CN113650503B

CN113650503B - High-voltage interlocking electrical protection system, protection method and electric locomotive

Info

Publication number: CN113650503B
Application number: CN202111134676.6A
Authority: CN
Inventors: 王文; 王晓元; 张佳峰
Original assignee: CRRC Datong Co Ltd
Current assignee: CRRC Datong Co Ltd
Priority date: 2021-09-27
Filing date: 2021-09-27
Publication date: 2023-02-03
Anticipated expiration: 2041-09-27
Also published as: CN113650503A

Abstract

The disclosure relates to the technical field of electric locomotives and discloses a high-voltage interlocking electrical protection system, a protection method and an electric locomotive. This high voltage interlocking electrical protection system uses a plurality of locomotives of reconnection, electrical protection system includes: the protection branch circuits are arranged corresponding to the locomotives and comprise a first switch and a pantograph electromagnetic valve which are connected in series, and the protection branch circuits are connected with a set voltage after being connected in series; wherein the first switch is configured to be open when the locomotive is in a service state and closed when the locomotive is in a non-service state; the pantograph solenoid valve is configured to control a corresponding pantograph to lower a pantograph when any one of the first switches is in an off state. According to the electric protection system provided by the disclosure, when the first switch of any locomotive is in an off state, the pantograph electromagnetic valve is powered off, so that the corresponding pantograph cannot lift, the electric interlocking among a plurality of locomotives is realized, and the running safety of the electric locomotive is effectively improved.

Description

High-voltage interlocking electrical protection system, protection method and electric locomotive

Technical Field

The disclosure relates to the technical field of electric locomotives, in particular to a high-voltage interlocking electrical protection system, a protection method and an electric locomotive.

Background

Electric locomotives are powered by 25kV catenary systems and therefore improper operation is subject to high voltage hazards. In order to ensure the safe operation of the electric locomotive and protect the personnel and locomotive equipment, corresponding electric interlocking protection measures must be taken to avoid the damage caused by the misoperation of a high-voltage device. In the prior art, a mechanical high-voltage interlocking scheme is usually adopted, namely, the interlocking protection of a blue key, a yellow key and a green key is adopted, and the three keys are extremely easy to obtain in the normal application process and cannot effectively play a role in protection.

It is to be noted that the information disclosed in the above background section is only for enhancement of understanding of the background of the present disclosure, and thus may include information that does not constitute prior art known to those of ordinary skill in the art.

Disclosure of Invention

The present disclosure aims to overcome the above-mentioned deficiencies in the prior art, and provides a high-voltage interlock electrical protection system, a protection method and an electric locomotive.

According to one aspect of the present disclosure, there is provided a high voltage interlock electrical protection system for use with multiple locomotives coupled together, the electrical protection system comprising:

the protection branch circuits are arranged corresponding to the locomotives and comprise a first switch and a pantograph electromagnetic valve which are connected in series, and the protection branch circuits are connected with a set voltage after being connected in series;

wherein the first switch is configured to open when the locomotive is in a service state and to close when the locomotive is in a non-service state;

the pantograph solenoid valve is configured to control a corresponding pantograph to lower a pantograph when any one of the first switches is in an off state.

In an exemplary embodiment of the present disclosure, the protection branch further comprises a second switch in series with the first switch and the pantograph solenoid valve, the second switch configured to open when the locomotive is in a service condition and to close when the locomotive is in a non-service condition;

the pantograph solenoid valve is further configured to control a corresponding pantograph to pantograph down when any one of the second switches is in an off state.

In an exemplary embodiment of the present disclosure, the protection branch further comprises:

a pantograph-ascending relay in series with the first switch, the second switch and the pantograph solenoid valve, the pantograph-ascending relay configured to be in a power-off state in response to a power-off control signal to open the protection branch.

In an exemplary embodiment of the present disclosure, the electrical protection system further includes:

the controller comprises an input end and an output end, the output end is connected with the control end of the pantograph-rising relay, the input end is connected with the second switch and the first switch, and the controller is used for collecting a state signal of the first switch and a state signal of the second switch and outputting a corresponding control signal according to the state signal.

In an exemplary embodiment of the present disclosure, the controller is further configured to: the method comprises the steps of collecting a level signal of a first switch and a level signal of a second switch, and outputting a power-off control signal to a pantograph lifting relay when the level signal of the first switch is a low level and/or the level signal of the second switch is a low level, wherein the power-off control signal is used for controlling the pantograph lifting relay to lose power.

