Variable-speed pumped storage unit rotor grounding fault positioning method, device and equipment and readable storage medium

Abstract

The invention relates to a variable-speed pumped storage unit rotor grounding fault positioning method, device and equipment and a readable storage medium, and relates to the technical field of variable-speed pumped storage unit relay protection. The method comprises the following steps: acquiring the zero-sequence voltage of the variable-speed pumped storage unit and the phase potential of each phase of rotor winding; the variable-speed pumped storage unit comprises a three-phase rotor winding; constructing a potential distribution function of each phase of rotor winding and a potential distribution diagram of the three-phase rotor winding according to the zero-sequence voltage and the phase potential of each phase of rotor winding; determining a fault phase winding with a fault from the three-phase rotor windings according to the potential distribution diagram of the three-phase rotor windings; constructing a fault positioning optimization model according to the potential distribution function and the zero sequence voltage of the fault phase winding; and according to the fault positioning optimization model, a preset optimization algorithm is adopted to carry out iterative calculation until a preset iteration ending condition is met, and the fault position of the fault phase winding is obtained. By adopting the method, the fault positioning accuracy can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of relay protection for variable speed pumped storage units, and in particular to a method, device, equipment and readable storage medium for locating rotor grounding faults of variable speed pumped storage units. Background Art

[0002] The existing rotor grounding fault location method is mainly applied to synchronous machines using DC excitation, and cannot be applied to variable-speed pumped storage units with a three-phase rotor winding structure, and its winding potential has the characteristics of phase band distribution. Therefore, the traditional stator grounding fault location method of the generator is more valuable for reference. However, the phase distribution law of the variable-speed pumped storage unit is more complicated due to the influence of operating conditions and does not meet the characteristics of a single 60° phase band. In addition, the voltage to the ground cannot be directly measured at the neutral point of its rotor winding. The above reasons make the existing positioning method unable to be directly applied. In addition to the fault location problem, the phase selection problem of the rotor grounding fault is also more complicated, and it is difficult to obtain an accurate fault location. Therefore, the variable-speed pumped storage unit rotor grounding fault location method in the related art has the problem of low fault location accuracy. Summary of the invention

[0003] Based on this, it is necessary to provide a method, device, computer equipment, computer-readable storage medium and computer program product for locating rotor grounding faults of a variable-speed pumped storage unit that can improve the accuracy of fault locating in order to solve the above-mentioned technical problems.

[0004] In a first aspect, the present application provides a method for locating a rotor grounding fault of a variable speed pumped storage unit, comprising:

[0005] Obtaining the zero-sequence voltage of the variable-speed pumped storage unit and the phase potential of each phase rotor winding; the variable-speed pumped storage unit includes the three-phase rotor winding;

[0006] Constructing a potential distribution function of the rotor winding of each phase and a potential distribution diagram of the rotor winding of three phases according to the zero-sequence voltage and the phase potential of the rotor winding of each phase;

[0007] According to the potential distribution diagram of the three-phase rotor winding, a faulty phase winding having a fault is determined from the three-phase rotor winding;

[0008] Constructing a fault location optimization model according to the potential distribution function of the fault phase winding and the zero-sequence voltage;

[0009] According to the fault location optimization model, a preset optimization algorithm is used to perform iterative calculations until a preset iteration end condition is met, thereby obtaining the fault position of the faulty phase winding.

[0010] In one embodiment, the step of obtaining the zero-sequence voltage of the variable speed pumped storage unit and the phase potential of each phase of the rotor winding includes:

[0011] Obtaining voltage measurement values ​​of the rotor windings of each phase;

[0012] Determining the zero-sequence voltage of the variable speed pumped storage unit according to the voltage measurement value of the rotor winding of each phase;

[0013] The phase potential of the rotor winding of each phase is determined according to the voltage measurement value of the rotor winding of each phase and the zero-sequence voltage.

[0014] In one embodiment, constructing a potential distribution function of the rotor winding of each phase according to the zero-sequence voltage and the phase potential of the rotor winding of each phase includes:

[0015] Determining the amplitude, phase and phase angle of the phase potential of the rotor winding of each phase according to the phase potential of the rotor winding of each phase;

[0016] A potential distribution function of the rotor winding of each phase is constructed according to the zero-sequence voltage, the phase potential of the rotor winding of each phase and the corresponding amplitude, phase, and phase belt angle.

[0017] In one embodiment, the potential distribution function of the rotor winding of each phase is constructed according to the zero-sequence voltage, the phase potential of the rotor winding of each phase and the corresponding amplitude, phase, and phase belt angle, and the corresponding formula includes:

[0018]

[0019] in, Characterize the potential distribution function, Characterizes the phase potential of the rotor winding of the i-th phase, Characterizes the amplitude corresponding to the phase potential of the rotor winding of the i-th phase, θ i Characterizing the phase corresponding to the phase potential of the rotor winding of the i-th phase, Characterize the phase band angle, represents the zero-sequence voltage, and α represents the location where the fault occurs.

