A switch system for fast switching of power supply in distribution network

Abstract

The present invention discloses a switch system for fast switching of power supply in a distribution network, comprising: a vacuum circuit breaker and a gas gap switch connected in parallel, and a controller respectively connected to the vacuum circuit breaker and the gas gap switch in communication; the vacuum circuit breaker is used to undertake the task of opening and closing the line; the gas gap switch is used to undertake the task of closing the line, and the closing speed of the gas gap switch is greater than the closing speed of the vacuum circuit breaker; the controller is used to send an opening / closing signal to the vacuum circuit breaker, and to send a trigger signal to the gas gap switch; the vacuum circuit breaker and the gas gap switch respectively send corresponding status signals to the controller. The present invention combines the vacuum circuit breaker with the gas gap switch, can complete fast switching of power supply within the power frequency cycle, and has a long trigger life and strong current carrying capacity, which is beneficial to reducing the significant losses and serious harm caused by temporary voltage sag or even voltage interruption in the distribution network.

Description

Technical Field

[0001] The invention relates to the technical field of fast control and protection switches for distribution networks, and in particular to a switch system for fast switching of power supplies for distribution networks. Background Art

[0002] With the rapid development of smart distribution networks, switchgear not only meets the conventional opening and closing requirements, but also has a large number of special application requirements for rapid control and protection. Traditional power switchgear uses spring and hydraulic operating mechanisms, both of which have a closing time of tens of milliseconds, and the problem of insufficient rapid control and protection capabilities is becoming more and more prominent; high-voltage and large-capacity power electronic switches require multiple components to be used in series and parallel, which is complex in structure and expensive. Summary of the invention

[0003] In order to overcome the defects in the above-mentioned prior art, the present invention provides a switch system for fast switching of power supply in a distribution network, which combines a vacuum circuit breaker with a gas gap switch to achieve fast switching of power supply.

[0004] To achieve the above object, the present invention adopts the following technical solutions, including:

[0005] A switch system for fast switching of power supply in a distribution network, the switch system comprising: a vacuum circuit breaker and a gas gap switch connected in parallel, and a controller respectively connected in communication with the vacuum circuit breaker and the gas gap switch;

[0006] The vacuum circuit breaker is used to undertake the task of opening and closing the line; the gas gap switch is used to undertake the task of closing the line; the touch-on time of the gas gap switch is shorter than the closing time of the vacuum circuit breaker; the controller is used to send an opening / closing signal to the vacuum circuit breaker, and to send a trigger signal to the gas gap switch.

[0007] Preferably, if the switch system is used to cut off the power supply to the load, the controller sends a trip signal to the vacuum circuit breaker.

[0008] Preferably, if the switch system is used to introduce power to the load, the controller sends a trigger signal to the gas gap switch and simultaneously sends a closing signal to the vacuum circuit breaker. After the gas gap switch receives the trigger signal and is turned on, the power supply supplies power to the load through the gas gap switch branch. After the vacuum circuit breaker completes the closing action and the arc in the gas gap switch is extinguished, the power supply supplies power to the load through the line of the vacuum circuit breaker.

[0009] Preferably, the power supply of the distribution network includes a main power supply and a backup power supply; the switch system is respectively arranged between each power supply and the load.

[0010] Preferably, the vacuum circuit breaker and the gas gap switch respectively send corresponding status signals to the controller.

[0011] Preferably, the touch-on time of the gas gap switch is less than 0.2 ms.

[0012] Preferably, the vacuum circuit breaker adopts a hybrid operating mechanism, including a permanent magnet mechanism and an electromagnetic repulsion mechanism;

[0013] The permanent magnet mechanism serves as a closing mechanism to provide closing holding force;

[0014] The repulsion mechanism serves as a tripping mechanism, and relies on the capacitor to discharge the coil disk, thereby generating eddy currents in the repulsion disk, so as to complete the tripping action.

