CN110690688A - Lightning arrester protection device and lightning arrester protection method - Google Patents

Lightning arrester protection device and lightning arrester protection method Download PDF

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Publication number
CN110690688A
CN110690688A CN201910790254.0A CN201910790254A CN110690688A CN 110690688 A CN110690688 A CN 110690688A CN 201910790254 A CN201910790254 A CN 201910790254A CN 110690688 A CN110690688 A CN 110690688A
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lightning arrester
phase
distribution network
series
circuit
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李清远
廖天阳
吴贝
刘蔚然
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Shaoguan Bai Rui Energy Saving Technology Co Ltd
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Shaoguan Bai Rui Energy Saving Technology Co Ltd
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H9/00—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection
    • H02H9/005—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection avoiding undesired transient conditions
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H9/00—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection
    • H02H9/04—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection responsive to excess voltage
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/18—Arrangements for adjusting, eliminating or compensating reactive power in networks
    • H02J3/1821—Arrangements for adjusting, eliminating or compensating reactive power in networks using shunt compensators
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
    • Y02E40/30—Reactive power compensation

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  • Power Engineering (AREA)
  • Emergency Protection Circuit Devices (AREA)

Abstract

The invention provides a lightning arrester protection device, which comprises an auxiliary lightning arrester group, wherein the auxiliary lightning arrester group is a three-phase circuit, each phase of circuit is a filter capacitor and an auxiliary lightning arrester which are connected in series, and the filter capacitor of each phase of circuit is respectively connected with a corresponding phase of circuit in a three-phase power distribution network bus; the auxiliary lightning arrester of each phase circuit is grounded after the tail ends of the phase branches are connected in a star shape together; the rated voltage values of the auxiliary lightning arresters are the same and are lower than the conduction voltage of the bus lightning arrester connected in series with the power distribution network bus. Compared with the prior art, the auxiliary lightning arrester in the scheme conducts and releases overvoltage in advance, provides protection for all isopotential bus lightning arresters on the power distribution network bus, and avoids explosion of the bus lightning arresters. Meanwhile, the filter capacitor limits the current flowing through the auxiliary lightning arrester, the auxiliary lightning arrester is prevented from being damaged, the auxiliary lightning arrester can be further isolated from the power distribution network when the auxiliary lightning arrester is exploded, and the normal work of the power distribution network is not influenced.

Description

Lightning arrester protection device and lightning arrester protection method
Technical Field
The invention relates to the field of power utilization safety of a power distribution network, in particular to a protection device and a protection method for an arrester in the power distribution network.
Background
The existing power distribution network consists of a power station, a transformer substation and a user side, wherein the power station, the transformer substation and the user side are connected through buses for power transmission. The main problem faced in the operation of the existing power distribution network is that the power distribution network is easy to be struck by lightning due to the long-distance arrangement of the power transmission device, and the power equipment is damaged or even the life and property safety of surrounding people is harmed.
Referring to fig. 1, fig. 1 is a schematic view of a connection relationship between a bus and a bus arrester in a power distribution network in the prior art. In the prior art, in order to avoid lightning strike to damage the power equipment on the bus, one or more groups of bus lightning arresters 10 are usually connected to the bus, and the groups of lightning arresters are equipotential and have the same source. The bus arrester group 10 comprises three bus arresters F1 with the same conduction voltage, the head ends of the three bus arresters F1 are respectively connected with a three-phase circuit of a bus, and the tail ends of the three-phase bus arresters F1 are connected in a star shape and then grounded. When a certain phase bus circuit of the power distribution network is struck by lightning, the bus lightning arrester F1 on the phase bus circuit is conducted to the ground, the overvoltage is discharged, and the damage of the overvoltage to other power equipment on the circuit is avoided.
However, the existing arrester has limited thermal capacity, and the bus arrester is easy to generate dangerous situations of malfunction conduction, single long-time conduction or multiple conduction in a short time under the influence of harmonic waves with complex frequency spectrum and severe fluctuating voltage in a power distribution network, so that the heat of the bus arrester exceeds tolerance, single-phase grounding of a bus is caused, or grounding alarm, overcurrent protection tripping and even quick-break action of a relay protection device are triggered due to overcurrent; in severe cases, the lightning arrester will explode due to too high heat, causing short circuit between phases. Therefore, the lack of a circuit structure for protecting the lightning arrester is a big drawback of the existing power distribution network circuit.
Disclosure of Invention
The invention provides a lightning arrester protection device, which comprises an auxiliary lightning arrester group, wherein the auxiliary lightning arrester group is a three-phase circuit, each phase of circuit is a filter capacitor and an auxiliary lightning arrester which are connected in series, and the filter capacitor of each phase of circuit is respectively connected with a corresponding phase of circuit in a three-phase power distribution network bus; the auxiliary lightning arrester of each phase circuit is grounded after the tail ends of the phase branches are connected in a star shape together; the rated voltage values of the auxiliary lightning arresters are the same and are lower than the conduction voltage of the bus lightning arrester connected in series with the power distribution network bus.
Compared with the prior art, this scheme is through making supplementary arrester switch on the overvoltage of releasing in advance, can protect all isopotential bus arresters on the distribution network bus, avoids the bus arrester to switch on repeatedly in the short time or the single switches on for a long time and leads to distribution network system trouble or arrester self high temperature and take place to explode and split. Meanwhile, the filter capacitor limits the current flowing through the auxiliary lightning arrester, the auxiliary lightning arrester is prevented from being damaged, the auxiliary lightning arrester can be further isolated from the power distribution network when the auxiliary lightning arrester is exploded, and the normal work of the power distribution network is not influenced.
Furthermore, the conducting voltage value of the auxiliary lightning arrester is selected between the rated line voltage of each phase of power transmission line of the power distribution network and the rated phase voltage of each phase of power transmission line of the power distribution network.
Furthermore, the auxiliary lightning arrester group also comprises an auxiliary lightning arrester, and each auxiliary lightning arrester in the three-phase circuit of the auxiliary lightning arrester group is grounded through one auxiliary lightning arrester after the tail ends of the branch circuits of each phase are connected in a star shape together.
Further, the lightning arrester protection device also comprises a reactive power compensation device, wherein the reactive power compensation device is a three-phase circuit and is respectively connected with a three-phase bus of the power distribution network; and each filter capacitor of the auxiliary lightning arrester group is respectively connected with the three-phase circuit of the reactive power compensation device. In this scheme arrester protection device not only can protect the arrester, can also provide reactive compensation to the distribution network.
Furthermore, each phase circuit of the reactive power compensation device comprises a series reactor, a fuse and a capacitor which are sequentially connected in series, and a discharge coil which is connected with the fuse and the capacitor in parallel; and a filter capacitor on each phase circuit of the auxiliary lightning arrester group is respectively connected between a current transformer and a series reactor in one phase circuit of the reactive power compensation device.