[0020] In one embodiment, constructing a potential distribution diagram of the three-phase rotor winding according to the zero-sequence voltage and the phase potential of each phase of the rotor winding includes:

[0021] Determine the zero-sequence voltage phasor and the phase potential phasor of the rotor winding of each phase according to the zero-sequence voltage and the phase potential of the rotor winding of each phase;

[0022] According to the zero-sequence voltage phasor, an auxiliary line lagging the zero-sequence voltage by 90 degrees is determined;

[0023] A potential distribution diagram of the three-phase rotor winding is constructed according to the zero-sequence voltage phasor, the phase potential phasor of each phase of the rotor winding and the auxiliary line.

[0024] In one embodiment, the step of determining a faulty phase winding having a fault from the three-phase rotor windings according to the potential distribution diagram of the three-phase rotor windings includes:

[0025] According to the potential distribution diagram of the three-phase rotor winding, the rotor winding whose phase potential phasor is in a cross relationship with the auxiliary line is determined as the faulty phase winding.

[0026] In one embodiment, the fault location optimization model is constructed according to the potential distribution function of the fault phase winding and the zero-sequence voltage, and the corresponding formula includes:

[0027]

[0028] Among them, α represents the fault location, f(α) represents the objective function, Characterize the zero-sequence voltage, A potential distribution function characterizing the faulty phase winding.

[0029] In a second aspect, the present application also provides a variable speed pumped storage unit rotor grounding fault locating device, comprising:

[0030] An electrical parameter acquisition module, used to acquire the zero-sequence voltage of a variable-speed pumped storage unit and the phase potential of each phase rotor winding; the variable-speed pumped storage unit includes three-phase rotor windings;

[0031] A potential distribution determination module, configured to construct a potential distribution function of the rotor winding of each phase and a potential distribution diagram of the rotor winding of three phases according to the zero-sequence voltage and the phase potential of the rotor winding of each phase;

[0032] A fault phase determination module, used to determine a faulty phase winding having a fault from the three-phase rotor windings according to a potential distribution diagram of the three-phase rotor windings;

[0033] A model building module, used to build a fault location optimization model according to the potential distribution function of the fault phase winding and the zero-sequence voltage;

[0034] The fault location module is used to perform iterative calculations according to the fault location optimization model using a preset optimization algorithm until a preset iteration end condition is met, thereby obtaining the fault position of the fault phase winding.

[0035] In a third aspect, the present application further provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the following steps are implemented:

[0036] Obtaining the zero-sequence voltage of the variable-speed pumped storage unit and the phase potential of each phase rotor winding; the variable-speed pumped storage unit includes the three-phase rotor winding;

[0037] Constructing a potential distribution function of the rotor winding of each phase and a potential distribution diagram of the rotor winding of three phases according to the zero-sequence voltage and the phase potential of the rotor winding of each phase;

[0038] According to the potential distribution diagram of the three-phase rotor winding, a faulty phase winding having a fault is determined from the three-phase rotor winding;

[0039] Constructing a fault location optimization model according to the potential distribution function of the fault phase winding and the zero-sequence voltage;

[0040] According to the fault location optimization model, a preset optimization algorithm is used to perform iterative calculations until a preset iteration end condition is met, thereby obtaining the fault position of the faulty phase winding.

[0041] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the following steps are implemented:

[0042] Obtaining the zero-sequence voltage of the variable-speed pumped storage unit and the phase potential of each phase rotor winding; the variable-speed pumped storage unit includes the three-phase rotor winding;

[0043] Constructing a potential distribution function of the rotor winding of each phase and a potential distribution diagram of the rotor winding of three phases according to the zero-sequence voltage and the phase potential of the rotor winding of each phase;

[0044] According to the potential distribution diagram of the three-phase rotor winding, a faulty phase winding having a fault is determined from the three-phase rotor winding;

[0045] Constructing a fault location optimization model according to the potential distribution function of the fault phase winding and the zero-sequence voltage;

[0046] According to the fault location optimization model, a preset optimization algorithm is used to perform iterative calculations until a preset iteration end condition is met, thereby obtaining the fault position of the faulty phase winding.

[0047] In a fifth aspect, the present application further provides a computer program product, including a computer program, which implements the following steps when executed by a processor:

[0048] Obtaining the zero-sequence voltage of the variable-speed pumped storage unit and the phase potential of each phase rotor winding; the variable-speed pumped storage unit includes the three-phase rotor winding;

[0049] Constructing a potential distribution function of the rotor winding of each phase and a potential distribution diagram of the rotor winding of three phases according to the zero-sequence voltage and the phase potential of the rotor winding of each phase;

[0050] According to the potential distribution diagram of the three-phase rotor winding, a faulty phase winding having a fault is determined from the three-phase rotor winding;

[0051] Constructing a fault location optimization model according to the potential distribution function of the fault phase winding and the zero-sequence voltage;

[0052] According to the fault location optimization model, a preset optimization algorithm is used to perform iterative calculations until a preset iteration end condition is met, thereby obtaining the fault position of the faulty phase winding.

