CN114069585A - Flexible fusion arc extinction method for single-phase earth fault of power distribution network - Google Patents

Flexible fusion arc extinction method for single-phase earth fault of power distribution network Download PDF

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CN114069585A
CN114069585A CN202111344747.5A CN202111344747A CN114069585A CN 114069585 A CN114069585 A CN 114069585A CN 202111344747 A CN202111344747 A CN 202111344747A CN 114069585 A CN114069585 A CN 114069585A
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郭谋发
游建章
高伟
洪翠
杨耿杰
郑泽胤
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Fuzhou University
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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
    • H02H9/08—Limitation or suppression of earth fault currents, e.g. Petersen coil
    • 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
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    • Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
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Abstract

The invention provides a flexible fusion arc extinction method for a single-phase earth fault of a power distribution network, which adopts a cascade H-bridge converter as a flexible fusion arc extinction device, is based on a current-voltage double closed-loop controller and simultaneously takes fault point current and fault point voltage as control targets. The provided fusion arc extinction method does not need complex switching conditions, the two arc extinction methods are simultaneously realized on a set of flexible arc extinction device, and compared with an arc extinction method in which an arc extinction coil and an arc extinction cabinet are used in a matched mode, the input of equipment and the cooperation among different devices are saved. The flexible arc suppression device is not only suitable for a neutral point ungrounded system, but also suitable for a neutral point arc suppression coil grounded system, is slightly influenced by transient current of an arc suppression coil and line impedance voltage drop, and has the advantages of a flexible current arc suppression method and a flexible voltage arc suppression method. And a powerful technical guarantee is provided for popularization and application of the flexible arc extinction technology in different power distribution systems.

Description

Flexible fusion arc extinction method for single-phase earth fault of power distribution network
Technical Field
The invention belongs to the technical field of operation maintenance and fault treatment of a power system and arc extinction of single-phase earth faults of a power grid, and particularly relates to a flexible fusion arc extinction method for single-phase earth faults of a power distribution network.
Background
Forest fire, equipment burning, personal electric shock and other accidents caused by single-phase earth faults of the power distribution network occur, and particularly, ferromagnetic resonance, interphase short circuit and other secondary accidents are easily caused by arc earth faults. Therefore, the suppression of the single-phase earth fault arc of the power distribution network has important significance. The most of the arc extinguishing devices widely used at present are passive arc extinguishing devices, and mainly comprise two types: arc suppression coil and arc suppression cabinet. The working principle of the arc suppression coil can be returned to a passive current arc suppression method, the arc suppression coil is connected to a neutral point, the neutral point voltage after the ground fault generates inductive current on the arc suppression coil, and capacitive current generated by the ground fault is compensated, so that the fault point electric arc is easily extinguished. And the arc suppression cabinet transfers the fault point current at the unknown position to the metallic grounding at the bus in a fault transfer mode. The method can suppress the fault phase voltage at the bus to be close to zero, suppress the recovery voltage of the fault point, make the electric arc difficult to reignite, and can be classified as a voltage arc extinction method.
The main problems of the arc suppression coil are as follows: only the reactive component in the earth fault current can be compensated, the harmonic component and the active component cannot be compensated, and the intermittent arc earth fault cannot be restrained. The main problems of the arc extinguishing cabinet are as follows: the impact on the system is large when the device is put into and taken out of the device, and ferromagnetic resonance is easily caused when the device is particularly taken out of the device, so that the device is generally used together with a resonance elimination device. In addition, when a metallic ground fault occurs, the effect of compensating for the current at the fault point is not good. In addition, it cannot be applied to a low-resistance ground fault occurring at the end of a heavy-duty line, and may even increase the fault point current.
Aiming at the problem of the arc suppression coil, scholars at home and abroad propose an active (flexible) arc suppression technology based on a power electronic converter, the power electronic converter is used as an arc suppression device or as the supplement of the arc suppression coil, active and harmonic components and transient components which cannot be compensated by the arc suppression coil are compensated, and theoretically, the full compensation of earth fault current and the suppression of intermittent arc overvoltage can be realized. However, the flexible arc suppression device based on the current arc suppression principle (the current at the fault point is used as the control object) has the following problems: one is the need to measure ground parameters, including capacitance to ground and leakage resistance to ground, which requires high accuracy for ground parameter measurement techniques. Secondly, the harmonic and transient components of the ground fault are difficult to extract or calculate, so that the compensation implementation difficulty of the harmonic and transient components is high, and the research and report on the contents are relatively rare. And thirdly, for a resonant grounding system, the compensation effect of the method under the condition of high-resistance grounding fault is very small. The flexible arc extinction device based on the voltage extinction principle (taking the fault phase voltage as the control object) has the following problems: firstly, the risk of increasing fault point current exists when a low-resistance earth fault occurs at the tail end of a heavy-load circuit. And secondly, for a resonant grounding system, the device has larger direct current quantity of injected current. Thirdly, the compensation effect of the metallic grounding fault on the fault current is small, the fault current is still large, and the risk of personal electric shock exists.
