A high voltage one-in-two protection switch assembly system

Abstract

The present application relates to the technical field of high-voltage switch box, solves the technical problem that the existing switch box is easy to appear misjudgment, misjudgment and mutual interference when facing flashover failure, especially relates to a high-voltage one-to-two protection switch assembly system, which has a charging machine as a high-voltage charging power supply and a rear-stage load module composed of multiple positive high-voltage capacitors and negative high-voltage capacitors, comprising: a protection switch assembly, the output end of the charging machine is connected with the input end of the protection switch assembly, the protection switch assembly is used for connecting the charging machine and the rear-stage load module, and the rear-stage load module is turned on during charging and is disconnected during discharging.The switch box provided by the present application will not appear misjudgment and misjudgment when facing flashover failure, at the same time, all input and output signals are converted into optical signals for transmission, including charging voltage signals which are converted into optical signals through V / F conversion, the anti-interference ability of the signals is enhanced, thereby the reliability of the switch box is enhanced.

Description

Technical Field

[0001] This invention relates to the field of high voltage switch box technology, and in particular to a high voltage one-to-two protection switch assembly system. Background Technology

[0002] High-voltage switchgear is one of the key pieces of equipment in power systems, mainly used for functions such as power transmission and distribution interruption, isolation, transformation, and protection. With the rapid development of urbanization and industrialization, cities are becoming increasingly larger, and the demand for electricity is also increasing. As a key device for urban power supply, high-voltage switchgear plays a reliable role in power supply, protection, and control. Therefore, the application prospects of high-voltage switchgear in urban power supply will grow exponentially.

[0003] Currently, the most commonly used switch boxes are oil-immersed, which have the following disadvantages during use:

[0004] 1. A dual-loop detection system using voltage and current is adopted. However, because the current Hall effect sensor requires a very small current (8mA), sampling of the current Hall effect sensor becomes difficult (the minimum current Hall effect sensor is 200mA). Therefore, the comparison threshold has to be increased to avoid false alarms. As a result, current sampling becomes virtually ineffective.

[0005] 2. The voltage is divided by a voltage divider. Although it can sample flashover conditions, it is also easily affected by interference from adjacent circuits, which may cause other unrelated circuits to trip when a fault is detected on one circuit.

[0006] 3. The control circuit has significant problems. In the field, one of the circuits may become uncontrollable, and the host computer's control relay will not operate. The problem can only be solved by replacing the branch detection board or the optocoupler on the main control board. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides a high-voltage one-to-two protection switch assembly system, which solves the technical problems of missed detection, false detection, and mutual interference that occur in existing switch boxes when facing flashover faults.

[0008] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a high-voltage one-to-two protection switch assembly system, comprising a charger as a high-voltage charging power supply, and a downstream load module composed of multiple positive high-voltage capacitors and negative high-voltage capacitors, including:

[0009] The output terminal of the charger is connected to the input terminal of the protection switch assembly. The protection switch assembly is used to connect the charger and the downstream load module. It connects the downstream load module during charging and disconnects the downstream load module during discharging. It also monitors the voltage parameters of the downstream load module in real time and identifies the fault status.

[0010] The host computer establishes communication with the protection switch assembly through a serial port server and is used to display the voltage, current and flashover fault status of the protection switch assembly.

[0011] Furthermore, the protection switch assembly includes a total of ten positive high-voltage protection switch units and negative high-voltage protection switch units, as well as a detection and control module for controlling the corresponding on / off states of the positive high-voltage protection switch units and negative high-voltage protection switch units based on their voltage, current, and flashover fault status.

[0012] Furthermore, the positive high voltage protection switch unit and the negative high voltage protection switch unit are electrically connected to the charger via positive and negative high voltage charging lines, respectively. The positive high voltage protection switch unit and the negative high voltage protection switch unit are used to switch on and off the corresponding ten positive high voltage capacitors and negative high voltage capacitors, respectively.

[0013] Furthermore, the detection and control module communicates with the host computer via optical fiber using the RS232 protocol, and is used to receive and send control commands and status parameters of the protection switch components.

[0014] Furthermore, the protection switch assembly also includes a total of five sets of one-to-two switch units, and an oil-immersed high-voltage relay electrically connected to the one-to-two switch units. Each set of one-to-two switch units includes a positive high-voltage one-to-two isolation unit and a negative high-voltage one-to-two isolation unit.

