Photovoltaic array fault location method, system, electronic device and storage medium

Abstract

This invention provides a photovoltaic array fault location method, system, electronic device, and storage medium. The number of voltage sensors and bidirectional switches is determined based on the size of the photovoltaic array, and the voltage sensors are arranged according to a preset arrangement rule; based on the reference power P... r、 Power P act The photovoltaic array is identified as having a fault, and the fault type is diagnosed. Fault sequences are located using a voltage difference matrix. Based on the fault sequence and the fault location rules corresponding to the fault type, the component fault is determined, and the location of the faulty component is output. Building upon an improved voltage sensor placement method, and by maximizing the use of voltage sensors for large-scale photovoltaic arrays, fault component location rules for open-circuit faults, short-circuit faults, abnormal aging faults, and partial shading faults are further developed, enabling precise location of faulty components.

Description

Technical Field

[0001] This invention relates to the field of fault location technology, and more specifically, to a method, system, electronic device, and storage medium for locating faults in photovoltaic arrays. Background Technology

[0002] In recent years, with the gradual increase in photovoltaic (PV) installed capacity, the reliability and stability of PV system operation have received increasing attention. However, because PV systems are installed in harsh outdoor environments, they are prone to PV array failures, affecting the efficiency and safety of the PV system, and even causing fires.

[0003] The main faults of photovoltaic arrays include open circuit faults, short circuit faults, abnormal aging faults, and partial shading faults. Therefore, in order to accurately and promptly troubleshoot these faults, it is necessary to design a photovoltaic array positioning method that is more accurate, less complex, and less costly, thereby maximizing the use of voltage sensors and reducing equipment investment. Summary of the Invention

[0004] In view of this, the purpose of this embodiment of the invention is to provide a cluster where each node can be used efficiently, and cluster nodes can be added or removed in real time as needed, so as to solve the performance bottleneck and resource idleness of a single service node and achieve high performance and high availability.

[0005] A first aspect of the present invention provides a method for locating faults in a photovoltaic array, the method comprising:

[0006] S1, obtain the number of series and parallel connections of the photovoltaic array, as well as the photovoltaic array parameters, including the size of the photovoltaic array; determine the number of voltage sensors and bidirectional switches based on the size of the photovoltaic array, and arrange the voltage sensors according to the preset voltage sensor arrangement rules;

[0007] S2, collect the current and voltage of the photovoltaic array under MPP, and calculate the power P. act ; Obtain the reference power P under MPP r According to the reference power P r、 Power P act The photovoltaic array is determined to be faulty, and the fault type is determined based on the fault diagnosis.

[0008] S3. Calculate the voltage difference matrix based on the voltage value measured by the voltage sensor, locate the fault series based on the voltage difference matrix, determine the component fault based on the fault series and the fault location rules corresponding to the fault type, and output the location of the faulty component.

[0009] Furthermore, the voltage sensor arrangement is performed according to a preset voltage sensor arrangement rule, including:

[0010] Every three adjacent strings form a subarray, and one string is selected as the reference string; the connection between adjacent components in each string in the photovoltaic array is called a node; the node of the reference string is cross-connected to the nodes of the other two strings through bidirectional switches; voltage sensors connect all nodes.

[0011] Furthermore, according to the reference power P r、 Power P act The photovoltaic array is determined to have a fault, and the fault type is determined based on fault diagnosis, including:

[0012] According to the reference power P r Determine the power deviation P ε =10%P r ;

[0013] If |P act -P r |>P ε If the condition persists for a predetermined time threshold, it is determined that there is a potential fault in the photovoltaic array. Fault diagnosis is then used to distinguish the type of fault.

[0014] Furthermore, the fault series is located based on the voltage difference matrix. Based on the fault series and the fault location rules corresponding to the fault type, the component fault is determined, and the location of the faulty component is output. This includes determining that, under normal conditions, the output voltage of each PV component at the MPP is V. m ;

[0015] Total output voltage of PV array (mV) m Therefore, the voltage of the x-th row of the y-th string... Vxy The calculation is as follows:

[0016]

[0017] In V xy Let be the component voltage in the x-th row of the y-th string;

[0018] Based on the characteristics of open-circuit faults, the output voltage of the component experiencing an open-circuit fault is equal to V. oc If an open-circuit fault occurs in the y-th string, then the voltage V xy Defined as:

[0019]

[0020] Based on the characteristics of short-circuit faults, the voltage of the component experiencing a short-circuit fault is 0, while the voltage of other normal components is V. m When a short-circuit fault occurs in the y-th string of the photovoltaic array, the voltage from the top of module (x, y) to the bottom of module (1, y) is represented by V. xy It is represented and defined as:

[0021]

[0022] When an abnormal aging failure occurs, the voltage of the faulty component is less than V. m However, it is greater than 0; if an abnormal aging fault occurs in the y-th string, the voltage V xy Given:

[0023]

[0024] In the event of a partial shading failure, the voltage of the shaded component is between 0 and V. oc Between; when a partial shading fault occurs in the y-th string, the voltage V xy It can be represented as:

[0025]