The existing flexible self-adaptive arc extinction method mainly solves the problems of the current arc extinction method and the voltage arc extinction method by switching the current arc extinction method and the voltage arc extinction method. If the current arc extinction method is used during low-resistance earth faults, and the voltage arc extinction method is used during high-resistance earth faults, on one hand, the switching condition calculation is complex, and the realization is difficult; on the other hand, the low-resistance earth fault still has the problems that the current method is inherently influenced by the measurement precision of the ground parameters by using the current arc extinction method alone, and the like, and similarly, the high-resistance fault still has the problem that the direct-current quantity of the device injection current in the resonance earth system is large by using the voltage arc extinction method alone.
Disclosure of Invention
In order to make up for the blank and the deficiency of the prior art, the invention provides a flexible fusion arc extinction method for a single-phase earth fault of a power distribution network, which adopts a cascade H-bridge converter as a flexible fusion arc extinction device, designs a current-voltage double closed-loop controller, simultaneously adopts the current and the voltage of a fault point as control targets, respectively designs a flexible fusion arc extinction device injection current controller and a system zero sequence voltage controller, superposes the output of the current and voltage controllers and the voltage of a grid-connected point as a final control target of the flexible fusion arc extinction device, obtains a driving signal of a power electronic element after modulation algorithm modulation, suppresses the voltage of the fault point and simultaneously compensates the current of the fault point, and realizes the fusion of the current arc extinction method and the voltage arc extinction method. The provided fusion arc extinction method does not need complex switching conditions, the two arc extinction methods are simultaneously realized on a set of flexible arc extinction device, and compared with an arc extinction method in which an arc extinction coil and an arc extinction cabinet are matched, the input of equipment and the cooperation among different devices are saved; the flexible arc suppression device is not only suitable for a neutral point ungrounded system, but also suitable for a neutral point arc suppression coil grounded system, is slightly influenced by transient current of an arc suppression coil and line impedance voltage drop, and has the advantages of a flexible current arc suppression method and a flexible voltage arc suppression method. And a powerful technical guarantee is provided for popularization and application of the flexible arc extinction technology in different power distribution systems.
The invention specifically adopts the following technical scheme:
a flexible fusion arc extinction method for single-phase earth faults of a power distribution network is characterized by comprising the following steps: a cascaded H-bridge converter is adopted as a flexible fusion arc suppression device, a current-voltage double closed-loop controller is based on, and meanwhile, fault point current and fault point voltage are used as control targets. Therefore, the fusion of a current arc extinction method and a voltage arc extinction method is realized, and the two arc extinction methods simultaneously play a role in a set of flexible fusion arc extinction device.
Furthermore, the cascaded H-bridge type converter adopts a single-phase cascaded H-bridge converter and is directly connected with a neutral point or a certain phase line of a distribution line in a hanging mode, or adopts a two-phase cascaded H-bridge converter which is directly connected with two phases of the distribution line in a hanging mode, or adopts a three-phase cascaded H-bridge converter which is connected in a star mode, a common point is connected with the ground through a switch or directly connected with the ground or connected with the ground through the single-phase cascaded H-bridge converter, and the three-phase cascaded H-bridge converter is directly connected with a three-phase line of the distribution line in a hanging mode.
Further, the fault point current is taken as a control target, and the target given quantity of the fault point current is obtained by multiplying the ground parameter by the negative value of the fault phase power supply voltage; the feedback quantity is an actual measurement value of the current injected by the flexible fusion arc suppression device; the closed-loop controller adopts one of PID control, PR control, inversion control, sliding mode control and model prediction control.
Further, the voltage of a fault point is taken as a control target, the target given quantity of the voltage is a negative value of the power supply voltage of the fault phase, and the feedback quantity is the zero sequence voltage of the system or the neutral point voltage of the system; the closed-loop controller adopts one of PID control, PR control, inversion control, sliding mode control and model prediction control.