In an exemplary embodiment of the disclosure, the first switch is a high-voltage grounding switch of the locomotive, and an auxiliary contact of the high-voltage grounding switch is connected in series with the protection branch;

the second switch is a high-voltage isolating switch of the locomotive, and an auxiliary contact of the high-voltage isolating switch is connected in series with the protection branch circuit;

wherein the high voltage grounding switch comprises a main contact and an auxiliary contact, and the auxiliary contact acts in response to the main contact;

the high voltage isolation switch comprises a main contact and an auxiliary contact, and the auxiliary contact acts in response to the main contact.

In an exemplary embodiment of the present disclosure, the controller is a train control and management system, TCMS, of the locomotive;

the set voltage is 110V.

According to a second aspect of the present disclosure, there is also provided a high-voltage interlock electrical protection method applied to an electrical protection system according to any embodiment of the present disclosure, the method being performed by a controller, the method including:

detecting a level signal of the first switch and a level signal of the second switch in real time;

and controlling the pantograph-lifting relay to be powered on or powered off according to the level signal.

In an exemplary embodiment of the present disclosure, the controlling the pantograph relay to be powered on or powered off according to the level signal includes:

and if any first switch is in a high level and/or any second switch is in a low level, controlling the pantograph lifting relay to lose power.

According to a third aspect of the present disclosure, there is also provided an electric locomotive comprising the high-voltage interlocking electrical protection system according to any embodiment of the present disclosure.

The electric protection system comprises a plurality of protection branches, each protection branch corresponds to one locomotive, a plurality of protection branches are connected in series and then connected with a set voltage to form a series loop among the locomotives, when a first switch of any locomotive is in a disconnection state, a pantograph electromagnetic valve is powered off, so that a corresponding pantograph cannot be lifted, electric interlocking among the locomotives is realized, therefore, when the locomotive is in a maintenance state, even if a high-voltage device of the locomotive is triggered by mistake to execute a power-on operation, because the pantograph electromagnetic valve is in a power-off state, the pantograph cannot be lifted, the locomotive cannot be powered on, safety accidents caused by high-voltage components of any misoperation locomotive can be avoided, and the running safety of the electric locomotive is effectively improved.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and together with the description, serve to explain the principles of the disclosure. It is to be understood that the drawings in the following description are merely exemplary of the disclosure, and that other drawings may be derived from those drawings by one of ordinary skill in the art without the exercise of inventive faculty.

FIG. 1 is a schematic structural diagram of a high-voltage interlocking electrical protection system of an electric locomotive according to the present disclosure;

FIG. 2 is a schematic diagram of a high voltage power receiving portion of an electric locomotive according to the present disclosure;

fig. 3 is a flow chart of the electrical protection method of the present disclosure.

Detailed Description

Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and thus their detailed description will be omitted. Furthermore, the drawings are merely schematic illustrations of the present disclosure and are not necessarily drawn to scale.

Although relative terms, such as "upper" and "lower," may be used herein to describe one element of an icon relative to another, such terms are used herein for convenience only, e.g., with reference to the orientation of the example illustrated in the drawings. It will be understood that if the illustrated device is turned upside down, elements described as "upper" will be those that are "lower". When a structure is "on" another structure, it may mean that the structure is integrally formed with the other structure, or that the structure is "directly" disposed on the other structure, or that the structure is "indirectly" disposed on the other structure via another structure.

The terms "a", "an", "the", "said" and "at least one" are used to indicate the presence of one or more elements/components/parts/etc.; the terms "comprising" and "having" are intended to be inclusive and mean that there may be additional elements/components/etc. other than the listed elements/components/etc.; the terms "first," "second," and "third," etc. are used merely as labels, and are not limiting on the number of their objects.

The embodiment of the present disclosure provides an electric locomotive high-voltage interlocking electrical protection system, which is applied to multiple locomotives in a reconnection, and as shown in fig. 1, a schematic structural diagram of the electric locomotive high-voltage interlocking electrical protection system is shown, it should be understood that fig. 1 only shows a schematic diagram of the electrical protection system when two locomotives are in a reconnection, and the electrical protection system provided by the present exemplary embodiment is not limited to a reconnection of two locomotives. Referring to fig. 1, the electrical protection system includes: the protection system comprises a plurality of protection branches 10 corresponding to a plurality of locomotives, wherein each protection branch 10 comprises a first switch 120 and a pantograph electromagnetic valve 140 which are connected in series, and the plurality of protection branches 10 are connected with a set voltage after being connected in series; wherein the first switch 120 is configured to be open when the locomotive is in a service state and closed when the locomotive is in a non-service state; the pantograph solenoid valve 140 is configured to control a corresponding pantograph to lower the pantograph when any one of the first switches 120 is in an off state.

