Tramway switch control method and device

Abstract

The present invention discloses a method and device for controlling a tramway turnout, the method comprising: receiving a command for handling a route or single-operation turnout, and judging whether the turnout action condition is met; when the turnout action condition is met, driving the turnout action relay to be attracted, and driving the turnout protection relay to be attracted after a first preset time; collecting the turnout position state, judging whether the turnout has completed the position conversion according to the turnout position state, and stopping driving the turnout protection relay when the turnout has completed the position conversion, and stopping driving the turnout action relay after a first preset time. The present invention can realize the safe conversion of the turnout, ensure the safe operation of the train, and can extend the service life of the relay, and reduce the maintenance workload and maintenance cost of the switch machine.

Description

Technical Field

[0001] The present invention relates to the technical field of turnout control, and in particular to a method and device for controlling a turnout on a tramway. Background Art

[0002] In the field of tram signal technology, turnouts are one of the important trackside infrastructure equipment. By controlling the position conversion of turnouts, trains can be switched, in and out of the warehouse, and return. As a device that directly controls the position conversion of turnouts, the operation of the switch machine must be reliable and safe.

[0003] The existing switch control circuit generally controls the connection or disconnection of the switch control circuit in the following two ways:

[0004] (1) Only the AC contactor or the front contact of the gravity-type safety relay is used as the condition for connecting or disconnecting the control circuit. When the AC contactor or the front contact of the safety relay is closed, the control circuit is connected, the switch machine rotates and changes the turnout position; when the AC contactor or the front contact of the safety relay is disconnected, the control circuit is disconnected, the switch machine stops moving, and the turnout stops rotating, ensuring the safe passage of the train.

[0005] (2) The front contact of the gravity-type safety relay is used as the condition for connecting the switch machine control circuit, and the action of the switch motor contact row is used as the condition for disconnecting the switch machine control circuit. When the front contact of the gravity-type safety relay is closed, the control circuit is connected, the switch machine rotates and changes the switch position; after the switch is in place, when the switch motor contact row moves to disconnect from the original position, the switch machine control circuit is disconnected.

[0006] The existing tramway switch control method and device can realize normal switch switching when the safety relay or AC contactor works normally, but when encountering a complex on-site environment or an AC contactor failure, the following problems exist:

[0007] When using method (1): 1) Train derailment or overturning in the turnout area: AC contactors have no safety rating and are generally used in high-voltage control circuits such as electricity that do not have safety rating requirements. However, the safety rating requirements for tram turnout control circuits are relatively high. If only AC contactors are used to connect or disconnect the switch control circuit, when the AC contactor is sucked up for some reason and the front contact is mismatched, the switch control circuit will be connected, the switch will rotate incorrectly, and the turnout will be switched incorrectly, which may cause the train running in the turnout area to derail or overturn; 2) Personal injury at level crossings: When the turnout is in the intersection area of ​​trams and social traffic, when the AC contactor is sucked up for some reason and the front contact is mismatched, the switch control circuit will be connected, the switch will rotate incorrectly, and the turnout will be switched incorrectly, which may cause the train running in the turnout area to derail or overturn; 2) Personal injury at level crossings: When the turnout is in the intersection area of ​​trams and social traffic, when the AC contactor is sucked up for some reason and the front contact is mismatched, the switch control circuit will be connected, the turnout will rotate incorrectly, and the turnout will be switched incorrectly, which may cause the train running in the turnout area to derail or overturn. The switch machine rotates incorrectly, the turnout is switched incorrectly, and during the turnout changing process, pedestrians' feet may be pinched or even cut off by the switch, causing serious personal injury; 3) The train cannot pass through the turnout area: the gravity-type safety relay will not be mistakenly sucked up, but its front contacts have limited ability to withstand current shocks. Only the gravity-type safety relay is used to connect or disconnect the switch machine control circuit. When the distance between the switch machine and the turnout control cabinet is close, the switch machine power supply is closed or disconnected at the moment, and its control circuit will generate a strong induced current. When the strong current passes through the front contacts of the relay, the relay will arc, the contacts will burn and turn black, or even melt and be damaged, resulting in the turnout being unable to rotate again, affecting the normal passage, line change, and in and out of storage of trains.

