Short-circuit mitigation device

Patent metadata

Field	Value
Publication number	US-2022200263-A1
Application number	US-202017606253-A
Country	US
Kind code	A1
Filing date	Apr 24, 2020
Priority date	Apr 24, 2019
Publication date	Jun 23, 2022
Grant date	—

Abstract

A short-circuit mitigation device for use in an electrolytic cell ( 101 ) is disclosed. The device comprises a switch ( 302 ) connected in parallel with a damping load ( 502 ). The switch is disposed between a contact ( 102 ) and an electrode ( 106 ) of the cell ( 101 ) to selectively provide an electrical conduction path between the contact and the electrode. The switch comprises a plurality of metal-oxide-semiconductor field-effect transistors (MOSFETs) ( 402 ) connected in parallel. The device further comprises a switch controller ( 306 ) operably associated with the switch ( 302 ) to monitor electric current ( 308 ) through the switch and to generate a toggle signal ( 309 ) to toggle the switch ( 302 ) from a conductive closed state to a non-conductive open state when the electric current exceeds a first threshold value.

First claim

1 . A short-circuit mitigation device for use in an electrolytic cell having an electrical contact and an electrode, the device comprising:
a switch connected in parallel with a damping load and disposed between the contact and the electrode, the switch configured to selectively provide an electrical conduction path between the contact and the electrode, wherein the switch comprises a plurality of metal-oxide-semiconductor field-effect transistors (MOSFETs) connected in parallel; a conductive failsafe path connected in parallel with the MOSFETs to provide an electrical path around the switch; and a switch controller operably associated with the switch to monitor electric current through the switch and to generate a toggle signal to toggle the switch from a conductive closed state to a non-conductive open state when the electric current exceeds a first threshold value.

2 . The device of claim 1 wherein the failsafe path includes a conductor having an electrical resistance greater than the electrical resistance of the plurality of MOSFETS in its closed conducting state.

3 . The device of claim 1 wherein the controller is further configured to operate in at least a first mode of operation and a second mode of operation wherein the first mode of operation has a first threshold value and the second mode of operation has a second threshold value.

4 . The device according to claim 1 wherein the controller is configured to generate the toggle signal when the electric current through the switch exceeds the first or second threshold value for a predetermined period of time.

5 . The device according to claim 1 wherein the controller is configured to transmit data indicative of the electric current.

6 . The device according to claim 1 wherein the controller is configured to transmit state data indicative of the state of the switch.

7 . The device according to claim 1 wherein the controller is configured to adopt a mode of operation in response to a received configuration signal.

8 . The device according to claim 7 wherein the configuration signal is state data received from a second controller of a second device according to claim 6 .

9 . The device according to claim 7 wherein the configuration signal is received from a cell controller.

10 . The device according to claim 9 wherein the cell controller is in two way communication with a plurality of controllers and generates the configuration signal in response to state data respectively received from each of the plurality of controllers.

11 . The device according to claim 1 wherein the controller is configured to adopt a low power state at predetermined times such that in the low power state the controller does not monitor the electric current through the switch.

12 . The device according to claim 1 wherein the controller is configured to generate a reset signal to toggle the switch from the non-conductive open state to the conductive closed state.

13 . The device according to claim 1 wherein the controller is configured to control the time averaged current through the switch.

14 . The device according to claim 13 wherein the controller is configured to control the time averaged current through the switch by cyclically generating a further signal to toggle the switch between the non-conductive open state for an open time period and the conductive closed state for a closed time period such that the time averaged current is determined by the relative open and closed time periods.

15 . The device on any of the preceding claims of claim 1 comprising:
a top contact to support the electrode;
a bottom contact to rest on the electrical contact and separated from the top contact by an electrically insulating layer;
wherein a first end of the switch electrically contacts the top contact and a second end of the switch electrically contacts the bottom contact and wherein the switch is displaced from the top and bottom contacts.

16 . The device according to claim 1 wherein the electrolytic cell is an electrowinning cell or an electrorefining cell or an electrodeposition cell.

17 . The device according to claim 1 wherein the first threshold current is a predetermined first multiple of a normal working current.

18 . The device according to claim 19 wherein the predetermined first multiple is from 1.5 to 3.

19 . The device according to claim 3 wherein second threshold current is a predetermined second multiple of a normal working current.

20 . The device according to claim 19 wherein the second multiple is from 2 to 3.5.

21 . A system comprising two or more devices according to claim 1 for mitigating a short-circuit in an electrolytic cell.

22 . A method performed by a short-circuit mitigation device having a switch connected in parallel with a conductive failsafe path to provide an electrical path around the switch, the switch comprising a plurality of metal-oxide-semiconductor field-effect transistors (MOSFETs) connected in parallel and disposed between an electrical contact and an electrode in an electrolytic cell, the method comprising:
receiving a current signal indicative of an electrical current through the switch; and generating a toggle signal to toggle the switch from a conductive closed state to a non-conductive open state when the current signal is indicative that the electric current exceeds a first or second threshold value.

Assignees

• Commw Scient Ind Res Org

Inventors

• Molenaar David
• Rajasingam Rueben
• Marcuson David
• Broadly Craig

Classifications

• H01H47/002

  Monitoring or fail-safe circuits · CPC title

• H03K17/0822

  in field-effect transistor switches · CPC title

• H03K17/122 Primary

  in field-effect transistor switches · CPC title

• H02H3/16 Primary

  responsive to fault current to earth, frame or mass (with balanced or differential arrangement H02H3/26 {; monitoring earth connection H02H5/105}) · CPC title

• H02H3/087

  for DC applications · CPC title