[0026] The voltage V of components (a, b) ab Similar to V xy Then the voltage sensor connects component (x, y) and component (a, b), using V ab，xy The calculation is as follows:

[0027] V ab,xy =V ab -V xy

[0028] For the subarray, due to the voltage sensor multiplexing method, only (m-1) voltage sensors and bidirectional switches are needed; the input voltage values ​​collected by the voltage sensors are recorded as voltage vector V. t After time t+1, switch the switch to the other side, collect another series of voltage values, and record them as V. t+1 :

[0029]

[0030] Where i is the number of voltage sensors, i∈[1,m-1];

[0031] The voltage matrix V is defined as follows:

[0032] V = [V t V t+1 ]

[0033] As stated above, the output voltage of the photovoltaic module is V. m The subarray is in a fault-free state; therefore, the reference voltage V of the subarray is... nor It can be represented as:

[0034]

[0035] Where i = 1, 2, ..., m-1;

[0036] To locate the faulty component in a fault chain, the voltage difference matrix ΔV can be defined as:

[0037]

[0038] The voltage difference matrix ΔV under normal conditions can be calculated as follows:

[0039]

[0040] Fault string judgment matrix V j Defined as:

[0041] V j =ΔV - ΔV nor =[ΔV j_t ,ΔV j_t+1 ]

[0042]

[0043] Furthermore, the fault types include: short-circuit fault, partial shading fault, abnormal aging fault, and open-circuit fault; based on the fault sequence and the fault location rules corresponding to the fault types, component faults are determined, including:

[0044] Obtain the pre-defined mapping relationship between photovoltaic modules and corresponding voltage difference rules under different fault types;

[0045] Set the error coefficient ΔV ε ΔV ε =5%ΔV;

[0046] According to the voltage difference matrix ΔV j，act and the voltage difference ΔV under the fault type corresponding to the mapping relationship. j If |ΔV j,act -ΔV j |<ΔV ε If the corresponding component is faulty, the location of the faulty component will be output.

[0047] Furthermore, a second aspect of the present invention provides a photovoltaic array fault location system, the system comprising:

[0048] The module is configured to acquire the number of series and parallel connections of the photovoltaic array, as well as the photovoltaic array parameters, including the size of the photovoltaic array. Based on the size of the photovoltaic array, the number of voltage sensors and bidirectional switches is determined, and the voltage sensor arrangement is performed according to a preset voltage sensor arrangement rule.

[0049] The data acquisition and diagnostic module acquires the current and voltage of the photovoltaic array under MPP conditions and calculates the power P. act ; Obtain the reference power P under MPP r According to the reference power Pr、 Power P act The photovoltaic array is determined to be faulty, and the fault type is determined based on the fault diagnosis.

[0050] The fault location module calculates a voltage difference matrix based on the voltage values ​​measured by the voltage sensor, locates the fault series based on the voltage difference matrix, determines the component fault based on the fault series and the fault location rules corresponding to the fault type, and outputs the location of the faulty component.

[0051] Furthermore, a third aspect of the present invention provides an electronic device comprising: one or more processors, and a memory for storing one or more computer programs; the computer programs being configured to be executed by the one or more processors, the programs including steps for performing the photovoltaic array fault location method as described above.

[0052] Furthermore, a fourth aspect of the present invention provides a storage medium storing a computer program; the program is loaded and executed by a processor to implement the steps of the photovoltaic array fault location method as described above.

[0053] In this invention, the number of strings, the number of parallel connections, and the parameters of the photovoltaic array are obtained, including the size of the photovoltaic array. The number of voltage sensors and bidirectional switches is determined based on the size of the photovoltaic array, and the voltage sensors are arranged according to a preset arrangement rule. The current and voltage of the photovoltaic array under MPP (Multi-Phase Power) are collected, and the power P is calculated. act ; Obtain the reference power P under MPP r According to the reference power P r、 Power P act The photovoltaic array is identified as faulty, and the fault type is determined based on fault diagnosis. A voltage difference matrix is ​​calculated based on the voltage values ​​measured by voltage sensors. Fault sequences are located using this matrix. Based on the fault sequences and the fault location rules corresponding to the fault types, the component fault is determined, and the location of the faulty component is output. Based on an improved voltage sensor arrangement method, this approach maximizes the use of voltage sensors for large-scale photovoltaic arrays, offering advantages in terms of sensor quantity and wiring complexity. Furthermore, fault component location rules are established for open-circuit faults, short-circuit faults, abnormal aging faults, and partial shading faults, enabling precise location of faulty components. Attached Figure Description

[0054] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0055] Figure 1 This is a schematic diagram of a photovoltaic grid-connected system model disclosed in an embodiment of the present invention;

[0056] Figure 2 This is a schematic flowchart of the photovoltaic array fault location method disclosed in the embodiments of the present invention;

[0057] Figures 3(a)-(c) are topological diagrams of voltage sensors and bidirectional switches for different photovoltaic arrays disclosed in the embodiments of the present invention;

[0058] Figure 4 This is the hardware-in-the-loop simulation platform disclosed in the embodiments of the present invention;

[0059] Figure 5 This is a schematic diagram of the topology of the photovoltaic array fault simulation model disclosed in the embodiments of the present invention;

[0060] Figure 6 This is a schematic diagram of the photovoltaic array fault location system disclosed in an embodiment of the present invention. Detailed Implementation

[0061] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided to make this application more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art.

