Magnetic latching relay action detection circuit in voltage regulator and connection structure

Abstract

The utility model relates to the technical field of power equipment structure discloses a magnetic latching relay action detection circuit and connecting structure in voltage regulator, aims at solving the magnetic latching relay action time detection inaccuracy, the anti -interference ability is insufficient and the inrush current and arc problem in the prior art. Detection circuit and connecting structure are arranged in the inside of voltage regulator casing, including PCB control panel and magnetic latching relay, and the singlechip, drive circuit, auxiliary contact module and action detection circuit are integrated on the PCB control panel. Action detection circuit realizes signal electrical isolation through photoelectric coupler isolator, and utilizes RC filter circuit to suppress high -frequency noise, ensures signal sampling accurate. Auxiliary contact module is through contact switch subassembly and main contact mechanical linkage. The utility model can accurately detect the action time of magnetic latching relay, effectively suppresses the power grid interference, solves the inrush current and arc problem, and significantly improves the operation reliability and security of voltage regulator under the complex power grid environment.

Description

Technical Field

[0001] This utility model relates to the field of power equipment structure technology, specifically to a magnetic latching relay action detection circuit and connection structure in a voltage regulator. Background Technology

[0002] A voltage regulator for low-voltage distribution lines is an important device installed at the end of low-voltage distribution lines. It is primarily used to address voltage quality issues caused by excessively long transmission lines or distributed photovoltaic (PV) grid connections. These issues include low voltage at the line end and excessively high voltage due to reverse power transmission from distributed sources, collectively referred to as bidirectional voltage limit exceedance problems. The regulator uses an autotransformer as its core regulating unit and employs a magnetic latching relay to control the number of turns in the transformer's coil connected to the grid to achieve voltage regulation.

[0003] However, in actual operation, the operation of magnetic latching relays faces the following technical challenges:

[0004] 1. Inrush current and arcing issues: Under load, inrush current and arcing can occur due to the potential difference across the coil when the relay switches. Inrush current can impact the power grid and affect the stable operation of equipment; while arcing can cause localized high-temperature melting of the relay contacts, leading to problems such as contact adhesion and difficulty in separation. In severe cases, it can even damage equipment and threaten power grid safety.

[0005] 2. Inaccurate Action Time Detection: The action time of a magnetic latching relay is a critical parameter for the normal operation of a voltage regulator, especially when using synchronous switching technology, where the accuracy of the action time directly determines the voltage regulation effect. However, the detection circuit in existing technology is susceptible to power grid interference, leading to inaccurate signal sampling and thus making it impossible to reliably determine the actual action time of the relay.

[0006] 3. Insufficient anti-interference capability: Traditional detection circuits lack effective anti-interference measures. In complex power grid environments, such as when there is high-frequency noise or strong electromagnetic interference, misjudgment or missed detection is likely to occur, which further reduces the reliability and safety of the voltage regulator.

[0007] To address these issues, existing voltage regulators typically employ transition current-limiting resistor technology or synchronous switching technology to mitigate the effects of inrush current and arcing. However, these technologies rely heavily on accurate detection of relay operating time, and existing detection schemes still have significant shortcomings in terms of anti-interference capability and detection accuracy. Utility Model Content

[0008] To address the aforementioned issues, this invention proposes a feedback detection circuit and connection structure that can effectively suppress interference and accurately detect the operating time of a magnetic latching relay, thereby improving the operational reliability of the voltage regulator in complex power grid environments and resolving safety hazards and technical bottlenecks caused by inrush current, arcing, and detection errors.

[0009] The technical solution adopted in this utility model is as follows:

[0010] The magnetic latching relay action detection circuit and connection structure in the voltage regulator are arranged inside the voltage regulator housing. The action detection circuit and connection structure are electrically connected to the voltage regulator's compensating autotransformer and heat dissipation device, together forming a complete voltage regulator system.

[0011] The motion detection circuit and connection structure include a PCB control board and a magnetic latching relay. The PCB control board is equipped with a microcontroller, a drive circuit, an auxiliary contact module, and a motion detection circuit.

[0012] The microcontroller is electrically connected to the drive circuit, auxiliary contact module, and motion detection circuit via a PCB control board. The drive circuit is electrically connected to the magnetic latching relay via wires, and the auxiliary contact module and motion detection circuit are electrically connected to the magnetic latching relay via contact switch assemblies.

[0013] Furthermore, the motion detection circuit includes an optocoupler isolator, voltage divider resistors R1 and R2, and an RC filter circuit;

[0014] The input side of the optocoupler is connected to the main contact K1 of the magnetic latching relay via a wire, and its output side is connected to the microcontroller via a wire. The output side of the optocoupler has an independent grounding terminal. Voltage divider resistors R1 and R2 are connected in series in the input circuit of the optocoupler. The RC filter circuit includes a filter capacitor C1 and a resistor R3. The resistor R3 is connected in series between the output terminal of the optocoupler and the microcontroller, and the filter capacitor C1 is connected in parallel between the output terminal of the optocoupler and ground.

