US-12620831-B2 - Dual power supply transfer switch based on solid-state switch

US12620831B2US 12620831 B2US12620831 B2US 12620831B2US-12620831-B2

Abstract

A dual power supply transfer switch (SSATS) for switching between a first power supply (S 1 ) and a second power supply (S 2 ) to supply power to a load is provided, includes: a solid-state switch (SS); a mechanical switch (CTR); and a compensation power module (AUX). In the case that the S 1 fails in supplying power to the load, the AUX uses the S 2 to supply power to the load, and the output current of the S 1 is reduced. After satisfying the turn off condition for the SS, the SS turns off the S 1 , the CTR turns off the S 1 and turns on the S 2 . After the S 2 is adjusted to synchronize with the phase of the output current of the S 1 , the SS turns on the S 2 and the AUX stops outputting current. The SSATS provides advantages such as fast transfer, zero interruption, and short voltage sag time.

Inventors

Xiaohang CHEN
Haijun Zhao
Ying Shi
Jiamin Chen
Yangfeng Song
Qing Yang
Jihua Dong
Kunpeng Zhang

Assignees

SCHNEIDER ELECTRIC INDUSTRIES SAS

Dates

Publication Date: 20260505
Application Date: 20230630
Priority Date: 20220630

Claims (18)

1 . A dual power transfer switch for supplying uninterrupted power to a load, comprising: a first solid-state switch configured to selectively connect the load to a first AC power supply providing AC electrical power of a first phase; a second solid-state switch configured to selectively connect the load to a second AC power supply providing AC electrical power of a second phase; a first mechanical switch in series with the first solid-state switch; a second mechanical switch in series with the second solid-state switch; and a power supply unit configured to selectively receive AC electrical power from a selected one of the first and second power supplies, and to provide AC electrical power of a controlled phase to the load, wherein, during normal operation, the second solid-state switch is open and the first solid-state switch is closed, thereby connecting the load to the first power supply; a controller configured to: cause the power supply unit to receive AC electrical power of the second phase from the second power supply and to convert the AC electrical power of the second phase received therefrom to AC electrical power of the first phase; monitor the first power supply to detect a failure of the first power supply; and in response to detecting the failure of the first power supply: cause the first solid-state switch to open, thereby isolating the load from the first power supply; cause the power supply unit to provide the AC electrical power of the first phase to the load; cause the first mechanical switch to open and the second mechanical switch to close after causing the first solid-state switch to open; cause the power supply unit to transition the controlled phase of the AC electrical power provided to the load from the first phase to the second phase; and cause the second solid-state switch to close in response to the controlled phase of the AC electrical power provided by the power supply unit being synchronized with the second phase of the AC electrical power received from the second power supply, thereby connecting the load to the second power supply.
2 . The dual power transfer switch of claim 1 , wherein the controller causes the first solid-state switch to open in response to AC electrical current provided by the first power supply falling below a first current threshold.
3 . The dual power transfer switch of claim 1 , wherein the controller causes the first solid-state switch to open in response to AC electrical voltage provided by the power supply unit exceeding a predetermined voltage threshold.
4 . The dual power transfer switch of claim 1 , wherein the controller causes the first solid-state switch to open in response to AC electrical current provided by the power supply unit exceeding a predetermined current threshold.
5 . The dual power transfer switch of claim 1 , wherein the controller is further configured, in response to detecting the failure of the first power supply, to: cause the power supply unit to receive AC electrical power of the first phase from the first power supply and to convert the AC electrical power of the first phase received therefrom to AC electrical power of the second phase.
6 . The dual power transfer switch of claim 1 , wherein the controller is further configured to cause the second mechanical switch to close before causing the second solid-state switch to close.
7 . The dual power transfer switch of claim 1 , wherein the first and second mechanical switches are configured as a single-pole double-throw switch.
8 . The dual power transfer switch of claim 7 , wherein the second solid-state switch is closed after the first solid-state switch is opened.
9 . The dual power transfer switch of claim 1 , further comprising: a third mechanical switch configured to selectively connect the first power supply to an input of the power supply unit; and a fourth mechanical switch configured to selectively connect the second power supply to the input of the power supply unit.
10 . The dual power transfer switch of claim 9 , wherein the third and fourth mechanical switches are configured as a single-pole double-throw switch.
11 . The dual power transfer switch of claim 1 , wherein the power supply unit comprises: a first AC to DC converter configured to convert the AC electrical power selectively received from the first power supply to DC electrical power; a second AC to DC converter configured to convert the AC electrical power selectively received from the second power supply to DC electrical power; and a three-phase inverter unit configured to receive the DC electrical power from the first and second AC to DC converters and to generate therefrom the AC electrical power of the controlled phase.
12 . The dual power transfer switch of claim 1 , wherein the first solid-state switch has three bridge arms, each configured to receive a corresponding phase of three-phase AC electrical power of the first phase provided by the first power supply, the second solid-state switch has three bridge arms, each configured to receive a corresponding phase of three-phase AC electrical power of the second phase provided by the second power supply, and the power supply unit is a three-phase power supply unit configured to generate three-phase AC electrical power of the controlled phase.
13 . The dual power transfer switch of claim 12 , wherein the power supply unit comprises: an AC to DC converter configured to convert the AC electrical power selectively received from the first or second power supplies to DC electrical power; and a three-phase inverter unit configured to receive the DC electrical power from the AC to DC converter and to generate therefrom the AC electrical power of the controlled phase.
14 . The dual power transfer switch of claim 13 , wherein the AC to DC converter comprises a high-frequency transformer.
15 . The dual power transfer switch of claim 13 , wherein the AC to DC converter comprises a power frequency transformer.
16 . The dual power transfer switch of claim 1 , wherein each of the first and second solid-state switches comprises a bidirectional switch array, wherein the bidirectional switch array is formed through a thyristor, a metal oxide semiconductor field effect transistor (MOSFET), or an insulated gate bipolar transistor (IGBT).
17 . The dual power transfer switch of claim 16 , wherein the bidirectional switch array comprises a reverse parallel pair of thyristors, or MOSFETs, or IGBT transistors.
18 . The dual power transfer switch of claim 1 , wherein the controller is further configured, in response to detecting the failure of the first power supply, to: cause the power supply unit to provide the AC electrical power of the first phase to the load before causing the first solid-state switch to open, thereby temporarily providing the AC electrical power of the first phase to the load from both the first power supply and the power supply unit.