[0008] When method (2) is adopted: 1) the switch machine control circuit uses a large number of relays and wiring, which takes up a large space, has a complex circuit, is difficult to construct and has many fault points, which is not conducive to later maintenance; 2) after the switch machine is in full motion, the strong induced current generated by its coil is borne by its moving contact row, causing the moving contact row to arc, burn and turn black, or even melt and be damaged, which affects its service life. Summary of the invention

[0009] The present invention aims to solve at least one of the technical problems in the related art to a certain extent. To this end, the first object of the present invention is to provide a tramway switch control method, which can achieve safe switch conversion, ensure safe operation of trains, extend the service life of relays, and reduce the maintenance workload and maintenance cost of switch machines.

[0010] A second object of the present invention is to provide a tramway switch control device.

[0011] To achieve the above object, the present invention is implemented through the following technical solutions:

[0012] A tramway switch control method, comprising:

[0013] Receive the command of route handling or single turnout operation, and judge whether the turnout action conditions are met;

[0014] When the turnout action condition is met, the turnout action relay is driven to be attracted, and after the first preset time, the turnout protection relay is driven to be attracted;

[0015] The switch position status is collected, and whether the switch has completed position conversion is determined according to the switch position status; when the switch has completed position conversion, the switch protection relay is stopped from being driven, and after the first preset time, the switch action relay is stopped from being driven.

[0016] Optionally, determining whether the switch action conditions are met includes: checking whether the switch section is in an idle state, and whether the switch section meets the conditions of not being locked by the route and not being locked individually.

[0017] Optionally, the method further includes: starting timing after the switch action relay is driven to be attracted, and stopping driving the switch protection relay when the timing duration exceeds a second preset time, wherein the second preset time is greater than the first preset time.

[0018] Optionally, the method also includes: when driving the switch protection relay to be attracted, collecting the rear contact state of the switch protection relay, so as to determine whether the switch protection relay is faulty according to the rear contact state of the switch protection relay, and issuing a fault alarm message when the switch protection relay fails.

[0019] Optionally, judging whether the switch protection relay is faulty is based on the state of the rear contact of the switch protection relay, including: during the process of driving the switch protection relay, if the state of the rear contact of the switch protection relay is always in a closed state, then judging that the switch protection relay is faulty.

[0020] To achieve the above object, the second aspect of the present invention provides a tramway switch control device, comprising:

[0021] A turnout action control module is used to receive a turnout handling or single turnout operation command, and output a turnout action relay drive command when the turnout action condition is met, and output a turnout protection relay drive command after the turnout action relay is driven for a first preset time;

[0022] A turnout action relay and a turnout protection relay drive interface, connected to the turnout action control module, the turnout action relay and the turnout protection relay drive interface are used to receive the turnout action relay drive command and the turnout protection relay drive command, and control the turnout action relay to be attracted and the turnout protection relay to be attracted;

[0023] A switch position and switch protection relay acquisition interface connected to the switch action control module, the switch position and switch protection relay acquisition interface is used to collect switch position information, so that the switch action control module outputs a switch protection relay stop driving command when determining that the switch has completed position conversion according to the switch position information, and outputs a switch action relay stop driving command after the first preset time;

[0024] The switch action relay and switch protection relay drive interface is also used to receive the switch protection relay stop drive command and the switch action relay stop drive command, and stop driving the switch protection relay and the switch action relay.

[0025] Optionally, the switch action control module is also used to start timing after the switch action relay is energized, and when the timing duration exceeds a second preset time, output a switch protection relay stop driving command.

[0026] Optionally, the switch position and switch protection relay acquisition interface is also used to collect the rear contact status information of the switch protection relay.

[0027] Optionally, the switch action control module is further used to output switch protection relay driving information after driving the switch protection relay.

[0028] Optionally, the device also includes: a switch protection relay fault alarm module, which is respectively connected to the switch action control module and the switch position and switch protection relay acquisition interface, and the switch protection relay fault alarm module is used to determine whether the switch protection relay is faulty based on the rear contact status information of the switch protection relay and the switch protection relay drive information, and issue a fault alarm message when it is determined that the switch protection relay is faulty.

