Method and system for warming-up electrolytic capacitor

Patent metadata

Field	Value
Publication number	US-2024396436-A1
Application number	US-202418669542-A
Country	US
Kind code	A1
Filing date	May 21, 2024
Priority date	May 23, 2023
Publication date	Nov 28, 2024
Grant date	—

Abstract

The disclosure provides a method and a system for warming-up an electrolytic capacitor. The method comprises: providing a power factor correction circuit comprising an AC terminal, a DC terminal and the electrolytic capacitor, wherein the DC terminal is connected in parallel to the electrolytic capacitor; determining whether it is necessary to perform a warm-up operation on the electrolytic capacitor; when it is determined to be necessary, generating a ripple current on the electrolytic capacitor by controlling an input current to flow into the AC terminal of the power factor correction circuit; and when the warmed-up state of the power factor correction circuit that is generated based on the ripple current matches a specified warmed-up exit condition, terminating the warm-up operation performed on the electrolytic capacitor.

First claim

What is claimed is:

1 . A method for warming-up an electrolytic capacitor, comprising:
providing a power factor correction circuit comprising an AC terminal, a DC terminal and the electrolytic capacitor, wherein the DC terminal is connected in parallel to the electrolytic capacitor; determining whether it is necessary to perform a warm-up operation on the electrolytic capacitor; when it is determined to be necessary, performing the warm-up operation which comprises: generating a ripple current on the electrolytic capacitor by controlling an input current to flow into the AC terminal of the power factor correction circuit; detecting a warmed-up state of the power factor correction circuit that is generated based on the ripple current; and when the warmed-up state matches a specified warmed-up exit condition, terminating the warm-up operation performed on the electrolytic capacitor of the power factor correction circuit.

2 . The method according to claim 1 , wherein the power factor correction circuit is capable of bidirectional current transmission.

3 . The method according to claim 1 , wherein the power factor correction circuit is a rectifier circuit, and an input voltage at the AC terminal of the power factor correction circuit is a sinusoidal voltage.

4 . The method according to claim 3 , wherein the input current and the input voltage of the power factor correction circuit have an equal period, and a phase difference of 90 degrees.

5 . The method according to claim 3 , wherein the input current of the power factor correction circuit is a DC signal, and the period of the input voltage is N times the period of the input current, where N is a positive integer.

6 . The method according to claim 5 , wherein the input current has a waveform of a full wave rectified sine wave, a triangular wave, a square wave or a sawtooth wave.

7 . The method according to claim 3 , wherein the input current of the power factor correction circuit is a constant current.

8 . The method according to claim 2 , wherein the power factor correction circuit has a topological structure of any one of a totem-pole type, a full-bridge type or a half-bridge type, or a topological structure formed by interleaving any one of the totem-pole type, the full-bridge type and the half-bridge type.

9 . The method according to claim 1 , wherein the DC terminal of the power factor correction circuit is electrically coupled to a load, and when the ripple current is generated on the electrolytic capacitor, the power factor correction circuit does not supply energy to the load.

10 . The method according to claim 1 , wherein a DC to DC converter is electrically connected between the electrolytic capacitor and the load,
wherein supplying no energy to the load by the power factor correction circuit comprises: controlling the DC to DC converter to be in a non-working state.

11 . The method according to claim 1 , wherein when the warmed-up state matches the specified warmed-up exit condition, terminating the warm-up operation performed on the electrolytic capacitor of the power factor correction circuit comprises:
determining whether a duration of the warm-up operation reaches a preset duration threshold, and when it is determined that the duration of the warm-up operation reaches the preset duration threshold, terminating the warm-up operation performed on the electrolytic capacitor of the power factor correction circuit.

12 . The method according to claim 1 , wherein when the warmed-up state matches the specified warmed-up exit condition, terminating the warm-up operation performed on the electrolytic capacitor of the power factor correction circuit comprises:
determining whether a device temperature in the warm-up operation reaches a preset temperature threshold, and when it is determined that the device temperature in the warm-up operation reaches the preset temperature threshold, terminating the warm-up operation performed on the electrolytic capacitor of the power factor correction circuit, wherein the device temperature is a temperature of the switch in the power factor correction circuit or the DC to DC converter, or a temperature of the electrolytic capacitor.

13 . The method according to claim 1 , wherein determining whether the warm-up operation is necessary to be performed on the electrolytic capacitor comprises:
detecting a temperature of an environment in which the electrolytic capacitor is located, which is defined as a first temperature; and comparing the first temperature with a first preset temperature, and when the first temperature is less than the first preset temperature, determining that it is necessary to perform a warm-up operation on the electrolytic capacitor; when the first temperature is equal to or greater than the first preset temperature, determining that it is unnecessary to perform a warm-up operation on the electrolytic capacitor.

14 . A system for warming-up an electrolytic capacitor, for implementing the method for warming-up the electrolytic capacitor according to claim 1 .

15 . A method for warming-up an electrolytic capacitor, comprising:
providing a DC to DC converter comprising a first terminal and a second terminal, an inverter comprising a DC terminal and an AC terminal, and an electrolytic capacitor, the electrolytic capacitor being connected in parallel to the second terminal of the DC to DC converter and the DC terminal of the inverter, and the first terminal of the DC to DC converter being connected to a DC source; determining whether it is necessary to perform a warm-up operation on the electrolytic capacitor; when it is determined to be necessary, periodically performing a charging operation and a discharging operation, wherein the charging operation comprises: controlling the DC to DC converter to charge the electrolytic capacitor with energy supplied from the DC source, and the discharging operation comprises: discharging energy of the electrolytic capacitor by the inverter; detecting a warmed-up state of the DC to DC converter or the inverter during the charging operation and/or the discharging operation; and when the warmed-up state matches a specified warmed-up exit condition, terminating the charging operation and the discharging operation performed on the electrolytic capacitor.

16 . The method according to claim 15 , wherein the charging operation further comprises: controlling the inverter to be in an open state, and controlling the DC to DC converter to convert the energy supplied from the DC source and to charge the electrolytic capacitor with the converted energy; and the discharging operation further comprises: controlling the inverter to be a short circuit state, and discharging energy transferred from the DC source through the DC to DC converter and energy of the electrolytic capacitor by using the inverter.

17 . The method according to claim 16 , wherein the inverter is a bridge circuit, wherein:
controlling the inverter to be in the open state comprises:
controlling each switch in the bridge circuit to be turned off such that the inverter is to be in the open state, and
controlling the inverter to be in the short circuit state comprises:
controlling each switch in the bridge circuit to be turned on such that the inverter is to be in the short circuit state.

18 . The method according to claim 15 , wherein the DC to DC converter is an isolated DC to DC converter, and periodically performing the charging operation and the discharging operation comprises:
performing a control of frequenc

Assignees

• Delta Electronics Shanghai Co

Inventors

• Zhang Jinfa
• Wang Xiaolei

Classifications

• H02M1/36

  Means for starting or stopping converters · CPC title

• H02M3/01

  Resonant DC/DC converters · CPC title

• H02M3/33573

  Full-bridge at primary side of an isolation transformer · CPC title

• H02M1/4233

  using a bridge converter comprising active switches · CPC title

• H02M1/007

  Plural converter units in cascade (push-pull DC/DC converters with pre-regulator H02M3/3374; DC-AC converters following a DC-DC stage including a high frequency transformer H02M7/4807; DC-AC converters following a DC-DC conversion stage generating periodically varying voltages H02M7/4826) · CPC title