Residual magnetism type operating mechanism control system and method

Abstract

The invention discloses a residual magnetism type operating mechanism control system and method, and relates to the field of electrical equipment, and the system is characterized in that a first power tube to a fourth power tube in a controller form a bridge circuit, the output end of the bridge circuit is connected with an opening and closing coil of a residual magnetism type operating mechanism, and an opening and closing capacitor is connected with the bridge circuit in parallel; the main control chip is used for controlling the second power tube and the third power tube to be switched on according to the first residual magnetism amount advance compensation value from opening to closing until the residual magnetism amount feedback value of the magnetic conductive rod is equal to the first residual magnetism amount advance compensation value; in the upward movement process of the movable alloy magnetic core, according to a first residual magnetism quantity given value, a displacement value of the movable alloy magnetic core and a current value of the opening and closing coil, a displacement-current double-closed-loop algorithm is used for controlling on-off of a second power tube and a third power tube; and when the movable alloy magnetic core moves to a switching-on position, the second power tube and the third power tube are controlled to be switched off, and the fifth power tube is controlled to be switched on. The accuracy of operation control of the operating mechanism is improved, and stable regulation and control of the operating mechanism are realized.

Description

A control system and method for a residual magnetism operating mechanism Technical Field

[0001] This application relates to the field of power equipment technology, and in particular to a control system and method for a residual magnetism operating mechanism. Background Technology

[0002] As a key piece of equipment in the power system, the performance of circuit breakers is crucial to the safe operation of the power grid, while the operating mechanism, as the core component of the circuit breaker, has extremely high requirements for operational reliability, operating speed, and control accuracy.

[0003] Currently, the mainstream operating mechanisms are divided into spring energy storage mechanisms and residual magnetism operating mechanisms. Residual magnetism operating mechanisms are gradually gaining attention due to their advantages in structural compactness, energy consumption control, and response speed. They achieve precise operation by adjusting the magnetic circuit path to control electromagnetic force.

[0004] The current control method for residual magnetism operating mechanisms is relatively simple, mainly employing direct switch control. When the operating mechanism needs to move from the open to the closed state, the switch controls the opening / closing coils to obtain a clockwise current; when the mechanism needs to move from the closed to the open state, the switch controls the opening / closing coils to obtain a counter-clockwise current. However, this direct-drive method lacks precision in operational control, making it difficult to stably regulate the residual magnetism and speed during operation, thus compromising the smoothness of the mechanism's operation. Summary of the Invention

[0005] The purpose of this application is to provide a control system and method for a residual magnetism-based operating mechanism, which improves the accuracy of mechanism operation control and achieves stable regulation of residual magnetism and movement speed during mechanism operation.

[0006] To achieve the above objectives, this application provides the following solution.

[0007] In a first aspect, this application provides a control system for a residual magnetism operating mechanism, comprising a residual magnetism operating mechanism and a controller; the residual magnetism operating mechanism includes at least a stationary alloy magnetic core, a moving alloy magnetic core, a magnetic rod, a magnetic induction coil, a closing / opening coil, and a linear displacement sensor; the controller includes a first power transistor, a second power transistor, a third power transistor, a fourth power transistor, a fifth power transistor, a current transformer, a closing / opening capacitor, a braking resistor, and a main control chip; the stationary alloy magnetic core is disposed above the moving alloy magnetic core; the closing / opening coil is disposed within the internal space between the stationary alloy magnetic core and the moving alloy magnetic core; The top of the opening and closing coil is fixed to the static alloy magnetic core; the magnetic rod passes sequentially through the magnetic induction coil, the static alloy magnetic core, and the opening and closing coil, and corresponds to the protruding platform inside the moving alloy magnetic core; the first power transistor, the second power transistor, the third power transistor, and the fourth power transistor form a bridge circuit; the output terminal of the bridge circuit is connected to the opening and closing coil; the current transformer is passed through by the connection between the bridge circuit and the opening and closing coil; the opening and closing capacitor is connected in parallel with the bridge circuit; the fifth power transistor is connected in series with the braking resistor and then connected in parallel with the opening and closing coil; the control chip The circuit is connected to the first power transistor, the second power transistor, the third power transistor, the fourth power transistor, the fifth power transistor, the current transformer, the linear displacement sensor, and the magnetic induction coil, respectively. The magnetic induction coil is used to sense the magnetic induction intensity during the opening and closing process of the magnetic rod. The linear displacement sensor is used to obtain the displacement value of the moving alloy magnetic core. The current transformer is used to obtain the current value of the opening and closing coil. The main control chip is used to execute the following steps when the residual magnetism operating mechanism changes from the opening state to the closing state: according to the preset first residual magnetism advance compensation value, control the second power transistor and the... The third power transistor is turned on until the residual magnetism feedback value of the magnetic rod equals the first residual magnetism advance compensation value; the residual magnetism feedback value is calculated based on the magnetic induction intensity; during the upward movement of the moving alloy magnetic core, the second power transistor and the third power transistor are controlled by a displacement-current dual closed-loop algorithm according to the preset first residual magnetism setpoint, the displacement value of the moving alloy magnetic core and the current value of the opening and closing coil; when the moving alloy magnetic core moves to the closing position, the second power transistor and the third power transistor are controlled to disconnect and the fifth power transistor is turned on, and the opening and closing coil is rapidly discharged through the braking resistor.

