Control method for uninterruptible power supply system, controller, and uninterruptible power supply system

A controller for use in an uninterruptible power supply system, wherein:

• the uninterruptible power supply system comprises the controller, a bypass power supply branch, an inverter power supply branch, and an energy storage battery, the bypass power supply branch and the inverter power supply branch are connected in parallel and then are connected to a load, the energy storage battery is connected to the inverter power supply branch, the bypass power supply branch comprises a first switch device and a second switch device that are connected in anti-parallel, the inverter power supply branch comprises an inverter and a direct current to direct current (DC/DC) converter that are connected in series, and the controller is separately connected to the inverter and the DC/DC converter;
• and
• the controller comprises at least one processor and one or more memories coupled to the at least one processor, wherein the one or more memories store programming instructions for execution by the at least one processor to perform operations comprising:
• when the bypass power supply branch supplies the power to the load, outputting a first drive signal to the first switch device and outputting a second drive signal to the second switch device;
• and
• controlling the first drive signal and the second drive signal to have a phase difference with an input voltage of the bypass power supply branch;
• or
• when a load current of the bypass power supply branch is less than a first threshold, outputting an inverter control signal to control the inverter power supply branch to charge the energy storage battery;
• or
• when a current of the inverter power supply branch flows back to an input end of the bypass power supply branch, turning off the first switch device and the second switch device via the inverter power supply branch,
• wherein the operations comprise:
• outputting an inverter control signal to the inverter power supply branch to control the inverter power supply branch to supply a power to the load;
• detecting whether the current of the inverter power supply branch flows back to an input side of the bypass power supply branch;
• and
• when the current of the inverter power supply branch flows back to the input side of the bypass power supply branch, controlling an output voltage of the inverter power supply branch, to turn off the first switch device and the second switch device, wherein when the current of the inverter power supply branch flows back to the input side of the bypass power supply branch, and the input voltage is at a phase angle of 0° to 90° or 180° to 270°, the output voltage of the inverter power supply branch is controlled, to turn off the first switch device and the second switch device.

An uninterruptible power supply system, wherein:

• the uninterruptible power supply system comprises a controller, a bypass power supply branch, an inverter power supply branch, and an energy storage battery, a load, and a controller, the bypass power supply branch and the inverter power supply branch are connected in parallel and then are connected to the load, the energy storage battery is connected to the inverter power supply branch, the bypass power supply branch comprises a first switch device and a second switch device that are connected in anti-parallel, the bypass power supply branch and the inverter power supply branch are separately connected to the controller, the inverter power supply branch comprises an inverter and a direct current to direct current (DC/DC) converter that are connected in series, and the controller is separately connected to the inverter and the DC/DC converter;
• and
• the controller comprise at least one processor and one or more memories coupled to the at least one processor, wherein the one or more memories store programming instructions for execution by the at least one processor to perform operations comprising:
• when the bypass power supply branch supplies the power to the load, outputting a first drive signal to the first switch device and outputting a second drive signal to the second switch device;
• and
• controlling the first drive signal and the second drive signal to have a phase difference with an input voltage of the bypass power supply branch;
• or
• when a load current of the bypass power supply branch is less than a first threshold, outputting an inverter control signal to control the inverter power supply branch to charge the energy storage battery;
• or
• when a current of the inverter power supply branch flows back to an input end of the bypass power supply branch, turning off the first switch device and the second switch device via the inverter power supply branch,
• wherein the operations comprise:
• outputting an inverter control signal to the inverter power supply branch to control the inverter power supply branch to supply a power to the load;
• detecting whether the current of the inverter power supply branch flows back to an input side of the bypass power supply branch;
• and
• when the current of the inverter power supply branch flows back to the input side of the bypass power supply branch, controlling an output voltage of the inverter power supply branch, to turn off the first switch device and the second switch device, comprising:
• controlling the inverter to output a voltage signal at a first level, to turn off the first switch device and the second switch device.