Control brake circuit of three-station mechanism and detection method of control brake circuit

Abstract

The invention belongs to the technical field of circuit detection, and discloses a control brake circuit of a three-station mechanism and a detection method thereof, and the control brake circuit comprises an isolation switch motor loop and brake loop, an isolation switch control loop, a grounding switch motor loop and brake loop, and a grounding switch control loop. The invention provides a control brake circuit of a three-station mechanism and a detection method thereof, and the control brake circuit comprises an isolation switch motor loop and a brake loop, an isolation switch control loop, a grounding switch motor loop and a brake loop, and a grounding switch control loop, and can achieve the positive and negative rotation of an isolation motor and a grounding motor. And the three-station mechanism is driven to realize three working states of isolation switching-on, switching-off and grounding switching-on. The brake loop of the isolating switch and the grounding switch can realize quick braking of the motor after the mechanism is switched on and switched off in place, and solves the problem of overshoot movement of the mechanism. The invention also provides a detection method for detecting whether the brake circuit is normal or not by measuring the resistance value of the circuit.

Description

Technical Field

[0001] The present invention belongs to, but is not limited to, the field of circuit detection technology, and particularly relates to a control and braking circuit for a three-position mechanism and a detection method thereof. Background Art

[0002] The three-position isolating earthing switch is widely used in GIS metal-enclosed switchgear. The three-position mechanism can drive the three-position isolating earthing switch to achieve three working states: isolating closing, opening, and earthing closing. When the three-position mechanism reaches the in-place position during opening and closing, mechanical overshoot will occur due to the movement inertia. When the movement resistance of the main body is small or the motor voltage is high, the mechanical overshoot may be relatively large, which may cause mechanical jamming, resulting in a large resistance during the next start. Therefore, the motor of the three-position mechanism often has the defect of being burned out, affecting the safe operation of the switchgear. Summary of the Invention

[0003] Aiming at the problems existing in the prior art, the present invention provides a control and braking circuit for a three-position mechanism and a detection method thereof.

[0004] The core innovation point of the present invention is to provide a control and braking circuit for a three-position mechanism. By designing the opening and closing control and braking circuits for the isolating switch and the earthing switch, the forward and reverse control and rapid braking of the motor are realized. At the same time, the energy is consumed by connecting a series resistor to limit the current and ensure the safety of the circuit. The system adopts precise interlocking control among the contactor, auxiliary switch, travel switch and motor, and innovatively realizes the electrical interlocking function between isolation and earthing, ensuring that the earthing switch cannot operate when the isolating switch is closed, and the isolating switch cannot operate when the earthing switch is closed, avoiding short-circuit problems caused by misoperation or parasitic circuits. At the same time, through the design of the self-holding circuit, the signal transmission and circuit efficiency are optimized, making the whole system have high reliability and precise operation performance, effectively improving the control accuracy and safety of the three-position mechanism in industrial automation.

[0005] The present invention is realized as follows. A control and braking circuit for a three-position mechanism, the control and braking circuit includes: an isolating switch motor circuit and a braking circuit, an isolating switch control circuit, an earthing switch motor circuit and a braking circuit, and an earthing switch control circuit.

[0006] Further, the isolating switch motor circuit and the braking circuit can be divided into an isolating switch opening motor circuit, an isolating switch closing motor circuit, an isolating switch opening braking circuit, and an isolating switch closing braking circuit;

[0007] The disconnector opening motor circuit includes a contactor KM1 and a motor M1. The first input power supply L is connected to the first end 23 of the first normally open contact of the contactor KM1. The second end 24 of the first normally open contact of the contactor KM1 is connected to the second end ZH2 of the armature winding of the motor M1. The first end ZH1 of the armature winding of the motor M1 is connected to the first end 13 of the second normally open contact of the contactor KM1. The second end 14 of the second normally open contact of the contactor KM1 is connected to the first end D3 of the field winding of the motor M1. The second end D4 of the field winding of the motor M1 is connected to the first end 44 of the third normally open contact of the contactor KM1. The second end 43 of the third normally open contact of the contactor KM1 is connected to the second input power supply N.

[0008] The disconnector closing motor circuit includes a contactor KM2 and a motor M1. The first input power supply L is connected to the first end 23 of the first normally open contact of the contactor KM2. The second end 24 of the first normally open contact of the contactor KM2 is connected to the first end ZH1 of the armature winding of the motor M1. The second end ZH2 of the armature winding of the motor M1 is connected to the first end 13 of the second normally open contact of the contactor KM2. The second end 14 of the second normally open contact of the contactor KM2 is connected to the first end D3 of the field winding of the motor M1. The second end D4 of the field winding of the motor M1 is connected to the first end 44 of the third normally open contact of the contactor KM2. The second end 43 of the third normally open contact of the contactor KM2 is connected to the second input power supply N.

[0009] The disconnector opening braking circuit includes a contactor KM1, a contactor KM2, a motor M1, a resistor R1, and an auxiliary switch DL1. The first end 1 of the resistor R1 is connected to the first end 82 of the first normally closed contact of the contactor KM2. The second end 81 of the first normally closed contact of the contactor KM2 is connected to the first end 82 of the first normally closed contact of the contactor KM1. The second end 81 of the first normally closed contact of the contactor KM1 is connected to the first end ZH1 of the armature winding of the motor M1. The second end ZH2 of the armature winding of the motor M1 is connected to the first end 71 of the second normally closed contact of the contactor KM1. The second end 72 of the second normally closed contact of the contactor KM1 is connected to the first end 71 of the second normally closed contact of the contactor KM2. The second end 72 of the second normally closed contact of the contactor KM2 is connected to the first end 9 of the first normally closed contact of the auxiliary switch DL1. The second end 11 of the first normally closed contact of the auxiliary switch DL1 is connected to the first end D3 of the field winding of the motor M1. The second end D4 of the field winding of the motor M1 is connected to the first end 5 of the second normally closed contact of the auxiliary switch DL1. The second end 7 of the second normally closed contact of the auxiliary switch DL1 is connected to the second section 2 of the resistor R1.

[0010] The closing braking circuit of the disconnector includes contactor KM1, contactor KM2, motor M1, resistor R1, and auxiliary switch DL1. The first end 1 of resistor R1 is connected to the first end 82 of the first normally closed contact of contactor KM2. The second end 81 of the first normally closed contact of contactor KM2 is connected to the first end 82 of the first normally closed contact of contactor KM1. The second end 81 of the first normally closed contact of contactor KM1 is connected to the first end ZH1 of the armature winding of motor M1. The second end ZH2 of the armature winding of motor M1 is connected to the first end 71 of the second normally closed contact of contactor KM1. The second end 72 of the second normally closed contact of contactor KM1 is connected to the first end 71 of the second normally closed contact of contactor KM2. The second end 72 of the second normally closed contact of contactor KM2 is connected to the first end 2 of the first normally open contact of auxiliary switch DL1. The second end 4 of the first normally open contact of auxiliary switch DL1 is connected to the second end D4 of the excitation winding of motor M1. The first end D3 of the excitation winding of motor M1 is connected to the first end 6 of the second normally open contact of auxiliary switch DL1. The second end 8 of the second normally open contact of auxiliary switch DL1 is connected to the second section 2 of resistor R1.

[0011] Furthermore, the motor circuit and braking circuit of the disconnector control the forward and reverse rotation of an AC / DC dual-purpose motor through two contactors to achieve the opening and closing actions of the disconnector; control the motor to brake through two contactors and an auxiliary switch, and connect a resistor in series to consume energy and limit the current.

[0012] Furthermore, the control circuit of the disconnector can be divided into a disconnector opening control circuit and a disconnector closing control circuit;

[0013] The disconnector opening control circuit includes contactor KM1, contactor KM2, contactor KM3, contactor KM4, isolating opening-in-place travel switch CK1, isolating manual locking travel switch CK5, and auxiliary switch DL2. The first input power supply L is connected to the first end 33 of the fourth normally open contact of contactor KM1. The second end 34 of the fourth normally open contact of contactor KM1 is connected to the first end 51 of the third normally closed contact of contactor KM2. The first end 51 of the third normally closed contact of contactor KM2 is simultaneously connected to the isolating opening signal power supply. The second end 52 of the third normally closed contact of contactor KM2 is connected to the first end A1 of the coil of contactor KM1. The second end A2 of the coil of contactor KM1 is connected to the first end 1 of the first normally open contact of isolating opening-in-place travel switch CK1. The second end 2 of the first normally open contact of isolating opening-in-place travel switch CK1 is connected to the first end 1 of the first normally closed contact of isolating manual locking travel switch CK5. The second end 2 of the first normally closed contact of isolating manual locking travel switch CK5 is connected to the first end 1 of the third normally closed contact of auxiliary switch DL2, and the second end 3 of the third normally closed contact of auxiliary switch DL2 is connected to the first end 61 of the third normally closed contact of contactor KM3. The second end 62 of the third normally closed contact of contactor KM3 is connected to the first end 62 of the third normally closed contact of contactor KM4. The second end 61 of the third normally closed contact of contactor KM4 is connected to the second input power supply N through the interlock condition;

[0014] The disconnector closing control loop includes contactor KM1, contactor KM2, contactor KM3, contactor KM4, isolating closing in-place travel switch CK2, earthing opening in-place travel switch CK3, isolating manual locking travel switch CK5, and auxiliary switch DL2. The first input power supply L is connected to the first end 33 of the fourth normally open contact of contactor KM2. The second end 34 of the fourth normally open contact of contactor KM2 is connected to the first end 51 of the third normally closed contact of contactor KM1. The first end 51 of the third normally closed contact of contactor KM1 is simultaneously connected to the isolating closing signal power supply. The second end 52 of the third normally closed contact of contactor KM1 is connected to the first end A1 of the coil of contactor KM2. The second end A2 of the coil of contactor KM1 is connected to the first end 1 of the first normally closed contact of isolating closing in-place travel switch CK2. The second end 2 of the first normally closed contact of isolating closing in-place travel switch CK2 is connected to the first end 3 of the first normally closed contact of earthing opening in-place travel switch CK3. The second end 4 of the first normally closed contact of earthing opening in-place travel switch CK3 is connected to the first end 1 of the first normally closed contact of isolating manual locking travel switch CK5. The second end 2 of the first normally closed contact of isolating manual locking travel switch CK5 is connected to the first end 1 of the third normally closed contact of auxiliary switch DL2. The second end 3 of the third normally closed contact of auxiliary switch DL2 is connected to the first end 61 of the third normally closed contact of contactor KM3. The second end 62 of the third normally closed contact of contactor KM3 is connected to the first end 62 of the third normally closed contact of contactor KM4. The second end 61 of the third normally closed contact of contactor KM4 is connected to the second input power supply N through an interlocking condition.