[0008] Secondly, this application also provides a control method for a residual magnetism operating mechanism, applied to the residual magnetism operating mechanism control system described in the first aspect. The control method includes the following steps when the residual magnetism operating mechanism changes from an open state to a closed state: the main control chip controls the second and third power transistors to conduct according to a preset first residual magnetism advance compensation value; the opening and closing capacitor discharges forward onto the opening and closing coil until the residual magnetism feedback value of the magnetic rod equals the first residual magnetism advance compensation value; the opening and closing coil forms a magnetic field and magnetizes the static alloy core, while the moving alloy core is magnetized through the magnetic rod. An attractive force is formed between the stationary alloy core and the moving alloy core. During the upward movement of the moving alloy core, the main control chip controls the switching of the second power transistor and the third power transistor using a displacement-current dual closed-loop algorithm based on a preset first residual magnetism value, the displacement value of the moving alloy core, and the current value of the opening and closing coil. When the moving alloy core moves to the closed position, the main control chip controls the second and third power transistors to disconnect and the fifth power transistor to turn on. The opening and closing coil discharges through the braking resistor, and the stationary alloy core and the moving alloy core no longer continue to be magnetized and accelerated.

[0009] Based on the specific embodiments provided in this application, the following technical effects are disclosed.

[0010] First, this application incorporates feedforward control, pre-adjusting the current of the opening and closing coils and injecting a pre-compensation value for residual magnetism. This accelerates the initial response of opening and closing, rapidly increasing the suction force when the operating mechanism starts closing, thus improving the timeliness and foresight of the mechanism control. Second, this application employs displacement-current dual closed-loop control. Through effective monitoring and closed-loop feedback adjustment of residual magnetism and displacement values, the current magnitude in the opening and closing coils can be dynamically corrected, ensuring that the residual magnetism and movement speed of the mechanism during operation remain within a preset reasonable range, significantly improving the control accuracy and operational stability of the operating mechanism. Furthermore, this application includes a braking circuit for the fifth power transistor. When the operating mechanism completes the opening and closing action or requires emergency braking, the fifth power transistor conducts, and the opening and closing coils discharge rapidly through the braking resistor. This avoids overshoot or component damage due to inertia, further ensuring the safety and reliability of the mechanism operation. Based on these features, this application improves the accuracy of mechanism operation control and achieves stable regulation of residual magnetism and movement speed during mechanism operation. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1 is a partial schematic diagram of a residual magnetism operating mechanism in one embodiment of this application.

[0013] Figure 2 is a cross-sectional schematic diagram of a residual magnetism operating mechanism in one embodiment of this application.

[0014] Figure 3 is a structural diagram of the controller in one embodiment of this application.

[0015] Figure 4 is a control flowchart of the residual magnetism operating mechanism from the open state to the closed state in another embodiment of this application.

[0016] Figure 5 is a control flowchart of the residual magnetism operating mechanism in another embodiment of this application when it is in the closed state.

[0017] Figure 6 is a control flowchart of the residual magnetism operating mechanism from the closed state to the open state in another embodiment of this application.

[0018] Figure 7 is an execution logic diagram of the dual closed loop in the embodiments of this application.

[0019] Reference numerals in the attached diagram: Static alloy magnetic core-1, first groove-11, moving alloy magnetic core-2, second groove-21, raised platform-22, second through hole-23, magnetic rod-3, third through hole-31, limiting ring-32, magnetic induction coil-4, opening spring-5, opening and closing coil-6, linear displacement sensor-7, controller-8, first power transistor-81, second power transistor-82, third power transistor-83, fourth power transistor-84, fifth power transistor-85, current transformer-86, opening and closing capacitor-87, braking resistor-88, and main control chip-89. Detailed Implementation

[0020] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] The operating mechanisms in existing circuit breakers lack precision in operational control, making it difficult to stably regulate residual magnetism and movement speed. While dual-loop control offers advantages in precise parameter adjustment, it has not been effectively applied to such mechanisms. It cannot coordinate the current in the opening and closing coils through feedforward and dual-loop control, hindering the stability and consistency of the mechanism during long-stroke operation and further limiting performance improvement. Therefore, technological breakthroughs are urgently needed to address these issues.

[0022] The purpose of this application is to provide a control system and method for a residual magnetism-based operating mechanism, which improves the accuracy of mechanism operation control and achieves stable regulation of residual magnetism and movement speed during mechanism operation.

[0023] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] In one exemplary embodiment, a remanent magnetization actuator control system is provided, which includes a remanent magnetization actuator and a controller.

[0025] As shown in Figures 1 and 2, the residual magnetism operating mechanism includes at least: a static alloy magnetic core 1, a moving alloy magnetic core 2, a magnetic guide rod 3, a magnetic induction coil 4, an insulating pull rod, a tripping spring 5, a tripping and closing coil 6, a linear displacement sensor 7, and a fixing block. The static alloy magnetic core 1 is positioned above the moving alloy magnetic core 2; the tripping and closing coil 6 is positioned within the internal space of the static alloy magnetic core 1 and the moving alloy magnetic core 2; the top of the tripping and closing coil 6 is fixed to the static alloy magnetic core 1; the magnetic guide rod 3 passes sequentially through the magnetic induction coil 4, the static alloy magnetic core 1, and the tripping and closing coil 6, and then corresponds to the protruding platform 22 within the moving alloy magnetic core 2.

