Multi-net-rack fault simulation device

Abstract

The utility model provides a multi-net-rack fault simulation device, which comprises a three-phase feeder power supply, an outlet circuit breaker module, a ring main unit module, an interval switch module, a pole-mounted switch module, an interconnection switch and a plurality of fault simulation modules, the outlet circuit breaker module is respectively connected with the pole-mounted switch module and the interval switch module through cables, and fault access points are arranged between switches in the interval switch module, between switches in the pole-mounted switch module, between the interval switch module and the outlet circuit breaker module and between the pole-mounted switch module and the outlet circuit breaker module. And each fault access point is electrically connected with the fault simulation module through an independent fault control switch to realize feeder automation fault simulation. According to the utility model, simulation training and verification can be carried out on simulation fault processing at different positions for distribution network multi-net-frame multi-mode feeder automation.

Description

Technical Field

[0001] The utility model belongs to the technical field of power distribution network, in particular to a multi-grid fault simulation device. Background Art

[0002] With the continuous advancement of distribution automation construction, FA has been favored by power supply companies and has been fully developed due to its functional characteristics such as reducing the scope of power outages, shortening power outage time and improving power supply reliability. However, the application of its core function feeder automation in a large number of distribution automation projects currently implemented is not ideal, has not played its due value, and has a low degree of practicality. In addition, there is a lack of corresponding simulation devices for distribution network faults, and it cannot effectively simulate different fault conditions of the distribution network, which is not conducive to a good response to distribution network faults. Utility Model Content

[0003] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a multi-grid fault simulation device to solve the problem that the prior art cannot accurately simulate different faults of distribution network racks.

[0004] To achieve the above-mentioned purpose and other related purposes, the utility model provides a multi-grid fault simulation device, including a three-phase feeder power supply, an outlet circuit breaker module, a ring network cabinet module, an interval switch module, a pole switch module, a connecting switch and a plurality of fault simulation modules, wherein the ring network cabinet module includes a plurality of ring network cabinets, and the interval switch module includes a plurality of interval switches. The feeder power supply is electrically connected to the outlet circuit breaker module, and the outlet circuit breaker module is electrically connected to the pole switch module and the interval switch module respectively. The interval switch module is electrically connected to the ring network cabinet module and the pole switch module respectively. The connecting switch is connected between switches in the pole switch module, and fault access points are provided between switches inside the interval switch module, between switches inside the pole switch module, between the interval switch module and the outlet circuit breaker module, and between the pole switch module and the outlet circuit breaker module. Each of the fault access points is electrically connected to the fault simulation module through an independent fault control switch.

[0005] Among them, the fault simulation module includes an incoming line control switch unit, a transition resistance unit and an outgoing line switch unit, one end of the incoming line control switch unit is electrically connected to the three-phase cable in the line, and the other end of the incoming line control switch unit is electrically connected to the transition resistance unit and the outgoing line switch unit respectively.

[0006] In one embodiment of the utility model, the incoming line control switch unit includes a first incoming line control switch, a second incoming line control switch and a third incoming line control switch, the outgoing line switch unit includes a first outgoing line switch, a second outgoing line switch, a third outgoing line switch and a fourth outgoing line switch, the transition resistance unit includes a fixed resistor and a variable resistor connected in series, one end of the first incoming line control switch, one end of the second incoming line control switch and one end of the third incoming line control switch are respectively connected to one phase of the three-phase cable, the other end of the first incoming line control switch is electrically connected to one end of the first outgoing line switch, one end of the third outgoing line switch and one end of the fourth outgoing line switch, the other end of the second incoming line control switch is electrically connected to the other end of the first outgoing line switch, the other end of the fourth outgoing line switch and one end of the second outgoing line switch, the other end of the third incoming line control switch is electrically connected to the other end of the second outgoing line switch and one end of the fixed resistor, the other end of the fixed resistor is electrically connected to one end of the variable resistor, the other end of the variable resistor is electrically connected to one end of the third outgoing line switch, and the other end of the third outgoing line switch is grounded.

