A three-phase in-line permanent magnet vacuum circuit breaker with manual closing function

Abstract

This application provides a three-phase single-phase in-line permanent magnet vacuum circuit breaker with manual closing function, relating to the field of electrical equipment control technology. This application sets up a first-stage voltage regulator circuit to rectify and initially regulate the input AC power supply voltage, outputting a first DC voltage. A second-stage voltage regulator circuit then further regulates the first DC voltage to obtain a more stable second DC voltage. A voltage conversion circuit then boosts the second DC voltage to the required third DC voltage, and the capacitor module is charged under the protection of a capacitor charging protection circuit. Finally, a drive circuit precisely controls the closing or opening action of the circuit breaker based on the voltage state of the capacitor module. This multi-stage voltage regulation and protection series design ensures the stability of each voltage level, thereby improving the reliability of the circuit breaker during manual closing operation.

Description

Technical Field

[0001] This application relates to the field of electrical equipment control technology, specifically to a three-phase single-phase in-line permanent magnet vacuum circuit breaker with manual closing function. Background Technology

[0002] The three-phase in-line permanent magnet vacuum circuit breaker is an important switching device used in medium-voltage overhead power distribution lines. This circuit breaker is driven by three independent permanent magnet mechanisms and features fast breaking speed, long service life, and maintenance-free operation. In power systems, this type of circuit breaker is mainly used for power system control and protection, playing a particularly important role in scenarios such as grid connection of new energy power generation and frequent switching of industrial power loads.

[0003] Currently, during power system operation, when a system fault causes a circuit breaker to trip, operators need to promptly investigate the fault and restore power supply. In some remote areas or under severe weather conditions, remote control closing may be impossible due to communication interruptions or other reasons. Existing three-permanent-magnet circuit breakers only support manual opening operations and lack manual closing functionality, which makes it impossible to restore power supply in a timely manner under special circumstances such as communication interruptions. Although there are circuit breakers on the market that use a single permanent magnet / spring dual mechanism to achieve manual closing, these circuit breakers are not only structurally complex but also perform poorly in short-circuit fault breaking time (generally exceeding 10ms), resulting in poor reliability in applications with high equipment stability requirements, such as new energy grid connection points. Summary of the Invention

[0004] This application provides a three-phase single-phase in-line permanent magnet vacuum circuit breaker with manual closing function, which can ensure the stability of voltage levels and thus improve the reliability of the circuit breaker during manual closing operation.

[0005] This application provides a three-phase single-phase in-line permanent magnet vacuum circuit breaker with manual closing function. The circuit breaker includes a primary voltage regulator circuit, a secondary voltage regulator circuit, a voltage conversion circuit, a capacitor charging protection circuit, and a drive circuit. The primary voltage regulator circuit, the secondary voltage regulator circuit, the voltage conversion circuit, the capacitor charging protection circuit, and the drive circuit are connected in series, wherein:

[0006] The first-stage voltage regulator circuit is used to rectify and perform the first voltage regulation on the input AC power supply voltage, and output the first DC voltage.

[0007] The secondary voltage regulator circuit is used to perform a second voltage regulation process on the first DC voltage to obtain a second DC voltage.

[0008] The voltage conversion circuit is used to boost the second DC voltage to a third DC voltage;

[0009] The capacitor charging protection circuit is used to protect the capacitor module of the circuit breaker during charging.

[0010] The driving circuit is used to drive the circuit breaker to complete the closing operation according to the voltage state of the capacitor module.

[0011] By adopting the above technical solution, a first-stage voltage regulator circuit rectifies and first-stage regulates the input AC power supply voltage, outputting a first DC voltage. A second-stage voltage regulator circuit then performs a second-stage regulation on the first DC voltage to obtain a more stable second DC voltage. A voltage conversion circuit then boosts the second DC voltage to the required third DC voltage, and the capacitor module is charged under the protection of a capacitor charging protection circuit. Finally, the drive circuit precisely controls the circuit breaker's closing or opening action based on the voltage state of the capacitor module. This multi-stage voltage regulation and protection series design not only ensures the stability of each voltage level but also prevents potential damage to the capacitor module during charging through a dedicated protection circuit. Furthermore, the drive circuit can intelligently control the circuit based on the actual voltage state of the capacitor module, thereby effectively improving the reliability of the circuit breaker during manual closing operations.

[0012] Optionally, the first-stage voltage regulator circuit includes a power transformer, a bridge rectifier, and a first voltage regulator unit, wherein:

[0013] The primary coil of the power transformer is connected to the power source, and the secondary coil of the power transformer is connected to the input terminal of the bridge rectifier.

[0014] The positive output terminal of the bridge rectifier is connected to the input terminal of the first voltage regulator unit, and the negative output terminal of the bridge rectifier is grounded.

[0015] The output terminal of the first voltage regulator unit is connected to the secondary voltage regulator circuit.