[0062] Furthermore, the described features, structures, or characteristics are combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a thorough understanding of embodiments of this application. However, those skilled in the art will recognize that the technical solutions of this application can be practiced without one or more of these specific details, or with other methods, components, apparatuses, steps, etc. In other instances, well-known methods, apparatuses, implementations, or operations are not shown or described in detail to avoid obscuring various aspects of this application.

[0063] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities may be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices.

[0064] The flowcharts shown in the accompanying drawings are merely illustrative and do not necessarily include all content and operations / steps, nor do they necessarily need to be performed in the described order. For example, some operations / steps may be broken down, while others may be combined or partially combined; therefore, the actual execution order may change depending on the specific circumstances.

[0065] It should be noted that "multiple" in this embodiment refers to two or more.

[0066] The implementation details of the technical solutions in the embodiments of this application are described in detail below:

[0067] Generally, photovoltaic modules can be connected in series and / or parallel to form a photovoltaic array. Therefore, there are currently five topologies: series (S), parallel (P), series-parallel (SP), mesh structure (TCT), and complex-total-cross-tied array (CTCT). However, SP is widely used to obtain higher voltage and current.

[0068] Photovoltaic grid-connected system model as follows Figure 1 As shown, this photovoltaic system consists of a photovoltaic array, a DC / DC converter controlled by maximum power point tracking (MPPT), and a DC / AC converter connected to the power grid. In this system, the photovoltaic array is composed of three parallel branches, with four modules connected in series in each branch. Typical fault types occurring in the photovoltaic array are marked, such as open-circuit faults, short-circuit faults, degradation faults, and partial shading faults.

[0069] Studying the output characteristics of photovoltaic arrays under different fault conditions, for the output current and power of photovoltaic arrays at the maximum power point (MPP), it can be found that the current for open-circuit faults is much lower than that for fault-free faults. This is because the current of the open-circuit string is equal to zero, while the current for short-circuit faults, partial shading faults, and abnormal aging faults is close to that of the fault-free faults. For open-circuit faults, since the faulty module is open-circuited, the voltage of the module in the faulty string is equal to its open-circuit voltage (V). oc However, in other strings, the voltage equals the healthy voltage at the MPP. For short-circuit faults, the output voltage of the faulty component is equal to 0, therefore the output voltage of the photovoltaic array is less than the normal voltage. For partial shading faults, due to external environmental factors, the irradiance received by the photovoltaic array is uneven, which greatly affects the efficiency of the photovoltaic array. If the irradiance received by the photovoltaic module is close to 0, the fault is equivalent to an open-circuit fault. Therefore, the voltage of the partially shading component is between 0 and V. ocBetween 0 and V. To keep the voltage of the faulty component between 0 and V. oc In this embodiment, the received irradiance of the shadow component is greater than zero but less than 1000 W / m². 2 Abnormal aging faults are equivalent to increasing the series resistance of the faulty component or decreasing the parallel resistance. Since the voltage of the aged component is lower than the healthy voltage at the MPP, the voltage of the photovoltaic array is lower than the fault-free state. In this embodiment, an abnormal aging fault is simulated by connecting a 5Ω resistor in series with the component.

[0070] Please see Figure 2 , Figure 2 This is a flowchart illustrating a photovoltaic array fault location method disclosed in an embodiment of the present invention. Figure 2 As shown in the figure, a photovoltaic array fault location method according to an embodiment of the present invention includes:

[0071] S1, obtain the number of series and parallel connections of the photovoltaic array, as well as the photovoltaic array parameters, including the size of the photovoltaic array; determine the number of voltage sensors and bidirectional switches based on the size of the photovoltaic array, and arrange the voltage sensors according to the preset voltage sensor arrangement rules;

[0072] Furthermore, the voltage sensor arrangement is performed according to the preset voltage sensor arrangement rules, including: every three adjacent strings are arranged as a sub-array, and one string is selected as a reference string; the connection between adjacent components in each string of the photovoltaic array is called a node; the node of the reference string is cross-connected to the nodes of the other two strings respectively through bidirectional switches; the voltage sensor is connected to all nodes.

[0073] Specifically, in this embodiment, the number of strings and parallel connections of the photovoltaic array, as well as the photovoltaic array parameters provided by the manufacturer, are first input. Secondly, the number of voltage sensors and bidirectional switches is determined based on the size of the photovoltaic array. Figures 3(a)-(c) show the topology diagrams of voltage sensor and bidirectional switch arrangements for different photovoltaic arrays in this embodiment. Then, the voltage sensors and bidirectional switches are arranged according to Figure 3(a). This method differs slightly depending on the size of the photovoltaic array. For an m×n photovoltaic array, n can be divided into multiples of 3, with the remainder written as r. When r is 0, the PV array can be divided into n / 3 m×3 subarrays connected in parallel. For subarray 1, string 1 is used as the reference string, and the voltages of the other two strings are measured separately using voltage sensors via bidirectional switches. Sensor V 1,i A bidirectional switch, i = 1, 2, ..., m-2, m-1, is placed between strings 1 and 3 to connect strings 2 and 3. Therefore, this photovoltaic array requires (m × n) / 3 voltage sensors and (m × n) / 3 bidirectional switches.