[0029] Optionally, the switch protection relay fault alarm module is specifically used for:

[0030] Determine whether the switch protection relay is in a driving state according to the switch protection relay driving information, and when it is determined that the switch protection relay is in a driving state, determine whether the rear contact of the switch protection relay is always in a closed state according to the rear contact state information of the switch protection relay, and when it is determined that the rear contact is in a closed state, determine that the switch protection relay has a fault.

[0031] Optionally, the turnout action relay is a gravity-type safety relay, and the turnout protection relay is an AC contactor.

[0032] Optionally, the front contacts of the switch action relay and the switch protection relay are connected in series.

[0033] The present invention has at least the following technical effects:

[0034] (1) The switch operation relay uses a gravity safety relay. This type of relay has an inherent fault-safe feature. This feature prevents it from being erroneously sucked up, ensuring that the switch control circuit is not erroneously connected and the switch is not erroneously switched, thus avoiding the risk of train derailment or rollover in the switch area and personal injury at level crossings.

[0035] (2) The switch protection relay uses an AC contactor, and the front contacts of this type of relay can withstand the impact of large currents. When switching switches, the switch operation relay is energized before the switch protection relay. The large induced current at the moment the switch control circuit is connected is borne by the switch protection relay, avoiding the impact of the induced current on the switch operation relay, ensuring the service life of the switch operation relay, the normal switching of the switch, and the normal operation of the train;

[0036] (3) The switch protection relay uses an AC contactor, and the front contacts of this type of relay can withstand the impact of large currents. When the switch stops switching, the switch protection relay falls before the switch operation relay. The large induced current at the moment the switch control circuit is disconnected is borne by the switch protection relay, avoiding the impact of the induced current on the switch operation relay, ensuring the service life of the switch operation relay, the normal switching of the switch, and the normal operation of the train.

[0037] (4) After the switch protection relay is disconnected, the switch machine control circuit is disconnected, and the strong induction current generated by the switch machine coil is borne by the switch protection relay instead of the switch machine contact row, which increases the service life of the switch machine contact row and reduces the maintenance workload and maintenance cost of the switch machine.

[0038] (5) The switch control circuit proposed in this scheme uses fewer relays and a simple circuit, which is convenient for construction and subsequent maintenance.

[0039] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A tram switch control circuit diagram provided by an embodiment of the present invention;

[0041] Figure 2 A flow chart of a tramway switch control method provided by an embodiment of the present invention;

[0042] Figure 3 A flow chart of a tramway switch control method provided as a specific example of the present invention;

[0043] Figure 4 This is a structural block diagram of a tram switch control device provided by one embodiment of the present invention. DETAILED DESCRIPTION

[0044] The present embodiment is described in detail below, and examples of the embodiment are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0045] The tramway switch control method and device of this embodiment will be described below with reference to the accompanying drawings.

[0046] like Figure 1 As shown, the control circuit of the switch machine can be connected or disconnected by connecting the front contacts of the switch protection relay and the front contacts of the switch action relay in series. Among them, the switch protection relay QBJ can be an AC contactor, and its front contacts can withstand the induced current generated by the switch machine coil at the moment when the switch machine control circuit is connected or disconnected; the switch action relay DCJ / FCJ can be a gravity safety relay, and its front contacts control the direction of the switch machine switching, and at the same time can ensure that the switch machine control circuit will not be connected by mistake when the switch protection relay or the switch action relay fails. Specifically, when switching the switch, the switch action relay is driven to absorb first, and then the switch protection relay is driven to absorb after a period of time. The induced current at the moment when the switch machine control circuit is connected is borne by the front contacts of the switch protection relay; when stopping switching the switch, the switch protection relay is stopped first, and then the switch action relay is stopped after a period of time. The induced current at the moment when the switch machine control circuit is disconnected is borne by the front contacts of the switch protection relay.

[0047] Figure 2 Flow chart of a tramway switch control method provided by one embodiment of the present invention. Figure 2 As shown, the method includes:

[0048] Step S100: receiving a route handling or single turnout operation command, and determining whether the turnout operation conditions are met.