[0016] By adopting the above technical solution, the AC power input from the power transformer is stepped down. The reduced AC voltage is then input to a bridge rectifier for rectification, converting the AC power into pulsating DC power. The rectified voltage is then regulated by the first voltage regulator unit, outputting a stable DC voltage to the second-stage voltage regulator circuit. The power transformer's step-down function controls the system operating voltage within a suitable range. The bridge rectifier, using full-wave rectification, improves rectification efficiency and reduces ripple. The first voltage regulator unit further filters out ripple and provides a stable DC output.

[0017] Optionally, the first voltage regulator unit includes a voltage regulator, a first capacitor, a second capacitor, a first diode, a second diode, a first resistor, a second resistor, and a load resistor, wherein the second resistor is a variable resistor, and:

[0018] The first terminal of the voltage regulator is grounded via the second capacitor;

[0019] The third terminal of the voltage regulator is grounded through the first capacitor, and the third terminal of the voltage regulator is connected to the positive output of the bridge rectifier as the input terminal of the first voltage regulation unit.

[0020] The first end of the first resistor is connected to the second end of the voltage regulator, the second end of the first resistor is connected to the first end of the voltage regulator, and the second end of the first resistor is grounded through the second resistor;

[0021] The positive terminal of the second diode is connected to the second end of the first resistor, the negative terminal of the second diode is connected to the positive terminal of the first diode, and the negative terminal of the first diode is connected to the third end of the voltage regulator.

[0022] The first end of the load resistor is connected to the first end of the first resistor, the second end of the load resistor is grounded, and the first end of the load resistor serves as the output end of the first voltage regulator unit and is connected to the secondary voltage regulator circuit.

[0023] By adopting the above technical solution, the pulsating DC voltage output from the bridge rectifier is first input through the third terminal of the voltage regulator, and then filtered by the first capacitor to reduce input voltage ripple. The first terminal of the voltage regulator is grounded through the second capacitor to form a stable reference potential. The first resistor and the second resistor form a voltage divider network, where the second resistor is a variable resistor that can adjust the output voltage according to actual needs. The series configuration of the first diode and the second diode forms a protection circuit to prevent reverse current from damaging the voltage regulator when the input voltage is abnormal. The load resistor is connected to the first terminal of the first resistor and grounded, providing a stable output voltage while limiting the output current to avoid overload. This circuit structure enables the voltage regulator unit to convert the input pulsating DC voltage into a stable DC voltage output to the second-stage voltage regulator circuit, while also possessing overvoltage protection and adjustable output characteristics, improving the reliability and adaptability of the first-stage voltage regulator circuit.

[0024] Optionally, the first-stage voltage regulator circuit further includes a protection resistor, wherein:

[0025] The protective resistor is connected to the positive terminal of the secondary coil of the power transformer and the positive input terminal of the bridge rectifier, respectively.

[0026] By adopting the above technical solution, when the output voltage of the power transformer experiences instantaneous overvoltage or when the bridge rectifier generates inrush current at startup, the excess energy can be consumed by the protection resistor, limiting the rate of current change. This protects the bridge rectifier from damage caused by transient voltage and surge current, while also reducing the load impact on the power transformer.

[0027] Optionally, the secondary voltage regulator circuit includes a third capacitor, a fourth capacitor, a fifth capacitor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a third diode, a first transistor, a second transistor, and a third transistor, wherein the seventh resistor is a variable resistor, wherein:

[0028] The input terminal of the secondary voltage regulator circuit is grounded via the third capacitor;

[0029] The input terminal of the secondary voltage regulator circuit is connected to the collector of the second transistor and the collector of the third transistor, respectively. The base of the third transistor is grounded through the fourth capacitor, and the emitter of the third transistor is connected to the base of the second transistor.

[0030] The output terminal of the first-stage voltage regulator circuit is connected to the emitter of the first transistor via the third resistor, and the collector of the first transistor is connected to the emitter of the second transistor via the fourth resistor.

[0031] The negative terminal of the third diode is connected to the collector of the first transistor, and the positive terminal of the third diode is grounded.

[0032] The emitter of the second transistor is grounded via the fifth resistor, the seventh resistor, and the sixth resistor in series, and the base of the first transistor is connected to the sliding end of the seventh resistor;

[0033] The positive terminal of the fifth capacitor is connected to the emitter of the second transistor, the negative terminal of the fifth capacitor is grounded, and the positive terminal of the fifth capacitor serves as the output terminal of the secondary voltage regulator circuit and is connected to the capacitor charging protection circuit.

[0034] By adopting the above technical solution and employing a three-stage transistor amplifier structure, the input voltage is initially filtered by the third capacitor. The third and second transistors form a Darlington amplifier circuit, providing high-gain amplification, while the fourth capacitor stabilizes the base voltage of the third transistor. The first transistor, as the main regulating element, has its base voltage controlled by the sliding end of the seventh variable resistor. Adjusting the seventh resistor allows for precise adjustment of the output voltage. The third diode is grounded to provide clamping protection, preventing excessively high collector voltage of the first transistor. The voltage divider network formed by the fifth, seventh, and sixth resistors provides a suitable bias voltage for the transistors, while the fifth capacitor provides final filtering of the output voltage. This multi-stage amplification and precise adjustment design allows the second-stage voltage regulator circuit to further stabilize the output voltage of the first-stage regulator circuit, resulting in higher voltage regulation accuracy and stronger anti-interference capability, providing a stable and reliable DC voltage input for the subsequent capacitor charging protection circuit.