Further, the output of the flexible current closed-loop controller and the flexible voltage closed-loop controller and the voltage of the grid-connected point are superposed to be used as a final control target of the flexible arc-extinguishing fusion arc-extinguishing device, and the injected current and the system zero sequence voltage of the flexible arc-extinguishing fusion arc-extinguishing device are regulated and controlled at the same time.
Further, the injection current of the flexible fusion arc suppression device is as follows:
Figure BDA0003352235960000031
if the output voltage of the flexible arc suppression device is controlled to be a voltage negative value before the fault point fault, namely:
UZ＝-U′f
the voltage at the fault point is Uf＝UZ+U'fZero, and the neutral point voltage is taken as a control target;
wherein zero sequence voltage U is set for zero fault point current0Must be negative in the fault phase supply voltage, i.e. U0＝-Ef(ii) a The leakage resistance to ground and the capacitance to ground of the system are three-phase symmetrical and are r0And C0(ii) a L is the equivalent inductance of the arc suppression coil, j represents a complex number, and omega represents the angular frequency.
Compared with the prior art, the invention and the optimized scheme thereof have the following beneficial effects:
1. compared with an independent current arc extinction method, the flexible fusion arc extinction method provided by the invention is less influenced by the ground parameter measurement precision, less influenced by the line impedance voltage drop and better in compensation effect during the metallic grounding fault in a neutral point ungrounded system.
2. Compared with an independent current arc suppression method, the flexible fusion arc suppression method provided by the invention has small influence on the ground parameter measurement precision in a system with a neutral point grounded through an arc suppression coil, and has a better suppression effect on fault phase voltage during medium-high resistance ground fault; compared with a single voltage arc extinction method, the device is less influenced by line impedance voltage drop, has better compensation effect in the case of metal grounding fault, and has no larger and slowly-attenuated direct current quantity of the injected current.
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The invention is described in further detail below with reference to the following figures and detailed description:
FIG. 1 is a schematic diagram of a circuit principle of a flexible fusion arc suppression device using a cascaded H-bridge converter according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of an equivalent circuit principle of a fusion arc suppression method according to an embodiment of the invention;
FIG. 3 is a schematic diagram of a control strategy of a fusion arc suppression method according to an embodiment of the invention;
FIG. 4 is a graph comparing the effects of the fusion arc suppression method with the current arc suppression method and the voltage arc suppression method according to the embodiment of the present invention;
fig. 5 is a comparison graph of arc extinction effects of the fusion arc extinction method and the voltage arc extinction method in the low-resistance ground fault according to the embodiment of the invention.
Detailed Description
In order to make the features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail as follows:
the embodiment shown in fig. 1 provides a design of a flexible fusion arc extinction method for a single-phase earth fault of a power distribution network, the equivalent circuit is shown in figure 2, a cascade H-bridge converter is taken as a flexible fusion arc suppression device, a controller consists of a current-voltage double closed-loop controller, simultaneously, the current and the voltage of a fault point are taken as control targets, a flexible fusion arc suppression device injection current controller and a system zero sequence voltage controller are respectively designed, the output of the current and voltage controller, the grid-connected point voltage and the grid-connected point voltage are superposed to be used as a final control target of the flexible fusion arc suppression device, a driving signal of a power electronic element is obtained after modulation of a modulation algorithm, the fault point voltage is suppressed, and the fault point current is compensated at the same time, so that fusion of a current arc suppression method and a voltage arc suppression method is realized, and the two arc suppression methods simultaneously play a role in a set of flexible fusion arc suppression device.
Specifically, in the flexible fusion arc suppression device, a topological structure adopts a cascaded H-bridge converter, which can be a single-phase cascaded H-bridge converter and is directly connected to a neutral point or a phase line of a distribution line in a hanging manner; or the two-phase cascade H-bridge converter is directly connected with two phases of the distribution line in a hanging manner; or the three-phase cascade H-bridge converter is connected in a star manner, the common point is grounded through a switch or directly or through a single-phase cascade H-bridge converter, and the three-phase cascade H-bridge converter is directly connected to the three-phase line of the distribution line in a hanging manner.
When the flexible current closed-loop controller is used as a flexible current closed-loop controller, the fault point current is used as a control target, and the target given quantity is obtained by multiplying the ground parameter and the negative value of the fault phase power supply voltage. The feedback quantity is an actual measurement value of the injection current of the flexible fusion arc suppression device. The closed-loop controller adopts PID control.