[0074] When r = 1, it can be divided into (n+2) / 3 blocks, each block consisting of m×3 subarrays connected in parallel. As can be seen from Figure 3(b), in this case, the voltage sensor arrangement, subarray 2 consists of series 3 and series 4, therefore the sensor V... 2,i It is placed between strings 3 and 4. The other subarrays are similar to the previous ones; each subarray requires (m-1) voltage sensors and (m-1) bidirectional switches. Therefore, the photovoltaic array requires ((n-1)×m+3) / 3 voltage sensors. When r=2, it can be divided into (n+1) / 3 blocks, which are formed by connecting m×3 subarrays in parallel. As can be seen from Figure 3(c), in subarray 2, sensor V... 2,i The voltage sensor is placed between strings 4 and 5, and strings 5 ​​and 6 are connected by a bidirectional switch. Each subarray requires (m-1) voltage sensors and (m-1) bidirectional switches. Therefore, the photovoltaic array also requires n(m-1)×(n+2) / 3 voltage sensors.

[0075] S2, collect the current and voltage of the photovoltaic array under MPP, and calculate the power P. act ; Obtain the reference power P under MPP r According to the reference power P r、 Power P act The photovoltaic array is determined to be faulty, and the fault type is determined based on the fault diagnosis.

[0076] Furthermore, according to the reference power P r、 Power P act The photovoltaic array is determined to have a fault, and the fault type is determined based on fault diagnosis, including:

[0077] According to the reference power P r Determine the power deviation P ε =10%P r ;

[0078] If |P act -P r |>P ε If the condition persists for a predetermined time threshold, it is determined that there is a potential fault in the photovoltaic array. Fault diagnosis is then used to distinguish the type of fault.

[0079] S3. Calculate the voltage difference matrix based on the voltage value measured by the voltage sensor, locate the fault series based on the voltage difference matrix, determine the component fault based on the fault series and the fault location rules corresponding to the fault type, and output the location of the faulty component.

[0080] Specifically, in this embodiment, by acquiring voltage sensor values ​​under short-circuit, partial shading, abnormal aging, and open-circuit fault conditions, the corresponding faulty component can be located. To achieve accurate location of the faulty component, it is assumed that each photovoltaic module experiences only one type of fault within any given time period. Then, we introduce a position coordinate (x, y) corresponding to the x-th row of the y-th string of the PV array.

[0081] Furthermore, the fault sequence is located based on the voltage difference matrix. Based on the fault sequence and the fault location rules corresponding to the fault type, the component fault is determined, and the location of the faulty component is output, including:

[0082] Total output voltage of PV array (mV) m Therefore, the voltage of the x-th row of the y-th string... Vxy The following can be calculated:

[0083]

[0084] In V xy Let be the component voltage in the x-th row of the y-th string.

[0085] Based on the characteristics of open-circuit faults, the output voltage of the component experiencing an open-circuit fault is equal to V. oc If an open-circuit fault occurs in the y-th string, then the voltage V xy It can be defined as:

[0086]

[0087] Based on the characteristics of short-circuit faults, the voltage of the component experiencing a short-circuit fault is 0, while the voltage of other normal components is V. m When a short-circuit fault occurs in the y-th string of the photovoltaic array, the voltage from the top of module (x,y) to the bottom of module (1,y) is represented by V. xy It can be defined as:

[0088]

[0089] When an abnormal aging failure occurs, the voltage of the faulty component is less than V. m However, it is greater than 0. If an abnormal aging fault occurs in the y-th string, the voltage V xy Given:

[0090]

[0091] In the event of a partial shading failure, the voltage of the shaded component is between 0 and V. oc Between. When a partial shading fault occurs in the y-th string, the voltage V xy It can be represented as:

[0092]

[0093] The voltage V of components (a,b) ab Similar to V xy Then the voltage sensor connects component (x,y) and component (a,b), using V ab,xy This means that the following can be calculated:

[0094] V ab,xy =V ab -V xy (6)

[0095] For the subarray, due to the voltage sensor multiplexing method, only (m-1) voltage sensors and bidirectional switches are needed. The input voltage values ​​collected by the voltage sensors are recorded as a voltage vector V. t After time t+1, switch the switch to the other side, collect another series of voltage values, and record them as V. t+1

[0096]

[0097] Where i is the number of voltage sensors, i∈[1,m-1]

[0098] The voltage matrix V can be defined as:

[0099] V = [V t V t+1 (8)

[0100] As stated above, the output voltage of the photovoltaic module is V. m The subarray is in a fault-free state; therefore, the reference voltage V of the subarray is... nor It can be represented as:

[0101]

[0102] Where i = 1, 2, ..., m-1.