[0035] Optionally, the third diode is a Zener diode.

[0036] By adopting the above technical solution, when the collector voltage of the first transistor exceeds the breakdown voltage of the Zener diode, the Zener diode will conduct and clamp at its breakdown voltage value. This characteristic can not only provide overvoltage protection for the first transistor, but also provide a stable reference voltage for the secondary voltage regulator circuit by utilizing the constant voltage characteristic of the Zener diode, thereby improving the voltage regulation accuracy and reliability of the secondary voltage regulator circuit.

[0037] Optionally, the first transistor, the second transistor, and the third transistor are all NPN transistors.

[0038] By adopting the above technical solution, the common-emitter connection of the second and third transistors provides a larger current amplification factor, while the first transistor provides linear regulation capability. The coordinated operation of the three NPN transistors simplifies the bias design of the circuit and improves the reliability of the two-stage voltage regulator circuit.

[0039] Optionally, the capacitor charging protection circuit includes an eighth resistor, a ninth resistor, a fourth transistor, a fourth diode, and a load output resistor, wherein:

[0040] The positive input of the capacitor charging protection circuit is connected to the gate of the fourth transistor via the eighth resistor, and the drain and source of the fourth transistor are grounded.

[0041] The positive terminal of the fourth diode is grounded, and the negative terminal of the fourth diode is connected to the gate of the fourth transistor.

[0042] One end of the ninth resistor is connected to the gate of the fourth transistor, and the other end of the ninth resistor is grounded.

[0043] The positive output terminal of the capacitor charging protection circuit is grounded through the load output resistor.

[0044] By employing the above technical solution, the input current is limited by the eighth resistor, providing a suitable driving voltage for the gate of the fourth transistor. The cooperation of the fourth diode and the ninth resistor forms a gate protection network to prevent damage to the fourth transistor due to excessive gate voltage. When the input voltage increases, the fourth transistor gradually turns on, shunting the charging current through the low-impedance path between its drain and source. At the same time, the load output resistor provides a stable output voltage while limiting the output current. This structure can protect the capacitor module from shocks during the charging process.

[0045] Optionally, the fourth diode is a breakdown diode.

[0046] By adopting the above technical solution, when a momentary overvoltage occurs at the gate voltage of the fourth transistor, the breakdown diode will quickly conduct and conduct excess energy to the ground wire. Its fast response characteristics and good surge absorption capability can effectively prevent the gate of the fourth transistor from being damaged due to overvoltage.

[0047] Optionally, the driving circuit includes a first driving chip, a second driving chip, and an IGBT module, wherein:

[0048] The IGBT module is connected to the first driver chip and the second driver chip respectively; the first driver chip and the second driver chip drive the IGBT module to drive the circuit breaker to complete the closing operation according to the charging voltage of the capacitor module.

[0049] By adopting the above technical solutions, the IGBT module can achieve fast switching and precise current control under the control of the drive signal. Its excellent switching characteristics and low loss characteristics ensure the speed and reliability of the circuit breaker closing operation.

[0050] In summary, the beneficial effects of the technical solution of this application include:

[0051] By adopting the above technical solution, a first-stage voltage regulator circuit rectifies and first-stage regulates the input AC power supply voltage, outputting a first DC voltage. A second-stage voltage regulator circuit then performs a second-stage regulation on the first DC voltage to obtain a more stable second DC voltage. A voltage conversion circuit then boosts the second DC voltage to the required third DC voltage, and the capacitor module is charged under the protection of a capacitor charging protection circuit. Finally, the drive circuit precisely controls the circuit breaker's closing or opening action based on the voltage state of the capacitor module. This multi-stage voltage regulation and protection series design not only ensures the stability of each voltage level but also prevents potential damage to the capacitor module during charging through a dedicated protection circuit. Furthermore, the drive circuit can intelligently control the circuit based on the actual voltage state of the capacitor module, thereby effectively improving the reliability of the circuit breaker during manual closing operations. Attached Figure Description

[0052] Figure 1 This is a schematic diagram of a three-phase single-phase in-line permanent magnet vacuum circuit breaker with manual closing function provided in an embodiment of this application;

[0053] Figure 2 This is a schematic diagram of a first-stage voltage regulator circuit provided in an embodiment of this application;

[0054] Figure 3 This is a schematic diagram of a two-stage voltage regulator circuit provided in an embodiment of this application;

[0055] Figure 4This is a schematic diagram of a capacitor charging protection circuit provided in an embodiment of this application.

[0056] Explanation of reference numerals in the attached diagram: C1, first capacitor; C2, second capacitor; C3, third capacitor; C4, fourth capacitor; C5, fifth capacitor; R1, first resistor; R2, second resistor; R3, third resistor; R4, fourth resistor; R5, fifth resistor; R6, sixth resistor; R7, seventh resistor; R8, eighth resistor; R9, ninth resistor; R0, protection resistor; R1, load resistor; Rload, load output resistor; Q1, first transistor; Q2, second transistor; Q3, third transistor; Q4, fourth transistor; D1, first diode; D2, second diode; D3, third diode; D4, fourth diode. Detailed Implementation

[0057] To enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification 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.

