Capacitance electricity taking circuit for primary and secondary fusion pole-mounted circuit breaker

Abstract

A capacitance electricity-taking circuit for a primary and secondary fusion pole-mounted circuit breaker comprises a first electricity-taking capacitor and a second electricity-taking capacitor which are connected in series, and a transformer which is connected with the second electricity-taking capacitor in parallel through a high-voltage side, and the low-voltage side of the transformer is connected with an output end. The first end, connected with the first electricity taking capacitor, of the second electricity taking capacitor is grounded and connected with a current discharging access, a discharging tube is arranged on the current discharging access, the control end of the discharging tube is connected with a discharging control circuit, and the discharging control circuit comprises a first protection diode. The second end of the second electricity taking capacitor is connected with the negative electrode of the first protection diode, and the positive electrode of the first protection diode is connected with the control end of the bleeder tube. According to the utility model, grounding protection and overvoltage protection of the input end can be realized at the same time by using the current discharge path, synchronous protection when the input end is abnormal can be realized by using the no-load protection circuit of the output end, and multiple protection functions are realized through circuit multiplexing.

Description

TECHNICAL FIELD

[0001] The utility model belongs to power technical field, concretely relates to a capacitor electricity taking circuit for primary and secondary fusion pole circuit breaker. BACKGROUND

[0002] Primary and secondary fusion pole circuit breaker refers to the primary equipment such as circuit breaker body, mutual inductor and the secondary equipment such as power distribution automation terminal, protection device, communication module are integrated and collaborative design deeply, realize the integrated distribution switch equipment of function fusion, for the mode of electricity taking from primary and secondary fusion pole circuit breaker, the prior art mainly has two, PT (voltage transformer) electricity taking and capacitor voltage division electricity taking. Wherein, PT electricity taking is to connect the two interfaces of transformer high voltage coil to two-phase live line respectively, and the low voltage side outputs electric energy. PT electricity taking is limited by the inductance of high voltage coil, if the ferromagnetic resonance occurs, the whole electricity taking device will burn out, and PT is large in size, and it is inconvenient to install on site, if secondary circuit is short-circuited, it can cause primary circuit to burn out. Relative to PT electricity taking, capacitor electricity taking has the advantages of small size and low cost, but it is easy to burn directly under overvoltage and lightning, and it requires high grounding, and there is great safety hazard if grounding is unreliable. The existing electricity taking circuit is usually provided with a protection circuit, and the protection circuit adopts a current discharge path for inductance or overvoltage, which causes the circuit to be complex and the cost to be increased. UTILITARIAN CONTENT

[0003] In order to improve the defects of the existing capacitor electricity taking technology, the utility model discloses a capacitor electricity taking circuit for primary and secondary fusion pole circuit breaker.

[0004] The capacitor electricity taking circuit for primary and secondary fusion pole circuit breaker, including the first electricity taking capacitor and the second electricity taking capacitor in series, and the transformer in parallel with the high voltage side and the second electricity taking capacitor, the voltage output positive terminal is connected to the low voltage side of the transformer, characterized in that, the first end of the second electricity taking capacitor and the first electricity taking capacitor is connected to the ground and is provided with a current discharge path, the current discharge path is provided with a discharge tube, and the control end of the discharge tube is connected with a discharge control circuit, the discharge control circuit includes a first protection diode, the second end of the second electricity taking capacitor is connected to the negative electrode of the first protection diode, and the positive electrode of the first protection diode is connected to the control end of the discharge tube.

[0005] Preferably, the discharge tube is a plurality of, adopts the connection mode of series connection, and an inductor is connected in series between the second electricity taking capacitor and the first discharge tube.

[0006] Preferably, the bleed control circuit further comprises a second protection diode, the negative pole of the second protection diode is connected to the common end of the first power capacitor and the second power capacitor, and the positive pole of the second protection diode is connected to the control end of the bleeder tube.

[0007] Preferably, the bleeder tube is BT131-800D, and the first protection diode and the second protection diode are both p6KE520CA.

[0008] Preferably, resistors are connected between the first protection diode, the second protection diode and the control end of the bleeder tube.

