Temperature raising controller

A temperature raising controller for use with an electrical power system, the electrical power system comprising:

• an electrical storage device;
• a rotating electrical machine which includes multi-phase windings;
• an inverter which includes upper arm switches and lower arm switches, each of the upper arm switches and a respective one of the lower arm switches being connected in series with each other for a respective one of multiple phases, each of joints of the upper arm switches to the lower arm switches being connected to a first end of a corresponding one of the multi-phase windings;
• a positive electrical path which connects high potential terminals of the upper arm switches to a positive terminal of the electrical storage device;
• a negative electrical path which connects low potential terminals of the lower arm switches to a negative terminal of the electrical storage device;
• a capacitor which is disposed between the positive electrical path and the negative electrical path in electrical connection therewith;
• and
• a power supply switch which is disposed between the electrical storage device and the capacitor in at least one of the positive electrical path and the negative electrical path,
• the temperature raising controller works to control a switching operation of the inverter to create a flow of ripple current in a form of a d-axis current between the electrical storage device and the capacitor with the power supply switch closed, thereby raising temperature of the electrical storage device, the temperature raising controller comprising:
• a determiner which determines whether an overvoltage condition which results in the capacitor being in an overvoltage state is met during execution of a temperature-raising control task for electrical storage device;
• and
• a controller which, when the determiner determines that the overvoltage condition is met, works to perform a condition control mode which opens a first switch combination that is one of a first combination of the upper arm switches and a second combination of the lower arm switches and also closes at least one of the upper arm switches or the lower arm switches in a second switch combination that is other of the first and second combinations with the power supply switch closed to circulate electrical current between the inverter and the rotating electrical machine.