Three-phase four-wire system switch machine control circuit and control method thereof

Abstract

According to the three-phase four-wire system switch machine control circuit and the control method thereof, one end is connected with a three-phase alternating-current power source and a direct-current power source, the other end is connected with a switch machine through four external wiring terminals W1, W2, W3 and W4, and the circuit comprises a power source switch unit and a control unit, the logic switch unit comprises a normally open contact LK-1NO, a normally open contact LK-2NO and a normally open contact LK-3NO; the logic auxiliary switch unit comprises three normally closed contacts (LKF-1NC, LKF-2NC and LKF-3NC); and a normally open contact LKF-4NO, and a normally open contact LKF-4NO, the forward switch unit comprises a normally open contact ZXJ-1NO, a normally open contact ZXJ-2NO, and a normally closed contact ZXJ-3NC; the reverse switch unit comprises two normally open contacts (FXJ-1NO and FXJ-2NO) and one normally closed contact (FXJ-3NC); and the position detection circuit is used for detecting the current forward position or reverse position of the switch machine.

Description

Technical Field

[0001] This article relates to the field of railway transportation, and in particular to a three-phase four-wire switch machine control circuit and a control method thereof. Background Art

[0002] The control of AC switch machine mainly adopts three-phase five-wire control method, and the implementation means mainly adopts the relay combination method inherited from 6502 electrical concentration and the control method of power electronic circuit.

[0003] The three-phase five-wire control method based on relay combination mainly uses gravity relay to achieve control, and the main problems are as follows:

[0004] 1. Large size: A single gravity relay is relatively large. To realize a turnout control circuit, at least 5 relays are required. The entire control circuit takes up a lot of space.

[0005] 2. Complex construction: relays, buttons, fuses, buttons and other devices used in the turnout control circuit need to be wired. The number of wires is large, the construction is difficult, and it is easy to make mistakes. Inspection and verification are also difficult.

[0006] 3. No monitoring: There is no monitoring circuit in the turnout control circuit, so it is impossible to detect the operating parameters during the turnout control process, and it is impossible to perform status analysis and fault prediction. If monitoring is required, a separate monitoring system needs to be added, which is complex and costly.

[0007] 4. Difficult maintenance: There are many components in the turnout control circuit and the wiring is complicated. Once a fault occurs, it is difficult to quickly locate the cause of the fault, which brings great pressure to system maintenance.

[0008] Based on the control method of power electronic circuit, the control principle of relay combination is realized by electronic devices, which overcomes the above-mentioned shortcomings of relay combination. However, the control method of power electronic circuit still has the following shortcomings:

[0009] 1. A large number of control lines: Five cables are required to connect the controller and the switch machine, and a large number of lead cables increase the connection cost and space cost;

[0010] 2. Complex peripherals: The external control of the switch machine requires additional configuration of position diodes and current-limiting resistors. When the diodes and current-limiting resistors fail, the control and position detection of the switch machine will also fail, increasing the number of fault points;

[0011] 3. Lack of cable integrity check: Controller operation requires three cables to achieve control, and position detection also requires three cables to achieve position detection. Since the cables required for operation and control are different, when executing control operations, it is impossible to detect whether the other two cables that do not participate in control are fully connected and whether the connection sequence is correct; similarly, when performing position detection, it is also impossible to detect whether the other two cables that do not participate in the detection are fully connected and whether the connection sequence is correct; since the above information cannot be obtained, it will seriously affect the integrity and availability of the circuit. Summary of the invention

[0012] The embodiment of the present application provides a three-phase four-wire switch machine control circuit and a control method thereof.

[0013] A three-phase four-wire switch machine control circuit, one end of which is connected to a three-phase AC power supply and a DC power supply respectively, and the other end is connected to the switch machine through four external connection terminals W1, W2, W3 and W4. The circuit comprises:

[0014] The power switch unit includes three switches SSR1, SSR2 and SSR3;

[0015] Logic switch unit, including 3 normally open contacts LK-1NO, LK-2NO and LK-3NO;

[0016] Logic auxiliary switch unit, including 3 normally closed contacts LKF-1NC, LKF-2NC and LKF-3NC; and 1 normally open contact LKF-4NO;

[0017] Positive switch unit, including 2 normally open contacts ZXJ-1NO and ZXJ-2NO and 1 normally closed contact ZXJ-3NC;

[0018] Reverse switch unit, including 2 normally open contacts FXJ-1NO and FXJ-2NO and 1 normally closed contact FXJ-3NC;

[0019] The position detection circuit is used to detect whether the switch machine is currently in the forward position or the reverse position; wherein:

[0020] One end of the normally open contact LK-1NO is connected to the A port of the three-phase AC power supply through the switch SSR1, and the other end is connected to one end of the normally open contact ZXJ-1NO and one end of the normally open contact FXJ-1NO respectively, wherein the other end of the normally open contact ZXJ-1NO is connected to the external wiring terminal W1, and the other end of the normally open contact FXJ-1NO is connected to the external wiring terminal W2;

