Sequential control system and device of hybrid solid-state direct-current circuit breaker and circuit breaker

Abstract

The invention discloses a sequential control system and device of a hybrid solid-state direct-current circuit breaker and the circuit breaker, and belongs to the technical field of circuit breakers. The sequential control system comprises an energy taking unit, a pulse unit, a voltage reduction unit and a control unit; the energy taking unit is used for being conducted with a direct current system to store energy at a first position in the closing process of the circuit breaker; the voltage reduction unit is used for reducing the voltage of the energy taking unit and then having functions on the pulse unit and the control unit; the pulse unit is used for sending a pulse signal at a second position in the closing process of the circuit breaker, and the circuit breaker sequentially passes through the first position and the second position in the closing process; the control unit is used for sending a control signal according to a pulse signal of the pulse unit, so that an electronic branch of the circuit breaker is firstly conducted; according to the system, the mechanical branch and the electronic branch of the circuit breaker are controlled, and the system works according to the specified sequence of the hybrid solid-state circuit breaker, so that the working reliability of the hybrid circuit breaker is improved, and the safety of a direct-current system is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit breakers, and in particular to a timing control system, a device and a circuit breaker of a hybrid solid-state DC circuit breaker. Background Art

[0002] Existing low-voltage circuit breaker products, when used in DC systems, often require multi-pole series connection or amplified arc extinguishing systems to achieve product performance. Product performance requirements are getting higher and higher, and traditional products can no longer meet higher performance requirements. At present, more and more low-voltage electrical appliance manufacturers are researching solid-state circuit breakers, and some pure solid-state circuit breaker products have appeared. However, due to the high cost, they are not widely used. Mainly because of the big problem of heat dissipation, cooling devices are still needed, so only some small current products (below 80A) can be put into formal application. As a result, hybrid solid-state circuit breakers that combine the advantages of traditional mechanical circuit breakers and solid-state circuit breakers have emerged.

[0003] Hybrid solid-state circuit breakers can intervene when the mechanical circuit breaker is opened through electronic components. During the opening process, the mechanical contacts are disconnected, and then the power electronic device IGBT is turned on. Under the action of arc voltage, the current is commutated to the power electronic device, and the arc between the contacts is quickly extinguished. After the power electronic device is turned off, the current is commutated to the energy-consuming branch MOV to complete the fault current clearing. However, there is less discussion about the closing process. During the closing process, as the contact spacing decreases, arcs will also be generated, exacerbating contact erosion, thereby reducing electrical life.

[0004] In order to solve the problem of reduced electrical life caused by arc burning, it is necessary to first turn on the power electronic devices during the closing process, so that the mechanical contacts are closed under zero current and voltage conditions. At the same time, the current transfer should be completed as soon as possible during the opening process to reduce the arcing time. Therefore, a timing control structure is required to control the mechanical branch and electronic branch of the circuit breaker to work in the specified sequence of the hybrid solid-state circuit breaker to improve the working reliability of the hybrid circuit breaker and ensure the safety of the DC system. Summary of the invention

[0005] In view of the problems existing in the prior art, the present invention provides a timing control system, device and circuit breaker of a hybrid solid-state DC circuit breaker, which controls the mechanical branch and electronic branch of the circuit breaker and operates in a specified sequence of the hybrid solid-state circuit breaker to improve the working reliability of the hybrid circuit breaker and ensure the safety of the DC system.

[0006] The present invention is achieved through the following technical solutions: In a first aspect, the present application provides a timing control system for a hybrid solid-state DC circuit breaker, including an energy taking unit, a pulse unit, a voltage reducing unit and a control unit; An energy taking unit is used to conduct with the DC system to store energy in the first position of the circuit breaker closing process; The step-down unit is used to step down the voltage of the energy taking unit and then control the functions of the pulse unit and the control unit; A pulse unit, used to send a pulse signal at a second position during the closing process of the circuit breaker, and the circuit breaker passes through the first position and the second position in sequence during the closing process; The control unit is used to send a control signal according to the pulse signal of the pulse unit so that the electronic branch of the circuit breaker is turned on first.

[0007] Furthermore, the energy acquisition unit is connected to the positive electrode A of the DC system and the load B respectively, and the energy acquisition unit is connected to the positive electrode A of the DC system through an auxiliary switch Q2, and the auxiliary switch Q2 is located in the first position.

