CN-122017675-A - Fault positioning method and device for floating photovoltaic power station grounding resistor

CN122017675ACN 122017675 ACN122017675 ACN 122017675ACN-122017675-A

Abstract

The application provides a fault positioning method and device for a grounding resistor of a floating photovoltaic power station, wherein the method is applied to a controller in a fault positioning system, the fault positioning system also comprises a grounding grid of the floating photovoltaic power station, a sensor network formed by deploying sensors at key nodes of the grounding grid and a signal generator, and the method comprises the steps of responding to a received fault positioning instruction, triggering the signal generator to inject a high-frequency test current signal into the grounding grid; the method comprises the steps of acquiring voltage response signals of key nodes through a sensing network, acquiring a current-voltage data set, carrying out resistivity distribution reconstruction by adopting an impedance imaging algorithm based on the current-voltage data set to generate a three-dimensional resistivity distribution map of a grounding network, and positioning an abnormal region with the resistivity exceeding a preset threshold value in the grounding network according to the three-dimensional resistivity distribution map. The method realizes three-dimensional visual imaging of resistivity distribution in the grounding grid and accurate positioning of abnormal areas.

Inventors

LI HONGLIANG
WEN DONGBIN
FENG WEIKANG
FAN WENBO
ZHAN GUILONG
LIN YAOZU
Shi Qiayin
LIU RUICHAO
Zhou Dieming
WANG YUFEI

Assignees

华能(福建漳州)能源有限责任公司
中国华能集团清洁能源技术研究院有限公司

Dates

Publication Date: 20260512
Application Date: 20260325

Claims (10)

1. The fault positioning method of the grounding resistance of the floating photovoltaic power station is characterized by being applied to a controller in a fault positioning system, wherein the fault positioning system further comprises a grounding grid of the floating photovoltaic power station, a sensor network formed by deploying sensors at key nodes of the grounding grid and a signal generator, and the method comprises the following steps: responding to the received fault positioning instruction, triggering a signal generator to inject a high-frequency test current signal into a grounding grid; Acquiring a current-voltage data set through voltage response signals of each key node acquired by the sensing network; based on the current-voltage data set, adopting an impedance imaging algorithm to reconstruct resistivity distribution, and generating a three-dimensional resistivity distribution map of the grounding grid; and positioning an abnormal region with the resistance value exceeding a preset threshold value in the grounding grid according to the three-dimensional resistivity distribution diagram.
2. The method of claim 1, wherein triggering the signal generator to inject the high frequency test current signal into the ground network in response to the received fault location instruction comprises: Controlling the signal generator to inject a high-frequency test current signal with the frequency within a preset frequency range into one or more injection points of the grounding grid; the injection point is a designated location on the ground network for accessing test current that coincides with part or all of the critical nodes for deploying sensors are independently disposed.
3. The method of claim 2, wherein injecting the high frequency test current signal having a frequency within a predetermined frequency range into the one or more injection points of the ground grid comprises: controlling the signal generator to sequentially inject high-frequency test current signals with the frequency within a preset frequency range into a single injection point of the grounding grid according to a preset polling sequence; Or controlling the signal generator to synchronously inject multiple high-frequency test current signals into multiple injection points of the grounding grid according to preset time sequences and phases.
4. The method of claim 1, wherein the critical nodes comprise at least electrical connection points between adjacent array elements in a floating photovoltaic array, a pre-set ground connection point for a metal floating body platform supporting a photovoltaic module, and connection points for connecting the metal floating body platform to an underwater ground conductor.
5. The method of claim 1, wherein, in response to the received fault location instruction, before triggering the signal generator to inject the high frequency test current signal into the ground network, the method further comprises: acquiring current environmental parameters, wherein the environmental parameters at least comprise the resistivity, the water temperature and the water level of a water body where a floating photovoltaic power station is positioned; And dynamically adjusting the frequency and/or amplitude of the high-frequency test current signal according to the current environment parameter.
6. The method of claim 1, wherein, in response to the received fault location instruction, before triggering the signal generator to inject the high frequency test current signal into the ground network, the method further comprises: performing electromagnetic field simulation on the three-dimensional structure model of the grounding grid; And determining the optimal deployment position and density of the sensor in the sensor network and the optimal position of the injection point of the high-frequency test current signal according to the simulation result.
7. The method of claim 1, wherein generating a three-dimensional resistivity profile of the ground grid based on the current-voltage dataset using an impedance imaging algorithm for resistivity profile reconstruction comprises: Based on the structural information and the spatial information of the grounding grid, constructing a three-dimensional discretization model of a calculation domain of the grounding grid, wherein the model is composed of a plurality of units, and endowing each unit with conductivity parameters representing the conductivity characteristics of the unit; Combining the current-voltage data set with the three-dimensional discretization model, constructing and solving an inverse problem which takes the conductivity of each unit as an optimization variable and takes the matching of the predicted voltage and the measured voltage as a target, and obtaining the optimal conductivity distribution of all units through iterative optimization; And calculating and generating a three-dimensional resistivity distribution map representing the spatial distribution of the resistance characteristics of the grounding grid system according to the optimal conductivity distribution.
8. The utility model provides a fault location device of showy photovoltaic power plant earth resistance which characterized in that is applied to the controller in the fault location system, and the fault location system still includes showy photovoltaic power plant's earth mat, disposes sensor network and the signal generator that the sensor formed at each key node of this earth mat, and the device includes: the trigger unit is used for responding to the received fault positioning instruction, and triggering the signal generator to inject a high-frequency test current signal into the grounding grid; The acquisition unit is used for acquiring a current-voltage data set through voltage response signals of each key node acquired by the sensing network; the generation unit is used for carrying out resistivity distribution reconstruction by adopting an impedance imaging algorithm based on the current-voltage data set to generate a three-dimensional resistivity distribution map of the grounding grid; and the positioning unit is used for positioning an abnormal region with the resistance value exceeding a preset threshold value in the grounding grid according to the three-dimensional resistivity distribution diagram.
9. An electronic device, characterized in that the electronic device comprises a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory are in communication with each other through the communication bus; a memory for storing a computer program; a processor for implementing the method of any of claims 1-7 when executing a program stored on a memory.
10. A computer readable storage medium, characterized in that the computer readable storage medium has stored therein a computer program which, when executed by a processor, implements the method of any of claims 1-7.