[0021] One end of the normally open contact LK-2NO is connected to the B port of the three-phase AC power supply via the switch SSR2, and the other end is respectively connected to one end of the normally open contact ZXJ-2NO and one end of the normally open contact FXJ-2NO, wherein the other end of the normally open contact ZXJ-1NO is connected to the external wiring terminal W2 via FXJ-3CN, and the other end of the normally open contact FXJ-2NO is connected to the external wiring terminal W1 via the normally closed contact ZXJ-3NC;

[0022] One end of the normally open contact LK-3NO is connected to the C port of the three-phase AC power supply through the switch SSR2, and the other end is connected to the external wiring terminal W3;

[0023] One end of the normally closed contact LKF-1NC is connected to the negative pole of the DC power supply and is also connected to the external wiring terminal W4 through the normally open contact LKF-4NO, and the other end is connected between the normally open contact LK-1NO and the normally open contact ZXJ-1NO;

[0024] One end of the normally closed contact LKF-2NC is connected to the positive pole of the DC power supply, and the other end is connected between the normally open contact LK-3NO and the external wiring terminal W3;

[0025] One end of the normally closed contact LKF-3NC is connected between the normally open contact LK-2NO and the normally open contact ZXJ-2NO via the position detection circuit, and the other end is connected to the external connection terminal W4.

[0026] A control method for a three-phase four-wire switch control circuit is applied to the circuit described above, and the method comprises:

[0027] Receive control instructions;

[0028] According to the control instruction, the conduction state of the switch unit in the circuit is controlled; wherein:

[0029] When the control instruction is to control the switch machine to perform forward rotation, the power switch unit is turned on, the logic switch unit is powered on, the forward switch unit is powered on, the reverse switch unit is not powered on, and the logic auxiliary switch unit is powered on;

[0030] When the switch machine is controlled to perform reverse rotation, the power switch unit is turned on, the logic switch unit is powered on, the forward switch unit is not powered on, the reverse switch unit is powered on, and the logic auxiliary switch unit is powered on;

[0031] When the control instruction is to detect whether the switch machine is in the forward position, the power switch unit is disconnected, the logic switch unit is not powered on, the forward switch unit is powered on, the reverse switch unit is not powered on, and the logic auxiliary switch unit is not powered on;

[0032] When the control instruction is to detect whether the switch machine is in the reverse position, the power switch unit is disconnected, the logic switch unit is not powered on, the forward switch unit is not powered on, the reverse switch unit is powered on, and the logic auxiliary switch unit is not powered on;

[0033] When the control instruction is to detect whether the switch machine is in the four-open state, the power switch unit is disconnected, the logic switch unit is not powered on, the forward switch unit is not powered on, the reverse switch unit is powered on, and the logic auxiliary switch unit is not powered on.

[0034] The embodiment of the present application uses electronic components to construct the structure of the control function and the structure of the detection function in the three-phase four-wire switch machine, which has high integration, does not require redundant wiring, reduces on-site wiring, is simple to operate, and is easy to use.

[0035] Other features and advantages of the present application will be described in the following description, and partly become apparent from the description, or be understood by implementing the present application. Other advantages of the present application can be realized and obtained by the schemes described in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The accompanying drawings are used to provide an understanding of the technical solution of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present application and do not constitute a limitation on the technical solution of the present application.

[0037] Figure 1 A schematic diagram of the structure of a three-phase four-wire switch machine control circuit provided in an embodiment of the present application;

[0038] Figure 2 for Figure 1 Another schematic diagram of the circuit shown;

[0039] Figure 3 for Figure 2 Another schematic diagram of the circuit shown;

[0040] Figure 4 for Figure 3 The schematic diagram of the structure of the system consisting of the circuit and the switch machine shown;

[0041] Figure 5 A flow chart of a control method for a three-phase four-wire switch machine control circuit provided in an embodiment of the present application;

[0042] Figure 6 for Figure 4 The schematic diagram of the signal flow of the system shown in FIG. 1 under the condition of controlling the switch machine to perform forward rotation;

[0043] Figure 7 for Figure 4 The schematic diagram of the signal flow of the system shown in FIG. 1 under the condition of controlling the switch machine to perform forward rotation;

[0044] Figure 8 for Figure 4 The schematic diagram of the signal flow of the system shown in FIG. 1 under the condition of detecting whether the switch machine is in the forward position;

[0045] Fig. 9 for Figure 4 The schematic diagram of the signal flow of the system shown in the figure under the condition of detecting whether the switch machine is in the reverse position;

[0046] Fig.10 for Figure 4 The system shown is a schematic diagram of the signal flow when detecting whether the switch machine is in the four-open state. DETAILED DESCRIPTION

[0047] The present application describes multiple embodiments, but the description is exemplary rather than restrictive, and it is obvious to those skilled in the art that there may be more embodiments and implementations within the scope of the embodiments described in the present application. Although many possible feature combinations are shown in the drawings and discussed in the specific embodiments, many other combinations of the disclosed features are also possible. Unless specifically limited, any feature or element of any embodiment may be used in combination with any other feature or element in any other embodiment, or may replace any other feature or element in any other embodiment.

[0048] The present application includes and contemplates combinations of features and elements known to those of ordinary skill in the art. The embodiments, features and elements disclosed in the present application may also be combined with any conventional features or elements to form a unique invention scheme. Any features or elements of any embodiment may also be combined with features or elements from other invention schemes to form another unique invention scheme. Therefore, it should be understood that any feature shown and / or discussed in the present application may be implemented individually or in any appropriate combination. Therefore, except for the limitations made according to the attached claims and their equivalents, the embodiments are not subject to other restrictions. In addition, various modifications and changes may be made within the scope of protection of the attached claims.