[0008] Furthermore, the energy acquisition unit is connected to the pulse unit via a dip switch Q1, and the dip switch Q1 is set in the second position.

[0009] Furthermore, the energy acquisition unit is connected to the control unit via a conditioning unit; The conditioning unit detects the voltage of the energy storage unit and sends a voltage signal to the control unit. When the voltage reaches a threshold, the control unit sends a control signal.

[0010] Furthermore, the control unit is connected to the electronic branch of the circuit breaker via a driving unit, and the driving unit controls the conduction state of the IGBT of the electronic branch.

[0011] In a second aspect, the present application provides a timing control device for a hybrid solid-state DC circuit breaker, characterized in that it comprises a push rod, and a timing control system according to any one of claims 1 to 6; The push rod is connected to the operating mechanism of the circuit breaker and rotates synchronously. During the closing process, the push rod passes through the first position and the second position of the circuit breaker in sequence, and the timing control system is connected to the electronic branch of the circuit breaker.

[0012] Furthermore, a DIP switch Q1 and an auxiliary switch Q2 are respectively installed on the circuit breaker; The auxiliary switch Q2 is installed at the first position of the circuit breaker, and the dial switch Q1 is installed at the second position of the circuit breaker.

[0013] In a third aspect, the present application provides a hybrid solid-state DC circuit breaker, characterized in that it includes the timing control system.

[0014] In a fourth aspect, the present application provides a high-voltage electrical equipment, including the hybrid solid-state DC circuit breaker.

[0015] Compared with the prior art, the present invention has the following beneficial technical effects: The present invention provides a timing control system. During the closing process of the circuit breaker, the energy taking unit is first connected to the DC system to store energy and perform functions for each unit. During the continued closing process, the pulse unit is triggered to send a pulse signal to the control unit. The control unit sends a control signal according to the voltage and pulse signal of the energy taking unit to turn on the IGBT of the electronic branch of the circuit breaker. At this time, no current passes through the mechanical switch. When the mechanical switch is closed, the current is commutated to the mechanical switch, so that the mechanical contact is closed under zero current and voltage conditions, thereby solving the problem of arc burning of the moving and static contacts of the mechanical switch during the closing process, and the problem of reduced electrical appliance life caused by arc burning. The system controls the mechanical branch and the electronic branch of the circuit breaker and works in the specified order of the hybrid solid-state circuit breaker to improve the working reliability of the hybrid circuit breaker and ensure the safety of the DC system.

[0016] The present application also proposes a timing control device, a hybrid solid-state DC circuit breaker and a high-voltage electrical equipment, which have all the advantages of the above-mentioned timing control system. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 is a structural diagram of the timing control device of the present invention; Figure 2 is a schematic diagram of the timing control device of the present invention; Figure 3 It is a structural schematic diagram of the circuit breaker of the present invention; Figure 4 It is a structural diagram of the DIP switch of the present invention; Figure 5 It is a structural diagram of each state of the auxiliary switch of the present invention; Figure 6 is a structural diagram of the circuit breaker operating mechanism of the present invention; Figure 7 It is a structural diagram of the push rod and the auxiliary switch of the present invention; Figure 8 It is a structural diagram of the push rod and the DIP switch of the present invention; Fig. 9 It is a structural diagram of the circuit breaker in the open state of the present invention; Fig.10 It is a structural diagram of the hybrid solid-state DC circuit breaker of the present invention.

[0019] In the figure: 1, push rod; 2, rotating shaft; Q1, dip switch; Q2, auxiliary switch; K, mechanical switch; K1, moving contact; K2, static contact; M, hybrid solid-state DC molded case circuit breaker; E, timing control system. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0021] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0022] The molded case circuit breaker includes a cover, a base, an operating mechanism, an arc extinguishing unit box and a release; three contact arc extinguishing unit boxes are placed side by side and installed in the base, the three contact arc extinguishing unit boxes are connected to the operating mechanism, and the three contact arc extinguishing unit boxes are controlled by the operating mechanism to perform opening and closing actions, the release is connected to the contact arc extinguishing unit box and is located at the bottom, and the cover is set on the top of the base to form an integral structure.

