CN111769534A - Voltage adjusting method and device of power supply ground fault current compensation system - Google Patents
Voltage adjusting method and device of power supply ground fault current compensation system Download PDFInfo
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Abstract
The present disclosure relates to the field of power equipment manufacturing technologies, and in particular, to a voltage regulation method and device for a power ground fault current compensation system. The problem that a voltage regulator transformation ratio obtaining method in the prior art is lacked can be solved to a certain extent, and single-phase earth fault current full compensation is achieved through a line phase converter and a voltage regulator. The method comprises the following steps: on the basis of a phase power supply ground fault arc extinguishing principle, the sequence components of primary side current and fault phase current of a voltage regulator are reduced to the secondary side of a linear phase converter to obtain the sequence components of the fault phase of the secondary side of the linear phase converter; obtaining a relation equation set among the transformation ratio of the voltage regulator, the leakage reactance of the line phase converter, the leakage reactance of the voltage regulator and the load impedance by establishing a composite sequence network diagram of the secondary side of the line phase converter; and calculating to obtain the transformation ratio of the voltage regulator based on the relation equation set.
Description
Technical Field
The present disclosure relates to the field of power equipment manufacturing technologies, and in particular, to a voltage adjustment method and device for a power ground fault current compensation system.
Background
The compensation of the earth fault current of the power distribution network power system refers to that when the power system in the power grid has a single-phase earth fault, the fault current is reduced to a certain extent through the earth operation of the arc suppression coil, the system can operate for a period of time with faults, but the arc suppression coil cannot realize full compensation, the residual current smaller than 10A still exists at a fault point, the problems of personal electric shock, fire accidents and threat to the safety and stability of power grid equipment can be caused, and therefore the compensation is performed through a mode of amplifying the zero sequence current of a fault line, and the fault line is cut off quickly by the relay protection device. Data show that single-phase earth faults of power distribution networks at home and abroad account for more than 80% of the total number of the power grid faults, the safe operation of the power grid and equipment is seriously influenced, and the safe processing of the earth faults has important effects on social and economic development.
Among some methods for implementing ground fault current compensation, Swedish network published "application of full compensation technique for ground fault neutralizer" discloses a method for compensating ground fault point current by injecting current to system Neutral point through active compensator. However, the residual current of the ground fault in the method can not be directly obtained, and the residual current value is calculated by adopting the ground distribution parameters of the system, so that the deviation is large; meanwhile, the compensator adopts a power electronic device to realize the control of the current phase and the amplitude, the accuracy of the current phase and the amplitude cannot be simultaneously ensured, and the compensation current has large harmonic content, complex control and poor stability. Therefore, the compensation effect of the GFN (ground fault neutralizer) manufactured by Swedish Neutral in sweden deviates greatly from the ideal value, and the results of simulation tests performed by the device at a place in the zhejiang show that for metallic ground faults, the ground residual current compensated by the GFN device is still above 5A, has a large difference from the ideal value, namely zero current, and is only equivalent to the compensation effect of the arc suppression coil.
Patent CN102074950A discloses a method for extinguishing and protecting the arc of a ground fault of a power distribution network, which is similar to the arc extinguishing method of Swedish Neutral, sweden. The method only has the effect on high-resistance grounding faults, controls the fault phase voltage, needs to accurately control the amplitude and the phase of the injected current, and is difficult to realize.
The patent with application number 201710550400.3 discloses an active voltage reduction safety processing method for the ground fault of a non-effective grounding system, which is characterized in that a tap joint is arranged on a side winding of a transformer system, and the voltage of a fault phase is reduced by short-circuiting the tap joint of a fault phase winding to the ground or by short-circuiting through impedance, so that the purpose of limiting the current of a ground fault point is achieved. Essentially, when a power grid line is subjected to single-phase grounding, another grounding point is manufactured on the system bus side to shunt the original single-phase grounding current, obviously, the compensation effect of the method on the metallic single-phase grounding fault is poor or even ineffective, and the inter-phase short circuit is caused by the misoperation of the device.