Furthermore, the reactive power compensation device comprises a zero sequence current transformer, and each phase circuit of the zero sequence current transformer comprises a high-pass filter resistor, a series reactor and a compensation capacitor which are connected in series; the series reactor of each phase circuit of the reactive power compensation device is respectively connected in series between the filter capacitor and the auxiliary lightning arrester in the three-phase circuit of the auxiliary lightning arrester group, and the compensation capacitors of the reactive power compensation device are connected in a star shape together at the tail ends of the branch circuits where the compensation capacitors are located; the zero sequence current transformer is connected in series between a filter capacitor and a series reactor on the three-phase circuit; one end of a high-pass filter resistor of each phase circuit of the reactive power compensation device is respectively connected in series between a zero sequence current transformer and a filter capacitor on the phase circuit, and the other end of the high-pass filter resistor is connected with the tail end of the branch circuit in a common star shape. The circuit structure in the scheme can form a C-type heterogeneous high-pass filter, multiple high-frequency harmonics can be filtered, and the filter is insensitive to the harmonics and not easy to overload and damage. Each phase of lightning arrester protection circuit can further provide an overvoltage discharge channel through a grounding resistor, so that harmonic overvoltage damage is avoided. Meanwhile, harmonic signals can be led out from the star-connected filter resistors to be used for harmonic analysis of a subsequent circuit.
Furthermore, the reactive power compensation device comprises a zero sequence current transformer and a grounding resistor, and each phase circuit of the reactive power compensation device comprises a high-pass filter resistor, a series reactor and a compensation capacitor which are connected in series; the series reactor of each phase circuit of the reactive power compensation device is respectively connected in series between the filter capacitor and the auxiliary lightning arrester in the three-phase circuit of the auxiliary lightning arrester group, and the compensation capacitors of each phase circuit of the reactive power compensation device are connected in a star shape at the tail ends of the branch circuits where the compensation capacitors are located; the zero sequence current transformer is connected in series between a filter capacitor and a series reactor on the three-phase circuit; one end of a high-pass filter resistor of each phase circuit of the reactive power compensation device is respectively connected between a zero sequence current transformer and a filter capacitor on the phase circuit in series, and the other end of the high-pass filter resistor is connected with the tail end of the branch circuit in a common star shape and then grounded through a grounding resistor.
Furthermore, the arrester protection device also comprises a harmonic loss energy recovery unit, wherein the harmonic loss energy recovery unit comprises a rectifier, a controller, a current divider, a voltage-regulating silicon chain and a non-return diode, wherein the current divider, the voltage-regulating silicon chain and the non-return diode are sequentially connected in series with the anode output end of the rectifier; three input ends of the rectifier are respectively connected in series on a branch circuit through which harmonic current flows in a three-phase circuit of the reactive power compensation device; the controller is respectively connected with the shunt and the voltage regulating silicon chain, and receives input signals of the shunt and outputs electric signals to the voltage regulating silicon chain to regulate the output voltage of the anode of the rectifier. The scheme realizes the transfer and recovery of harmonic loss energy in the power distribution network.
The invention also provides a method for protecting the lightning arrester, wherein the auxiliary lightning arrester group is a three-phase circuit, and each phase of circuit comprises a filter capacitor and an auxiliary lightning arrester which are connected in series; the method comprises the following steps that a reactive power compensation device is arranged on a power distribution network bus, the reactive power compensation device is a three-phase circuit which is respectively connected with the three-phase bus of the power distribution network, the reactive power compensation device comprises a zero sequence current transformer, and each phase circuit of the reactive power compensation device comprises a high-pass filter resistor, a series reactor and a compensation capacitor which are connected in series; the series reactor of each phase circuit of the reactive power compensation device is respectively connected in series between the filter capacitor and the auxiliary lightning arrester in the three-phase circuit of the auxiliary lightning arrester group, and the compensation capacitors of the reactive power compensation device are connected in a star shape together at the tail ends of the branch circuits where the compensation capacitors are located; the zero sequence current transformer is connected in series between a filter capacitor and a series reactor on a three-phase circuit of the reactive power compensation device; one end of a high-pass filter resistor of each phase circuit of the reactive power compensation device is respectively connected between a zero sequence current transformer and a filter capacitor on the phase circuit in series, and the other end of the high-pass filter resistor is connected with the tail end of the branch circuit in a common star shape and then grounded through a grounding resistor; and setting the conduction voltage of each auxiliary lightning arrester to be lower than the conduction voltage of the bus lightning arrester.
Furthermore, the rated voltage value of the auxiliary lightning arrester is set to be between the line voltage of each phase of power transmission line of the power distribution network and the phase voltage of each phase of power transmission line of the power distribution network;
further, setting the reactance value of the compensation capacitor to be equal to the reactance value of the series reactor;
further, setting the capacitive reactance of the filter capacitor
Figure BDA0002179339830000031
Wherein U is said power line voltage, ILRated current of the series reactor;
further, the filter resistor R is setHAnd a ground resistance RE2Satisfies 0.35Ie×(RH+3RE2)≤UrWherein U isrTo assist the lightning arrester in conducting voltage, IeIs the rated current of the filter capacitor.
Drawings
FIG. 1 is a schematic diagram of a connection relationship between a bus bar and a bus bar arrester of a power distribution network in the prior art;
fig. 2 is a circuit diagram of a lightning arrester protection device according to embodiment 1 of the present invention connected to a bus of a distribution network;
fig. 3 is a circuit diagram of a lightning arrester protection device according to embodiment 2 of the present invention connected to a bus bar of a distribution network;
fig. 4 is a circuit diagram of a lightning arrester protection device according to embodiment 3 of the present invention connected to a bus bar of a distribution network;
fig. 5 is a circuit diagram of an arrester protection device according to embodiment 4 of the present invention connected to a distribution network bus;
fig. 6 is a schematic structural diagram of positive and negative sequence component impedances of harmonic waves when the distribution network is connected to the lightning arrester protection device in embodiment 4 of the present invention;
fig. 7 is a schematic diagram of a harmonic zero-sequence component impedance structure when a power distribution network is connected to a lightning arrester protection device in embodiment 4 of the present invention;
fig. 8 is a schematic structural diagram of positive and negative sequence component impedances of harmonic waves when the power distribution network is connected to the conventional reactive power compensation device in embodiment 4 of the present invention;
fig. 9 is a schematic structural diagram of a harmonic zero-sequence component impedance when the power distribution network is connected to the existing reactive power compensation device in embodiment 4 of the present invention;
fig. 10 is a harmonic positive-negative sequence impedance curve diagram when the distribution network is connected to the conventional reactive power compensation device in embodiment 4 of the present invention;
fig. 11 is a positive-negative sequence impedance curve diagram of a power distribution network to which 1 set of lightning arrester protection devices are connected in embodiment 4 of the present invention;
fig. 12 is a positive-negative sequence impedance curve diagram of a power distribution network connected with 5 sets of lightning arrester protection devices in embodiment 4 of the present invention;
fig. 13 is a comparison graph of the positive and negative sequence harmonic impedance curves of the distribution network connected to the conventional reactive power compensation device and the 1-5 sets of lightning arrester protection devices in the embodiment 4 of the present invention;
fig. 14 is a comparison graph of harmonic zero-sequence impedance curves of the power distribution network connected with the existing reactive power compensation device and the 1-5 sets of lightning arrester protection devices in the embodiment 4 of the invention;
fig. 15 is a schematic circuit diagram of an arrester protection device according to embodiment 5 of the present invention.
Fig. 16 is a schematic circuit diagram of a harmonic loss energy recovery unit in embodiment 5 of the present invention.