[0053] The above-mentioned variable speed pumped storage unit rotor grounding fault location method, device, computer equipment, computer readable storage medium and computer program product obtain the zero-sequence voltage of the variable speed pumped storage unit and the phase potential of each phase rotor winding as the data basis for subsequent fault location, wherein the variable speed pumped storage unit includes a three-phase rotor winding, and further constructs the potential distribution function of each phase rotor winding and the potential distribution diagram of the three-phase rotor winding according to the zero-sequence voltage and the phase potential of each phase rotor winding. The potential distribution function is constructed so that the working state of each winding can be understood more accurately, and the potential distribution visualization of the three-phase rotor winding is helpful for rapid identification and location of faults. And according to the potential distribution diagram of the three-phase rotor winding, the faulty phase winding with a fault is determined from the three-phase rotor winding, so as to realize the visual identification of the faulty phase winding. In addition, a fault location optimization model is constructed based on the potential distribution function and zero-sequence voltage of the faulty phase winding. Finally, based on the fault location optimization model, an iterative calculation is performed using a preset optimization algorithm until the preset iteration end condition is met. The fault position of the faulty phase winding is obtained, which can converge to the optimal solution quickly, shorten the fault analysis time, and quickly provide fault location information, thereby improving the accuracy of fault location. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the drawings required for use in the embodiments of the present application or related technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0055] Figure 1It is a schematic flow chart of a method for locating a rotor grounding fault of a variable speed pumped storage unit in one embodiment;

[0056] Figure 2 A schematic diagram of a process of constructing a potential distribution map in one embodiment;

[0057] Figure 3 It is a flow chart of a method for accurately locating a rotor grounding fault of a variable speed pumped storage unit based on optimization solution in one embodiment;

[0058] Figure 4 is a schematic diagram of phasor diagrams of three faults in one embodiment;

[0059] Figure 5 It is a structural block diagram of a device for locating rotor grounding fault of a variable speed pumped storage unit in one embodiment;

[0060] Figure 6 FIG. 4 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0061] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0062] In one embodiment, Figure 1 As shown, a method for locating rotor grounding faults of variable speed pumped storage units is provided. This embodiment uses the method applied to a terminal as an example for illustration. It can be understood that the method can also be applied to a server, and can also be applied to a system including a terminal and a server, and is implemented through the interaction between the terminal and the server. In this embodiment, the method includes the following steps:

[0063] Step 102, obtaining the zero-sequence voltage of the variable-speed pumped storage unit and the phase potential of each phase rotor winding.

[0064] Among them, the variable speed pumped storage unit includes a three-phase rotor winding. Among them, the variable speed pumped storage unit is a technology commonly used in hydropower stations. It is a power generation equipment that has the functions of regulating the load of the power system and storing energy. It includes a pumping system and an energy storage system. It uses the low-valley electricity in the power system to pump lake water or river water to a high-level reservoir, and then returns the water to the low-level reservoir through the power generation system when needed, thereby generating electricity. Among them, the rotor winding can be the winding of the generator or motor part of the variable speed pumped storage unit.

[0065] Among them, zero-sequence voltage refers to the average value of the voltage of each phase in a three-phase system, which is usually used to analyze the imbalance of the system, or under certain fault conditions such as ground faults, to help determine whether there is an unbalanced current in the system.

[0066] The phase potential may refer to the voltage of each phase winding relative to a reference point (usually a neutral point or ground).

[0067] Optionally, the system obtains electrical parameters of a variable speed pumped storage unit for which ground fault location needs to be performed, and obtains a zero-sequence voltage and a phase potential of each phase rotor winding according to the electrical parameters.

[0068] Step 104: construct a potential distribution function of each phase rotor winding and a potential distribution diagram of the three-phase rotor winding according to the zero-sequence voltage and the phase potential of each phase rotor winding.

[0069] Among them, the potential distribution function is usually expressed as a mathematical function, which is used to describe the potential (voltage) distribution of the winding in space. For each phase, the potential distribution function reflects the potential change at the rotation angle of the rotor (usually expressed in electrical degrees).

[0070] The potential distribution diagram may be a planar distribution diagram of the potential phasors of the rotor windings of each phase.

[0071] Optionally, the system constructs a potential distribution function based on the mathematical relationship between the zero-sequence voltage and the phase potential of each phase rotor winding, and abstracts the zero-sequence voltage and the phase potential of each phase rotor winding into phasors to construct a potential distribution diagram of the three-phase rotor winding.

[0072] Step 106, determining a faulty phase winding from the three-phase rotor winding according to the potential distribution diagram of the three-phase rotor winding.

