US-12627147-B2 - Integrated switched capacitor bank with zero close control

Abstract

A switched capacitor bank system including a switched capacitor bank assembly having a switch between a capacitor and a phase line, a first voltage sensor to sense a phase line voltage, and a second voltage sensor to sense a capacitor voltage. The switched capacitor bank system includes a wireless current sensor to sense a current of the phase line and an electronic controller configured to receive a first voltage signal from the first voltage sensor, a second voltage signal from the second voltage sensor, a current signal from the wireless current sensor, determine a phase shift calculation for the voltage of the phase line based on the current signal, determine when the voltage of the phase line is at zero by comparing the first voltage signal, the second voltage signal, and the phase shift calculation, and close the switch when the voltage of the phase line is at zero.

Inventors

• Balaji Santhanam
• Juliene Britt
• David S. Yaney

Assignees

• ACLARA TECHNOLOGIES LLC

Dates

Publication Date

20260512

Application Date

20241009

Claims (20)

1. 1 . A switched capacitor bank system comprising: a switched capacitor bank assembly including a first capacitor; a first switch selectively connected between the first capacitor and a first phase line; a first voltage sensor integrated within a housing of the first switch and configured to sense a voltage of the first phase line; a second voltage sensor integrated within the housing of the first switch and configured to sense a voltage of the first capacitor; a frame arranged to physically support the first capacitor, the first switch, the first voltage sensor, and the second voltage sensor; a first wireless current sensor attached to the first phase line and configured to sense a current of the first phase line; and an electronic controller including an electronic processor, the electronic controller operably coupled to the first switch, the first voltage sensor, the second voltage sensor, the first wireless current sensor, and configured to: receive a first voltage signal indicative of the voltage of the first phase line from the first voltage sensor; receive a second voltage signal indicative of the voltage of the first capacitor from the second voltage sensor; receive a first current signal indicative of the current of the first phase line from the first wireless current sensor; determine a first phase shift calculation for the voltage of the first phase line based on the first current signal; determine when the voltage of the first phase line is at zero by comparing the first voltage signal, the second voltage signal, and the first phase shift calculation; and close the first switch when the voltage of the first phase line is at zero.
2. 2 . The switched capacitor bank system of claim 1 , wherein the frame includes an arrester mounting portion.
3. 3 . The switched capacitor bank system of claim 1 , wherein the frame is mounted to a distribution pole.
4. 4 . The switched capacitor bank system of claim 1 , further comprising: a second capacitor physically supported by the frame; a second switch selectively connected between the second capacitor and a second phase line, the second switch being physically supported by the frame; a third voltage sensor integrated within a housing of the second switch and configured to sense a voltage of the second phase line; a fourth voltage sensor integrated within the housing of the second switch and configured to sense a voltage of the second capacitor; and a second wireless current sensor attached to the second phase line and configured to sense a current of the second phase line, wherein the electronic controller is operably coupled to the second switch, the third voltage sensor, the fourth voltage sensor, and the second wireless current sensor.
5. 5 . The switched capacitor bank system of claim 4 , wherein the electronic controller is further configured to: receive a third voltage signal indicative of the voltage of the second phase line from the third voltage sensor; receive a fourth voltage signal indicative of the voltage of the second capacitor from the fourth voltage sensor; receive a second current signal indicative of the current of the second phase line from the second wireless current sensor; determine a second phase shift calculation for the voltage of the second phase line based on the second current signal; determine when the voltage of the second phase line is at zero by comparing the third voltage signal, the fourth voltage signal, and the second phase shift calculation; and close the second switch when the voltage of the second phase line is at zero.
6. 6 . The switched capacitor bank system of claim 5 , further comprising: a third capacitor physically supported by the frame; a third switch selectively connected between the third capacitor and a third phase line, the third switch being physically supported by the frame; a fifth voltage sensor integrated within a housing of the third switch and configured to sense a voltage of the third phase line; a sixth voltage sensor integrated within the housing of the third switch and configured to sense a voltage of the third capacitor; and a third wireless current sensor attached to the third phase line and configured to sense a current of the third phase line, wherein the electronic controller is operably coupled to the third switch, the fifth voltage sensor, the sixth voltage sensor, and the third wireless current sensor.
7. 7 . The switched capacitor bank system of claim 6 , wherein the electronic controller is further configured to: receive a fifth voltage signal indicative of the voltage of the third phase line from the fifth voltage sensor; receive a sixth voltage signal indicative of the voltage of the third capacitor from the sixth voltage sensor; receive a third current signal indicative of the current of the third phase line from the third wireless current sensor; determine a third phase shift calculation for the voltage of the third phase line based on the third current signal; determine when the voltage of the third phase line is at zero by comparing the fifth voltage signal, the sixth voltage signal, and the third phase shift calculation; and close the third switch when the voltage of the third phase line is at zero.
