WO2021073323A1

WO2021073323A1 - Ground fault current compensation system, method and apparatus for self-produced phase power supply

Info

Publication number: WO2021073323A1
Application number: PCT/CN2020/114341
Authority: WO
Inventors: 刘红文; 王科; 赵现平; 姜虹云; 沈龙; 张恭源
Original assignee: 云南电网有限责任公司电力科学研究院
Priority date: 2019-10-18
Filing date: 2020-09-10
Publication date: 2021-04-22
Also published as: CN110611317A

Abstract

A ground fault current compensation system, method and apparatus for a self-produced power-supply-phase power source. The system comprises a phase power supply generator (1), a phase power supply phase compensator (2), a fling-cut switch (3), a controller (4), and a voltage transformation device (5). An output end of the phase power supply phase compensator (2) is connected to a system neutral point by means of the fling-cut switch (3). The system can passively generate power distribution network phase power supply and harmonic phase power supply and input an inverse phase power supply and a harmonic phase power supply into the system according to fault logic. The complete compensation of reactive current, harmonic current and active current for the ground fault of the power distribution network is achieved, the defect that compensation is incomplete by adopting an inversion injection method of a power electronic device after electricity is taken from a bus system is overcome, and the problems that an active inversion method has a poor metallic grounding compensation effect and a conventional arc suppression coil cannot achieve full compensation are solved. The system is efficient and accurate and can completely compensate overvoltage and overcurrent generated by a ground fault, the safety of a power grid and equipment is guaranteed, and the risk of electric shock of a human body is completely avoided.

Description

Ground fault current compensation system, method and device of self-produced power supply phase power supply

This application claims the priority of a Chinese patent application filed with the Chinese Patent Office on October 18, 2019, the application number is 201910992109.0, and the invention title is "A ground fault current compensation system and method for self-produced power supply phase power supply", all of which The content is incorporated in this application by reference.

Technical field

The invention relates to the technical field of power distribution networks, and in particular to a ground fault current compensation system, method and device for self-produced power supply phase power.

Background technique

Single-phase ground faults in domestic and foreign power distribution networks account for more than 80%, which seriously affect the safe operation of power grids and equipment. Safe handling of ground faults plays an important role in social and economic development. When the capacitive current of the system is greater than 10A, the arc suppression coil grounding method is adopted. The arc suppression coil can reduce the fault current to a certain extent. The system can run for 2 hours with faults, but the arc suppression coil cannot achieve full compensation. There is still a residual current less than 10A at the fault point. The existence of residual current can cause personal electric shock and fire accidents. , And seriously threaten the safe and stable operation of power grids and equipment. When the capacitive current of the system is large, the grounding method of small resistance is mostly adopted. When a single-phase grounding fault occurs, the zero-sequence current of the faulted line is amplified, and the relay protection device quickly cuts off the faulted line, but the reliability of the power supply of this grounding method is difficult to guarantee , And there is a risk that the relay protection will refuse to operate when high resistance is grounded.

At present, in order to completely eliminate the single-phase ground fault hazard, while ensuring the reliability of power supply. Many methods for fully compensating the single-phase ground fault current have been proposed at home and abroad.

Swedish Neutral published "Application of Ground Fault Neutralizer Full Compensation Technology", which discloses a method of injecting current into the neutral point of the system through an active compensator to compensate the current at the ground fault point. But the ground fault residual current in this method cannot be directly obtained. The residual current value is calculated by the system's ground distribution parameters, and the deviation is large. At the same time, the compensator uses power electronic devices to control the current phase and amplitude. The accuracy of the value cannot be guaranteed at the same time, and the compensation current has a large harmonic content, complex control, and poor stability; therefore, the compensation effect of the GFN (ground fault neutralizer) manufactured by Swedish Neutral is greatly deviated from the ideal value. The device is located in a certain place in Zhejiang. The results of the simulation test show (the field test study of fault line selection based on neutral point full compensation technology "Zhejiang Electric Power" 2018 04), for metallic ground faults, the ground residual current after compensation by the GFN device is still above 5A , And the ideal value, that is, the zero current has a large gap, which is only equivalent to the compensation effect of the arc suppression coil.