[0007] In one embodiment of the utility model, the export circuit breaker module includes four substation export circuit breakers simulated by AC contactors, namely, the first export circuit breaker, the second export circuit breaker, the third export circuit breaker, and the fourth export circuit breaker. The ring network cabinet module includes the first ring network cabinet, the second ring network cabinet, and the third ring network cabinet. The interval switch module includes the first interval switch, the second interval switch, the third interval switch, the fourth interval switch, the fifth interval switch, the sixth interval switch, the seventh interval switch, and the eighth interval switch. The pole switch module includes the first pole switch, the second pole switch, the third pole switch, the fourth pole switch, the fifth pole switch, the sixth pole switch, the seventh pole switch, the eighth pole switch, and the ninth pole switch. switch, the tenth pole switch, the eleventh pole switch and the twelfth pole switch, one end of the first outlet circuit breaker, one end of the second outlet circuit breaker, one end of the third outlet circuit breaker and one end of the fourth outlet circuit breaker are all electrically connected to the feeder power supply, one end of the first interval switch and one end of the second interval switch are all electrically connected to the first ring network cabinet, one end of the third interval switch, one end of the fourth interval switch and one end of the fifth interval switch are all electrically connected to the second ring network cabinet, one end of the sixth interval switch, one end of the seventh interval switch and one end of the eighth interval switch are all electrically connected to the third ring network cabinet, the other end of the first outlet circuit breaker is connected to the other end of the first interval switch, the second between the other end of the interval switch and the other end of the third interval switch, between the other end of the fifth interval switch and the other end of the sixth interval switch, between the other end of the second outlet circuit breaker and one end of the first pole switch, between the other end of the first pole switch and one end of the second pole switch, between the other end of the second pole switch and one end of the third pole switch, between the other end of the third pole switch and one end of the fourth pole switch, between the other end of the third outlet circuit breaker and one end of the fifth pole switch, between the other end of the fifth pole switch and one end of the sixth pole switch, between the other end of the sixth pole switch and one end of the seventh pole switch, between the other end of the seventh pole switch and the eighth pole switch The fault control switch is provided between one end of the fourth pole switch, between the other end of the fourth outlet circuit breaker and one end of the ninth pole switch, between the other end of the ninth pole switch and one end of the tenth pole switch, between the other end of the tenth pole switch and one end of the eleventh pole switch, between the other end of the eleventh pole switch and one end of the twelfth pole switch, and between the other end of the fourth pole switch and the other end of the eighth pole switch, so as to access the fault simulation module through the fault control switch, one end of the connecting switch is connected between the other end of the sixth pole switch and one end of the seventh pole switch, and the other end of the connecting switch is connected between the other end of the tenth pole switch and one end of the eleventh pole switch.

[0008] In one embodiment of the present invention, an interlocking mechanism is provided between a plurality of different fault control switches, so that only one fault control switch can be closed at the same time.

[0009] In an embodiment of the present invention, each of the fault control switches is electrically connected to a fault controller so as to control each of the fault control switches through the fault control.

[0010] As described above, the multi-grid fault simulation device described in the utility model has the following beneficial effects:

[0011] Different faults are simulated through the fault simulation module, and the fault simulation module is respectively connected to the fault access points between the switches inside the interval switch module, between the switches inside the pole switch module, between the interval switch module and the outlet circuit breaker module, and between the pole switch module and the outlet circuit breaker module, so that faults at different positions of the entire power grid line can be simulated through the fault simulation module, which can meet the fault simulation requirements of different requirements and is conducive to fault simulation testing and training. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 Shown is a structural block diagram of the multi-grid fault simulation device of the utility model.

[0013] Figure 2 Shown is a circuit diagram of the multi-grid fault simulation device of the utility model.

[0014] Figure 3 Shown is a connection diagram of a fault simulation module and a fault control switch in a multi-grid fault simulation device of the present invention.

[0015] Figure 4 Shown is a circuit diagram of a fault simulation module in the multi-grid fault simulation device of the utility model. DETAILED DESCRIPTION

[0016] The following describes the implementation of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific implementations, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0017] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and thus the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed at will, and the component layout may also be more complicated.