[0073] The faulty phase winding may be a rotor winding where a ground fault occurs.

[0074] Optionally, the system determines a faulty phase winding from the three-phase rotor winding according to the distribution relationship between the potential of each phase rotor winding and the zero-sequence voltage in the potential distribution diagram of the three-phase rotor winding.

[0075] Step 108: construct a fault location optimization model according to the potential distribution function and zero-sequence voltage of the faulty phase winding.

[0076] The fault location optimization model may be an algorithm model.

[0077] Optionally, the system constructs a fault location optimization model according to the potential distribution function and zero-sequence voltage of the faulty phase winding, wherein the corresponding formula includes:

[0078]

[0079] Among them, α represents the fault location, f(α) represents the objective function, Characterizes the zero sequence voltage, Characterize the potential distribution function of the fault phase winding.

[0080] Step 110 , according to the fault location optimization model, an iterative calculation is performed using a preset optimization algorithm until a preset iteration end condition is met, thereby obtaining the fault location of the faulty phase winding.

[0081] Among them, the preset optimization algorithm can be the Aurora Optimization Algorithm, which is an optimization algorithm based on natural phenomena and bioinspiration. It imitates the behavior of the aurora in the Earth's magnetic field, and designs search and optimization strategies based on this. The algorithm aims to solve high-dimensional, nonlinear and complex optimization problems, and is usually widely used in science, engineering, artificial intelligence and other fields.

[0082] The fault location may be a specific location where the fault occurs in the faulty phase winding.

[0083] Optionally, the system adopts a preset optimization algorithm according to the fault location optimization model. In the initialization stage, an initial population of decision variables (fault locations) is generated based on pseudo-random numbers. In the rotational motion stage, Lorentz magnetic force is used to describe the interaction between charged particles and the earth's magnetic field to realize the fitness evaluation of different decision variables. The fitness is calculated by the fault location optimization model. In the aurora ellipse trail stage, the phenomenon of charged particles entering the optimal orbit is described to realize different decision variables to find the local optimum or optimize the local structure of the current solution. In the particle collision stage, the chaotic collision between charged particles is described to leave the local optimum to realize the final global optimization. When the number of iterative calculations of the fitness during the particle collision process reaches a preset threshold, the preset iteration end condition is met to obtain the optimal decision variable (fault location), thereby obtaining the fault location of the faulty phase winding.

[0084] In the above-mentioned variable speed pumped storage unit rotor grounding fault location method, the zero-sequence voltage of the variable speed pumped storage unit and the phase potential of each phase rotor winding are obtained as the data basis for subsequent fault location, wherein the variable speed pumped storage unit includes a three-phase rotor winding, and further based on the zero-sequence voltage and the phase potential of each phase rotor winding, the potential distribution function of each phase rotor winding and the potential distribution diagram of the three-phase rotor winding are constructed, and the potential distribution function is constructed so that the working state of each winding can be understood more accurately, and the potential distribution visualization of the three-phase rotor winding is helpful for rapid identification and location of faults. And according to the potential distribution diagram of the three-phase rotor winding, the faulty phase winding with a fault is determined from the three-phase rotor winding, and the visual identification of the faulty phase winding is realized. In addition, a fault location optimization model is constructed based on the potential distribution function and zero-sequence voltage of the faulty phase winding. Finally, based on the fault location optimization model, an iterative calculation is performed using a preset optimization algorithm until the preset iteration end condition is met. The fault position of the faulty phase winding is obtained, which can converge to the optimal solution quickly, shorten the fault analysis time, and quickly provide fault location information, thereby improving the accuracy of fault location.

[0085] In an exemplary embodiment, step S102 of acquiring the zero-sequence voltage of the variable speed pumped storage unit and the phase potential of each phase rotor winding includes:

[0086] The voltage measurement value of each phase rotor winding is obtained; the zero-sequence voltage of the variable speed pumped storage unit is determined according to the voltage measurement value of each phase rotor winding; the phase potential of each phase rotor winding is determined according to the voltage measurement value and zero-sequence voltage of each phase rotor winding.

[0087] Among them, the voltage measurement value usually refers to the voltage across a specific phase winding (for example, phase A, phase B, phase C). In a variable-speed pumped storage unit, these voltage measurement values ​​respectively reflect the electrical characteristics and status of each winding during operation.

[0088] The phase potential of each phase rotor winding refers to the potential value of the phase winding relative to a reference point (such as the ground). The potential represents the energy level of a charge in an electric field and is related to the voltage, but emphasizes the position of the electric energy at a certain point. In this embodiment, the reference point is the zero-sequence voltage.

[0089] Optionally, the system obtains the voltage measurement value of each phase rotor winding collected by the measuring device, and calculates the average value according to the voltage measurement value of each phase rotor winding as the zero-sequence voltage of the variable speed pumped storage unit. The corresponding formula is:

[0090]

[0091] in, is the zero sequence voltage, and They are the voltage measurement values ​​of the three-phase rotor windings respectively.