[0015] Further, the earthing switch motor loop and the braking loop can be divided into an earthing switch opening motor loop, an earthing switch closing motor loop, an earthing switch opening braking loop, and an earthing switch closing braking loop;

[0016] The earthing switch motor loop and the braking loop control the forward and reverse rotation of an AC / DC dual-purpose motor through two contactors to achieve the opening and closing actions of the earthing switch; control the motor to brake through two contactors and an auxiliary switch, and connect a resistor in series to consume energy and limit the current;

[0017] The opening motor circuit of the earthing switch includes contactor KM3 and motor M2. The first input power supply L is connected to the first end 23 of the first normally open contact of contactor KM3. The second end 24 of the first normally open contact of contactor KM3 is connected to the second end ZH2 of the armature winding of motor M2. The first end ZH1 of the armature winding of motor M2 is connected to the first end 13 of the second normally open contact of contactor KM3. The second end 14 of the second normally open contact of contactor KM3 is connected to the first end D3 of the excitation winding of motor M2. The second end D4 of the excitation winding of motor M2 is connected to the first end 44 of the third normally open contact of contactor KM3. The second end 43 of the third normally open contact of contactor KM3 is connected to the second input power supply N.

[0018] The closing motor circuit of the earthing switch includes contactor KM4 and motor M2. The first input power supply L is connected to the first end 23 of the first normally open contact of contactor KM4. The second end 24 of the first normally open contact of contactor KM4 is connected to the first end ZH1 of the armature winding of motor M2. The second end ZH2 of the armature winding of motor M2 is connected to the first end 13 of the second normally open contact of contactor KM4. The second end 14 of the second normally open contact of contactor KM4 is connected to the first end D3 of the excitation winding of motor M2. The second end D4 of the excitation winding of motor M2 is connected to the first end 44 of the third normally open contact of contactor KM4. The second end 43 of the third normally open contact of contactor KM4 is connected to the second input power supply N.

[0019] The opening braking circuit of the earthing switch includes contactor KM3, contactor KM4, motor M2, resistor R1, and auxiliary switch DL2. The first end 1 of resistor R1 is connected to the first end 82 of the first normally closed contact of contactor KM4. The second end 81 of the first normally closed contact of contactor KM4 is connected to the first end 82 of the first normally closed contact of contactor KM3. The second end 81 of the first normally closed contact of contactor KM3 is connected to the first end ZH1 of the armature winding of motor M2. The second end ZH2 of the armature winding of motor M2 is connected to the first end 71 of the second normally closed contact of contactor KM3. The second end 72 of the second normally closed contact of contactor KM3 is connected to the first end 71 of the second normally closed contact of contactor KM4. The second end 72 of the second normally closed contact of contactor KM4 is connected to the first end 9 of the first normally closed contact of auxiliary switch DL2. The second end 11 of the first normally closed contact of auxiliary switch DL2 is connected to the first end D3 of the excitation winding of motor M2. The second end D4 of the excitation winding of motor M2 is connected to the first end 5 of the second normally closed contact of auxiliary switch DL2. The second end 7 of the second normally closed contact of auxiliary switch DL2 is connected to the second section 2 of resistor R1.

[0020] The closing braking circuit of the earthing switch includes contactor KM3, contactor KM4, motor M2, resistor R1, and auxiliary switch DL2. The first end 1 of resistor R1 is connected to the first end 82 of the first normally closed contact of contactor KM4. The second end 81 of the first normally closed contact of contactor KM4 is connected to the first end 82 of the first normally closed contact of contactor KM3. The second end 81 of the first normally closed contact of contactor KM3 is connected to the first end ZH1 of the armature winding of motor M2. The second end ZH2 of the armature winding of motor M2 is connected to the first end 71 of the second normally closed contact of contactor KM3. The second end 72 of the second normally closed contact of contactor KM3 is connected to the first end 71 of the second normally closed contact of contactor KM4. The second end 72 of the second normally closed contact of contactor KM4 is connected to the first end 2 of the first normally open contact of auxiliary switch DL2. The second end 4 of the first normally open contact of auxiliary switch DL2 is connected to the second end D4 of the excitation winding of motor M2. The first end D3 of the excitation winding of motor M2 is connected to the first end 6 of the second normally open contact of auxiliary switch DL2. The second end 8 of the second normally open contact of auxiliary switch DL2 is connected to the second section 2 of resistor R1.

[0021] Further, the control circuit of the earthing switch can be divided into an opening control circuit of the earthing switch and a closing control circuit of the earthing switch;

[0022] The opening control circuit of the earthing switch includes contactor KM3, contactor KM4, contactor KM3, contactor KM4, earthing opening in-place travel switch CK3, earthing manual locking travel switch CK6, and auxiliary switch DL1. The first input power supply L is connected to the first end 33 of the fourth normally open contact of contactor KM3. The second end 34 of the fourth normally open contact of contactor KM3 is connected to the first end 51 of the fourth normally closed contact of contactor KM4. The first end 51 of the fourth normally closed contact of contactor KM4 is simultaneously connected to the earthing opening signal power supply. The second end 52 of the fourth normally closed contact of contactor KM4 is connected to the first end A1 of the coil of contactor KM3. The second end A2 of the coil of contactor KM3 is connected to the first end 1 of the first normally open contact of earthing opening in-place travel switch CK3. The second end 2 of the first normally open contact of earthing opening in-place travel switch CK3 is connected to the first end 1 of the first normally closed contact of earthing manual locking travel switch CK6. The second end 2 of the first normally closed contact of earthing manual locking travel switch CK6 is connected to the first end 1 of the third normally closed contact of auxiliary switch DL1. The second end 3 of the third normally closed contact of auxiliary switch DL1 is connected to the first end 61 of the fourth normally closed contact of contactor KM1. The second end 62 of the fourth normally closed contact of contactor KM1 is connected to the first end 62 of the fourth normally closed contact of contactor KM2. The second end 61 of the fourth normally closed contact of contactor KM2 is connected to the second input power supply N through an interlock condition;

[0023] The closing control circuit of the grounding switch includes contactors KM3, KM4, isolation opening-in-place travel switch CK1, grounding closing-in-place travel switch CK4, grounding manual locking travel switch CK6, and auxiliary switch DL1. The first input power supply L is connected to the first end 33 of the fourth normally open contact of contactor KM4. The second end 34 of the fourth normally open contact of contactor KM4 is connected to the first end 51 of the fourth normally closed contact of contactor KM3. The first end 51 of the fourth normally closed contact of contactor KM3 is simultaneously connected to the grounding closing signal power supply. The second end 52 of the fourth normally closed contact of contactor KM3 is connected to the first end A1 of the coil of contactor KM4. The second end A2 of the coil of contactor KM4 is connected to the first end 1 of the first normally closed contact of grounding closing-in-place travel switch CK4. The second end 2 of the first normally closed contact of grounding closing-in-place travel switch CK4 is connected to the first end 3 of the first normally closed contact of grounding opening-in-place travel switch CK3. The second end 4 of the first normally closed contact of grounding opening-in-place travel switch CK3 is connected to the first end 1 of the first normally closed contact of grounding manual locking travel switch CK6. The second end 2 of the first normally closed contact of grounding manual locking travel switch CK6 is connected to the first end 1 of the third normally closed contact of auxiliary switch DL1. The second end 3 of the third normally closed contact of auxiliary switch DL1 is connected to the first end 61 of the fourth normally closed contact of contactor KM1. The second end 62 of the fourth normally closed contact of contactor KM1 is connected to the first end 62 of the fourth normally closed contact of contactor KM2. The second end 61 of the fourth normally closed contact of contactor KM2 is connected to the second input power supply N through an interlocking condition.

[0024] Furthermore, the disconnector control circuit and the grounding switch control circuit use four contactors, six travel switches, and two auxiliary switches to achieve self-holding of the opening and closing power signals of the disconnector and the grounding switch, isolation, and electrical interlock between the disconnector and the grounding switch. It can ensure that the grounding switch cannot operate when the disconnector is closed, the disconnector cannot operate when the grounding switch is closed, the disconnector cannot be electrically operated during manual operation, and the grounding switch cannot be electrically operated during manual operation.

[0025] In the disconnector control and braking circuit and the grounding switch control and braking circuit, normally open contacts of contactors are added at both sides of the power supply, which can effectively prevent the braking circuit from being directly connected to the positive or negative pole, thus avoiding the situation of short circuit caused by parasitic circuits.

[0026] Further, the isolation closing operation mode is as follows: after the isolation closing signal is sent, the current passes through the third normally closed contact 51-52 of the contactor KM1, the coil A1-A2 of the contactor KM2, the first normally closed contact 1-2 of the isolation closing in-place travel switch CK2, the first normally closed contact 3-4 of the grounding opening in-place travel switch CK3, the first normally closed contact 1-2 of the isolation manual locking travel switch CK5, the third normally closed contact 1-3 of the auxiliary switch DL2, the third normally closed contact 61-62 of the contactor KM3, the third normally closed contact 62-61 of the contactor KM4, the interlock condition, and reaches the second voltage N. At this time, after the coil of the contactor KM2 is energized, the fourth normally open contact 33-34 of the contactor KM2 closes, and the loop self-holds. Figure 2 The normally open contact of the contactor KM2 in it closes, and the normally closed contact opens. The current passes from the first input power supply L through the first normally open contact 23-24 of the contactor KM2, the armature winding ZH1-ZH2 of the motor M1, the second normally open contact 13-14 of the contactor KM2, the field winding D3-D4 of the motor M1, and the third normally open contact 44-43 of the contactor KM2, and reaches the second input power supply N, driving the motor to rotate forward to realize the isolation closing of the three-position mechanism. After the closing is in place, Figure 3 the first normally closed contact 1-2 of the isolation closing in-place travel switch CK2 in it disconnects, and the coil of the contactor KM2 is de-energized. Figure 1 the normally open contact of KM2 in it returns to the open state, and the normally closed contact returns to the closed state. The first normally closed contact 9-11 and the second normally closed contact 5-7 of the auxiliary switch DL1 of the auxiliary switch switch to the open state, and the first normally open contact 2-4 and the second normally open contact 6-8 of the auxiliary switch DL1 switch to the closed state. At this time, the resistor R1, the first normally closed contact 82-81 of the contactor KM2, the first normally closed contact 82-81 of the contactor KM1, the armature winding ZH1-ZH2 of the motor M1, the second normally closed contact 71-72 of the contactor KM1, the second normally closed contact 71-72 of the contactor KM2, the first normally open contact 2-4 of the auxiliary switch DL1, the field winding D4-D3 of the motor M1, and the second normally open contact 6-8 of the auxiliary switch DL1 form a closed loop. At this time, the braking loop is turned on. After the auxiliary switch contacts are switched, the electromotive force in the armature winding during braking is opposite to the electromotive force in the armature winding during closing, so that the motor quickly brakes and stops rotating, and a resistor is connected in series to play a role in limiting the current.

