Energization control system and sensor unit

An energization control system, comprising:

• a sensor unit including
• a magnetic detection portion detecting a magnetic flux density of a magnetic flux generated at a surrounding of a conductor in response to a current flowing in the conductor of an electrical apparatus;
• a temperature detection portion detecting a temperature level within a package in which the magnetic detection portion is disposed;
• a correction portion correcting a temperature characteristic of a detection result of the magnetic detection portion based on the detected temperature level;
• and
• an output portion outputting temperature information indicating the detected temperature level;
• and
• a control unit including
• a control portion controlling a current flowing in a heating element of the electrical apparatus based on the temperature information, wherein
• the conductor corresponds to a plurality of bus bars electrically connecting a three-phase rotary electric machine to a frequency converter converting a frequency of at least one of an electric power inputted to the three-phase rotary electric machine and an electric power outputted from the three-phase rotary electric machine;
• the heating element corresponds to a plurality of switching elements of the frequency converter;
• in a case where the control portion determines that a current value of the current flowing in each of the bus bars is constantly continued for a predetermined time, the control portion specifies the bus bar flowing the current having a greatest current value among the current values of the currents flowing in each of the bus bars, the control portion estimating a temperature increase value of the switching element controlling the current flowing in the specified bus bar based on the temperature information, the control portion limiting a duty ratio of on-state of the switching element in a case where the estimated temperature increase value is equal to or greater than a preset temperature increase value.