[0015] Furthermore, the protection switch assembly also includes a detection and control module for controlling the corresponding on / off states of the positive high voltage one-to-two isolation unit and the negative high voltage one-to-two isolation unit based on their voltage, current, and flashover fault status.

[0016] Furthermore, the two oil-immersed high-voltage relays are electrically connected to the charger via positive and negative high-voltage charging lines, respectively. The positive high-voltage one-to-two isolation unit and the negative high-voltage one-to-two isolation unit are used to switch on and off their corresponding two positive high-voltage capacitors and negative high-voltage capacitors, respectively.

[0017] Furthermore, the positive high voltage one-to-two isolation unit includes a leakage protection resistor and a Hall current sensor connected in sequence to the output terminal of the oil-immersed high voltage relay. An isolation diode is connected in parallel across the two ends of the leakage protection resistor to prevent reverse voltage during charging and discharging. An anti-series diode and a voltage divider are connected in parallel between the leakage protection resistor and the Hall current sensor to detect the charging voltage and charging current in real time, and the other end of the voltage divider is grounded.

[0018] Furthermore, the oil-immersed high-voltage relay includes a single-pole double-throw disconnector, in which one of the contacts is grounded through a grounding resistor.

[0019] Furthermore, the detection and control module includes a fault detection module and a control module that establish a communication connection with each other. The control module is used to receive fault signals from each protection switch component detected by the fault detection module and make control decisions. The fault detection module includes a relay control circuit and a fault judgment and V / F conversion circuit.

[0020] By employing the above technical solution, the present invention provides a high-voltage one-to-two protection switch assembly system, which has at least the following beneficial effects:

[0021] 1. The switch box proposed in this invention has load voltage detection and flashover fault detection functions. It can transmit data such as switch status, flashover status and load voltage to the host computer. The host computer can realize functions such as on / off control, energy discharge, flashover disconnection and voltage maintenance. During the charging process, the load flashover fault detection will not have missed detection or false detection, and can quickly disconnect. Therefore, the positive and negative polarity protection switches of the same load can be linked, and the operation of protection switches of different loads does not affect each other. Moreover, one protection switch component can simultaneously isolate and protect two loads.

[0022] 2. The switch box provided by this invention will not misjudge or miss a flashover fault. The flashover fault is detected by simultaneously detecting the charging voltage and the charging current, which is equivalent to double protection. At the same time, all input and output signals are converted into optical signals for transmission. Including the charging voltage signal, which is converted into an optical signal through V / F conversion, the anti-interference ability of the signal is enhanced, thereby enhancing the reliability of the switch box. Attached Figure Description

[0023] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0024] Figure 1 This is a system structure block diagram of the protection switch assembly in Embodiment 1 of the present invention;

[0025] Figure 2 This is a block diagram illustrating the function of the protection switch assembly in Embodiment 1 of the present invention.

[0026] Figure 3 This is a circuit diagram of the positive high voltage protection switch unit in Embodiment 1 of the present invention;

[0027] Figure 4 The control principle diagrams of the detection control module in Embodiments 1 and 2 of the present invention are shown.

[0028] Figure 5 This is a system structure block diagram of the protection switch assembly in Embodiment 2 of the present invention;

[0029] Figure 6 This is a block diagram illustrating the function of the protection switch assembly in Embodiment 2 of the present invention.

[0030] Figure 7 This is a circuit diagram of the positive high voltage one-to-two isolation unit in Embodiment 2 of the present invention;

[0031] Figure 8 This is a circuit diagram of the negative high voltage one-to-two isolation unit in Embodiment 2 of the present invention;

[0032] Figure 9 This is a schematic diagram of the external structure of the protection switch assembly in Embodiment 2 of the present invention;

[0033] Figure 10 This is a physical diagram of the protection switch assembly in Embodiment 2 of the present invention.

[0034] In the picture:

[0035] 1. Charger;

[0036] 2. Protective switch assembly;

[0037] 20. Detection and control module;

[0038] 201. Fault detection module; 202. Control module;

[0039] 211. Positive high voltage protection switch unit; 212. Negative high voltage protection switch unit;

[0040] 221. One-to-two switch unit; 222. Oil-immersed high-voltage relay; 2211. Positive high-voltage one-to-two isolation unit; 2212. Negative high-voltage one-to-two isolation unit;

[0041] 3. Subsequent load balancing module;

[0042] 4. Host computer. Detailed Implementation

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] High-voltage switchgear is one of the key pieces of equipment in a power system, mainly used for functions such as power transmission and distribution interruption, isolation, transformation, and protection. With the further development and expansion of power systems, the application prospects of high-voltage switchgear will become increasingly broad.