The patent application numbers 201710544978.8 and 201710544976.9 disclose phase-down arc suppression methods for an ineffective grounding system, both of which apply power between a bus on the ineffective grounding system side and ground, or between a line and ground, or between a neutral point and ground, or between a tap of a winding on the ineffective grounding system side and ground when a single-phase grounding fault occurs, so as to reduce the fault voltage. The difference between the two methods is that one of the external power supplies is a voltage source, and the other external power supply is a current source, so that the two methods have no essential difference. The method also has the problems of the phase voltage precision of a control system of a voltage source and a current source and the problem of incapability of controlling the control system when the relative ground voltage is zero in the case of metallic short circuit. In both methods, when an external power source is applied directly between the bus or line and ground, the system line voltage is changed, and the system load (such as a distribution transformer) cannot operate normally.
The patent application nos. CN201910992389.5 and CN201910992110.3 provide methods for realizing single-phase earth fault current full compensation by using a phase power supply converter and a voltage regulator, but the above two patent technologies do not provide methods for calculating and adjusting the transformation ratio of the voltage regulator when the voltage regulator is used as a voltage regulator.
Disclosure of Invention
The voltage regulator is used as a voltage regulator, and an acquisition method of the transformation ratio of the voltage regulator is provided, so that the problem of the missing of the original technical regulation method can be solved to a certain extent, and the implementation of a self-generated phase power supply ground fault current compensation system is supplemented and supported.
The embodiment of the application is realized as follows:
a first aspect of an embodiment of the present application provides a voltage regulation method for a power supply ground fault current compensation system, including:
on the basis of a phase power supply ground fault arc extinguishing principle, the sequence components of primary side current and fault phase current of a voltage regulator are reduced to the secondary side of a linear phase converter to obtain the sequence components of the fault phase of the secondary side of the linear phase converter;
obtaining a relation equation set among the transformation ratio of the voltage regulator, the leakage reactance of the line phase converter, the leakage reactance of the voltage regulator and the load impedance by establishing a composite sequence network diagram of the secondary side of the line phase converter;
and calculating to obtain the transformation ratio of the voltage regulator based on the relation equation set.
Optionally, the system of relational equations is represented as:
wherein: n is the transformation ratio of the voltage regulator, m is the transformation ratio of the linear phase transformer, ZLIs a load impedance, XT21Equivalent leakage reactance, XT, reduced to the primary side of the voltage regulator11The equivalent leakage reactance to the primary side of the line-to-phase converter is reduced.
Optionally, the line-to-phase converter is configured in particular as a three-phase transformer in the form of a Y/Y junction.
Optionally, the voltage of the fault current compensation system, the droop value of which is determined by the self-losses of the line phase transformer, the voltage regulator and the load device.
Optionally, the leakage reactance of the line phase converter and the leakage reactance of the voltage regulator are obtained through short circuit tests of the line phase converter and the voltage regulator.
Optionally, after obtaining the voltage regulator transformation ratio by calculation based on the system of relational equations, the method further includes: and setting the voltage regulator transformation ratio to a voltage regulator, and finely adjusting the voltage regulator transformation ratio when the system normally operates to obtain the optimal voltage regulator transformation ratio so as to realize the full compensation reference transformation ratio of the ground fault electric arc.
Optionally, the line-phase converter secondary side fault phase sequence components include: the fault phase positive sequence current of the secondary side of the line phase change converter, the fault phase negative sequence current of the secondary side of the line phase change converter and the fault phase zero sequence current of the secondary side of the line phase change converter.
A second aspect of an embodiment of the present application provides a voltage regulation device of a power supply ground fault current compensation system, including: the present invention relates to a power supply ground fault current compensation system, and more particularly, to a power supply ground fault current compensation system, a memory, a processor and a computer program stored on the memory, wherein the processor executes the computer program to perform the voltage regulation method of any of the power supply ground fault current compensation system in the summary provided by the first aspect of the embodiments of the present application.
A third aspect of the embodiments of the present application provides a computer-readable storage medium, which stores computer instructions, and when at least part of the computer instructions are executed by a processor, the voltage regulation method of the power supply ground fault current compensation system according to any one of the first aspect of the embodiments of the present application is implemented.