Domestically, the patent CN102074950A discloses a method of arc suppression and protection for a ground fault in a distribution network, which is similar to the Swedish Neutral arc suppression method. The fault phase voltage is suppressed to zero by injecting current into the neutral point of the distribution network. When this method has metallic grounding, the fault phase voltage is 0. How to control the fault voltage to 0? This method is only for high-resistance grounding faults. It is effective, and to control the faulty phase voltage, it is necessary to accurately control the amplitude and phase of the injected current, which is difficult to achieve.

The patent application number 201710550400.3 discloses an active step-down safe handling method for ground faults of ineffective grounding systems. This method sets taps on the side windings of the transformer system, and reduces faults by short-circuiting the taps of the faulty phase windings to the ground or through impedance. Phase voltage to achieve the purpose of limiting the current at the ground fault point. Essentially, this method is to create another grounding point on the bus side of the system when single-phase grounding occurs in the grid line to shunt the original single-phase grounding current. Obviously, this method has a poor compensation effect for metallic single-phase grounding faults. It is even invalid, and the malfunction of the device will cause a short circuit between phases.

The patents with the application number 201710544978.8 and the application number 201710544976.9 disclose the method of step-down arc suppression for the ground fault phase of the non-effective grounding system. Both methods are in the case of a single-phase ground fault. An external power supply is added between the line and the ground, or the neutral point and the ground, or the tap tap of the side winding of the neutral point ineffective grounding system and the ground, in order to reduce the fault voltage. The difference between the two methods is that one of the external power sources is a voltage source, and the other is a current source, so there is no essential difference. There are also the problem of phase voltage accuracy of the control system of the voltage source and the current source, and when the metal is short-circuited, the phase-to-ground voltage is zero and cannot be controlled. In the implementation of the two methods, if the external power supply is directly applied to the bus or between the line and the ground, the system line voltage will be changed, causing the system load (such as the distribution transformer) to fail to operate normally.

In summary, in the prior art, there is no simple control, accurate and efficient single-phase ground fault current full compensation method, which can take into account the power supply reliability and safety of the power distribution system.

Summary of the invention

In view of this, the purpose of the present invention is to provide a ground fault current compensation system, method and device for self-produced power supply phase power supply, which converts the line power supply on the bus into a reverse phase power supply through a line-to-phase converter, combined with switching The neutral point of the switch access system is connected to the fault phase to suppress the overvoltage of the fault phase to achieve the purpose of full compensation, which effectively solves the problems of complicated current control in the single-phase grounding fault of the power distribution system and the difficulty of complete compensation for metallic grounding. At the same time, the system is also equipped with a voltage transformation device to adjust the voltage of the line power supply after the phase-changing power supply, so as to achieve the purpose of full current and voltage compensation when a ground fault occurs. After the full compensation of the present invention, no arc occurs, avoiding the risk of personal electric shock and improving Improve power supply reliability and power supply security.

The present invention solves the above technical problems through the following technical means:

On the one hand, the present invention provides a ground fault current compensation system for self-produced power supply phase power, including a phase power supply generator, a phase power supply phase compensator, a switching switch, a controller, and a voltage transformation device. Compensation capacitor bank (reactor bank) or series capacitor bank (series reactor bank) or voltage regulator. After the phase power supply generator is connected to the bus, the output terminal is connected to the input terminal of the power supply compensator, and the output terminal of the phase power supply phase compensator is connected to the neutral point of the system through a switching switch. The output end of the phase compensator of the phase power supply will obtain a voltage with the opposite phase and the same amplitude as the power supply voltage of the grid system, and this voltage can fully compensate the current at the ground fault point.

