US-20260128244-A1 - DUAL ACTUATION FAST MECHANICAL SWITCH

Abstract

The exemplary systems, methods, and devices of the present disclosure include a dual actuation mechanical switch for a circuit breaker that includes a piezoelectric actuator that operates in conjunction with a second mechanical actuator, e.g., for a fast, compact, lightweight, and efficient DC hybrid circuit breaker. In some implementations, the exemplary dual mechanical switch can serve as the only current carrying path of the circuit breaker to minimize on-state power loss during normal operation. The exemplary system, method, and devices can facilitate needs of the emerging DC grid.

Inventors

• Alfonso J. CRUZ
• Ning Guo
• Lukas Graber
• Zhiyang JIN
• Yang Liu
• Maryam TOUSI

Assignees

• GEORGIA TECH RESEARCH CORPORATION

Dates

Publication Date

20260507

Application Date

20231020

Claims (20)

1. 1 . A system comprising: a first conductive structure electrically connected to a first electrical terminal to receive high current and high voltage; a first movable contact structure moveably connected to the first conductive structure and configured to move between a first position and a second position each in relation to the first conductive structure while in electrical contact with the first conductive structure; a second contact structure electrically connected to a second electrical terminal configured to handle high current and high voltage, wherein the first movable contact structure is in contact with the second contact structure when in the first position, and wherein the first movable contact structure is disconnected from the second contact structure when in the second position; a first actuation assembly disposed within the first conductive structure and mechanically coupled to the first movable contact structure to move the first movable contact structure, along a first direction, between the first position and the second position when energized or deenergized, respectively, to connect or disconnect the first movable contact structure to the second contact structure; and a second actuation assembly either (i) mechanically coupled to the first actuation assembly within the first conductive structure to concurrently move the first movable contact structure from the first position to the second position, or (ii) mechanically coupled to the second contact structure within a second conductive structure to concurrently move the second contact structure to a third position further away from the first movable contact structure.
2. 2 . The system of claim 1 , wherein the first actuation assembly moves the first movable contact structure to the first position when energized, and the first actuation assembly moves the first movable contact structure from the first position to the second position to break contact with the second contact structure when de-energized.
3. 3 . The system of claim 1 , wherein the second actuation assembly is disposed within the first conductive structure and is mechanically coupled to the first actuation assembly, wherein the second actuation assembly moves the first movable contact structure in part from the first position to the second position.
4. 4 . The system of claim 1 , wherein the second actuation assembly is disposed within the second conductive structure and moves the second contact structure to the third position, to further extend a separation distance between the first movable contact structure and the second contact structure.
5. 5 . The system of claim 4 , wherein the second actuation assembly moves the second contact structure in response to a thermal expansion to (i) ensure adequate electrical connection between the first and second contact structures in the first position, and (ii) ensure an adequate separation distance between the first and second contact structures in the second and third positions.
6. 6 . The system of claim 1 , wherein the first actuation assembly has a first longitudinal axis corresponding to the first direction, wherein the second actuation assembly has a second longitudinal axis colinear to the first longitudinal axis.
7. 7 . The system of claim 1 , wherein a separation distance between the first movable contact structure and the second contact structure provides insulation of at least 100 kV.
8. 8 . The system of claim 1 , further comprising: an outer housing that surrounds the first movable contact structure and the second contact structure, wherein the outer housing is an enclosed vessel to surround the first conductive structure, the first movable contact structure, and the second contact structure and enclose a dielectric fluid.
9. 9 . The system of claim 8 , wherein the outer housing comprises an insulative material.
10. 10 . The system of claim 8 , wherein the outer housing is a pressure vessel configured to house supercritical fluids as a dielectric medium.
11. 11 . The system of claim 3 , further comprising: a third actuation assembly located in the second conductive structure, the third actuation assembly coupled to the second contact structure.
12. 12 . The system of claim 1 , wherein the first and second contact structures together form an opposing piston arrangement.
13. 13 . The system of claim 1 , wherein the first actuation assembly comprises a plurality of piezoelectric devices arranged in at least one stack and, wherein the second actuation assembly comprises a servo motor, linear stepper motor, or a hydraulic system.
14. 14 . The system of claim 8 , further comprising: a heat exchange system comprising: a pipe disposed partially within the outer housing and partially outside of the outer housing via a heat exchanger opening defined by a sidewall of the outer housing; a heat exchanger disposed adjacent to the outer housing; and a pump in fluid communication with the pipe, the pump configured to move a control fluid through the pipe between the heat exchanger and the outer housing.
15. 15 . The system of claim 1 , wherein a signal to de-energize the first actuation assembly to move the first movable contact structure from the first position to the second position to break contact with the second contact structure is triggered by a 0V or near-zero voltage condition across the first and second contact structures.
16. 16 . The system of claim 1 , further comprising: a controller coupled to the first and second actuation assemblies and configured to de-energize the first actuation assembly to move the first movable contact structure from the first position to the second position to break contact with the second contact structure, wherein a signal for the controller to de-energize the first actuation assembly is triggered by a 0V or near-zero voltage condition across the first and second actuation assemblies.
17. 17 . The system of claim 16 , wherein the controller energizes or de-energizes each of the first actuation assembly and the second actuation assembly concurrently based on the signal.
18. 18 . The system of claim 1 , wherein the system is configured as an AC power circuit breaker or a DC power circuit breaker.
19. 19 . The system of claim 8 , wherein the outer housing comprises one or both of (i) welded seams and (ii) bolts extending through a side portion of the outer housing to seal a supercritical fluid within an inner cavity defined by the outer housing.
20. 20 . (canceled)

