A voltage control method, applied to a voltage source inverter, wherein the voltage source inverter comprises a bus capacitor, a bidirectional power tube, a filter inductor, and a filter capacitor, the bus capacitor is connected to one end of the bidirectional power tube, the other end of the bidirectional power tube is connected to one end of the filter inductor, the other end of the filter inductor is connected to the filter capacitor, and the method comprises: respectively obtaining a first feedback current and a first feedback voltage from an output end of the filter inductor and an output end of the filter capacitor; obtaining a first duty cycle and a second duty cycle, a maximum current reference value, and a minimum current reference value in a double current loop, wherein the first duty cycle is greater than the second duty cycle, and wherein the first duty cycle is obtained based on the first feedback current and the maximum current reference value and the second duty cycle is obtained based on the first feedback current and the minimum current reference value; obtaining a third duty cycle based on the first feedback voltage and a voltage reference value in a voltage loop; and selecting one of the first duty cycle, the second duty cycle, and the third duty cycle, and controlling the bidirectional power tube, so that a duty cycle of the bidirectional power tube is between the first duty cycle and the second duty cycle; characterized in that the first feedback current and the first feedback voltage are obtained in a stationary coordinate system; the obtaining a first duty cycle and a second duty cycle based on the first feedback current, a maximum current reference value, and a minimum current reference value in a current loop comprises: performing coordinate system conversion on the first feedback current, to obtain a second feedback current in a rotating coordinate system; and the obtaining a third duty cycle based on the first feedback voltage and a voltage reference value in a voltage loop comprises: performing coordinate conversion on the first feedback voltage, to obtain a second feedback voltage in the rotating coordinate system; and obtaining the third duty cycle based on the second feedback voltage and the voltage reference value in the voltage loop. respectively obtaining a first feedback current and a first feedback voltage from an output end of the filter inductor and an output end of the filter capacitor; obtaining a first duty cycle and a second duty cycle, a maximum current reference value, and a minimum current reference value in a double current loop, wherein the first duty cycle is greater than the second duty cycle, and wherein the first duty cycle is obtained based on the first feedback current and the maximum current reference value and the second duty cycle is obtained based on the first feedback current and the minimum current reference value; obtaining a third duty cycle based on the first feedback voltage and a voltage reference value in a voltage loop; and selecting one of the first duty cycle, the second duty cycle, and the third duty cycle, and controlling the bidirectional power tube, so that a duty cycle of the bidirectional power tube is between the first duty cycle and the second duty cycle; characterized in that the first feedback current and the first feedback voltage are obtained in a stationary coordinate system; the obtaining a first duty cycle and a second duty cycle based on the first feedback current, a maximum current reference value, and a minimum current reference value in a current loop comprises: performing coordinate system conversion on the first feedback current, to obtain a second feedback current in a rotating coordinate system; and the obtaining a third duty cycle based on the first feedback voltage and a voltage reference value in a voltage loop comprises: performing coordinate conversion on the first feedback voltage, to obtain a second feedback voltage in the rotating coordinate system; and obtaining the third duty cycle based on the second feedback voltage and the voltage reference value in the voltage loop. performing coordinate conversion on the first feedback voltage, to obtain a second feedback voltage in the rotating coordinate system; and obtaining the third duty cycle based on the second feedback voltage and the voltage reference value in the voltage loop.