[0103] To locate the faulty component in a fault chain, the voltage difference matrix ΔV can be defined as:

[0104]

[0105] The voltage difference matrix ΔV under normal conditions can be calculated as follows:

[0106]

[0107] In this embodiment, the m×n photovoltaic array is divided into n / 3 subarrays. Therefore, locating the fault string is crucial. Assume that the photovoltaic array experiences only one type of fault, and the entire photovoltaic system operates at its maximum power point. As shown in Figure 3(a), string 1 belongs to subarray 1 and serves as the reference string for that subarray.

[0108] Fault string judgment matrix V j It can be defined as

[0109] V j =ΔV - ΔV nor =[ΔV j_t ,ΔV j_t+1 (12)

[0110]

[0111] Furthermore, the fault types include: short-circuit fault, partial shading fault, abnormal aging fault, and open-circuit fault; based on the fault sequence and the fault location rules corresponding to the fault types, component faults are determined, including:

[0112] Obtain the pre-defined mapping relationship between photovoltaic modules and corresponding voltage difference rules under different fault types;

[0113] Set the error coefficient ΔV ε ΔV ε =5%ΔV;

[0114] According to the voltage difference matrix ΔV j，act and the voltage difference ΔV under the fault type corresponding to the mapping relationship. j If |ΔV j,act -ΔV j |<ΔV ε If the corresponding component is faulty, the location of the faulty component will be output.

[0115] Specifically, in this embodiment, the open-circuit fault is addressed as follows:

[0116] For an m×n photovoltaic array, assuming strings 1, 2, and 3 belong to the same subarray, and string 1 is considered a reference string, when string 2 experiences an open-circuit fault while the other two strings are normal, the judgment matrix ΔV is determined. i It can be calculated as:

[0117] V i =ΔV - ΔV nor =[0,ΔV i_t+1 (14)

[0118] For the voltage difference matrix ΔV i calculate,

[0119]

[0120] If both series 1 and series 2 experience open-circuit faults, then ΔV i It can be represented as:

[0121]

[0122] In this embodiment, the photovoltaic array is divided into n / 3 blocks of m×3 subarrays. Since each subarray has a similar structure, we only need to consider the open-circuit fault location method for subarray 1. As shown in Table 1, the second column represents the faulty component, and the other columns represent the measured sensor voltage difference values.

[0123] Table 1. Voltage difference rules for open-circuit faults in subarray 1.

[0124]

[0125] The voltage pattern for open-circuit faults is as follows:

[0126] As mentioned above, string 1 is considered the reference string, and strings 2 and 3 are connected via a bidirectional switch. When string 2 or string 3 fails, the voltage matrix V remains the same; therefore, the voltage effects of strings 1 and 2 are the same as those of strings 1 and 3. The location rules for an open-circuit fault in string 2 are shown in Table 1. When strings 1 and 2 are functioning normally, the voltage sensor detects the voltage from V... 1,1 To V 1,(m-1) Satisfying a mathematical expression V 1,i =(m-2i) / mV pv Let i = 1, 2, ..., m-1, and ΔV i Both are equal to 2 / mV pv When component PV 2,1 When an open circuit fault occurs, the voltage sensor V 1,1 The reading is equal to m-1 / mV pv -V oc Another voltage sensor reading satisfies a mathematical expression V 1,i =(mi) / m-(V) pv -iV oc ) / (mi), i=2,...,m-1, and ΔV1 equals V pv -(m+2)V oc / (m-1)+1 / mV pv From ΔV2 to ΔV i Both are equal to 1 / mV pv -(V pv -V oc ) / (m-1).

[0127] When PV 2,1 Top or PV 2,m An open circuit fault occurs at the bottom, at which point ΔV i Both are equal to 1 / mV pv +V oc It is difficult to locate the fault point, therefore, V is introduced. d Let's solve this problem.

[0128] Vd =V1+V m-1 (17)

[0129]

[0130] If PV 2,1 When an open-circuit fault occurs at the top, the voltage sensor switches from V... 1,1 To V 1,(m-1) To satisfy the mathematical expression V 1,i =(mi)V oc -i / mV pv Let i = 1, 2, ..., m-1, and ΔV i Both are equal to 1 / mV pv +V oc If PV 2,m An open circuit fault occurred at the bottom, and the voltage sensor dropped from V. 1,1 To V 1,(m-1) It satisfies the mathematical expression V 1,i =i / mV pv -(mi)V oc ,i=1,2,...,m-1. If a similar fault occurs in reference string 1, then the fault situation is the same as PV. 2,1 Top and PV 2,m On the opposite side of the bottom, the faulty component can be located via (18).

[0131] Furthermore, in this embodiment, the following applies to short-circuit faults:

[0132] When a short-circuit fault occurs in the subarray, string 1 is fault-free, while string 2 is short-circuited. To locate the faulty component in string 2, the voltage difference ΔV i The calculation formula is as follows:

[0133]

[0134] When both series 2 and series 1 experience short-circuit faults, the voltage difference ΔV i The calculation formula is as follows:

[0135]

[0136] The short-circuit fault location rules will be discussed according to (20) and (21). As described in 3.A, we only need to consider subarray 1. As shown in Table 2, when PV 2,2 When a short circuit fault occurs, the sensor reading V 1,2 Equal to 3 / mV pv -2 / (m-1)V pv The voltage difference ΔV2 is equal to 1 / mV pv Other voltage differences ΔV iThey have the same mathematical relationship, (1 / m + 1 / (m-1))V pv If any component experiences a short circuit, sensor V... 1,i The reading is 1 / mV pv PV 1,i i = 2, 3, ..., m-1, voltage difference ΔV i Equal to 1 / m-1V pv .