[0026] Specifically, a first groove 11 is formed at the bottom center of the static alloy magnetic core 1; a first through hole is formed at the top center of the static alloy magnetic core 1; the first through hole and the first groove 11 are interconnected; a second groove 21 is formed at the top center of the moving alloy magnetic core 2; the second groove 21 is correspondingly arranged to the first groove 11; a raised platform 22 is provided in the second groove 21; a second through hole 23 is formed on the raised platform 22; the second through hole 23 penetrates the raised platform 22 and the bottom of the moving alloy magnetic core 2; the first groove 11, the second groove 21, the raised platform 22, the first through hole and the second through hole 23 are located on the same central axis; the magnetic guide rod 3 passes through the magnetic induction coil 4, the first through hole and the first groove 11 in sequence and corresponds to the raised platform 22; a third through hole 31 is formed on the magnetic guide rod 3; the third through hole 31 and the second through hole 23 are interconnected. The circuit breaker is connected to the arc-extinguishing chamber at one end of the insulating rod; the other end of the insulating rod passes through the third through hole 31 and the second through hole 23 in sequence and is connected to the fixing block; the two ends of the opening spring 5 are respectively sleeved on the magnetic rod 3 and the raised platform 22; the gap between the first groove 11 and the magnetic rod 3 and the gap between the second groove 23 and the raised platform 22 are used to place the opening and closing coil 6; one side of the opening and closing coil 6 is fixed in the first groove 11; the length of the magnetic rod 3 is greater than the height of the raised platform 22; a limit ring 32 is provided at the top of the magnetic rod 3; the inner ring of the limit ring 32 corresponds to the third through hole 31; the outer ring diameter of the limit ring 32 is greater than the diameter of the first through hole; the inner ring diameter of the limit ring 32 is equal to the diameter of the third through hole 31; the magnetic induction coil 4 is sleeved between the limit ring 32 and the static alloy magnetic core 1 through the magnetic rod 3. Among them, the magnetic induction coil 4 is used to sense the magnetic induction intensity during the opening and closing process of the magnetic rod 3; the linear displacement sensor 7 is used to obtain the displacement value of the moving alloy magnetic core 2.

[0027] In addition, the residual magnetism operating mechanism also includes a bracket and a buffer pad. The static alloy magnetic core 1 is fixed to the upper support plate of the bracket with screws, and the buffer pad is fixed to one side of the fixing block by an insulating tie rod. The fixing block is connected to the insulating tie rod by threads. The length of the magnetic rod 3 needs to be designed to match the voltage level and the mechanism stroke requirements. Based on the circuit breaker insulation level, arc-extinguishing chamber size, and typical mechanism stroke requirements, the residual magnetism operating mechanism can be widely applied to voltage levels such as 72.5kV, 110kV, and 220kV. For example, for a 110kV circuit breaker, its mechanism stroke is usually increased to 90-130mm, at which point the effective length of the magnetic rod 3 should be in the range of 180-260mm.

[0028] The aforementioned residual magnetism operating mechanism effectively solves the problems of insufficient magnetization and uneven magnetic field distribution during long-stroke closing, providing stable and reliable structural support for its high-voltage long-stroke stable operation. Therefore, it can be called a long-stroke residual magnetism operating mechanism. The main reason is that the aforementioned residual magnetism operating mechanism is equipped with a magnetic guide rod 3. The magnetic guide rod 3 passes through the first through hole and the first groove 11 of the stationary alloy magnetic core 1 and corresponds to the raised platform 22 in the second groove 21 of the moving alloy magnetic core 2. Since its length is determined according to the voltage level and the stroke of the mechanism, and the length of the magnetic guide rod 3 is greater than that of the raised platform 22, its length is determined according to the voltage level and the stroke of the mechanism. The height of platform 22 allows the magnetic rod 3 to be easily lifted and lowered from the first through hole during the opening and closing process. When the moving alloy core 2 is far from the opening and closing coil 6, it is difficult to be directly magnetized. Since the opening and closing coil 6 is fixed on the side of the magnetic rod and the length of the magnetic rod 3 is sufficient, the magnetomotive force generated by the opening and closing coil 6 at the stationary alloy core 1 can be coupled to the moving alloy core side through the magnetic rod 3, thereby forming an effective attraction between the stationary alloy core 1 and the moving alloy core 2. This solves the problem of insufficient magnetization and uneven magnetic field distribution in the long-stroke closing of the residual magnetism operating mechanism.

[0029] As shown in Figure 3, the controller 8 includes a first power transistor 81, a second power transistor 82, a third power transistor 83, a fourth power transistor 84, a fifth power transistor 85, a current transformer 86, a switching capacitor 87, a braking resistor 88, and a main control chip 89.