[0027] Further, the isolation opening operation mode is as follows: after the isolation closing, the first normally open contact 1-2 of the isolation closing in-place travel switch CK1 closes. After the isolation opening signal is sent, the current passes through the third normally closed contact 51-52 of the contactor KM2, the coil A1-A2 of the contactor KM1, the first normally closed contact 1-2 of the isolation closing in-place travel switch CK1, the first normally closed contact 1-2 of the isolation manual locking travel switch CK5, the third normally closed contact 1-3 of the auxiliary switch DL2, the third normally closed contact 61-62 of the contactor KM3, the third normally closed contact 62-61 of the contactor KM4, the interlock condition, and reaches the second voltage N. At this time, after the coil of the contactor KM2 is energized, the fourth normally open contact 33-34 of the contactor KM2 closes, and the loop self-holds. The normally open contact of the contactor KM2 closes, and the normally closed contact disconnects. The current passes from the first input power supply L through the first normally open contact 23-24 of the contactor KM1, the armature winding ZH2-ZH1 of the motor M1, the second normally open contact 13-14 of the contactor KM1, the field winding D3-D4 of the motor M1, and the third normally open contact 44-43 of the contactor KM1, and reaches the second input power supply N, driving the motor to reverse, and realizing the isolation opening of the three-position mechanism; after the opening is in place, the first normally open contact 1-2 of the isolation opening in-place travel switch CK1 returns to the open state, the coil of the contactor KM1 is de-energized, the normally open contact of KM1 returns to the open state, and the normally closed contact returns to the closed state. The first normally closed contact 9-11 and the second normally closed contact 5-7 of the auxiliary switch DL1 return to the closed state. The first normally open contact 2-4 and the second normally open contact 6-8 of the auxiliary switch DL1 return to the open state. At this time, the resistor R1, the first normally closed contact 82-81 of the contactor KM2, the first normally closed contact 82-81 of the contactor KM1, the armature winding ZH1-ZH2 of the motor M1, the second normally closed contact 71-72 of the contactor KM1, the second normally closed contact 71-72 of the contactor KM2, the first normally closed contact 9-11 of the auxiliary switch DL1, the field winding D3-D4 of the motor M1, and the second normally closed contact 5-7 of the auxiliary switch DL1 form a closed loop. At this time, the braking loop is connected. After the auxiliary switch contacts are switched, the electromotive force in the armature winding during braking is opposite to the electromotive force in the armature winding during closing, so that the motor quickly brakes and stops rotating, and a resistor is connected in series to play a role in limiting the current.

[0028] Another object of the present invention is to provide a detection method for the control braking circuit of a three-position mechanism based on the control braking circuit of the three-position mechanism. The method specifically includes:

[0029] Taking the opening state of the disconnector control circuit as an example, two terminal connections are led out in the circuit, namely the first terminal 1 of terminal X1 and the first terminal 2 of terminal X1. The normal operation of the braking circuit can be judged by measuring the resistance values at the first terminal 1 and the first terminal 2 of terminal X1. Denote the resistance value of the armature winding ZH1-ZH2 of motor M1 as r1, the resistance value of the excitation winding D3-D4 of motor M1 as r2, and the resistance value of 1-2 of resistor R1 as r3. Then the theoretical resistance value at the first terminal 1 and the first terminal 2 of terminal X1 is r1×(r2 + r3) / (r1 + r2 + r3). The normal operation of the braking circuit is judged by comparing whether the measured value is consistent with the theoretical calculated value. The detection methods for the closing state of the disconnector control circuit and the opening and closing states of the earthing switch control circuit are the same and the resistance values are equal. Each state is detected once to determine whether the braking circuits in each state are normal.

[0030] Combined with the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solutions to be protected by the present invention are as follows:

[0031] First, the present invention provides a control braking circuit and its detection method for a three-position mechanism. The control braking circuit includes: a disconnector motor circuit and a braking circuit, a disconnector control circuit, an earthing switch motor circuit and a braking circuit, and an earthing switch control circuit, which can realize the forward and reverse rotations of the isolating motor and the earthing motor, and drive the three-position mechanism to realize three working states of isolating closing, opening, and earthing closing. When the disconnector and the earthing switch mechanisms are in place for opening and closing, the braking circuit is immediately put into operation, forming a closed loop with the excitation coil, the rotor winding of the motor, and the resistor. At this time, the remaining mechanical kinetic energy of the rotor can be converted into electrical energy and quickly consumed through the resistor, thus achieving a fast braking effect. Through experimental verification, compared with the case without adding a braking circuit, the linear braking distance of the mechanism can be shortened by more than half, and the braking effect is obvious. This effectively avoids mechanical jamming caused by mechanical overshoot and effectively solves the defects of difficult motor starting, overheating, or burning caused by mechanical jamming. The braking circuit realizes the sharing of the braking circuit during opening and closing, that is, when the motor rotates forward and backward, through the contact switching of components and the combination of multiple component contacts, thus realizing two-way braking. In addition, the present invention also provides a detection method. By comparing the measured resistance value of the circuit with the theoretical value, it is possible to quickly judge whether the wiring of the braking circuit is normal, greatly shortening the circuit inspection time and avoiding the hidden danger of electrical braking failure caused by an abnormal braking circuit.

[0032] Second, the expected benefits and commercial value after the transformation of the technical solution of the present invention are as follows: Since when the three-position mechanism reaches the in-place position during closing and opening, the magnitude of the mechanical overshoot is closely related to the resistance of the switch body, the motor power supply voltage, and the adjustment amount of the assembly positions such as the travel switch, etc. These quantities are all variable and not fixed, and it is difficult to achieve consistency or consistency within a small range. Therefore, the overshoot of the three-position mechanism varies in size and is difficult to adjust. As a result, defects such as motor burnout often occur during the operation of the three-position switch on-site. These defects can lead to abnormal power outages, user complaints, and also cause actual economic losses. The cost of service defect elimination is also very high. According to research estimates, the direct economic loss amounts to nearly ten million yuan, and the hidden losses are even incalculable. By adopting the solution of the present invention, only two resistors need to be added, and several contacts and several wires need to be added to the control contactor, and the cost is relatively low. Therefore, the comprehensive benefit is relatively high.

[0033] The technical solution of the present invention solves the technical problem that people have been eager to solve but have never succeeded in: The mechanical overshoot problem of the three-position switch has always troubled various switch manufacturers and power users. Many manufacturers have taken some measures, but many of the measures have poor effects or high costs. Without changing the mechanical structure, the present invention effectively solves the mechanical overshoot problem through a simple secondary circuit design, and has a good braking effect and low cost.

[0034] Third, the present invention effectively solves the problems of unreliable interlock, insufficient motor control accuracy, and low braking energy consumption efficiency existing in the control and braking circuit of the existing three-position mechanism in industrial applications. By designing the closing and opening control circuits of the disconnector and the earthing switch, and adopting the linkage mechanism of the contactor and the auxiliary switch, the reliability and synchronism of the closing and opening actions are significantly improved, and the problem of high complexity and easy failure of the interlock design in the prior art is solved.

[0035] The present invention innovatively introduces a resistor into the braking circuit. By connecting the resistor in series to consume the excess energy and limit the rapid rise of the current, the risk of circuit short-circuit that may be caused during the braking process is reduced. This design not only improves the safety of the circuit but also realizes the efficient management of electrical energy in the braking circuit, making up for the deficiency of the traditional braking method in controlling energy consumption.

[0036] For the control requirements of the forward and reverse rotation of the motor, the present invention adopts an accurate contact switching design, enabling the motor to achieve precise forward and reverse rotation actions, thereby ensuring the smooth progress of the closing and opening processes of the three-position mechanism. Through the optimized control of the forward and reverse rotation of the motor, mechanical wear and energy waste are reduced, and the problem of low efficiency caused by the lag of steering switching in the existing control system is solved.

[0037] The overall solution realizes the stable operation of the three-position mechanism in a complex electrical environment through innovative control loop and braking loop designs. Compared with the prior art, the present invention not only significantly improves the operation efficiency and safety of the system, but also provides a highly reliable and highly adaptable solution for the interlocking operation of the disconnector and the earthing switch, and has broad application prospects and technical popularization value. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 is the control and braking circuit diagram of the three-position mechanism provided by an embodiment of the present invention;

[0039] Figure 2 is the motor circuit and braking circuit diagram of the disconnector provided by an embodiment of the present invention;

[0040] Figure 3 is the control circuit diagram of the disconnector provided by an embodiment of the present invention;

[0041] Figure 4 is the motor circuit and braking circuit diagram of the earthing switch provided by an embodiment of the present invention;

[0042] Figure 5 is the control circuit diagram of the earthing switch provided by an embodiment of the present invention;

[0043] Figure 6 is the opening state of the control circuit of the disconnector provided by an embodiment of the present invention;

[0044] Figure 7 is the circuit diagram provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0045] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0046] Referring to Figure 1 , the control and braking circuit of the three-position mechanism provided by an embodiment of the present invention includes a motor circuit and a braking circuit of the disconnector, a control circuit of the disconnector, a motor circuit and a braking circuit of the earthing switch, and a control circuit of the earthing switch.

[0047] Referring to Figure 2 , the motor circuit and the braking circuit of the disconnector can be divided into a disconnector opening motor circuit, a disconnector closing motor circuit, a disconnector opening braking circuit, and a disconnector closing braking circuit.

[0048] The disconnector opening motor circuit includes a contactor KM1 and a motor M1. The first input power supply L is connected to the first end 23 of the first normally open contact of the contactor KM1. The second end 24 of the first normally open contact of the contactor KM1 is connected to the second end ZH2 of the armature winding of the motor M1. The first end ZH1 of the armature winding of the motor M1 is connected to the first end 13 of the second normally open contact of the contactor KM1. The second end 14 of the second normally open contact of the contactor KM1 is connected to the first end D3 of the excitation winding of the motor M1. The second end D4 of the excitation winding of the motor M1 is connected to the first end 44 of the third normally open contact of the contactor KM1. The second end 43 of the third normally open contact of the contactor KM1 is connected to the second input power supply N.