[0009] Preferably, the capacitor power circuit further comprises a no-load protection circuit arranged at the positive end of the voltage output, the no-load protection circuit comprises a full-bridge rectifier circuit, and a third protection diode and a fourth resistor are connected in series between the positive end of the voltage output and the negative end of the voltage output, two input ends of the full-bridge rectifier circuit are respectively connected to two ends of the low-voltage side of the transformer, and two output ends of the full-bridge rectifier circuit are connected to the positive end of the voltage output and the negative end of the voltage output; a power tube and an energy storage capacitor are further connected in parallel between the positive end of the voltage output and the negative end of the voltage output, and the base of the power tube is connected to the common end of the third protection diode and the fourth resistor.

[0010] Preferably, the capacitor power circuit further comprises a coupling circuit, the coupling circuit comprises an optical coupler, the input end of the optical coupler is connected to the control end of the bleeder tube, and the two output ends of the optical coupler are respectively connected to the positive end and the negative end of the third protection diode.

[0011] Preferably, a sixth resistor is connected in series at the input end of the optical coupler.

[0012] The capacitor power circuit for the primary and secondary fusion pole-mounted circuit breaker has the advantages that the current discharge path can simultaneously realize the ground protection and overvoltage protection of the input end, the no-load protection circuit of the output end can realize the synchronous protection when the input end is abnormal, and various protection functions are realized through circuit multiplexing. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 It is a specific embodiment schematic diagram of the capacitor power circuit for the primary and secondary fusion pole-mounted circuit breaker.

[0014] Figure 2 It is a specific embodiment principle block diagram schematic diagram of the capacitor power circuit for the primary and secondary fusion pole-mounted circuit breaker.

[0015] The figure mark name is: TV - bleed pipe, L - inductance, R1 - first resistance, R2 - second resistance, R3 - third resistance, R4 - fourth resistance, R5 - ground virtual resistance, R6 - sixth resistance, D1 - first protection diode, D2 - second protection diode, D3 - third protection diode, D4 - full-bridge rectifier circuit, C1 - first power capacitor, C2 - second power capacitor, C3 - energy storage capacitor, VIN - voltage input end, VOP - voltage output positive end, VON - voltage output negative end, M - power tube, G - optical coupling. DETAILED DESCRIPTION

[0016] The specific embodiment of the utility model is further explained in detail below in combination with the drawings.

[0017] As shown in Figure 1 and Figure 2 , the capacitor power circuit for a primary and secondary fusion column circuit breaker, including the first power capacitor C1 and the second power capacitor C2 in series, and the transformer T in parallel with the second power capacitor C2 on the high voltage side, the transformer T low voltage side is connected with the output end, the second power capacitor C2 and the first power capacitor C1 connected first end to ground between the connection has the current discharge channel, the current discharge channel is provided with the bleed pipe TV, the control end of the bleed pipe TV is connected with the discharge control circuit, the discharge control circuit includes the first protection diode D1, the second end of the second power capacitor C2 is connected with the negative pole of the first protection diode D1, and the positive pole of the first protection diode D1 is connected with the control end of the bleed pipe TV.

[0018] The first power capacitor C1 and the second power capacitor C2 are connected in series between the voltage input end VIN and the ground, and the second end of the second power capacitor C2 is separately grounded. The transformer realizes AC voltage division power supply through the capacitor, and takes power from the transformer at both ends of the second power capacitor C2 and outputs from the voltage output positive end VOUT. When normally taking power, the bleed pipe TV and the first protection diode D1 are not conductive.

[0019] By connecting the first protection diode D1 at the second end of the second power capacitor C2, when the grounding end of the second power capacitor C2 cannot withstand large current due to lightning or other reasons, as shown in Figure 1 , specifically, the ground virtual resistance R5 between the second power capacitor C2 and the ground changes from an ideal near-zero resistance to an unpredictable increased resistance, so that the voltage at the second end of the second power capacitor C2 rises rapidly in the large current state, breaking the first protection diode D1. After the first protection diode D1 is broken, the voltage at the control end of the bleed pipe TV rises, the bleed pipe TV opens, and the accumulated charge on the second power capacitor C2 is discharged.