[0023] When the circuit needs to be disconnected, the operating mechanism receives the opening command. The opening iron core inside the operating mechanism moves after receiving the command, and the rotating shaft of the operating mechanism moves to separate the contact from the static contact, thereby disconnecting the circuit. During the contact separation process, the arc extinguishing medium (such as air, inert gas or oil, etc.) in the arc extinguishing unit box begins to work and extinguishes the possible arc. At the same time, the oil-separating damper at the end of the conductive rod starts to work, slowing down the speed of the conductive rod and ensuring smooth separation of the contacts. After the contact separation, the releaser acts to ensure that the circuit breaker remains in the open state.

[0024] When the circuit needs to be closed, the operating mechanism receives a closing command, and the operating mechanism's rotating shaft moves, causing the contacts to come into close contact with the stationary contacts, thereby closing the circuit.

[0025] See also Figure 1-10 , a timing control system of a hybrid solid-state DC circuit breaker, comprising an energy taking unit, a pulse unit, a conditioning circuit, a control unit, a driving unit and a voltage reducing unit; The energy taking unit is used to conduct with the DC system to store energy during the closing process of the circuit breaker; A pulse unit, used to send a pulse signal during the closing process of the circuit breaker; A conditioning unit, used for detecting the voltage of the energy storage unit; The step-down unit is used to control the functions of the pulse unit, the control unit and the drive unit through the energy taking unit; The control unit is used to send a control signal according to the pulse signal of the pulse unit and in combination with the voltage signal of the energy taking unit sent by the conditioning unit, so that the electronic branch of the circuit breaker is turned on first.

[0026] In the timing control system, during the closing process of the circuit breaker, the energy taking unit is first connected to the DC system to store energy and perform functions for each unit. During the continued closing process, the pulse unit is triggered to send a pulse signal to the control unit. The control unit sends a control signal according to the voltage and pulse signal of the energy taking unit, so that the IGBT of the electronic branch of the circuit breaker is turned on, and no current passes through the mechanical switch. When the mechanical switch is closed, the current is commutated to the mechanical switch, so that the mechanical contacts are closed under zero current and voltage conditions, thereby solving the problem of arc burning the moving and static contacts during the closing process of the mechanical switch, and the problem of reduced electrical appliance life caused by arc burning.

[0027] During the opening process, the mechanical switch is disconnected, the IGBT of the power branch is turned on, and under the action of arc voltage, the current is commutated to the power electronic device, the arc between the contacts is quickly extinguished, and after the power electronic device is turned off, the current is commutated to the energy consumption branch MOV, completing the fault current clearing.

[0028] In some embodiments, the energy acquisition unit is connected to the positive electrode A of the DC system and the load B respectively, and the energy acquisition unit is charged through the voltage drop across AB.

[0029] The energy acquisition unit is connected to the positive pole A of the DC system through the DIP switch Q1. When the circuit breaker is closed, the DIP switch Q1 is triggered to close and the energy acquisition unit is charged.

[0030] In some embodiments, the energy acquisition unit is connected to the pulse unit through a dip switch Q1. The dip switch Q1 is used to detect the closing action of the circuit breaker. The circuit breaker triggers the dip switch Q1 during the closing process, and the pulse unit sends a pulse signal, indicating that the circuit breaker is closing. It should be noted that the dip switch Q1 is not triggered during the opening process of the circuit breaker.

[0031] In some embodiments, the conditioning circuit is used to detect the voltage of the energy storage unit and send it to the control unit. The control unit determines whether the voltage of the energy acquisition unit reaches a threshold value, and sends a control signal in combination with a pulse signal when the threshold value is reached. When the voltage does not reach the threshold value, it means that the voltage of the energy acquisition unit does not reach the normal operating voltage of the driving chip and cannot drive the electronic branch.

[0032] In some embodiments, the control unit uses a single-chip microcomputer, which sends a control signal to the drive unit, and the drive unit drives the IGBT to turn on and provide a drive voltage signal; In some embodiments, the step-down unit includes a DC / DC converter M1 and a DC / DC converter M2, and the energy taking unit is connected to the control unit and the driving unit through the two converters.

[0033] Two DC / DC converters are used to convert the energy-harvesting circuit voltage into voltage signals for driving IC and MCU power supply, with standard values ​​of 15V and 3.3V respectively. The pulse trigger circuit is used to provide 3.3V pulse voltage for MCU detection.