[0049] The disconnector closing motor circuit includes a contactor KM2 and a motor M1. The first input power supply L is connected to the first end 23 of the first normally open contact of the contactor KM2. The second end 24 of the first normally open contact of the contactor KM2 is connected to the first end ZH1 of the armature winding of the motor M1. The second end ZH2 of the armature winding of the motor M1 is connected to the first end 13 of the second normally open contact of the contactor KM2. The second end 14 of the second normally open contact of the contactor KM2 is connected to the first end D3 of the excitation winding of the motor M1. The second end D4 of the excitation winding of the motor M1 is connected to the first end 44 of the third normally open contact of the contactor KM2. The second end 43 of the third normally open contact of the contactor KM2 is connected to the second input power supply N.

[0050] The disconnector opening braking circuit includes a contactor KM1, a contactor KM2, a motor M1, a resistor R1, and an auxiliary switch DL1. The first end 1 of the resistor R1 is connected to the first end 82 of the first normally closed contact of the contactor KM2. The second end 81 of the first normally closed contact of the contactor KM2 is connected to the first end 82 of the first normally closed contact of the contactor KM1. The second end 81 of the first normally closed contact of the contactor KM1 is connected to the first end ZH1 of the armature winding of the motor M1. The second end ZH2 of the armature winding of the motor M1 is connected to the first end 71 of the second normally closed contact of the contactor KM1. The second end 72 of the second normally closed contact of the contactor KM1 is connected to the first end 71 of the second normally closed contact of the contactor KM2. The second end 72 of the second normally closed contact of the contactor KM2 is connected to the first end 9 of the first normally closed contact of the auxiliary switch DL1. The second end 11 of the first normally closed contact of the auxiliary switch DL1 is connected to the first end D3 of the excitation winding of the motor M1. The second end D4 of the excitation winding of the motor M1 is connected to the first end 5 of the second normally closed contact of the auxiliary switch DL1. The second end 7 of the second normally closed contact of the auxiliary switch DL1 is connected to the second segment 2 of the resistor R1.

[0051] The closing braking circuit of the disconnector includes contactor KM1, contactor KM2, motor M1, resistor R1, and auxiliary switch DL1. The first end 1 of resistor R1 is connected to the first end 82 of the first normally closed contact of contactor KM2. The second end 81 of the first normally closed contact of contactor KM2 is connected to the first end 82 of the first normally closed contact of contactor KM1. The second end 81 of the first normally closed contact of contactor KM1 is connected to the first end ZH1 of the armature winding of motor M1. The second end ZH2 of the armature winding of motor M1 is connected to the first end 71 of the second normally closed contact of contactor KM1. The second end 72 of the second normally closed contact of contactor KM1 is connected to the first end 71 of the second normally closed contact of contactor KM2. The second end 72 of the second normally closed contact of contactor KM2 is connected to the first end 2 of the first normally open contact of auxiliary switch DL1. The second end 4 of the first normally open contact of auxiliary switch DL1 is connected to the second end D4 of the excitation winding of motor M1. The first end D3 of the excitation winding of motor M1 is connected to the first end 6 of the second normally open contact of auxiliary switch DL1. The second end 8 of the second normally open contact of auxiliary switch DL1 is connected to the second section 2 of resistor R1.

[0052] Reference Figure 3 , the disconnector control circuit can be divided into a disconnector opening control circuit and a disconnector closing control circuit.

[0053] The disconnector opening control circuit includes contactor KM1, contactor KM2, contactor KM3, contactor KM4, disconnector opening in-place travel switch CK1, disconnector manual locking travel switch CK5, and auxiliary switch DL2. The first input power supply L is connected to the first end 33 of the fourth normally open contact of contactor KM1. The second end 34 of the fourth normally open contact of contactor KM1 is connected to the first end 51 of the third normally closed contact of contactor KM2. The first end 51 of the third normally closed contact of contactor KM2 is simultaneously connected to the disconnector opening signal power supply. The second end 52 of the third normally closed contact of contactor KM2 is connected to the first end A1 of the coil of contactor KM1. The second end A2 of the coil of contactor KM1 is connected to the first end 1 of the first normally open contact of disconnector opening in-place travel switch CK1. The second end 2 of the first normally open contact of disconnector opening in-place travel switch CK1 is connected to the first end 1 of the first normally closed contact of disconnector manual locking travel switch CK5. The second end 2 of the first normally closed contact of disconnector manual locking travel switch CK5 is connected to the first end 1 of the third normally closed contact of auxiliary switch DL2. The second end 3 of the third normally closed contact of auxiliary switch DL2 is connected to the first end 61 of the third normally closed contact of contactor KM3. The second end 62 of the third normally closed contact of contactor KM3 is connected to the first end 62 of the third normally closed contact of contactor KM4. The second end 61 of the third normally closed contact of contactor KM4 is connected to the second input power supply N through the interlock condition.

[0054] The isolating switch closing control circuit includes contactor KM1, contactor KM2, contactor KM3, contactor KM4, isolating switch closing-in place travel switch CK2, earthing switch opening-in place travel switch CK3, isolating switch manual locking travel switch CK5, and auxiliary switch DL2. The first input power supply L is connected to the first end 33 of the fourth normally open contact of contactor KM2. The second end 34 of the fourth normally open contact of contactor KM2 is connected to the first end 51 of the third normally closed contact of contactor KM1. The first end 51 of the third normally closed contact of contactor KM1 is simultaneously connected to the isolating switch closing signal power supply. The second end 52 of the third normally closed contact of contactor KM1 is connected to the first end A1 of the coil of contactor KM2. The second end A2 of the coil of contactor KM1 is connected to the first end 1 of the first normally closed contact of isolating switch closing-in place travel switch CK2. The second end 2 of the first normally closed contact of isolating switch closing-in place travel switch CK2 is connected to the first end 3 of the first normally closed contact of earthing switch opening-in place travel switch CK3. The second end 4 of the first normally closed contact of earthing switch opening-in place travel switch CK3 is connected to the first end 1 of the first normally closed contact of isolating switch manual locking travel switch CK5. The second end 2 of the first normally closed contact of isolating switch manual locking travel switch CK5 is connected to the first end 1 of the third normally closed contact of auxiliary switch DL2. The second end 3 of the third normally closed contact of auxiliary switch DL2 is connected to the first end 61 of the third normally closed contact of contactor KM3. The second end 62 of the third normally closed contact of contactor KM3 is connected to the first end 62 of the third normally closed contact of contactor KM4. The second end 61 of the third normally closed contact of contactor KM4 is connected to the second input power supply N through the interlocking condition.

[0055] Reference Figure 4 , the earthing switch motor circuit and the braking circuit can be divided into the earthing switch opening motor circuit, the earthing switch closing motor circuit, the earthing switch opening braking circuit, and the earthing switch closing braking circuit.

[0056] The earthing switch opening motor circuit includes contactor KM3 and motor M2. The first input power supply L is connected to the first end 23 of the first normally open contact of contactor KM3. The second end 24 of the first normally open contact of contactor KM3 is connected to the second end ZH2 of the armature winding of motor M2. The first end ZH1 of the armature winding of motor M2 is connected to the first end 13 of the second normally open contact of contactor KM3. The second end 14 of the second normally open contact of contactor KM3 is connected to the first end D3 of the excitation winding of motor M2. The second end D4 of the excitation winding of motor M2 is connected to the first end 44 of the third normally open contact of contactor KM3. The second end 43 of the third normally open contact of contactor KM3 is connected to the second input power supply N.

[0057] The closing motor circuit of the earthing switch includes contactor KM4 and motor M2. The first input power supply L is connected to the first end 23 of the first normally open contact of contactor KM4. The second end 24 of the first normally open contact of contactor KM4 is connected to the first end ZH1 of the armature winding of motor M2. The second end ZH2 of the armature winding of motor M2 is connected to the first end 13 of the second normally open contact of contactor KM4. The second end 14 of the second normally open contact of contactor KM4 is connected to the first end D3 of the excitation winding of motor M2. The second end D4 of the excitation winding of motor M2 is connected to the first end 44 of the third normally open contact of contactor KM4. The second end 43 of the third normally open contact of contactor KM4 is connected to the second input power supply N.

[0058] The opening braking circuit of the earthing switch includes contactor KM3, contactor KM4, motor M2, resistor R1, and auxiliary switch DL2. The first end 1 of resistor R1 is connected to the first end 82 of the first normally closed contact of contactor KM4. The second end 81 of the first normally closed contact of contactor KM4 is connected to the first end 82 of the first normally closed contact of contactor KM3. The second end 81 of the first normally closed contact of contactor KM3 is connected to the first end ZH1 of the armature winding of motor M2. The second end ZH2 of the armature winding of motor M2 is connected to the first end 71 of the second normally closed contact of contactor KM3. The second end 72 of the second normally closed contact of contactor KM3 is connected to the first end 71 of the second normally closed contact of contactor KM4. The second end 72 of the second normally closed contact of contactor KM4 is connected to the first end 9 of the first normally closed contact of auxiliary switch DL2. The second end 11 of the first normally closed contact of auxiliary switch DL2 is connected to the first end D3 of the excitation winding of motor M2. The second end D4 of the excitation winding of motor M2 is connected to the first end 5 of the second normally closed contact of auxiliary switch DL2. The second end 7 of the second normally closed contact of auxiliary switch DL2 is connected to the second section 2 of resistor R1.

[0059] The closing braking circuit of the earthing switch includes contactor KM3, contactor KM4, motor M2, resistor R1, and auxiliary switch DL2. The first end 1 of resistor R1 is connected to the first end 82 of the first normally closed contact of contactor KM4. The second end 81 of the first normally closed contact of contactor KM4 is connected to the first end 82 of the first normally closed contact of contactor KM3. The second end 81 of the first normally closed contact of contactor KM3 is connected to the first end ZH1 of the armature winding of motor M2. The second end ZH2 of the armature winding of motor M2 is connected to the first end 71 of the second normally closed contact of contactor KM3. The second end 72 of the second normally closed contact of contactor KM3 is connected to the first end 71 of the second normally closed contact of contactor KM4. The second end 72 of the second normally closed contact of contactor KM4 is connected to the first end 2 of the first normally open contact of auxiliary switch DL2. The second end 4 of the first normally open contact of auxiliary switch DL2 is connected to the second end D4 of the excitation winding of motor M2. The first end D3 of the excitation winding of motor M2 is connected to the first end 6 of the second normally open contact of auxiliary switch DL2. The second end 8 of the second normally open contact of auxiliary switch DL2 is connected to the second section 2 of resistor R1.