The beneficial effect of this application lies in: by calculating the sequence components of the primary side current and the fault phase current of the voltage regulator, the primary side current and the fault phase current can be reduced to the secondary side of the linear phase converter to obtain the sequence components of the fault phase of the secondary side of the linear phase converter; further, by establishing a composite sequence network diagram of the secondary side of the line phase converter, a relation equation set among the transformation ratio of the voltage regulator, the leakage reactance of the line phase converter, the leakage reactance of the voltage regulator and the load impedance can be obtained; the transformation ratio of the voltage regulator is further obtained by calculating a relational equation set, the problem that a transformation ratio method and a device of the voltage regulator in the prior art are lacked can be solved to a certain extent, the voltage drop calculation of a ground fault current compensation system of the self-generated power supply phase power supply can be solved, a theoretical basis is provided for the implementation of the ground fault current compensation system of the self-generated power supply phase power supply, and the support is provided for the complete compensation of the voltage and the current of the ground fault point of the self-generated power supply phase power supply.
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Specifically, in order to more clearly explain the technical solution of the present application, the drawings needed to be used in the embodiments are briefly described below, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without any creative effort.
FIG. 1 shows a schematic diagram of a fault current compensation voltage regulation system 100 of an embodiment of the present application;
FIG. 2 illustrates a schematic diagram of an exemplary computing device 200 in an embodiment of the present application;
FIG. 3 is a schematic diagram illustrating a self-generated power supply ground fault current compensation system according to an embodiment of the present application;
FIG. 4 is a schematic diagram illustrating a flow chart of a voltage regulation method of a power supply ground fault current compensation system according to an embodiment of the present application;
fig. 5 is a schematic diagram illustrating a flow chart of acquiring fault phase sequence components at a secondary side of a linear phase converter according to an embodiment of the present application;
fig. 6 shows a composite sequence diagram of the equivalent leakage reactance, voltage regulator and load impedance of the transformer of the embodiment of the present application normalized to the secondary side of the linear phase transformer;
FIGS. 7A and 7B are schematic equivalent circuit diagrams of composite preface network diagrams of embodiments of the present application;
fig. 8 is a schematic diagram illustrating a process of obtaining a system of relational equations among a transformation ratio of a voltage regulator, a leakage reactance of a line-to-phase converter, a leakage reactance of a voltage regulator, and load impedance according to an embodiment of the present application.
Detailed Description
Certain exemplary embodiments will now be described to provide an overall understanding of the principles of the structure, function, manufacture, and use of the devices and methods disclosed herein. One or more examples of these embodiments are illustrated in the accompanying drawings. Those of ordinary skill in the art will understand that the devices and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments and that the scope of the various embodiments of the present invention is defined solely by the claims. The features illustrated or described in connection with one exemplary embodiment may be combined with the features of other embodiments. Such modifications and variations are intended to be included within the scope of the present invention.
Reference throughout this specification to "embodiments," "some embodiments," "one embodiment," or "an embodiment," or the like, means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases "in various embodiments," "in some embodiments," "in at least one other embodiment," or "in an embodiment" or the like throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Thus, the particular features, structures, or characteristics shown or described in connection with one embodiment may be combined, in whole or in part, with the features, structures, or characteristics of one or more other embodiments, without limitation. Such modifications and variations are intended to be included within the scope of the present invention.
Fig. 1 is a schematic diagram of a fault current compensation voltage regulation system 100 according to some embodiments of the present application. Fault current compensation voltage regulation system 100 is a platform for automatically implementing voltage regulation in a power ground fault current compensation system. Fault current compensation voltage regulation system 100 may include a server 110, at least one storage device 120, at least one network 130, one or more circuit detection devices 150-1, 150-2. The server 110 may include a processing engine 112.
In some embodiments, the server 110 may be a single server or a group of servers. The server farm may be centralized or distributed (e.g., server 110 may be a distributed system). In some embodiments, the server 110 may be local or remote. For example, server 110 may access data stored in storage device 120 via network 130. Server 110 may be directly connected to storage device 120 to access the stored data. In some embodiments, the server 110 may be implemented on a cloud platform. The cloud platform may include a private cloud, a public cloud, a hybrid cloud, a community cloud, a distributed cloud, multiple clouds, the like, or any combination of the above. In some embodiments, server 110 may be implemented on a computing device as illustrated herein, including one or more components of computing device 200.