[0020] The bleed-off tube TV can adopt a bidirectional thyristor, and the gate is used as the control end. The bleed-off tube can adopt a single tube or a plurality of tubes in series to improve the withstand voltage. In one embodiment, the bleed-off tube adopts BT131-800D, and the first protection diode and the second protection diode adopt p6KE520CA. When a plurality of tubes in series are adopted, as shown in FIG. 8, an inductor L needs to be connected in series between the second power-taking capacitor C2 and the first bleed-off tube. Due to the process manufacturing difference, the bleed-off tubes cannot be opened at the same time. The transient high voltage during the bleed-off will almost all fall on the bleed-off tube that is not opened, and the inductor L can absorb the transient high voltage to protect the bleed-off tube. Figure 1

[0021] Figure 1 In the embodiment shown in FIG. 8, the bleed-off path can also be used to realize the conventional high-voltage protection. The bleed-off control circuit further includes a second protection diode D2. The first end voltage of the second power-taking capacitor C2 is connected to the negative electrode of the second protection diode D2. The positive electrode of the second protection diode D2 is connected to the control end of the bleed-off tube TV. When the first end voltage of the second power-taking capacitor C2 is abnormally increased due to the power grid disturbance or other reasons, the second protection diode D2 is broken down, and the bleed-off tube TV is also opened to discharge the current through the current bleed-off path. Figure 1 In the embodiment shown in FIG. 8, the inductor L, the second protection diode D2, and the first protection diode D1 are respectively connected in series with a first resistor R1, a second resistor R2, and a third resistor R3 to limit the current flowing through the corresponding devices.

[0022] As shown in FIG. 8, the capacitor power-taking circuit further includes a no-load protection circuit arranged at the positive end of the voltage output. The no-load protection circuit includes a full-bridge rectifier circuit D4, a third protection diode D3, and a fourth resistor R4 connected in series between the positive end VOP and the negative end VON of the voltage output. Two input ends of the full-bridge rectifier circuit D4 are respectively connected to the two ends of the low-voltage side of the transformer. The two output ends of the full-bridge rectifier circuit are connected to the positive end VOP and the negative end VON of the voltage output. The positive end VOP and the negative end VON of the voltage output are further connected in parallel with a power tube M and an energy storage capacitor C3. The base of the power tube M is connected to the common end of the third protection diode D3 and the fourth resistor R4. Figure 1

[0023] ​​The AC power outputted from the low voltage side of the transformer is shaped by the full-bridge rectifier circuit D4 composed of four diodes, the power tube M adopts NPN triode, and the base potential of the power tube M is pulled down by the fourth resistor R4 in normal operation, so the power tube M cannot be turned on, when the electric load is low and close to no load, the current decreases, the output power of the transformer T is generally unchanged or decreases nonlinearly, but the voltage between the positive voltage output VOP and the negative voltage output VON increases, when the voltage reaches the breakdown threshold set by the third protection diode D3 and the fourth resistor R4, the third protection diode D3 is broken down, the voltage on the fourth resistor R4 rises, the base potential of the power tube M rises, the power tube M is turned on, and the load current is increased, so that the output voltage is prevented from rising due to the too low load.

[0024] When the input part of the power taking circuit has abnormal current, the output part will also have large current outputted by the transformer, Figure 1 As shown in the specific embodiment, the protection action of the input part can be directly applied to the no-load protection circuit of the output part through the coupling circuit, the abnormality of the input part is reacted by the no-load protection circuit, and the coupling circuit includes the optocoupler G, the input end of the optocoupler G is connected to the control end of the bleeder tube, and the two output ends of the optocoupler G are respectively connected to the positive end and the negative end of the third protection diode D3.

[0025] When the input part has high voltage, the light emitting device of the optocoupler G is driven to emit light when the first protection diode D1 or the second protection diode D2 is turned on, so that the two output ends of the optocoupler are turned on, the third protection diode D3 is short-circuited, the base of the power tube M is connected to the positive voltage output VOP, so that the power tube M is turned on, and the large current possibly generated in the bleeder output stage is protected synchronously by the existing protection circuits of the input stage and the output stage through the coupling circuit. Figure 1 In the specific embodiment, the sixth resistor R6 can be connected in series with the input end of the optocoupler G, so as to limit the large current possibly generated in the optocoupler.

[0026] As Figure 2 A principle block diagram of one specific embodiment of the capacitor power taking circuit for the primary and secondary fusion pole-mounted circuit breaker is shown in the specific embodiment of the utility model, which comprises a current bleeder path connected to the voltage input end, a bleeder control circuit, a no-load protection circuit connected to the positive voltage output end, and a coupling circuit connected between the bleeder control circuit and the no-load protection circuit.