[0045] Firstly, high-voltage switchgear plays a crucial role in urban construction. With rapid urbanization and industrialization, cities are expanding, leading to increased electricity demand. As a key device for urban power supply, high-voltage switchgear provides reliable power supply, protection, and control. Therefore, the application prospects of high-voltage switchgear in urban power supply will see exponential growth.

[0046] Secondly, high-voltage switchgear also plays a crucial role in industrial parks and large factories. Industrial production is a central theme of modern industry, resulting in relatively high electricity consumption in industrial parks and large factories. This necessitates the use of more advanced and intelligent high-voltage switchgear in power transmission and distribution to ensure the operation and safety of electrical equipment.

[0047] Furthermore, the application of high-voltage switchgear in new energy power generation systems is increasing. With rising environmental awareness and the gradual popularization of renewable energy, the scale of new energy power generation systems is continuously expanding. The electricity generated by these new energy power generation devices requires transmission, distribution, transformation, and protection, and high-voltage switchgear, as a core component of the transmission and distribution system, will play an increasingly important role in new energy power generation systems.

[0048] In conclusion, high-voltage switchgear, as a core device in power systems, has broad prospects and applications in future power system construction. It will not only help cities ensure a reliable power supply, but also play a crucial role in industrial development and new energy power generation systems.

[0049] Currently, the most commonly used switch boxes are oil-immersed, which have the following disadvantages during use:

[0050] 1. A dual-loop detection system using voltage and current is adopted. However, because the current Hall effect sensor requires a very small current (8mA), sampling of the current Hall effect sensor becomes difficult (the minimum current Hall effect sensor is 200mA). Therefore, the comparison threshold has to be increased to avoid false alarms. As a result, current sampling becomes virtually ineffective.

[0051] 2. The voltage is divided by a voltage divider. Although it can sample flashover conditions, it is also easily affected by interference from adjacent circuits, which may cause other unrelated circuits to trip when a fault is detected on one circuit.

[0052] 3. The control circuit has significant problems. In the field, one of the circuits may become uncontrollable, and the host computer's control relay will not operate. The problem can only be solved by replacing the branch detection board or the optocoupler on the main control board.

[0053] 4. The machine may crash due to excessive interference when the load is discharging. Specifically, some of the indicator lights on the host computer that show the number of switch boxes will turn off.

[0054] 5. High-voltage connectors are often inserted from top to bottom, making many high-voltage wires difficult to remove later (mainly for high-voltage wires using silicone rubber). The reason may be:

[0055] 1. When the high-voltage wire is inserted into the tube, it creates a vacuum inside the tube, making it impossible to pull out due to pressure.

[0056] 2. Due to transformer oil leakage into the aviation connectors, some of the wires swelled up, and the sealing of some aviation connectors was not done well at the time.

[0057] To address the technical problems existing in the switch boxes of the prior art, this application describes the specific implementation of the overall technical solution through the following embodiments one and two, as follows:

[0058] Example 1

[0059] Please refer to Figures 1-4 This illustration shows a specific implementation of the present embodiment. The switch box provided in this embodiment will not misjudge or miss a flashover fault. The flashover fault is detected by simultaneously detecting the charging voltage and charging current, which is equivalent to using double protection. Therefore, there will be no misjudge or miss a flashover fault. At the same time, all input and output signals are converted into optical signals for transmission. Including the charging voltage signal, which is converted into an optical signal through V / F conversion, the anti-interference ability of the signal is enhanced, thereby enhancing the reliability of the switch box.

[0060] A high-voltage one-to-two protection switch assembly system includes a charger 1 serving as a high-voltage charging power supply and a downstream load module 3 composed of multiple positive and negative high-voltage capacitors. The output terminal of the charger 1 is connected to the input terminal of the protection switch assembly 2. The protection switch assembly 2 connects the charger 1 and the downstream load module 3, connects the downstream load module 3 during charging, disconnects the downstream load module 3 during discharging, and monitors the voltage parameters of the downstream load module 3 in real time to identify fault states. A host computer 4 establishes communication with the protection switch assembly 2 through a serial port server and is used to display the voltage, current, and flashover fault status of the protection switch assembly 2.