[0015] Furthermore, the contact switch assembly includes a stainless steel connecting rod, and the input side of the auxiliary contact module is connected to the auxiliary contact K2 via a wire; the main contact K1 of the magnetic latching relay is mechanically linked to the auxiliary contact module via the stainless steel connecting rod, and the stainless steel connecting rod transmits the action of the main contact K1 to the auxiliary contact K2.

[0016] Furthermore, the auxiliary contact K2 is in elastic contact with the stainless steel connecting rod via a spring sheet.

[0017] The magnetic latching relay action detection circuit and connection structure in the voltage regulator provided by this utility model have the following beneficial effects:

[0018] 1. Accurate detection of magnetic latching relay action time: Through the cooperation of auxiliary contact module and optocoupler isolator, the action status of magnetic latching relay is fed back in real time. Combined with the timing difference analysis of main contact and auxiliary contact signals by microcontroller, the actual action time of relay can be accurately determined, which solves the problem of inaccurate signal sampling caused by power grid interference in traditional detection circuits.

[0019] 2. Significantly improved anti-interference capability: The action detection circuit uses an optocoupler isolator to achieve electrical isolation between high-voltage and low-voltage circuits, effectively avoiding interference from power grid noise on the detection signal; at the same time, the RC filter circuit further suppresses high-frequency noise, ensuring signal purity and significantly improving the reliability of the detection circuit in complex power grid environments.

[0020] 3. Solving inrush and arcing problems: By optimizing the mechanical linkage design, namely the elastic contact between the stainless steel connecting rod and the spring plate, the synchronous action stability of the main contact and the auxiliary contact is ensured, reducing the contact problems caused by mechanical vibration or wear, thereby reducing the probability of inrush and arcing phenomena and extending the service life of the relay contacts.

[0021] 4. Simple and efficient circuit design: The action detection circuit has a simple structure, mainly composed of optocoupler isolators, voltage divider resistors and RC filter circuits. It is easy to integrate into existing voltage regulator systems, and is low in cost and easy to maintain, making it suitable for application needs in different environments.

[0022] 5. Improve the reliability and safety of voltage regulator operation: Through precise action time detection and anti-interference design, equipment failure or power grid safety hazards caused by detection errors are avoided, the overall performance of the voltage regulator under complex operating conditions is improved, and the stable operation of low-voltage lines in the distribution network is guaranteed. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this utility model. For those skilled in the art, other drawings can be obtained based on these drawings.

[0024] Figure 1 This is a schematic diagram of the overall structure of the magnetic latching relay action detection circuit and connection structure in the voltage regulator of this utility model;

[0025] Figure 2 This is a schematic diagram showing the connection relationship of the motion detection circuit of this utility model;

[0026] In the diagram: 1. Magnetic latching relay; 2. Stainless steel connecting rod; 3. Spring plate. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model.

[0028] Therefore, the following detailed description of the embodiments of this utility model is not intended to limit the scope of the claimed utility model, but merely illustrates some embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model. It should be noted that, in the absence of conflict, the embodiments and features and technical solutions in the embodiments of this utility model can be combined with each other. It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0029] To address the issues of inaccurate timing detection, insufficient anti-interference capability, inrush current, and arcing problems in existing magnetic latching relays, this embodiment provides a magnetic latching relay action detection circuit and connection structure for a voltage regulator. This circuit and connection structure significantly improves the operational reliability of the voltage regulator in complex power grid environments by optimizing mechanical linkage, electrical isolation, and signal processing. The magnetic latching relay action detection circuit and connection structure are housed inside the voltage regulator housing and are electrically connected to the regulator's autotransformer and heat dissipation device, together forming a complete voltage regulator system.

[0030] like Figure 1 As shown, the magnetic latching relay action detection circuit and connection structure in this voltage regulator includes a PCB control board and a magnetic latching relay 1. The PCB control board integrates the core control circuit to realize signal processing, drive control and feedback detection functions; it is equipped with a microcontroller, drive circuit, auxiliary contact module and action detection circuit. All components are arranged in a compact layout to reduce signal attenuation and electromagnetic interference.

[0031] Among them, the magnetic latching relay 1 adopts the Panasonic HC2-DC12V type magnetic latching relay. As the core actuator, the magnetic latching relay 1 controls the number of coil turns of the autotransformer connected to the power grid by switching the main contact K1, thereby realizing the voltage regulation function. At the same time, the magnetic latching relay 1, in conjunction with the auxiliary contact module through mechanical linkage, provides real-time feedback signals to the action detection circuit.