Further, the lead-out point of the primary winding of the phase power supply generator is connected to the busbar of the grid system; the lead-out point of the secondary winding of the phase power supply generator is respectively connected with the corresponding phase connection point of the primary winding of the phase power supply phase compensator.

The secondary windings of the phase compensator of the phase power supply are respectively provided with a phase A compensation connection point, a phase B compensation connection point, a phase C compensation connection point and a neutral point n; the neutral point of the phase compensator of the phase power supply The lead point n should be grounded.

Further, the switching switch is provided with an A-phase switch connection point, a B-phase switch connection point, a C-phase switch connection point, and a common connection point.

Further, the phase A compensation connection point, the B phase compensation connection point, and the C phase compensation connection point of the secondary winding of the phase power supply phase compensator are respectively connected to the A phase switch connection point, the B phase switch connection point, and C of the switching switch. Phase switch connection point.

Further, the system line voltage is converted into phase voltage by the phase power supply generator to generate the power supply phase power. The connection form of the phase power supply generator can be Dy or Zy or Yd or Yy, etc., but when the phase power supply generator secondary winding When the neutral point is led out, it must not be grounded. According to the transformer principle, there is a phase difference between the power supply phase power generated by the phase power supply generator and the power supply phase voltage of the grid system.

And

among them

Is the phase difference between the line voltage of the phase power supply generator and the corresponding line voltage of the grid system, n is an integer in the range of [0,11].

Further, the rated voltage of the phase power supply generator has no principle conflict or influence on the realization of the present invention, but considering the existing mature technology and more convenient implementation of this technology, the recommended rated line voltage of the secondary winding of the phase power supply generator 0.4kV or above, and within the rated voltage of the grid system. But the voltage ratio of the primary winding and the secondary winding of the phase power generator is k.

The phase power supply phase compensator compensates the phase voltage phase difference generated by the phase power supply generator; its connection form can be Dyn or Zyn or Yyn, and its y neutral point must be grounded. There is a phase difference between the output line voltage and the input line voltage

The rated voltage of the primary winding of the phase power supply phase compensator is the rated voltage of the secondary winding generated by the phase power supply, the rated line voltage of the secondary winding of the phase power supply phase compensator is the rated voltage of the grid system, and the voltage ratio of the primary winding and the secondary winding Is 1/k.

Furthermore, in order to implement this technology more conveniently, Table 1 shows the connection groups that can be used by some phase power supply generators and the connection groups that should be used by the corresponding phase power supply phase compensator.

Table 1 Some phase power supply generators can use the connection groups used by the phase power supply phase compensator

Further, the switching switch is a fast switching switch such as a mechanical switch and a power electronic switch.

Further, when the phase power supply generator and the phase power supply phase compensator output the compensation current, a voltage drop is generated in the internal impedance of the phase power supply generator and the phase power supply phase compensator, so that the output terminal of the phase power supply phase compensator (ie The voltage amplitude obtained by the neutral point) will be lower than the voltage amplitude of the power supply of the grid system. Therefore, this technical solution is equipped with a voltage transformation device, and the voltage drop generated when the phase compensator of the phase power supply phase compensator outputs the compensation current is appropriately adjusted through the voltage transformation device. Adjust so that the voltage amplitude obtained at the output terminal (ie neutral point) of the phase compensator is equal to the phase voltage amplitude of the system power supply.

Further, this technology provides three different implementation methods for the solution to achieve voltage transformation, which can be selected arbitrarily in the specific implementation. The voltage transformation device is a compensation capacitor bank (reactor bank), a series capacitor bank (series reactor bank) or a voltage regulator.

Further, when the voltage transformation device is a compensation capacitor bank (reactor bank),

The compensation capacitor bank is a group of delta-connected capacitor banks connected to the three-phase output end of the secondary winding of the phase compensator of the phase-to-phase power supply. The compensation capacitor bank is delta-connected, and its leading ends are respectively connected to the phases of the phase power supply. A phase compensation connection point, B phase compensation connection point, and C phase compensation connection point on the secondary side of the compensator.