[0034] Example 1 Correspondingly, the present application also provides a timing control device for a hybrid solid-state DC circuit breaker, comprising a push rod 1, a dip switch Q1, an auxiliary switch Q2 and a timing control system E.

[0035] Push rod 1 is installed on the outer contact arc extinguishing unit box. Fig.10 The middle push rod is installed on the right side contact arc extinguishing unit box. The push rod 1 is fixedly connected to the rotating shaft of the operating structure and rotates synchronously. The switch Q1 and the switch Q2 are arranged on the circuit breaker and connected to the timing control unit. The dial switch Q1 and the auxiliary switch Q2 are located on the rotation track of the push rod 1 and are used to obtain the action state of the circuit breaker. The circuit breaker triggers the auxiliary switch Q2 and the dial switch Q1 in sequence during the closing process.

[0036] In this embodiment, the auxiliary switch Q2 is installed on the cover of the circuit breaker, and the contact of the auxiliary switch Q2 cooperates with the push rod. When the push rod is in the closing position, the contact of the auxiliary switch Q2 is triggered to the closed position, and a continuous signal of closing is transmitted through the line. When the push rod 1 is in the opening position, the auxiliary switch Q2 also goes to the separation position, and a continuous signal of opening is transmitted through the line. The code switch Q1 is installed on the contact arc extinguishing unit box, and the code of the code switch Q1 cooperates with the push rod. When the push rod changes from closing to opening or from opening to closing, the code switch will be toggled once, forming a signal, which is transmitted to the timing control unit.

[0037] The working principle of the timing control device of the hybrid solid-state DC circuit breaker is described in detail below.

[0038] The closing process of the hybrid solid-state circuit breaker is as follows: 1. When receiving the closing command, the hybrid solid-state circuit breaker closes, the operating mechanism is activated, the shaft 2 drives the push rod 1 to rotate synchronously, and the auxiliary switch Q2 is triggered during the rotation process. The DC system is connected to the energy taking unit and charged under the action of voltage.

[0039] 2. The shaft drives the push rod 1 to continue to rotate in the closing direction. The push rod triggers the dial switch Q1. The pulse unit receives the rising edge signal and sends a pulse signal. The control unit receives the pulse signal and sends a control signal to the drive unit. The drive unit turns on the IGBT S1 of the electronic branch according to the control signal, so that the DC system and the load are turned on.

[0040] 3. The shaft drives the push rod 1 to continue to rotate in the closing direction until the mechanical switch K is closed, that is, the moving contact K1 and the static contact K2 of the circuit breaker are in contact, the commutation unit of the electronic branch works to commutate, and the DC system is connected to the load through the mechanical switch K.

[0041] The opening process of the hybrid solid-state circuit breaker is as follows: 1. When receiving the opening command, the hybrid solid-state circuit breaker opens, the operating mechanism is activated, the mechanical switch K is disconnected, and an arc is generated between the moving and static contacts, and the energy taking unit is charged at the same time. The IGBT of the power branch is turned on and commutates. Under the action of arc voltage, the current is commutated to the power electronic device, the arc between the contacts is quickly extinguished, and after the power electronic device is turned off, the current is commutated to the energy consumption branch MOV, completing the fault current clearing.

[0042] 2. The shaft drives the push rod 1 to continue to rotate in the opening direction, and then triggers the DIP switch Q1 to operate. It should be noted that the DIP switch Q1 does not send a trigger signal at this time.

[0043] 3. The shaft drives the push rod 1 to continue to rotate in the opening direction, triggering the auxiliary switch Q2 to separate and disconnect the energy taking unit.

[0044] See also Figure 4 The head of the dip switch Q1 can be dialed once after the push rod passes, and then reset immediately. The reverse push will also be dialed once in the reverse direction.

[0045] See also Figure 5 The auxiliary switch can achieve several positions, open-closed-closed overtravel. The overtravel generated when closing is used to realize the timing. When the mechanical contact K just starts to close, the function of the auxiliary switch Q2 begins to be realized, but when the mechanical contact continues to move downward, the function of the dial switch Q1 continues to be realized and finally closes, the excess travel is completed by the closed overtravel.

[0046] See also Figure 7 and 8 The push rod includes a handle and a touch plate. One end of the handle is connected to the shaft of the operating structure, and the other end is connected to the touch plate. The touch plate can trigger the code switch Q1 and the auxiliary switch Q2 during rotation. When the moving contact of the mechanical switch is closed, the shaft rotates with the moving contact. The rotation of the shaft drives the push rod to move downward in coordination with the touch plates of the code switch Q1 and the auxiliary switch Q2.