Detailed Description
The invention aims to provide a lightning arrester protection device which can protect all isopotential bus lightning arresters on a power distribution network bus. Firstly, researching a scheme of adopting the lightning arrester as the lightning arrester to protect other lightning arresters, and obtaining a structure of adding a group of auxiliary lightning arresters in a power distribution network to protect other bus lightning arresters; the design is further combined with the reactive power compensation device of the auxiliary lightning arrester group and the power distribution network, the effect that the bus lightning arrester group is protected and reactive power compensation can be provided for the power distribution network is achieved, and therefore the stability and the high efficiency of power distribution network energy transmission are improved.
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.
Example 1
In the distribution network, one or more groups of bus arrester groups 10 connected with the buses of the distribution network are arranged, the conduction voltage of each arrester F1 in each group of bus arrester groups 10 is the same, and the groups of arrester groups are equal in potential and are homologous to each other. Referring to fig. 2, in the present embodiment, the lightning arrester protection device of the present invention is an auxiliary lightning arrester group 20. The auxiliary lightning arrester group 20 and the bus lightning arrester group 10 are respectively connected in series on a bus of a power distribution network, and are respectively grounded at the tail ends. Wherein, the auxiliary lightning arrester group 20 includes a three-phase circuit connected with a three-phase circuit of a bus, each phase of the circuit structure of the auxiliary lightning arrester group 20 is the same, and it includes a filter capacitor C connected in seriesHAnd an auxiliary arrester F2. Wherein the filter capacitor C of each phase circuitHAnd the auxiliary lightning arresters F2 of each phase of circuit are connected with the ground after being connected in a star shape together. The rated voltage values of the auxiliary arresters F2 are the same and are lower than the conducting voltage of the bus arrester F1.
When the power distribution network normally works, the bus arrester F1 is not conducted with the auxiliary arrester F2. When the power distribution network is struck by lightning, if the instantaneous lightning overvoltage value is less than the conduction voltage of the bus arrester F1, the auxiliary arrester F2 conducts and discharges the overvoltage before the bus arrester F1 conducts. Due to the voltage clamping action of the auxiliary arrestor F2, the bus arrestor F1 will remain in a non-conductive state. When the lightning stroke overvoltage amplitude of the bus hitting is large and the bus arrester F1 is directly conducted, the auxiliary arrester F2 conducts the discharge voltage at the same time, so that the conduction time of the bus arrester F1 is shortened, the overvoltage energy absorbed by the bus arrester F1 is reduced, and the bus arrester is prevented from being overheated.
At the same time, the filter capacitor CHThe amplitude of the current flowing through the auxiliary lightning arrester F2 is limited, so that the heat generated when the auxiliary lightning arrester F2 is conducted is limited, and the auxiliary lightning arrester F2 is prevented from thermal breakdown and explosion. And even if the auxiliary arrester F2 bursts, the filter capacitor CHThe current limiting and isolating function of the auxiliary lightning arrester F2 can ensure that the fault of the auxiliary lightning arrester F2 does not affect the power distribution network.
The auxiliary arrester group 20 in this embodiment can protect all the isopotential bus arresters F1 connected to the power distribution network.
Example 2
Referring to fig. 3, this embodiment is a modification of embodiment 1, and in this embodiment, the circuit structure of the auxiliary arrester group 21 is substantially the same as that of the auxiliary arrester group 20 in embodiment 1, except that the auxiliary arresters F2 of each phase circuit of the auxiliary arrester group 21 are connected in a star shape and then grounded through an auxiliary arrester F2. In this embodiment, the rated voltage values of the auxiliary arresters F2 are all the same. In operation, the auxiliary arrester group 21 in this embodiment can also protect all the isopotential bus arresters F1 connected to the power distribution network by conducting and discharging overvoltage in advance.
Example 3
In the distribution network, one or more groups of bus arrester groups 10 connected with the buses of the distribution network are arranged, the conduction voltage of each arrester F1 in each group of bus arrester groups 10 is the same, and the groups of arrester groups are equal in potential and are homologous to each other. Meanwhile, in order to improve the power factor of the power distribution network, reduce the energy loss in the power transmission process and ensure the energy transmission efficiency of the power distribution network, the power distribution network is usually connected with a reactive power compensation device in the power distribution network.
In this embodiment, arrester protection device has combined the reactive power compensator who inserts the distribution network, has arrester protect function and reactive power compensation function simultaneously. Referring to fig. 4, the arrester protection device of the present embodiment includes an auxiliary arrester group 21 and a reactive power compensation device 30. The reactive power compensation device 30 is a three-phase circuit, and each phase of circuit comprises a switching element KM, a current transformer 1TA, a series reactor L, a fuse FU, a capacitor C and a discharge coil TV connected in parallel with the fuse FU and the capacitor C. And the three-phase circuit of the reactive power compensation device 30 is connected with a three-phase bus circuit through the switching element KM.
The circuit configuration of the auxiliary arrestor group 21 is the same as that of the auxiliary arrestor group in embodiment 2, and each phase circuit thereofFilter capacitor C ofHThe auxiliary lightning arresters F2 of each phase circuit of the auxiliary lightning arrester group 21 are connected in a common star connection and then grounded through an auxiliary lightning arrester F2.
In a modification of this embodiment, the reactive power compensation device 30 may further include a branch arrester group including three branch arresters F3, and each of the branch arresters F3 is connected between the current transformer 1TA and the series reactor L on the three-phase circuit of the reactive power compensation device. The conducting voltage of each of the distributing arresters F3 is the same as the conducting voltage of the bus arrester F1 in the bus arrester group 10.
When the system works, the series reactor L carries out reactive compensation on the power distribution network. When the power distribution network normally works, the bus arrester F1, the branch arrester F3 and the auxiliary arrester F2 are not conducted. When the distribution network is struck by lightning, if the instantaneous lightning overvoltage value is less than the conduction voltage of the bus lightning arrester F1 and the branching lightning arrester F3, the auxiliary lightning arrester F2 conducts with the branching lightning arrester F3 before the bus lightning arrester F1 discharges the overvoltage. Due to the voltage clamping effect of the auxiliary arrestor F2, the bus arrestor F1 and the branch arrestor F3 will remain in a non-conductive state. When the lightning stroke overvoltage amplitude of the bus hitting is large and the bus lightning arrester F1 is directly conducted with the branching lightning arrester F3, the auxiliary lightning arrester F2 conducts the leakage voltage at the same time, so that the conduction time of the bus lightning arrester F1 and the branching lightning arrester F3 is shortened, the absorbed overvoltage energy is reduced, and the bus lightning arrester is prevented from being overheated.
Example 4
The circuit configuration of the arrester protection device of the present embodiment is substantially the same as that of the arrester protection device in embodiment 3, except that the present embodiment provides another reactive power compensation device 40 with respect to embodiment 3. Referring to fig. 5, the arrester protection device of the present embodiment is a three-phase circuit, and includes an auxiliary arrester group 21 and a reactive power compensation device 40.