When the flexible voltage closed-loop controller is used as a flexible voltage closed-loop controller, the voltage of a fault point is taken as a control target, the target given quantity is a negative value of the voltage of a fault phase power supply, and the feedback quantity is the zero sequence voltage of a system or the neutral point voltage of the system. The closed-loop controller adopts PID control.
The adopted flexible fusion arc extinction method is characterized in that the output of the flexible current closed-loop controller and the flexible voltage closed-loop controller and the voltage of a grid-connected point are superposed to be used as a final control target of the flexible fusion arc extinction device, and the injection current and the system zero sequence voltage of the flexible arc extinction fusion arc extinction device are regulated and controlled. The control block diagram is shown in fig. 3.
The technical solution of the present embodiment is explained in detail from the principle perspective as follows:
1. principle of flexible arc extinction
According to ohm's law, the voltage and current relationship at the fault point is
Figure BDA0003352235960000051
Thus, the fault point voltage is zero when the fault point current is zero. However, in the case of a metallic ground fault, the fault point voltage is zero and the fault point current is not zero. The ideal arc suppression result is that the fault point voltage and fault point current are zero at the same time.
From fig. 2, it can be derived from Kirchhoff's Voltage Law (KVL):
U0+U′f-Uf＝0 (2)
assuming that the ground fault occurs at the phase A of the bus, the three phases of the system before the ground fault are symmetrical to the ground parameter, namely the zero sequence voltage U 'of the system before the fault'0Is zero, the voltage of the fault point before the fault is U'f＝EA+U'0＝EATo make the fault point voltage UfAs shown in equation (2), the zero-sequence voltage must be zero:
U0＝-U′f＝-EA (3)
the fault point current at this time is:
Figure BDA0003352235960000052
as can be seen from the equations (3) and (4), the fault point current is zero and has a transition resistance R with the ground faultfIs irrelevant.
From fig. 2, it can be derived from Kirchhoff's Current Law (KCL):
IZ+IL-IR-IC-If＝0 (5)
let the fault point current be zero, then the injected current is:
IZ＝IR+IC-IL (6)
then fault point current IfIs suppressed to zero. Leakage resistance to ground current I of faulty feederRiCapacitive current to ground ICiAnd earth fault current IfMixingTogether, the flexible arc-extinguishing device therefore compensates the current IZCannot be obtained by real-time detection and extraction. But can be calculated by the voltage to ground and the parameter to ground, and the calculation method is as follows:
Figure BDA0003352235960000061
in the formula, ri(i ═ A, B, C) and Ci(i ═ A, B, C) are leakage resistance to earth and capacitance to earth, and assuming three-phase symmetry of leakage resistance to earth and capacitance to earth, r is the same0And C0. The relation between each phase voltage and each phase power supply voltage is substituted into formula (7) and the relation is arranged to obtain
Figure BDA0003352235960000062
From equation (4), to make the fault point current zero, the zero sequence voltage must be the negative value of the fault phase power supply voltage, i.e., U0＝-EA. The injection current of the flexible arc suppression device is as follows:
Figure BDA0003352235960000063
in this case, the injection current is used as a control target, and may be referred to as a current extinction method.
If the output voltage of the flexible arc suppression device is controlled to be a positive value of the pre-fault voltage of the fault point, namely
UZ＝-U′f (10)
The voltage at the fault point is Uf＝UZ+U'fAnd is zero, and the neutral point voltage is taken as a control target at the moment, so that the method can be called a voltage arc extinction method.
2. Flexible fusion arc extinguishing principle
As can be seen from the formulas (8) and (9), when the current arc extinction method is adopted alone, the injected current of the flexible arc extinction device is controlled to be the reference current value shown in the formula (9), and the zero sequence voltage is regulated and controlled to be U at the moment0＝-EA(ii) a While independently adopting electricityAnd when the arc extinction method is carried out, namely the zero-sequence voltage is controlled to be a negative value of the fault phase power supply voltage, and the current injected by the flexible arc extinction device is regulated and controlled to be the current shown in the formula (9). Therefore, no matter a current arc extinction method or a voltage arc extinction method is adopted, the ideal regulation result is that the fault point current and the fault point voltage are zero, the regulation targets of the fault point current and the fault point voltage are consistent, and no conflict exists. Based on the principle, the flexible fusion arc extinction method simultaneously regulates and controls the injection current of the flexible arc extinction device and the zero sequence voltage of the system, the injection current of the flexible arc extinction device is controlled to be the reference current shown in the formula (9) by a current controller, and the zero sequence voltage of the system is controlled to be a negative value of the power supply voltage of the fault phase by a voltage controller. The current and voltage are regulated and controlled simultaneously by the double controllers, so that the current and the voltage of a fault point are regulated and controlled to be zero more quickly and accurately, and an equivalent circuit diagram of the working principle of the double controllers is shown in fig. 2.