[0015] Preferably, the gas gap switch comprises: a high voltage electrode, a ground electrode, a trigger chamber, and a trigger circuit;

[0016] The high voltage electrode and the ground electrode are parallel to each other;

[0017] The trigger chamber is composed of a ground electrode, a trigger needle electrode, and an insulating member; a spray hole is opened at the top of the ground electrode, the insulating member is placed inside the ground electrode facing the spray hole, and the trigger needle electrode is placed inside the insulating member facing the spray hole, and the ground electrode, the trigger needle electrode, and the insulating member are tightly abutted;

[0018] The high-voltage electrode is connected to high-voltage direct current; the ground electrode is grounded; and the trigger needle electrode is connected to the trigger loop.

[0019] Preferably, the trigger circuit includes: a pulse transformer T, a pulse capacitor C, a diode D, a resistor R, and a thyristor SCR;

[0020] The pulse transformer T includes a primary side T1 and a secondary side T2; one end of the pulse capacitor C is connected to the a end of the primary side T1, and the other end of the pulse capacitor C is grounded; the negative end of the diode D is connected to the b end of the primary side T1, and the positive end of the diode D is grounded; one end of the resistor R is connected to the b end of the secondary side T2, and the other end of the resistor R is connected to the ground electrode; the positive end of the thyristor SCR is connected to the b end of the primary side T1, and the negative end of the thyristor SCR is connected in parallel with the diode D and then connected to the ground end of the pulse capacitor C; the a end of the secondary side T2 is connected to the trigger needle electrode.

[0021] Preferably, the thyristor SCR responds to the trigger signal sent by the controller. After receiving the trigger signal, the thyristor SCR controls the pulse capacitor C to discharge, generates a high-voltage pulse through the pulse transformer T, triggers the trigger needle electrode to discharge to the trigger cavity, and the arc current burns the insulating part. After the plasma accumulates, it is sprayed into the main gap between the high-voltage electrode and the ground electrode at a high pressure at the injection hole, providing initial charged particles to induce the main gap breakdown, and the gas gap switch is turned on.

[0022] The advantages of the present invention are:

[0023] (1) Compared with traditional power switchgear and high-voltage and large-capacity power electronic switches, the switch system for rapid switching of power supply in a distribution network described in the present invention combines a vacuum circuit breaker with a gas-gap switch to achieve rapid switching of power supply.

[0024] (2) The present invention combines a vacuum circuit breaker with a gas-gap switch, which can quickly switch power within the power frequency cycle, and has a long trigger life and strong current-carrying capacity, which is beneficial to reducing the significant losses and serious damage caused by temporary voltage drops or even voltage interruptions in the distribution network.

[0025] (3) The present invention realizes flexible control of ultra-fast opening and closing by integrating the gas gap switch and the fast vacuum circuit breaker through the controller, has a long trigger life, meets the requirements of fast power switching, and has low cost and high withstand voltage and current parameters.

[0026] (4) In the jet plasma triggered gas gap switch, the arc current in the trigger chamber ablates the insulating part, i.e., the polytetrafluoroethylene gas-generating material, to generate plasma, which accumulates in large quantities and is then ejected at high pressure at the ejection hole to provide the initial electrons for the breakdown discharge of the gas gap. The electrons rapidly develop in the main gap, causing the electric field between the plasma head and the high-voltage electrode to be severely distorted, and the main gap is induced to break down, thus realizing the rapid and stable conduction of the gas gap switch at a relatively low operating voltage, i.e., working coefficient, and low trigger energy. The device has a simple structure, low cost, high withstand voltage and flow parameters, and has significant technical and economic advantages and broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is the structural diagram of the switch system.

[0028] Figure 2 A topological diagram of a switch system for fast switching of power supply in a distribution network.

[0029] Figure 3 This is the circuit diagram of the gas gap switch trigger device.

[0030] Figure 4 Schematic diagram of the trigger chamber of the plasma jet triggered gas gap switch. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] Depend on Figure 1As shown, a switch system for fast switching of power supply in a distribution network includes: a vacuum circuit breaker 10 and a gas gap switch 20 connected in parallel, and a controller 30 communicatively connected to the vacuum circuit breaker 10 and the gas gap switch 20 respectively.

[0033] The vacuum circuit breaker 10 is used to undertake the task of opening and closing the line; the gas gap switch 20 is used to undertake the task of closing the line, and the closing speed of the gas gap switch 20 is greater than the closing speed of the vacuum circuit breaker 10; the controller 30 is used to send an opening / closing signal to the vacuum circuit breaker 10, and to send a trigger signal to the gas gap switch 20; the vacuum circuit breaker 10 and the gas gap switch 20 respectively send corresponding status signals to the controller 30.