[0030] Specifically, the first power transistor 81, the second power transistor 82, the third power transistor 83, and the fourth power transistor 84 form a bridge circuit; the output terminal of the bridge circuit is connected to the opening and closing coil 6; the current transformer 86 is passed through by the connection between the bridge circuit and the opening and closing coil 6; the opening and closing capacitor 87 is connected in parallel with the bridge circuit; the fifth power transistor 85 and the braking resistor 88 are connected in series and then connected in parallel with the opening and closing coil 6; the control chip 89 is connected to the first power transistor 81, the second power transistor 82, the third power transistor 83, the fourth power transistor 84, the fifth power transistor 85, the current transformer 86, the linear displacement sensor 7, and the magnetic induction coil 4, respectively.

[0031] The current transformer 86 is used to obtain the current value of the opening and closing coil 6. The main control chip 89 is used to execute the following steps when the residual magnetism operating mechanism changes from the opening state to the closing state: according to the preset first residual magnetism advance compensation value, the second power transistor 82 and the third power transistor 83 are controlled to conduct until the residual magnetism feedback value of the magnetic rod 3 is equal to the first residual magnetism advance compensation value; the residual magnetism feedback value is calculated based on the magnetic induction intensity; during the upward movement of the moving alloy magnetic core 2, according to the preset first residual magnetism setpoint, the displacement value of the moving alloy magnetic core 2 and the current value of the opening and closing coil 6, the displacement-current double closed-loop algorithm is used to control the on and off of the second power transistor 82 and the third power transistor 83; when the moving alloy magnetic core 2 moves to the closing position, the second power transistor 82 and the third power transistor 83 are controlled to disconnect and the fifth power transistor 85 is turned on, and the opening and closing coil 6 is rapidly discharged through the braking resistor 88.

[0032] In a preferred embodiment, one end of the switching capacitor 87 is connected to one end of the first power transistor 81 and one end of the second power transistor 82, respectively; the other end of the switching capacitor 87 is connected to one end of the third power transistor 83 and one end of the fourth power transistor 84, respectively; the other end of the first power transistor 81 is connected to the other end of the third power transistor 83 and one end of the switching coil 6, respectively; the other end of the second power transistor 82 is connected to the other end of the fourth power transistor 84 and the other end of the switching coil 6, respectively; the current transformer 86 is sleeved on the line connecting the other end of the first power transistor 81 and the switching coil 6; one end of the fifth power transistor 85 is connected to one end of the switching coil 6; the other end of the fifth power transistor 85 is connected to one end of the braking resistor 88; and the other end of the braking resistor 88 is connected to the other end of the switching coil 6.

[0033] In addition, the main control chip 89 contains a displacement regulator, a remanence regulator, a current regulator, a PWM generator, and a feedforward controller. These modules are virtual functional modules, mainly implemented through software programming languages. The displacement regulator and the remanence regulator execute a slow PID algorithm, the current regulator executes a fast PID algorithm, and the feedforward controller executes a proportional P algorithm. The logic code of the above modules and the main logic code of the remanence-type operating mechanism control method are stored together in the main control chip. Specifically, the current regulator is connected to the displacement regulator and the remanence regulator (logic); the PWM generator is connected to the current regulator and the feedforward controller (logic); and the first power transistor 81, the second power transistor 82, the third power transistor 83, the fourth power transistor 84, and the fifth power transistor 85 are connected to the PWM generator.

[0034] In another exemplary embodiment, a residual magnetism operating mechanism control method is provided, applied to the above-mentioned residual magnetism operating mechanism control system, and the residual magnetism operating mechanism control method is as follows.

[0035] As shown in Figure 4, when the above-mentioned residual magnetism operating mechanism changes from the open state to the closed state (the controller needs to be powered on, and the opening and closing capacitors have completed energy storage), the following steps are executed: Step S11: The main control chip controls the second power transistor and the third power transistor to conduct according to the preset first residual magnetism advance compensation value, and the opening and closing capacitors discharge positively to the opening and closing coils until the residual magnetism feedback value of the magnetic rod is equal to the first residual magnetism advance compensation value.

[0036] The main control chip first reads the preset first residual magnetism advance compensation value and inputs it into the feedforward controller to execute the proportional P algorithm. Then, the PWM generator generates control signals for the second and third power transistors based on the output of the feedforward controller, changing the conduction states of the second and third power transistors. Simultaneously, the opening and closing coils generate a magnetic field, magnetizing the stationary alloy core. Because the moving alloy core in the open state is far from the opening and closing coils, it cannot be directly magnetized. However, due to the presence of the magnetic guide rod, the moving alloy core can be magnetized through the guide rod, creating an attractive force between the stationary and moving alloy cores. As the attractive force between the stationary and moving alloy cores increases, when the attractive force on the moving alloy core exceeds the elastic force of the compressed opening spring, the moving alloy core begins to move upwards.

[0037] Step S12: During the upward movement of the moving alloy core, the main control chip controls the switching on and off of the second and third power transistors using a displacement-current dual closed-loop algorithm based on the preset first residual magnetism value, the displacement value of the moving alloy core, and the current value of the opening and closing coils.