The electrical protection system provided by the exemplary embodiment includes a plurality of protection branches 10, each protection branch 10 corresponds to a locomotive, a set voltage is connected after the plurality of protection branches 10 are connected in series, a series circuit is formed among the plurality of locomotives, when the first switch 120 of any locomotive is in an off state, the pantograph electromagnetic valve 140 is de-energized, so that the corresponding pantograph cannot be raised, and electrical interlocking among the plurality of locomotives is realized.

As shown in fig. 1, in the exemplary embodiment, the first switch 120 of the protection branch 10 in the same locomotive is connected in series with the pantograph solenoid valve 140, and the plurality of protection branches 10 of a plurality of locomotives are also connected in series, so that the first switch 120 of any locomotive is electrically interlocked with the first switch 120 of the adjacent locomotive, and thus when the first switch 120 of any locomotive is disconnected, the pantograph solenoid valve 140 of the multi-locomotive is powered off, and thus the pantograph of each locomotive cannot be raised. Correspondingly, in a practical situation, when the locomotive normally operates, the first switch 120 is in a closed state, so that the pantograph electromagnetic valve 140 is powered on and can be in a pantograph lifting state; when the locomotive is overhauled, the first switch 120 is in an off state, and the pantograph electromagnetic valve 140 loses power and cannot lift the pantograph, so that even if the high-voltage device of the locomotive is powered on at the moment, the pantograph cannot lift due to misoperation because the pantograph electromagnetic valve 140 loses power, safety accidents caused by misoperation can be avoided, and the safety of personnel can be effectively ensured. It should be understood that the pantograph solenoid valve 140 in the present exemplary embodiment is a low-pressure control device of the pantograph. According to the embodiment, the high-voltage interlocking electrical protection of the electric locomotive is realized by building the pantograph lifting low-voltage control loop, so that the operation safety of the electric locomotive is improved, and the safety of locomotive equipment and personal safety can be guaranteed. Further, it should be understood that the locomotive is also required to be electrically protected from high voltage interlock while the locomotive is in service, and thus the first switch 120 and the pantograph solenoid valve 140 have the same operating conditions as when the locomotive is in service.

In addition, it should be understood that the first switch 120 may be a switch member provided on the electric locomotive itself, or may be an additional switch member. In an alternative embodiment of the present disclosure, the first switch 120 is a high-voltage grounding switch of the electric locomotive, and the configuration of the high-voltage grounding switch can be referred to in the description of the following embodiments.

In this exemplary embodiment, each protection branch 10 may be connected to a voltage of 110V after being connected in series, and of course, in other exemplary embodiments, the set voltage connected to the electrical protection system may be other voltages.

As shown in fig. 1, in the exemplary embodiment, each protection branch 10 may further include a second switch 110, the second switch 110 being connected in series with the first switch 120 and the pantograph solenoid valve 140, the second switch 110 being configured to be open when the locomotive is in the service state and to be closed when the locomotive is in the non-service state, and accordingly, the pantograph solenoid valve is further configured to control the corresponding pantograph lowering when any one of the second switches is in the open state. The first switch 120, the second switch 110 and the pantograph solenoid valve 140 in the protection branch 10 of the same locomotive are connected in series, and the protection branches 10 of a plurality of locomotives are also connected in series, so that the first switch 120 of any locomotive is connected with the second switch 110 and the first switch 120 of the adjacent locomotive to realize electrical interlocking, and thus when the first switch 120 or the second switch 110 of any locomotive is disconnected, each pantograph solenoid valve 140 of the multiple locomotives is powered off, and thus the pantograph of each locomotive cannot be lifted. Correspondingly, in a practical situation, when the locomotive normally operates, the first switch 120 and the second switch 110 are in a closed state, so that the pantograph electromagnetic valve 140 is powered on and can be in a pantograph-lifting state; when the locomotive is overhauled, the first switch 120 and the second switch 110 are both in an off state, and the pantograph electromagnetic valve 140 loses power and cannot lift the pantograph, so that even if the locomotive is controlled to be powered on by misoperation of personnel, the pantograph cannot lift due to misoperation because the pantograph electromagnetic valve 140 loses power, safety accidents caused by misoperation can be avoided, and the safety of the personnel can be effectively ensured. It should be appreciated that in the exemplary embodiment, the locomotive is also required to be electrically protected from high voltage interlock while the locomotive is in service, and therefore the second switch 110 and the pantograph solenoid valve 140 have the same operating conditions as when the locomotive is in service. In addition, it should be understood that the second switch 110 may be a switch of the electric locomotive itself, or may be an additional switch. In an alternative embodiment of the present disclosure, the second switch 110 is a high-voltage isolation switch of the electric locomotive, and the configuration of the high-voltage isolation switch can be referred to in the description of the following embodiments. Further, it should be understood that, in the present exemplary embodiment, the order of connection of the first switch 120, the second switch 110, and the pantograph solenoid valve 140 is not limited.