[0034] If the switch system is used to cut off the power supply to the load, the controller 30 sends a trip signal to the vacuum circuit breaker 10 .

[0035] If the switch system is used to turn on the power supply to the load, the controller 30 sends a trigger signal to the gas gap switch 20 and simultaneously sends a closing signal to the vacuum circuit breaker 10. After receiving the trigger signal, the gas gap switch 20 is first turned on, and the power supply to the load is supplied through the line of the gas gap switch 20. After the vacuum circuit breaker completes the closing action and the arc in the gas gap switch 20 is extinguished, the power supply to the load is supplied through the line of the vacuum circuit breaker 10.

[0036] The power supply of the distribution network includes the main power supply and the backup power supply. Figure 2 As shown, a first switch system is set between the main power supply and the load, and a second switch system is set between the backup main power supply and the load. Under normal conditions, the main power supply is used to power the load; when the main power supply fails, the first switch system is used to quickly cut off the power supply of the main power supply to the load, and the second switch system is used to synchronously and quickly turn on the power supply of the backup power supply to the load.

[0037] The first switch system includes a first vacuum circuit breaker 11 and a first gas gap switch 21; the second switch system includes a second vacuum circuit breaker 12 and a second gas gap switch 22; the first switch system and the second switch system are connected using the same controller 30, and the controller 30 is also used for power supply fault detection.

[0038] When the controller 30 detects a main power failure, the controller 30 sends a trip signal to the first vacuum circuit breaker 11. After receiving the trip signal, the first vacuum circuit breaker 11 achieves rapid and stable tripping within a few milliseconds, thereby cutting off the power supply of the first power supply to the load. After the first vacuum circuit breaker 11 is actuated, the status signal is sent to the controller 30. At the same time, the controller 30 sends a closing signal and a trigger signal to the second vacuum circuit breaker 12 and the second gas gap switch 12 respectively. After receiving the trigger signal, the second gas gap switch 22 quickly acts within a few hundred microseconds, the second gas gap switch 22 is turned on, and the load is quickly connected to the power supply 2 through the line of the second gas gap switch 22 to continue to flow, and normal operation is immediately restored. The second vacuum circuit breaker 12 receives the closing signal. The contacts are closed within ten milliseconds, and the working current of the load is transferred from the line of the second gas gap switch 22 to the line of the second vacuum circuit breaker 12. The arc in the second gas gap switch 22 is extinguished, and the power supply supplies power to the load through the line of the first vacuum circuit breaker 11. After the second gas gap switch 22 and the second vacuum circuit breaker 12 act, the status signal is sent to the controller 30.

[0039] The first vacuum circuit breaker 11 is opened quickly and stably within 3 ms, the second gas gap switch 12 is turned on within a very short time of 100 microseconds, and the second vacuum circuit breaker 12 is closed within 10 ms.

[0040] If the backup power supply is in normal power supply, it is equivalent to the main power supply, and the main power supply is the backup power supply. Through a similar control process, the backup power supply can be quickly switched and repeated power switching can be achieved.

[0041] In the present invention, the vacuum circuit breaker 10 and the gas gap switch 20 are connected to the controller through optical fiber cables and are shielded by aluminum shielding wires. The aluminum shielding wires can prevent the spatial electromagnetic disturbances generated by the test from interfering with the triggering of the power fast switching switch system.

[0042] In the present invention, the vacuum circuit breaker 10 adopts a hybrid operating mechanism, including a permanent magnet mechanism and an electromagnetic repulsion mechanism. The permanent magnet mechanism is used as a closing mechanism to provide a closing holding force, and the repulsion mechanism is used as an opening mechanism to discharge the coil disk by a capacitor to generate eddy currents in the repulsion disk to quickly complete the opening action.

[0043] In the present invention, Figure 3 As shown, the gas gap switch 20 is a plasma jet triggered gas gap switch, comprising: a high voltage brass flat electrode, namely a high voltage electrode 41, a low voltage brass flat electrode, namely a ground electrode 42, a trigger chamber, and a trigger circuit.