The capacitor capacity of each phase of the parallel voltage regulating capacitor bank can be calculated as follows:

C is the series regulating capacitor, ω is the angular frequency of the grid system, and Z _L is the equivalent leakage reactance of the phase power supply generator and the phase power supply phase regulator.

Further, when the voltage transformation device is a series capacitor bank (series reactor bank):

The series regulating capacitor is connected in series between the common connection point of the switching switch and the neutral point of the grid system. The common connection point of the switching switch is connected to one end of the primary winding of the series capacitor bank, and the other end of the primary winding of the series capacitor bank is grounded. One end of the secondary secondary winding of the series capacitor bank is connected to the neutral point of the system, and the other end of the secondary side is grounded.

Its electric capacity can be calculated as follows:

Among them, C is a series regulating capacitor, ω is the angular frequency of the grid system, and Z _L is the equivalent leakage reactance of the phase power supply generator and the phase power supply phase regulator.

Further, when the transformer device is a voltage regulator, the common connection point of the switching switch is connected to one end of the primary winding of the voltage regulator, the other end of the primary winding of the voltage regulator is grounded, and one end of the secondary and secondary winding of the voltage regulator is connected to the system The neutral point is connected, and the other end of the secondary side is grounded. The voltage regulator is connected in series between the common connection point of the switching switch and the neutral point of the grid system, and the voltage regulator is used to compensate the voltage input to the neutral point of the system, so that the neutral point voltage is equal to the phase voltage amplitude of the system power supply. The voltage transformation device can be any combination of a compensation capacitor bank, a series capacitor bank and a voltage regulator. The voltage transformation device can be any combination of a compensation capacitor bank, a series capacitor bank and a voltage regulator.

Further, the controller mainly includes a fault judgment module and a switch control module.

The fault judgment module judges whether the system has single-phase grounding and the grounding phase according to the system zero sequence voltage, three-phase voltage, line zero sequence current, etc. The switch control module controls the corresponding switch of the switching switch to close according to the grounding phase determined by the fault occurrence judgment module.

On the other hand, the present invention also provides a ground fault current compensation method for self-produced power supply, which is specifically executed as follows:

Judge whether the system has single-phase grounding and determine the grounding phase through the controller;

When a ground fault occurs in a phase, the controller controls the switching switch to close the phase switch corresponding to the fault;

Voltage compensation through transformer device;

When the closing time of the switching switch reaches the set time, the controller controls the switching switch to open;

The controller continues to judge whether the single-phase ground fault exists;

If the ground fault still exists, the controller controls the switching switch to close the phase switch corresponding to the fault. If the single-phase grounding does not exist, the single-phase grounding compensation process ends.

Further, the opening time of the switching switch is set according to the line working conditions, for example, the opening time is set according to the condition that there are many ground faults in the tree barrier of the line or other ground faults.

In another aspect, the present invention also provides a ground fault current compensation device for self-produced power supply phase power supply, including:

The fault judgment module is used to judge whether the system has single-phase grounding and judge the grounding phase;

Switch control module, used to control the switching switch to close the phase switch corresponding to the fault when a ground fault occurs in a certain phase;

Voltage compensation module, used for voltage compensation through the transformer device;

The switch control module is also used to control the switching switch to open when the closing time of the switching switch reaches the set time;

The fault judgment module is also used to continue to judge whether a single-phase ground fault exists;

The switch control module is also used to control the switching switch to close the phase switch corresponding to the fault if the ground fault still exists, and if the single-phase grounding does not exist, the single-phase grounding compensation process ends.

