A power converter for a power system performs power control of a power system by using a first control value derived based on a first stabilization command value for causing a voltage on a first DC bus to be within a first range and a first control command value different from the first stabilization command value. A power converter for a solar cell performs power control of a solar cell by using a second control value derived based on a second stabilization command value for causing a voltage on a second DC bus to be within a second range and a second control command value different from the second stabilization command value. The first range is narrower than the second range.