The reactive power compensation device 40 is a three-phase circuit, and in each phase circuit, one side of a static contact of an isolating switch QS is dividedRespectively connected with a phase circuit of the bus, one side of a moving contact of the bus is connected with the current transformers 1TA and 2TA in series and then connected with a filter capacitor C in a phase circuit of the auxiliary lightning arrester group 21HAnd (4) connecting. The current transformers 1TA and 2TA each include a primary coil and a secondary coil, and the primary coil of the current transformer is connected in series to the phase circuit isolating switch QS and the filter capacitor CHMeanwhile, the secondary coil of the current transformer induces the current of the primary coil and outputs a signal, and the signal can be used for measuring the current of a current signal or providing a current protection signal.
The reactive power compensation device 40 further comprises a zero sequence current transformer LHA ground resistor RE2And a discharge coil TV, and each phase circuit of the reactive power compensation device 40 includes a high pass filter resistor RHFuse FU and series reactor L connected in series1And a compensation capacitor C1(ii) a Series reactor L of each phase circuit of reactive power compensation device1The filter capacitors C are respectively connected in series in the three-phase circuit of the auxiliary lightning arrester group 21HAnd the auxiliary lightning arrester F2, and the compensation capacitor C of each phase circuit1The tail ends of the branches are connected in a star shape; the zero sequence current transformer LHA filter capacitor C connected in series with the three-phase circuit of the reactive power compensation device 40HAnd series reactor L1To (c) to (d); high-pass filter resistor R of each phase circuit of reactive power compensation device 40HOne end of the zero sequence current transformer L is respectively connected with the phase circuit in seriesHAnd a filter capacitor CHThe other end of the branch is connected with the tail end of the branch in a common star shape and then passes through a grounding resistor RE2And (4) grounding. Three ends a, b and C of the primary coil of the discharge coil TV are respectively connected to current transformers 1TA, 2TA and a filter capacitor C on the three-phase circuit of the reactive power compensation device 40 through a fuse FUHIn the meantime. The secondary coil of the discharge coil TV is connected to the filter capacitor C on the three-phase circuit of the reactive power compensation device 40 through the ka, kb and kc endsHAnd an auxiliary lightning arrester F2, and a voltage V is passed through the secondary coilS0The output end and the high-pass filter resistor RHAre connected with the star-shaped connection points. The discharge coil TV is capable of bleeder filteringCapacitor CHOf the charge remaining in the cell.
The reactive power compensation device 40 further comprises a first electrified display group and a second electrified display group, each electrified display group comprises a three-phase circuit, each phase of circuit has the same structure and comprises a capacitor and an electrified display which are connected in series, and the capacitor of each phase of circuit is grounded after being connected in a common star shape at the tail end of the branch where the capacitor is located. The first display group comprises three same electrified displays SQ1, and the capacitor of each phase circuit is respectively connected between an isolating switch QS and the current transformers 1TA and 2TA in the three-phase circuit. The second display group comprises three same electrified displays SQ2, and the capacitance of each phase circuit is respectively connected with current transformers 1TA and 2TA and a filter capacitor C in the three-phase circuitHIn the meantime. The live display is lighted under the condition of voltage, and provides a high-voltage live indication for an engineer.
In a modification of this embodiment, the installation position of the bus arrester group 10 is modified, and specifically, the reactive power compensation device 40 may further include a branch arrester group 11 including three branch arresters F3, where each branch arrester F3 is respectively connected to the current transformers 1TA and 2TA and the filter capacitor C on the three-phase circuit of the reactive power compensation device 40HIn the meantime. The conducting voltage of each of the distributing arresters F3 is the same as the conducting voltage of the bus arrester F1 in the bus arrester group 10. Because the working principle and the process of each branching arrester in the branching arrester group 11 are the same as those of the bus arrester, the branching arrester group can also achieve the overvoltage protection function in a power distribution network. The following description is made of the principle of the busbar arrester, and the description is also applicable to the branching arrester.
When the power distribution network normally works, each capacitor and each reactor in the lightning arrester protection device perform reactive compensation on the power distribution network, and meanwhile, each filter capacitor CHFilter resistor RHEarth resistance RE2Series reactor L1And a compensation capacitor C1And the discharge coil TV forms a plurality of filters for filtering the harmonic waves of the power distribution network.
When the bus bar is in lightning overvoltage, the L reactance is used1High impedance and filter capacitor C for high frequency signalHLow impedance to surge signal and flows through filter capacitor CHThe surge current such as thunder and lightning firstly flows to the filter resistor RE2The arrester F2 at the front end, the auxiliary arrester F2 reach the turn-on voltage and turn on prior to the bus arrester F1, bleed the overvoltage and clamp the voltage to ground of the phase circuit. When the bus arrester F1 is directly conducted due to the fact that the overvoltage amplitude entering the bus is large, the auxiliary arrester F2 conducts the discharge voltage at the same time, and overheating of the bus arrester is avoided.
The working principle of the arrester protection device of this embodiment 4 is explained as follows:
(1) the principle of protecting the lightning arrester:
1) protection of auxiliary lightning arrester F2 by using capacitance current-limiting method
Filter capacitor C in each phase circuit of lightning arrester protection deviceHThe maximum fundamental current magnitude flowing through the auxiliary arrester F2 is limited. At the moment, the current fundamental component does not exceed the current fundamental component when the auxiliary lightning arrester F2 is conducted
Figure BDA0002179339830000081
Is much less than the nominal discharge current of the lightning arrester, so that the auxiliary lightning arrester F2 is not easy to generate thermal breakdown accidents when being conducted.
At the same time, a filter capacitor CHThe auxiliary lightning arrester F2 is isolated in a current limiting manner, so that the auxiliary lightning arrester F2 is ensured not to cause the faults of single-phase grounding, overcurrent or interphase short circuit and the like of a power distribution network circuit in abnormal states such as overlong conduction time, explosion and the like, namely the faults of the auxiliary lightning arrester are ensured not to influence the normal operation of the system.
2) Protection bus arrester F1 principle:
the filter circuit formed by the circuit elements of the lightning arrester protection device limits the n-th harmonic voltage amplitude which possibly appears in a power distribution network bus, and meanwhile, an auxiliary lightning arrester F2 with the conducting voltage smaller than the conducting voltage of the bus lightning arrester is arranged on each phase circuit of the lightning arrester protection device circuit, so that all the same-source equipotential bus lightning arresters on the power distribution network bus are protected.
In particular, the lightning protectionThe protector limits the n-th harmonic voltage value of the bus to
Figure BDA0002179339830000082
Wherein ZnIs the n-th harmonic impedance of the system, ZHAdding point harmonic impedance on the bus of the distribution network after the lightning arrester protection device is addednIs the nth harmonic current.
The rated voltage value of the auxiliary lightning arrester F2 is selected as follows:
rated voltage U of auxiliary lightning arrester F2rThe value range is between the rated line voltage of each phase of power transmission line of the power distribution network and the rated phase voltage of each phase of power transmission line of the power distribution network, and the value of the rated voltage of the auxiliary lightning arrester F2 is preferably 1/2 times of the conducting voltage of the bus lightning arrester.