Description

Fault positioning method and device for floating photovoltaic power station grounding resistor Technical Field The application relates to the technical field of fault diagnosis of floating photovoltaic power stations, in particular to a fault positioning method and device for a grounding resistor of a floating photovoltaic power station. Background In recent years, with the rapid development of photovoltaic power generation technology, a floating photovoltaic power station gradually becomes one of important forms of photovoltaic power generation due to the advantages of saving land resources, reducing evaporation of water and the like. The grounding system is used as a key component for guaranteeing the electrical safety of the power station, and the performance of the grounding system directly influences the operation safety of the power station and the protection of personnel and equipment. At present, a common grounding system is generally formed by connecting a metal grounding electrode buried underground with a conductor to form a net structure, and the grounding system is divided into a photovoltaic array grounding part and an electrical equipment grounding part, and the total grounding resistance is required to be not more than 4 ohms so as to meet the safety specification. In the prior art, the ground resistance is monitored by adopting a periodic field measurement or a local point measurement mode, for example, a ground resistance tester is used for measuring at a ground lead. Part of the system can be deployed with a fixed sensor for continuous monitoring, but is generally limited to the acquisition of the total resistance value, and cannot realize the fine detection of the internal resistance distribution of the grounding network. For a floating photovoltaic power station, the grounding system is in a water surface environment and is more obviously influenced by factors such as water body fluctuation and corrosion, and the grounding network state is difficult to be comprehensively reflected in real time by the traditional method. Based on the existing grounding resistance monitoring technology, the method has the main problems that the internal resistance distribution condition of the grounding grid cannot be obtained intuitively in real time, the high-resistance abnormal region is difficult to accurately locate, and particularly in a complex water body environment such as a floating photovoltaic power station, the traditional point measurement or overall monitoring method is slow in response and low in spatial resolution, so that local faults of the grounding grid are difficult to discover and process in time, and the running risk of the power station is increased. Disclosure of Invention The embodiment of the application aims to provide a fault positioning method and device for a floating photovoltaic power station grounding resistor, which are used for realizing three-dimensional visual imaging of internal resistivity distribution of a grounding grid and accurate positioning of an abnormal region. In a first aspect, a fault location method for a ground resistor of a floating photovoltaic power station is provided, and the fault location method is applied to a controller in a fault location system, where the fault location system further includes a ground network of the floating photovoltaic power station, a sensor network formed by deploying sensors at key nodes of the ground network, and a signal generator, and the method may include: responding to the received fault positioning instruction, triggering a signal generator to inject a high-frequency test current signal into a grounding grid; Acquiring a current-voltage data set through voltage response signals of each key node acquired by the sensing network; based on the current-voltage data set, adopting an impedance imaging algorithm to reconstruct resistivity distribution, and generating a three-dimensional resistivity distribution map of the grounding grid; and positioning an abnormal region with the resistance value exceeding a preset threshold value in the grounding grid according to the three-dimensional resistivity distribution diagram. In one possible implementation, in response to a received fault location instruction, the trigger signal generator injects a high frequency test current signal into the ground network, comprising: Controlling the signal generator to inject a high-frequency test current signal with the frequency within a preset frequency range into one or more injection points of the grounding grid; The injection point is a designated location on the ground network for accessing test current that is partially coincident with or is disposed entirely independently of the critical node for deploying the sensor. In one possible implementation, the method for injecting the high-frequency test current signal with the frequency within the preset frequency range into the one or more injection points of the grounding grid include