[0049] Among them, judging whether the switch action conditions are met includes: checking whether the switch section is in an idle state, and whether the switch section meets the conditions of not being locked by the route and not being locked individually.

[0050] Step S200: When the turnout action condition is met, the turnout action relay is driven to be attracted, and after a first preset time, the turnout protection relay is driven to be attracted.

[0051] Specifically, when the switch protection relay is driven to be attracted, the rear contact state of the switch protection relay can be collected, so as to judge whether the switch protection relay is faulty according to the rear contact state of the switch protection relay, and issue a fault alarm message when the switch protection relay fails.

[0052] Wherein, judging whether the switch protection relay is faulty according to the rear contact state of the switch protection relay includes: during the process of driving the switch protection relay, if the rear contact state of the switch protection relay is always in a closed state, then judging that the switch protection relay is faulty.

[0053] Step S300: collecting the switch position status, judging whether the switch has completed the position conversion according to the switch position status, and stopping driving the switch protection relay when the switch has completed the position conversion, and stopping driving the switch action relay after a first preset time.

[0054] Of course, the turnout protection relay can also be controlled to stop driving by whether it has timed out. For example, the timing starts after the turnout action relay is attracted, and when the timing time exceeds a second preset time, the turnout protection relay is stopped, wherein the second preset time is greater than the first preset time.

[0055] As a specific example, Figure 3 As shown, the method specifically comprises the following steps:

[0056] Step S1: After receiving the order from the duty officer to handle the route or single switch operation, check whether the section where the switch is located is idle, not locked by the route, and not locked individually. When all these conditions are met, it is determined that the switch operation conditions are met, otherwise the switch will not be operated.

[0057] Step S2: When the turnout action conditions are met, the turnout action relay is driven to be attracted. After the turnout action relay is attracted, its front contact is closed.

[0058] Step S3: start timing after the self-driving turnout action relay is energized, and when the timing reaches 1s, i.e. the first preset time, the driving turnout protection relay is energized. After the turnout protection relay is energized, its front contact is closed, and the control circuit of the switch machine is connected. The switch machine starts to move, and the turnout starts to switch. The induced current at the moment the switch machine control circuit is connected is borne by the turnout protection relay.

[0059] Step S4: The second preset time is started 30s after the self-driving turnout action relay is sucked up. During the timing, when the turnout is transferred to the specified position or the timing reaches 30s, the turnout protection relay is stopped. After the turnout protection relay falls, its front contact is disconnected, the switch machine control circuit is cut off, the turnout stops switching, and the instantaneous induction current generated by the switch machine coil is borne by the turnout protection relay.

[0060] Step S5: start timing after stopping driving the turnout protection relay, and after the timing reaches 1s, i.e. the first preset time, stop driving the turnout action relay. After the turnout action relay falls, its front contact is disconnected, and the entire control process of the turnout action is completed.

[0061] Step S6: Starting from the step S4 in which the switch protection relay is driven, the rear contact state of the switch protection relay is continuously collected.

[0062] Step S7: Determine whether the switch protection relay is faulty based on the information collected based on the status of the rear contact of the switch protection relay. If the rear contact of the switch protection relay is always closed during the process of driving the switch protection relay, it is determined that the switch protection relay is faulty and a fault alarm message is generated.

[0063] Figure 4 This is a structural block diagram of a tramway switch control device provided by an embodiment of the present invention. Figure 4 As shown, the tramway switch control device includes: a switch action control module a, a switch action relay and a switch protection relay drive interface b and a switch position and switch protection relay acquisition interface c. The device also includes a switch action relay d, a switch protection relay e, a switch machine control circuit f and a switch protection relay fault alarm module g.