[0049] In addition, when describing representative embodiments, the specification may have presented the method and / or process as a specific sequence of steps. However, to the extent that the method or process does not rely on the specific order of the steps described herein, the method or process should not be limited to the steps of the specific order described. As will be understood by those of ordinary skill in the art, other sequences of steps are also possible. Therefore, the specific sequence of the steps set forth in the specification should not be interpreted as a limitation to the claims. In addition, the claims for the method and / or process should not be limited to the steps of performing them in the order written, and those skilled in the art can easily understand that these sequences can be changed and still remain within the spirit and scope of the embodiments of the present application.

[0050] Figure 1 The schematic diagram of the structure of the three-phase four-wire switch machine control circuit provided in the embodiment of the present application. Figure 1 As shown, one end is connected to a three-phase AC power supply and a DC power supply respectively, and the other end is connected to the switch machine through four external connection terminals W1, W2, W3 and W4. The circuit includes a power switch unit, a logic switch unit, a logic auxiliary switch unit, a forward switch unit, a reverse switch unit and a position detection circuit; wherein:

[0051] The power switch unit includes three switches SSR1, SSR2 and SSR3;

[0052] Specifically, the power switch unit realizes the connection and disconnection of the AC 380VAC power supply. When the three-phase AC power supply is connected, it is the last to act; when the three-phase AC power supply is disconnected, it is the first to act.

[0053] The logic switch unit includes three normally open contacts LK-1NO, LK-2NO and LK-3NO; it realizes the logic control of the AC 380VAC power supply.

[0054] Among them, the normally open contact (Normally Open, NO) is a contact that is in an open state under normal conditions. When the coil is energized, the normally open contact will close. The function of the normally open contact is the normally closed contact (Normally Closed, NC), in which the normally closed contact is a contact that is in a closed state under normal conditions. When the coil is energized, the normally closed contact will open.

[0055] The logic auxiliary switch unit includes three normally closed contacts LKF-1NC, LKF-2NC and LKF-3NC; and one normally open contact LKF-4NO; wherein, the logic auxiliary switch unit serves as an auxiliary switch of the logic switch unit, and is mainly used to preferentially cut off the position detection circuit before the circuit is connected when the circuit performs the control function; and, after the circuit completes the control function and is ready to perform the detection function, immediately connect to the position detection circuit.

[0056] The forward switch unit includes two normally open contacts ZXJ-1NO and ZXJ-2NO and one normally closed contact ZXJ-3NC; it is used to control the switch machine to perform forward rotation; and to perform forward position detection operations.

[0057] The reverse switch unit includes two normally open contacts FXJ-1NO and FXJ-2NO and one normally closed contact FXJ-3NC; it is used to control the switch machine to perform reverse rotation; and to perform reverse position detection operations.

[0058] A position detection circuit is used to detect whether the switch machine is currently in a forward position or a reverse position;

[0059] Specifically, the position detection circuit is used to detect the current between the normally closed contact LKF-1NC and the negative pole of the DC power supply, and determine whether the switch machine is in the forward position or the reverse position based on a preset position detection threshold and the detected current.

[0060] The connection method of the above switch unit is described below:

[0061] One end of the normally open contact LK-1NO is connected to the A port of the three-phase AC power supply through the switch SSR1, and the other end is connected to one end of the normally open contact ZXJ-1NO and one end of the normally open contact FXJ-1NO respectively, wherein the other end of the normally open contact ZXJ-1NO is connected to the external wiring terminal W1, and the other end of the normally open contact FXJ-1NO is connected to the external wiring terminal W2;

[0062] One end of the normally open contact LK-2NO is connected to the B port of the three-phase AC power supply via the switch SSR2, and the other end is respectively connected to one end of the normally open contact ZXJ-2NO and one end of the normally open contact FXJ-2NO, wherein the other end of the normally open contact ZXJ-1NO is connected to the external wiring terminal W2 via FXJ-3CN, and the other end of the normally open contact FXJ-2NO is connected to the external wiring terminal W1 via the normally closed contact ZXJ-3NC;

[0063] One end of the normally open contact LK-3NO is connected to the C port of the three-phase AC power supply through the switch SSR2, and the other end is connected to the external wiring terminal W3;

[0064] One end of the normally closed contact LKF-1NC is connected to the negative pole of the DC power supply and is also connected to the external wiring terminal W4 through the normally open contact LKF-4NO, and the other end is connected between the normally open contact LK-1NO and the normally open contact ZXJ-1NO;

[0065] One end of the normally closed contact LKF-2NC is connected to the positive pole of the DC power supply, and the other end is connected between the normally open contact LK-3NO and the external wiring terminal W3;

[0066] One end of the normally closed contact LKF-3NC is connected between the normally open contact LK-2NO and the normally open contact ZXJ-2NO via the position detection circuit, and the other end is connected to the external connection terminal W4.

[0067] The circuit provided in the embodiment of the present application uses electronic components to construct the structure of the control function and the structure of the detection function in the three-phase four-wire switch machine. It is highly integrated, does not require redundant wiring, reduces on-site wiring, is simple to operate, and is easy to use.