At the same time, the auxiliary lightning arrester F2 in the ungrounded single-phase circuit reaches the nominal rated current I of the lightning arrester protection device at the current value flowing into the lightning arrester protection devicee(it can be calculated using a filter capacitor CHRated current of) to ensure that no misconduction occurs and that overvoltage generated by non-lightning does not trigger the arrester to conduct and release the voltage. Thus, the arrester F2 has a rated voltage UrFilter resistor RHAnd a ground resistance RE2The following condition is satisfied:
0.35Ie×(RH+3RE2)≤Ur。
(2) reactive compensation principle:
filter capacitor C in lightning arrester protection deviceHSeries reactor L1And a compensation capacitor C1And the reactive compensation is carried out on the power distribution network in a mutual matching way.
(3) The filtering principle is as follows:
the lightning arrester protection device filter capacitor CHFilter resistor RHEarth resistance RE2Series reactor L1And a compensation capacitor C1The lightning arrester protection device can filter and eliminate harmonic waves of the full passband harmonic waves by matching with each other to form various filters. Wherein the three-phase symmetrical circuit (filtering) of the lightning arrester protection deviceCapacitor CHFilter resistor RHEarth resistance RE2Series reactor L1And a compensation capacitor C1) The structure forms a C-type high-pass filter; each phase-to-ground loop forms a second-order high-pass filter; zero sequence current loop (Filter capacitor C)HFilter resistor RHEarth resistance RE2And discharge coil TV) forms a low-pass filter when matched to the ground impedance of the neutral ground loop of the external distribution network system.
The positive and negative sequence impedance parts of the equivalent harmonic impedance structure of the power distribution network refer to fig. 6 and fig. 7, which are respectively a schematic diagram of a positive and negative sequence component harmonic impedance structure and a schematic diagram of a zero sequence component harmonic impedance structure of a 10kV system when 1-5 sets of reactive compensation devices are connected to the power distribution network.
From fig. 6, the impedance formula of the positive and negative sequence components of the harmonic wave of the distribution network is changed by installing 1 set of the lightning arrester protection device in the distribution network:
Z1 n＝(1/Zsn+1/Zfzn+1/Zcen+1/ZHn)-1
2 sets of lightning arrester protection devices are arranged in the power distribution network, and then the impedance formula of the positive and negative sequence components of the harmonic wave of the power distribution network is shown as follows:
Z2 n＝(1/Zsn+1/Zfzn+1/Zcen+1/ZHn+1/ZHn)-1
the method comprises the following steps of arranging n sets of lightning arrester protection devices in a power distribution network, and then obtaining a power distribution network harmonic positive-negative sequence component impedance formula:
wherein, X in FIG. 6SShort-circuiting reactance, X, of the main transformerZBIs the impedance of a grounded transformer, XF1Is generator equivalent impedance, CeFor line-to-line capacitance, XfzIs a load impedance, InIs an n-th harmonic current, CHIs a filter capacitor, L1Is a fundamental branch current, C1A compensation capacitor for the fundamental wave branch, a discharge coil for TV,in order to add 1-5 sets of the lightning arrester protection device and then add n-th harmonic impedance,
Figure RE-GDA0002291911700000095
is the system nth harmonic impedance.
As can be seen from fig. 7, the impedance formula of the harmonic zero-sequence component of the grounding loop of the power distribution network when 1 set of the lightning arrester protection device is installed is as follows:
Figure RE-GDA0002291911700000096
when 2 sets of lightning arrester protection devices are installed, a system grounding circuit harmonic zero-sequence component impedance formula is as follows:
Figure RE-GDA0002291911700000097
when n sets of lightning arrester protection devices are installed, a system grounding circuit harmonic zero-sequence component impedance formula is as follows:
Figure RE-GDA0002291911700000098
wherein R in FIG. 7E1Is a neutral point grounding resistor,Zero sequence reactance, C for grounding transformere1-Ce3For line-to-ground capacitance, In0Is the zero-sequence component of n-th harmonic current,Zero sequence reactance, R for arc suppression coilHIs a high-pass filter resistor, UY0Is RHStar connection point displacement voltage, RE2Is a ground resistor for limiting the current of the branch.
For comparison with the impedance structure of the prior art, please refer to fig. 8 and fig. 9, which are schematic diagrams of the positive-sequence component harmonic impedance structure and the negative-sequence component harmonic impedance structure of the 10kV system when the reactive power compensation device of the prior art is connected to the power distribution network, respectively.
As can be seen from fig. 8, the impedance formula of the positive and negative sequence components of the harmonic when the reactive power compensation device of the prior art is connected to the power distribution network:
x in FIG. 8SShort-circuiting reactance, X, of the main transformerZBIs the impedance of a grounded transformer, XF1Is generator equivalent impedance, CeFor line-to-line capacitance, XfzIs a load impedance, InIs the nth harmonic current.
From fig. 9, it can be obtained that the reactive power compensation device of the prior art is connected to the power distribution network, and the harmonic zero sequence impedance formula of the power distribution network when the neutral point resistor is grounded (neglecting the leakage reactance Z of the transformer)BL)：
R in FIG. 9E1Is a neutral point grounding resistor,Zero sequence reactance, C for grounding transformere1-Ce3For line-to-ground capacitance, In0Is the zero-sequence component of the n-th harmonic current.
Compared with the prior art and the harmonic impedance formula of the lightning arrester protection device, the harmonic impedance fundamental wave impedance of the power distribution network is small, and the generated overvoltage is smaller compared with the conventional reactive power compensation device.
Referring to fig. 10-13, to illustrate the impedance of the lightning arrester protection device at each harmonic frequency after the circuit is configured according to the above formula, and comparing with the prior art, fig. 10-13 shows positive and negative sequence impedance curves when the existing reactive power compensation device is added to the distribution network and when 1 to 5 sets of the lightning arrester protection device are added to the distribution network respectively. In fig. 10-13, the horizontal axes all represent the harmonic frequency, the vertical axes all represent the positive and negative sequence components of the harmonic impedance of the distribution network, points a-E in each figure have the same meaning, and points a-E sequentially represent the impedance peak points of the positive and negative sequence impedance components of the harmonic impedance of the distribution network when the reactive power compensation device in the prior art and 1-5 sets of the arrester protection device in the embodiment are respectively connected to the distribution network.
For the positive and negative sequence impedance of the power distribution network, when the reactive power compensation device in the prior art is connected to the power distribution network, the positive and negative sequence impedance curve of the power distribution network is steep, and the impedance peak value reaches about 1074 omega, and when one set of the lightning arrester protection device is connected to the power distribution network, the harmonic positive and negative sequence component impedance curve of the power distribution network is smoother, and the impedance peak value is greatly reduced to 185 omega. Further, when 2-5 sets of lightning arrester protection devices are additionally arranged in the power distribution network, the positive and negative sequence curves of the power distribution network are smoother, and the impedance peak value is further reduced. The positive and negative sequence impedance values under the harmonic frequency are in direct proportion to the overvoltage of the corresponding harmonic frequency, and the phenomena prove that compared with the conventional reactive power compensation device, the lightning arrester protection device can have a better suppression effect on the harmonic overvoltage of each frequency under the full-pass band, and the number of the lightning arrester protection devices connected into a power distribution network is increased, so that the suppression effect on the harmonic overvoltage can be enhanced.