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Ser. No. 63/380,304 , filed Oct. 20, 2022, which is incorporated herein by reference in its entirety. STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT This invention was made with government support under Grant No. AWD-002133 awarded by the Advanced Research Projects Agency-Energy Department of Energy. The government has certain rights in the invention. TECHNICAL FIELD The present disclosure relates, generally, to electric power systems. More specifically, it relates to mechanical switches, e.g., transfer or disconnect switches, in a circuit breaker. BACKGROUND A transfer switch is an electrical component configured to transfer loads between electrical connections. Existing fast transfer switches have been developed based on Thomson coils, power electronics, propellant-based systems, or coupled electromechanical and hydraulic systems, each of the foregoing having some technical trade-offs. Thomson coils require high current pulses. Other components can employ power electronics switches that can have significant conduction losses. Yet other components may be propellant-based and thus cannot be automatically reset. Other hybrid electromechanical and hydraulic systems are complex and slow. For conventional disconnect switch applications where non-current-carrying electrical conductors are physically moved to achieve separation from each other, thus creating electrical isolation, coupled mechanical systems can be used to separate the contacts sufficiently so that the breakdown voltage of the contact gap is sufficient for the application. This contact separation can be conventionally achieved by an indirect application of force through a series of levers or via the direct application of force with the contacts, e.g., enclosed in a vacuum or pressurized gas medium (called the switching chamber), or via a combination of the two approaches. Trade-offs of these methods include the speed, particularly for fast and high voltage applications, e.g., medium voltage (1 kV-69 kV) switching applications. Such types of disconnect switches are being considered for hybrid power electronics. Furthermore, large, slow circuit breakers are typically used to handle high-magnitude fault currents in a system. There is a benefit to improving disconnect/transfer switches. SUMMARY The exemplary systems, methods, and devices of the present disclosure include a dual actuation mechanical switch for a circuit breaker that includes a piezoelectric actuator that operates in conjunction with a second mechanical actuator, e.g., for a fast, compact, lightweight, and efficient DC hybrid circuit breaker. In some implementations, the exemplary dual mechanical switch can serve as the only current-carrying path of the circuit breaker to minimize on-state power loss during normal operation. The exemplary system, method, and devices can facilitate the needs of the emerging DC grid. During an example normal operation, the piezoelectric actuator and second mechanical actuator (e.g., stepper motor) are energized to make contact and effectively close a circuit, allowing current flow, and, during an example tripping event, the piezoelectric actuator and the second mechanical actuator operates simultaneously to break the connection. The piezoelectric actuator can respond within several hundreds of a microsecond, while, at the same time, the second mechanical actuator (e.g., stepper motor) can enlarge the gap distance between the two contact plates, effectively increasing the basic impulse level to more than 100 kV within 1 to 2 seconds, as observed in certain configurations. The ultrafast disconnect/transfer operation can be made straightforward (with few moving components) and compact while operating without high energy requirements or loss. The system can automatically reset to provide effective control. In some implementations, the exemplary systems, methods, and devices are implemented in a high-pressure vessel to improve the material's coefficient of thermal expansion for elevated temperature operation. The pressure vessel can retain supercritical fluids (SCF) as a dielectric medium that can enhance voltage breakdown capabilities while also being able to carry several kiloamperes of continuous current. In one aspect, a system is disclosed, the system including: a first conductive structure (e.g., piezoelectric device housing) electrically connected to a first electrical terminal to receive high current and high voltage. The system further includes a first movable contact structure moveably connected to the first conductive structure and configured to move between a first position and a second position each in relation to the first conductive structure while in electrical contact with the first conductive structure. The system further includes a second contact structure (e.g., stationary or movable) electrically connected to a second electrical ter