[0044] The high voltage electrode 41 and the ground electrode 42 are arranged in an internal closed space formed by the gas gap switch cavity. The high voltage electrode 41 and the ground electrode 42 are parallel to each other to form a main gap.

[0045] Depend on Figure 4 As shown, the trigger chamber is composed of a ground electrode 42, a trigger needle electrode 43, and an insulating member 44; a spray hole 421 is opened at the top of the ground electrode 42, and the insulating member 44 is placed inside the ground electrode 42 opposite to the spray hole 421, and the trigger needle electrode 43 is placed inside the insulating member opposite to the spray hole 421, and the spray hole 421 is communicated with the insulating member 44, and the insulating member 44 is placed between the trigger needle electrode 43 and the ground electrode 42, and the three are closely abutted. In this embodiment, the insulating member 44 is polytetrafluoroethylene.

[0046] The trigger circuit includes: a pulse transformer T, a pulse capacitor C, a diode D, a resistor R, and a thyristor SCR.

[0047] The pulse transformer T includes a primary side T1 and a secondary side T2; one end of the pulse capacitor C is connected to the a end of the primary side T1, and the other end of the pulse capacitor C is grounded; the negative end of the diode D is connected to the b end of the primary side T1, and the positive end of the diode D is grounded; one end of the resistor R is connected to the b end of the secondary side T2, and the other end of the resistor R is connected to the ground electrode 42; the positive end of the thyristor SCR is connected to the b end of the primary side T1, and the negative end of the thyristor SCR is connected in parallel with the diode D and then connected to the ground end of the pulse capacitor C; the a end of the secondary side T2 is connected to the trigger needle electrode 43.

[0048] The high voltage electrode 41 is connected to a high voltage direct current source, the ground electrode 42 is grounded, and the trigger needle electrode 43 is connected to the primary side T1 .

[0049] The thyristor SCR responds to the trigger signal sent by the controller. When the thyristor SCR receives the trigger signal, the thyristor SCR controls the pulse capacitor C to discharge, generates a high-voltage pulse through the pulse transformer T, and applies it to the trigger needle electrode 43 to discharge to the trigger cavity. The arc current ablates the gas-generating material of the insulating member 44, and the ionized ablation product generates plasma. After a large amount of accumulation, it is sprayed into the main gap between the high-voltage electrode 41 and the ground electrode 42 at the injection hole 421 with high gas pressure, so that the field intensity is distorted and the initial charged particles are provided to induce gap breakdown. When the thyristor SCR does not receive the trigger signal, no pulse high voltage is output to the trigger needle electrode 43 of the trigger cavity.

[0050] The triggering process of the gas gap switch 20 is as follows:

[0051] A positive DC high voltage is applied between the high voltage electrode and the ground electrode of the gas gap switch to charge the pulse capacitor so that the capacitor voltage reaches a predetermined value. The thyristor SCR responds to the trigger command, and the pulse capacitor outputs a high voltage pulse through the pulse transformer, causing the insulating part to flash over along the surface, ionizing the ablation product of the insulating gas-generating material to generate plasma, which is ejected from the injection hole 421 under the action of high temperature and high pressure in the cavity, inducing the main gap to break down.

[0052] In this embodiment, the vacuum circuit breaker has a rated voltage of 12kV, a rated current of 1250A, a rated breaking current of 31.5kA, a mechanical life of up to 5000 times, a break time of 3±0.2ms, and a closing time of 10±0.5ms. The gas gap switch has a rated voltage of 12kV, a rated current of 1250A, a minimum triggerable voltage of 2-3kV, a contact time of <0.2ms, a current carrying capacity of 80kA / 10ms, 30 times, and a trigger life of up to 2000 times.