[0061] The protection switch assembly 2 includes a total of ten positive high voltage protection switch units 211 and negative high voltage protection switch units 212, as well as a detection and control module 20 for controlling the corresponding on / off states of the positive high voltage protection switch units 211 and negative high voltage protection switch units 212 according to their voltage, current and flashover fault status. The detection and control module 20 communicates with the host computer 4 via optical fiber using the RS232 protocol and is used to receive and send control commands and status parameters of the protection switch assembly 2. When a fault occurs in some positive high voltage capacitors, the detection and control module 20 disconnects the corresponding negative high voltage capacitors to achieve a balance between positive and negative loads, and vice versa.

[0062] The detection and control module 20 includes a fault detection module 201 and a control module 202 that establish a communication connection with each other. The control module is used to receive fault signals detected by the fault detection module 201 for each protection switch component 2 and make control decisions. The fault detection module 201 includes a relay control circuit and a fault judgment and V / F conversion circuit.

[0063] Since the protection switch assembly 2 operates in a strong electromagnetic environment, in order to ensure the reliability of the system, the principle block diagram of the proposed detection and control system is as follows: Figure 4 As shown.

[0064] like Figure 4 As shown, each protection switch assembly 2 is equipped with a detection and control module 20. The fault detection module includes two parts: a relay control circuit and a fault judgment and V / F conversion circuit. The fault judgment and V / F conversion circuit is used to detect parameters such as charging voltage and charging current, and to judge the flashover fault of the load through the onboard hardware circuit. The fault status P and voltage signal Vf are transmitted to the relay control circuit through optical fiber.

[0065] When there is no fault, the fault diagnosis and V / F conversion circuit transmits the relay control signal Kc received from the relay control circuit to the relay control board, which then controls the on / off state of the relay. The relay control board also receives the relay's auxiliary contact signal Ko to determine the relay's status and transmits this status to the control circuit via optical fiber.

[0066] The control module controls 10 positive and 10 negative high-voltage protection switches. The control module receives fault signals from each protection switch component and makes control decisions, namely: when a few positive high-voltage protection switch units fail, which negative high-voltage protection switch units need to be disconnected to achieve load balance, and at the same time, transmits status information to the host computer.

[0067] The detection and control module proposed in this embodiment has the following characteristics:

[0068] 1. The signal has strong anti-interference capabilities;

[0069] All input and output signals are converted into optical signals for transmission. Even the charging voltage signal is converted into an optical signal through V / F conversion, which enhances the signal's anti-interference capability.

[0070] 2. High isolation voltage output;

[0071] The circuit board is powered entirely by a transformer with a high isolation voltage level, ensuring high isolation. It also uses a linear power supply, resulting in high power supply reliability.

[0072] 3. The operating status of the high-voltage switch can be reliably obtained;

[0073] A high-voltage single-pole double-throw switch with auxiliary contacts is used, which can reliably obtain the operating status of the high-voltage switch.

[0074] 4. Hardware detection of flashover faults to improve response speed to fault conditions;

[0075] The fault detection module is built with pure hardware electronic components and does not require MCU software control, so the response speed is much faster.

[0076] 5. Flashover faults will not be misdiagnosed or missed;

[0077] When a downstream load flashes over, the load voltage drops suddenly, causing other loads to draw current to the flashed load, resulting in a sudden increase in charging current. Taking advantage of these two characteristics, flashover fault detection uses the method of simultaneously detecting charging voltage and charging current to determine the fault, which is equivalent to using double insurance. Therefore, flashover faults will not be misjudged or missed, thus enhancing the reliability of the system.

[0078] The protection switch assembly provided in this embodiment is oil-immersed, and all power devices have been epoxy potted. Each of the 10 switch boxes can withstand a voltage of 120kV / min. The oil tank weighs 3T after being filled with oil, and the oil weighs 2T.

[0079] Positive high-voltage protection switch unit 211 and negative high-voltage protection switch unit 212 are electrically connected to charger 1 via positive and negative high-voltage charging lines, respectively. Positive high-voltage protection switch unit 211 and negative high-voltage protection switch unit 212 are used to respectively switch on and off the corresponding ten positive and negative high-voltage capacitors. Positive high-voltage protection switch unit 211 can be implemented using a conventional positive high-voltage protection switch box. The circuit principle is as follows: Figure 3 As shown, the circuit principle of the corresponding negative high voltage protection switch unit 212 is the same, except that the direction of the isolation diode for reverse voltage protection is changed, and everything else is the same.

