Search

CN-122001070-A - Uninterruptible power supply and control method thereof

CN122001070ACN 122001070 ACN122001070 ACN 122001070ACN-122001070-A

Abstract

An uninterrupted power supply and a control method thereof are applied to the technical field of power supplies, an alternating current input end of the uninterrupted power supply is used for being connected with an alternating current power grid, and an alternating current output end of the uninterrupted power supply is used for being connected with an alternating current load. The uninterruptible power supply comprises a rectifier, an inverter, a direct current bus, a bypass switch circuit and a controller. The bypass switch circuit is connected between the alternating current input end and the alternating current output end of the uninterrupted power supply and used for connecting or disconnecting the alternating current input end and the alternating current output end of the uninterrupted power supply. And the controller is used for disconnecting the electric connection between the alternating current output end and the load, controlling the communication of the bypass switch circuit and controlling the work of the rectifier and the inverter under the condition that the placement time of the uninterruptible power supply is greater than a time threshold value or the humidity inside the uninterruptible power supply is greater than a humidity threshold value. By adopting the application, dehumidification can be completed by self-working heating of the circuit in the uninterruptible power supply without additionally adding a heating circuit, thereby reducing the cost of the uninterruptible power supply.

Inventors

  • HU ZHILUN

Assignees

  • 华为技术有限公司

Dates

Publication Date
20260508
Application Date
20260112

Claims (18)

