
• a power supply;
• a rotating electric machine that is connected to the power supply;
• a power converter;
• an interruption switch that is provided on an electrical path that connects the power supply and the power converter;
• a smoothing capacitor that is connected on a side opposite the power supply from the interruption switch on the electrical path;
• and
• a series-connection body comprising a discharge resistor and a discharge switch that is connected in parallel to the smoothing capacitor, and
• the control circuit comprising:
• a discharge command unit that outputs, in response to the interruption switch being set to an on-state and in response to a controlled variable of the rotating electric machine being controlled to a command value, a discharge command for the smoothing capacitor;
• a discharge drive command unit that outputs a drive command for the discharge switch based on the discharge command that is outputted from the discharge command unit, the drive command including a plurality of on-pulse commands;
• a drive circuit that is connected to a gate of the discharge switch and performs drive control of the discharge switch based on the drive command that is outputted from the discharge drive command unit;
• an operation detecting unit that detects at least one of a gate voltage of the discharge switch and the drive command that is outputted from the discharge drive command unit;
• and
• a discharge determining unit that determines whether the discharge switch is in an on-state according to the plurality of on-pulse commands based on a detected signal of the operation detecting unit, wherein
• the discharge drive command unit and the drive circuit (i) are connected on a side opposite the power supply from the interruption switch on the electrical path and (ii) are configured to operate with the smoothing capacitor as a power supply source.