In a resonance grounding system, the influence of transient current of an arc suppression coil is utilized, a single current arc suppression method has poor suppression effect on fault phase voltage under the condition of high-resistance grounding fault, and the device of the single voltage arc suppression method injects current with larger direct current quantity. The flexible fusion arc extinction method controls the zero sequence voltage of the system, and the zero sequence voltage clamped by the voltage controller is a fault phase power supply voltage negative value, so that the fault phase voltage can still be suppressed to a lower value under the condition of high-resistance ground fault; and simultaneously, the current controller regulates and controls the current injected by the device to be a full compensation current value, so that the direct current quantity of the device is quickly attenuated.
In order to make the technical solution of the present invention better understood by those of ordinary skill, the following further describes the solution of the present embodiment with reference to a simulation example.
And (4) constructing a power distribution network simulation model containing 4 feeders by using PSCAD/EMTDC software. The distribution line adopts a Bergeron model. The compensation effects of setting the phase a ground fault at 0.2s, putting a flexible arc extinction device at 0.3s, setting the ground transition resistance to 3000 Ω, and using the flexible current arc extinction method alone, the voltage arc extinction method alone, and the fusion arc extinction method in the resonant grounding system are shown in fig. 4. As can be seen from fig. 4, when the flexible current arc extinction method is adopted alone, the suppression effect of the fault phase voltage is very small, and the residual voltage is still very large; when a voltage arc extinction method is singly adopted, the voltage of a fault phase is suppressed to a lower value, but the device injects current with larger direct current quantity; the fusion arc extinction method can effectively suppress the fault phase voltage, and the device has small injected current direct current quantity and is quickly attenuated to be close to zero.
In the neutral point ungrounded system, a metallic earth fault and a low-impedance earth fault at the end of a heavy-load line are respectively arranged at a bus, namely, a 5-ohm earth fault occurs at the end of a 10km cable line with the load current of 280A, and the compensation effects of adopting a flexible current arc extinction method alone, a voltage arc extinction method alone and a fusion arc extinction method are shown in fig. 5. As can be seen from fig. 5, the voltage arc suppression method has a poor arc suppression effect in the case of a metallic ground fault and a low-resistance ground fault at the end of a heavy-duty line. And the arc extinction effects of the fusion arc extinction method and the current arc extinction method are close, and the voltage of a fault point can be effectively inhibited and the current of the fault point can be compensated.
The embodiment provides a fusion arc extinction method which simultaneously applies a current arc extinction principle and a voltage arc extinction principle on a set of flexible arc extinction device. The method is characterized in that a cascade H-bridge converter is used as a flexible fusion arc suppression device, a current-voltage double closed-loop controller is designed, fault point current and fault point voltage are used as control targets, a flexible fusion arc suppression device injection current controller and a system zero sequence voltage controller are respectively designed, the output of the current and voltage controllers and grid-connected point voltage are superposed to be used as a final control target of the flexible fusion arc suppression device, a driving signal of a power electronic element is obtained after modulation algorithm modulation, the fault point voltage is suppressed, the fault point current is compensated, and fusion of a current arc suppression method and a voltage arc suppression method is achieved. The provided fusion arc extinction method does not need complex switching conditions, the two arc extinction methods are simultaneously realized on a set of flexible arc extinction device, and compared with an arc extinction method in which an arc extinction coil and an arc extinction cabinet are matched, the input of equipment and the cooperation among different devices are saved; the flexible arc suppression device is not only suitable for a neutral point ungrounded system, but also suitable for a neutral point arc suppression coil grounded system, is slightly influenced by transient current of an arc suppression coil and line impedance voltage drop, and has the advantages of a flexible current arc suppression method and a flexible voltage arc suppression method. And a powerful technical guarantee is provided for popularization and application of the flexible arc extinction technology in different power distribution systems.
The present invention is not limited to the above-mentioned preferred embodiments, and any person can derive other various forms of flexible fusion arc-extinguishing method for single-phase earth fault of power distribution network according to the teaching of the present invention.

Claims (6)

1. A flexible fusion arc extinction method for single-phase earth faults of a power distribution network is characterized by comprising the following steps: a cascaded H-bridge converter is adopted as a flexible fusion arc suppression device, and based on a current-voltage double closed-loop controller, fault point current and fault point voltage are taken as control targets.