[0060] Reference Figure 5 , the control circuit of the earthing switch can be divided into the opening control circuit of the earthing switch and the closing control circuit of the earthing switch.

[0061] The opening control circuit of the earthing switch includes contactor KM3, contactor KM4, contactor KM3, contactor KM4, earthing opening in-place travel switch CK3, earthing manual locking travel switch CK6, and auxiliary switch DL1. The first input power supply L is connected to the first end 33 of the fourth normally open contact of contactor KM3. The second end 34 of the fourth normally open contact of contactor KM3 is connected to the first end 51 of the fourth normally closed contact of contactor KM4. The first end 51 of the fourth normally closed contact of contactor KM4 is simultaneously connected to the earthing opening signal power supply. The second end 52 of the fourth normally closed contact of contactor KM4 is connected to the first end A1 of the coil of contactor KM3. The second end A2 of the coil of contactor KM3 is connected to the first end 1 of the first normally open contact of earthing opening in-place travel switch CK3. The second end 2 of the first normally open contact of earthing opening in-place travel switch CK3 is connected to the first end 1 of the first normally closed contact of earthing manual locking travel switch CK6. The second end 2 of the first normally closed contact of earthing manual locking travel switch CK6 is connected to the first end 1 of the third normally closed contact of auxiliary switch DL1. The second end 3 of the third normally closed contact of auxiliary switch DL1 is connected to the first end 61 of the fourth normally closed contact of contactor KM1. The second end 62 of the fourth normally closed contact of contactor KM1 is connected to the first end 62 of the fourth normally closed contact of contactor KM2. The second end 61 of the fourth normally closed contact of contactor KM2 is connected to the second input power supply N through the interlock condition.

[0062] The closing control circuit of the earthing switch includes contactors KM3, KM4, isolation opening-in-place travel switch CK1, earthing closing-in-place travel switch CK4, earthing manual locking travel switch CK6, and auxiliary switch DL1. The first input power supply L is connected to the first end 33 of the fourth normally open contact of contactor KM4. The second end 34 of the fourth normally open contact of contactor KM4 is connected to the first end 51 of the fourth normally closed contact of contactor KM3. The first end 51 of the fourth normally closed contact of contactor KM3 is simultaneously connected to the earthing closing signal power supply. The second end 52 of the fourth normally closed contact of contactor KM3 is connected to the first end A1 of the coil of contactor KM4. The second end A2 of the coil of contactor KM4 is connected to the first end 1 of the first normally closed contact of earthing closing-in-place travel switch CK4. The second end 2 of the first normally closed contact of earthing closing-in-place travel switch CK4 is connected to the first end 3 of the first normally closed contact of earthing opening-in-place travel switch CK3. The second end 4 of the first normally closed contact of earthing opening-in-place travel switch CK3 is connected to the first end 1 of the first normally closed contact of earthing manual locking travel switch CK6. The second end 2 of the first normally closed contact of earthing manual locking travel switch CK6 is connected to the first end 1 of the third normally closed contact of auxiliary switch DL1. The second end 3 of the third normally closed contact of auxiliary switch DL1 is connected to the first end 61 of the fourth normally closed contact of contactor KM1. The second end 62 of the fourth normally closed contact of contactor KM1 is connected to the first end 62 of the fourth normally closed contact of contactor KM2. The second end 61 of the fourth normally closed contact of contactor KM2 is connected to the second input power supply N through an interlock condition.

[0063] Travel switch CK1 is an isolation opening-in-place travel switch. When the mechanism is in the isolation opening position, the first normally open contact 1-2 of travel switch CK1 is disconnected, and the first normally closed contact 3-4 of travel switch CK1 is closed. When the mechanism is in the isolation closing position, the first normally open contact 1-2 of travel switch CK1 is closed, and the first normally closed contact 3-4 of travel switch CK1 is disconnected.

[0064] Travel switch CK2 is an isolation closing-in-place travel switch. When the mechanism is in the isolation opening position, the first normally closed contact 1-2 of travel switch CK2 is closed. When the mechanism is in the isolation closing position, the first normally closed contact 1-2 of travel switch CK2 is disconnected.

[0065] Travel switch CK3 is an earthing opening-in-place travel switch. When the mechanism is in the earthing opening position, the first normally open contact 1-2 of travel switch CK3 is disconnected, and the first normally closed contact 3-4 of travel switch CK3 is closed. When the mechanism is in the earthing closing position, the first normally open contact 1-2 of travel switch CK3 is closed, and the first normally closed contact 3-4 of travel switch CK3 is disconnected.

[0066] The travel switch CK4 is the travel switch for the in-place closing of the grounding switch. When the mechanism is in the grounding opening position, the first normally closed contact 1-2 of the travel switch CK4 is closed; when the mechanism is in the grounding closing position, the first normally closed contact 1-2 of the travel switch CK4 is opened.

[0067] The travel switch CK5 is the travel switch for the isolation manual interlock. When the manual operating handle on the isolation side of the mechanism is inserted, the first normally closed contact 1-2 of the travel switch CK5 is opened; when the manual operating handle on the isolation side of the mechanism is not inserted, the first normally closed contact 1-2 of the travel switch CK5 is closed.

[0068] The travel switch CK6 is the travel switch for the grounding manual interlock. When the manual operating handle on the grounding side of the mechanism is inserted, the first normally closed contact 1-2 of the travel switch CK6 is opened; when the manual operating handle on the grounding side of the mechanism is not inserted, the first normally closed contact 1-2 of the travel switch CK6 is closed.

[0069] The auxiliary switch DL1 is the auxiliary switch for the isolation side. When the mechanism is in the isolation opening position, the odd-numbered pairs of contacts are closed and the even-numbered pairs of contacts are opened, that is, the first normally open contact 2-4 of the auxiliary switch DL1 is opened, the second normally open contact 6-8 of the auxiliary switch DL1 is opened, the first normally closed contact 9-11 of the auxiliary switch DL1 is closed, the second normally closed contact 5-7 of the auxiliary switch DL1 is closed, and the third normally closed contact 1-3 of the auxiliary switch DL1 is closed; when the mechanism is in the isolation closing position, the odd-numbered pairs of contacts are opened and the even-numbered pairs of contacts are closed, that is, the first normally open contact 2-4 of the auxiliary switch DL1 is closed, the second normally open contact 6-8 of the auxiliary switch DL1 is closed, the first normally closed contact 9-11 of the auxiliary switch DL1 is opened, the second normally closed contact 5-7 of the auxiliary switch DL1 is opened, and the third normally closed contact 1-3 of the auxiliary switch DL1 is opened.

[0070] The auxiliary switch DL2 is the auxiliary switch for the grounding side. When the mechanism is in the grounding opening position, the odd-numbered pairs of contacts are closed and the even-numbered pairs of contacts are opened, that is, the first normally open contact 2-4 of the auxiliary switch DL2 is opened, the second normally open contact 6-8 of the auxiliary switch DL2 is opened, the first normally closed contact 9-11 of the auxiliary switch DL2 is closed, the second normally closed contact 5-7 of the auxiliary switch DL2 is closed, and the third normally closed contact 1-3 of the auxiliary switch DL2 is closed; when the mechanism is in the grounding closing position, the odd-numbered pairs of contacts are opened and the even-numbered pairs of contacts are closed, that is, the first normally open contact 2-4 of the auxiliary switch DL2 is closed, the second normally open contact 6-8 of the auxiliary switch DL2 is closed, the first normally closed contact 9-11 of the auxiliary switch DL2 is opened, the second normally closed contact 5-7 of the auxiliary switch DL2 is opened, and the third normally closed contact 1-3 of the auxiliary switch DL2 is opened.

[0071] The specific working mode is as follows:

[0072] Taking the disconnector as an example for introduction, the operating mode of the earthing switch is the same as that of the disconnector, so it will not be elaborated here.

[0073] Isolation closing: Refer to Figure 3 , after the isolation closing signal is sent out, the current passes through the third normally closed contact 51-52 of the contactor KM1, the coil A1-A2 of the contactor KM2, the first normally closed contact 1-2 of the isolation closing in-place travel switch CK2, the first normally closed contact 3-4 of the earthing opening in-place travel switch CK3, the first normally closed contact 1-2 of the isolation manual locking travel switch CK5, the third normally closed contact 1-3 of the auxiliary switch DL2, the third normally closed contact 61-62 of the contactor KM3, the third normally closed contact 62-61 of the contactor KM4, the interlocking condition, and reaches the second voltage N. At this time, after the coil of the contactor KM2 is energized, the fourth normally open contact 33-34 of the contactor KM2 closes, and the loop self-holds. Figure 2 In , the normally open contact of the contactor KM2 closes and the normally closed contact opens. The current passes from the first input power supply L through the first normally open contact 23-24 of the contactor KM2, the armature winding ZH1-ZH2 of the motor M1, the second normally open contact 13-14 of the contactor KM2, the excitation winding D3-D4 of the motor M1, and the third normally open contact 44-43 of the contactor KM2, and reaches the second input power supply N, driving the motor to rotate forward to realize the isolation closing of the three-position mechanism. After closing in place, Figure 3 in , the first normally closed contact 1-2 of the isolation closing in-place travel switch CK2 disconnects, and the coil of the contactor KM2 is de-energized. Figure 1 in , the normally open contact of KM2 returns to the open state, and the normally closed contact returns to the closed state. The first normally closed contact 9-11 and the second normally closed contact 5-7 of the auxiliary switch DL1 of the auxiliary switch switch to the open state, and the first normally open contact 2-4 and the second normally open contact 6-8 of the auxiliary switch DL1 switch to the closed state. At this time, the resistor R1, the first normally closed contact 82-81 of the contactor KM2, the first normally closed contact 82-81 of the contactor KM1, the armature winding ZH1-ZH2 of the motor M1, the second normally closed contact 71-72 of the contactor KM1, the second normally closed contact 71-72 of the contactor KM2, the first normally open contact 2-4 of the auxiliary switch DL1, the excitation winding D4-D3 of the motor M1, and the second normally open contact 6-8 of the auxiliary switch DL1 form a closed loop. At this time, the braking circuit is connected. After the auxiliary switch contacts are switched, the electromotive force in the armature winding during braking is opposite to the electromotive force in the armature winding during closing, so that the motor quickly brakes and stops rotating, and a resistor is connected in series to play a role in limiting the current.