[0058] In the description of the embodiments of this application, words such as "illustrative," "for example," or "for example" are used to indicate examples, illustrations, or explanations. Any embodiment or design described as "illustrative," "for example," or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design solutions. Rather, the use of words such as "illustrative," "for example," or "for example" is intended to present the relevant concepts in a specific manner.

[0059] In the description of the embodiments of this application, the term "multiple" means two or more. For example, multiple systems means two or more systems, and multiple screen terminals means two or more screen terminals. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. The terms "comprising," "including," "having," and variations thereof all mean "including but not limited to," unless otherwise specifically emphasized.

[0060] Please see Figure 1 This is a schematic diagram of a three-phase in-line permanent magnet vacuum circuit breaker with manual closing function provided in an embodiment of this application.

[0061] Combination Figure 1First, a brief explanation of the working principle of this application is given. A manual closing mechanism is added to the existing permanent magnet circuit breaker, independent of the existing manual opening mechanism. The external manual closing handle (similar to the external spring closing mechanism) is pulled up and down, driving the permanent magnet AC generator via a gearbox. The output AC power voltage is rectified, filtered, and regulated by a first-stage voltage regulator circuit to obtain a relatively stable first DC voltage. A second-stage voltage regulator circuit then provides a stable second DC voltage. This second DC voltage is boosted to a third DC voltage by a DC / DC converter module and then charged by a pre-installed capacitor charging protection module to the dedicated closing capacitor for the closing mechanism. When the capacitor module voltage exceeds the discharge threshold (typically set to DC 230V), the IGBT driver chip is activated, and the capacitor discharges to the permanent magnet coil, completing the closing operation.

[0062] The following is a detailed description of the specific structure of a three-phase single-phase in-line permanent magnet vacuum circuit breaker with manual closing function provided in this application.

[0063] The circuit breaker includes a primary voltage regulator circuit, a secondary voltage regulator circuit, a voltage conversion circuit, a capacitor charging protection circuit, and a drive circuit. These components are connected in series.

[0064] The first-stage voltage regulator circuit is used to rectify and regulate the input AC power supply voltage, and output the first DC voltage.

[0065] A two-stage voltage regulator circuit is used to perform a second voltage regulation process on the first DC voltage to obtain a second DC voltage.

[0066] A voltage conversion circuit is used to boost the second DC voltage to a third DC voltage;

[0067] A capacitor charging protection circuit is used to protect the capacitor module of the circuit breaker during charging.

[0068] The drive circuit is used to drive the circuit breaker to close based on the voltage state of the capacitor module.

[0069] Specifically, the first-stage voltage regulator circuit receives the AC power voltage generated by the manually operated permanent magnet generator, converts the AC power into pulsating DC power through a rectifier circuit, and then filters and regulates it to output a relatively stable first DC voltage. The second-stage voltage regulator circuit receives the first DC voltage and uses a more precise voltage regulation circuit to further adjust and stabilize the voltage, outputting a second DC voltage with smaller fluctuations and higher stability. The voltage conversion circuit uses DC / DC conversion technology to boost the stable DC voltage output from the second-stage regulator to a higher voltage level required for capacitor module charging, outputting a third DC voltage. The capacitor charging protection circuit plays a protective role during the capacitor module charging process. The drive circuit, based on the voltage state of the capacitor module, drives the circuit breaker to complete the closing operation when the voltage reaches a preset threshold.

[0070] Based on the above embodiments, as an optional implementation method, please refer to... Figure 2 This is a schematic diagram of a first-stage voltage regulator circuit provided in an embodiment of this application. The first-stage voltage regulator circuit includes a power transformer, a bridge rectifier, and a first voltage regulating unit, wherein:

[0071] The primary coil of the power transformer is connected to the power supply, and the secondary coil of the power transformer is connected to the input terminal of the bridge rectifier.

[0072] The positive output terminal of the bridge rectifier is connected to the input terminal of the first voltage regulator unit, and the negative output terminal of the bridge rectifier is grounded.

[0073] The output of the first voltage regulator unit is connected to the second voltage regulator circuit.

[0074] In practice, the primary coil of the power transformer is connected to the AC power source generated by manual operation. Since the voltage amplitude generated by manual operation may fluctuate significantly, the power transformer, while providing electrical isolation, converts the input voltage to a suitable level. The AC voltage output from its secondary coil is connected to the input terminal of the bridge rectifier.

[0075] The bridge rectifier employs a full-wave rectifier circuit. Its input terminal receives the AC voltage output from the secondary coil of the power transformer. Four diodes rectify the AC voltage into unidirectional pulsating DC voltage. The rectified voltage is output from the positive terminal of the bridge rectifier, which is connected to the input terminal of the first voltage regulator unit. In this unit, voltage regulators filter and regulate the rectified voltage. The output of the first voltage regulator unit is connected to a secondary voltage regulator circuit, providing a relatively stable DC voltage input for subsequent fine voltage regulation.