In some embodiments, the server 110 may include a processing engine 112. Processing engine 112 may process information and/or data related to the service request to perform one or more of the functions described herein. For example, the processing engine 112 may be based on information collected by the acquisition circuit detection device 150 and sent to the storage device 120 via the network 130 for updating data stored therein. In some embodiments, processing engine 112 may include one or more processors. The processing engine 112 may include one or more hardware processors, such as a Central Processing Unit (CPU), an Application Specific Integrated Circuit (ASIC), an application specific instruction set processor (ASIP), an image processor (GPU), a physical arithmetic processor (PPU), a Digital Signal Processor (DSP), a Field Programmable Gate Array (FPGA), a Programmable Logic Device (PLD), a controller, a micro-controller unit, a Reduced Instruction Set Computer (RISC), a microprocessor, or the like, or any combination of the above.
In some embodiments, storage device 120 may be connected to network 130 to enable communication with one or more components in fault current compensation voltage regulation system 100. One or more components of fault current compensation voltage regulation system 100 may access data or instructions stored in storage device 120 via network 130. In some embodiments, storage device 120 may be directly connected to or in communication with one or more components of fault current compensation voltage regulation system 100. In some embodiments, storage device 120 may be part of server 110.
The network 130 may facilitate the exchange of information and/or data. In some embodiments, one or more components in fault current compensation voltage regulation system 100 may send information and/or data to other components in fault current compensation voltage regulation system 100 via network 130. For example, the server 110 may obtain/obtain the request from the circuit detection device 150 via the network 130. In some embodiments, the network 130 may be any one of a wired network or a wireless network, or a combination thereof. In some embodiments, the network 130 may include one or more network access points. For example, the network 130 may include wired or wireless network access points, such as base stations and/or Internet switching points 130-1, 130-2, and so forth. Through the access point, one or more components of fault current compensating voltage regulation system 100 may be connected to network 130 to exchange data and/or information.
The circuit detecting means 150 may include a voltage sensor, a current sensor, a short circuit sensor, and the like. In some embodiments, the circuit detection device 150 may be used to collect data from the circuit. In some embodiments, the circuit detection device 150 may send the collected various data information to one or more devices in the fault current compensated voltage regulation system 100. For example, the data information collected by the circuit testing apparatus 150 may be sent to the server 110 for processing or stored in the storage device 120.
FIG. 2 is a schematic diagram of an exemplary computing device 200 shown in accordance with some embodiments of the present application. The server 110, the storage device 120, and the circuit detection apparatus 150 may be implemented on the computing device 200. For example, the processing engine 112 may be implemented on the computing device 200 and configured to implement the functionality disclosed herein.
For ease of understanding, only one processor is exemplarily depicted in fig. 2. However, it should be noted that the computing device 200 in the present application may include a plurality of processors, and thus the operations and/or methods described in the present application implemented by one processor may also be implemented by a plurality of processors, collectively or independently. For example, if in the present application a processor of computing device 200 performs steps 1 and 2, it should be understood that steps 1 and 2 may also be performed by two different processors of computing device 200, either collectively or independently.
The voltage regulating method and device of the phase power supply ground fault current compensation system can be suitable for self-production power supply grids.
Example 1
Fig. 3 shows a schematic structural diagram of a self-generated power supply ground fault current compensation system according to an embodiment of the present application.
The self-generated power phase power supply ground fault current compensation system comprises: line-to-phase converters and voltage regulators.
The line phase converter can be specifically set as a Y/Y-connected three-phase transformer and is connected in series to the voltage regulator through a phase selection switch. The line phase converter comprises three-phase input and three-phase output, and corresponding phase current is conducted by controlling the phase selection switch.
And the three-phase load of the voltage regulator is respectively connected to the three-phase output of the line phase converter.
