Zero-loss depth current limiting system

Abstract

The utility model discloses a zero-loss deep current limiting system, a controller, a superior switch and an electrical signal transmission system, a zero-loss deep current limiting device comprises a high-speed eddy current driving mechanism circuit breaker, a current limiting reactor and a current transformer, the high-speed eddy current driving mechanism circuit breaker is switched on to be in short circuit with the current limiting reactor during normal operation, and the current transformer is in short circuit with the current limiting reactor. The high-speed eddy current driving mechanism circuit breaker is connected in parallel with the current limiting reactor, and the current transformer is arranged in a main loop to collect current signals; the controller receives a current signal transmitted by the current transformer and controls the high-speed eddy current driving mechanism circuit breaker to be switched on and switched off; the upper-level switch receives intertripping signals from the controller; the electrical signal transmission system is composed of a cable and an optical cable and used for transmitting electrical signals among the zero-loss deep current limiting device, the controller and the superior switch, continuous energy consumption of a traditional current limiting device is avoided, zero-loss operation is achieved, and the operation cost is effectively reduced.

Description

Technical Field

[0001] This utility model belongs to the technical field of deep current limiting systems, specifically relating to a zero-loss deep current limiting system. Background Technology

[0002] In modern power system operation, short-circuit faults occur frequently, and short-circuit current levels continue to rise, making the problem of insufficient circuit breaker breaking capacity increasingly prominent. At the same time, traditional current limiting devices consume a lot of energy during operation, which not only causes a large amount of energy waste but also significantly increases the operating costs of the power system. Existing current limiting technologies are unable to effectively limit short-circuit current while achieving low-energy operation. Utility Model Content

[0003] The purpose of this invention is to provide a zero-loss deep current limiting system to address the technical shortcomings of existing current limiting devices, which consume a lot of energy during operation, resulting in significant energy waste and increased operating costs of the power system. Existing current limiting technologies are unable to effectively limit short-circuit current while achieving low-energy operation.

[0004] To achieve the above objectives, this utility model provides the following technical solution: a zero-loss deep current limiting system, a controller, an upstream switch, and an electrical signal transmission system. The zero-loss deep current limiting device includes a high-speed eddy current driven mechanism circuit breaker, a current limiting reactor, and a current transformer. When the high-speed eddy current driven mechanism circuit breaker is operating normally, it closes and short-circuits the current limiting reactor. The high-speed eddy current driven mechanism circuit breaker and the current limiting reactor are connected in parallel. The current transformer is located in the main circuit to collect current signals.

[0005] The controller is electrically connected to the zero-loss deep current limiting device, receives the current signal from the current transformer, and controls the opening and closing of the high-speed eddy current drive mechanism circuit breaker; the upstream switch receives the tripping signal from the controller; the electrical signal transmission system consists of cables and optical fibers, used to transmit electrical signals between the zero-loss deep current limiting device, the controller, and the upstream switch.

[0006] As a further embodiment of this utility model, the high-speed eddy current driven circuit breaker is model SPD-12kV / 1250A-40kA, with a tripping time ≤20ms.

[0007] As a further embodiment of this utility model, the maximum outer diameter of the zero-loss depth current limiting device is DC≤1200mm, the phase-to-phase distance is ≥1.7DC, the distance from the device to the obstacle is ≥1.1DC, the distance from the top obstacle is ≥0.5DC, the base is equipped with a grounding terminal, and each phase is equipped with a secondary line of a specific specification.

[0008] As a further embodiment of this utility model, the secondary line includes a 4×10mm² cable, a 2×2.5mm² cable, and a 6×1.5mm² cable for secondary circuit signal transmission.

[0009] As a preferred embodiment of this utility model, the rated voltage of the current-limiting reactor is 6.3kV.

[0010] As a preferred embodiment of this utility model, the controller model is ZLB-ZK.

[0011] Compared with existing technologies, the zero-loss deep current limiting system of this invention has the following advantages:

[0012] 1. When the present invention is in normal operation, the circuit breaker of the high-speed eddy current drive mechanism closes and short-circuits the current-limiting reactor, avoiding the continuous energy consumption of the traditional current-limiting device, realizing zero-loss operation, and effectively reducing operating costs.

[0013] 2. When a short circuit fault occurs in this utility model, the controller can control the high-speed eddy current drive mechanism circuit breaker to open within 20ms, quickly cut off the short circuit current and transfer it to the current-limiting reactor, rapidly limit the short circuit current, and protect the power system equipment from the impact of the short circuit current.

[0014] 3. After the short-circuit fault in this utility model is cleared, the controller automatically detects the current status and controls the high-speed eddy current drive mechanism circuit breaker to close, so that the current limiting device is restored to the "lossless" state without manual intervention, which improves the reliability and convenience of system operation.

[0015] 4. This utility model has a mechanism for handling the failure of lower-level branch protection. When it is determined that the lower-level branch protection has failed to operate, it can trip the upper-level switch and control the closing to prevent the reactor from overheating and burning out. At the same time, the system grounding is reliable and the secondary line configuration is reasonable, which improves the safety and stability of the power system operation. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only examples of embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the circuit structure of an embodiment of the present utility model;

[0018] Figure 2 This is a structural schematic diagram of an embodiment of the present utility model.