[0068] Figure 2 for Figure 1 Another schematic diagram of the circuit shown. Figure 2 As shown, the circuit also includes:

[0069] The four-open detection circuit has one end connected to the positive pole of the DC current and the other end connected to one end of the normally closed contact LKF-2NC, which is used to detect whether the switch machine is currently rotating to the correct position.

[0070] Specifically, the four-open detection circuit is used to detect the current between the normally closed contact LKF-1NC and the negative pole of the DC power supply, and determine whether the switch machine has rotated to the correct position based on the preset four-open detection threshold and the detected current.

[0071] The circuit provided in the embodiment of the present application is additionally provided with a four-open detection circuit, which can more accurately identify the status of the external switch machine.

[0072] Continue to see Figure 2 , the circuit further comprises:

[0073] The current control unit has one end connected to the positive pole of the DC power supply and the other end connected to one end of the normally closed contact LKF-2NC, and is used to control the current passing through within a preset range.

[0074] Preferably, the current control unit may be implemented by a resistor device, wherein when the current control unit is implemented by a resistor, the current control unit may be referred to as a current limiting resistor.

[0075] The above-mentioned current control unit can provide protection and current diversion for the position detection circuit and the four-open detection circuit.

[0076] Figure 2 The external cables used by the structure corresponding to the control function and the structure corresponding to the detection function (i.e., the position detection circuit and the four-open detection circuit) in the circuit shown are the same, which can effectively reduce the connection of external cables, reduce cable costs, and simplify wiring; further, since the structure corresponding to the detection function in the circuit uses all the cables connected to the outside in the structure corresponding to the control function in the circuit, when any cable is not connected or has poor contact, safety risks can be discovered in time.

[0077] Figure 3 for Figure 2 Another schematic diagram of the circuit shown. Figure 3 As shown, the circuit also includes:

[0078] The three current sensors 1, 2 and 3 are used to detect the real-time current values ​​of the three input power supply lines; when the circuit is connected, the current sensor can collect the current signal, and when the circuit is disconnected, the current sensor cannot collect the current signal; wherein:

[0079] Current sensor 1, wherein one end of the current sensor 1 is connected to the A port of the three-phase AC current through the switch SSR1, and is also connected to the negative pole of the DC current; the other end is respectively connected to one end of the normally open contact LK-1NO and one end of the normally closed contact LKF-1NC.

[0080] One end of the current sensor 2 is connected to the B port of the three-phase AC current through the switch SSR2, and the other end is connected to one end of the normally open contact LK-2NO;

[0081] One end of the current sensor 3 is connected to the C port of the three-phase AC current through the switch SSR3, and the other end is connected to one end of the normally open contact LK-3NO;

[0082] Among them, when the three current sensors 1, 2 and 3 all detect current, it means that the switch machine performs forward rotation or reverse rotation; among the three current sensors 1, 2 and 3, only current sensor 1 detects current, which means that the switch machine performs forward position or reverse position or four-open state detection.

[0083] In the above circuit, at least one of the logic switch unit, the forward switch unit, the reverse switch unit and the power switch unit is a relay, a thyristor or a contactor; or, it is a circuit provided with at least one of a relay, a thyristor and a contactor; at least one of the four-open detection circuit and the position detection circuit is a circuit provided with a relay or an optical coupling unit. Since the device used in the circuit is small in size, it can realize PCB board layout, does not need to withstand high voltage, and has higher safety and reliability.

[0084] Figure 4 for Figure 3 The schematic diagram of the structure of the system consisting of the circuit and the switch machine is shown in FIG. Figure 4 As shown, the circuit is connected to the switch machine through four external connection terminals W1, W2, W3 and W4.

[0085] Among them, Figure 4 In the system shown, the current control unit is a current limiting resistor RL.

[0086] Wherein, the switch machine comprises:

[0087] The three coils L1, L2 and L3 can be the motor coils for controlling the rotation direction inside the switch machine;

[0088] 4 contacts ZC, FC, ZW and FW, where ZC corresponds to Figure 4 The switches marked with 1 and 1a in the figure represent positive control contacts; FC corresponds to Figure 4 The switches marked with 2 and 2a in the figure represent reverse control contacts; ZW corresponds to Figure 4 The switches marked with 3 and 3a in the figure represent the contacts for positive position detection; FW corresponds to Figure 4 The switches marked with 4 and 4a together in FIG. 1 represent contacts for detecting the reverse position.