[0092] Furthermore, the system determines the difference between the voltage measurement value of each phase rotor winding and the zero-sequence voltage as the phase potential of each phase rotor winding.

[0093] In this embodiment, the voltage measurement value of each phase rotor winding is obtained, and the zero-sequence voltage and phase potential are calculated based on this information, which can not only provide comprehensive status information of the rotor winding of the variable-speed pumped storage unit, but also provide a data basis for subsequent fault location.

[0094] In an exemplary embodiment, a potential distribution function of each phase rotor winding is constructed according to the zero-sequence voltage and the phase potential of each phase rotor winding, including:

[0095] According to the phase potential of each phase rotor winding, the amplitude, phase and phase angle of the phase potential of each phase rotor winding are determined; according to the zero-sequence voltage, the phase potential of each phase rotor winding and the corresponding amplitude, phase and phase angle, the potential distribution function of each phase rotor winding is constructed.

[0096] Among them, the amplitude of the phase potential refers to the absolute value of the potential of a certain phase winding at a specific time or measurement point, usually expressed in volts (V), representing the magnitude of the potential without considering its direction. Among them, the phase of the phase potential refers to the angle of the potential related to time within a cycle, indicating the specific position or time delay of the phase potential on the time axis, and the phase is usually expressed in degrees (°) or radians (rad). Among them, the phase angle of the phase potential is used to describe the angular part in the complex representation of the AC voltage or current, reflecting the angular relationship between the voltage or current vector and the reference coordinate (usually the real axis). This angle can represent the characteristics of the phase potential changing over time.

[0097] Optionally, the system takes the absolute value of the phase potential of each phase rotor winding, obtains the amplitude of the phase potential of each phase rotor winding, and determines the specific position or time delay of each phase potential on the time axis according to the phase potential of each phase rotor winding, determines the phase of the phase potential of each phase rotor winding, and further converts the phase potential of each phase rotor winding into polar coordinate form to determine the phase belt angle of each phase rotor winding. In addition, the system constructs the potential distribution function of each phase rotor winding according to the zero-sequence voltage, the phase potential of each phase rotor winding and the corresponding amplitude, phase, and phase belt angle. The corresponding formula includes:

[0098]

[0099] in, Characterize the potential distribution function, Characterizes the phase potential of the i-th phase rotor winding, Characterizes the amplitude corresponding to the phase potential of the i-th phase rotor winding, θ iCharacterizes the phase corresponding to the phase potential of the i-th phase rotor winding, Characterize the phase belt angle, represents the zero-sequence voltage, and α represents the location of the fault.

[0100] In this embodiment, the potential state of each phase winding can be analyzed through the potential distribution function to identify the fault phase and the fault location. The potential distribution of the fault phase is usually significantly different from the normal state. The potential distribution function can be used to monitor the operating status of the variable speed pumped storage unit in real time and discover potential fault hazards in time. Through the analysis of the potential distribution, the operation control strategy of the unit can be optimized to improve the power generation efficiency and the operation safety of the equipment.

[0101] In an exemplary embodiment, Figure 2 As shown, step S104 constructs a potential distribution diagram of the three-phase rotor winding according to the zero-sequence voltage and the phase potential of each phase rotor winding, including the following steps S202 to S206, wherein:

[0102] Step S202, determining the zero-sequence voltage phasor and the phase potential phasor of the rotor winding of each phase according to the zero-sequence voltage and the phase potential of the rotor winding of each phase.

[0103] Among them, phasor is a concept commonly used in AC circuits and electrical engineering. It is used to represent the magnitude and phase relationship of AC current and voltage. Phasor is usually expressed in the form of complex numbers and can handle the properties of sinusoidal waveforms well.

[0104] Optionally, the system determines the zero potential in the plane, takes the zero potential as the starting point, and determines the zero-sequence voltage phasor and the phase potential phasor of each phase rotor winding according to the amplitude and direction of the zero-sequence voltage and the voltage measurement values ​​of each phase rotor winding.

[0105] Step S204: determining an auxiliary line that lags the zero-sequence voltage by 90 degrees according to the zero-sequence voltage phasor.

[0106] Optionally, the system determines an auxiliary line that lags the zero-sequence voltage by 90 degrees according to the phase of the zero-sequence voltage phasor.

[0107] Step S206, constructing a potential distribution diagram of the three-phase rotor winding according to the zero-sequence electric and voltage phasors, the phase potential phasors of each phase rotor winding and the auxiliary lines.

[0108] Optionally, the system draws zero-sequence electric and voltage phasors, phase potential phasors of each phase rotor winding and auxiliary lines at the same zero point in the same phasor plane to construct a potential distribution diagram of the three-phase rotor winding.