[0076] Based on the above embodiments, as an optional implementation, the first voltage regulator unit includes a voltage regulator, a first capacitor, a second capacitor, a first diode, a second diode, a first resistor, a second resistor, and a load resistor, wherein the second resistor is a variable resistor, wherein:

[0077] The first terminal of the voltage regulator is grounded via the second capacitor;

[0078] The third terminal of the voltage regulator is grounded through the first capacitor, and the third terminal of the voltage regulator is connected to the positive output of the bridge rectifier as the input terminal of the first voltage regulation unit.

[0079] The first end of the first resistor is connected to the second end of the voltage regulator, the second end of the first resistor is connected to the first end of the voltage regulator, and the second end of the first resistor is grounded through the second resistor.

[0080] The positive terminal of the second diode is connected to the second end of the first resistor, the negative terminal of the second diode is connected to the positive terminal of the first diode, and the negative terminal of the first diode is connected to the third end of the voltage regulator.

[0081] The first end of the load resistor is connected to the first end of the first resistor, the second end of the load resistor is grounded, and the first end of the load resistor is connected to the output end of the first voltage regulator unit and the second voltage regulator circuit.

[0082] The first voltage regulator unit employs a composite voltage regulator circuit design based on a voltage regulator. Through the coordinated operation of multiple capacitors, diodes, and resistors, it effectively regulates the output voltage of the bridge rectifier. Its third terminal serves as the input terminal, receiving the pulsating DC voltage output from the bridge rectifier and grounded through the first capacitor for input filtering. The first terminal of the voltage regulator is grounded through the second capacitor to suppress high-frequency ripple at the output, improving the voltage regulation effect. A first resistor is connected between the first and second terminals of the voltage regulator, forming the basic bias circuit of the voltage regulator. The other end of the first resistor (the second terminal) is grounded through a variable resistor (the second resistor). This design allows for fine-tuning of the operating point of the voltage regulator circuit by adjusting the resistance value of the second resistor, improving the circuit's adaptability and voltage regulation accuracy. To provide additional voltage regulation protection, a protection branch consisting of a first diode and a second diode is added to the circuit. The anode of the second diode is connected to the second terminal of the first resistor, and its cathode is connected to the anode of the first diode. The cathode of the first diode is connected to the input terminal (the third terminal) of the voltage regulator. This diode branch provides effective clamping protection against abnormal input voltage fluctuations, preventing overvoltage damage to the circuit. The load resistor serves as both the load for the voltage regulator circuit and a voltage sampling resistor. Its first terminal is connected to the first terminal of the first resistor and acts as the output terminal of the first voltage regulator unit, connecting to the secondary voltage regulator circuit. The second terminal is grounded to complete the loop. Through the load resistor, a stable output voltage can be obtained, providing a reliable input for the subsequent secondary voltage regulator circuit.

[0083] Based on the above embodiments, as an optional implementation, the first-stage voltage regulator circuit further includes a protection resistor, wherein:

[0084] The protection resistors are connected to the positive terminal of the secondary coil of the power transformer and the positive input terminal of the bridge rectifier, respectively.

[0085] In practice, a protective resistor is connected in series between the positive terminal of the secondary coil of the power transformer and the positive input terminal of the bridge rectifier. When a momentary peak occurs in the output voltage of the secondary coil of the power transformer, the protective resistor can promptly limit the sudden change in current and dissipate the impact energy as heat, thereby protecting the bridge rectifier from damage caused by excessive current.

[0086] Please see Figure 3 , Figure 3 This is a schematic diagram of a two-stage voltage regulator circuit provided in an embodiment of this application. The following will be combined with... Figure 3 The two-stage voltage regulator circuit is described in detail.

[0087] The secondary voltage regulator circuit includes a third capacitor, a fourth capacitor, a fifth capacitor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a third diode, a first transistor, a second transistor, and a third transistor. The seventh resistor is a variable resistor.

[0088] The input terminal of the two-stage voltage regulator circuit is grounded via a third capacitor;

[0089] The input terminals of the two-stage voltage regulator circuit are connected to the collectors of the second transistor and the third transistor, respectively. The base of the third transistor is grounded through the fourth capacitor, and the emitter of the third transistor is connected to the base of the second transistor.

[0090] The output of the first-stage voltage regulator circuit is connected to the emitter of the first transistor via a third resistor, and the collector of the first transistor is connected to the emitter of the second transistor via a fourth resistor.

[0091] The negative terminal of the third diode is connected to the collector of the first transistor, and the positive terminal of the third diode is grounded.

[0092] The emitter of the second transistor is grounded via the fifth, seventh, and sixth resistors in series, and the base of the first transistor is connected to the sliding end of the seventh resistor.

[0093] The positive terminal of the fifth capacitor is connected to the emitter of the second transistor, the negative terminal of the fifth capacitor is grounded, and the positive terminal of the fifth capacitor is connected to the capacitor charging protection circuit as the output terminal of the secondary voltage regulator circuit.