The present invention firstly proposes to pass the line voltage that remains unchanged before and after the single-phase grounding in the system through the phase power supply generator; the phase power supply phase compensator transforms the phase power supply of the system power supply to compensate for the single-phase grounding of the system. Active power and reactive power formed by ground impedance. To achieve the complete compensation purpose of suppressing the voltage and current of the single-phase ground fault point to zero. Under single-phase grounding faults, the system can run with power, and there is no risk of electric shock or arcing at the single-phase grounding fault point; and the method provided by the present invention only controls the opening and closing of the switch, which greatly simplifies the single-phase grounding fault full compensation technology Control Method.

The beneficial effects of the present invention are:

(1) The technical solution proposed by the present invention obtains a power supply with the phase voltage opposite to the system power supply and the same amplitude from the system through passive components, which can fully compensate the single-phase ground fault current, eliminate grounding arcs, and ensure power supply to the grid system Reliability, avoiding the risk of personal electric shock. Allow the grid system to continuously supply power and improve the safety of power supply.

The compensation system proposed by the present invention can use passive components to obtain components whose phase is opposite to the phase voltage of the power supply of the system fault phase, without phase adjustment, and only need to adjust the voltage amplitude and switch corresponding switches. Compared with the existing active full compensation technology based on power electronic inverter technology, even if the system voltage fluctuates, there is no need to adjust the voltage and phase, its compensation accuracy is higher, the control method is simpler, and it has incomparable technology. Advantage.

(2) In the technical solution provided by the present invention, components that can operate stably for a long time, such as transformers, voltage regulators, capacitors, switches, etc., which are very mature in the prior art, are used, and the stability is significantly better than that of easily damaged power electronic devices; and the maintenance is complicated. Compared with the conventional power electronic inverter power supply, the components used in this technical solution are easy to maintain or even maintenance-free common and mature components of the power system; the components used in this technical solution have mature technology and low cost; therefore, they are comparable to existing power electronic components. Compared with the source full compensation technology, the hardware cost, R&D cost and maintenance cost in the implementation of this technical solution are relatively low, and the stability is high, and the maintenance cost is low.

Description of the drawings

In order to explain the technical solution of the present application more clearly, the following will briefly introduce the drawings needed in the embodiments. Obviously, for those of ordinary skill in the art, without creative work, Other drawings can be obtained from these drawings.

Figure 1 is a schematic diagram of a ground fault current compensation system for self-produced power supply of the present invention;

2 is a schematic diagram of the compensation voltage structure of a series capacitor bank of a self-produced power supply ground fault current compensation system of the present invention;

3 is a schematic diagram of the compensation voltage structure of the compensation capacitor bank of a ground fault current compensation system of self-produced power supply of the present invention;

4 is a schematic diagram of the voltage regulator compensation voltage structure of a self-produced power supply ground fault current compensation system of the present invention;

Fig. 5 is a schematic diagram of the generation and conversion process of the phase power supply of the present invention;

Fig. 6 is a flow chart of a ground fault current compensation method for self-produced power supply of the present invention;

Among them: phase power supply generator 1, phase power supply phase compensator 2, switching switch 3, controller 4, transformer device 5, compensation capacitor bank (compensation reactor) 51, series capacitor bank (series reactor bank) 52. Voltage regulator 53 and line-to-phase converter 6.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present application, not all of the embodiments. Based on the embodiments of the present application, those of ordinary skill in the art All other embodiments obtained without creative work are within the protection scope of this application.

As shown in Fig. 1, the ground fault current compensation system, method and device of the self-produced power supply phase power supply of the present invention are shown in Fig. 1:

In this embodiment, referring to FIGS. 2-4, a typical embodiment is given; it includes a phase power supply generator 1, a phase power supply phase compensator 2, a switching switch 3, a controller 4, and a voltage transformer 5.

Phase power supply generator 1 is a Dy11-connected transformer, connected to the bus bar to convert the bus line voltage into phase voltage; Phase power supply phase compensator 2 is a Dyn7-connected transformer, connected to the phase power supply generator 1 is used to compensate the phase; the switching switch 3 is connected to the phase compensator 2 of the phase power supply, and the switching is controlled by the controller 4.