Fig. 2 is a schematic diagram of a high-voltage power receiving part of an electric locomotive, and high-voltage equipment components of the high-voltage double-heading electric locomotive comprise: pantograph, high-voltage earthing switch 50, high-voltage isolating switch 60, etc. The pantograph obtains 25kV from the catenary, and the main breaker 30 supplies power to the electric locomotive traction transformer 40 and the like after being closed. Before locomotive maintenance and overhaul, the high-voltage grounding switch 50 shown in fig. 2 needs to be closed (which is equivalent to the closing of the main contact of the high-voltage grounding switch 50 and the main circuit), so that the main circuit breaker 30 is short-circuited, and the pantograph cannot rise to form electrical protection. If one of the two electric locomotives fails, the failed electric locomotive can be isolated by isolating the high-voltage isolating switch 60 shown in fig. 2, so that the continuous operation of the electric locomotive is ensured. Because the high-voltage isolating switch 60 and the high-voltage grounding switch 50 both comprise a main contact and an auxiliary contact, wherein the main contact is arranged in a main power supply loop of the locomotive and is used for controlling the main power supply loop of the locomotive, and the main contact and the auxiliary contact have a linkage effect, namely when the main contact is closed, the auxiliary contact is also closed, and when the main contact is opened, the auxiliary contact is also opened; alternatively, the auxiliary contacts are open when the main contacts are closed and closed when the main contacts are open. Thus, the auxiliary contacts of the high voltage grounding switch 50 and the auxiliary contacts of the high voltage isolation switch 60 of the locomotive may be utilized to construct a pantograph high voltage control loop. For example, the first switch 120 may be a high-voltage grounding switch 50 of a locomotive, an auxiliary contact of the high-voltage grounding switch 50 is connected in series with the protection branch 10, and the auxiliary contact of the high-voltage grounding switch 50 acts in response to the main contact. The second switch 110 may be a high voltage isolation switch 60 of the locomotive, an auxiliary contact of the high voltage isolation switch 60 is connected in series to the protection branch 10, and the auxiliary contact of the high voltage isolation switch 60 acts in response to the main contact. For example, the high voltage grounding switch 50 may be configured such that when the main contact is closed, the auxiliary contact is open, and when the main contact is open, the auxiliary contact is closed. Likewise, the high voltage isolation switch 60 may be configured such that when the main contacts are closed, the auxiliary contacts are also closed, and when the main contacts are open, the auxiliary contacts are also open. When the locomotive is in an overhauling or maintenance state, the main contact of the high-voltage grounding switch 50 of the locomotive connected with the main circuit is closed, correspondingly, the auxiliary contact of the high-voltage grounding switch 50 is in an off state, and the auxiliary contact of the high-voltage grounding switch 50 is connected in series with the protection branch 10, so that the protection branch 10 is in an open circuit, and further, the pantograph electromagnetic valve 140 loses power, so that the pantograph cannot rise, and safety accidents caused by misoperation of high-voltage components can be avoided. In the exemplary embodiment, as shown in fig. 1, the auxiliary contacts of the high-voltage isolation switches 60 of the locomotives are connected in series into the protection branch 10, so that the high-voltage grounding switch 50 of any locomotive is connected with the high-voltage grounding switch 50 and the high-voltage isolation switch 60 of the adjacent locomotive to realize electrical interlocking, when any locomotive has a fault, the high-voltage isolation switch 60 can be disconnected from the fault locomotive, and meanwhile, the protection branch 10 is disconnected because the high-voltage isolation switch 60 is disconnected, so that the failure of pantograph of the fault locomotive and the non-fault locomotive can be controlled, and the safety of the electric locomotive can be further improved. In addition, it should be noted that, unless otherwise specified, the first switch 120 in the present exemplary embodiment is a high-voltage grounding switch, and the second switch 110 is a high-voltage isolating switch.