[0018] The multi-grid fault simulation device of the utility model simulates different faults through a fault simulation module, and simultaneously connects the fault simulation module to the fault access points between switches inside the interval switch module, between switches inside the pole switch module, between the interval switch module and the outlet circuit breaker module, and between the pole switch module and the outlet circuit breaker module, thereby facilitating the simulation of faults at different positions of the entire power grid line through the fault simulation module, which can meet fault simulations of different requirements and is conducive to fault simulation testing and training.

[0019] like Figures 1 to 4 As shown, in one embodiment, a multi-grid fault simulation device of the utility model includes a three-phase feeder power supply 1, an export circuit breaker module 2, a ring network cabinet module 3, a spacer switch module 4, a pole switch module 5, a contact switch 6 and a plurality of fault simulation modules 7, wherein the ring network cabinet module 3 includes a plurality of ring network cabinets, and the spacer switch module 4 includes a plurality of spacer switches. The feeder power supply 1 is electrically connected to the export circuit breaker module 2, and the export circuit breaker module 2 is electrically connected to the pole switch module 5 and the spacer switch module 4 respectively, and the spacer switch module 4 is electrically connected to the ring network cabinet module 3 and the pole switch module 5 respectively, and the contact switch 6 is connected between a plurality of switches in the pole switch module 5, and a fault access point is provided between the switches inside the spacer switch module 4, between the switches inside the pole switch module 5, between the spacer switch module 4 and the export circuit breaker module 2, and between the pole switch module 5 and the export circuit breaker module 20, and each of the fault access points is electrically connected to the fault simulation module 7 through an independent fault control switch 8;

[0020] Among them, the fault simulation module 7 includes an incoming line control switch unit 71, a transition resistor unit 72 and an outgoing line switch unit 73, one end of the incoming line control switch unit 71 is electrically connected to the three-phase cable in the line, and the other end of the incoming line control switch unit 71 is electrically connected to the transition resistor unit 72 and the outgoing line switch unit 73 respectively.

[0021] In this embodiment, by connecting the fault simulation module 7 to each fault access point, fault simulation can be performed at fault access points in different locations through the fault simulation module 7, thereby simulating different fault scenarios and facilitating simulation training of different faults for the distribution network.