8. 8 . The switched capacitor bank system of claim 7 , wherein the first current signal includes a phase and a magnitude of the current of the first phase line, the second current signal includes a phase and a magnitude of the current of the second phase line, and the third current signal includes a phase and a magnitude of the current of the third phase line.
9. 9 . The switched capacitor bank system of claim 1 , wherein the electronic controller is further configured to: determine a time period between previous first switch closing operations and closing the first switch; compare the time period to previous time periods for previous first switch closing operations; and determine a time delay for closing the first switch at subsequent closing operations.
10. 10 . A method for controlling a switched capacitor bank system, the switched capacitor bank system including a switched capacitor bank assembly having a first capacitor, a first switch selectively connected between the first capacitor and a first phase line, a first voltage sensor integrated within a housing of the first switch and configured to sense a voltage of the first phase line, a second voltage sensor integrated within the housing of the first switch and configured to sense a voltage of the first capacitor, and a frame arranged to physically support the first capacitor, the first switch, the first voltage sensor, and the second voltage sensor, the switched capacitor bank system also including a first wireless current sensor attached to the first phase line and configured to sense a current of the first phase line and an electronic controller including an electronic processor, the electronic controller operably coupled to the first switch, the first voltage sensor, the second voltage sensor, the first wireless current sensor, the method comprising: receiving, via the electronic controller, a first voltage signal indicative of the voltage of the first phase line from the first voltage sensor; receiving, via the electronic controller, a second voltage signal indicative of the voltage of the first capacitor from the second voltage sensor; receiving, via the electronic controller, a first current signal indicative of the current of the first phase line from the first wireless current sensor; determining, via the electronic controller, a first phase shift calculation for the voltage of the first phase line based on the first current signal; determining, via the electronic controller, when the voltage of the first phase line is at zero by comparing the first voltage signal, the second voltage signal, and the first phase shift calculation; and transmitting, via the electronic controller, a command to close the first switch when the voltage of the first phase line is at zero.
11. 11 . The method of claim 10 , the switched capacitor bank system further comprising: a second capacitor physically supported by the frame; a second switch selectively connected between the second capacitor and a second phase line, the second switch being physically supported by the frame; a third voltage sensor integrated within a housing of the second switch and configured to sense a voltage of the second phase line; a fourth voltage sensor integrated within the housing of the second switch and configured to sense a voltage of the second capacitor; and a second wireless current sensor attached to the second phase line and configured to sense a current of the second phase line, wherein the electronic controller is operably coupled to the second switch, the third voltage sensor, the fourth voltage sensor, and the second wireless current sensor.
12. 12 . The method of claim 11 , the method further comprising: receiving, via the electronic controller, a third voltage signal indicative of the voltage of the second phase line from the third voltage sensor; receiving, via the electronic controller, a fourth voltage signal indicative of the voltage of the second capacitor from the fourth voltage sensor; receiving, via the electronic controller, a second current signal indicative of the current of the second phase line from the second wireless current sensor; determining, via the electronic controller, a second phase shift calculation for the voltage of the second phase line based on the second current signal; determining, via the electronic controller, when the voltage of the second phase line is at zero by comparing the third voltage signal, the fourth voltage signal, and the second phase shift calculation; and transmitting, via the electronic controller, a command to close the second switch when the voltage of the second phase line is at zero.
13. 13 . The method of claim 12 , the switched capacitor bank system further comprising: a third capacitor physically supported by the frame; a third switch selectively connected between the third capacitor and a third phase line, the third switch being physically supported by the frame; a fifth voltage sensor integrated within a housing of the third switch and configured to sense a voltage of the third phase line; a sixth voltage sensor integrated within the housing of the third switch and configured to sense a voltage of the third capacitor; and a third wireless current sensor attached to the third phase line and configured to sense a current of the third phase line, wherein the electronic controller is operably coupled to the third switch, the fifth voltage sensor, the sixth voltage sensor, and the third wireless current sensor.
14. 14 . The method of claim 13 , the method further comprising: receiving, via the electronic controller, a fifth voltage signal indicative of the voltage of the third phase line from the fifth voltage sensor; receiving, via the electronic controller, a sixth voltage signal indicative of the voltage of the third capacitor from the sixth voltage sensor; receiving, via the electronic controller, a third current signal indicative of the current of the third phase line from the third wireless current sensor; determining, via the electronic controller, a third phase shift calculation for the voltage of the third phase line based on the third current signal; determining, via the electronic controller, when the voltage of the third phase line is at zero by comparing the fifth voltage signal, the sixth voltage signal, and the third phase shift calculation; and transmitting, via the electronic controller, a command to close the third switch when the voltage of the third phase line is at zero.