The voltage adjusting method of the power supply ground fault current compensation system provided by the application is suitable for the voltage sag calculation of the ground fault current compensation system configured with the structure and capable of generating the power supply phase power supply, and the ground fault occurring on the phase a in the system shown in fig. 3 is taken as an example for explanation.
Fig. 4 shows a schematic flow chart of a voltage regulation method of the power supply ground fault current compensation system according to the embodiment of the present application.
In step 401, based on the principle of arc extinction by phase power supply ground fault, the sequence components of the primary side current and the fault phase current of the voltage regulator are reduced to the secondary side of the linear phase transformer to obtain the sequence components of the fault phase of the secondary side of the linear phase transformer.
According to the arc extinguishing principle of the phase power supply ground fault, the sequence components of the fault phase on the secondary side of the line phase converter can be obtained by integrating the current on the primary side of the voltage regulator and the fault current components thereof on the secondary side of the line phase converter.
Fig. 5 shows a schematic flow chart of acquiring fault phase sequence components at the secondary side of the linear phase converter according to the embodiment of the application.
In step 501, three-phase voltage initial values and fault phase voltage sequence components of the power supply system are obtained based on the single-phase ground fault and in a complete compensation state.
In some embodiments, the initial values of the three-phase voltages of the power supply system are obtained by using a data acquisition device, such as a voltage sensor provided in the power supply system; the real-time data of the power supply system, namely the initial value of the three-phase voltage, can also be called through a data monitoring system of the power supply system.
The initial value of the three-phase voltage of the power supply system is expressed as formula 1:
wherein,
represents the initial voltage of phase a, i.e., the faulted phase voltage;
the initial voltage of the B-phase is shown,
which represents the initial voltage of the C-phase,
represented as the faulted phase supply emf.
The fault phase voltage sequence components comprise: fault phase positive sequence voltage
Negative sequence voltage of fault phase
Fault phase zero sequence voltage
Each sequence component of the fault phase voltage is obtained through decomposition in a symmetrical component method, and is expressed as formula 2:
wherein,
in order for the faulted phase power supply to be electromotive,
in order to be the fault phase positive sequence voltage,
in order to be the fault phase negative sequence voltage,
is the fault phase zero sequence voltage.
In some implementations, the symmetric component method is the basic method of short-circuit current calculation for power systems, and its purpose is to transform a set of asymmetric ABC quantities into three sets of individually symmetric three-phase phasors, called positive, negative and zero sequence quantities, respectively, and power systems are also classified into positive, negative and zero sequence networks. Asymmetric voltage and current quantity generated after an asymmetric fault occurs in a power system can be decomposed into three sequence nets by applying a symmetric component method, the three sequence nets are analyzed in a sequence voltage and current symmetric mode, and then the three sequence nets are synthesized into actual ABC quantity, so that asymmetric fault calculation can be simplified.
When the power system normally operates, the power system can be considered to be symmetrical, namely, three-phase impedances of all elements are the same, the voltages and the currents of the three phases are equal, and the power system has a normal phase sequence. The disruption of the normal operating mode of the power system is primarily related to an asymmetric fault or asymmetric operation of the circuit breaker. Since only individual points in the whole power system have unequal three-phase impedances, a method for directly solving a complex three-phase asymmetric circuit is not generally used, and a simpler symmetric component method is adopted for analysis. The power system can be considered to be three-phase symmetrical when in normal operation, namely, three-phase impedance of each element is the same, three-phase voltage and current are equal, phase difference between phases is also equal, and the power system has sine waveform and normal phase sequence. A symmetrical three-phase AC system can be calculated by using a single-phase circuit. As long as the magnitude of one phase is calculated, the other two phases can be deduced because the modulus of the other two phases is equal to the calculated phase and the phase difference is plus or minus 120 degrees. When three phases are symmetrically short-circuited or broken, the three phases of the alternating current component are symmetrical. Therefore, the inherent symmetry of the system can be utilized, only one phase needs to be analyzed, and the complexity of calculation by phases is avoided. However, when an asymmetric fault such as a single-phase ground short, a two-phase short, and a two-phase ground short, and a single-phase disconnection or a two-phase disconnection occurs in an electric power system, three-phase impedances are different, three-phase voltages and currents are not equal, and a phase difference between phases is not equal. Such three-phase systems cannot analyze only one of the phases and are typically analyzed using a symmetric component method.