[0019] Figure label:

[0020] 1. Zero-loss deep current limiting device; 2. High-speed eddy current driven circuit breaker; 3. Current limiting reactor; 4. Current transformer; 5. Controller; 6. Upstream switch. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the embodiments of this utility model will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain this utility model and are not intended to limit this utility model.

[0022] In the description of the embodiments of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing the embodiments of this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this utility model.

[0023] In the description of the embodiments of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation", "connection" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, an integral connection, or a detachable connection; they can refer to the internal connection of two components; they can refer to a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the embodiments of this utility model can be understood according to the specific circumstances.

[0024] See appendix Figure 1-2 As shown, the zero-loss depth current limiting system of this utility model includes a zero-loss depth current limiting device 1, a controller 5, an upper-level switch 6, and an electrical signal transmission system. The zero-loss depth current limiting device 1 includes a high-speed eddy current driven circuit breaker 2, a current limiting reactor 3, and a current transformer 4.

[0025] When the high-speed eddy current driven mechanism circuit breaker 2 is operating normally, it closes and short-circuits the current-limiting reactor 3. The high-speed eddy current driven mechanism circuit breaker 2 and the current-limiting reactor 3 are connected in parallel. The current transformer 4 is located in the main circuit to collect the current signal. The controller 5 is electrically connected to the zero-loss deep current limiting device 1, receives the current signal from the current transformer 4, and controls the opening and closing of the high-speed eddy current driven mechanism circuit breaker 2. The upstream switch 6 receives the tripping signal from the controller 5. The electrical signal transmission system consists of cables and optical fibers, which are used to transmit electrical signals between the zero-loss deep current limiting device 1, the controller 5, and the upstream switch 6.

[0026] The above-mentioned technical solution of this utility model organically integrates the current limiting core component, control unit, upstream protection and signal transmission part, so that the system can work together. The short-circuit current is limited by the zero-loss deep current limiting device 1, the controller 5 makes decisions based on the current signal and controls the high-speed eddy current drive mechanism circuit breaker 2, the upstream switch 6 receives the trip command to cut off the circuit when necessary, and the electrical signal transmission system ensures smooth signal between the parts, and jointly ensures the safe and stable operation of the power system.

[0027] In this embodiment of the utility model, the high-speed eddy current driven circuit breaker 2 is model SPD-12kV / 1250A-40kA, with a tripping time of ≤20ms. This allows for rapid circuit disconnection at the moment a short-circuit fault occurs, effectively shortening the duration of the short-circuit current, reducing the impact and damage risk to power equipment, and improving the reliability of the power system.

[0028] In this embodiment of the utility model, the zero-loss depth current limiting device 1 has a maximum outer diameter DC≤1200mm, a phase-to-phase distance ≥1.7DC, a distance from the device to an obstacle ≥1.1DC, a distance from the top obstacle ≥0.5DC, a base equipped with a grounding terminal, and each phase equipped with a secondary line of a specific specification.

[0029] The above technical solutions avoid electrical faults, phase-to-phase short circuits, and equipment damage caused by external forces due to insufficient distance between equipment and between equipment and obstacles. They achieve standardized installation, reduce risks, and ensure reliable grounding of equipment by grounding terminals on the base to prevent leakage from endangering personnel and equipment safety. They also specify that each phase is equipped with secondary wires of a specific specification, standardize secondary circuit wiring, ensure stable signal transmission, and reduce potential faults.

[0030] In this embodiment of the invention, the secondary wiring includes a 4×10mm² cable, a 2×2.5mm² cable, and a 6×1.5mm² cable for secondary circuit signal transmission. By clearly defining the specifications of the secondary wiring, different cable specifications can be rationally allocated according to the characteristics of the secondary circuit signals, current magnitude, and signal type, ensuring accurate transmission of control signals, monitoring signals, etc., and guaranteeing the normal operation of the system's control and monitoring functions.

[0031] In this embodiment of the utility model, the rated voltage of the current-limiting reactor 3 is 6.3kV, which is compatible with the system voltage level. This ensures that the current can be effectively limited during short-circuit current limiting and that the reactor itself will not be damaged due to voltage mismatch. This ensures that the current limiting function is stable and reliable. The clearly defined rated voltage parameters make the reactor performance stable and reliable, and it can work in conjunction with other components of the system to improve the performance of the entire current limiting system.

[0032] In this embodiment of the utility model, the controller 5 is model ZLB-ZK, which can accurately receive the current transformer signal, quickly analyze and judge and accurately control the opening and closing of the high-speed eddy current drive mechanism circuit breaker 2, handle fault conditions, and ensure the reliable operation of the system.