[0080] In this embodiment, as Figure 1As shown, the protection switch assembly 2 is divided into a positive high-voltage protection switch unit 211 and a negative high-voltage protection switch unit 212. These units charge the subsequent positive and negative high-voltage capacitors via the positive and negative high-voltage charging lines of the charger 1, respectively. Each protection switch assembly 2 contains 10 positive high-voltage protection switch units 211 and 10 negative high-voltage protection switch units 212, which respectively switch on and off the corresponding 10 positive and negative high-voltage capacitors. Each group of 10 positive and 10 negative high-voltage protection switch units forms a set, controlled by the detection and control module 20. When a fault occurs in some positive high-voltage capacitors, the detection and control module 20 disconnects the corresponding negative high-voltage capacitors to balance the positive and negative loads, and vice versa. Furthermore, the detection and control module 20 communicates with the host computer via optical fiber using the RS232 protocol, receiving and sending control commands and status parameters of the positive and negative high-voltage protection switch units 211 and 212. The detection and control modules 20 are interconnected with the charger to form a serial server network, facilitating system expansion. The system status is displayed on the host computer.

[0081] like Figure 2 As shown, the detection and control module 20 simultaneously controls the connection, disconnection, and energy discharge of 10 positive high-voltage protection switch units 211 and 10 negative high-voltage protection switch units 212. At the same time, it detects the voltage, current, and flashover fault status of each protection switch assembly 2. All parameters are uploaded to the host computer 4 for display via fiber optic communication. When several protection switch assemblies 2 are disconnected due to flashover faults, the system can simultaneously disconnect the corresponding protection switch assemblies 2 with opposite polarities to achieve load balance between the positive high-voltage protection switch units 211 and the negative high-voltage protection switch units 212 by judging and disconnecting them at the same time.

[0082] In this embodiment, the protection switch assembly 2 is used to connect the charger 1 and the downstream load module 3. It connects the downstream load module 3 during charging and disconnects it during discharging. Furthermore, it can detect voltage parameters and identify fault states in real time. The technical specifications achievable through verification of the protection switch assembly 2 are as follows:

[0083] 1. Isolation voltage level is ±100kV (withstand voltage reaches ±120kV);

[0084] 2. It has load voltage detection and flashover fault detection functions;

[0085] 3. It can transmit data such as switch status, flashover status, and load voltage to the host computer;

[0086] 4. It can realize functions such as on / off control, energy discharge, flashover disconnection and voltage maintenance through the host computer;

[0087] During the charging process, the load flashover fault detection must not miss or misjudge, and it can quickly disconnect (the command issuance time does not exceed 5ms);

[0088] 5. Positive and negative polarity protection switches for the same load can be linked, while protection switches for different loads do not affect each other.

[0089] 6. The voltage measurement accuracy of the protection switch assembly is better than 0.5%.

[0090] Example 2

[0091] This embodiment focuses on describing the differences from other embodiments. For parts that are the same as or similar to Embodiment 1, please refer to the relevant sections of Embodiment 1. Regarding Embodiment 1, since this embodiment is based on Embodiment 1, the similarities will not be described again; for related parts, please refer to the relevant sections of Embodiment 1.

[0092] Please refer to Figures 4-10 This illustration shows a specific implementation of the present embodiment. The switch box proposed in this embodiment has load voltage detection and flashover fault detection functions. It can transmit data such as switch status, flashover status and load voltage to the host computer. The host computer can realize functions such as on / off control, energy leakage, flashover disconnection and voltage maintenance. During the charging process, the load flashover fault detection will not have missed detection or false detection, and can quickly achieve disconnection. Therefore, the positive and negative polarity protection switches of the same load can be linked, and the operation of protection switches of different loads does not affect each other. Moreover, one protection switch component can simultaneously isolate and protect two loads.

[0093] like Figure 5 As shown, the protection switch assembly 2 also includes a total of five sets of one-to-two switch units 221, and an oil-immersed high-voltage relay 222 electrically connected to the one-to-two switch units 221. Each set of one-to-two switch units 221 includes a positive high-voltage one-to-two isolation unit 2211 and a negative high-voltage one-to-two isolation unit 2212.