Similarly, please refer to fig. 14 again, fig. 14 is a comparison graph of a harmonic zero-sequence impedance curve of the existing reactive power compensation device connected to the power distribution network and the lightning arrester protection device connected to 1 to 5 sets of lightning arrester in embodiment 4 of the present invention, wherein a horizontal axis represents a harmonic frequency, a vertical axis represents a zero-sequence component of the harmonic impedance of the power distribution network, and vertical axis values of points R-W are the harmonic impedance zero-sequence component impedance values of the power distribution network when the existing reactive power compensation device and the lightning arrester protection device of 1 to 5 sets of this embodiment are connected to the power distribution network, respectively. Compared with a power distribution network connected with a reactive power compensation device in the prior art, after the lightning arrester protection device 1 is additionally arranged in the power distribution network, the peak value of the harmonic zero-sequence component impedance curve of the power distribution network is relatively reduced, and the peak value of the impedance curve of the power distribution network is increased along with the increase of the number of the lightning arrester protection devices. The above phenomena prove that compared with the existing reactive power compensation device, the lightning arrester protection device can have good suppression effect on zero sequence overvoltage, and the number of the lightning arrester protection devices connected into the power distribution network is increased, so that the suppression effect on the zero sequence overvoltage can be enhanced
In conclusion, the lightning arrester protection devices can effectively reduce the harmonic positive and negative sequence component impedance and the zero sequence component impedance of the power distribution network after being connected to the power distribution network, and the number of the lightning arrester protection devices connected to the power distribution network is increased, so that the harmonic overvoltage frequency points of the power distribution network can be better inhibited, the possibility of generating the harmonic overvoltage of the power distribution network is eliminated, and the harmonic overvoltage is prevented from damaging power equipment in the power distribution network.
(4) The principle of providing multiple bleed channels for overvoltages of different magnitudes in a power distribution network:
as shown in fig. 5, a filter capacitor CHFilter resistor RHAnd a ground resistance RE2Forming a main zero sequence channel and discharging higher-frequency subharmonic overvoltage; discharge coil TV and ground resistance RE2Forming an auxiliary zero sequence channel and releasing low-frequency subharmonic overvoltage; filter capacitor CHAnd the auxiliary lightning arrester F2 or the bus lightning arrester F1 form a surge overvoltage (thunder) double-discharging channel respectively.
(5) The principle of shunting fundamental current, harmonic current and impact current in a power distribution network is as follows:
as shown in fig. 5, if the series reactor reactance and the compensation capacitor reactance of the lightning arrester protection device are set to satisfy XL1＝XC1Then series reactor L1And a compensation capacitor C1The fundamental wave impedance of the formed fundamental current branch is zero, and the current flows through a filter capacitor CHThe current (including fundamental current, harmonic current and surge current) realizes the shunting:
in the harmonic current, the positive and negative sequence components of the high-frequency harmonic current are mainly composed of a filter resistor RHAbsorption, the zero-sequence component of which is passed through a filter resistor RHEarth resistance RE2Absorption; the current of low frequency harmonic wave (harmonic wave with frequency less than working frequency) is shunted to discharge coil TV and grounding resistor RE2And a neutral grounding loop of the external power distribution grid system;in the fundamental current, the fundamental balance current is shunted to the series reactor L1And a compensation capacitor C1Forming a fundamental wave balance current loop; the fundamental wave unbalanced current, the system single-phase grounding capacitance current and the harmonic zero-sequence component current are divided by the zero-sequence channel to flow through the grounding resistor RE2Discharging; the surge current is shunted to a surge current (lightning) double discharge path formed by the auxiliary arrester F2 and the bus arrester F1.
The shunting method can greatly reduce the fundamental wave loss heating of the device and the waveform distortion caused by the current leakage of the lightning arrester.
(6) And (3) setting other parameters:
filter capacitor CHThe rated working voltage is selected according to the line voltage U of the power transmission line of the power distribution network, and the filter capacitor CHFundamental compensation current I ofCHShould not be greater than rated current I of series reactorLI.e. ICH≤IL。
At this time, each phase is resistant to
Figure BDA0002179339830000111
In the existing power distribution network, the automatic and intelligent trend of loads causes the traditional reactive power demand to be reduced, the voltage fluctuation at the tail end of a line is severe, and the harmonic spectrum injected into the power distribution network is complex and variable, and the factors easily cause the problems of equipment (such as a lightning arrester) damage, line overheating and automatic protection device misoperation in the power distribution network. Because the problems can not be solved well, a large amount of idle phenomena exist in the reactive power compensation device in the existing power distribution network. And the reactive power compensator among the arrester protection circuit of this embodiment can solve above-mentioned problem, multiple wave filter that component cooperation formed in its circuit can carry out full passband filtering harmonic elimination to the distribution network, and strong to high-frequency subharmonic absorbing capacity, can effectively avoid the harm of harmonic in the distribution network to each power equipment, realize effectively filtering harmonic and equipment cost lower, therefore the arrester protection circuit of this embodiment can satisfy the actual application's of distribution network demand, improve the current situation that reactive power compensator is idle in a large number in the current distribution network.
In addition, because the existing power distribution network is connected with a plurality of reactive power compensation devices, the mutual influence of the reactive power compensation devices can cause the problem that the reactive power compensation of the power distribution network is over compensated or the harmonic waves of the power distribution network are unreasonably amplified. A further object of this embodiment is to change the above-mentioned form of accessing multiple reactive power compensation devices to the existing power distribution network, standardize the reactive power compensation devices accessed to the power distribution network in this embodiment, and access the lightning arrester protection devices of these embodiments to each level of circuits of the power distribution network, such as power stations, transformer substations, and user terminals, respectively, in a distributed access manner, and can specifically access the lightning arrester protection devices of these embodiments to the positions of each level of circuits of the power distribution network where reactive power compensation needs to be performed, thereby ensuring that the effect of the balanced reactive power parameter provided by each reactive power compensation device accessed to the power distribution network is controllable, and realizing reasonable and targeted reactive power compensation to the power distribution network. Meanwhile, in the embodiment, the auxiliary lightning arrester group with the lightning arrester protection function and the reactive power compensation device are integrated into one lightning arrester protection device, and each standardized lightning arrester protection circuit connected to the power distribution network has the effects of lightning arrester protection, filtering harmonic elimination and reactive power compensation.
In a variant embodiment of this embodiment, the high-pass filter resistors R are arranged in the individual phase circuits of the arrester protection deviceHAnd a ground resistance RE2Are respectively provided with a voltage division tap, and a harmonic voltage signal source U with good high-frequency characteristic can be led out from a tap branchn～And V～The subsequent measuring circuit is convenient for high-precision measurement of harmonic frequency.
In another variation of this embodiment, the three-phase circuit branches of the lightning arrester protection device are respectively connected in series with the filter capacitor CHIs star-connected with the rear of the auxiliary lightning arrester F2, and is connected with a grounding resistor R at a star-connected pointE1And (4) connecting. The modification simplifies the high-pass filter resistors R in the three-phase circuit of the original lightning arrester protection device in the embodimentHAfter star connection, through a ground resistor RE2The structure of ground connection reduces the resistor quantity in order to reduce the cost of setting up the arrester protection circuit.
Example 5
The arrester protection device further comprises a harmonic loss energy recovery unit 50 on the basis of the embodiment 3-4, wherein the input end of the harmonic loss energy recovery unit 50 is respectively connected to a branch circuit through which harmonic current flows in the three-phase circuit of the reactive power compensation device.
