Hybrid solid-state circuit breaker and control method

Abstract

The invention discloses a hybrid solid-state circuit breaker and a control method, and belongs to the technical field of power equipment. The hybrid solid-state circuit breaker comprises a circuit breaker, a release and a fault clearing module; two mechanical switches K of the circuit breaker are connected in series between the positive electrode and the negative electrode of the mechanical circuit breaker, the mechanical switches are connected in parallel with fault clearing modules, and the mechanical switches K are connected with a release; the fault clearing unit comprises an electronic branch unit and an energy absorption unit which are connected in parallel; the electronic branch unit is used for converting arc energy generated by the action of the mechanical switch K to the energy absorption unit; the energy absorption unit is used for absorbing arc energy; the circuit breaker enables the mechanical contact to carry out switching-off operation under the condition of zero current and voltage, and solves the problem that the moving and static contacts are burnt by an electric arc generated in the switching-off process of a mechanical switch, and the problem that the service life of an electric appliance is shortened due to electric arc combustion.

Description

Technical Field

[0001] The present invention relates to the technical field of electric power equipment, and in particular to a hybrid solid-state circuit breaker and a control method thereof. Background Art

[0002] Low-voltage electrical appliances are electrical products with an AC voltage of up to 1140V and a DC voltage of up to 1500V. Existing low-voltage circuit breaker products, such as 250A frame circuit breakers, are often used in DC systems and require multi-pole series connection or an amplified arc extinguishing system to achieve higher product performance. Product performance requirements are getting higher and higher, and traditional products can no longer meet higher performance requirements. Existing low-voltage circuit breaker products, due to their principle structure, especially at high altitudes, often need to reduce voltage and current for use. Ordinary molded case circuit breakers can only be used at altitudes below 2000m. In this way, circuit breakers used at high altitudes generally need to reduce voltage and current. This is a method of use that requires a relatively high degree of professionalism, and ordinary customers cannot directly and accurately calculate the actual voltage and current after capacity reduction. Reluctant use may cause irreversible damage to electrical equipment or circuits.

[0003] Therefore, more and more low-voltage electrical appliance manufacturers are researching solid-state circuit breakers to improve product performance, 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 also required, so only some small current products (below 80A) can be put into formal application. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention provides a hybrid solid-state circuit breaker and a control method. When the fault clearing module interrupts the current, the arc voltage generated between the contacts connects the power electronic branch, and the current generated by the contact breaking is converted to the energy absorption branch, completing the arc extinguishing.

[0005] The present invention is achieved through the following technical solutions:

[0006] A hybrid solid-state circuit breaker includes a circuit breaker, a disconnect switch, and a fault clearing module;

[0007] The two mechanical switches K of the circuit breaker are connected in series, the two ends of the two mechanical switches K are connected to the positive and negative electrodes of the mechanical circuit breaker through an isolating switch, a fault clearing module is connected in parallel to the mechanical switch, and the mechanical switch K is connected to the release;

[0008] The fault clearing unit includes an electronic branch unit and an energy absorption unit connected in parallel;

[0009] The electronic branch unit is used to commutate the arc energy generated by the action of the mechanical switch K to the energy absorption unit;

[0010] The energy absorption unit is used to absorb arc energy.

[0011] Furthermore, the electronic branch unit is a transistor.

[0012] Furthermore, the transistor is an IGBT, and the collector and emitter of the IGBT are connected to two ends of the mechanical switch K respectively.

[0013] Furthermore, the energy absorption unit is a zinc oxide varistor, and both ends of the zinc oxide varistor are connected to the electronic branch unit.

[0014] Furthermore, the mechanical switch is connected to the positive and negative poles of the circuit breaker through an isolating switch.

[0015] Furthermore, the isolating switch includes two contact switches, the two contact switches are respectively connected in series at both ends of the two mechanical switches, and the two contact switches are respectively connected to the positive and negative poles of the circuit breaker.

[0016] Furthermore, the mechanical switch includes a stationary contact and a moving contact, and the contact switch is connected to the moving contact.

[0017] In a second aspect, the present application provides a control method for a hybrid solid-state circuit breaker, comprising the following process:

[0018] When a fault current occurs in the circuit, the release sends a control signal, the mechanical switch K operates, and the arc voltage generated by the operation of the mechanical switch K turns on the electronic branch unit, and the arc energy is transferred to the energy absorption unit, and the energy absorption unit absorbs the arc energy.

[0019] In a third aspect, the present application provides a high-voltage electrical equipment, including the hybrid solid-state DC circuit breaker.

[0020] In a fourth aspect, the present application provides an electric power system, including the above-mentioned high-voltage electrical equipment.