As shown in fig. 1, in the present exemplary embodiment, the protection branch circuit 10 may further include a pantograph relay 130, the pantograph relay 130 being connected in series with the first switch 120, the second switch 110 and the pantograph solenoid valve 140, the pantograph relay 130 being configured to be in a power-off state in response to the power-off control signal so as to open the protection branch circuit 10. Because the pantograph-ascending relay 130 is connected in series with the pantograph electromagnetic valve 140, when the pantograph-ascending relay 130 loses power, the pantograph-ascending relay 130 is in a disconnection state to break the series branch, so that the pantograph electromagnetic valve 140 loses power, and the analysis shows that when the pantograph electromagnetic valve 140 loses power, the pantograph cannot ascend, so that when the locomotive is in an overhaul or maintenance state, the pantograph-ascending relay 130 can be actively controlled in real time by detecting whether the key position of each locomotive is in an abnormal state or not in real time, and then the locomotive can be actively controlled not to be connected with a catenary when the locomotive is detected to be in the abnormal state, so that the locomotive is prevented from being electrified abnormally. The power failure control signal can be generated by detecting key components of the electric locomotive through the controller. For example, a controller may be arranged to detect the state of the high-voltage grounding switch and/or the high-voltage isolating switch in real time, and when the high-voltage grounding switch and/or the high-voltage isolating switch is detected to be in a set state (for example, an off state), the controller may control the pantograph-lifting relay 130 to lose power so as to cause the pantograph electromagnetic valve 140 to lose power, so that the locomotive is controlled not to be connected with a catenary when the locomotive is abnormal, thereby ensuring personnel safety.

As shown in fig. 1, in the present exemplary embodiment, the electrical protection system may further include a controller (not shown), an output terminal of the controller is connected to the control terminal of the pantograph ascending relay 130, and an input terminal of the controller is connected to the second switch 110 and the first switch 120, so that the controller may collect the level signal of the first switch 120 and the level signal of the second switch 110 in real time, and may output a power-off control signal capable of powering off the pantograph ascending relay 130 according to the level signal of the second switch 110 and the level signal of the first switch 120. Illustratively, the controller may be a train control and management system, TCMS, of the locomotive. The TCMS of the locomotive detects the real-time state of the first switch 120 and the real-time state of the second switch 110 of each locomotive in real time, when the locomotive is overhauled or maintained, the first switch 120 and the second switch 110 of the locomotive are usually controlled to be in an off state, when the TCMS detects that the first switch 120 of any locomotive is in a low level or any second switch 110 of any locomotive is in a low level, the TCMS outputs a power-off control signal to the pantograph-ascending relay 130 in real time to control the pantograph-ascending relay 130 to be powered off, so that the pantograph electromagnetic valve 140 is further powered off, each double locomotive cannot be electrified to be connected, even if a high-voltage device of the locomotive in overhauling or maintenance is operated by mistake, the contact network cannot be powered on, and therefore safety accidents caused by misoperation can be avoided.

The pantograph lifting relay 130 is arranged, the pantograph lifting relay 130 is controlled by the TCMS of the locomotive in real time according to the states of the second switch 110 and the first switch 120 of the locomotive, so that the condition that the pantograph lifting of the locomotive is electrified due to false triggering when the locomotive is in a maintenance state is ensured, and meanwhile, when the locomotive is in the maintenance state, because the first switch 120 and the second switch 110 are electrically interlocked with adjacent locomotives on hardware, the safety control of the locomotive is realized from two aspects of software and hardware, the operation safety of an electric locomotive is improved, and the equipment and personal safety of the locomotive are ensured.

In addition, the present disclosure also provides a high-voltage interlocking electrical protection method, which may be applied to the electrical protection system described in any of the above embodiments, and is executed by a controller, and fig. 3 is a flowchart of the electrical protection method, and the method may include the following steps:

s110, detecting a level signal of the first switch and a level signal of the second switch in real time;

and S120, controlling the pantograph lifting relay to be powered on or powered off according to the level signal.

As described in the above embodiments, the first switch may be a high-voltage grounding switch of the locomotive, the second switch may be a high-voltage isolating switch of the locomotive, and the auxiliary contact of the high-voltage grounding switch and the auxiliary contact of the high-voltage isolating switch are connected in series to the protection branch. The controller detects the level signal of the first switch, namely the controller detects the level signal of the auxiliary contact of the high-voltage grounding switch, and similarly, the controller detects the level signal of the second switch, namely the controller detects the level signal of the auxiliary contact of the high-voltage isolating switch.