  1. 1. The utility model provides an uninterrupted power source, its characterized in that, uninterrupted power source's AC input is used for connecting ac power grid, uninterrupted power source's AC output is used for connecting ac load, uninterrupted power source includes rectifier, dc-to-ac converter, direct current generating line, bypass switch circuit and controller, wherein: The rectifier is connected between the alternating current input end and the direct current bus, and the inverter is connected between the direct current bus and the alternating current output end; The bypass switch circuit is connected between the alternating current input end and the alternating current output end and is used for connecting or disconnecting the alternating current input end and the alternating current output end; the controller is used for disconnecting the electric connection between the alternating current output end and the load under the condition that the placement time of the uninterruptible power supply is larger than a time threshold or the humidity inside the uninterruptible power supply is larger than a humidity threshold, controlling the bypass switch circuit to be communicated with the electric connection between the alternating current input end and the alternating current output end, and controlling the rectifier and the inverter to work.
  2. 2. The uninterruptible power supply of claim 1, wherein the controlling operation of both the rectifier and the inverter comprises: And controlling the rectifier to work so that the voltage of the direct current bus is a first voltage, and then controlling the inverter to work, wherein the difference value between the first voltage and the voltage peak value of the alternating current power grid is smaller than a voltage threshold value.
  3. 3. The uninterruptible power supply of claim 1 or 2, further comprising a fan; The controller is further configured to control, when the standing time of the uninterruptible power supply is greater than a duration threshold or the humidity inside the uninterruptible power supply is greater than a humidity threshold, a wind speed gear of forward rotation of the fan to be gradually increased from a lowest wind speed gear to a preset wind speed gear before controlling both the rectifier and the inverter to work, wherein the fan is used for supplying air to the inside of the uninterruptible power supply when forward rotation of the fan.
  4. 4. The ups of claim 3, wherein the controller is further configured to control the fan to rotate in a reverse direction if a time of placement of the ups is greater than a duration threshold or a humidity within the ups is greater than a humidity threshold and prior to controlling the fan to rotate in a forward direction.
  5. 5. The uninterruptible power supply of claim 2, further comprising a positive bus capacitor and a negative bus capacitor, wherein the dc bus comprises a dc bus anode and a dc bus cathode, and wherein the positive bus capacitor and the negative bus capacitor are serially connected in sequence between the dc bus anode and the dc bus cathode; The controller is further configured to control the rectifier to operate to adjust the voltage of the dc bus to increase gradually from a second voltage to a third voltage when the standing time of the ups is greater than a duration threshold or the humidity inside the ups is greater than a humidity threshold, and before the voltage of the dc bus is controlled to be the first voltage, where the third voltage is smaller than a sum of the rated voltage of the positive bus capacitor and the rated voltage of the negative bus capacitor.
  6. 6. The uninterruptible power supply of claim 5, wherein the controller is further configured to adjust a total duration for which the voltage of the dc bus is stepped up from the second voltage to the third voltage based on the settling time, wherein the total duration is positively correlated with the settling time.
  7. 7. The uninterruptible power supply of any of claims 1 to 6, further comprising a fan; The controller is further configured to adjust, after the inverter is controlled to operate, an output current value of the inverter and a wind speed gear of forward rotation of the fan based on a difference between an internal temperature of the uninterruptible power supply and a preset temperature, so as to reduce an absolute value of the difference, wherein the fan is used for supplying air to the inside of the uninterruptible power supply when forward rotation of the fan, and the rectifier and the inverter are controlled to stop operating when a total duration of the difference, where the absolute value of the difference is less than or equal to a difference threshold, reaches a preset duration.
  8. 8. The uninterruptible power supply of claim 7, wherein when the difference is greater than 0, the output current value of the inverter is inversely related to the difference, the wind speed gear is positively related to the difference, when the difference is less than 0, the output current value of the inverter is positively related to the absolute value of the difference, the wind speed gear is inversely related to the absolute value of the difference, and the preset temperature is inversely related to the preset duration.
  9. 9. The uninterruptible power supply of any of claims 5 to 8, further comprising a slow-start circuit for obtaining electrical energy from the ac grid to power the dc bus; The controller is further configured to control the slow-start circuit to operate before controlling the voltage of the dc bus to gradually increase from the second voltage to the third voltage when the placement time of the uninterruptible power supply is greater than a duration threshold or the humidity inside the uninterruptible power supply is greater than a humidity threshold, so that the voltage of the dc bus gradually increases to the second voltage.
  10. 10. The control method of the uninterruptible power supply is characterized by being applied to the uninterruptible power supply, wherein an alternating current input end of the uninterruptible power supply is used for being connected with an alternating current power grid, an alternating current output end of the uninterruptible power supply is used for being connected with an alternating current load, the uninterruptible power supply comprises a rectifier, an inverter, a direct current bus, a bypass switch circuit and a controller, wherein the rectifier is connected between the alternating current input end and the direct current bus, the inverter is connected between the direct current bus and the alternating current output end, and the bypass switch circuit is connected between the alternating current input end and the alternating current output end and is used for connecting or disconnecting the connection between the alternating current input end and the alternating current output end; The method comprises the following steps: And under the condition that the placing time of the uninterruptible power supply is greater than a time threshold or the humidity inside the uninterruptible power supply is greater than a humidity threshold, disconnecting the electric connection between the alternating current output end and the load, controlling the bypass switch circuit to be communicated with the electric connection between the alternating current input end and the alternating current output end, and controlling the rectifier and the inverter to work.
  11. 11. The method of claim 10, wherein the controlling operation of both the rectifier and the inverter comprises: And controlling the rectifier to work so that the voltage of the direct current bus is a first voltage, and then controlling the inverter to work, wherein the difference value between the first voltage and the voltage peak value of the alternating current power grid is smaller than a voltage threshold value.
  12. 12. The method of claim 10 or 11, wherein the uninterruptible power supply further comprises a fan; The method further comprises the steps of: And under the condition that the placing time of the uninterruptible power supply is greater than a time threshold or the humidity inside the uninterruptible power supply is greater than a humidity threshold, and before the rectifier and the inverter are controlled to work, the wind speed gear for forward rotation of the fan is controlled to be gradually increased from the lowest wind speed gear to a preset wind speed gear, wherein the fan is used for supplying air to the inside of the uninterruptible power supply when forward rotation of the fan.
  13. 13. The method according to claim 12, wherein the method further comprises: And controlling the fan to rotate reversely before controlling the fan to rotate forwardly under the condition that the standing time of the uninterruptible power supply is larger than a duration threshold value or the humidity inside the uninterruptible power supply is larger than a humidity threshold value.
  14. 14. The method of claim 11, wherein the uninterruptible power supply further comprises a positive bus capacitor and a negative bus capacitor, the dc bus comprising a dc bus positive electrode and a dc bus negative electrode, the positive bus capacitor and the negative bus capacitor being serially connected in sequence between the dc bus positive electrode and the dc bus negative electrode; The method further comprises the steps of: And controlling the rectifier to work to adjust the voltage of the direct current bus to be increased gradually from the second voltage to the third voltage under the condition that the standing time of the uninterruptible power supply is larger than a time threshold or the humidity inside the uninterruptible power supply is larger than a humidity threshold, and controlling the voltage of the direct current bus to be the first voltage before controlling the voltage of the direct current bus to be smaller than the sum of the rated voltage of the positive bus capacitor and the rated voltage of the negative bus capacitor.
  15. 15. The method of claim 14, wherein the method further comprises: and based on the placement time, adjusting the total duration of the voltage of the direct current bus, which is increased from the second voltage to the third voltage, wherein the total duration is positively correlated with the placement time.
  16. 16. The method of any one of claims 10-15, wherein the uninterruptible power supply further comprises a fan; The method further comprises the steps of: After the inverter is controlled to work, based on the difference value between the internal temperature of the uninterruptible power supply and the preset temperature, adjusting the output current value of the inverter and the wind speed gear of forward rotation of the fan to reduce the absolute value of the difference value, wherein the fan is used for supplying air to the interior of the uninterruptible power supply when rotating forward; and controlling the rectifier and the inverter to stop working under the condition that the total duration of the difference value, of which the absolute value is smaller than or equal to the difference value threshold value, reaches the preset duration.
  17. 17. The method of claim 16, wherein the output current value of the inverter is inversely related to the difference when the difference is greater than 0, the wind speed gear is positively related to the difference, the output current value of the inverter is positively related to the absolute value of the difference when the difference is less than 0, the wind speed gear is inversely related to the absolute value of the difference, and the preset temperature is inversely related to the preset duration.
  18. 18. The method of any one of claims 14-17, wherein the uninterruptible power supply further comprises a slow-start circuit for obtaining electrical energy from the ac grid to power the dc bus; The method further comprises the steps of: And controlling the slow-start circuit to work before controlling the voltage of the direct current bus to gradually increase from the second voltage to the third voltage under the condition that the standing time of the uninterruptible power supply is larger than a time threshold or the humidity inside the uninterruptible power supply is larger than a humidity threshold, so that the voltage of the direct current bus gradually increases to the second voltage.