[0021] Compared with the prior art, the present invention has the following beneficial technical effects:

[0022] A hybrid solid-state circuit breaker provided by the present invention includes a circuit breaker and a fault clearing module. When an overload or short-circuit current occurs in the circuit, the tripper sends a control signal, the mechanical switch K is actuated, and the arc voltage generated by the action of the mechanical switch K turns on the electronic branch unit, and the arc energy is commutated to the energy absorption unit, and the energy absorption unit absorbs the arc energy. Thus, the mechanical contact is opened under zero current and voltage conditions, solving the problem of arc burning the moving and static contacts of the mechanical switch during the opening process, and the problem of reduced electrical appliance life caused by arc burning.

[0023] The present application also proposes a high-voltage electrical device and a power system, which possess all the advantages of the above-mentioned hybrid solid-state circuit breaker. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] 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.

[0025] Figure 1 A topological diagram of a fault current clearing module of the present invention;

[0026] Figure 2 It is a structural diagram of the hybrid solid-state circuit breaker of the present invention;

[0027] Figure 3 is an internal structure diagram of the hybrid solid-state circuit breaker of the present invention;

[0028] Figure 4 It is a structural diagram of the release of the present invention;

[0029] Figure 5 This is a schematic diagram of the connection between the fault current clearing module and the contact of the present invention;

[0030] Figure 6 It is a schematic diagram of the structure of the moving and static contacts of the present invention.

[0031] In the figure: 1. Rotary handle; 2. Disconnector; 3. Operating mechanism; 4. Fault current clearing module; 5. Contact arc extinguishing device; 6. Release; 7. Rotating shaft; 8. Arc extinguishing chamber; 9. Stationary contact; 10. Moving contact; 11. Direct-acting handle; 12. Mechanical switch; 41. Wire; 42. Wire. DETAILED DESCRIPTION

[0032] 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.

[0033] 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.

[0034] See also Figure 1 , a hybrid solid-state circuit breaker, comprising a circuit breaker and a fault clearing module;

[0035] Two mechanical switches K of the circuit breaker are connected in series between the positive and negative poles of the mechanical circuit breaker, a fault clearing module is connected in parallel to the mechanical switch, and the mechanical switch K is connected to the release of the circuit breaker;

[0036] The fault clearing unit includes an electronic branch unit and an energy absorption unit connected in parallel;

[0037] The electronic branch unit is used to commutate the arc energy generated by the action of the mechanical switch K to the energy absorption unit;

[0038] The energy absorption unit is used to absorb arc energy.

[0039] This hybrid solid-state circuit breaker, when the circuit breaker is working normally in the system, the pure mechanical switch maintains normal operation, but when there is a breaking current in the circuit, the arc voltage generated between the contacts of the mechanical switch causes the power electronic branch to be connected, and the current generated by the contact breaking is immediately converted to the energy absorption branch, thus completing the arc extinguishing.

[0040] In some embodiments, the electronic branch unit is a transistor, and the transistor is a field effect transistor or an insulated gate bipolar transistor, preferably an IGBT.

[0041] In this embodiment, the transistor is an IGBT, and the collector and emitter of the IGBT are connected to two ends of the mechanical switch K respectively.

[0042] The energy absorption unit is a zinc oxide varistor MOV or TVS tube, preferably MOV, the two ends of the zinc oxide varistor are respectively connected to the collector and emitter of the IGBT, and the transistor and the variable resistor are connected in parallel.

[0043] In some embodiments, the hybrid solid-state circuit breaker also includes an isolating switch, wherein two contact switches of the isolating switch are respectively connected in series at both ends of the two mechanical switches, and the two contact switches are respectively connected to the positive and negative poles of the circuit breaker, and the isolating switch is used to isolate the leakage current in the circuit.

[0044] In the hybrid solid-state circuit breaker of the present application, when an overload or short-circuit current occurs in the circuit, the release sends a signal to actuate the mechanical switch S3 and the mechanical switch S4. When the mechanical switch S3 and the mechanical switch S4 are actuated, an arc is generated between the contacts, the arc voltage causes the IGBT to actuate, the arc energy undergoes current conversion, and the current conversion enters the MOV to complete the entire disconnection process. Therefore, the hybrid solid-state circuit breaker will not generate a large amount of arcs due to the opening of the mechanical switch S3 and the mechanical switch S4, and the arc isolation plate of the existing circuit breaker is eliminated; during the control process, the circuit breaker uses a direct-acting handle 11 for closing and opening operations, and the isolating switch uses a rotating handle for closing and opening operations, thereby realizing independent operation of the circuit breaker and the isolating switch.

[0045] See also Figure 2-4 , the hybrid solid-state circuit breaker includes a circuit breaker and a disconnect switch 2.

[0046] The circuit breaker includes an operating mechanism 2, a contact arc extinguishing device 5 and a release 6; two contact arc extinguishing devices 5 are arranged in parallel and spaced apart, an operating structure 2 is arranged between the two contact arc extinguishing devices 5, a rotating shaft 7 of the operating structure 2 is connected to the contact arc extinguishing device 5, and controls the contact closing and opening of the mechanical switch in the contact arc extinguishing device 5, and the release 6 is arranged at the rear side of the contact arc extinguishing device, and the release realizes Figure 1 The role of RELEASE in the product. When the product fails such as overload, the operating mechanism is triggered to trip, and the tripping action causes the contacts in the contact arc extinguishing system to open to protect the circuit.