[0038] The main control chip first reads the preset first residual magnetism setpoint and the displacement value of the moving alloy core. Then, it calculates the difference between the first residual magnetism setpoint and the displacement value of the moving alloy core and inputs it to the displacement regulator to execute a slow PID algorithm. The output result of the displacement regulator is subtracted from the current value of the opening and closing coil and input to the current regulator to execute a fast PID algorithm. The PWM generator changes the control signals of the second and third power transistors according to the output result of the current regulator, thereby achieving effective control of the on / off state of the second and third power transistors. As the magnitude of the current in the opening and closing coil continuously changes, the residual magnetism between the stationary and moving alloy cores is effectively controlled, which in turn effectively controls the attraction force and upward movement speed between the stationary and moving alloy cores.

[0039] Step S13: When the moving alloy magnetic core moves to the closed position, the main control chip controls the second and third power transistors to disconnect and the fifth power transistor to turn on.

[0040] In the main control chip, after the PWM generator controls the second and third power transistors to disconnect and the fifth power transistor to turn on, the opening and closing coils discharge rapidly through the braking resistor. The stationary and moving alloy cores cease magnetization, thereby reducing the contact collision speed between them. When the moving alloy core decelerates to zero, the attraction between the stationary and moving alloy cores provides an upward holding force for the residual magnetism operating mechanism, keeping it in the closed position. The closing process is then complete.

[0041] As shown in Figure 5, when the above-mentioned residual magnetism operating mechanism is in the closed state, the following steps are executed: Step S21: The main control chip obtains the magnetic induction intensity of the magnetic rod at set intervals and calculates the current residual magnetism feedback value based on the current magnetic induction intensity of the magnetic rod.

[0042] After the main control chip reads the current magnetic flux density of the magnetic rod, it uses the formula... ( Calculate the current residual magnetism feedback value of the magnetic rod (where B is the magnetic flux density and S is the cross-sectional area of ​​the magnetic rod).

[0043] Step S22: When the difference between the residual magnetism feedback value when the magnetic rod is closed and the current residual magnetism feedback value of the magnetic rod is greater than the set threshold, the main control chip uses the residual magnetism-current dual closed-loop algorithm to control the on / off state of the second and third power transistors according to the first residual magnetism setpoint, the current residual magnetism feedback value of the magnetic rod and the current value of the opening and closing coils, thereby changing the current magnitude in the opening and closing coils until the current residual magnetism feedback value of the magnetic rod is the same as the first residual magnetism setpoint.

[0044] In this embodiment, a threshold of 10% is set. When the difference between the residual magnetism feedback value when the magnetic rod is closed and the current residual magnetism feedback value of the magnetic rod is greater than 10%, the main control chip first calculates the difference between the first residual magnetism setpoint and the current residual magnetism feedback value and inputs it to the residual magnetism regulator to execute a slow PID algorithm. The output result of the residual magnetism regulator is then subtracted from the current value of the opening and closing coils and input to the current regulator to execute a fast PID algorithm. The PWM generator changes the control signals of the second and third power transistors according to the output result of the current regulator, thereby achieving effective control of the on / off state of the second and third power transistors. Because the current in the opening and closing coils is effectively controlled, the residual magnetism between the static alloy core and the moving alloy core will remain unchanged from the setpoint, thus preventing the tripping fault caused by interference.

[0045] As shown in Figure 6, when the above-mentioned residual magnetism operating mechanism changes from the closed state to the open state (the controller needs to be powered on, and the opening and closing capacitor has completed energy storage), the following steps are executed: Step S31: The main control chip controls the first power transistor and the fourth power transistor to conduct according to the preset second residual magnetism advance compensation value, and the opening and closing capacitor discharges in reverse to the opening and closing coil.

[0046] The main control chip first reads the preset second residual magnetism advance compensation value and inputs it into the feedforward controller to execute the proportional P algorithm. Then, the PWM generator generates control signals for the first and fourth power transistors based on the output of the feedforward controller, changing the conduction states of the first and fourth power transistors. At the same time, the opening and closing coils generate a reverse magnetic field, demagnetizing the stationary and moving alloy cores. As the attraction between the stationary and moving alloy cores decreases, when the attraction of the stationary alloy core to the moving alloy core becomes less than the downward force of the compressed opening spring, the moving alloy core begins to move downward.

[0047] Step S32: During the downward movement of the moving alloy core, the main control chip controls the switching on and off of the first power transistor and the fourth power transistor using a displacement-current dual closed-loop algorithm based on the preset second residual magnetism value, the displacement value of the moving alloy core, and the current value of the opening and closing coil, thereby changing the magnitude of the current in the opening and closing coil.

[0048] The main control chip first reads the preset second residual magnetism setpoint and the displacement value of the moving alloy core. Then, it calculates the difference between the second residual magnetism setpoint and the displacement value of the moving alloy core and inputs it to the displacement regulator to execute a slow PID algorithm. The output result of the displacement regulator is subtracted from the current value of the opening and closing coils and input to the current regulator to execute a fast PID algorithm. The PWM generator changes the control signals of the first and fourth power transistors according to the output result of the current regulator, thereby achieving effective control of the on / off state of the first and fourth power transistors. As the magnitude of the current in the opening and closing coils continuously changes, the residual magnetism between the stationary and moving alloy cores is effectively controlled, which in turn effectively controls the demagnetization rate and downward movement speed between the stationary and moving alloy cores.