[0094] The protection switch assembly 2 also includes a detection and control module 20 for controlling the corresponding on / off states of the positive high voltage one-to-two isolation unit 2211 and the negative high voltage one-to-two isolation unit 2212 based on their voltage, current and flashover fault status. When a few positive high voltage capacitors fail, the detection and control module 20 disconnects the corresponding negative high voltage capacitors to achieve a balance between positive and negative loads, and vice versa.

[0095] Two oil-immersed high-voltage relays 222 are electrically connected to the charger 1 via positive and negative high-voltage charging lines, respectively. The positive high-voltage one-to-two isolation unit 2211 and the negative high-voltage one-to-two isolation unit 2212 are used to switch on and off the two corresponding positive high-voltage capacitors and negative high-voltage capacitors, respectively.

[0096] like Figure 5 As shown, the protection switch assembly 2 includes 5 sets of one-to-two switch units 221. Each set of one-to-two switch units 221 is divided into a positive high-voltage one-to-two isolation unit 2211 and a negative high-voltage one-to-two isolation unit 2212. They charge the positive and negative high-voltage capacitors of the downstream stage through the positive high-voltage charging line and the negative high-voltage charging line of the charger 1, respectively. Each set of one-to-two switch units 221 switches on and off the corresponding 10 capacitors. The positive high-voltage one-to-two isolation unit 2211 and the negative high-voltage one-to-two isolation unit 2212 form a group and are controlled by the detection and control module 20. When a few positive high-voltage capacitors fail, the detection and control module 20 disconnects the corresponding few negative high-voltage capacitors to achieve the balance of positive and negative loads, and vice versa. The detection and control module 20 communicates with the host computer 4 via optical fiber using the RS232 protocol, receiving and sending control commands and status parameters for the positive high-voltage one-to-two isolation unit 2211 and the negative high-voltage one-to-two isolation unit 2212. The detection and control modules 20 are interconnected with the charger 1 to form a serial port server network, facilitating system expansion. The system status is displayed on the host computer 4. The implementation block diagram for this function is shown below. Figure 6 As shown.

[0097] exist Figure 6 In this system, the detection and control module 20 simultaneously controls the connection, disconnection, and energy discharge of 5 positive high-voltage one-to-two isolation units 2211 and 5 negative high-voltage one-to-two isolation units 2212. At the same time, it detects the voltage, current, and flashover fault status of each pair of protection switch components 2. All parameters are uploaded to the host computer 4 for display via fiber optic communication. When some protection switch components 2 are disconnected due to flashover fault, the system can simultaneously disconnect the corresponding protection switch components 2 with opposite polarities to achieve load balance between the positive high-voltage one-to-two isolation units 2211 and the negative high-voltage one-to-two isolation units 2212.

[0098] The positive high voltage one-to-two isolation unit 2211 includes a leakage protection resistor and a Hall current sensor connected in sequence to the output terminal of the oil-immersed high voltage relay 222. An isolation diode is connected in parallel across the two ends of the leakage protection resistor to prevent reverse voltage during charging and discharging. An anti-series diode and a voltage divider are connected in parallel between the leakage protection resistor and the Hall current sensor to detect the charging voltage and charging current in real time, and the other end of the voltage divider is grounded.

[0099] like Figure 7The diagram shown is a circuit diagram of the positive high voltage one-to-two isolation unit in this embodiment. The single-pole double-throw disconnect switch is in the energy dissipation state when static and in the charging state when energized. The isolation diode is used to prevent reverse voltage during the charging and discharging process, and the protection resistor is used to protect the isolation diode. During operation, the positive high voltage one-to-two isolation unit 2211 detects the charging voltage and charging current in real time through the voltage divider and Hall current sensor, and detects voltage flashover faults through the charging voltage and charging current. When a fault occurs, the charging circuit is automatically disconnected.

[0100] like Figure 8 The diagram shown is the circuit schematic of the negative high voltage one-to-two isolation unit in this embodiment. It is basically the same in principle as the positive high voltage one-to-two isolation unit in the circuit schematic of the protection switch assembly. The only difference is that the direction of the isolation diode when preventing reverse voltage is changed. The rest are the same and will not be described in detail here.

[0101] The oil-immersed high-voltage relay 222 includes a single-pole double-throw disconnector, in which one of the contacts is grounded through a grounding resistor.

[0102] The detection and control module 20 communicates with the host computer 4 via optical fiber using the RS232 protocol, and is used to receive and send control commands and status parameters of the protection switch assembly 2.