[0137] Table 2 Rules for Short-Circuit Fault Voltage Difference in Subarray 1

[0138]

[0139] But when PV 2,1 and PV 2,m-1 When there is a short circuit fault, the voltage difference ΔV i Both are equal to (1 / m + 1 / (m-1))V pv We use V d It can locate faulty components. When PV 2,1 When a short circuit fault occurs, the sensor reading V 2,1 and V 2,m-1 They are respectively equal to (m-1) / mV pv -1 / (m-1)V pv -(m-1) / mV pv Conversely, if PV 2,m-1 When a short circuit fault occurs, sensor V 1,1 and V 1,m-1 They are respectively equal to (m-1) / mV pv ,1 / mV pv -(m-2) / (m-1)V pv Therefore, the faulty component can be located through (23).

[0140] V d =V1+V m-1 (twenty one)

[0141]

[0142] Furthermore, in this embodiment, the abnormal aging fault is addressed as follows:

[0143] Because photovoltaic arrays operate in harsh environments, they are highly susceptible to abnormal aging. Aging failures can lead to increased series resistance or decreased parallel resistance in the photovoltaic modules, and may even cause short-circuit failures. In this embodiment, we only consider simulating aging failures by increasing the series resistance of the photovoltaic modules.

[0144] If series 1 is in normal condition, but series 2 has an abnormal aging fault, then the voltage difference ΔV iIt can be calculated as

[0145]

[0146] Similar to open-circuit and short-circuit faults, we only consider aging faults in subarray 1. The abnormal aging fault location rules of Equation (24) are shown in Table 3.

[0147] Table 3 Voltage Difference Rule 1 for Subarray Abnormal Aging Faults

[0148]

[0149] If component PV 2,1 An abnormal aging fault occurred, and the voltage value of the series 2 photovoltaic modules dropped from V. 1,1 To V 1,m-1 The voltage difference is higher than the corresponding value under normal conditions, but lower than that under short-circuit fault conditions. The voltage difference ΔV2 is 1 / mV. pv <V 1,2 <2 / mV pv Other voltage differences ΔV i Both are equal to (1 / m + 1 / m - 1)V pv <V i <2 / mV pv ,i=1,3,...,m-1.

[0150] When there are PV 2,i When an abnormal aging failure occurs, due to the presence of aging components, the voltage V 1,1 To V 1,m-1 The voltage is greater than the voltage value corresponding to the healthy state, but less than the voltage value corresponding to the short-circuit state. Therefore, the voltage difference ΔV i The voltage difference is greater than that under short-circuit conditions but less than that under normal conditions, making it impossible to locate the faulty component. Similar to open-circuit faults, these two types of faulty components can be distinguished according to the rule (26).

[0151] V d =V1+V m-1 (twenty four)

[0152]

[0153] Furthermore, this embodiment addresses certain shading malfunctions:

[0154] Due to external factors such as weather and dust, the intensity of sunlight received by the photovoltaic array is not uniform. If the irradiance received by a faulty module is close to zero, then that module is equivalent to having an open-circuit fault. In this work, if a module in series 2 experiences a partial shading fault, and the irradiance received by that module is greater than zero but less than 1000 W / m², then... 2 If string 1 is in a normal state, then ΔVi It can be calculated as follows:

[0155] ΔV i =V 1,i -V 1,i+1

[0156]

[0157] Based on the above positioning formula (27), the partial shading fault positioning rules are as follows. As shown in Table 4, if the component PV 2,1 A partial shading fault occurred, and the component voltage dropped from V 2,1 To V 2,m-1 The voltage is greater than the voltage value corresponding to an open-circuit fault, but less than the voltage value corresponding to a short-circuit fault. The voltage difference ranges from ΔV1 to ΔV. i It is greater than the corresponding value for an open circuit fault and less than the corresponding value for a short circuit fault.

[0158] Table 4. Voltage Difference Rules for Partial Shading Faults in Subarray 1

[0159]

[0160] When component PV 2,1 or PV 2,m-1 When there is a partial shading fault, the voltage difference ΔV i Both are equal to 1 / mV p v < V i <2 / mV pv This situation is similar to abnormal aging failure, and the corresponding rules are as follows (29).

[0161] V d =V1+V m-1 (27)

[0162]

[0163] To verify the practicality of the photovoltaic array fault location method proposed in this embodiment, a hardware-in-the-loop simulation was performed on a 37kWp photovoltaic system. Then, the number of voltage sensors and the complexity of the circuit were compared with current fault location methods.

[0164] To verify the effectiveness of the above positioning method, a photovoltaic system based on hardware-in-the-loop simulation was used. The hardware-in-the-loop simulation platform is as follows: Figure 4As shown, a 4×7 photovoltaic array hardware-in-the-loop (HIL) test bench was built. The software was implemented on the StarSim Field-Programmable Gate Array (FPGA) circuit solver (MT FPGA 8000 Solver) and StarSim HIL. Simultaneously, a StarSim Rapid Control Prototyping PXIe-7868R was used as an external controller to control the occurrence of faults and collect voltage data from the voltage sensors. The voltage waveforms during the simulation process can be observed using an oscilloscope.