In this embodiment, the controller 4 is used to control the switching of the switching switch 3 and determine the fault phase;

In this embodiment, one end of the transformer device 5 is connected to the switching switch 3, and the other end is connected to the neutral point of the bus bar.

In this embodiment, the bus power supply line voltages are respectively U _AB , U _BC , U _CA , and the bus power supply phase voltages are U _A , U _B , U _{C, respectively} ; the line voltages output by the phase power supply generator 1 are recorded respectively U _ab1 , U _bc1 , U _ca1 , and the phase voltages are U _a1 , U _b1 , U _c1 , respectively. According to the transformer principle, Dy11 connects the transformers of the group, and the secondary side line voltage is 30° ahead of the primary side voltage, that is, the busbar voltage After being transmitted by the phase power supply generator 1, the busbar voltages U _AB , U _BC and U _{CA are} converted into phase voltages U _a1 , U _b1 , U _c1 , and the phase angles of _{U ab1} , U _bc1 , and U _ca1 _{respectively lead U AB} , U _BC , U _CA angle 30° as formula 1:

The voltage ratio of the primary winding to the secondary winding of the phase power supply generator 1 is k; therefore, there is formula 2:

The line voltage output by the phase compensator 2 of the phase- _indicating power supply is U ab2, U _bc2 , U _ca2 , and the phase voltages are U _a2 , U _b2 , U _{c2 respectively} . According to the transformer principle, Dyn7 connects the transformers of the group, and the secondary side line voltage It lags behind the primary side line voltage by 210°, that is, the phase angles of _{U ab2} _{, U bc2} , and U _ca2 _{lag behind U ab1} , U _bc1 , U _{ca1 by} 210° respectively, which can be expressed as formula 3:

The voltage ratio of the primary winding to the secondary winding of the phase power supply phase compensator 2 is 1/k, so as Equation 4:

According to formula 1 and formula 3, formula 5 can be obtained:

According to formula 2 and formula 4, formula 6 can be obtained:

Further, it can be seen from formula 7:

In this embodiment, the busbar voltages U _AB , U _BC , and U _CA are transmitted through the phase power supply generator 1 and the phase power supply phase compensator 2, and the phases of U _ab2 , U _bc2 and U _{ca2 are} opposite. Therefore, the phases of the busbar side of the system The power supply voltages U _A , U _B , and U _{C are} _{opposite in phase to U a2} , U _b2 , and U _c2 transmitted by the phase power supply generator 1 and the phase power supply phase compensator 2, and the amplitudes are equal. If phase A single-phase grounding occurs in the system, close the phase A switch of switching switch 3, U _{a2 will} be the neutral point voltage U ₀ through the transformer 5, U ₀ and U _{A are} opposite in phase, with equal amplitude, and natural output The active and reactive power that needs to be compensated. Therefore, the ground-to-ground voltage is zero, the system ground phase voltage is zero, and the ground point current is also zero, achieving the purpose of fully compensating the ground current and ensuring the reliability and safety of power supply.

In this embodiment, refer to FIG. 5 for a schematic diagram of voltage phase changes during the generation and conversion of the phase power supply of the present invention. After the busbar voltage is transmitted by the phase power supply generator 1, the busbar voltages U _AB , U _BC , U _{CA are} converted into phase voltages U _a1 , U _b1 , U _c1 , and the phase angles of _{U ab1} , U _bc1 , U _{ca1 are respectively} _{The angles of U AB} , U _BC , and U _{CA are} advanced by 30°. After further passing through the phase power supply phase compensator 2, U _a2 , U _b2 , U _c2 and the system bus side phase power supply voltage U _A , U _B , U _{C have} opposite phases.

