Uninterruptible power supply circuit

An uninterruptible power supply circuit, comprising:

• a bidirectional selector switch;
• a first-type bidirectional converter;
• a second-type bidirectional converter;
• an energy storage apparatus;
• a filtering apparatus;
• and
• a controller,
• wherein a first end of the bidirectional selector switch is connected to an alternating-current end of the first-type bidirectional converter, a second end is alternatively connected to an alternating-current power supply or the energy storage apparatus, and a control end is connected to a first output end of the controller,
• wherein a direct-current end of the first-type bidirectional converter is connected to the filtering apparatus, a control end is connected to a second output end set of the controller, and an operating status of the first-type bidirectional converter comprises rectifying, inverting, boosting or bucking,
• wherein a direct-current end of the second-type bidirectional converter is connected to the filtering apparatus, an alternating-current end is connected to a load, a control end is connected to a third output end set of the controller, and an operating status of the second-type bidirectional converter comprises inverting or rectifying, and
• wherein the controller is configured to:
• generate a control signal for controlling the bidirectional selector switch to connect to the energy storage apparatus when the energy storage apparatus needs to be charged,
• generate a control signal for controlling the first-type bidirectional converter to be in a bucking state when the energy storage apparatus needs to be charged,
• generate a control signal for controlling the second-type bidirectional converter to be in a rectifying state when the energy storage apparatus needs to be charged,
• output the control signal for controlling the bidirectional selector switch to connect to the energy storage apparatus when the energy storage apparatus discharges,
• generate a control signal for controlling the first-type bidirectional converter to be in a boosting state when the energy storage apparatus discharges, and
• generate a control signal for controlling the second-type bidirectional converter to be in an inverting state when the energy storage apparatus discharges.