[0032] The microcontroller used is the STMicroelectronics STM32F103C8T6, which features high performance and low power consumption, making it suitable for complex signal processing tasks. The microcontroller is electrically connected to the drive circuit, auxiliary contact module, and motion detection circuit via a PCB control board. As the core of the control system, it is responsible for signal processing, motion timing detection, and command output. It receives and analyzes signals from the auxiliary contact module and the main contact detection circuit to determine if the motion timing of the magnetic latching relay 1 is normal. Simultaneously, it controls the drive circuit to issue relay switching commands, ensuring accurate execution of the motion commands.

[0033] The drive circuit uses the ON Semiconductor MC33886 relay driver chip, which is positioned close to the magnetic latching relay 1 with a distance of ≤5cm to reduce signal attenuation and interference along the transmission path. The drive circuit is electrically connected to the magnetic latching relay 1 via wires. It amplifies the weak electrical signal from the microcontroller into a strong electrical signal capable of driving the magnetic latching relay 1, ensuring smooth relay switching operations. This achieves the goal of driving the magnetic latching relay 1 to complete the switching operation while minimizing signal attenuation and ensuring accurate execution of the action command.

[0034] The auxiliary contact module and the action detection circuit are electrically connected to the magnetic latching relay 1 via a contact switch assembly. The auxiliary contact module is a Schneider RXM2AB2BD type, which, through mechanical linkage and electrical connection, feeds back the contact operation status of the magnetic latching relay 1 to the control circuit in real time. The action detection circuit processes the signal provided by the auxiliary contact module and, in conjunction with the microcontroller, accurately detects the operating time of the magnetic latching relay 1 to determine if there is interference or abnormality. The contact switch assembly is used to achieve mechanical linkage between the contacts of the magnetic latching relay 1 and the auxiliary contact module, ensuring the consistency of their operation.

[0035] Furthermore, such as Figure 2 As shown, the motion detection circuit in this embodiment includes an optocoupler isolator, voltage divider resistors R1 and R2, and an RC filter circuit.

[0036] The optocoupler used is a Toshiba TLP250. Its input side is connected to the main contact K1 of the magnetic latching relay 1 via a wire, and its output side is connected to the microcontroller via a wire. The output side of the optocoupler has an independent grounding terminal. The optocoupler is used to achieve electrical isolation between high-voltage and low-voltage circuits, preventing interference from grid noise on the detection signal. Voltage divider resistors R1 and R2 are connected in series in the input circuit of the optocoupler to limit the current and divide the voltage on the input side, ensuring its operation within a safe range. The RC filter circuit includes a Yageo CFR-25JB-10K type resistor R3 and a Murata C1608X7R1C104K type filter capacitor C1. Resistor R3 is connected in series between the output of the optocoupler and the microcontroller for current limiting protection, ensuring safe signal transmission between the optocoupler output and the microcontroller. Filter capacitor C1 is connected in parallel between the optocoupler output and ground to filter out high-frequency noise and improve signal purity.

[0037] Furthermore, this embodiment designs a contact switch assembly for the electrical connection between the auxiliary contact module, the action detection circuit, and the magnetic latching relay 1. The specific structure is as follows:

[0038] like Figure 1 As shown, the contact switch assembly consists of a stainless steel connecting rod 2 and a spring plate 3, used to achieve mechanical linkage between the main contact K1 of the magnetic latching relay 1 and the auxiliary contact module. The main contact K1 of the magnetic latching relay 1 is connected to the auxiliary contact module via the stainless steel connecting rod 2. The stainless steel connecting rod 2 transmits the operating state of the main contact K1 to the auxiliary contact K2 in real time, thus ensuring synchronized operation. The auxiliary contact K2 makes elastic contact with the stainless steel connecting rod 2 via the spring plate 3. This design not only improves the stability of the mechanical linkage but also effectively reduces contact problems caused by vibration or wear. Furthermore, the auxiliary contact K2 is connected to the input side of the auxiliary contact module via a wire.

[0039] Through the above design, the contact switch assembly provides a stable and reliable signal transmission foundation while realizing the synchronous operation of the main contacts and auxiliary contacts, laying an important guarantee for accurately detecting the operating time of the magnetic latching relay 1.

[0040] Based on the magnetic latching relay action detection circuit and connection structure in the voltage regulator described above, its main functions are as follows:

[0041] During the switching process of the magnetic latching relay 1, inrush current and arcing can occur due to the potential difference across the coil, potentially leading to equipment damage or power grid failure. The magnetic latching relay action detection circuit and connection structure in this voltage regulator employ a synchronous switch, specifically the synchronous linkage between the main contact K1 and the auxiliary contact K2. By accurately measuring the action time of the magnetic latching relay 1, it ensures that the line voltage is near zero during relay switching, thus significantly reducing inrush current and arcing. The auxiliary contact module is mechanically linked to the main contact K1 via a stainless steel connecting rod 2. The contact surface is silver-plated, providing excellent conductivity and high-temperature resistance, ensuring stability and consistency during contact switching and reducing measurement anomalies caused by poor contact.