[0094] Specifically, the AC signal at the input terminal undergoes preliminary filtering via a capacitor connected to ground before entering the main voltage regulator circuit, which consists of three transistors. In the main circuit, the collectors of the third and second transistors are directly connected to the input terminal. The base of the third transistor is grounded through a filter capacitor to obtain a stable bias, and its emitter is connected to the base of the second transistor to form a driving relationship. This connection method allows the third transistor to provide a stable base drive voltage for the second transistor.

[0095] The first transistor receives the input signal through a current-limiting resistor, and its collector is connected to the emitter of the second transistor through another resistor. To protect the first transistor from reverse voltage damage, a third diode is connected in parallel with its collector, and the positive terminal of the third diode is grounded to form a protection branch.

[0096] In the bias section, a structure of three resistors connected in series and grounded is adopted, with a variable resistor in the middle. The base of the first transistor is connected to the sliding contact of this variable resistor. By adjusting the position of the sliding contact, the operating point of the first transistor can be precisely controlled, thereby achieving fine-tuning of the entire voltage regulator circuit. When the output second DC voltage is too high, the base-emitter voltage decreases, the second transistor conducts less, and the third transistor current decreases, thus reducing the second output voltage. When the output second DC voltage is too low, the base-emitter voltage increases, the transistor conducts more, thus increasing the second output voltage. A large-capacity capacitor is used at the output of the two-stage voltage regulator circuit, and the second capacitor acts as a filter.

[0097] Optionally, the third diode is a Zener diode.

[0098] Unlike ordinary diodes, Zener diodes possess unique reverse breakdown characteristics. When the reverse voltage reaches its Zener voltage, a stable Zener breakdown occurs, at which point the voltage across the diode remains relatively constant. In a two-stage voltage regulator circuit, a third diode is connected in parallel between the collector of the first transistor and ground, with its anode grounded. This connection method puts it in a reverse-biased state. When the collector voltage of the first transistor attempts to exceed the Zener voltage due to certain reasons (such as sudden load changes or input voltage fluctuations), the Zener diode immediately conducts, clamping the excessive voltage to the Zener voltage value, thus providing dual protection.

[0099] Optionally, the first transistor, the second transistor, and the third transistor are all NPN transistors.

[0100] In this transistor, the collector of the third transistor is directly connected to the input power supply, while the base is grounded through a capacitor to obtain a stable bias. When there is a positive voltage at the base, current flows from the collector to the emitter. The changing input voltage causes a small change in the base voltage, which is amplified and generates a corresponding current change at the emitter. The emitter is directly connected to the base of the second transistor, forming a driving relationship.

[0101] The second transistor receives the voltage from the emitter of the third transistor as its base bias. When the emitter voltage of the third transistor changes, the base voltage of the second transistor also changes. An increase in the base voltage increases the transistor's conduction level, causing the collector-emitter current to increase; a decrease in the base voltage decreases the conduction level, and the current decreases accordingly.

[0102] The base of the first transistor is connected to the sliding end of a variable resistor, and the base voltage can be controlled by adjusting it. Its collector is connected to the emitter of the second transistor. When the base voltage rises, the transistor's conduction level increases, and the collector current increases; when the base voltage falls, the conduction level decreases, and the collector current decreases.

[0103] The series connection of three NPN transistors forms a complete feedback loop. Changes in the input voltage are first detected and amplified by the third transistor, then regulated by the second transistor, and finally precisely controlled by the first transistor. This design utilizes the current amplification characteristics of NPN transistors.

[0104] In this embodiment, the voltage conversion circuit is a DC boost circuit, and its circuit structure can adopt a typical boost topology.

[0105] One optional implementation is as follows: the voltage conversion circuit consists of components such as an input filter capacitor, a MOSFET switch, a power inductor, a fast recovery diode, and an output filter capacitor. The input filter capacitor is used to filter out the input voltage ripple, and a fuse is provided at the input for overcurrent protection. The core control of the circuit uses a PWM controller, which adjusts the switching duty cycle of the MOSFET to achieve voltage boosting and regulation.

[0106] The specific working principle is as follows: When the MOSFET is turned on, the input power supply stores energy through the inductor, and the inductor current gradually increases, while the output capacitor provides energy to the load. When the MOSFET is turned off, the energy stored in the inductor is released into the output capacitor and the load through the fast recovery diode, at which point the output voltage increases. By controlling the switching sequence of the MOSFET, the conversion from input voltage to a higher output voltage can be achieved.

[0107] Please see Figure 4 , Figure 4 This is a schematic diagram of a capacitor charging protection circuit provided in an embodiment of this application. The following will be combined with... Figure 4 The capacitor charging protection circuit is described in detail.

[0108] The capacitor charging protection circuit includes an eighth resistor, a ninth resistor, a fourth transistor, a fourth diode, and a load output resistor, wherein:

[0109] The positive input of the capacitor charging protection circuit is connected to the gate of the fourth transistor via the eighth resistor, and the drain and source of the fourth transistor are grounded.