Taking the circuit structure of the embodiment 4 as an example, referring to fig. 15, the circuit structure of the reactive power compensation device 41 adopted in the embodiment 5 is basically the same as the circuit structure of the reactive power compensation device 40 in the previous embodiment 4, except that each filter resistor R is differentHStar-type connection without any further connection to ground resistor RE2And is grounded. Three input ends of the harmonic loss energy recovery unit 50 are respectively connected to the filter capacitor C in each phase circuitHAnd the filter resistor RHBetween, receiving filter capacitor CHThe transmitted harmonic signals.
Referring to FIG. 16, the harmonic loss energy recovery unit 50 includes a rectifier U1-and a power consumption resistor Ro1Overvoltage protector F3DC voltmeter V and shunt FLVoltage regulating silicon chain GL and non-return diode DLFuse Ru1、Ru2Controller and parallel switch Ko1. The rectifier U1-three-phase input end is respectively connected in series to a filter capacitor C in each phase circuitHAnd the filter resistor RHAnd simultaneously tap with the filter capacitor R of each phase circuitHAnd (4) connecting. Fuse Ru1、Ru2Are respectively connected in series with the output ends at two sides of the rectifier U1 < - >, receive the direct current signals output by the rectifier and then the fuse Ru1The fuse R outputs the DC power supply flowing through to the negative electrode M-of the DC common busu2And outputting the direct current power supply flowing through to the positive electrode M + of the direct current common bus. The energy consumption resistor Ro1With said parallel switch Ko1Are connected in parallel with the fuse R after being connected in seriesu1、Ru2In the meantime. The fuse Ru2The shunt F is also connected in series with the anode M + of the common direct current busLVoltage regulating silicon chain GL and non-return diode DL. Wherein the rectifier is a three-phase full-wave rectifier bridge, and can be selected from high-voltage silicon stackThe bridge is formed. The rectifier is not easy to interfere with the harmonic absorption capacity of the system and has high reliability. The non-return diode D prevents reverse power supply from other dc sources and is used to ensure isolation and non-return for the case where the plurality of harmonic loss energy recovery units 50 operate in parallel.
The controllers are respectively connected with a switch Ko1Flow divider FLConnected with a voltage-regulating silicon chain GL for receiving the shunt FLThe output detection signal controls the length of a silicon chain access circuit in the voltage-regulating silicon chain GL and the parallel switch Ko1The voltage of the direct current power supply is adjusted, and the voltage of the direct current power supply is ensured not to exceed a threshold value. Common PLC controllers in the power system can be used as controllers in the embodiment to realize the functions, preferably, the controllers can be selected to be controllers with serial port, network port or optical port communication, so that external control signals can be conveniently received, and integrated control can be realized after the power distribution network is accessed.
DC voltmeter V and overvoltage protector F3Are respectively connected in parallel with the fuse Ru1、Ru2And the overvoltage protector can limit and protect the harmonic loss energy recovery unit when the voltage of the direct current power supply exceeds a limit peak value.
When in work, harmonic current flowing through the three-phase circuit of the lightning arrester protection device is respectively transmitted from each filter capacitor CHFlows into the rectifier U1-Rectified and converted into a direct current power supply. The negative pole of the DC power supply outputs a signal to the fuse Ru1Then inputting the signal into the negative pole of the common DC bus, and the electrical signals output by the positive pole of the DC power supply sequentially flow through the fuse Ru2Flow divider FLVoltage regulating silicon chain GL and non-return diode DLAnd then input into the anode of the common direct current bus. At the same time, the flow divider FLDetecting the current flowing through the current divider, and outputting a detection signal to the controller according to the current divider FLInput signal adjusts the length of the silicon chain access circuit in the voltage-regulating silicon chain GL and the parallel switch Ko1The voltage of the direct current power supply is adjusted,and ensuring that the voltage of the direct-current power supply does not exceed a threshold value.
Wherein, assuming that the high-frequency characteristics of the rectifier silicon stack meet all the requirements of harmonic rectification output, then:
outputting direct current voltage U after n-th harmonic rectificationdn＝1.35Un～Wherein, Un～For filtering capacitors R on the circuits of the respective phasesHAt harmonic voltage, n is the harmonic order.
All harmonic rectified DC voltage
Figure BDA0002179339830000141
Output direct current
Figure BDA0002179339830000142
Wherein IRHnTo flow through the filter capacitor RHThe nth harmonic current of (a).
According to different output voltage values obtained after the adjustment of the control unit, the direct current power supply output by the harmonic loss energy recovery unit can be supplied to different electric power equipment. When the output voltage value is lower, the direct current power supply can be supplied to a low-voltage lighting circuit; when the output voltage is 220V of national standard DC supply voltage, the output voltage can be used as a general DC power supply to corresponding general electric equipment or used as an emergency power supply UPS. In addition, the existing inversion technology can be adopted to convert the direct current power supply into 380V standard alternating current, and the alternating current is input into the power distribution network again, so that harmonic loss energy can be fed back to the power grid.
Similarly, when the harmonic loss energy recovery unit 50 is connected to the lightning arrester protection device in embodiment 3, three input ends of the rectifier are respectively connected to the ends of the capacitor C of the three-phase circuit of the reactive power compensation device 30, so as to transfer and recover the harmonic loss energy of the distribution network.
Compared with the existing reactive power compensation device, the lightning arrester protection device is smaller than the bus lightning arrester by setting the rated voltage value, so that the auxiliary lightning arrester can be conducted and discharge overvoltage prior to the bus lightning arrester, and the protection of all homologous equipotential bus lightning arresters on the power distribution network bus is realized. All in oneWhen the power distribution network is used, the current limiting is realized through the filter capacitor, the fault auxiliary lightning arrester is isolated, the auxiliary lightning arrester is protected and is convenient to replace, further, the bus lightning arrester is matched with the auxiliary lightning arrester, the lightning stroke resistance of the power distribution network is enhanced, and the insulating property of the power distribution network is improved. Further, a filter capacitor CHFilter resistor RHEarth resistance RE2And the neutral point grounding device is combined to filter harmonic waves of a three-phase circuit harmonic wave full pass band and eliminate resonance, so that the influence of harmonic waves and severe fluctuating voltage in the power distribution network can be reduced, and further, the condition that the lightning arrester and the auxiliary lightning arrester are in misoperation conduction, single long-time conduction or multiple conduction in a short time is avoided by each bus, and further, the condition that the lightning arrester absorbs too high heat or explodes is avoided. Further, the harmonic loss energy recovery unit realizes the transfer recovery of the harmonic loss energy in the power distribution network. Further, a ground resistance RE2The resonance suppression of the grounding loop is realized, when the arc suppression coil is out of control, the inductance of the damping arc suppression coil and the capacitance of the circuit to the ground resonate, and the harmonic overvoltage amplitude is limited, so that the stability of the power distribution network is facilitated. Further, the lightning arrester protection device relieves the heating phenomenon of the existing reactive power compensation device by reducing the fundamental wave loss of the filter resistor.
The above-mentioned embodiments only express one embodiment of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention.