15. 15 . The method of claim 14 , wherein the first current signal includes a phase and a magnitude of the current of the first phase line, the second current signal includes a phase and a magnitude of the current of the second phase line, and the third current signal includes a phase and a magnitude of the current of the third phase line.
16. 16 . The method of claim 10 , the method further comprising: determining, via the electronic controller, a time period between previous first switch closing operations and closing the first switch; comparing, via the electronic controller, the time period to previous time periods for previous first switch closing operations; and determining, via the electronic controller, a time delay for closing the first switch at subsequent closing operations.
17. 17 . A switched capacitor bank system comprising: a plurality of phase lines including a first phase line, a second phase line, and a third phase line; a switched bank capacitor assembly including a plurality of capacitors including a first capacitor, a second capacitor, and a third capacitor; a plurality of voltage sensors including a first voltage sensor integrated within a housing of a first switch, the first voltage sensor configured to sense a voltage of the first phase line, a second voltage sensor integrated within the housing of the first switch, the second voltage sensor configured to sense a voltage of the first capacitor, a third voltage sensor configured to sense a voltage of the second phase line, a fourth voltage sensor configured to sense a voltage of the second capacitor, a fifth voltage sensor configured to sense a voltage of the third phase line, and a sixth voltage sensor configured to sense a voltage of the third capacitor; a plurality of switches including the first switch connected between the first phase line and the first capacitor, a second switch connected between the second phase line and the second capacitor, and a third switch connected between the third phase line and the third capacitor; a frame arranged to physically support the plurality of capacitors, the plurality of voltage sensors, and the plurality of switches; a plurality of wireless current sensors including a first wireless current sensor attached to the first phase line and configured to sense a current of the first phase line, a second wireless current sensor attached to the second phase line and configured to sense a current of the second phase line, and a third wireless current sensor attached to the third phase line and configured to sense a current of the third phase line; and an electronic controller including an electronic processor, the electronic controller operably coupled to the switched bank capacitor assembly and the plurality of wireless current sensors, the controller configured to selectively close the plurality of switches to connect the plurality of capacitors to the respective ones of the plurality of phase lines based on signals received from the plurality of voltage sensors and the plurality of wireless current sensors.
18. 18 . The switched capacitor bank system of claim 17 , wherein selectively closing the plurality of switches includes the electronic controller further configured to: receive a first voltage signal indicative of the voltage of the first phase line from the first voltage sensor; receive a second voltage signal indicative of the voltage of the first capacitor from the second voltage sensor; receive a first current signal indicative of the current of the first phase line from the first wireless current sensor; determine a first phase shift calculation for the voltage of the first phase line based on the first current signal; determine when the voltage of the first phase line is at zero by comparing the first voltage signal, the second voltage signal, and the first phase shift calculation; and close the first switch when the voltage of the first phase line is at zero.
19. 19 . The switched capacitor bank system of claim 18 , wherein selectively closing the plurality of switches includes the electronic controller further configured to: receive a third voltage signal indicative of the voltage of the second phase line from the third voltage sensor; receive a fourth voltage signal indicative of the voltage of the second capacitor from the fourth voltage sensor; receive a second current signal indicative of the current of the second phase line from the second wireless current sensor; determine a second phase shift calculation for the voltage of the second phase line based on the second current signal; determine when the voltage of the second phase line is at zero by comparing the third voltage signal, the fourth voltage signal, and the second phase shift calculation; and close the second switch when the voltage of the second phase line is at zero.
20. 20 . The switched capacitor bank system of claim 19 , wherein selectively closing the plurality of switches includes the electronic controller further configured to: receive a fifth voltage signal indicative of the voltage of the third phase line from the fifth voltage sensor; receive a sixth voltage signal indicative of the voltage of the third capacitor from the sixth voltage sensor; receive a third current signal indicative of the current of the third phase line from the third wireless current sensor; determine a third phase shift calculation for the voltage of the third phase line based on the third current signal; determine when the voltage of the third phase line is at zero by comparing the fifth voltage signal, the sixth voltage signal, and the third phase shift calculation; and close the third switch when the voltage of the third phase line is at zero.