In step 502, based on the compensation current of the power system, the sequence components of the primary side current and the fault phase current of the voltage regulator are calculated and reduced to the sequence components of the fault phase of the secondary side of the line phase converter, and the primary side current of the voltage regulator is the same as the secondary side current of the line phase converter.
In some embodiments, the compensation current of the power supply system is set to
As shown in fig. 3, when the primary-side current of the voltage regulator and the secondary-side current of the line-to-phase converter are the same current, A, B, C terms of current respectively represent the following formula 3:
wherein, the A phase current
Is equal to the compensation current
Phase B and phase C currents are 0.
Decomposing the A-phase fault phase current sequence components in a symmetrical component method mode to obtain the A-phase fault phase current sequence components, wherein the method comprises the following steps: the secondary side fault phase positive sequence current of the line phase change converter, the secondary side fault phase negative sequence current of the line phase change converter and the secondary side fault phase zero sequence current of the line phase change converter are expressed as formula 4:
wherein,
is the fault phase positive sequence current of the secondary side of the linear phase converter,
is the fault phase negative sequence current of the secondary side of the linear phase converter,
the fault phase zero-sequence current is the fault phase zero-sequence current of the secondary side of the linear phase converter.
Continuing to refer to fig. 4, by establishing a composite sequence network diagram of the secondary side of the line-phase converter, a relation equation set among the transformation ratio of the voltage regulator, the leakage reactance of the line-phase converter, the leakage reactance of the voltage regulator and the load impedance is obtained.
Fig. 6 shows a composite sequence diagram of the equivalent leakage reactance, voltage regulator and load impedance of the transformer of the embodiment of the present application, which is normalized to the secondary side of the linear phase transformer.
As shown in the figure, the composite sequence network diagram comprises a line phase converter secondary side fault phase positive sequence impedance Z1∑Phase change of wireConverter secondary side fault phase negative sequence impedance Z2∑Line phase converter secondary side fault phase zero sequence impedance Z0∑. And the secondary side fault phase positive sequence current of the line phase converter corresponding to the fault phase positive sequence current
Line phase converter secondary side fault phase negative sequence current
Line phase converter secondary side fault phase zero sequence current
Fig. 7A and 7B show equivalent circuit schematic diagrams of a composite preface network diagram according to an embodiment of the present application.
In the case of the embodiment shown in figure 7A,
the electromotive force of the fault phase is reduced to the electromotive force of the secondary side of the linear phase converter,
for phase A current, z1∑Is a positive sequence impedance.
In the case of the embodiment shown in figure 7B,
the electromotive force of the fault phase is reduced to the electromotive force of the secondary side of the linear phase converter,
is phase A current, X'T11The ratio of the equivalent leakage reactance reduced to the primary side for the linear phase transformer to the square of the transformation ratio of the linear phase transformer m, XT21The equivalent leakage reactance to the primary side is calculated for the voltage regulator.
Fig. 8 is a schematic diagram illustrating a process of obtaining a system of relational equations among a transformation ratio of a voltage regulator, a leakage reactance of a line-to-phase converter, a leakage reactance of a voltage regulator, and load impedance according to an embodiment of the present application.
In step 801, a relational expression of the compensation system voltage, current and impedance is obtained according to a composite sequence diagram structure of the secondary side of the line-phase converter.
In some embodiments, the relationship between voltage, current and impedance in the fault current compensation system is obtained according to a composite sequence network structure of the secondary side of the line-phase converter, which is expressed as formula 5:
wherein:
Z1∑is positive sequence impedance, z2∑Is a negative sequence impedance, Z0∑Zero sequence impedance, m is the transformation ratio of the line phase transformer, and n is the transformation ratio of the voltage regulator;
XT11equivalent leakage reactance, X, reduced to the primary side for a line phase converterT21The equivalent leakage reactance to the primary side is calculated for the voltage regulator;
zLis a load impedance,
Is the secondary side current of the linear phase-change converter.