Description

CROSS REFERENCE TO RELATED APPLICATIONS The present application is a 35 U.S.C. § 371 National Phase Application of International PCT Patent Application No. PCT/CN2023/105027, filed Jun. 30, 2023, which claims the benefit of priority of Chinese Patent Application No. CN 202210770934.8, filed on Jun. 30, 2022. The entire contents of these applications are incorporated herein by reference in their entirety. TECHNICAL FIELD The present disclosure relates to a dual power supply transfer, and more specifically, to a dual power supply transfer switch based on a solid-state switch. BACKGROUND At present, the dual power supply transfer scheme with uninterrupted load is an automatic transfer switch (ATS) and uninterruptible power supply (UPS) architecture. The ATS is a simple mechanical structure, subject to inherent drawbacks of the mechanical structure. And the traditional ATS switching time is often greater than 100 ms, which is often unacceptable for some devices sensitive to power-down time. Therefore, for such loads, (The) ATS cannot independently complete power supply switching and often needs to cooperate with the UPS to meet the demand for supplying power to the load uninterruptedly. Specifically, the ATS is connected to two power supplies to switch between them, and when it is switching, supplying power to the load during the short-time switching power-down process is maintained by cooperating with the UPS. SUMMARY Technical Problem Based on the ATS and UPS architecture, continuous supplying power to the load side can be implemented, but there are the following drawbacks. Since the ATS switching process results in a power-down on the UPS input side, and the power-down duration may be up to 500 ms. In addition, the ATS uses mechanical switch (CTR) to switch power supply output, so when the power supply is switching, the CTR may experience arcing phenomenon. In addition, the ATS and UPS architectures cannot track a phase difference between the two power supplies. On the other hand, maintaining supplying power to the load side requires an internal battery pack of the UPS. For loads above 100 A, a larger battery pack is required. At the same time, in order to maintain the continuity of supplying power to the load, the modules of the UPS must be online for a long period of time, which results in a relatively low power transfer efficiency. Solution to Problem According to one aspect of the present disclosure, a dual power supply transfer switch (SSATS) for switching between a first power supply (S1) and a second power supply (S2) to supply power to a load is provided, including: a solid-state switch (SS), through which the S1 or the S2 is connected to the load; and a compensation power supply module (AUX), through which the S1 or the S2 is connected to the load. The S2 is used to supply power to the load through the compensation power supply module in the case that the S1 fails in supplying power to the load. The S1 is turned off from the power supply side through the SS in a case where an output current or output voltage of the AUX satisfies a first condition, and in a case where a phase of the AUX satisfies the second condition, the S2 is used to supply power to the load through the SS, and the AUX stops supplying power to the load. In some embodiments, the SS includes: a first SS, which is connected to the S1 for connecting the S1 switch to the load; and a second SS, which is connected to the S2 for connecting the S2 switch to the load. In some embodiments, the SS is a single SS. In some embodiments, the SSATS includes: a first mechanical switch (CTR1), wherein the S1 is connected to the load through the CTR1 and the first SS; a second mechanical switch (CTR2), wherein the S2 is connected to the load through the CTR2 and the second SS. The CTR1 is turned off and the CTR2 is turned on, after the S1 is turned off from the power supply side through the SS. In some embodiments, the SSATS includes a fifth mechanical switch (CTR1/2), configured as a single-pole, double-throw switch and through which the S1 or the S2 is connected to a load. The S2 is connected to the load through the CTR1/2, after the S1 is turned off from the power supply side through the SS. In some embodiments, the SS includes a bidirectional switch array, wherein the bidirectional switch array is formed through a thyristor, an insulated gate bipolar transistor (IGBT) or a metal oxide semiconductor field effect transistor (MOSFET). In some embodiments, the bidirectional switch array includes a thyristor in reverse parallel, or a MOSFET or IGBT transistor in reverse series. In some embodiments, the AUX includes an AC-DC converter (AC/DC) and a three-phase inverter unit (VSI) in series. In some embodiments, the AC/DC includes: a first AC/DC connected between the S1 and the VSI; and a second AC/DC connected between the S2 and the VSI, wherein, the first AC/DC and the second AC/DC are connected in parallel to the VSI. In some embodiments, the AUX incl