[0022] In some embodiments, the incoming line control switch unit 71 includes a first incoming line control switch 711, a second incoming line control switch 712, and a third incoming line control switch 713, the outgoing line switch unit 73 includes a first outgoing line switch 731, a second outgoing line switch 732, a third outgoing line switch 733, and a fourth outgoing line switch 734, the transition resistance unit 72 includes a fixed resistor 721 and a variable resistor 722 connected in series, one end of the first incoming line control switch 711, one end of the second incoming line control switch 712, and one end of the third incoming line control switch 713 are respectively connected to one phase of the three-phase cable, and the other end of the first incoming line control switch 711 is connected to the first One end of the outgoing line switch 731, one end of the third outgoing line switch 73, and one end of the fourth outgoing line switch 734 are electrically connected, the other end of the second incoming line control switch 712 is electrically connected to the other end of the first outgoing line switch 731, the other end of the fourth outgoing line switch 734, and one end of the second outgoing line switch 732, respectively, the other end of the third incoming line control switch 713 is electrically connected to the other end of the second outgoing line switch 732 and one end of the fixed resistor 721, the other end of the fixed resistor 721 is electrically connected to one end of the variable resistor 722, the other end of the variable resistor 722 is electrically connected to one end of the third outgoing line switch 733, and the other end of the third outgoing line switch 733 is grounded. The outlet circuit breaker module 2 includes four substation outlet circuit breakers simulated by AC contactors, namely, a first outlet circuit breaker 21, a second outlet circuit breaker 22, a third outlet circuit breaker 23, and a fourth outlet circuit breaker 24. The ring network cabinet module 3 includes a first ring network cabinet 31, a second ring network cabinet 32, and a third ring network cabinet 33. The interval switch module 4 includes a first interval switch 41, a second interval switch 42, a third interval switch 43, a fourth interval switch 44, a fifth interval switch 45, a sixth interval switch 46, a seventh interval switch 47, and an eighth interval switch 48. The pole switch module 8 includes a first pole switch 501, a second pole switch 502, a third pole switch 503, a fourth pole switch 504, a The fifth pole switch 505, the sixth pole switch 506, the seventh pole switch 507, the eighth pole switch 508, the ninth pole switch 509, the tenth pole switch 510, the eleventh pole switch 511 and the twelfth pole switch 510, one end of the first outlet circuit breaker 21, one end of the second outlet circuit breaker 22, one end of the third outlet circuit breaker 23, and one end of the fourth outlet circuit breaker 24 are all electrically connected to the feeder power supply 1, one end of the first interval switch 41 and one end of the second interval switch 42 are all electrically connected to the first ring network cabinet 31, one end of the third interval switch 43, one end of the fourth interval switch 44, and one end of the fifth interval switch 45 are all electrically connected to the second ring network cabinet 32,One end of the sixth interval switch 46, one end of the seventh interval switch 47 and one end of the eighth interval switch 48 are all electrically connected to the third ring main unit 33, between the other end of the first outlet circuit breaker 21 and the other end of the first interval switch 41, between the other end of the second interval switch 42 and the other end of the third interval switch 43, between the other end of the fifth interval switch 45 and the other end of the sixth interval switch 46, between the other end of the second outlet circuit breaker 22 and one end of the first pole switch 501, between the other end of the first pole switch 501 and one end of the second pole switch 502, between the other end of the second pole switch 502 and one end of the third pole switch 503, between the other end of the third pole switch 503 and one end of the fourth pole switch 504, between the other end of the third outlet circuit breaker 23 and one end of the fifth pole switch 505, between the other end of the fifth pole switch 505 and one end of the sixth pole switch 506, and between the sixth pole switch The fault control switch 8 is provided between the other end of the sixth pole switch 506 and one end of the seventh pole switch 507, between the other end of the seventh pole switch 507 and one end of the eighth pole switch 508, between the other end of the fourth outlet circuit breaker 24 and one end of the ninth pole switch 509, between the other end of the ninth pole switch 509 and one end of the tenth pole switch 510, between the other end of the tenth pole switch 510 and one end of the eleventh pole switch 511, between the other end of the eleventh pole switch 511 and one end of the twelfth pole switch 512, between the other end of the fourth pole switch 504 and the other end of the eighth pole switch 508, so as to access the fault simulation module 7 through the fault control switch 8, one end of the contact switch 6 is connected between the other end of the sixth pole switch 506 and one end of the seventh pole switch 507, and the other end of the contact switch 6 is connected between the other end of the tenth pole switch 510 and one end of the eleventh pole switch 511.

[0023] In this embodiment, taking the three-phase cables of the feeder power supply 1 as an example, the AC contactors corresponding to the switches in the above-mentioned lines can be controlled by the multi-mode distribution terminal for electrical data collection and opening and closing, which is consistent with the actual operating environment of the distribution terminal. At the same time, the fault access points between the switches are connected to the fault control switch 8, and are centrally connected to the fault simulation module 7 to realize the control of the fault location, so that each fault access point can realize the simulation of single-phase grounding fault and two-phase short circuit fault. The fault phase can be set, that is, the A-phase single-phase grounding fault, the B-phase single-phase grounding fault, the C-phase single-phase grounding fault, the AB two-phase short circuit fault, the BC two-phase short circuit fault, and the AC two-phase short circuit fault can be realized, which is convenient for simulating different fault conditions.