[0109] In this embodiment, by constructing a potential distribution diagram of the three-phase rotor winding, a basis is provided for subsequent visual identification of the faulty phase winding, thereby improving the efficiency of identifying the faulty phase winding.

[0110] In an exemplary embodiment, step S106 determines a faulty phase winding having a fault from the three-phase rotor winding according to the potential distribution diagram of the three-phase rotor winding, including:

[0111] According to the potential distribution diagram of the three-phase rotor winding, the rotor winding whose phase potential phasor is in a cross relationship with the auxiliary line is determined as the faulty phase winding with a fault.

[0112] Optionally, the system determines, based on the potential distribution diagram of the three-phase rotor winding, a phase potential phasor in which the positional relationship between the phase potential phasor and the auxiliary line is a cross relationship from the three-phase rotor winding, as the target phase potential phasor, and determines the rotor winding of the target phase potential phasor as the faulty phase winding with a fault.

[0113] In this embodiment, by identifying the intersection relationship between the potential phasor of the three-phase rotor winding and the auxiliary line, the faulty phase winding can be directly located, and the faulty phase winding of the three-phase rotor winding can be preliminarily located, providing a basis for further locating the fault position in the faulty phase winding.

[0114] In an exemplary embodiment, Figure 3 As shown, a method for accurately locating rotor grounding faults of variable-speed pumped storage units based on optimization solution is provided. Among them:

[0115] Step 1: Split the traditional coil unit group into two groups of "4 turns coil + 3 turns coil" for each branch of the variable speed pumped storage unit rotor winding to form two sets of combinations, which are alternately connected in series to obtain the rotor winding potential distribution function.

[0116] Exemplarily, the obtained A-phase rotor winding potential distribution function is:

[0117]

[0118] in, is the zero-sequence voltage, which is calculated from the three-phase voltage measurements. is the phase potential of phase A, given by and Get the difference. The amplitude and phase of and θ A . is the phase angle. α is the fault position.

[0119] Similarly, the obtained B-phase and C-phase rotor winding potential distribution functions are:

[0120]

[0121] Step 2: Draw the zero-sequence voltage phasor, the rotor three-phase voltage phasor, the potential distribution of each phase winding, and the auxiliary line that lags the zero-sequence voltage phasor by 90 degrees on the phasor plane. Determine the ground fault phase based on the intersection of the auxiliary line and the winding potential distribution.

[0122] The basis for judging the faulty phase is: the phase with which the auxiliary line intersects the winding potential is the faulty phase.

[0123] Step 3: Based on the fault phase selection, a fault location optimization model is established and solved using the Aurora optimization algorithm to achieve accurate fault location.

[0124] Exemplarily, the results of the modeling method verified by simulation experiments are as follows. A quasi-distributed parameter simulation model of the rotor winding is established in PSCAD / EMTDC software (a software tool widely used in power system modeling and simulation). Ground faults are set at different positions of the rotor winding, specifically: (1) f1, the fault phase is phase A, and the fault position α is 0.1429; (2) f2, the fault phase is phase C, and the fault position α is 0.2857; (3) f3, the fault phase is phase B, and the fault position α is 0.4286; (4) f4, the fault phase is phase A, and the fault position α is 0.5714; (5) f5, the fault phase is phase C, and the fault position α is 0.7143; (6) f6, the fault phase is phase B, and the fault position α is 0.8571.

[0125] In order to analyze the performance of the proposed phase selection method under different fault conditions, a variety of different fault transition resistances are set at f1~f3. Including: setting a metallic ground fault at f1, setting a 500 ohm ground fault at f2, and setting a resistance of The phasor diagrams of the three faults f1, f2 and f3 are as follows Figure 4 As shown in (a), (b) and (c) in the figure, in actual situations, the potential distribution diagram of the three-phase rotor winding is not limited to these three cases. It can be found that the auxiliary lines can intersect with the potential trajectory of the fault phase, and then accurately identify the ground fault phase, that is, the fault phase selection method is applicable under different fault locations and different ground fault resistance conditions.

[0126] To further verify the effectiveness of the proposed positioning method under different fault conditions, ground faults with transition resistances of 10Ω, 100Ω, 1000Ω and 10kΩ are set at f1~f6 respectively. Based on the above fault phase selection, the optimization model of fault positioning is listed and solved by the Aurora optimization algorithm. The positioning results are shown in Table 1. It can be found that the positioning error of the proposed method under different fault conditions does not exceed half a turn of the coil. When looking for the grounding fault point, the maintenance personnel can focus on checking the two turns of the coil near the positioning result, and they will definitely be able to find the actual fault point. The effectiveness of the proposed rotor grounding fault precise positioning method is verified. As shown in Table 1, the positioning results of the rotor winding grounding fault under different fault conditions are provided.