[0110] The positive terminal of the fourth diode is grounded, and the negative terminal of the fourth diode is connected to the gate of the fourth transistor.

[0111] One end of the ninth resistor is connected to the gate of the fourth transistor, and the other end of the ninth resistor is grounded.

[0112] The positive output terminal of the capacitor charging protection circuit is grounded through the load output resistor.

[0113] This capacitor charging protection circuit is designed primarily to prevent overshoot during capacitor charging and to protect downstream circuitry. In its implementation, the positive input terminal is first connected to the gate of the fourth transistor via an eighth resistor, which limits the current and prevents excessive gate current. The fourth transistor is a MOSFET device with both its drain and source grounded, allowing it to quickly conduct and discharge excess charge under controlled conditions.

[0114] To protect the gate of the fourth transistor from reverse voltage damage, a fourth diode is connected in parallel at the gate, with its anode grounded and its cathode connected to the gate of the fourth transistor. When a reverse voltage occurs, the diode conducts, clamping the reverse voltage and effectively protecting the MOSFET gate. Simultaneously, a ninth resistor is connected between the gate of the fourth transistor and ground, forming a stable gate bias network. This ensures that the transistor remains in a defined state when there is no input signal, preventing gate voltage drift and malfunctions.

[0115] At the output terminal, the positive terminal of the circuit is grounded through a load output resistor. This resistor limits the output current and also provides a buffering effect when the load changes. When the input voltage rises, the fourth transistor adjusts its conduction state according to the change in gate voltage, thereby controlling the magnitude of the charging current. In case of overvoltage, the fourth transistor increases its conduction level to conduct excess charge to ground, thus providing protection.

[0116] Optionally, the fourth diode is a breakdown diode.

[0117] In practical applications, the selection of a breakdown diode needs to consider the maximum gate voltage of the fourth transistor. Typically, a device with a breakdown voltage slightly lower than the maximum gate voltage is chosen. This ensures that when an abnormal voltage occurs, the breakdown diode will conduct before the gate voltage reaches a dangerous value, limiting the excessive voltage to a safe range. Because the breakdown diode has an extremely fast response speed, completing the conduction process on the order of nanoseconds, it effectively prevents transient overvoltages from damaging the fourth transistor.

[0118] By using a breakdown diode, this protection circuit achieves more precise voltage control and more reliable protection. When the system is operating normally, the breakdown diode is in a high-impedance state and does not affect the normal operation of the circuit; when an abnormality occurs, the breakdown diode can quickly conduct, diverting excess energy to ground.

[0119] Based on the above embodiments, as an optional implementation, the driving circuit includes a first driving chip, a second driving chip, and an IGBT module, wherein:

[0120] The IGBT module is connected to the first driver chip and the second driver chip respectively; the first driver chip and the second driver chip drive the IGBT module to drive the circuit breaker to complete the closing operation according to the charging voltage of the capacitor module.

[0121] In practice, both the first and second driver chips are directly connected to the IGBT module. They receive the charging voltage signal from the capacitor module and adjust the timing and strength of the drive signal based on this voltage value. When the charging voltage of the capacitor module reaches a preset value, both driver chips output drive signals simultaneously, ensuring that the IGBT module can quickly and stably enter the conduction state. After receiving the drive signal, the IGBT module is responsible for converting the electrical energy stored in the capacitor module into the current that drives the circuit breaker to close.

[0122] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0123] The above description is merely an exemplary embodiment of this disclosure and should not be construed as limiting the scope of this disclosure. Any equivalent changes and modifications made in accordance with the teachings of this disclosure shall still fall within the scope of this disclosure. Those skilled in the art will readily conceive of other embodiments of this disclosure upon considering the specification and the disclosure of practical truths. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not described in this disclosure.

Claims

1. A three-phase single-phase in-line permanent magnet vacuum circuit breaker with manual closing function, characterized in that, The circuit breaker includes a primary voltage regulator circuit, a secondary voltage regulator circuit, a voltage conversion circuit, a capacitor charging protection circuit, and a drive circuit. The primary voltage regulator circuit, the secondary voltage regulator circuit, the voltage conversion circuit, the capacitor charging protection circuit, and the drive circuit are connected in series. The capacitor module of the circuit breaker is connected to the capacitor charging protection circuit and the drive circuit respectively. The primary voltage regulator circuit is connected to a permanent magnet AC generator. Wherein: The first-stage voltage regulator circuit is used to rectify and regulate the input AC power supply voltage, and output the first DC voltage. The AC power supply voltage is generated by pulling the handle and lifting ring to drive the permanent magnet AC generator. The secondary voltage regulator circuit is used to perform a second voltage regulation process on the first DC voltage to obtain a second DC voltage. The voltage conversion circuit is used to boost the second DC voltage to a third DC voltage, and the third DC voltage charges the capacitor module of the circuit breaker through the capacitor charging protection circuit. The capacitor charging protection circuit is used to protect the capacitor module of the circuit breaker during charging. The driving circuit is used to drive the circuit breaker to complete the closing operation according to the voltage state of the capacitor module.