[0074] Isolation opening: Refer to Figure 3, after the isolating switch is closed, the first normally open contact 1-2 of the isolating switch closing-in travel switch CK1 closes. After the isolating switch opening signal is sent, the current passes through the third normally closed contact 51-52 of the contactor KM2, the coil A1-A2 of the contactor KM1, the first normally closed contact 1-2 of the isolating switch closing-in travel switch CK1, the first normally closed contact 1-2 of the isolating switch manual locking travel switch CK5, the third normally closed contact 1-3 of the auxiliary switch DL2, the third normally closed contact 61-62 of the contactor KM3, the third normally closed contact 62-61 of the contactor KM4, the interlocking condition, and reaches the second voltage N. At this time, after the coil of the contactor KM2 is energized, the fourth normally open contact 33-34 of the contactor KM2 closes, and the loop self-holds. Figure 2 In it, the normally open contact of the contactor KM2 closes and the normally closed contact opens. The current passes from the first input power supply L through the first normally open contact 23-24 of the contactor KM1, the armature winding ZH2-ZH1 of the motor M1, the second normally open contact 13-14 of the contactor KM1, the field winding D3-D4 of the motor M1, and the third normally open contact 44-43 of the contactor KM1, and reaches the second input power supply N, driving the motor to reverse and realizing the isolating switch opening of the three-position mechanism. After the opening is in place, Figure 3 In it, the first normally open contact 1-2 of the isolating switch opening-in travel switch CK1 returns to the open state, and the coil of the contactor KM1 is de-energized. Figure 1 In it, the normally open contact of KM1 returns to the open state, and the normally closed contact returns to the closed state. The first normally closed contact 9-11 and the second normally closed contact 5-7 of the auxiliary switch DL1 of the auxiliary switch return to the closed state. The first normally open contact 2-4 and the second normally open contact 6-8 of the auxiliary switch DL1 of the auxiliary switch return to the open state. At this time, the resistor R1, the first normally closed contact 82-81 of the contactor KM2, the first normally closed contact 82-81 of the contactor KM1, the armature winding ZH1-ZH2 of the motor M1, the second normally closed contact 71-72 of the contactor KM1, the second normally closed contact 71-72 of the contactor KM2, the first normally closed contact 9-11 of the auxiliary switch DL1, the field winding D3-D4 of the motor M1, and the second normally closed contact 5-7 of the auxiliary switch DL1 form a closed loop. At this time, the braking loop is connected. After the auxiliary switch contacts are switched, the electromotive force in the armature winding during braking is opposite to the electromotive force in the armature winding during closing, making the motor quickly brake and stop rotating, and a resistor is connected in series to play a role in limiting the current.

[0075] In the disconnector motor circuit, normally open contacts of contactors are added on both sides of the power supply. One end of the first input power supply L is provided with the first normally open contacts 23-24 of contactor KM1 and the first normally open contacts 23-24 of contactor KM2. On one side of the second input power supply L, the third normally open contacts 44-43 of contactor KM1 and the third normally open contacts 44-43 of contactor KM2 are provided, which can effectively prevent the braking circuit from being directly connected to the positive or negative pole, and avoid the situation of short circuit caused by parasitic circuits.

[0076] Four pairs of contacts of the auxiliary switch are connected in series in the disconnector braking circuit, namely the first normally closed contact 9-11 of auxiliary switch DL1, the second normally closed contact 5-7 of auxiliary switch DL1, the first normally open contact 2-4 of auxiliary switch DL1, and the second normally open contact 6-8 of auxiliary switch DL1. Since the auxiliary switch is mechanically connected to the three-position mechanism, compared with using contactor contacts and other methods, the contact conversion is more reliable.

[0077] In the disconnector closing control circuit, the first normally closed contact 3-4 of the grounding disconnection in-place travel switch CK3 and the third normally closed contact 1-3 of the auxiliary switch DL2 are connected in series for electrical interlocking to ensure that the isolation closing operation can only be carried out when the grounding is in the open position. The auxiliary switch and the travel switch play a dual-insurance role, making the motor interlock more reliable and preventing misoperation.

[0078] The first normally closed contact 1-2 of the manual locking travel switch CK5 is connected in series in the disconnector control circuit to ensure that electric opening and closing cannot be performed during manual operation, thus ensuring the personal safety of the operator.

[0079] The third normally closed contact 61-62 of contactor KM3 and the third normally closed contact 62-61 of contactor KM4 are connected in series in the disconnector control circuit, which can ensure that isolation and grounding cannot be electrically operated simultaneously, preventing misoperation.

[0080] The present invention provides a detection method for a braking circuit, and the implementation method is as follows:

[0081] Taking the open state of the disconnector control circuit as an example, refer to Figure 6 , two terminal wirings are led out in the circuit, namely the first end 1 of terminal X1 and the first end 2 of terminal X1. The normalcy of the braking circuit can be judged by measuring the resistance values at the first end 1 of terminal X1 and the first end 2 of terminal X1. The circuit diagram can be simplified as Figure 7。Denote the resistance value of the armature winding ZH1-ZH2 of the motor M1 as r1, the resistance value of the field winding D3-D4 of the motor M1 as r2, and the resistance value of 1-2 of the resistor R1 as r3. Then the theoretical resistance value at the first terminal 1 and the first terminal 2 of the terminal X1 is r1×(r2+r3) / (r1+r2+r3). It is judged whether the braking circuit is normal by comparing whether the measured value is consistent with the theoretical calculated value. The detection methods for the closing state of the disconnector control circuit and the closing and opening states of the earthing switch closing and opening control circuit are the same and the resistance values are equal. It is only necessary to detect each state once to determine whether the braking circuits of each state are normal, and the specific description will not be repeated here.

[0082] The present invention is mainly used for the three-position switch mechanism of high-voltage combined electrical appliances, and can also be used for two-position switch mechanisms, or for other occasions where it is required to brake the AC / DC dual-use motor after power-off, solving the big problem of large inertial overshoot after the motor is powered off, thereby preventing potential hazards caused by mechanical motion inertial overshoot.

[0083] In the embodiment of the present invention, by testing the opening and closing actions of the disconnector, the significant effect of the braking circuit on improving the control accuracy is verified. In the case of isolating closing, the manually operated measured switching distance of the travel switch is 42 mm, the measured average stop distance of the electric operation is 37.85 mm, and the braking distance is 4.15 mm. Compared with the case without using the braking circuit, the average stop distance of the electric operation is 31.5 mm, and the braking distance is 10.5 mm. By adding the braking circuit, the overshoot distance is reduced by 6.35 mm, significantly improving the action accuracy and control stability.

[0084] In the test of isolating opening, the manually operated switching distance of the travel switch is 70 mm, the measured average stop distance of the electric operation is 63.05 mm, and the braking distance is 6.95 mm. Without using the braking circuit, the average stop distance of the electric operation is 57.88 mm, and the braking distance is 12.12 mm. By adding the braking circuit, the overshoot distance is reduced by 5.17 mm, further verifying the effect of the braking circuit in reducing the action overshoot and improving the opening accuracy.

[0085] The test results show that by adding the braking circuit, the present invention effectively reduces the overshoot distance during the operation of the disconnector. Whether in the closing or opening operation, it shows higher accuracy and stability. This improvement not only optimizes the operation performance of the disconnector, but also significantly reduces mechanical wear and action errors, improving the reliability of the system.

[0086] In addition, the verification results of this embodiment also illustrate the advantages of the present invention in practical applications. Through precise braking control, the system can achieve stable operation in a complex electrical environment, providing an efficient and reliable solution for similar switch control systems, and having broad engineering value and industrial application prospects.

[0087]

[0088]

[0089] As described above, the above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention should be covered by the protection scope of the present invention.

Claims

1. A control brake circuit for a three-station mechanism, characterized in that: The core essential technical features of the present invention include: constructing a control and braking circuit for the isolating switch and the grounding switch through a combination of a contactor and an auxiliary switch; the control circuit includes a travel switch to detect the opening and closing status, and realizes the forward and reverse control of the motor by switching the normally open and normally closed contacts of the contactor; a resistor is connected in series in the braking circuit to limit the current and consume excess energy; the entire circuit realizes the opening and closing interlocking of the isolating switch and the grounding switch through the linkage design of multiple groups of normally closed and normally open contacts, forming a precise control logic for a continuous electrical circuit.