[0064] Among them, the turnout action control module a, the turnout action relay and the turnout protection relay drive interface b, the turnout action relay d, and the switch machine control circuit f are connected in sequence; the turnout action control module a, the turnout action relay and the turnout protection relay drive interface b, the turnout protection relay e, and the switch machine control circuit f are connected in sequence; the turnout protection relay e, the turnout position and the turnout protection relay acquisition interface c, and the turnout protection relay fault alarm module g are connected in sequence; the turnout position and the turnout protection relay acquisition interface c, and the turnout action control module a are connected in sequence; the turnout action control module a and the turnout protection relay fault alarm module g are connected in sequence; the switch machine control circuit f is connected to the external switch machine; the turnout position and the turnout protection relay acquisition interface c is connected to the switch machine.

[0065] It should be noted that the switch action relay d can be a gravity-type safety relay, and the switch protection relay e can be an AC contactor, wherein the switch action relay d and the switch protection relay e are connected with their front contacts in series when connected.

[0066] In this embodiment, the functions of each module and device are as follows:

[0067] The turnout action control module a is specifically used to receive the command of handling the route or single-operation turnout, determine whether the turnout action conditions are met, and output the turnout action relay and the turnout protection relay drive command to the turnout action relay d and the turnout protection relay e when the turnout action conditions are met; receive the turnout position acquisition information, determine whether the turnout is in place, and output the turnout action relay and the turnout protection relay stop drive command to the turnout action relay d and the turnout protection relay e after the turnout is in place; time the turnout action relay d drive for 30 seconds, and after the time is over, output the turnout action relay and the turnout protection relay stop drive command to the turnout action relay d and the turnout protection relay e; control the action sequence of the turnout action relay d and the turnout protection relay e, specifically, when starting to move the turnout, first output the turnout action relay drive command, and then output the turnout protection relay drive command 1 second later, and when stopping the turnout, first output the turnout protection relay stop drive command, and then output the turnout action relay stop drive command 1 second later; and output the drive state of the turnout protection relay e to the turnout protection relay fault alarm module g.

[0068] The switch action relay and switch protection relay drive interface b is specifically used to receive the switch action relay drive command from the switch action control module a, and control the positive and negative drive power supplies of the switch action relay d to be turned on; receive the switch protection relay drive command from the switch action control module a, and control the positive and negative drive power supplies of the switch protection relay e to be turned on; receive the switch action relay stop drive command from the switch action control module a, and control the positive and negative drive power supplies of the switch action relay d to be turned off; receive the switch protection relay stop drive command from the switch action control module a, and control the positive and negative drive power supplies of the switch protection relay e to be turned off.

[0069] The switch position and switch protection relay acquisition interface c is specifically used to collect switch position information from the switch machine and transmit it to the switch action control module a; collect the switch protection relay rear contact status information and transmit it to the switch action control module a and the switch protection relay fault alarm module g respectively.

[0070] The switch action relay d is specifically used to be sucked up after the switch action relay and the switch protection relay drive interface b are connected to the positive and negative power supplies. When sucked up, its front contact is closed; and to fall down after the switch action relay and the switch protection relay drive interface b are disconnected from the positive or negative power supplies. When falling down, its front contact is disconnected; in addition, the closing or opening condition of the front contact is sent to the switch machine control circuit f.

[0071] The switch protection relay e is specifically used to be sucked up after the switch action relay and the switch protection relay drive interface b are connected to the positive and negative power supplies. When sucked up, its front contact is closed; it falls down after the switch action relay and the switch protection relay drive interface b are disconnected from the positive or negative power supplies. When falling down, its front contact is disconnected; in addition, the closing or opening condition of the front contact is sent to the switch machine control circuit f.

[0072] The switch machine control circuit f is specifically used to receive the closing and opening conditions of the front contacts of the switch operation relay d and the switch protection relay e, and to connect the power supply of the switch machine control circuit f when the front contacts of the switch operation relay d and the switch protection relay e are both closed, and to disconnect the power supply of the switch machine control circuit f when the front contacts of the switch operation relay d or the switch protection relay e are opened.

[0073] The switch protection relay fault alarm module g is specifically used to receive the driving information of the switch protection relay e from the switch action control module a; receive the switch protection relay rear contact collection information from the switch position and the switch protection relay collection interface c; judge whether the switch protection relay e is faulty according to the two information, and during the driving of the switch protection relay e, if it is determined that its rear contact is always in a closed state, it is judged that the switch protection relay e is faulty and a fault alarm information is issued.

