A control method, the method being applied to a power system , the power system comprising a power battery , a permanent magnet motor , and an inverter , wherein the method comprising: obtaining (S201) a battery cell temperature of the power battery ; and sending (S202) a first control signal to the inverter when the battery cell temperature meets a preset power battery heating condition, wherein the first control signal is configured to control the inverter to convert a current provided by the power battery into an alternating current with a randomly changing frequency, and the alternating current with a randomly changing frequency is configured to supply power to the permanent magnet motor ; being the method characterized in that before the sending a first control signal to the inverter , the method further comprises: generating (S302) a plurality of set frequencies randomly, and determining duration of each set frequency according to each set frequency; determining (S303) a reference value sequence of a d-axis component according to the set frequencies and the duration of each set frequency, and setting a reference value sequence of a q-axis component to a zero sequence; and generating (S304) the first control signal according to the reference value sequence of the d-axis component, the reference value sequence of the q-axis component, and a motor parameter of the permanent magnet motor . obtaining (S201) a battery cell temperature of the power battery ; and sending (S202) a first control signal to the inverter when the battery cell temperature meets a preset power battery heating condition, wherein the first control signal is configured to control the inverter to convert a current provided by the power battery into an alternating current with a randomly changing frequency, and the alternating current with a randomly changing frequency is configured to supply power to the permanent magnet motor ; being the method characterized in that before the sending a first control signal to the inverter , the method further comprises: generating (S302) a plurality of set frequencies randomly, and determining duration of each set frequency according to each set frequency; determining (S303) a reference value sequence of a d-axis component according to the set frequencies and the duration of each set frequency, and setting a reference value sequence of a q-axis component to a zero sequence; and generating (S304) the first control signal according to the reference value sequence of the d-axis component, the reference value sequence of the q-axis component, and a motor parameter of the permanent magnet motor . generating (S302) a plurality of set frequencies randomly, and determining duration of each set frequency according to each set frequency; determining (S303) a reference value sequence of a d-axis component according to the set frequencies and the duration of each set frequency, and setting a reference value sequence of a q-axis component to a zero sequence; and generating (S304) the first control signal according to the reference value sequence of the d-axis component, the reference value sequence of the q-axis component, and a motor parameter of the permanent magnet motor . <EOS>