[0089] The truth table of the four contacts in the switch machine and the switch machine status is shown in Table 1:

[0090] Location ZW FW ZC FC Positive position Conductivity disconnect disconnect Conductivity Reverse position disconnect Conductivity Conductivity disconnect Four open (not in place) disconnect disconnect Conductivity Conductivity

[0091] Table 1

[0092] Below Figure 4 The connection relationship of the switch machine in the system shown is explained as follows:

[0093] One end of the coil L1 is connected to the external connection terminal W1, and the other end is respectively connected to the side of the switch marked with 1 corresponding to the contact ZC and the side of the switch marked with 3 corresponding to the contact ZW, wherein the side of the switch marked with 3a corresponding to the contact ZW is connected to the external connection terminal W4;

[0094] One end of the coil L2 is connected to the external connection terminal W2, and the other end intersects with the side of the switch marked 1a corresponding to the contact ZC to form an intersection, the side of the switch marked 4 corresponding to the contact FW is connected to the intersection, and the side marked 4a is connected between the side of the switch marked 3a corresponding to the contact ZW and the external connection terminal W4;

[0095] One end of the coil L3 is connected to the external connection terminal W3, and the other end is connected to the above-mentioned intersection;

[0096] Among them, the side of the contact FC corresponding to the 2 mark in the switch is connected between the intersection and the side of the contact FW corresponding to the 4 mark in the switch, and the side marked 2a is connected between the other end of the coil L3 and the above-mentioned intersection.

[0097] by Figure 4 The control method is explained using the connection structure shown as an example:

[0098] Figure 5 The following is a flow chart of a control method for a three-phase four-wire switch control circuit provided in an embodiment of the present application. Figure 5As shown, the method is applied to the circuit described above, and the method includes:

[0099] Step 501: receiving a control instruction;

[0100] Step 502: Control the conduction state of the switch unit in the circuit according to the control instruction; wherein:

[0101] When the control instruction is to control the switch machine to perform forward rotation, the power switch unit is turned on, the logic switch unit is powered on, the forward switch unit is powered on, the reverse switch unit is not powered on, and the logic auxiliary switch unit is powered on;

[0102] When the control instruction is to control the switch machine to perform reverse rotation, the power switch unit is turned on, the logic switch unit is powered on, the forward switch unit is not powered on, the reverse switch unit is powered on, and the logic auxiliary switch unit is powered on;

[0103] When the control instruction is to detect whether the switch machine is in the forward position, the power switch unit is disconnected, the logic switch unit is not powered on, the forward switch unit is powered on, the reverse switch unit is not powered on, and the logic auxiliary switch unit is not powered on;

[0104] When the control instruction is to detect whether the switch machine is in the reverse position, the power switch unit is disconnected, the logic switch unit is not powered on, the forward switch unit is not powered on, the reverse switch unit is powered on, and the logic auxiliary switch unit is not powered on;

[0105] When the control instruction is to detect whether the switch machine is in the four-open state, the power switch unit is disconnected, the logic switch unit is not powered on, the forward switch unit is not powered on, the reverse switch unit is powered on, and the logic auxiliary switch unit is not powered on.

[0106] Preferably, when the control instruction is to control the switch machine to perform forward rotation or reverse rotation, the logic auxiliary switch unit is first controlled to be powered on, then the power-on status of the forward switch unit and the reverse open source unit is controlled, then the logic switch unit is controlled to be powered on, and finally the power switch unit is controlled to be turned on.

[0107] Specifically, when it is necessary to control the forward rotation of the switch machine, first cut off the power supply of the logic auxiliary switch, then turn on the power supply of the forward switch unit and switch the power supply of the reverse switch unit to support the forward rotation of the switch machine, then turn on the power supply of the logic switch, and finally turn on the power switch SSR to achieve normal control.

[0108] By the same token, when it is necessary to control the reverse rotation of the switch machine, first cut off the power supply of the logic auxiliary switch, then turn on the power supply of the reverse switch unit and cut off the power supply of the reverse switch unit to support the reverse rotation of the switch machine, then turn on the power supply of the logic switch, and finally turn on the power switch SSR to achieve normal control.

[0109] The method provided in the embodiment of the present application uses electronic components to construct the structure of the control function and the structure of the detection function in the three-phase four-wire switch machine. It has high integration, does not require redundant wiring, reduces on-site wiring, is simple to operate, and is easy to use.

[0110] The following are the different contents of the control instructions. Figure 4 The signal flow in the system shown is explained as follows:

[0111] 1. Control the switch machine to perform forward rotation

[0112] The status of the three-phase four-wire AC switch control circuit: the power switch unit is turned on, the logic switch unit is powered on, the forward switch unit is powered on, the reverse switch unit is not powered on, and the logic auxiliary switch unit is powered on; the status of the external switch is: the ZC contact is turned on, the FC contact is turned on, the ZW contact is disconnected, and the FW contact is disconnected.

[0113] Figure 6 for Figure 4 The schematic diagram of the signal flow of the system shown in Figure 1 is a schematic diagram of the signal flow of the system when the switch machine is controlled to perform forward rotation. Figure 6 As shown, Figure 4 There are three signal flows in the system shown, including:

[0114] Input three-phase power supply 380VAC_A to 380VAC_B port flow direction, 380VAC-A through switch SSR1 → current sensor 1 → normally open contact LK-1NO → normally open contact ZXJ-1NO → coil L1 of switch machine → contact ZC of switch machine → contact FC of switch machine → coil L2 of switch machine → normally closed contact FXJ-3NC → normally open contact ZXJ-2NO → normally open contact LK-2NO → current sensor 2 → switch SSR2 → 380VAC-B.

[0115] Input three-phase power 380VAC_A to 380VAC_C port flow direction, 380VAC-A through switch SSR1 → current sensor 1 → normally open contact LK-1NO → normally open contact ZXJ-1NO → coil L1 of switch machine → contact ZC of switch machine → coil L3 of switch machine → → normally open contact LK-3NO → current sensor 3 → switch SSR3 → 380VAC-C.