In step 802, the leakage reactance, the voltage regulator and the load impedance of the linear phase converter are reduced to the secondary side of the linear phase converter, and the secondary side output voltage of the linear phase converter is calculated.
Wherein,
is the secondary side output voltage of the linear phase-change converter, and
Z′L＝ZLn2。
the voltage obtained by the load of the power supply system in the full compensation state is
The secondary side output voltage of the linear phase converter satisfies the following formula 7:
continuing with fig. 4, in step 403, the voltage regulator transformation ratio is obtained by calculation based on the relational equation set, and the unitary quartic equation is solved to obtain the voltage regulator transformation ratio n.
A representation can be obtained as represented by equation 8:
simplification yields equation 9:
the value of the regulator transformation ratio n can be obtained by solving the above equation 8 and equation 9.
Example 2
The present embodiment will describe a calculation process of the voltage regulator transformation ratio of the fault current compensation system with reference to a specific example.
The leakage reactance parameter of the transformer can be obtained by calculation according to the short-circuit impedance voltage of the transformer, the rated capacity of the line phase-change converter in the embodiment is 6MVA, the primary rated voltage and the secondary rated voltage of the line phase-change converter are the same and are 10kV, the percentage of the short-circuit impedance voltage is 1%, the rated transformation ratio of the line phase-change converter is 1, namely m is 1.
Neglecting the direct current resistance, the excitation reactance and the iron loss of the transformer, according to the equivalent circuit of the transformer, the primary side equivalent leakage reactance of the line phase converter is as follows:
wherein, U1EFor a primary rated voltage, U2kIs a secondary rated voltage, I2kGamma is the impedance voltage percentage for the secondary rated current.
The rated capacity of the voltage regulator is 2MVA, and the primary rated voltage is
The percentage of impedance voltage is 1 percent, and the equivalent leakage reactance X of the primary winding of the voltage regulator is obtained by calculationT21＝5Ω。
Load impedance ZL＝-10Ω。
The above parameter values are substituted for formula 11 to obtain:
the above-mentioned unitary quartic equation is solved, and the voltage regulator transformation ratio n is 1.422.
The application also provides a voltage regulation device of the power ground fault current compensation system, which comprises a memory, a processor and a computer program stored on the memory, wherein the processor executes the computer program to execute the voltage regulation method of the power ground fault current compensation system according to the embodiment of the application. The specific implementation method thereof has been shown in the foregoing, and is not described herein again.
The present application also proposes a computer-readable storage medium, which stores computer instructions, and when at least part of the computer instructions are executed by a processor, the voltage regulation method of the power ground fault current compensation system in the above embodiments is implemented.
Moreover, those skilled in the art will appreciate that aspects of the present application may be illustrated and described in terms of several patentable species or situations, including any new and useful combination of processes, machines, manufacture, or materials, or any new and useful improvement thereon. Accordingly, various aspects of the present application may be embodied entirely in hardware, entirely in software (including firmware, resident software, micro-code, etc.) or in a combination of hardware and software. The above hardware or software may be referred to as "data blocks", "modules", "engines", "units", "components", or "systems". Furthermore, aspects of the present application may be embodied as a computer product, comprising computer readable program code, located in one or more computer readable media.
The computer storage medium may comprise a propagated data signal with the computer program code embodied therewith, for example, on baseband or as part of a carrier wave. The propagated signal may take any of a variety of forms, including electromagnetic, optical, etc., or any suitable combination. A computer storage medium may be any computer-readable medium that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. Program code located on a computer storage medium may be propagated over any suitable medium, including radio, cable, fiber optic cable, RF, or the like, or any combination of the preceding.
Computer program code required for the operation of various portions of the present application may be written in any one or more programming languages, including an object oriented programming language such as Java, Scala, Smalltalk, Eiffel, JADE, Emerald, C + +, C #, VB.NET, Python, and the like, a conventional programming language such as C, Visual Basic, Fortran 2003, Perl, COBOL 2002, PHP, ABAP, a dynamic programming language such as Python, Ruby, and Groovy, or other programming languages, and the like. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any network format, such as a Local Area Network (LAN) or a Wide Area Network (WAN), or the connection may be made to an external computer (for example, through the Internet), or in a cloud computing environment, or as a service, such as a software as a service (SaaS).