2. The three-phase single-phase in-line permanent magnet vacuum circuit breaker with manual closing function according to claim 1, characterized in that, The primary voltage regulator circuit includes a power transformer, a bridge rectifier, and a first voltage regulator unit, wherein: The primary coil of the power transformer is connected to the power source, and the secondary coil of the power transformer is connected to the input terminal of the bridge rectifier. The positive output terminal of the bridge rectifier is connected to the input terminal of the first voltage regulator unit, and the negative output terminal of the bridge rectifier is grounded. The output terminal of the first voltage regulator unit is connected to the secondary voltage regulator circuit.

3. The three-phase single-phase in-line permanent magnet vacuum circuit breaker with manual closing function according to claim 2, characterized in that, The first voltage regulator unit includes a voltage regulator, a first capacitor, a second capacitor, a first diode, a second diode, a first resistor, a second resistor, and a load resistor, wherein the second resistor is a variable resistor. The first terminal of the voltage regulator is grounded via the second capacitor; The third terminal of the voltage regulator is grounded through the first capacitor, and the third terminal of the voltage regulator is connected to the positive output of the bridge rectifier as the input terminal of the first voltage regulation unit. The first end of the first resistor is connected to the second end of the voltage regulator, the second end of the first resistor is connected to the first end of the voltage regulator, and the second end of the first resistor is grounded through the second resistor; The positive terminal of the second diode is connected to the second end of the first resistor, the negative terminal of the second diode is connected to the positive terminal of the first diode, and the negative terminal of the first diode is connected to the third end of the voltage regulator. The first end of the load resistor is connected to the first end of the first resistor, the second end of the load resistor is grounded, and the first end of the load resistor serves as the output end of the first voltage regulator unit and is connected to the secondary voltage regulator circuit.

4. The three-phase single-phase in-line permanent magnet vacuum circuit breaker with manual closing function according to claim 2, characterized in that, The primary voltage regulator circuit also includes a protection resistor, wherein: The protective resistor is connected to the positive terminal of the secondary coil of the power transformer and the positive input terminal of the bridge rectifier, respectively.

5. The three-phase single-phase in-line permanent magnet vacuum circuit breaker with manual closing function according to claim 1, characterized in that, The secondary voltage regulator circuit includes a third capacitor, a fourth capacitor, a fifth capacitor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a third diode, a first transistor, a second transistor, and a third transistor. The seventh resistor is a variable resistor. The input terminal of the secondary voltage regulator circuit is grounded via the third capacitor; The input terminal of the secondary voltage regulator circuit is connected to the collector of the second transistor and the collector of the third transistor, respectively. The base of the third transistor is grounded through the fourth capacitor, and the emitter of the third transistor is connected to the base of the second transistor. The output terminal of the first-stage voltage regulator circuit is connected to the emitter of the first transistor via the third resistor, and the collector of the first transistor is connected to the emitter of the second transistor via the fourth resistor. The negative terminal of the third diode is connected to the collector of the first transistor, and the positive terminal of the third diode is grounded. The emitter of the second transistor is grounded via the fifth resistor, the seventh resistor, and the sixth resistor in series, and the base of the first transistor is connected to the sliding end of the seventh resistor; The positive terminal of the fifth capacitor is connected to the emitter of the second transistor, the negative terminal of the fifth capacitor is grounded, and the positive terminal of the fifth capacitor serves as the output terminal of the secondary voltage regulator circuit and is connected to the capacitor charging protection circuit.

6. The three-phase single-phase in-line permanent magnet vacuum circuit breaker with manual closing function according to claim 5, characterized in that, The third diode is a Zener diode.

7. The three-phase single-phase in-line permanent magnet vacuum circuit breaker with manual closing function according to claim 5, characterized in that, The first transistor, the second transistor, and the third transistor are all NPN transistors.

8. The three-phase single-phase in-line permanent magnet vacuum circuit breaker with manual closing function according to claim 1, characterized in that, The capacitor charging protection circuit includes an eighth resistor, a ninth resistor, a fourth transistor, a fourth diode, and a load output resistor, wherein: The positive input of the capacitor charging protection circuit is connected to the gate of the fourth transistor via the eighth resistor, and the drain and source of the fourth transistor are grounded. The positive terminal of the fourth diode is grounded, and the negative terminal of the fourth diode is connected to the gate of the fourth transistor. One end of the ninth resistor is connected to the gate of the fourth transistor, and the other end of the ninth resistor is grounded. The positive output terminal of the capacitor charging protection circuit is grounded through the load output resistor.

9. The three-phase single-phase in-line permanent magnet vacuum circuit breaker with manual closing function according to claim 8, characterized in that, The fourth diode is a breakdown diode.

10. The three-phase single-phase in-line permanent magnet vacuum circuit breaker with manual closing function according to claim 1, characterized in that, The driving circuit includes a first driving chip, a second driving chip, and an IGBT module, wherein: The IGBT module is connected to the first driver chip and the second driver chip respectively; the first driver chip and the second driver chip drive the IGBT module to drive the circuit breaker to complete the closing operation according to the charging voltage of the capacitor module.

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