[0042] Because the detection circuit is susceptible to power grid interference, signal sampling is inaccurate, making it impossible to reliably determine the actual operating time of the magnetic latching relay 1. The magnetic latching relay operation detection circuit and its connection structure in this voltage regulator employ an anti-interference operation detection circuit composed of an optocoupler isolator, voltage divider resistors, and an RC filter circuit. This achieves electrical isolation between high-voltage and low-voltage circuits, avoiding interference from power grid noise. The RC filter circuit further suppresses high-frequency noise, improving signal purity.

[0043] Simultaneously with the closure of the main contact K1, the auxiliary contact K2 closes synchronously via the stainless steel connecting rod 2, triggering the auxiliary contact module to transmit data to the microcontroller's PB0 pin. At the same time, the status signal of the main contact generates a feedback signal through an optocoupler isolator, which is then filtered and transmitted to the microcontroller's PA1 pin. The microcontroller compares the time difference between the signals from the action detection circuit and the auxiliary contact module; the presence of a time difference indicates interference or an abnormality.

[0044] Due to the lack of effective anti-interference measures in the detection circuit, false positives or missed detections are prone to occur in complex power grid environments. The optocoupler, as a core component, completely isolates the high-voltage side from the low-voltage side, avoiding the impact of electromagnetic interference from the power grid on the detection circuit, significantly improving its anti-interference capability and ensuring the accuracy of signal sampling. The relay driver chip is installed close to the magnetically latched relay 1, reducing attenuation and interference along the signal transmission path.

[0045] Inrush current and arcing can cause relay contacts to stick or melt, affecting the normal operation and lifespan of the equipment. In this voltage regulator, the auxiliary contact K2 of the magnetic latching relay action detection circuit and connection structure is in elastic contact with the stainless steel connecting rod 2 through the spring plate 3, ensuring that the auxiliary contact operates in unison with the main contact, avoiding poor contact problems caused by mechanical vibration or wear, and improving the overall reliability of the equipment.

[0046] The above are merely preferred embodiments of this utility model, but the scope of protection of this utility model is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in this utility model, based on the technical solution and inventive concept of this utility model, should be included within the scope of protection of this utility model.

Claims

1. The magnetic latching relay action detection circuit and connection structure in a voltage regulator, characterized in that: The action detection circuit and connection structure are arranged inside the voltage regulator housing. The action detection circuit and connection structure are electrically connected to the voltage regulator's compensating autotransformer and heat dissipation device, together forming a complete voltage regulator system. The motion detection circuit and connection structure include a PCB control board and a magnetic latching relay. The PCB control board is equipped with a microcontroller, a drive circuit, an auxiliary contact module, and a motion detection circuit. The microcontroller is electrically connected to the drive circuit, auxiliary contact module, and motion detection circuit via a PCB control board. The drive circuit is electrically connected to the magnetic latching relay via wires, and the auxiliary contact module and motion detection circuit are electrically connected to the magnetic latching relay via contact switch assemblies.

2. The magnetic latching relay action detection circuit and connection structure in the voltage regulator according to claim 1, characterized in that: The motion detection circuit includes an optocoupler isolator, voltage divider resistors R1 and R2, and an RC filter circuit; The input side of the optocoupler is connected to the main contact K1 of the magnetic latching relay via a wire, and its output side is connected to the microcontroller via a wire. The output side of the optocoupler has an independent grounding terminal. Voltage divider resistors R1 and R2 are connected in series in the input circuit of the optocoupler. The RC filter circuit includes a filter capacitor C1 and a resistor R3. The resistor R3 is connected in series between the output terminal of the optocoupler and the microcontroller, and the filter capacitor C1 is connected in parallel between the output terminal of the optocoupler and ground.

3. The magnetic latching relay action detection circuit and connection structure in the voltage regulator according to claim 2, characterized in that: The contact switch assembly includes a stainless steel connecting rod, and the input side of the auxiliary contact module is connected to the auxiliary contact K2 via a wire; the main contact K1 of the magnetic latching relay is mechanically linked to the auxiliary contact module via the stainless steel connecting rod, and the stainless steel connecting rod transmits the action of the main contact K1 to the auxiliary contact K2.

4. The magnetic latching relay action detection circuit and connection structure in the voltage regulator according to claim 3, characterized in that: The auxiliary contact K2 is in elastic contact with the stainless steel connecting rod via a spring plate.

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