[0074] As a specific example, the turnout action control module a receives a command for handling a route or single turnout operation, and when the turnout action condition is met, outputs a turnout action relay drive command, and after the turnout action relay is driven for a first preset time (such as 1s), outputs a turnout protection relay drive command. The turnout action relay and turnout protection relay drive interface b receives the turnout action relay drive command and the turnout protection relay drive command, and controls the turnout action relay to be attracted and the turnout protection relay to be attracted.

[0075] Further, the switch position and switch protection relay acquisition interface c acquires the switch position information and sends the switch position information to the switch action control module a, so that the switch action control module a outputs a switch protection relay stop drive command when determining that the switch has completed the position conversion according to the switch position information, and outputs a switch action relay stop drive command after a first preset time. The switch action relay and switch protection relay drive interface b receives the switch protection relay stop drive command and the switch action relay stop drive command, and stops driving the switch protection relay and the switch action relay.

[0076] Among them, the switch action control module a can also start timing after the switch action relay d is attracted, and when the timing time exceeds the second preset time (such as 30s), it outputs the switch protection relay stop driving command to stop driving control of the switch protection relay.

[0077] In this example, the switch position and switch protection relay acquisition interface c can also collect the rear contact status information of the switch protection relay e and send it to the switch protection relay fault alarm module g. The switch protection relay fault alarm module g can determine whether the switch protection relay e is faulty according to the rear contact status information of the switch protection relay e and the switch protection relay drive information, and issue a fault alarm message when it is determined that the switch protection relay e is faulty. For example, it is determined whether the switch protection relay e is in the driving state according to the switch protection relay drive information, and when it is determined that the switch protection relay e is in the driving state, it is determined whether the rear contact of the switch protection relay e is always in the closed state according to the rear contact status information of the switch protection relay e, and when it is determined that the rear contact is in the closed state, it is determined that the switch protection relay e is faulty.

[0078] In summary, the present invention adopts the method of connecting the front contact of the turnout protection relay and the front contact of the turnout action relay in series to connect or disconnect the control circuit of the switch machine. Among them, the turnout protection relay can be an AC contactor, and its front contact can withstand the induced current generated by the turnout machine coil when the turnout machine control circuit is connected or disconnected; the turnout action relay can be a gravity safety relay, and its front contact controls the direction of the turnout machine switching, and can ensure that the turnout machine control circuit will not be connected by mistake when the turnout protection relay or the turnout action relay fails. Specifically, when switching the turnout, the turnout action relay is driven to be sucked up first, and then the turnout protection relay is driven to be sucked up after a period of time, and the induced current at the moment of the turnout machine control circuit is connected is borne by the front contact of the turnout protection relay; when stopping switching the turnout, the turnout protection relay is stopped first, and then the turnout action relay is stopped after a period of time, and the induced current at the moment of the turnout machine control circuit is disconnected is borne by the front contact of the turnout protection relay. In this way, the safe switching of the turnout can be realized, the safe operation of the train can be guaranteed, and the service life of the relay can be extended, and the maintenance workload and maintenance cost of the turnout machine can be reduced.

[0079] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0080] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the present invention. After reading the above content, it will be apparent to those skilled in the art that various modifications and substitutions of the present invention will occur. Therefore, the protection scope of the present invention should be limited by the appended claims.

Claims

1. A tramway switch control method, characterized in that: include: Receive the command of route handling or single turnout operation, and judge whether the turnout action conditions are met; When the turnout action condition is met, the turnout action relay is driven to be attracted, and after the first preset time, the turnout protection relay is driven to be attracted; collecting the position status of the turnout, judging whether the turnout has completed the position conversion according to the position status of the turnout, and stopping driving the turnout protection relay when the turnout has completed the position conversion, and stopping driving the turnout action relay after the first preset time, The switch protection relay is an AC contactor, and the switch action relay is a gravity safety relay. The control circuit of the switch machine is connected or disconnected by connecting the front contacts of the switch protection relay and the front contacts of the switch operation relay in series, wherein the front contacts of the switch protection relay bear the induced current generated by the switch machine coil at the moment the switch machine control circuit is connected or disconnected; the front contacts of the switch operation relay control the switching direction of the switch machine to ensure that the switch machine control circuit will not be connected by mistake when the switch protection relay or the switch operation relay fails.