[0049] Step S33: When the moving alloy magnetic core moves to the open position, the main control chip controls the first power transistor and the fourth power transistor to disconnect and the fifth power transistor to turn on.

[0050] In the main control chip, after the PWM generator controls the first and fourth power transistors to disconnect and the fifth power transistor to turn on, the opening and closing coils discharge rapidly through the braking resistor. This prevents further demagnetization of the stationary and moving alloy cores, thus reducing their contact and collision speed. When the moving alloy core decelerates to zero, the attraction between the stationary and moving alloy cores is zero. The opening spring then provides a downward holding force to the residual magnetism operating mechanism, keeping it in the open position, thus completing the opening process.

[0051] As shown in Figure 7, this embodiment focuses on the design of a feedforward controller, an outer-loop negative feedback (displacement / residual magnetism loop), and an inner-loop negative feedback (current loop). The feedforward controller is primarily used for power transistor control during the early stage of the residual magnetism operating mechanism's movement. A pre-set residual magnetism advance compensation value is input to the feedforward controller, and the output of the feedforward controller is fed to the PWM regulator. The PWM regulator controls the on / off state of the corresponding power transistor to achieve advanced adjustment of the residual magnetism operating mechanism, injecting residual magnetism adjustment amount in advance, accelerating the initial response of opening and closing, and causing the attraction force to increase rapidly when the residual magnetism operating mechanism starts closing, and the demagnetization speed to be faster when opening. The outer-loop negative feedback includes displacement closed-loop control and residual magnetism closed-loop control. The outer-loop negative feedback executed during the opening and closing process is displacement closed-loop control, which mainly provides the difference between the residual magnetism setpoint and the displacement value of the moving alloy magnetic core to the displacement regulator. The outer-loop negative feedback executed during the holding phase after closing is residual magnetism closed-loop control, which mainly provides the difference between the residual magnetism setpoint and the residual magnetism feedback value of the magnetic rod to the residual magnetism regulator. The inner loop negative feedback is mainly current closed-loop control, that is, the difference between the output of the displacement / residual magnetism regulator and the current value of the opening and closing coil is given to the current regulator, the output of the current regulator is given to the PWM regulator, and the PWM regulator controls the on and off of the corresponding power transistor to achieve effective control of the motion process of the residual magnetism operating mechanism, making its motion smoother.

[0052] Furthermore, in this embodiment, both the residual magnetism setpoint and the residual magnetism advance compensation value are vector values. The residual magnetism setpoint is determined based on the magnitude of the short-circuit current that the circuit breaker can withstand. The larger the withstand current, the larger the residual magnetism setpoint. For example, if the withstand current is 25kA, the attraction between the static alloy core and the moving alloy core needs to be greater than 480N. Therefore, the residual magnetism setpoint should be 1.340 × 10⁻⁶. -3 Wb. The settings for the residual magnetism setpoint and residual magnetism advance compensation value differ depending on the mechanism's state: During the opening to closing process, both the residual magnetism setpoint and the residual magnetism advance compensation value are positive. The residual magnetism setpoint is determined by the magnitude of the short-circuit current it can withstand. The residual magnetism advance compensation value is preferably set to 50% of the residual magnetism setpoint. If a faster closing speed is desired for the residual magnetism-type operating mechanism, the residual magnetism advance compensation value can be further increased. However, if this value becomes too large, the adjustment space for the dual closed-loop system will decrease, and the difficulty of fine-tuning will increase. During the closing and holding process, the residual magnetism setpoint remains the same as that during the opening to closing process. During the closing to opening process, both the residual magnetism setpoint and the residual magnetism advance compensation value are negative. The residual magnetism setpoint is determined by the magnitude of the short-circuit current it can withstand. The residual magnetism advance compensation value is preferably set to 50% of the residual magnetism setpoint. If a faster opening speed is desired for the residual magnetism-type operating mechanism, the residual magnetism advance compensation value can be further increased. However, if this value becomes too large, the adjustment space for the dual closed-loop system will decrease, and the difficulty of fine-tuning will increase.

[0053] In one preferred embodiment, the first and second residual magnetism values ​​can be equal in magnitude and opposite in direction. Alternatively, the first residual magnetism value can be greater than or equal to the second residual magnetism value. The advance compensation value of the first residual magnetism value is 50% of the first residual magnetism value, and the advance compensation value of the second residual magnetism value is set to 50% of the second residual magnetism value.

[0054] In summary, this application has the following main advantages.

[0055] (1) This application incorporates feedforward control, which can combine the preset parameters of the operating mechanism to make predictive adjustments to the current of the opening and closing coils in advance, inject residual magnetism adjustment amount in advance, accelerate the initial response of opening and closing, so that the attraction force increases rapidly when the operating mechanism starts closing and the demagnetization speed is faster when opening, thus improving the timeliness and foresight of the control.

[0056] (2) This application adopts displacement-current dual closed-loop control. By real-time monitoring and closed-loop feedback adjustment of residual magnetism and displacement of moving alloy core, the opening and closing coil current can be dynamically corrected to ensure that the residual magnetism and movement speed of the operating mechanism are always within the preset reasonable range during long-stroke operation, which greatly improves its control accuracy and operation stability.