[0047] The mechanical switch includes a moving contact 10 and a stationary contact 9. The moving contact 10 rotates around the rotation center and cooperates with the stationary contact 9 to control the closing and opening. The arc extinguishing chamber helps the arc extinguishing of the two pairs of moving and stationary contacts. The stationary contacts 9 of the two mechanical switches are connected to the contact switch S3 and the contact switch S4.

[0048] See also Figure 5 and 6 At least two wires, wire 41 and wire 42, extend from the fault clearing module, connecting the moving contact 10 and the stationary contact 9 of the two mechanical switches respectively. The arc extinguishing chamber 8 helps extinguish the arc generated when the moving contact 10 and the stationary contact 9 are opened, and another part of the arc energy enters the fault clearing module through 41 and 42 for arc extinguishing.

[0049] In the hybrid solid-state circuit breaker of the present application, the contact switch S1 of the isolating switch is linked with the contact switch S2, and acts as an isolating contact. The mechanical switch S3 is linked with the mechanical switch S4, and acts as the main disconnecting contact of the circuit breaker. RELEASE is a short-circuit releaser, and is linked with the mechanical switch S3 and the mechanical switch S4. The mechanical switch S3 and the mechanical switch S4 are connected to the fault clearing module. The fault clearing module is provided with a power electronic unit and an energy absorption unit. When the main contact is disconnected, most of the current is transferred to the energy absorption device, which plays a good arc extinguishing role and protects the circuit. The release part can provide an overload action of a smaller current and a short-circuit disconnecting action of a larger current. When disconnected, the circuit energy flows from the main disconnecting contact mechanical switch S3 and the mechanical switch S4 into the fault clearing module.

[0050] The control method of the hybrid solid-state circuit breaker includes the following process:

[0051] When an overload or short-circuit current occurs in the circuit, the release sends a control signal, and the mechanical switch K operates. The arc voltage generated by the operation of the mechanical switch K turns on the electronic branch unit, and the arc energy is transferred to the energy absorption unit, and the energy absorption unit absorbs the arc energy.

[0052] The present application also provides a high-voltage electrical equipment, including the hybrid solid-state DC circuit breaker described in Example 2.

[0053] An electric power system comprises the high-voltage electrical equipment described in Example 3.

[0054] The power system includes substations, industrial power grids, distribution systems, high-voltage transmission grids, new energy power generation systems, etc.

[0055] 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 hybrid solid-state circuit breaker, characterized in that: Includes circuit breakers, disconnect switches and fault clearing modules; The two mechanical switches K of the circuit breaker are connected in series, the two ends of the two mechanical switches K are connected to the positive and negative electrodes of the mechanical circuit breaker through an isolating switch, a fault clearing module is connected in parallel to the mechanical switch, and the mechanical switch K is connected to the release; The fault clearing unit includes an electronic branch unit and an energy absorption unit connected in parallel; The electronic branch unit is used to commutate the arc energy generated by the action of the mechanical switch K to the energy absorption unit; The energy absorption unit is used to absorb arc energy.

2. A hybrid solid-state circuit breaker according to claim 1, characterized in that: The electronic branch circuit unit is a transistor.

3. A hybrid solid-state circuit breaker according to claim 2, characterized in that: The transistor is an IGBT, and the collector and emitter of the IGBT are connected to two ends of the mechanical switch K respectively.

4. A hybrid solid-state circuit breaker according to claim 1, characterized in that: The energy absorption unit is a zinc oxide varistor, and two ends of the zinc oxide varistor are connected to the electronic branch unit.

5. A hybrid solid-state circuit breaker according to claim 1, characterized in that: The mechanical switch is connected to the positive and negative poles of the circuit breaker through an isolating switch.

6. A hybrid solid-state circuit breaker according to claim 5, characterized in that: The isolating switch comprises two contact switches, which are respectively connected in series at two ends of two mechanical switches, and the two contact switches are respectively connected to the positive and negative poles of the circuit breaker.

7. A hybrid solid-state circuit breaker according to claim 6, characterized in that: The mechanical switch comprises a stationary contact and a moving contact, and the contact switch is connected to the moving contact.

8. A control method for a hybrid solid-state circuit breaker according to any one of claims 1 to 7, characterized in that: The process includes: When a fault current occurs in the circuit, the release sends a control signal, the mechanical switch K operates, and the arc voltage generated by the operation of the mechanical switch K turns on the electronic branch unit, and the arc energy is transferred to the energy absorption unit, and the energy absorption unit absorbs the arc energy.

9. A high voltage electrical equipment, characterized in that: A hybrid solid-state DC circuit breaker comprising the hybrid solid-state DC circuit breaker according to any one of claims 1 to 7.

10. A power system, characterized in that: Including the high-voltage electrical equipment described in claim 9.

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