[0116] Input three-phase power supply 380VAC_B to 380VAC_C port flow direction, 380VAC-B through switch SSR2 → current sensor 2 → normally open contact LK-2NO → normally open contact ZXJ-2NO → normally closed contact FXJ-3NC → coil L2 of switch machine → contact FC of switch machine → coil L3 of switch machine → normally open contact LK-3NO → current sensor 3 → SSR3 → 380VAC-C.

[0117] It can be seen from the above content that the above circuit can normally control the switch machine to perform forward rotation.

[0118] 2. Control the switch machine to perform reverse rotation

[0119] The status of the three-phase four-wire AC switch control circuit: the power switch unit is turned on, the logic switch unit is powered on, the forward switch unit is not powered on, the reverse switch unit is powered on, and the logic auxiliary switch unit is powered on; the status of the external switch is: the ZC contact is turned on, the FC contact is turned on, the ZW contact is disconnected, and the FW contact is disconnected.

[0120] Figure 7 for Figure 4 The schematic diagram of the signal flow of the system shown in Figure 1 is a schematic diagram of the signal flow of the system when the switch machine is controlled to perform forward rotation. Figure 7 As shown, Figure 4 There are three signal flows in the system shown, including:

[0121] Input three-phase power supply 380VAC_A to 380VAC_B port flow direction, 380VAC-A through switch SSR1 → current sensor 1 → normally open contact LK-1NO → normally open contact FXJ-1NO → coil L2 of switch machine → contact FC of switch machine → contact ZC of switch machine → coil L1 of switch machine → normally closed contact ZXJ-3NC → normally open contact FXJ-2NO → normally open contact LK-2NO → current sensor 2 → switch SSR2 → 380VAC-B.

[0122] Input three-phase power 380VAC_A to 380VAC_C port flow direction, 380VAC-A through switch SSR1 → current sensor 1 → normally open contact LK-1NO → normally open contact FXJ-1NO → coil L2 of switch machine → contact FC of switch machine → coil L3 of switch machine → → normally open contact LK-3NO → current sensor 3 → switch SSR3 → 380VAC-C.

[0123] Input three-phase power supply 380VAC_B to 380VAC_C port flow direction, 380VAC-B through switch SSR2 → current sensor 2 → normally open contact LK-2NO → normally open contact FXJ-2NO → normally closed contact ZXJ-3NC → coil L1 of switch machine → contact ZC of switch machine → coil L3 of switch machine → normally open contact LK-3NO → current sensor 3 → switch SSR3 → 380VAC-C.

[0124] It can be seen from the above content that the above circuit can normally control the switch machine to perform reverse rotation.

[0125] 3. Check whether the switch machine is in the forward position

[0126] The status of the three-phase four-wire AC switch control circuit: the power switch unit is disconnected, the logic switch unit is not powered, the forward switch unit is powered, the reverse switch unit is not powered, and the logic auxiliary switch unit is not powered; the status of the external switch is: the ZC contact is disconnected, the FC contact is turned on, the ZW contact is turned on, and the FW contact is disconnected.

[0127] Figure 8 for Figure 4 The schematic diagram of the signal flow of the system shown in the figure is when detecting whether the switch machine is in the forward position. Figure 8 As shown, Figure 4 There is one signal flow in the system shown, where:

[0128] Positive pole of DC power supply 60V+→current limiting resistor RL→four-open detection circuit→normally closed contact LKF-2NC→external connection terminal W3→coil L3 of switch machine→contact FC of switch machine→coil L2 of switch machine→external connection terminal W2→normally closed contact FXJ-3NC→normally open contact ZXJ-2NO→position detection circuit→normally closed contact LKF-3NC→external connection terminal W4→contact ZW of switch machine→coil L1 of switch machine→external connection terminal W1→normally open contact ZXJ-1NO→normally closed contact LKF-1NC→current sensor 1→negative pole of DC power supply 60V-.

[0129] It can be seen from the above content that the above circuit can detect whether the switch machine is in the forward position.

[0130] 4. Check whether the switch machine is in the forward position

[0131] The status of the three-phase four-wire AC switch control circuit: the power switch unit is disconnected, the logic switch unit is not powered on, the forward switch unit is not powered on, the reverse switch unit is powered on, and the logic auxiliary switch unit is not powered on; the status of the external switch is: the ZC contact is turned on, the FC contact is disconnected, the ZW contact is disconnected, and the FW contact is turned on.

[0132] Fig. 9 for Figure 4 The schematic diagram of the signal flow of the system shown in Figure 1 is when the system detects whether the switch is in the reverse position. Fig. 9 As shown, Figure 4 There is one signal flow in the system shown, where:

[0133] Positive pole of DC power supply 60V+→current limiting resistor RL→four-open detection circuit→normally closed contact LKF-2NC→external connection terminal W3→coil L3 of switch machine→contact ZC of switch machine→coil L1 of switch machine→external connection terminal W1→normally closed contact ZXJ-3NC→normally open contact FXJ-2NO→position detection circuit→normally closed contact LKF-3NC→external connection terminal W4→contact FW of switch machine→coil L2 of switch machine→external connection terminal W2→normally open contact FXJ-1NO→normally closed contact LKF-1NC→current sensor 1→negative pole of DC power supply 60V-.