In step S110, the controller detects whether the locomotive is in a normal operation state or a maintenance state by acquiring a level signal of the auxiliary contact of the high-voltage grounding switch and a level signal of the auxiliary contact of the high-voltage isolating switch in real time. For example, when the controller detects that the auxiliary contact of the high-voltage grounding switch is at a low level, the controller may determine that the locomotive is in a repair or maintenance state at the moment; conversely, if the controller detects that the auxiliary contact of the high-voltage grounding switch is at a high level, the controller may determine that the locomotive is in a normal operation state.

In step S120, the controller controls the pantograph relay and further controls the pantograph solenoid valve according to the state of the high-voltage grounding switch and the state of the high-voltage isolating switch. Specifically, when the controller detects that the auxiliary contact of the high-voltage grounding switch of any locomotive is at a low level or detects that the auxiliary contact of the high-voltage isolating switch of any locomotive is at a low level, the controller determines that the locomotive is in an overhauling or maintenance state at the moment, the controller outputs a power-off control signal to the pantograph-ascending relay to control the pantograph-ascending relay to lose power, and the pantograph-ascending relay and the pantograph electromagnetic valve are connected in series with the protection branch circuit, so that the protection branch circuit is broken when the pantograph-ascending relay loses power, the pantograph electromagnetic valve loses power and the pantograph cannot ascend.

The electrical protection method provided by the exemplary embodiment forms redundant control with the electrical protection system described in any of the above embodiments, and can improve the safety of the electric locomotive in operation.

In addition, the locomotive comprises the electric protection system according to any embodiment, and therefore the locomotive provided by the invention also comprises the beneficial effects described in any embodiment.

It should be noted that although the steps of the high voltage interlock electrical protection method of the present disclosure are depicted in the drawings in a particular order, this does not require or imply that the steps must be performed in this particular order or that all of the depicted steps must be performed to achieve desirable results. Additionally or alternatively, certain steps may be omitted, multiple steps combined into one step execution, and/or one step broken into multiple step executions, etc.

Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. This application is intended to cover any variations, uses, or adaptations of the disclosure following, in general, the principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.

Claims

1. A high voltage interlocking electrical protection system employing multiple locomotives in a reconnection, said electrical protection system comprising:

the protection branch circuits are arranged corresponding to the locomotives and comprise a first switch and a pantograph electromagnetic valve which are connected in series, and the protection branch circuits are connected with a set voltage after being connected in series; wherein the first switch is configured to be open when the locomotive is in a service state and closed when the locomotive is in a non-service state; the pantograph electromagnetic valve is configured to control a corresponding pantograph to bow when any one of the first switches is in an off state;

the protection branch further comprises:

a second switch in series with the first switch and the pantograph solenoid valve, the second switch configured to open when the locomotive is in a service state and to close when the locomotive is in a non-service state; the pantograph electromagnetic valve is also configured to control the corresponding pantograph to bow when any one of the second switches is in an off state;

a pantograph-raising relay connected in series with the first switch, the second switch and the pantograph solenoid valve, the pantograph-raising relay being configured to be in a power-off state in response to a power-off control signal to cause the protection branch to be opened;

the electrical protection system further comprises:

2. The electrical protection system of claim 1, wherein the controller is further configured to: the method comprises the steps of collecting a level signal of a first switch and a level signal of a second switch, and outputting a power-off control signal to a pantograph lifting relay when the level signal of the first switch is a low level and/or the level signal of the second switch is a low level, wherein the power-off control signal is used for controlling the pantograph lifting relay to lose power.

3. The electrical protection system of claim 1, wherein the first switch is a high voltage ground switch of the locomotive, and an auxiliary contact of the high voltage ground switch is connected in series to the protection branch;

the high-voltage grounding switch comprises a main contact and an auxiliary contact, and the auxiliary contact acts in response to the main contact;

4. The electrical protection system of claim 1, wherein said controller is a Train Control and Management System (TCMS) of said locomotive;

the set voltage is 110V.

5. A high-voltage interlocking electrical protection method applied to the electrical protection system of any one of claims 1 to 4, wherein the method is executed by a controller, and the method comprises the following steps:

6. The method of claim 5, wherein controlling the pantograph relay to be energized or de-energized in accordance with the level signal comprises:

7. An electric locomotive comprising a high voltage interlocking electrical protection system as claimed in any one of claims 1 to 4.