[0057] (3) When the operating mechanism is closed and held, this application also adopts a dual closed-loop control of residual magnetism and current. By real-time monitoring and closed-loop feedback adjustment of the feedback values ​​of residual magnetism and residual magnetism of the magnetic rod, the current of the opening and closing coils can be dynamically supplied, ensuring that the difference between the feedback value of residual magnetism and the given value of residual magnetism is always less than 10% during the long-term closing and holding process of the operating mechanism, thereby avoiding the phenomenon of sudden tripping caused by external interference.

[0058] (4) This application sets up a braking circuit for the fifth power tube. When the operating mechanism completes the opening and closing action or needs emergency braking, the fifth power tube can quickly introduce the braking discharge circuit to achieve precise braking of the operating mechanism, avoid overshoot of action or damage to components due to inertia, and further ensure the safety and reliability of the mechanism operation.

[0059] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0060] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A control system for a residual magnetism-type operating mechanism, characterized in that, The residual magnetism operating mechanism control system includes a residual magnetism operating mechanism and a controller. The residual magnetism operating mechanism includes at least a static alloy magnetic core, a moving alloy magnetic core, a magnetic guide rod, a magnetic induction coil, a switching coil, and a linear displacement sensor. The controller includes a first power transistor, a second power transistor, a third power transistor, a fourth power transistor, a fifth power transistor, a current transformer, a switching capacitor, a braking resistor, and a main control chip. The static alloy magnetic core is disposed above the moving alloy magnetic core. The switching coil is disposed within the internal space of the static alloy magnetic core and the moving alloy magnetic core. The top of the switching coil is fixed to the static alloy magnetic core. The magnetic guide rod passes sequentially through the magnetic induction coil, the static alloy magnetic core, and the switching coil, and corresponds to a protruding platform within the moving alloy magnetic core. The first power transistor, the second power transistor, the third power transistor, and the fourth power transistor form a bridge circuit. The output terminal of the bridge circuit is connected to the switching coil. The current transformer is passed through by the connection between the bridge circuit and the switching coil. The switching capacitor is connected in parallel with the bridge circuit. The fifth power transistor is connected in series with the braking resistor and then in parallel with the opening and closing coil; the control chip is connected to the first power transistor, the second power transistor, the third power transistor, the fourth power transistor, the fifth power transistor, the current transformer, the linear displacement sensor, and the magnetic induction coil; the magnetic induction coil is used to sense the magnetic induction intensity during the opening and closing process of the magnetic rod; the linear displacement sensor is used to obtain the displacement value of the moving alloy magnetic core; the current transformer is used to obtain the current value of the opening and closing coil; the main control chip is used to execute the following steps when the residual magnetism operating mechanism changes from the opening state to the closing state: according to the preset first residual magnetism advance compensation value, control the second power transistor and the third power transistor to conduct until the residual magnetism feedback value of the magnetic rod is equal to the first residual magnetism advance compensation value; The residual magnetism feedback value is calculated based on the magnetic induction intensity. During the upward movement of the moving alloy core, the second power transistor and the third power transistor are controlled by a displacement-current dual closed-loop algorithm based on the preset first residual magnetism value, the displacement value of the moving alloy core, and the current value of the opening and closing coil. When the moving alloy core moves to the closing position, the second power transistor and the third power transistor are controlled to disconnect, the fifth power transistor is controlled to conduct, and the opening and closing coil is rapidly discharged through the braking resistor.

2. The control system for the residual magnetism operating mechanism according to claim 1, characterized in that, One end of the switching capacitor is connected to one end of the first power transistor and one end of the second power transistor, respectively; the other end of the switching capacitor is connected to one end of the third power transistor and one end of the fourth power transistor, respectively; the other end of the first power transistor is connected to the other end of the third power transistor and one end of the switching coil, respectively; the other end of the second power transistor is connected to the other end of the fourth power transistor and the other end of the switching coil, respectively; the current transformer is sleeved on the line connecting the other end of the first power transistor and the switching coil; one end of the fifth power transistor is connected to one end of the switching coil; the other end of the fifth power transistor is connected to one end of the braking resistor; the other end of the braking resistor is connected to the other end of the switching coil.

3. The control system for the residual magnetism operating mechanism according to claim 1, characterized in that, The main control chip includes a displacement regulator, a remanence regulator, a current regulator, a PWM generator, and a feedforward controller. The current regulator is connected to both the displacement regulator and the remanence regulator. The PWM generator is connected to both the current regulator and the feedforward controller. The first power transistor, the second power transistor, the third power transistor, the fourth power transistor, and the fifth power transistor are connected to the PWM generator.

4. The control system for the residual magnetism operating mechanism according to claim 1, characterized in that, The residual magnetism operating mechanism further includes: a tripping spring, an insulating pull rod, and a fixing block; the two ends of the tripping spring are respectively sleeved on the magnetic guide rod and the raised platform; one end of the insulating pull rod is connected to the arc-extinguishing chamber of the circuit breaker; a first groove is formed at the bottom center of the static alloy magnetic core; a first through hole is formed at the top center of the static alloy magnetic core; the magnetic guide rod passes through the magnetic induction coil, the first through hole, and the first groove in sequence and corresponds to the raised platform; a second through hole is formed on the raised platform; the second through hole penetrates the raised platform and the bottom of the moving alloy magnetic core; a third through hole is formed on the magnetic guide rod; the other end of the insulating pull rod passes through the third through hole and the second through hole in sequence and is connected to the fixing block.