[0134] It can be seen from the above content that the above circuit can detect whether the switch machine is in the reverse position.

[0135] 5. Check whether the switch machine is in the four-open state

[0136] The status of the three-phase four-wire AC switch control circuit: the power switch unit is disconnected, the logic switch unit is not powered on, the forward switch unit is not powered on, the reverse switch unit is powered on, and the logic auxiliary switch unit is not powered on; the status of the external switch is: the ZC contact is turned on, the FC contact is turned on, the ZW contact is disconnected, and the FW contact is disconnected.

[0137] Fig.10 for Figure 4 The schematic diagram of the signal flow of the system when detecting whether the switch machine is in the four-open state is shown. Fig.10 As shown, Figure 4 There is one signal flow in the system shown, where:

[0138] Positive pole of DC power supply 60V+→current limiting resistor RL→four-open detection circuit→normally closed contact LKF-2NC→external connection terminal W3→coil L3 of switch machine→contact FC of switch machine→coil L2 of switch machine→external connection terminal W2→normally open contact FXJ-1NO→normally closed contact LKF-1NC→current sensor 1→negative pole of DC power supply 60V-.

[0139] From the above content, it can be seen that the above circuit can detect whether the switch machine is in the four-open state.

[0140] exist Figures 8 to 10The signal flow shown is the signal flow under the condition that the circuit performs the detection function. From the signal flow, it can be seen that the external cables used to realize the switch control function and the detection function (that is, the four-open detection circuit and the position detection circuit) are the same, that is, they are all realized through 4 external wiring terminals, which can effectively reduce the connection of external cables, reduce cable costs, and simplify wiring. Furthermore, since the structure corresponding to the detection function in the circuit uses all the cables connected to the outside in the structure corresponding to the control function in the circuit, when any cable is not connected or has poor contact, safety risks can be discovered in time.

[0141] In summary, the solution provided in the embodiment of the present application has the following advantages, including:

[0142] 1) The control function structure and detection function structure of the three-phase four-wire switch machine are constructed using electronic components, which is highly integrated and does not require redundant wiring, reduces on-site wiring, is simple to operate, and is easy to use;

[0143] 2) The devices used in the circuit are small in size, can realize PCB board layout, do not need to withstand high voltage, and have higher safety and reliability;

[0144] 3) A four-open detection circuit is added to more accurately identify the status of the external switch machine.

[0145] 4) The external cables used by the structures corresponding to the control function and the detection function in the circuit are the same, which can effectively reduce the connection of external cables, reduce cable costs, and simplify wiring;

[0146] 5) Since the structure corresponding to the detection function in the circuit uses all cables connected to the outside in the structure corresponding to the control function in the circuit, when any cable is not connected or has poor contact, safety risks can be discovered in time.

[0147] It will be appreciated by those skilled in the art that all or some of the steps, systems, and functional modules / units in the methods disclosed above may be implemented as software, firmware, hardware, and appropriate combinations thereof. In hardware implementations, the division between the functional modules / units mentioned in the above description does not necessarily correspond to the division of physical components; for example, a physical component may have multiple functions, or a function or step may be performed by several physical components in cooperation. Some or all components may be implemented as software executed by a processor, such as a digital signal processor or a microprocessor, or implemented as hardware, or implemented as an integrated circuit, such as an application-specific integrated circuit. Such software may be distributed on a computer-readable medium, which may include a computer storage medium (or non-transitory medium) and a communication medium (or temporary medium). As known to those skilled in the art, the term "computer storage medium" includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tapes, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired information and can be accessed by a computer. In addition, it is well known to those skilled in the art that communication media generally contain computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and Figure 4 Any information delivery medium is present in the system shown.

Claims

1. A three-phase four-wire switch machine control circuit, one end of which is connected to a three-phase AC power supply and a DC power supply respectively, and the other end is connected to the switch machine through four external connection terminals W1, W2, W3 and W4, the circuit comprising: The power switch unit includes three switches SSR1, SSR2 and SSR3; Logic switch unit, including 3 normally open contacts LK-1NO, LK-2NO and LK-3NO; Logic auxiliary switch unit, including 3 normally closed contacts LKF-1NC, LKF-2NC and LKF-3NC; and 1 normally open contact LKF-4NO; Positive switch unit, including 2 normally open contacts ZXJ-1NO and ZXJ-2NO and 1 normally closed contact ZXJ-3NC; Reversing switch unit, including 2 normally open contacts FXJ-1NO and FXJ-2NO and 1 normally closed contact FXJ-3NC; The position detection circuit is used to detect whether the switch machine is currently in the forward position or the reverse position; wherein: One end of the normally open contact LK-1NO is connected to the A port of the three-phase AC power supply through the switch SSR1, and the other end is connected to one end of the normally open contact ZXJ-1NO and one end of the normally open contact FXJ-1NO respectively, wherein the other end of the normally open contact ZXJ-1NO is connected to the external wiring terminal W1, and the other end of the normally open contact FXJ-1NO is connected to the external wiring terminal W2; One end of the normally open contact LK-2NO is connected to the B port of the three-phase AC power supply via the switch SSR2, and the other end is respectively connected to one end of the normally open contact ZXJ-2NO and one end of the normally open contact FXJ-2NO, wherein the other end of the normally open contact ZXJ-1NO is connected to the external wiring terminal W2 via FXJ-3CN, and the other end of the normally open contact FXJ-2NO is connected to the external wiring terminal W1 via the normally closed contact ZXJ-3NC; One end of the normally open contact LK-3NO is connected to the C port of the three-phase AC power supply through the switch SSR2, and the other end is connected to the external wiring terminal W3; One end of the normally closed contact LKF-1NC is connected to the negative pole of the DC power supply and is also connected to the external wiring terminal W4 through the normally open contact LKF-4NO, and the other end is connected between the normally open contact LK-1NO and the normally open contact ZXJ-1NO; One end of the normally closed contact LKF-2NC is connected to the positive pole of the DC power supply, and the other end is connected between the normally open contact LK-3NO and the external wiring terminal W3; One end of the normally closed contact LKF-3NC is connected between the normally open contact LK-2NO and the normally open contact ZXJ-2NO via the position detection circuit, and the other end is connected to the external connection terminal W4.