Description

RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application No. 63/589,548, filed Oct. 11, 2023, the entire content of which is hereby incorporated by reference. FIELD Embodiments relate to capacitor bank switch assemblies. SUMMARY Switched capacitor banks may be installed on poles and/or at substations to apply power factor correction (e.g., by altering the load phasing) to the power grid in response to the application and removal of heavy industrial inductive loads. When loads are not in phase, additional reactive currents increase transmission losses, which may result in wasted energy and a need for additional generating capacity. Thus, capacitor banks are used to help improve the transfer efficiency of electrical energy being transmitted through the power grid. Charging and discharging of the capacitors is controlled with switches based on power factor correction needs of the grid. The charging and discharging of capacitors may be switched via the switches to optimize voltage and power flow to the power grid while reducing transmission losses. Given the complexity and variety of existing switched capacitor bank assembly configurations, complicated sensor and controller combinations are often utilized in an attempt to improve assembly performance. As a result, these assemblies may require long install times, may be difficult to troubleshoot, and may be expensive to maintain over the course of an assembly's lifespan. In addition, the sensing accuracy in existing capacitor bank assemblies may suffer due to magnitude and phase errors and signal interference caused by lengthy sensor and control cables included in the assembly. Thus, a solution that simplifies the complexity of the capacitor bank assembly, reduces installation time, and significantly reduces the troubleshooting and maintenance costs associated to capacitor banks over the life of the capacitor bank is desired. One aspect of the present disclosure provides a switched capacitor bank system including a switched capacitor bank assembly. The switched capacitor bank assembly further includes a first capacitor, a first switch selectively connected between the first capacitor and a first phase line, a first voltage sensor integrated within a housing of the first switch and configured to sense a voltage of the first phase line, a second voltage sensor integrated within the housing of the first switch and configured to sense a voltage of the first capacitor; a frame arranged to physically support the first capacitor, the first switch, the first voltage sensor, and the second voltage sensor, and a first wireless current sensor attached to the first phase line and configured to sense a current of the first phase line. The switched capacitor bank assembly further includes an electronic controller including an electronic processor, the electronic controller operably coupled to the first switch, the first voltage sensor, the second voltage sensor, the first wireless current sensor. The electronic controller is configured to receive a first voltage signal indicative of the voltage of the first phase line from the first voltage sensor, receive a second voltage signal indicative of the voltage of the first capacitor from the second voltage sensor, receive a first current signal indicative of the current of the first phase line from the first wireless current sensor and determine a first phase shift calculation for the voltage of the first phase line based on the first current signal. The electronic controller is further configured to determine when the voltage of the first phase line is at zero by comparing the first voltage signal, the second voltage signal, and the first phase shift calculation and close the first switch when the voltage of the first phase line is at zero. Another aspect of the present disclosure provides a method for controlling a switched capacitor bank system. The switched capacitor bank system includes a switched capacitor bank assembly having a first capacitor, a first switch selectively connected between the first capacitor and a first phase line, a first voltage sensor integrated within a housing of the first switch and configured to sense a voltage of the first phase line, a second voltage sensor integrated within the housing of the first switch and configured to sense a voltage of the first capacitor, and a frame arranged to physically support the first capacitor, the first switch, the first voltage sensor, and the second voltage sensor. The switched capacitor bank system also includes a first wireless current sensor attached to the first phase line and configured to sense a current of the first phase line and an electronic controller including an electronic processor, the electronic controller operably coupled to the first switch, the first voltage sensor, the second voltage sensor, the first wireless current sensor. The method includes receiving, via the electronic controller, a first voltage sig