[0127] Table 1

[0128]

[0129]

[0130] In this embodiment, the traditional coil unit group is split into two groups of "4 turns coil + 3 turns coil" through each branch of the variable speed pumped storage unit rotor winding to form two sets of combinations, which are alternately connected in series, thereby obtaining the rotor winding potential distribution function; and on the phasor plane, the zero-sequence voltage phasor, the rotor three-phase voltage phasor, the potential distribution of each phase winding, and the auxiliary line that lags the zero-sequence voltage phasor by 90 degrees are drawn. According to the intersection of the auxiliary line and the winding potential distribution, the ground fault phase is judged; based on the fault phase selection, a fault location optimization model is established, and the Aurora optimization algorithm is used to solve it to achieve accurate fault location. At the same time, the effectiveness and accuracy of the proposed method are verified by taking a simulation example as an example.

[0131] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0132] Based on the same inventive concept, the embodiment of the present application also provides a variable speed pumped storage unit rotor grounding fault locating device for implementing the variable speed pumped storage unit rotor grounding fault locating method involved above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above method, so the specific limitations in one or more embodiments of the variable speed pumped storage unit rotor grounding fault locating device provided below can refer to the above limitations on the variable speed pumped storage unit rotor grounding fault locating method, and will not be repeated here.

[0133] In an exemplary embodiment, Figure 5 As shown, a variable speed pumped storage unit rotor grounding fault location device 500 is provided, comprising: an electrical parameter acquisition module 502, a potential distribution determination module 504, a fault phase determination module 506, a model construction module 508 and a fault location module 510, wherein:

[0134] The electrical parameter acquisition module 502 is used to acquire the zero-sequence voltage of the variable speed pumped storage unit and the phase potential of each phase rotor winding; the variable speed pumped storage unit includes a three-phase rotor winding;

[0135] The potential distribution determination module 504 is used to construct a potential distribution function of each phase of the rotor winding and a potential distribution diagram of the three-phase rotor winding according to the zero-sequence voltage and the phase potential of each phase of the rotor winding.

[0136] The fault phase determination module 506 is used to determine the faulty phase winding having a fault from the three-phase rotor winding according to the potential distribution diagram of the three-phase rotor winding.

[0137] A model building module 508 is used to build a fault location optimization model according to the potential distribution function and zero-sequence voltage of the fault phase winding;

[0138] The fault location module 510 is used to perform iterative calculations according to the fault location optimization model using a preset optimization algorithm until a preset iteration end condition is met, thereby obtaining the fault location of the faulty phase winding.

[0139] Furthermore, in one embodiment, the electrical parameter acquisition module 502 is also used to obtain the voltage measurement value of each phase rotor winding; determine the zero-sequence voltage of the variable-speed pumped storage unit based on the voltage measurement value of each phase rotor winding; determine the phase potential of each phase rotor winding based on the voltage measurement value and zero-sequence voltage of each phase rotor winding.

[0140] Furthermore, in one embodiment, the potential distribution determination module 504 is also used to determine the amplitude, phase and phase belt angle of the phase potential of each phase rotor winding according to the phase potential of each phase rotor winding; and construct the potential distribution function of each phase rotor winding according to the zero-sequence voltage, the phase potential of each phase rotor winding and the corresponding amplitude, phase, and phase belt angle.

[0141] Furthermore, in one embodiment, the potential distribution determination module 504 is also used to determine the zero-sequence voltage phasor and the phase potential phasor of each phase of the rotor winding based on the zero-sequence voltage and the phase potential of each phase of the rotor winding; determine the auxiliary line that lags the zero-sequence voltage by 90 degrees based on the zero-sequence voltage phasor; and construct the potential distribution diagram of the three-phase rotor winding based on the zero-sequence voltage phasor, the phase potential phasor of each phase of the rotor winding and the auxiliary line.

[0142] Furthermore, in one embodiment, the fault phase determination module 506 is also used to determine, from the three-phase rotor winding, a rotor winding whose phase potential phasor is in a cross relationship with the auxiliary line as a faulty phase winding with a fault, based on the potential distribution diagram of the three-phase rotor winding.

[0143] Each module in the variable speed pumped storage unit rotor grounding fault location device 500 can be implemented in whole or in part by software, hardware, or a combination thereof. Each module can be embedded in or independent of a processor in a computer device in the form of hardware, or can be stored in a memory in a computer device in the form of software, so that the processor can call and execute operations corresponding to each module.

[0144] In an exemplary embodiment, a computer device is provided. The computer device may be a server, and its internal structure diagram may be as shown in FIG. Figure 6 As shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, referred to as I / O) and a communication interface. The processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store data such as zero-sequence voltage and the phase potential of each phase rotor winding. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a method for locating a rotor grounding fault of a variable-speed pumped storage unit is implemented.

[0145] Those skilled in the art will understand that Figure 6 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0146] In one embodiment, a computer device is further provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above method embodiments when executing the computer program.

[0147] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments are implemented.

[0148] In one embodiment, a computer program product is provided, including a computer program, which implements the steps in the above method embodiments when executed by a processor.