The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced. Without departing from the purpose and scope of the technical solution of the present invention, it should be covered in the scope of the claims of the present invention. The technologies, shapes, and structures that are not described in detail in the present invention are all known technologies.

Claims

A ground fault current compensation system for self-produced power supply phase power supply, characterized in that it comprises a line-to-phase converter (6), a switching switch (3), and a controller (4). The line-to-phase converter (6) and After the busbar is connected, it is connected to the neutral point of the system through the switching switch (3). The input terminal of the controller (4) is connected with the voltage transformer of the busbar, and the output terminal of the controller (4) is connected with the switching switch (3) The input terminal is connected.
The ground fault current compensation system for self-produced power supply phase power supply according to claim 1, characterized in that: the ground fault current compensation system for self-produced power supply phase power supply further comprises a voltage transformer (5).
The ground fault current compensation system for self-produced power supply phase power according to claim 1, characterized in that: the line-to-phase converter (6) comprises a phase power supply generator (1) and a phase power supply phase compensator (2) The input end of the phase power supply generator (1) is connected to the grid system bus, and the output end of the phase power supply generator (1) is connected to the input end of the phase power supply phase compensator (2) , The output terminal of the phase power supply phase compensator (2) is connected with the input terminal of the switching switch (3).
The ground fault current compensation system for self-produced power supply phase power according to claim 3, characterized in that: the connection form of the phase power supply generator (1) is in the form of Dy or Zy or Yd or Yy, so The connection form of the phase compensator (2) of the phase power supply is Dyn or Zyn or Yyn.
The ground fault current compensation system of self-produced power supply phase power supply according to claim 2, characterized in that: the voltage transformation device (5) is a compensation capacitor bank or a reactor bank (51), and the compensation capacitor bank Or the reactor group (51) and the phase power supply phase compensator (2) are connected in a delta or star shape.
The ground fault current compensation system of self-produced power supply phase power supply according to claim 2, characterized in that: the voltage transformation device (5) is a series capacitor bank or a series reactor bank (52), and the series capacitor The group or series reactor group (52) is connected in series between the switching switch (3) and the neutral point of the system.
The ground fault current compensation system of self-produced power supply phase power supply according to claim 2, characterized in that: the voltage transforming device (5) is a voltage regulator (53), and the voltage regulator (53) is in series Connected between the switching switch (3) and the neutral point of the system.
The ground fault current compensation system of self-produced power supply phase power supply according to claim 1, characterized in that: the switching switch (3) can be a mechanical switch or a power electronic quick switching switch.
A ground fault current compensation method for self-produced power supply phase power, which is characterized by comprising the following steps:

Judge whether the system has single-phase grounding and determine the grounding phase through the controller;

When a ground fault occurs in a phase, the controller controls the switching switch to close the phase switch corresponding to the fault;

Voltage compensation through transformer device;

When the closing time of the switching switch reaches the set time, the controller controls the switching switch to open;

The controller continues to judge whether the single-phase ground fault exists;

If the ground fault still exists, the controller controls the switching switch to close the phase switch corresponding to the fault. If the single-phase grounding does not exist, the single-phase grounding compensation process ends.
The ground fault current compensation method of self-produced power supply phase power supply according to claim 9, wherein the time when the switching switch is turned off is set according to the line working condition.
A ground fault current compensation device for self-produced power supply phase power, which is characterized in that it comprises:

The fault judgment module is used to judge whether the system has single-phase grounding and judge the grounding phase;

Switch control module, used to control the switching switch to close the phase switch corresponding to the fault when a ground fault occurs in a certain phase;

Voltage compensation module, used for voltage compensation through the transformer device;

The switch control module is also used to control the switching switch to open when the closing time of the switching switch reaches the set time;

The fault judgment module is also used to continue to judge whether a single-phase ground fault exists;

The switch control module is also used to control the switching switch to close the phase switch corresponding to the fault if the ground fault still exists, and if the single-phase grounding does not exist, the single-phase grounding compensation process ends.