2. The control brake circuit of the three-station mechanism according to claim 1 is characterized in that: The isolating switch motor circuit and brake circuit can be divided into an isolating switch opening motor circuit, an isolating switch closing motor circuit, an isolating switch opening brake circuit, and an isolating switch closing brake circuit; The disconnector opening motor circuit includes a contactor KM1 and a motor M1, a first input power supply L is connected to a first end 23 of a first normally open contact of the contactor KM1, a second end 24 of the first normally open contact of the contactor KM1 is connected to a second end ZH2 of an armature winding of the motor M1, a first end ZH1 of the armature winding of the motor M1 is connected to a first end 13 of a second normally open contact of the contactor KM1, a second end 14 of the second normally open contact of the contactor KM1 is connected to a first end D3 of an excitation winding of the motor M1, a second end D4 of an excitation winding of the motor M1 is connected to a first end 44 of a third normally open contact of the contactor KM1, and a second end 43 of the third normally open contact of the contactor KM1 is connected to a second input power supply N; The isolating switch closing motor circuit includes a contactor KM2 and a motor M1, a first input power supply L is connected to a first end 23 of a first normally open contact of the contactor KM2, a second end 24 of the first normally open contact of the contactor KM2 is connected to a first end ZH1 of an armature winding of the motor M1, a second end ZH2 of the armature winding of the motor M1 is connected to a first end 13 of a second normally open contact of the contactor KM2, a second end 14 of the second normally open contact of the contactor KM2 is connected to a first end D3 of an excitation winding of the motor M1, a second end D4 of an excitation winding of the motor M1 is connected to a first end 44 of a third normally open contact of the contactor KM2, and a second end 43 of the third normally open contact of the contactor KM2 is connected to a second input power supply N; The disconnector opening brake circuit includes a contactor KM1, a contactor KM2, a motor M1, a resistor R1, and an auxiliary switch DL1. The first end 1 of the resistor R1 is connected to the first end 82 of the first normally closed contact of the contactor KM2, the second end 81 of the first normally closed contact of the contactor KM2 is connected to the first end 82 of the first normally closed contact of the contactor KM1, the second end 81 of the first normally closed contact of the contactor KM1 is connected to the first end ZH1 of the armature winding of the motor M1, the second end ZH2 of the armature winding of the motor M1 is connected to the first end 71 of the second normally closed contact of the contactor KM1. The second end 72 of the second normally closed contact of the contactor KM1 is connected to the first end 71 of the second normally closed contact of the contactor KM2, the second end 72 of the second normally closed contact of the contactor KM2 is connected to the first end 9 of the first normally closed contact of the auxiliary switch DL1, the second end 11 of the first normally closed contact of the auxiliary switch DL1 is connected to the first end D3 of the excitation winding of the motor M1, the second end D4 of the excitation winding of the motor M1 is connected to the first end 5 of the second normally closed contact of the auxiliary switch DL1, and the second end 7 of the second normally closed contact of the auxiliary switch DL1 is connected to the second section 2 of the resistor R1; The isolating switch closing brake circuit includes a contactor KM1, a contactor KM2, a motor M1, a resistor R1, and an auxiliary switch DL1. The first end 1 of the resistor R1 is connected to the first end 82 of the first normally closed contact of the contactor KM2, the second end 81 of the first normally closed contact of the contactor KM2 is connected to the first end 82 of the first normally closed contact of the contactor KM1, the second end 81 of the first normally closed contact of the contactor KM1 is connected to the first end ZH1 of the armature winding of the motor M1, and the second end ZH2 of the armature winding of the motor M1 is connected to the first end 7 of the second normally closed contact of the contactor KM1. 1, the second end 72 of the second normally closed contact of contactor KM1 is connected to the first end 71 of the second normally closed contact of contactor KM2, the second end 72 of the second normally closed contact of contactor KM2 is connected to the first end 2 of the first normally open contact of auxiliary switch DL1, the second end 4 of the first normally open contact of auxiliary switch DL1 is connected to the second end D4 of the excitation winding of motor M1, the first end D3 of the excitation winding of motor M1 is connected to the first end 6 of the second normally open contact of auxiliary switch DL1, and the second end 8 of the second normally open contact of auxiliary switch DL1 is connected to the second section 2 of resistor R1.

3. The control brake circuit of the three-station mechanism according to claim 1, characterized in that: The isolating switch motor circuit and brake circuit control an AC / DC dual-purpose motor through two contactors for forward and reverse rotation to realize the opening and closing action of the isolating switch; the motor is controlled to brake through two contactors and an auxiliary switch, and a resistor is connected in series to consume energy and limit current.

4. The control brake circuit of the three-station mechanism according to claim 1, characterized in that: The isolating switch control circuit can be divided into an isolating switch opening control circuit and an isolating switch closing control circuit; The isolating switch opening control circuit includes contactor KM1, contactor KM2, contactor KM3, contactor KM4, isolating switch in place travel switch CK1, isolating manual locking travel switch CK5, and auxiliary switch DL2. The first input power supply L is connected to the first end 33 of the fourth normally open contact of contactor KM1, the second end 34 of the fourth normally open contact of contactor KM1 is connected to the first end 51 of the third normally closed contact of contactor KM2, the first end 51 of the third normally closed contact of contactor KM2 is also connected to the isolating switch signal power supply, the second end 52 of the third normally closed contact of contactor KM2 is connected to the first end A1 of the coil of contactor KM1, and the second end A2 of the coil of contactor KM1 is connected to the isolating switch in place. The first end 1 of the first normally open contact of the travel switch CK1 is connected, the second end 2 of the first normally open contact of the isolating opening position travel switch CK1 is connected to the first end 1 of the first normally closed contact of the isolating manual locking travel switch CK5, the second end 2 of the first normally closed contact of the isolating manual locking travel switch CK5 is connected to the first end 1 of the third normally closed contact of the auxiliary switch DL2, the second end 3 of the third normally closed contact of the auxiliary switch DL2 is connected to the first end 61 of the third normally closed contact of the contactor KM3, the second end 62 of the third normally closed contact of the contactor KM3 is connected to the first end 62 of the third normally closed contact of the contactor KM4, and the second end 61 of the third normally closed contact of the contactor KM4 is connected to the second input power supply N through an interlocking condition; The isolating switch closing control circuit includes contactor KM1, contactor KM2, contactor KM3, contactor KM4, isolating closing position travel switch CK2, grounding opening position travel switch CK3, isolating manual locking travel switch CK5, and auxiliary switch DL2. The first input power supply L is connected to the first end 33 of the fourth normally open contact of contactor KM2, the second end 34 of the fourth normally open contact of contactor KM2 is connected to the first end 51 of the third normally closed contact of contactor KM1, the first end 51 of the third normally closed contact of contactor KM1 is also connected to the isolating closing signal power supply, the second end 52 of the third normally closed contact of contactor KM1 is connected to the first end A1 of the coil of contactor KM2, the second end A2 of the coil of contactor KM1 is connected to the first end 1 of the first normally closed contact of the isolating closing position travel switch CK2, and the second end A3 of the coil of contactor KM1 is connected to the first end 1 of the first normally closed contact of the isolating closing position travel switch CK2. The second end 2 of the first normally closed contact of the isolating closing position travel switch CK2 is connected with the first end 3 of the first normally closed contact of the earthing opening position travel switch CK3, the second end 4 of the first normally closed contact of the earthing opening position travel switch CK3 is connected with the first end 1 of the first normally closed contact of the isolating manual locking position travel switch CK5, the second end 2 of the first normally closed contact of the isolating manual locking position switch CK5 is connected with the first end 1 of the third normally closed contact of the auxiliary switch DL2, the second end 3 of the third normally closed contact of the auxiliary switch DL2 is connected with the first end 61 of the third normally closed contact of the contactor KM3, the second end 62 of the third normally closed contact of the contactor KM3 is connected with the first end 62 of the third normally closed contact of the contactor KM4, and the second end 61 of the third normally closed contact of the contactor KM4 is connected to the second input power supply N through interlocking conditions.

5. The control brake circuit of the three-station mechanism as claimed in claim 1, characterized in that: The grounding switch motor circuit and brake circuit can be divided into a grounding switch opening motor circuit, a grounding switch closing motor circuit, a grounding switch opening brake circuit, and a grounding switch closing brake circuit; The grounding switch motor circuit and brake circuit control an AC / DC dual-purpose motor through two contactors to rotate forward and reverse, thereby realizing the opening and closing action of the grounding switch; the motor is controlled to brake through two contactors and an auxiliary switch, and a resistor is connected in series to consume energy and limit the current; The grounding switch opening motor circuit includes a contactor KM3 and a motor M2, a first input power supply L is connected to a first end 23 of a first normally open contact of the contactor KM3, a second end 24 of the first normally open contact of the contactor KM3 is connected to a second end ZH2 of an armature winding of the motor M2, a first end ZH1 of an armature winding of the motor M2 is connected to a first end 13 of a second normally open contact of the contactor KM3, a second end 14 of the second normally open contact of the contactor KM3 is connected to a first end D3 of an excitation winding of the motor M2, a second end D4 of an excitation winding of the motor M2 is connected to a first end 44 of a third normally open contact of the contactor KM3, and a second end 43 of the third normally open contact of the contactor KM3 is connected to a second input power supply N; The grounding switch closing motor circuit includes a contactor KM4 and a motor M2, a first input power supply L is connected to a first end 23 of a first normally open contact of the contactor KM4, a second end 24 of the first normally open contact of the contactor KM4 is connected to a first end ZH1 of an armature winding of the motor M2, a second end ZH2 of the armature winding of the motor M2 is connected to a first end 13 of a second normally open contact of the contactor KM4, a second end 14 of the second normally open contact of the contactor KM4 is connected to a first end D3 of an excitation winding of the motor M2, a second end D4 of an excitation winding of the motor M2 is connected to a first end 44 of a third normally open contact of the contactor KM4, and a second end 43 of the third normally open contact of the contactor KM4 is connected to a second input power supply N; The grounding switch opening brake circuit includes a contactor KM3, a contactor KM4, a motor M2, a resistor R1, and an auxiliary switch DL2. The first end 1 of the resistor R1 is connected to the first end 82 of the first normally closed contact of the contactor KM4, the second end 81 of the first normally closed contact of the contactor KM4 is connected to the first end 82 of the first normally closed contact of the contactor KM3, the second end 81 of the first normally closed contact of the contactor KM3 is connected to the first end ZH1 of the armature winding of the motor M2, the second end ZH2 of the armature winding of the motor M2 is connected to the first end 71 of the second normally closed contact of the contactor KM3. The second end 72 of the second normally closed contact of the contactor KM3 is connected to the first end 71 of the second normally closed contact of the contactor KM4, the second end 72 of the second normally closed contact of the contactor KM4 is connected to the first end 9 of the first normally closed contact of the auxiliary switch DL2, the second end 11 of the first normally closed contact of the auxiliary switch DL2 is connected to the first end D3 of the excitation winding of the motor M2, the second end D4 of the excitation winding of the motor M2 is connected to the first end 5 of the second normally closed contact of the auxiliary switch DL2, and the second end 7 of the second normally closed contact of the auxiliary switch DL2 is connected to the second section 2 of the resistor R1; The grounding switch closing brake circuit includes a contactor KM3, a contactor KM4, a motor M2, a resistor R1, and an auxiliary switch DL2. The first end 1 of the resistor R1 is connected to the first end 82 of the first normally closed contact of the contactor KM4, the second end 81 of the first normally closed contact of the contactor KM4 is connected to the first end 82 of the first normally closed contact of the contactor KM3, the second end 81 of the first normally closed contact of the contactor KM3 is connected to the first end ZH1 of the armature winding of the motor M2, the second end ZH2 of the armature winding of the motor M2 is connected to the first end 71 of the second normally closed contact of the contactor KM3. The second end 72 of the second normally closed contact of contactor KM3 is connected to the first end 71 of the second normally closed contact of contactor KM4, the second end 72 of the second normally closed contact of contactor KM4 is connected to the first end 2 of the first normally open contact of auxiliary switch DL2, the second end 4 of the first normally open contact of auxiliary switch DL2 is connected to the second end D4 of the excitation winding of motor M2, the first end D3 of the excitation winding of motor M2 is connected to the first end 6 of the second normally open contact of auxiliary switch DL2, and the second end 8 of the second normally open contact of auxiliary switch DL2 is connected to the second section 2 of resistor R1.