[0165] In the hardware-in-the-loop simulation, the specifications of each photovoltaic module are as follows: open-circuit voltage (108.5V), short-circuit current (16.75A), MPP point voltage (87V), and MPP point current (15.25A). The external conditions for each photovoltaic module are set as follows: irradiance: 1000W / m². 2 Temperature: 25℃. Figure 5 This is a simulation model for photovoltaic array faults. An open-circuit fault is denoted as "F". O1 “F” O2 “F” O3 A short-circuit fault is represented as "F". S1 “F” S2 “F” S3 Abnormal aging faults are recorded as "F". D1 “F” D2 Partial shading failure is recorded as "F". P1 “F” P2 ".

[0166] Open circuit fault:

[0167] like Figure 5 As shown, the output voltage difference occurs when an open-circuit fault occurs in subarray 1. When the subarray is operating normally, the voltage difference ΔV1~ΔV6 is equal to 173~178V, and V1+V6 equals 0. However, when a fault "F" occurs... O1 "When it occurs, the readings of V1 to ΔV6 are equal and larger than the voltage without a fault, but V1 + V6 is less than 0, satisfying (18), when "F O2 "When the fault occurs, the readings ΔV1~ΔV3, ΔV5, and ΔV6 are greater than the corresponding voltage differences when the fault is normal, but ΔV4 is less than 'no fault,' which is consistent with the case 'PV'." 2,3 "In Table 1. When string 2 has an open-circuit fault, such as "F..." O3 Voltage difference matrix ΔV t With ΔV t+1 They are equivalent; therefore, only one of the voltage difference matrices needs to be considered. When the fault "F..." O3 "When it occurs, ΔV" 1, ΔV2, ΔV4 to ΔV6 are greater than the corresponding voltage difference when healthy, but ΔV3 is less than the voltage difference when there is no fault, which meets the "PV" condition. 2,4 See Table 1.

[0168] In another fault scenario, when the photovoltaic array has two or more open-circuit faults, such as an open-circuit fault "F",... O2 "Occurred in string 1, and another open-circuit fault" F O3 "This occurs in string 2. In this case, the readings of V1 to ΔV3, ΔV5, and ΔV6 are 253V to 258V, ΔV4 is -103V to -101V, and V1 + V6 is less than 0. Therefore, it can be determined that PV..." 1,1 Top and PV 2,4 An open-circuit fault occurred at the bottom. The effectiveness of the proposed positioning strategy was verified under single-string and multi-string open-circuit fault conditions.

[0169] Short circuit fault:

[0170] If a short circuit fault occurs in string 1 of subarray 1, it is denoted as "F". S1 When the fault is not triggered, the voltage difference ΔV1~ΔV6 is 173V~178V, and V1+V2 equals 0; after the fault is triggered, the voltage differences ΔV1, ΔV2, ΔV4~ΔV6 show a significant upward trend, reaching 185V~188V, while the voltage difference ΔV3 decreases to 85~87V, which conforms to the "PV" in Table 2. 2,4 The short-circuit location rule is as follows: If the short-circuit fault occurs in series 3, it is denoted as "F". S2 In this case, the voltage difference ΔV1~ΔV6 is equal to 184~190V, while V1+V2 is less than zero, equal to -102V~-99V. According to (23), the short-circuit fault component can be located at PV. 3,1 When a short circuit fault "F" S3 "Occurred in reference string 2, same as open circuit fault "F O3 The voltage difference ΔV2~ΔV6 is 185~188V, and ΔV1 is 85~87V.

[0171] If a short-circuit fault occurs in different strings, for example, one in string 1 and another in string 2, the voltage differences ΔV2, ΔV4 to ΔV6 are 195V to 200V, and ΔV1 and ΔV3 are 97V to 99V. Therefore, the short-circuit faulty component can be located by observing the voltage differences.

[0172] Abnormal aging fault:

[0173] Calculation as Figure 5 Abnormal aging fault "F" D1The voltage difference ΔV1~ΔV6 is equal to 181V~185V, but V1+V2 is -70V~-69V, which satisfies the fault location rule (26). In the abnormal aging fault "F D2 The voltage difference readings ΔV1, ΔV3~ΔV6 are 181V~191V, and the voltage difference ΔV2 is 113V~119V, which conforms to the "PV" in Table 3. 2,3 The abnormal aging location rule.

[0174] When abnormal aging fault occurs in string 1 ("F") D1 ") and string 2 ("F D2 When V1, V3 to V6 are 190V to 195V, ΔV2 is 119V to 121V, and V1 + V2 is less than zero. Based on the positioning rules in Table 3 of the main text, it is found that the PV component... 1,2 and PV 4,2 Abnormal aging faults also exist. Therefore, the proposed fault location strategy can identify abnormal aging faults within a single string or different strings.