[0024] Specifically, the specific simulation process of the fault simulation module 7 is described below. When simulating the AB two-phase short-circuit fault, the third incoming line control switch 713, the first outgoing line switch 731, the third outgoing line switch 733 and the fourth outgoing line switch 734 are disconnected, and the first incoming line control switch 711, the second incoming line control switch 712, and the second outgoing line switch 732 are closed; when simulating the AC two-phase short-circuit fault, the second incoming line control switch 712, the first outgoing line switch 731, the third outgoing line switch 733 and the fourth outgoing line switch 734 are disconnected, and the first incoming line control switch 711, the third incoming line control switch 713, and the second outgoing line switch 732 are closed; when simulating the BC two-phase short-circuit fault, the first incoming line control switch 711, the first outgoing line switch 731, the second outgoing line switch 732, and the third outgoing line switch 733 are disconnected, and the second incoming line control switch 712, the third incoming line control switch 713, and the fourth outgoing line control switch 734 are closed. When simulating a single-phase grounding fault of phase A, the second incoming line control switch 712, the third incoming line control switch 713 and the fourth outgoing line switch 734 are disconnected, and the first incoming line control switch 711, the first outgoing line switch 731, the second outgoing line switch 732 and the third outgoing line switch 733 are closed; when simulating a single-phase grounding fault of phase B, the first incoming line control switch 711, the third incoming line control switch 713 and the fourth outgoing line switch 734 are disconnected, and the second incoming line control switch 712, the first outgoing line switch 731, the second outgoing line switch 732 and the third outgoing line switch 733 are closed; when simulating a single-phase grounding fault of phase C, the first incoming line control switch 711, the second incoming line control switch 712 and the fourth outgoing line switch 734 are disconnected, and the third incoming line control switch 713, the first outgoing line switch 731, the second outgoing line switch 732 and the third outgoing line switch 733 are closed, which will not be repeated here.

[0025] It should be noted that, since the transition resistance unit 72 has a built-in fixed resistor 721 and a variable resistor 722, the transition resistance unit 72 can be adjusted within a certain range to achieve flexible adjustment of the short-circuit fault current, zero-sequence voltage, and zero-sequence current.

[0026] In some other embodiments, an interlocking mechanism is set between multiple different fault control switches 8, and only one fault control switch 8 can be closed at the same time, so that the fault control switch 8 can only connect one fault access point to the fault simulation module 7 at a time, ensuring that the fault simulation will not be interfered by other faults, thereby ensuring the accuracy of the fault simulation.

[0027] In some other embodiments, each of the fault control switches 8 is electrically connected to a fault controller so as to control each of the fault control switches 8 through the fault control, thereby enabling the fault location, fault type, fault phase, fault transition resistance, fault duration, etc. to be flexibly set remotely.

[0028] It should be noted that the fault controller adopts a controller in the prior art, and its specific control process is the content of the prior art. This solution does not involve any improvement to it itself, and it will not be repeated here.

[0029] In summary, the multi-grid fault simulation device of the utility model simulates different faults through the fault simulation module, and at the same time, the fault simulation module is respectively connected to the fault access points between the switches inside the interval switch module, between the switches inside the pole switch module, between the interval switch module and the outlet circuit breaker module, and between the pole switch module and the outlet circuit breaker module, so that it is convenient to simulate the faults at different positions of the entire power grid line through the fault simulation module, which can meet the fault simulation of different requirements and is conducive to fault simulation testing and training. Therefore, the utility model effectively overcomes the various shortcomings of the prior art and has a high industrial utilization value.

[0030] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the technology may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed in the present invention shall still be covered by the claims of the present invention.

Claims

1. A multi-grid fault simulation device, characterized in that: It includes a three-phase feeder power supply, an export circuit breaker module, a ring network cabinet module, an interval switch module, a pole switch module, a contact switch and multiple fault simulation modules, wherein the ring network cabinet module includes multiple ring network cabinets, the interval switch module includes multiple interval switches, the feeder power supply is electrically connected to the export circuit breaker module, the export circuit breaker module is respectively connected to the pole switch module and the interval switch module by cable, the interval switch module is connected to the ring network cabinet module by cable, the contact switch is connected between multiple switches of the pole switch module, fault access points are arranged between the interval switches, between switches inside the pole switch module, between the interval switch module and the export circuit breaker module, and between the pole switch module and the export circuit breaker module, and each of the fault access points is electrically connected to the fault simulation module through an independent fault control switch; Among them, the fault simulation module includes an incoming line control switch unit, a transition resistance unit and an outgoing line switch unit, one end of the incoming line control switch unit is electrically connected to the three-phase cable in the line, and the other end of the incoming line control switch unit is electrically connected to the transition resistance unit and the outgoing line switch unit respectively.