2. The tramway switch control method according to claim 1, characterized in that: Determining whether the turnout action conditions are met includes: checking whether the turnout section is in an idle state, and whether the turnout section meets the conditions of not being locked by the route and not being locked individually.

3. The tramway switch control method according to claim 2, characterized in that: The method further includes: starting timing after driving the switch action relay to be attracted, and stopping driving the switch protection relay when the timing duration exceeds a second preset time, wherein the second preset time is greater than the first preset time.

4. The tramway switch control method according to claim 3, characterized in that: The method also includes: when driving the switch protection relay to be attracted, collecting the rear contact state of the switch protection relay, so as to judge whether the switch protection relay is faulty according to the rear contact state of the switch protection relay, and issuing fault alarm information when the switch protection relay is faulty.

5. The tramway switch control method according to claim 4, characterized in that: Judging whether the switch protection relay is faulty according to the rear contact state of the switch protection relay includes: during the process of driving the switch protection relay, if the rear contact state of the switch protection relay is always in a closed state, then judging that the switch protection relay is faulty.

6. A tramway switch control device, characterized in that: include: A turnout action control module is used to receive a turnout handling or single turnout operation command, and output a turnout action relay drive command when the turnout action condition is met, and output a turnout protection relay drive command after the turnout action relay is driven for a first preset time; A turnout action relay and a turnout protection relay drive interface, connected to the turnout action control module, the turnout action relay and the turnout protection relay drive interface are used to receive the turnout action relay drive command and the turnout protection relay drive command, and control the turnout action relay to be attracted and the turnout protection relay to be attracted; A switch position and switch protection relay acquisition interface connected to the switch action control module, the switch position and switch protection relay acquisition interface is used to collect switch position information, so that the switch action control module outputs a switch protection relay stop driving command when determining that the switch has completed position conversion according to the switch position information, and outputs a switch action relay stop driving command after the first preset time; The switch action relay and switch protection relay drive interface is also used to receive the switch protection relay stop drive command and the switch action relay stop drive command, and stop driving the switch protection relay and the switch action relay. The switch action relay is a gravity type safety relay, and the switch protection relay is an AC contactor. The control circuit of the switch machine is connected or disconnected by connecting the front contacts of the switch protection relay and the front contacts of the switch operation relay in series, wherein the front contacts of the switch protection relay bear the induced current generated by the switch machine coil at the moment the switch machine control circuit is connected or disconnected; the front contacts of the switch operation relay control the switching direction of the switch machine to ensure that the switch machine control circuit will not be connected by mistake when the switch protection relay or the switch operation relay fails.

7. The tramway switch control device according to claim 6, characterized in that: The switch action control module is also used to start timing after the switch action relay is attracted, and output a switch protection relay stop driving command when the timing duration exceeds a second preset time.

8. The tramway switch control device according to claim 7, characterized in that: The switch position and switch protection relay acquisition interface is also used to collect the rear contact status information of the switch protection relay.

9. The tramway switch control device according to claim 8, characterized in that: The switch action control module is also used to output the switch protection relay driving information after driving the switch protection relay.

10. The tramway switch control device according to claim 9, characterized in that: Also includes: The switch protection relay fault alarm module is connected to the switch action control module and the switch position and switch protection relay acquisition interface respectively. The switch protection relay fault alarm module is used to determine whether the switch protection relay is faulty according to the rear contact status information of the switch protection relay and the switch protection relay drive information, and send out fault alarm information when it is determined that the switch protection relay is faulty.

11. The tramway switch control device according to claim 10, characterized in that: The switch protection relay fault alarm module is specifically used for: Determine whether the switch protection relay is in a driving state according to the switch protection relay driving information, and when it is determined that the switch protection relay is in a driving state, determine whether the rear contact of the switch protection relay is always in a closed state according to the rear contact state information of the switch protection relay, and when it is determined that the rear contact is in a closed state, determine that the switch protection relay has a fault.

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