Description

Uninterruptible power supply and control method thereof Technical Field The application relates to the technical field of power supplies, in particular to an uninterruptible power supply and a control method thereof. Background The uninterruptible power supply (Uninterrupted Power Supply, UPS) is delivered from factory to actual power on, and is required to be subjected to field construction such as factory transportation, cabinet installation, input and output wiring and the like. In the field construction process, because the air conditioner in the machine room is also in the installation and measurement stage and does not run formally, the temperature and humidity of the environment of the machine room are unreliable, and the delivery period is usually at least 3 to 6 months. Because the power modules in the UPS require ventilation and heat dissipation, the UPS cannot be made as a completely sealed cabinet. The lead time of the UPS is longer, and moisture in the air can enter the power module through the air inlet of the UPS in the period of time, so that key devices (such as semiconductor power devices and thin film capacitors) of the power module are wetted. After the device is wetted, the insulation performance is reduced, the voltage withstand capability is reduced, the wetted oxide layer is corroded, the resistance value is changed and the like can be caused, so that the reliability of the UPS is reduced. At present, the UPS dehumidifies devices in the UPS by adding a heating plate to heat, so that the reliability of the UPS is improved. This approach requires the addition of additional heat patches and their control circuitry, resulting in increased circuit and bulk costs for the UPS. Therefore, it is particularly important how to reduce the humidity of devices in a UPS without adding additional circuitry. Disclosure of Invention The application provides an uninterruptible power supply and a control method thereof, which can complete dehumidification through self-working heating of a circuit in the uninterruptible power supply without additionally adding a heating circuit, thereby effectively reducing the cost of the uninterruptible power supply. In a first aspect, the present application provides an uninterruptible power supply having an ac input for connection to an ac power grid and an ac output for connection to an ac load. The uninterruptible power supply comprises a rectifier, an inverter, a direct current bus, a bypass switch circuit and a controller. The rectifier is connected between the alternating current input end of the uninterruptible power supply and the direct current bus, and the inverter is connected between the direct current bus and the alternating current output end of the uninterruptible power supply. The bypass switch circuit is connected between the alternating current input end and the alternating current output end of the uninterrupted power supply and used for connecting or disconnecting the alternating current input end and the alternating current output end of the uninterrupted power supply. And the controller is used for disconnecting the electric connection between the alternating current output end and the load under the condition that the standing time of the uninterruptible power supply is greater than a time threshold value or the humidity inside the uninterruptible power supply is greater than a humidity threshold value, controlling the bypass switch circuit to be communicated with the electric connection between the alternating current input end and the alternating current output end, controlling the rectifier and the inverter to work, and enabling the electric energy output by the alternating current power grid to return to the alternating current power grid after passing through the rectifier, the inverter and the bypass switch circuit in sequence, namely enabling the uninterruptible power supply to be in a self-circulation mode. The placing time of the uninterruptible power supply is the time interval between the delivery time of the uninterruptible power supply and the first power-on time of the uninterruptible power supply. It can be understood that under the condition that the uninterruptible power supply needs to dehumidify, the electric connection between the alternating current output end of the uninterruptible power supply and the alternating current load can be disconnected, the rectifier, the inverter and the bypass switch circuit are controlled to work, a current loop which sequentially passes through the rectifier, the inverter and the bypass switch circuit after being started from the alternating current power grid and returns to the alternating current power grid is formed, and therefore the uninterruptible power supply is dehumidified by the work of the rectifier, the inverter and the bypass switch circuit, and the reliability and the health of the uninterruptible power supply are improved. Because the dehumidification mode is completed by the s