2. The circuit according to claim 1, characterized in that: The position detection circuit is used to detect the current between the normally closed contact LKF-1NC and the negative pole of the DC power supply, and determine whether the switch machine is in the forward position or the reverse position based on a preset position detection threshold and the detected current.

3. The circuit according to claim 1, characterized in that The circuit also includes The four-open detection circuit has one end connected to the positive pole of the DC current and the other end connected to one end of the normally closed contact LKF-2NC, which is used to detect whether the switch machine is currently rotating to the correct position.

4. The circuit according to claim 3, characterized in that: The four-open detection circuit is used to detect the current between the normally closed contact LKF-1NC and the negative pole of the DC power supply, and determine whether the switch machine has rotated to the correct position based on the preset four-open detection threshold and the detected current.

5. The circuit according to claim 2 or 4, characterized in that: The circuit further comprises: One end of the current sensor 1 is connected to the A port of the three-phase AC current through the switch SSR1, and is also connected to the negative pole of the DC current; the other end is respectively connected to one end of the normally open contact LK-1NO and one end of the normally closed contact LKF-1NC.

6. The circuit according to claim 5, characterized in that The circuit further comprises: 2 current sensors 2 and 3; One end of the current sensor 2 is connected to the B port of the three-phase AC current through the switch SSR2, and the other end is connected to one end of the normally open contact LK-2NO; One end of the current sensor 3 is connected to the C port of the three-phase AC current through the switch SSR3, and the other end is connected to one end of the normally open contact LK-3NO; Among them, when the three current sensors 1, 2 and 3 all detect current, it means that the switch machine performs forward rotation or reverse rotation; among the three current sensors 1, 2 and 3, only current sensor 1 detects current, which means that the switch machine performs forward position or reverse position or four-open state detection.

7. The circuit according to claim 1, characterized in that The circuit further comprises: The current control unit has one end connected to the positive pole of the DC power supply and the other end connected to one end of the normally closed contact LKF-2NC, and is used to control the current passing through within a preset range.

8. The circuit according to claim 3, characterized in that: At least one of the logic switch unit, the forward switch unit, the reverse switch unit and the power switch unit is a relay, a thyristor or a contactor; or a circuit provided with at least one of a relay, a thyristor and a contactor; At least one of the four-open detection circuit and the position detection circuit is a circuit provided with a relay or an optical coupling unit.

9. A control method for a three-phase four-wire switch control circuit, applied to the circuit according to any one of claims 1 to 8, the method comprising: Receive control instructions; According to the control instruction, the conduction state of the switch unit in the circuit is controlled; wherein: When the control instruction is to control the switch machine to perform forward rotation, the power switch unit is turned on, the logic switch unit is powered on, the forward switch unit is powered on, the reverse switch unit is not powered on, and the logic auxiliary switch unit is powered on; When the control instruction is to control the switch machine to perform reverse rotation, the power switch unit is turned on, the logic switch unit is powered on, the forward switch unit is not powered on, the reverse switch unit is powered on, and the logic auxiliary switch unit is powered on; When the control instruction is to detect whether the switch machine is in the forward position, the power switch unit is disconnected, the logic switch unit is not powered on, the forward switch unit is powered on, the reverse switch unit is not powered on, and the logic auxiliary switch unit is not powered on; When the control instruction is to detect whether the switch machine is in the reverse position, the power switch unit is disconnected, the logic switch unit is not powered on, the forward switch unit is not powered on, the reverse switch unit is powered on, and the logic auxiliary switch unit is not powered on; When the control instruction is to detect whether the switch machine is in the four-open state, the power switch unit is disconnected, the logic switch unit is not powered on, the forward switch unit is not powered on, the reverse switch unit is powered on, and the logic auxiliary switch unit is not powered on.

10. The method according to claim 9, characterized in that: When the control instruction is to control the switch machine to perform forward rotation or reverse rotation, the logic auxiliary switch unit is first controlled to be powered on, then the power-on status of the forward switch unit and the reverse open unit is controlled, then the logic switch unit is controlled to be powered on, and finally the power switch unit is controlled to be turned on.

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