[0033] In the normal operating state of this embodiment, the high-speed eddy current drive mechanism circuit breaker 2 is in the closed state, short-circuiting the current-limiting reactor 3. At this time, the current flows directly through the high-speed eddy current drive mechanism circuit breaker 2, and the current-limiting reactor 3 is not connected to the main circuit. The entire zero-loss deep current limiting device 1 operates in a "lossless" state, the power system supplies power normally, and there is almost no additional loss of electrical energy. The current transformer 4 monitors the main circuit current in real time and sends the collected current signal to the controller 5 through the electrical signal transmission system. The controller 5 analyzes the current signal in real time to determine whether the system is in a normal operating state.

[0034] When a short-circuit fault occurs in this embodiment of the invention, the short-circuit current increases instantaneously. The current transformer 4 detects the abnormally increased current signal and quickly transmits the signal to the controller 5. After receiving the short-circuit current signal, the controller 5 quickly analyzes and judges the situation. After confirming that a short-circuit fault has occurred, it issues a control command within 20ms. The command is transmitted to the high-speed eddy current drive mechanism circuit breaker 2 through the electrical signal transmission system. After receiving the tripping command, the high-speed eddy current drive mechanism circuit breaker 2 quickly trips the circuit using its high-speed eddy current drive mechanism, cutting off the short-circuit current in the main circuit. After the short-circuit current is cut off, it is transferred to the current-limiting reactor 3 connected in parallel with the high-speed eddy current drive mechanism circuit breaker 2. After the current-limiting reactor 3 is connected to the main circuit, it uses its own reactance characteristics to limit the short-circuit current, keeping the short-circuit current within the designed range, thereby protecting other equipment in the power system from damage caused by excessive short-circuit current.

[0035] After the feeder circuit breaker of this utility model successfully clears the short-circuit fault, the main circuit current gradually returns to the normal range. The current transformer 4 monitors the current change in real time and transmits the signal that the current has returned to normal to the controller 5. After the controller 5 detects that the current has returned to the normal range, it issues a closing command and sends the command to the high-speed eddy current drive mechanism circuit breaker 2 through the electrical signal transmission system. After receiving the closing command, the high-speed eddy current drive mechanism circuit breaker 2 closes again and short-circuits the current limiting reactor 3 again. The zero-loss deep current limiting device 1 returns to the "lossless" operating state, and the power system continues to supply power normally.

[0036] In this embodiment of the utility model, when a short-circuit fault occurs due to the failure of the lower-level branch protection to operate, after the high-speed eddy current drive mechanism circuit breaker 2 operates, if the current still has not returned to the normal range after a predetermined 2-second delay, the controller 5 determines that the lower-level protection or line switch has failed to operate. At this time, the controller 5 sends a signal to trip the low-voltage side outlet circuit breaker of the main transformer, i.e., the upper-level switch 6, through the electrical signal transmission system, so that the upper-level switch 6 cuts off the circuit and cuts off the short-circuit current from the source. On the other hand, it controls the high-speed eddy current drive mechanism circuit breaker 2 to close after a 100-ms delay, so as to prevent the current-limiting reactor 3 from overheating and burning out due to the long-term passage of a large current.

[0037] The foregoing has shown and described the basic principles of the present invention. The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. The above embodiments and descriptions in the specification are only illustrative of the principles of the present invention. Any modifications, equivalent substitutions, and improvements made within the scope of the present invention without departing from the scope of the present invention should be included within the protection scope of the present invention.

Claims

1. A zero-loss deep current limiting system, characterized in that: The system includes a zero-loss deep current limiting device (1), a controller (5), an upper-level switch (6), and an electrical signal transmission system. The zero-loss deep current limiting device (1) includes a high-speed eddy current driven mechanism circuit breaker (2), a current limiting reactor (3), and a current transformer (4). When the high-speed eddy current driven mechanism circuit breaker (2) is running normally, it closes and short-circuits the current limiting reactor (3). The high-speed eddy current driven mechanism circuit breaker (2) is connected in parallel with the current limiting reactor (3). The current transformer (4) is located in the main circuit to collect current signals. The controller (5) is electrically connected to the zero-loss deep current limiting device (1) to receive the current signal from the current transformer (4) and control the opening and closing of the high-speed eddy current drive mechanism circuit breaker (2). The upper-level switch (6) receives the trip signal from the controller (5); the electrical signal transmission system consists of cables and optical fibers, used to transmit electrical signals between the zero-loss deep current limiting device (1), the controller (5) and the upper-level switch (6); The high-speed eddy current driven circuit breaker (2) is model SPD-12kV / 1250A-40kA, with a tripping time ≤20ms; the zero-loss depth current limiting device (1) has a maximum outer diameter DC ≤1200mm, a phase-to-phase distance ≥1.7DC, a distance from the device to an obstacle ≥1.1DC, a distance from the top obstacle ≥0.5DC, a grounding terminal on the base, and each phase is equipped with a secondary wire of a specific specification; the secondary wire includes a 4×10mm 2 Cable, one 2×2.5mm 2 Cable and a 6×1.5mm 2 The cable is used for secondary circuit signal transmission; the rated voltage of the current limiting reactor (3) is 6.3kV; the controller (5) is model ZLB-ZK.

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