[0053] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A switch system for fast switching of power supply in a distribution network, characterized in that: The switch system comprises: a vacuum circuit breaker (10) and a gas gap switch (20) connected in parallel, and a controller (30) respectively connected to the vacuum circuit breaker (10) and the gas gap switch (20); The vacuum circuit breaker (10) is used to undertake the task of opening and closing the line; the gas gap switch (20) is used to undertake the task of closing the line; the touch-on time of the gas gap switch (20) is shorter than the closing time of the vacuum circuit breaker (10); the controller (30) is used to send an opening / closing signal to the vacuum circuit breaker (10), and to send a trigger signal to the gas gap switch (20); If the switch system is used to introduce a power supply to supply power to a load, the controller (30) sends a trigger signal to the gas gap switch (20) and simultaneously sends a closing signal to the vacuum circuit breaker (10); after the gas gap switch (20) receives the trigger signal and is turned on, the power supply supplies power to the load through a branch of the gas gap switch (20); after the vacuum circuit breaker completes the closing action and the arc in the gas gap switch (20) is extinguished, the power supply supplies power to the load through a line of the vacuum circuit breaker (10); The power supply of the distribution network includes a main power supply and a backup power supply; the switch system is respectively arranged between each power supply and the load.

2. A switch system for rapid switching of power supply in a distribution network according to claim 1, characterized in that: If the switch system is used to cut off the power supply to the load, the controller (30) sends a trip signal to the vacuum circuit breaker (10).

3. A switch system for fast switching of power supply in a distribution network according to claim 1 or 2, characterized in that: The vacuum circuit breaker (10) and the gas gap switch (20) respectively send corresponding status signals to the controller (30).

4. A switch system for rapid switching of power supply in a distribution network according to claim 1 or 2, characterized in that: The touch-on time of the gas gap switch (20) is less than 0.2 ms.

5. A switch system for rapid switching of power supply in a distribution network according to claim 1, characterized in that: The vacuum circuit breaker adopts a hybrid operating mechanism, including a permanent magnet mechanism and an electromagnetic repulsion mechanism; The permanent magnet mechanism serves as a closing mechanism to provide closing holding force; The repulsion mechanism serves as a tripping mechanism, and relies on the capacitor to discharge the coil disk, thereby generating eddy currents in the repulsion disk, so as to complete the tripping action.

6. A switch system for rapid switching of power supply in a distribution network according to claim 1, characterized in that: The gas gap switch (20) comprises: a high voltage electrode (41), a ground electrode (42), a trigger chamber, and a trigger circuit; The high voltage electrode (41) and the ground electrode (42) are parallel to each other; The trigger chamber is surrounded by a ground electrode (42), a trigger needle electrode (43), and an insulating member (44); a spray hole (421) is provided at the top of the ground electrode (42); the insulating member (44) is arranged inside the ground electrode (42) facing the spray hole (421); the trigger needle electrode (43) is arranged inside the insulating member facing the spray hole (421); the ground electrode (42) and the insulating member (44) are in close contact with each other; and the insulating member (44) and the trigger needle electrode (43) are in close contact with each other; The high-voltage electrode (41) is connected to a high-voltage direct current; the ground electrode (42) is grounded; and the trigger needle electrode (43) is connected to the trigger circuit.

7. A switch system for rapid switching of power supply in a distribution network according to claim 6, characterized in that: The trigger circuit includes: a pulse transformer T, a pulse capacitor C, a diode D, a resistor R, and a thyristor SCR; The pulse transformer T comprises a primary side T1 and a secondary side T2; one end of the pulse capacitor C is connected to the a end of the primary side T1, and the other end of the pulse capacitor C is grounded; the negative end of the diode D is connected to the b end of the primary side T1, and the positive end of the diode D is grounded; one end of the resistor R is connected to the b end of the secondary side T2, and the other end of the resistor R is connected to the ground electrode (42); the positive end of the thyristor SCR is connected to the b end of the primary side T1, and the negative end of the thyristor SCR is connected in parallel with the diode D and then connected to the ground end of the pulse capacitor C; the a end of the secondary side T2 is connected to the trigger needle electrode (43).

8. A switch system for rapid switching of power supply in a distribution network according to claim 7, characterized in that: The thyristor SCR responds to a trigger signal sent by a controller. After receiving the trigger signal, the thyristor SCR controls the pulse capacitor C to discharge, generates a high-voltage pulse through a pulse transformer T, triggers the trigger needle electrode (43) to discharge into the trigger chamber, and the arc current burns the insulating member (44). After plasma accumulates, it is sprayed into the main gap between the high-voltage electrode (41) and the ground electrode (42) at a high pressure at the spray hole (421), providing initial charged particles to induce the main gap to break down, and the gas gap switch (20) is turned on.

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