Claims (10)

1. A lightning arrester protection device, characterized in that: the lightning arrester comprises an auxiliary lightning arrester group, wherein the auxiliary lightning arrester group is a three-phase circuit, each phase of circuit comprises a filter capacitor and an auxiliary lightning arrester which are connected in series, and the filter capacitor of each phase of circuit is respectively connected with a corresponding phase of circuit in a three-phase power distribution network bus; the auxiliary lightning arrester of each phase circuit is grounded after the tail ends of the phase branches are connected in a star shape together; the rated voltage values of the auxiliary arresters are the same and are lower than the conduction voltage of the bus arrester connected in series to the power distribution network bus.
2. A surge arrester protection device according to claim 1, characterized in that: and the conduction voltage value of the auxiliary lightning arrester is between the rated line voltage of each phase of power transmission line of the power distribution network and the rated phase voltage of each phase of power transmission line of the power distribution network.
3. A surge arrester protection device according to claim 2, characterized in that: the auxiliary lightning arrester group comprises 4 auxiliary lightning arresters, and each auxiliary lightning arrester in the three-phase circuit of the auxiliary lightning arrester group is grounded through one auxiliary lightning arrester after the tail ends of the branch circuits of each phase are connected in a star shape together.
4. A surge arrester protection device according to claim 1, characterized in that: the lightning arrester protection device also comprises a reactive compensation device, wherein the reactive compensation device is a three-phase circuit and is respectively connected with a three-phase bus of the power distribution network; and each filter capacitor of the auxiliary lightning arrester group is respectively connected with the three-phase circuit of the reactive power compensation device.
5. An arrester protection device according to claim 4, characterized in that: each phase circuit of the reactive power compensation device comprises a series reactor, a fuse and a capacitor which are sequentially connected in series, and a discharge coil which is connected with the fuse and the capacitor in parallel; and a filter capacitor on each phase circuit of the auxiliary lightning arrester group is respectively connected between a current transformer and a series reactor in one phase circuit of the reactive power compensation device.
6. An arrester protection device according to claim 4, characterized in that: the reactive power compensation device comprises a zero sequence current transformer, and each phase circuit of the reactive power compensation device comprises a high-pass filter resistor, a series reactor and a compensation capacitor which are connected in series; the series reactor of each phase circuit of the reactive power compensation device is respectively connected in series between the filter capacitor and the auxiliary lightning arrester in the three-phase circuit of the auxiliary lightning arrester group, and the compensation capacitors of the reactive power compensation device are connected in a star shape together at the tail ends of the branch circuits where the compensation capacitors are located; the zero sequence current transformer is connected in series between a filter capacitor and a series reactor on a three-phase circuit of the reactive power compensation device; one end of a high-pass filter resistor of each phase circuit of the reactive power compensation device is respectively connected in series between a zero sequence current transformer and a filter capacitor on the phase circuit, and the other end of the high-pass filter resistor is connected with the tail end of the branch circuit in a common star shape.
7. An arrester protection device according to claim 4, characterized in that: the reactive power compensation device comprises a zero sequence current transformer, and each phase circuit of the reactive power compensation device comprises a high-pass filter resistor, a series reactor and a compensation capacitor which are connected in series; the series reactor of each phase circuit of the reactive power compensation device is respectively connected in series between the filter capacitor and the auxiliary lightning arrester in the three-phase circuit of the auxiliary lightning arrester group, and the compensation capacitors of the reactive power compensation device are connected in a star shape together at the tail ends of the branch circuits where the compensation capacitors are located; the zero sequence current transformer is connected in series between a filter capacitor and a series reactor on a three-phase circuit of the reactive power compensation device; one end of a high-pass filter resistor of each phase circuit of the reactive power compensation device is respectively connected between a zero sequence current transformer and a filter capacitor on the phase circuit in series, and the other end of the high-pass filter resistor is connected with the tail end of the branch circuit in a common star shape and then grounded through a grounding resistor.
8. An arrester protection device according to claims 5-7, characterized in that: the lightning arrester protection device also comprises a harmonic loss energy recovery unit, wherein the harmonic loss energy recovery unit comprises a rectifier, a controller, a current divider, a voltage regulating silicon chain and a non-return diode, wherein the current divider, the voltage regulating silicon chain and the non-return diode are sequentially connected to the anode output end of the rectifier in series; the controller is respectively connected with the shunt and the voltage regulating silicon chain, receives an input signal of the shunt and outputs an electric signal to the voltage regulating silicon chain; and three input ends of the rectifier are respectively connected in series with a branch circuit through which harmonic current flows in the three-phase circuit of the reactive power compensation device.
9. A method of protecting an arrester of a power distribution network, characterized by: and arranging an auxiliary lightning arrester group on the power distribution network bus, wherein the rated voltage value of each auxiliary lightning arrester in the auxiliary lightning arrester group is lower than the breakover voltage of the bus lightning arrester.
10. A method of protecting an arrester for a power distribution network as claimed in claim 9, characterized in that: the auxiliary lightning arrester group is a three-phase circuit, and each phase of circuit comprises a filter capacitor and an auxiliary lightning arrester which are connected in series; the method comprises the following steps that a reactive power compensation device is arranged on a power distribution network bus, the reactive power compensation device is a three-phase circuit which is respectively connected with the three-phase bus of the power distribution network, the reactive power compensation device comprises a zero sequence current transformer, and each phase circuit of the reactive power compensation device comprises a high-pass filter resistor, a series reactor and a compensation capacitor which are connected in series; the series reactor of each phase circuit of the reactive power compensation device is respectively connected in series between the filter capacitor and the auxiliary lightning arrester in the three-phase circuit of the auxiliary lightning arrester group, and the compensation capacitors of the reactive power compensation device are connected in a star shape together at the tail ends of the branch circuits where the compensation capacitors are located; the zero sequence current transformer is connected in series between a filter capacitor and a series reactor on a three-phase circuit of the reactive power compensation device; one end of a high-pass filter resistor of each phase circuit of the reactive power compensation device is respectively connected between a zero sequence current transformer and a filter capacitor on the phase circuit in series, and the other end of the high-pass filter resistor is connected with the tail end of the branch circuit in a common star shape and then grounded through a grounding resistor; setting the rated voltage value of the auxiliary lightning arrester to be between the line voltage of each phase of power transmission line of the power distribution network and the phase voltage of each phase of power transmission line of the power distribution network; setting the reactance value of the compensation capacitor to be equal to the reactance value of the series reactor; setting reactance of the filter capacitor
Figure FDA0002179339820000021
Wherein U is said power line voltage, ILRated current of the series reactor; setting the resistance R of the filter resistorHAnd resistance value R of ground resistorE2Satisfies 0.35Ie×(RH+3RE2)≤UrWherein U isrIs the rated voltage of the lightning arrester,Ieis the rated current of the filter capacitor.
CN201910790254.0A 2019-08-26 2019-08-26 Lightning arrester protection device and lightning arrester protection method Pending CN110690688A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111431158A (en) * 2020-04-23 2020-07-17 佛山科学技术学院 Overvoltage combined suppression system and device of vacuum circuit breaker

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111431158A (en) * 2020-04-23 2020-07-17 佛山科学技术学院 Overvoltage combined suppression system and device of vacuum circuit breaker
CN111431158B (en) * 2020-04-23 2021-11-05 佛山科学技术学院 Overvoltage combined suppression system and device of vacuum circuit breaker

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