Inverter and control method for sending pwm driver gating signal

An inverter, comprising:

• a primary-side circuit configured to convert a direct current into an alternating current;
• a transformer configured to perform voltage boosting or voltage bucking on the alternating current output by the primary-side circuit;
• a secondary-side circuit configured to:
• convert a frequency of the boosted or bucked alternating current and
• filter the alternating current obtained after frequency conversion, wherein the secondary-side circuit comprises a half-bridge circuit and a filter circuit, the half-bridge circuit comprises a bridge arm and at least two capacitors, the at least two capacitors are connected in series and then connected in parallel to the bridge arm, the bridge arm comprises an upper half bridge arm and a lower half bridge arm, a connection point between the upper half bridge arm and the lower half bridge arm is connected to a first end of a secondary-side winding of the transformer, a connection point between the at least two capacitors is connected to a second end of the secondary-side winding of the transformer, the upper half bridge arm and the lower half bridge arm each comprise a group of switching transistors, two switching transistors comprised in each group of the switching transistors each comprise a freewheeling diode connected in parallel, freewheeling directions of two freewheeling diodes connected in parallel in each group of the switching transistors are opposite, and the filter circuit is connected to the half-bridge circuit and is configured to output an alternating current voltage;
• and
• a controller configured to control the switching transistors of the bridge arm to be turned on and off, wherein
• the inverter comprises a first working mode and a second working mode,
• in the first working mode, three of the four switching transistors in the bridge arm are all turned on, and a remaining switching transistor is turned off, and,
• in the second working mode,
• the two switching transistors in the upper half bridge arm are both turned on, and the two switching transistors in the lower half bridge arm are both turned off, or
• the two switching transistors in the upper half bridge arm are both turned off, and the two switching transistors in the lower half bridge arm are both turned on;
• and
• the controller is further configured to:
• in response to a change of an absolute value of the alternating current voltage output by the filter circuit from being greater than an absolute value of a preset voltage threshold to being less than or equal to the absolute value of the preset voltage threshold, control the inverter to switch from the first working mode to the second working mode, to enable at least one and at most three of the four switching transistors comprised in the bridge arm to be turned on.