2. The multi-grid fault simulation device according to claim 1, characterized in that: The incoming line control switch unit includes a first incoming line control switch, a second incoming line control switch and a third incoming line control switch, the outgoing line switch unit includes a first outgoing line switch, a second outgoing line switch, a third outgoing line switch and a fourth outgoing line switch, the transition resistance unit includes a fixed resistor and a variable resistor connected in series, one end of the first incoming line control switch, one end of the second incoming line control switch and one end of the third incoming line control switch are respectively connected to one phase of the three-phase cable, the other end of the first incoming line control switch is electrically connected to one end of the first outgoing line switch, one end of the third outgoing line switch and one end of the fourth outgoing line switch, the other end of the second incoming line control switch is electrically connected to the other end of the first outgoing line switch, the other end of the fourth outgoing line switch and one end of the second outgoing line switch, the other end of the third incoming line control switch is electrically connected to the other end of the second outgoing line switch and one end of the fixed resistor, the other end of the fixed resistor is electrically connected to one end of the variable resistor, the other end of the variable resistor is electrically connected to one end of the third outgoing line switch, and the other end of the third outgoing line switch is grounded.

3. The multi-grid fault simulation device according to claim 2, characterized in that: The export circuit breaker module includes four substation export circuit breakers simulated by AC contactors, namely, the first export circuit breaker, the second export circuit breaker, the third export circuit breaker, and the fourth export circuit breaker; the ring network cabinet module includes the first ring network cabinet, the second ring network cabinet, and the third ring network cabinet; the interval switch module includes the first interval switch, the second interval switch, the third interval switch, the fourth interval switch, the fifth interval switch, the sixth interval switch, the seventh interval switch, and the eighth interval switch; the pole switch module includes the first pole switch, the second pole switch, the third pole switch, the fourth pole switch, the fifth pole switch, the sixth pole switch, the seventh pole switch, the eighth pole switch, the ninth pole switch, and the tenth pole switch , the eleventh pole switch and the twelfth pole switch, one end of the first outlet circuit breaker, one end of the second outlet circuit breaker, one end of the third outlet circuit breaker, and one end of the fourth outlet circuit breaker are all electrically connected to the feeder power supply, one end of the first interval switch and one end of the second interval switch are all electrically connected to the first ring network cabinet, one end of the third interval switch, one end of the fourth interval switch, and one end of the fifth interval switch are all electrically connected to the second ring network cabinet, one end of the sixth interval switch, one end of the seventh interval switch, and one end of the eighth interval switch are all electrically connected to the third ring network cabinet, the other end of the first outlet circuit breaker is connected to the other end of the first interval switch, and the other end of the second interval switch is electrically connected to the third ring network cabinet. between the other end of the third interval switch, between the other end of the fifth interval switch and the other end of the sixth interval switch, between the other end of the second outlet circuit breaker and one end of the first pole switch, between the other end of the first pole switch and one end of the second pole switch, between the other end of the second pole switch and one end of the third pole switch, between the other end of the third pole switch and one end of the fourth pole switch, between the other end of the third outlet circuit breaker and one end of the fifth pole switch, between the other end of the fifth pole switch and one end of the sixth pole switch, between the other end of the sixth pole switch and one end of the seventh pole switch, between the other end of the seventh pole switch and one end of the eighth pole switch The fault control switch is provided between the other end of the fourth pole switch, between the other end of the fourth output circuit breaker and one end of the ninth pole switch, between the other end of the ninth pole switch and one end of the tenth pole switch, between the other end of the tenth pole switch and one end of the eleventh pole switch, between the other end of the eleventh pole switch and one end of the twelfth pole switch, and between the other end of the fourth pole switch and the other end of the eighth pole switch to access the fault simulation module through the fault control switch, one end of the connecting switch is connected between the other end of the sixth pole switch and one end of the seventh pole switch, and the other end of the connecting switch is connected between the other end of the tenth pole switch and one end of the eleventh pole switch.

4. The multi-grid fault simulation device according to claim 3, characterized in that: An interlocking mechanism is provided between the multiple different fault control switches, and only one fault control switch can be closed at the same time.

5. The multi-grid fault simulation device according to claim 4, characterized in that: Each of the fault control switches is electrically connected to a fault controller so that each of the fault control switches is controlled by the fault control.

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