6. The control brake circuit of the three-station mechanism as claimed in claim 1, characterized in that: The grounding switch control circuit can be divided into a grounding switch opening control circuit and a grounding switch closing control circuit; The grounding switch opening control circuit includes contactor KM3, contactor KM4, contactor KM3, contactor KM4, grounding opening position travel switch CK3, grounding manual locking travel switch CK6, auxiliary switch DL1, the first input power supply L is connected to the first end 33 of the fourth normally open contact of contactor KM3, the second end 34 of the fourth normally open contact of contactor KM3 is connected to the first end 51 of the fourth normally closed contact of contactor KM4, the first end 51 of the fourth normally closed contact of contactor KM4 is also connected to the grounding opening signal power supply, the second end 52 of the fourth normally closed contact of contactor KM4 is connected to the first end A1 of the coil of contactor KM3, the second end A2 of the coil of contactor KM3 is connected to the grounding opening position signal power supply, The first end 1 of the first normally open contact of the travel switch CK3 is connected, the second end 2 of the first normally open contact of the grounding opening travel switch CK3 is connected to the first end 1 of the first normally closed contact of the grounding manual locking travel switch CK6, the second end 2 of the first normally closed contact of the grounding manual locking travel switch CK6 is connected to the first end 1 of the third normally closed contact of the auxiliary switch DL1, the second end 3 of the third normally closed contact of the auxiliary switch DL1 is connected to the first end 61 of the fourth normally closed contact of the contactor KM1, the second end 62 of the fourth normally closed contact of the contactor KM1 is connected to the first end 62 of the fourth normally closed contact of the contactor KM2, and the second end 61 of the fourth normally closed contact of the contactor KM2 is connected to the second input power supply N through an interlocking condition; The grounding switch closing control circuit includes contactor KM3, contactor KM4, contactor KM3, contactor KM4, isolation and opening position travel switch CK1, grounding closing position travel switch CK4, grounding manual locking travel switch CK6, and auxiliary switch DL1. The first input power supply L is connected to the first end 33 of the fourth normally open contact of contactor KM4, the second end 34 of the fourth normally open contact of contactor KM4 is connected to the first end 51 of the fourth normally closed contact of contactor KM3, the first end 51 of the fourth normally closed contact of contactor KM3 is also connected to the grounding closing signal power supply, the second end 52 of the fourth normally closed contact of contactor KM3 is connected to the first end A1 of the coil of contactor KM4, the second end A2 of the coil of contactor KM4 is connected to the first end 1 of the first normally closed contact of the grounding closing position travel switch CK4, and the second end A3 of the coil of contactor KM4 is connected to the first end 1 of the first normally closed contact of the grounding closing position travel switch CK4. The second end 2 of the first normally closed contact of the grounding closing position travel switch CK4 is connected to the first end 3 of the first normally closed contact of the grounding opening position travel switch CK3, the second end 4 of the first normally closed contact of the grounding opening position travel switch CK3 is connected to the first end 1 of the first normally closed contact of the grounding manual locking travel switch CK6, the second end 2 of the first normally closed contact of the grounding manual locking travel switch CK6 is connected to the first end 1 of the third normally closed contact of the auxiliary switch DL1, the second end 3 of the third normally closed contact of the auxiliary switch DL1 is connected to the first end 61 of the fourth normally closed contact of the contactor KM1, the second end 62 of the fourth normally closed contact of the contactor KM1 is connected to the first end 62 of the fourth normally closed contact of the contactor KM2, and the second end 61 of the fourth normally closed contact of the contactor KM2 is connected to the second input power supply N through interlocking conditions.

7. The control brake circuit of the three-station mechanism as claimed in claim 1, characterized in that: The isolating switch control circuit and the grounding switch control circuit realize the self-maintenance of the opening and closing power supply signals of the isolating switch and the grounding switch and the electrical interlocking between the isolation and the grounding through four contactors, six travel switches and two auxiliary switches, so that the grounding switch cannot be operated when the isolation is closed, the isolating switch cannot be operated when the grounding switch is closed, the isolating switch cannot be operated electrically when the isolating switch is manually operated, and the grounding switch cannot be operated electrically when the grounding switch is manually operated; The isolating switch control and braking circuit and the grounding switch control and braking circuit add normally open contacts of the contactors at both power sources, which can effectively prevent the braking circuit from being directly connected to the positive or negative pole, generating a parasitic circuit and causing a short circuit.

8. The control brake circuit of the three-station mechanism as claimed in claim 7, characterized in that: The isolation closing working mode is: after the isolation closing signal is sent, the current passes through the third normally closed contact 51-52 of contactor KM1, the coil A1-A2 of contactor KM2, the first normally closed contact 1-2 of the isolation closing limit switch CK2, the first normally closed contact 3-4 of the grounding opening limit switch CK3, the first normally closed contact 1-2 of the isolation manual locking limit switch CK5, the third normally closed contact 1-3 of the auxiliary switch DL2, the third normally closed contact 61-62 of contactor KM3, the third normally closed contact 62-61 of contactor KM4, the interlocking condition, and reaches the second voltage N. At this time, after the coil of contactor KM2 is energized, the fourth normally open contact 33-34 of contactor KM2 is closed, and the circuit is self-maintained. In Figure 2, the normally open contact of contactor KM2 is closed and the normally closed contact is opened. The current flows from the first input power supply L through the first normally open contact 23-24 of contactor KM2, the armature winding ZH1-ZH2 of motor M1, the second normally open contact 13-14 of contactor KM2, the excitation winding D3-D4 of motor M1, and the third normally open contact 44-43 of contactor KM2 to reach the second input power supply N, driving the motor to rotate forward and realizing the isolation and closing of the three-position mechanism. After the switch is fully closed, the first normally closed contact 1-2 of the isolating and fully closed travel switch CK2 in Figure 3 is disconnected, the contactor KM2 coil is de-energized, the normally open contact of KM2 in Figure 1 is restored to the open state, the normally closed contact is restored to the closed state, the first normally closed contact 9-11 of the auxiliary switch DL1 and the second normally closed contact 5-7 of the auxiliary switch DL1 are switched to the open state, the first normally open contact 2-4 of the auxiliary switch DL1 and the second normally open contact 6-8 of the auxiliary switch DL1 are switched to the closed state, at this time, the resistor R1, the first normally closed contact 82-81 of the contactor KM2 and the contactor K The first normally closed contact 82-81 of M1, the armature winding ZH1-ZH2 of motor M1, the second normally closed contact 71-72 of contactor KM1, the second normally closed contact 71-72 of contactor KM2, the first normally open contact 2-4 of auxiliary switch DL1, the excitation winding D4-D3 of motor M1, and the second normally open contact 6-8 of auxiliary switch DL1 form a closed loop. At this time, the braking circuit is connected. After the auxiliary switch contacts are converted, the electromotive force in the armature winding during braking is opposite to the electromotive force in the armature winding when closing the switch, so that the motor is quickly braked and stopped, and a resistor is connected in series to limit the current.

9. The control brake circuit of the three-station mechanism as claimed in claim 6, characterized in that: The isolation and opening working mode is: after the isolation is closed, the first normally open contact 1-2 of the isolation closing position switch CK1 is closed. After the isolation and opening signal is issued, the current passes through the third normally closed contact 51-52 of the contactor KM2, the coil A1-A2 of the contactor KM1, the first normally closed contact 1-2 of the isolation closing position switch CK1, the first normally closed contact 1-2 of the isolation manual locking position switch CK5, the third normally closed contact 1-3 of the auxiliary switch DL2, the third normally closed contact 61-62 of the contactor KM3, the third normally closed contact 62-61 of the contactor KM4, and the interlocking Condition, reaches the second voltage N, at this time, after the contactor KM2 coil is energized, the fourth normally open contact 33-34 of the contactor KM2 is closed, the loop is self-maintained, the normally open contact of the contactor KM2 is closed, the normally closed contact is disconnected, and the current from the first input power supply L passes through the first normally open contact 23-24 of the contactor KM1, the armature winding ZH2-ZH1 of the motor M1, the second normally open contact 13-14 of the contactor KM1, the excitation winding D3-D4 of the motor M1, and the third normally open contact 44-43 of the contactor KM1, and reaches the second input power supply N, driving the motor to reverse, realizing the isolation and separation of the three-station mechanism. After the opening is in place, the first normally open contact 1-2 of the isolating opening travel switch CK1 is restored to the open state, the contactor KM1 coil is de-energized, the normally open contact of KM1 is restored to the open state, the normally closed contact is restored to the closed state, the first normally closed contact 9-11 of the auxiliary switch DL1 and the second normally closed contact 5-7 of the auxiliary switch DL1 are restored to the closed state, the first normally open contact 2-4 of the auxiliary switch DL1 and the second normally open contact 6-8 of the auxiliary switch DL1 are restored to the open state, at this time, the resistor R1, the first normally closed contact 82-81 of the contactor KM2, and the contactor K The first normally closed contact 82-81 of M1, the armature winding ZH1-ZH2 of motor M1, the second normally closed contact 71-72 of contactor KM1, the second normally closed contact 71-72 of contactor KM2, the first normally closed contact 9-11 of auxiliary switch DL1, the excitation winding D3-D4 of motor M1, and the second normally closed contact 5-7 of auxiliary switch DL1 form a closed loop. At this time, the braking circuit is connected. After the auxiliary switch contacts are converted, the electromotive force in the armature winding during braking is opposite to the electromotive force in the armature winding when closing the switch, so that the motor is quickly braked and stopped, and a resistor is connected in series to limit the current.

10. A detection method for a control brake circuit of a three-station mechanism based on the control brake circuit of the three-station mechanism according to claims 1-7, characterized in that: The method specifically includes: Taking the open state of the isolating switch control circuit as an example, two terminal connections are led out in the circuit, namely the first end 1 of terminal X1 and the first end 2 of terminal X1. Whether the brake circuit is normal can be determined by measuring the resistance at the first end 1 of terminal X1 and the first end 2 of terminal X1; the resistance of the armature winding ZH1-ZH2 of motor M1 is r1, the resistance of the excitation winding D3-D4 of motor M1 is r2, and the resistance of 1-2 of resistor R1 is r3. Then the theoretical resistance at the first end 1 of terminal X1 and the first end 2 of terminal X1 is r1×(r2+r3) / (r1+r2+r3). Whether the brake circuit is normal can be determined by comparing whether the measured value is consistent with the theoretical calculated value; the detection method of the closed state of the isolating switch control circuit and the open and closed state of the grounding switch control circuit is the same, and the resistance value is equal. Each state is detected once to determine whether the brake circuit of each state is normal.

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