A power conversion system includes a first rectifier and a second rectifier. The first rectifier is configured to operate at a first operating frequency. The first rectifier is configured to be connected with a three-phase power source. A first amount of power flows through the first rectifier from the three-phase power source. The second rectifier is configured to operate at a second operating frequency. The second rectifier is configured to be connected in parallel with the first rectifier, and a second amount of power flows through the second rectifier from the three-phase power source. The second operating frequency is higher than the first operating frequency, and the second amount of power is a fraction of the first amount of power.