[0149] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, an artificial intelligence (AI) processor, etc., but are not limited to this.

[0150] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0151] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A method for locating rotor grounding fault of a variable speed pumped storage unit, characterized in that: The method comprises: Obtaining the zero-sequence voltage of the variable-speed pumped storage unit and the phase potential of each phase rotor winding; the variable-speed pumped storage unit includes the three-phase rotor winding; Constructing a potential distribution function of the rotor winding of each phase and a potential distribution diagram of the rotor winding of three phases according to the zero-sequence voltage and the phase potential of the rotor winding of each phase; According to the potential distribution diagram of the three-phase rotor winding, a faulty phase winding having a fault is determined from the three-phase rotor winding; Constructing a fault location optimization model according to the potential distribution function of the fault phase winding and the zero-sequence voltage; According to the fault location optimization model, a preset optimization algorithm is used to perform iterative calculations until a preset iteration end condition is met, thereby obtaining the fault position of the faulty phase winding.

2. The method according to claim 1, characterized in that The step of obtaining the zero-sequence voltage of the variable speed pumped storage unit and the phase potential of each phase of the rotor winding comprises: Obtaining voltage measurement values ​​of the rotor windings of each phase; Determining the zero-sequence voltage of the variable speed pumped storage unit according to the voltage measurement value of the rotor winding of each phase; The phase potential of the rotor winding of each phase is determined according to the voltage measurement value of the rotor winding of each phase and the zero-sequence voltage.

3. The method according to claim 1, characterized in that The step of constructing a potential distribution function of the rotor winding of each phase according to the zero-sequence voltage and the phase potential of the rotor winding of each phase comprises: Determining the amplitude, phase and phase angle of the phase potential of the rotor winding of each phase according to the phase potential of the rotor winding of each phase; A potential distribution function of the rotor winding of each phase is constructed according to the zero-sequence voltage, the phase potential of the rotor winding of each phase and the corresponding amplitude, phase, and phase belt angle.

4. The method according to claim 3, characterized in that According to the zero-sequence voltage, the phase potential of the rotor winding of each phase and the corresponding amplitude, phase, and phase belt angle, the potential distribution function of the rotor winding of each phase is constructed, and the corresponding formula includes: in, Characterize the potential distribution function, Characterizes the phase potential of the rotor winding of the i-th phase, Characterizes the amplitude corresponding to the phase potential of the rotor winding of the i-th phase, θ i Characterizing the phase corresponding to the phase potential of the rotor winding of the i-th phase, Characterize the phase band angle, represents the zero-sequence voltage, and α represents the location where the fault occurs.

5. The method according to claim 1, characterized in that The step of constructing a potential distribution diagram of the three-phase rotor winding according to the zero-sequence voltage and the phase potential of each phase of the rotor winding comprises: Determine the zero-sequence voltage phasor and the phase potential phasor of the rotor winding of each phase according to the zero-sequence voltage and the phase potential of the rotor winding of each phase; According to the zero-sequence voltage phasor, an auxiliary line lagging the zero-sequence voltage by 90 degrees is determined; A potential distribution diagram of the three-phase rotor winding is constructed according to the zero-sequence voltage phasor, the phase potential phasor of each phase of the rotor winding and the auxiliary line.

6. The method according to claim 5, characterized in that The method of determining a faulty phase winding having a fault from the three-phase rotor winding according to the potential distribution diagram of the three-phase rotor winding comprises: According to the potential distribution diagram of the three-phase rotor winding, the rotor winding whose phase potential phasor is in a cross relationship with the auxiliary line is determined as the faulty phase winding.

7. The method according to claim 1, characterized in that According to the potential distribution function of the fault phase winding and the zero-sequence voltage, a fault location optimization model is constructed, and the corresponding formula includes: Among them, α represents the fault location, f(α) represents the objective function, Characterize the zero-sequence voltage, A potential distribution function characterizing the faulty phase winding.

8. A variable speed pumped storage unit rotor grounding fault location device, characterized in that: The device comprises: An electrical parameter acquisition module, used to acquire the zero-sequence voltage of a variable-speed pumped storage unit and the phase potential of each phase rotor winding; the variable-speed pumped storage unit includes three-phase rotor windings; A potential distribution determination module, configured to construct a potential distribution function of the rotor winding of each phase and a potential distribution diagram of the rotor winding of three phases according to the zero-sequence voltage and the phase potential of the rotor winding of each phase; A fault phase determination module, used to determine a faulty phase winding having a fault from the three-phase rotor windings according to a potential distribution diagram of the three-phase rotor windings; A model building module, used to build a fault location optimization model according to the potential distribution function of the fault phase winding and the zero-sequence voltage; The fault location module is used to perform iterative calculations according to the fault location optimization model using a preset optimization algorithm until a preset iteration end condition is met, thereby obtaining the fault position of the fault phase winding.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

Images