[0027] The capacitor electricity taking circuit for the primary and secondary fused circuit breaker can realize the ground protection and overvoltage protection of the input end simultaneously by the current discharge path, and can realize the synchronous protection when the input end is abnormal by the no-load protection circuit of the output end.

[0028] The foregoing is the various preferred embodiments of the utility model, and the preferred embodiments in the various preferred embodiments can be arbitrarily stacked and combined if not obviously self-contradictory or with a certain preferred embodiment as a premise, the embodiments and the specific parameters in the embodiments are only for clearly describing the utility model verification process of the utility model person, and are not used to limit the patent protection scope of the utility model, and the patent protection scope of the utility model is still subject to the right claim, and equivalent structural changes made by using the content of the specification and drawings of the utility model should also be included in the protection scope of the utility model.

Claims

1. A capacitor-driven power supply circuit for a primary and secondary integrated pole-mounted circuit breaker, comprising a first power supply capacitor (C1) and a second power supply capacitor (C2) connected in series, and a transformer (T) connected in parallel through the high-voltage side and the second power supply capacitor, wherein the low-voltage side of the transformer is connected to a positive voltage output terminal (VOP) and a negative voltage output terminal (VON), characterized in that, The first end of the second power taking capacitor (C2) connected with the first power taking capacitor (C1) is connected with a current discharge path, and a discharge tube (TV) is arranged on the current discharge path. The control end of the discharge tube is connected with a discharge control circuit. The discharge control circuit comprises a first protection diode (D1). The second end of the second power taking capacitor (C2) is connected with the negative electrode of the first protection diode (D1). The positive electrode of the first protection diode (D1) is connected with the control end of the discharge tube (TV).

2. The capacitor power deriving circuit for a secondary fuse-pole circuit breaker according to claim 1, wherein The discharge tube (TV) is a plurality of discharge tubes in series connection. An inductor (L) is connected in series between the second power taking capacitor (C2) and the first discharge tube.

3. The capacitive power derivation circuit for a secondary fuse-pole circuit breaker of claim 1, wherein, The discharge control circuit further comprises a second protection diode (D2). The common end of the first power taking capacitor (C1) and the second power taking capacitor (C2) is connected with the negative electrode of the second protection diode (D2). The positive electrode of the second protection diode (D2) is connected with the control end of the discharge tube (TV).

4. The capacitor power deriving circuit for a secondary fuse-pole circuit breaker of claim 3 wherein, The discharge tube (TV) is a BT131-800D. The first protection diode (D1) and the second protection diode (D2) are both p6KE520CA.

5. The capacitor power deriving circuit for a secondary fuse cutout of claim 3, wherein, The first protection diode (D1) and the second protection diode (D2) are connected with a resistor between the resistor and the control end of the discharge tube (TV).

6. The capacitive power derivation circuit for a secondary fuse-pole circuit breaker of claim 1, wherein, The capacitor power taking circuit further comprises a no-load protection circuit arranged on the positive end of the voltage output. The no-load protection circuit comprises a full-bridge rectifier circuit (D4), a third protection diode (D3) and a fourth resistor (R4) connected in series between the positive end (VOP) and the negative end (VON) of the voltage output. Two input ends of the full-bridge rectifier circuit are respectively connected with two ends of the low-voltage side of the transformer. Two output ends of the full-bridge rectifier circuit are connected with the positive end (VOP) and the negative end (VON) of the voltage output. A power tube (M) and an energy storage capacitor (C3) are connected in parallel between the positive end (VOP) and the negative end (VON) of the voltage output. The base of the power tube (M) is connected with the common end of the third protection diode (D3) and the fourth resistor (R4).

7. The capacitor power deriving circuit for a secondary fuse cutout of claim 6, wherein, The coupling circuit further comprises an optical coupler (G). The input end of the optical coupler (G) is connected with the control end of the discharge tube. Two output ends of the optical coupler (G) are respectively connected with the positive end and the negative end of the third protection diode (D3).

8. The capacitor power deriving circuit for a secondary fuse cutout of claim 7, wherein, A sixth resistor (R6) is connected in series on the input end of the optical coupler (G).

Images