Furthermore, unless explicitly stated in the claims, the order of processing elements and sequences, the use of alphanumeric characters, or the use of other names described herein is not intended to limit the order of the processes and methods described herein. While various presently contemplated embodiments of the invention have been discussed in the foregoing disclosure by way of example, it is to be understood that such detail is solely for that purpose and that the appended claims are not limited to the disclosed embodiments, but, on the contrary, are intended to cover all modifications and equivalent arrangements that are within the spirit and scope of the embodiments herein. For example, although the system components described above may be implemented by hardware devices, they may also be implemented by software-only solutions, such as installing the described system on an existing server or mobile device.
Similarly, it should be noted that in the preceding description of embodiments of the application, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure aiding in the understanding of one or more of the embodiments. This method of disclosure, however, is not intended to require more features than are expressly recited in the claims. Indeed, the embodiments may be characterized as having less than all of the features of a single embodiment disclosed above.
The entire contents of each patent, patent application publication, and other material cited in this application, such as articles, books, specifications, publications, documents, and the like, are hereby incorporated by reference into this application. Except where the application is filed in a manner inconsistent or contrary to the present disclosure, and except where the claim is filed in its broadest scope (whether present or later appended to the application) as well. It is noted that the descriptions, definitions and/or use of terms in the attached material of this application shall control if they are inconsistent or conflicting with the description of this application.
Claims (9)
1. A method of voltage regulation for a power ground fault current compensation system, comprising:
on the basis of a phase power supply ground fault arc extinguishing principle, the sequence components of primary side current and fault phase current of a voltage regulator are reduced to the secondary side of a linear phase converter to obtain the sequence components of the fault phase of the secondary side of the linear phase converter;
obtaining a relation equation set among the transformation ratio of the voltage regulator, the leakage reactance of the line phase converter, the leakage reactance of the voltage regulator and the load impedance by establishing a composite sequence network diagram of the secondary side of the line phase converter;
and calculating to obtain the transformation ratio of the voltage regulator based on the relation equation set.
2. The voltage regulation method of a power ground fault current compensation system of claim 1, wherein the system of relational equations is represented as:
wherein: n is the transformation ratio of the voltage regulator, m is the transformation ratio of the linear phase transformer, zLIs a load impedance, XT21Equivalent leakage reactance, X, reduced to the primary side of the voltage regulatorT11The equivalent leakage reactance to the primary side of the line-to-phase converter is reduced.
3. A method of voltage regulation of a power ground fault current compensation system according to claim 1, characterized in that the line phase transformer is arranged in particular as a three-phase transformer in the form of a Y/Y junction.
4. The method of claim 1, wherein the voltage of the fault current compensation system has a droop value determined by the loss of the line-to-phase converter, the voltage regulator, and the load device.
5. The voltage regulation method of the power ground fault current compensation system according to claim 1, wherein the leakage reactance of the line phase converter and the leakage reactance of the voltage regulator are obtained by a short circuit test thereof.
6. The method of voltage regulation of a power ground fault current compensation system of claim 1, further comprising, after calculating a voltage regulator transformation ratio based on the system of relational equations:
and setting the voltage regulator transformation ratio to a voltage regulator, and finely adjusting the voltage regulator transformation ratio when the system normally operates to obtain the optimal voltage regulator transformation ratio so as to realize the full compensation reference transformation ratio of the ground fault electric arc.
7. The voltage regulation method of a power ground fault current compensation system of claim 1, wherein the line-to-phase converter secondary side fault phase sequence components include: the fault phase positive sequence current of the secondary side of the line phase change converter, the fault phase negative sequence current of the secondary side of the line phase change converter and the fault phase zero sequence current of the secondary side of the line phase change converter.
8. A voltage regulation device of a power supply ground fault current compensation system, comprising a memory, a processor and a computer program stored on the memory, the processor when executing the computer program performing a traffic data prediction method according to any one of claims 1-7.
9. A computer-readable storage medium, having stored thereon computer instructions, at least some of which, when executed by a processor, implement the method of any one of claims 1-7.
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