2. The power distribution network single-phase earth fault flexible fusion arc extinction method according to claim 1, characterized in that: the cascaded H-bridge type converter adopts a single-phase cascaded H-bridge converter and is directly connected with a neutral point or a certain phase line of a distribution line in a hanging mode, or adopts a two-phase cascaded H-bridge converter which is directly connected with two phases of the distribution line in a hanging mode, or adopts a three-phase cascaded H-bridge converter which is connected with the three-phase cascaded H-bridge converter in a star mode, a common point is connected with the ground through a switch or directly or through the single-phase cascaded H-bridge converter, and the three-phase cascaded H-bridge converter is directly connected with three phase lines of the distribution line in a hanging mode.
3. The power distribution network single-phase earth fault flexible fusion arc extinction method according to claim 1, characterized in that: the current of the fault point is taken as a control target, and the target given quantity is obtained by the product of the ground parameter and the negative value of the voltage of the fault phase power supply; the feedback quantity is an actual measurement value of the current injected by the flexible fusion arc suppression device; the closed-loop controller adopts one of PID control, PR control, inversion control, sliding mode control and model prediction control.
4. The power distribution network single-phase earth fault flexible fusion arc extinction method according to claim 1, characterized in that: taking the voltage of a fault point as a control target, wherein the target given quantity is a negative value of the power voltage of the fault phase, and the feedback quantity is the zero sequence voltage of the system or the neutral point voltage of the system; the closed-loop controller adopts one of PID control, PR control, inversion control, sliding mode control and model prediction control.
5. The power distribution network single-phase earth fault flexible fusion arc extinction method according to claim 1, characterized in that: and the output of the flexible current closed-loop controller and the flexible voltage closed-loop controller and the voltage of the grid-connected point are superposed to be used as a final control target of the flexible arc-extinguishing fusion arc-extinguishing device, and the injected current and the system zero-sequence voltage of the flexible arc-extinguishing fusion arc-extinguishing device are regulated and controlled.
6. The power distribution network single-phase ground fault flexible fusion arc extinction method according to claim 5, characterized in that:
the injection current of the flexible fusion arc suppression device is as follows:
Figure FDA0003352235950000011
if the output voltage of the flexible arc suppression device is controlled to be a voltage negative value before the fault point fault, namely:
UZ＝-U′f
the voltage at the fault point is Uf＝UZ+U′fZero, and the neutral point voltage is taken as a control target;
wherein zero sequence voltage U is set for zero fault point current0Must be negative in the fault phase supply voltage, i.e. U0＝-Ef(ii) a The leakage resistance to ground and the capacitance to ground of the system are three-phase symmetrical and are r0And C0(ii) a L is the equivalent inductance of the arc suppression coil, j represents a complex number, and omega represents the angular frequency.
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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105610147A (en) * 2016-03-24 2016-05-25 福州大学 Distribution network ground fault arc suppression method based on three-phase cascade H bridge converters
EP3506445A1 (en) * 2017-12-27 2019-07-03 ABB Schweiz AG System for identification of a feeder with high-ohmic earth fault in a distribution network
CN112234596A (en) * 2020-10-15 2021-01-15 福州大学 Flexible self-adaptive arc extinction method for single-phase earth fault of power distribution network
CN113036730A (en) * 2021-04-19 2021-06-25 福州大学 Control method of power distribution network single-phase earth fault flexible arc extinction device
CN113097989A (en) * 2021-04-16 2021-07-09 长沙理工大学 Fault composite arc extinction method for flexible grounding power distribution network

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105610147A (en) * 2016-03-24 2016-05-25 福州大学 Distribution network ground fault arc suppression method based on three-phase cascade H bridge converters
EP3506445A1 (en) * 2017-12-27 2019-07-03 ABB Schweiz AG System for identification of a feeder with high-ohmic earth fault in a distribution network
CN112234596A (en) * 2020-10-15 2021-01-15 福州大学 Flexible self-adaptive arc extinction method for single-phase earth fault of power distribution network
CN113097989A (en) * 2021-04-16 2021-07-09 长沙理工大学 Fault composite arc extinction method for flexible grounding power distribution network
CN113036730A (en) * 2021-04-19 2021-06-25 福州大学 Control method of power distribution network single-phase earth fault flexible arc extinction device

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
郑泽胤等: "配电网三相直挂式柔性消弧方法与样机实验研究", 电力系统及其自动化学报, vol. 32, no. 5, pages 1 - 8 *

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