[0103] The detection and control module 20 includes a fault detection module 201 and a control module 202 that establish a communication connection with each other. The control module 202 is used to receive the fault signals detected by the fault detection module 201 for each protection switch component 2 and make control decisions. The fault detection module 201 includes a relay control circuit and a fault judgment and V / F conversion circuit.

[0104] Since the protective switch assembly operates in a strong electromagnetic environment, in order to ensure the reliability of the system, the following measures are proposed: Figure 4 The control principle diagram of the detection control module controlling the protection switch assembly is shown. Each protection switch assembly is equipped with a corresponding detection control module 20. In the detection control module 20, the fault detection module includes two parts: a relay control circuit and a fault judgment and V / F conversion circuit. The fault judgment and V / F conversion circuit is used to detect parameters such as charging voltage and charging current, and to judge the flashover fault of the load through the onboard hardware circuit. The flashover fault status P and voltage signal Vf are transmitted to the relay control circuit through optical fiber.

[0105] When there is no fault, the fault diagnosis and V / F conversion circuit transmits the relay control signal Kc received from the relay control module to the relay control board, which then controls the on / off state of the relay. The relay control board also receives the relay's auxiliary contact signal Ko to determine the relay's status and transmits this status to the control module via optical fiber.

[0106] The control module controls the five positive and five negative protection switch assemblies. The control module receives fault signals from each protection switch assembly and makes control decisions, namely: when a fault occurs in a few positive high voltage 1-to-2 isolation units, it determines which negative high voltage 1-to-2 isolation units need to be disconnected to achieve load balance, and at the same time transmits status information to the host computer.

[0107] The detection and control module proposed in this embodiment has the following characteristics:

[0108] 1. The signal has strong anti-interference capabilities;

[0109] All input and output signals are converted into optical signals for transmission. Even the charging voltage signal is converted into an optical signal through V / F conversion, which enhances the signal's anti-interference capability.

[0110] 2. High isolation voltage output;

[0111] The circuit board is powered entirely by a transformer with a high isolation voltage level, ensuring high isolation. It also uses a linear power supply, resulting in high power supply reliability.

[0112] 3. The operating status of the protection switch assembly can be reliably obtained;

[0113] A high-voltage single-pole double-throw disconnector with auxiliary contacts is used, which can reliably obtain the operating status of the protection switch components.

[0114] 4. Hardware detection of flashover faults to improve response speed to fault conditions;

[0115] The fault detection module is built using pure hardware electronic components and does not require MCU software control, thus its response speed is much faster.

[0116] 5. Flashover faults will not be misdiagnosed or missed;

[0117] When a downstream load flashes over, the load voltage drops suddenly, causing other loads to draw current to the flashed load, resulting in a sudden increase in charging current. Taking advantage of these two characteristics, flashover fault detection uses the method of simultaneously detecting charging voltage and charging current to determine the fault, which is equivalent to using double insurance. Therefore, flashover faults will not be misjudged or missed, thus enhancing the reliability of the system.

[0118] In this embodiment, the protection switch assembly 2 is used to connect the charger 1 and the downstream load module 3. It connects the downstream load module 3 during charging and disconnects it during discharging. Furthermore, it can detect voltage parameters and identify fault states in real time. The technical specifications achievable through verification of the protection switch assembly 2 are as follows:

[0119] 1. The isolation voltage level is positive or negative 120kV;

[0120] 2. It has load voltage detection and flashover fault detection functions;

[0121] 3. It can transmit data such as switch status, flashover status, and load voltage to the host computer;

[0122] 4. It can realize functions such as on / off control, energy discharge, flashover disconnection and voltage maintenance through the host computer;

[0123] 5. During the charging process, the load flashover fault detection must not miss or misjudge, and it must be able to quickly disconnect (the command issuance time does not exceed 5ms);

[0124] 6. Positive and negative polarity protection switches for the same load can be linked, while protection switches for different loads do not affect each other.

[0125] 7. The voltage measurement accuracy of the protection switch assembly is better than 0.5%;

[0126] 8. A single switch assembly can simultaneously isolate and protect two loads.

[0127] The protective switch assembly provided in this embodiment, namely the high-voltage switch box, adopts a dry potting method, the high-voltage relay is oil-immersed, it uses multi-channel aviation plug output, and is insulated and potted. It is small in size and light in weight, with a final weight of 0.4T, and has the following advantages:

[0128] 1) During use, the relay did not exhibit any phenomena such as spring, armature, or contact jamming.