5. A control method for a residual magnetism-type operating mechanism, characterized in that, The residual magnetism operating mechanism control system according to any one of claims 1-4, wherein the residual magnetism operating mechanism control method includes: when the residual magnetism operating mechanism changes from an open state to a closed state, the following steps are executed: the main control chip controls the second power transistor and the third power transistor to conduct according to a preset first residual magnetism advance compensation value; the opening and closing capacitor discharges forward to the opening and closing coil until the residual magnetism feedback value of the magnetic rod is equal to the first residual magnetism advance compensation value; the opening and closing coil forms a magnetic field and magnetizes the stationary alloy core, the moving alloy core is magnetized through the magnetic rod, and the stationary alloy core and the... An attractive force is formed between the moving alloy magnetic cores. During the upward movement of the moving alloy magnetic cores, the main control chip controls the switching of the second power transistor and the third power transistor using a displacement-current dual closed-loop algorithm based on a preset first residual magnetism value, the displacement value of the moving alloy magnetic core, and the current value of the opening and closing coil. When the moving alloy magnetic core moves to the closed position, the main control chip controls the second power transistor and the third power transistor to disconnect and the fifth power transistor to turn on. The opening and closing coil discharges through the braking resistor, and the stationary alloy magnetic core and the moving alloy magnetic core no longer continue to be magnetized.

6. The control method for the residual magnetism operating mechanism according to claim 5, characterized in that, The control method for the residual magnetism operating mechanism further includes: when the residual magnetism operating mechanism is in the closed state, the following steps are performed: the main control chip acquires the magnetic induction intensity of the magnetic rod at set intervals, and calculates the current residual magnetism feedback value based on the current magnetic induction intensity of the magnetic rod; when the difference between the residual magnetism feedback value when the magnetic rod is closed and the current residual magnetism feedback value of the magnetic rod is greater than a set threshold, the main control chip controls the on / off state of the second power transistor and the third power transistor using a residual magnetism-current dual closed-loop algorithm based on the first residual magnetism given value, the current residual magnetism feedback value of the magnetic rod, and the current value of the opening and closing coil, thereby changing the current magnitude in the opening and closing coil until the current residual magnetism feedback value of the magnetic rod is the same as the first residual magnetism given value.

7. The control method for the residual magnetism operating mechanism according to claim 5, characterized in that, The control method for the residual magnetism operating mechanism further includes the following steps when the residual magnetism operating mechanism changes from the closed state to the open state: the main control chip controls the first power transistor and the fourth power transistor to conduct according to a preset second residual magnetism advance compensation value, and the opening and closing capacitor discharges in the reverse direction to the opening and closing coil; the opening and closing coil forms a reverse magnetic field, and the stationary alloy core and the moving alloy core are demagnetized; during the downward movement of the moving alloy core, the main control chip controls the on / off state of the first power transistor and the fourth power transistor according to a preset second residual magnetism setpoint, the displacement value of the moving alloy core and the current value of the opening and closing coil using a displacement-current dual closed-loop algorithm, thereby changing the current magnitude in the opening and closing coil; when the moving alloy core moves to the open position, the main control chip controls the first power transistor and the fourth power transistor to disconnect and the fifth power transistor to conduct; the opening and closing coil discharges through the braking resistor, and the stationary alloy core and the moving alloy core no longer continue to demagnetize.

8. The control method for the residual magnetism operating mechanism according to claim 5 or 7, characterized in that, The main control chip is equipped with a displacement regulator, a current regulator, and a PWM generator; the displacement-current dual closed-loop algorithm specifically involves: calculating the difference between the given value of the residual magnetism and the displacement value of the moving alloy magnetic core, and inputting it into the displacement regulator; calculating the difference between the output result of the displacement regulator and the current value of the opening and closing coil, and inputting it into the current regulator; The PWM generator controls the on / off state of the corresponding power transistors based on the output of the current regulator; during the upward movement of the moving alloy core, the PWM generator controls the on / off state of the second and third power transistors; during the downward movement of the moving alloy core, the PWM generator controls the on / off state of the first and fourth power transistors.

9. The control method for the residual magnetism operating mechanism according to claim 6, characterized in that, The main control chip is equipped with a residual magnetism regulator, a current regulator, and a PWM generator; the residual magnetism-current dual closed-loop algorithm specifically involves: calculating the difference between the first residual magnetism setpoint and the residual magnetism feedback value of the magnetic rod, and inputting it into the residual magnetism regulator; calculating the difference between the output result of the residual magnetism regulator and the current value of the opening and closing coil, and inputting it into the current regulator; The PWM generator controls the switching on and off of the second power transistor and the third power transistor based on the output of the current regulator.

10. The control method for the residual magnetism operating mechanism according to claim 7, characterized in that, The first residual magnetism setpoint is greater than or equal to the second residual magnetism setpoint; the first residual magnetism advance compensation value is less than the first residual magnetism setpoint; the second residual magnetism advance compensation value is less than the second residual magnetism setpoint.

Images