POWER CONVERSION SYSTEM

A power conversion system includes a converter, a current sensor, and a motor ECU. The converter is configured to boost a voltage by operating at a set carrier frequency. The current sensor detects a current flowing through the converter. The motor ECU executes control for protecting the converter. The motor ECU estimates a temperature rise amount of the converter according to at least one of the carrier frequency and a voltage ratio before and after boosting the converter, and a detected value of the current sensor, and executes control for suppressing the current flowing through the converter in a case where an integrated value of the temperature rise amount reaches a threshold.