[0129] 2) The main control board was not damaged during the discharge process.

[0130] 3) Small size, light weight, and easy on-site installation.

[0131] 4) The dry-type scheme eliminates the need to change the transformer oil.

[0132] 5) The dry-type solution solved the problem of inconvenient plugging and unplugging of high-voltage lines.

[0133] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0134] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-voltage one-to-two protection switch assembly system, comprising a charger (1) as a high-voltage charging power supply, and a downstream load module (3) composed of multiple positive high-voltage capacitors and negative high-voltage capacitors, characterized in that, include: The output terminal of the charger (1) is connected to the input terminal of the protection switch assembly (2). The protection switch assembly (2) is used to connect the charger (1) and the downstream load module (3). It connects the downstream load module (3) during charging and disconnects the downstream load module (3) during discharging. It also detects the voltage parameters of the downstream load module (3) in real time and identifies the fault status. The protection switch assembly (2) also includes a total of five sets of one-to-two switch units (221), and an oil-immersed high-voltage relay (222) electrically connected to the one-to-two switch unit (221). Each set of one-to-two switch units (221) includes a positive high-voltage one-to-two isolation unit (2211) and a negative high-voltage one-to-two isolation unit (2212). The two oil-immersed high-voltage relays (222) are electrically connected to the charger (1) via positive and negative high-voltage charging lines, respectively. The positive high-voltage one-to-two isolation unit (2211) and the negative high-voltage one-to-two isolation unit (2212) are used to switch on and off the two corresponding positive high-voltage capacitors and negative high-voltage capacitors, respectively. The positive high voltage one-to-two isolation unit (2211) includes a leakage protection resistor and a Hall current sensor connected in sequence to the output terminal of the oil-immersed high voltage relay (222). An isolation diode is connected in parallel across the two ends of the leakage protection resistor to prevent reverse voltage during charging and discharging. An anti-series diode and a voltage divider are connected in parallel between the leakage protection resistor and the Hall current sensor to detect the charging voltage and charging current in real time, and the other end of the voltage divider is grounded. The host computer (4) establishes communication with the protection switch assembly (2) through the serial port server and is used to display the voltage, current and flashover fault status of the protection switch assembly (2).

2. The high-voltage one-to-two protection switch assembly system according to claim 1, characterized in that, The protection switch assembly (2) includes a total of ten positive high voltage protection switch units (211) and negative high voltage protection switch units (212), as well as a detection and control module (20) for controlling the corresponding on / off states of the positive high voltage protection switch units (211) and negative high voltage protection switch units (212) according to their voltage, current and flashover fault status.

3. The high-voltage one-to-two protection switch assembly system according to claim 2, characterized in that, The positive high voltage protection switch unit (211) and the negative high voltage protection switch unit (212) are electrically connected to the charger (1) through positive and negative high voltage charging lines, respectively. The positive high voltage protection switch unit (211) and the negative high voltage protection switch unit (212) are used to switch on and off the corresponding ten positive high voltage capacitors and negative high voltage capacitors, respectively.

4. The high-voltage one-to-two protection switch assembly system according to claim 2 or 3, characterized in that, The detection control module (20) communicates with the host computer (4) via optical fiber using the RS232 protocol, and is used to receive and send control commands and status parameters of the protection switch assembly (2).

5. The high-voltage one-to-two protection switch assembly system according to claim 1, characterized in that, The protection switch assembly (2) further includes a detection and control module (20) for controlling the corresponding on / off states of the positive high voltage one-to-two isolation unit (2211) and the negative high voltage one-to-two isolation unit (2212) based on their voltage, current and flashover fault status.

6. The high-voltage one-to-two protection switch assembly system according to claim 1, characterized in that, The oil-immersed high-voltage relay (222) includes a single-pole double-throw disconnector, with one of its contacts grounded through a grounding resistor.

7. The high-voltage one-to-two protection switch assembly system according to claim 2, characterized in that, The detection and control module (20) includes a fault detection module (201) and a control module (202) that establish a communication connection with each other. The control module (202) is used to receive the fault signals of each protection switch assembly (2) detected by the fault detection module (201) and make control decisions. The fault detection module (201) includes a relay control circuit and a fault judgment and V / F conversion circuit.

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