[0047] Refer to 9 and 10. The touch plate of the push rod leaves the small push rod of the auxiliary contact of Q2, so that the auxiliary switch Q2 sends a signal and the energy-taking circuit in the circuit board starts to work. The touch plate of the large push rod hits the dip switch Q1, and the dip switch Q1 is toggled. Note that it does not work for a long time. The dip switch Q1 sends a signal and the IGBT is turned on. IGBT S1 performs commutation to reduce circuit damage when closing. When opening, the signal generated by the opening of the mechanical switch allows the energy-taking circuit to work and start commutation. At this time, the dip switch Q1 and the auxiliary switch Q2 do not work, but just pass by when turning back. A few milliseconds after the last contact is opened, the commutation is also completed. In this way, the product completes the commutation when breaking.

[0048] Example 2 The present application also provides a hybrid solid-state DC circuit breaker, including a hybrid solid-state DC molded case circuit breaker M and a timing control device.

[0049] Example 3 The present application also provides a high-voltage electrical equipment, including the hybrid solid-state DC circuit breaker described in Example 2.

[0050] Example 4 An electric power system comprises the high-voltage electrical equipment described in Example 3.

[0051] The power system includes substations, industrial power grids, distribution systems, high-voltage transmission grids, new energy power generation systems, etc.

[0052] The above contents are only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A timing control system for a hybrid solid-state DC circuit breaker, characterized in that: It includes an energy taking unit, a pulse unit, a voltage reducing unit and a control unit; An energy taking unit is used to conduct with the DC system to store energy in the first position of the circuit breaker closing process; The step-down unit is used to step down the voltage of the energy taking unit and then control the functions of the pulse unit and the control unit; A pulse unit, used to send a pulse signal at a second position during the closing process of the circuit breaker, and the circuit breaker passes through the first position and the second position in sequence during the closing process; The control unit is used to send a control signal according to the pulse signal of the pulse unit so that the electronic branch of the circuit breaker is turned on first.

2. The timing control system of a hybrid solid-state DC circuit breaker according to claim 1, characterized in that: The energy acquisition unit is connected to the positive electrode A of the DC system and the load B respectively. The energy acquisition unit is connected to the positive electrode A of the DC system via an auxiliary switch Q2. The auxiliary switch Q2 is located at a first position.

3. The timing control system of a hybrid solid-state DC circuit breaker according to claim 1, characterized in that: The energy taking unit is connected to the pulse unit via a dial switch Q1, and the dial switch Q1 is set in the second position.

4. The timing control system of a hybrid solid-state DC circuit breaker according to claim 1, characterized in that: The energy taking unit is connected to the control unit via the conditioning unit; The conditioning unit detects the voltage of the energy storage unit and sends a voltage signal to the control unit. When the voltage reaches a threshold, the control unit sends a control signal.

5. The timing control system of a hybrid solid-state DC circuit breaker according to claim 1, characterized in that: The voltage reduction unit uses DC / DC conversion to reduce the voltage.

6. The timing control system of a hybrid solid-state DC circuit breaker according to claim 1, characterized in that: The control unit is connected to the electronic branch of the circuit breaker via a driving unit, and the driving unit controls the conduction state of the IGBT of the electronic branch.

7. A timing control device for a hybrid solid-state DC circuit breaker, characterized in that: It comprises a push rod and a timing control system according to any one of claims 1 to 6; The push rod is connected to the operating mechanism of the circuit breaker and rotates synchronously. During the closing process, the push rod passes through the first position and the second position of the circuit breaker in sequence, and the timing control system is connected to the electronic branch of the circuit breaker.

8. The timing control device for a hybrid solid-state DC circuit breaker according to claim 7, characterized in that: The circuit breaker is respectively equipped with a dial switch Q1 and an auxiliary switch Q2; The auxiliary switch Q2 is installed at the first position of the circuit breaker, and the dial switch Q1 is installed at the second position of the circuit breaker.

9. A hybrid solid-state DC circuit breaker, characterized in that: Includes the timing control system described in claim 7 or 8.

10. A high voltage electrical equipment, comprising the hybrid solid-state DC circuit breaker according to claim 9.

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