[0175] Partial shading failure:

[0176] Assuming a temperature of 25°C, the photovoltaic array modules are subjected to three states of shading. For example... Figure 5 As shown, when the module experiences partial shading failure, the module receives 800W / m 2 500W / m 2 200W / m 2 When local shading failure "F" P1 "When this occurs, ΔV1~ΔV4 and ΔV6 are 177V~181V, 184V~188V, and 190V~195V respectively, and ΔV5 is equal to 145V~147V, 99V~101V, and 50V~52V respectively. The component PV can be determined by the positioning rules in Table 4 of the appendix." 2,6 A malfunction has occurred. When a partial shading malfunction "F" occurs... P2 "When this occurs, the corresponding voltage differences ΔV1, ΔV3~ΔV6 are 181V~185V, 194V~198V, and 205V~209V respectively, and ΔV2 is equal to 148V~151V, 108V~110V, and 63V~66V respectively."

[0177] Assume that string 2 has a partial shading fault, and string 1 also has the same partial shading fault. When the shading assembly receives a light intensity of 800 W / m²... 2 At this time, the voltage differences ΔV1, ΔV3, ΔV4, and ΔV6 are equal to 180V to 186V, and the values ​​of ΔV2 and ΔV5 are equal to 148V to 151V. When the shading component receives a light intensity of 500W / m²... 2ΔV1, ΔV3, ΔV4, and ΔV6 are 192V to 196V, and ΔV2 and ΔV5 are 107V to 109V. Based on Table 4 and Table 4 in the appendix, PV can be calculated. 3,4 and PV 4,4 There are partial shading faults. Therefore, the positioning method proposed in this embodiment can locate partial shading faults within a single string or different strings.

[0178] Mixed faults:

[0179] In this embodiment, considering the complexity of photovoltaic array faults, we introduce four hybrid fault types to verify the practicality of the proposed method. These include "F..." O F D “F” O F P “F” S F D “F” S F P For example, a subarray may have both open-circuit faults and abnormal aging faults, denoted as "F". O F D The voltage differences ΔV1, ΔV3, ΔV4, and ΔV6 are 262V to 265V, while ΔV2 and ΔV3 are 182V to 185V and -460V to -455V, respectively.

[0180] The subarray has both open-circuit faults and partial shading faults, denoted as "F". O F P "In the case of an open-circuit fault, when the irradiance received by the faulty component is 800W / m." 2 At that time, the voltage difference ΔV3 = -456V to -452V, and ΔV1, ΔV4 to ΔV6 are 256V to 261V, while the irradiance received by the component is 500W / m. 2 At that time, ΔV2 = 223V~226V, ΔV1, ΔV4~ΔV6 are 264V~267V, and ΔV2 is 176V~178V.

[0181] When a subarray simultaneously has both a short-circuit fault and an abnormal aging fault, it is denoted as "F". S F D If there is a short circuit fault in series 1, "F" will be displayed. S1 Furthermore, there is an abnormal aging fault in series 2, with ΔV1, ΔV4~ΔV6 being 191V~194V, ΔV2 being 121V~124V, and ΔV3 being 93V~96V.

[0182] When a subarray simultaneously experiences a short-circuit fault and a partial shading fault, it is denoted as "F". S F P"Under an open-circuit fault condition, when a component receives an irradiance of 800 W / m²..." 2 At that time, the voltage difference ΔV3 is equal to 89V~91V, and ΔV1, ΔV2, ΔV4, and ΔV6 are all 187V~193V, and ΔV5 is 155V~158V; when the irradiance received by the module is 500W / m 2 At that time, the voltage difference ΔV3 = 96V~98V, and ΔV1, ΔV2, ΔV4, ΔV6 are 194V~197V, and the voltage difference ΔV5 is 108V~110V; if the irradiance received by the module drops to 200W / m 2 At that time, the voltage difference ΔV3 is equal to 103V~105V, and ΔV1, ΔV2, ΔV4, ΔV6 are 200V~205V, and ΔV5 is 60V~60V.

[0183] The method proposed in this embodiment can maximize the use of voltage sensors and reduce their number by half. In terms of the number of sensors and the complexity of wiring, the sensor placement strategy proposed in this embodiment has lower complexity.

[0184] In addition, such as Figure 6 As shown, a second aspect of the present invention provides a photovoltaic array fault location system, the system comprising:

[0185] The arrangement module 10 acquires the number of series connections, the number of parallel connections, and the parameters of the photovoltaic array, including the size of the photovoltaic array; determines the number of voltage sensors and bidirectional switches based on the size of the photovoltaic array, and performs voltage sensor arrangement according to preset voltage sensor arrangement rules;

[0186] The data acquisition and diagnostic module 20 acquires the current and voltage of the photovoltaic array under MPP conditions and calculates the power P. act ; Obtain the reference power P under MPP r According to the reference power P r、 Power P act The photovoltaic array is determined to be faulty, and the fault type is determined based on the fault diagnosis.

[0187] The fault location module 30 calculates a voltage difference matrix based on the voltage value measured by the voltage sensor, locates the fault series based on the voltage difference matrix, determines the component fault based on the fault series and the fault location rules corresponding to the fault type, and outputs the location of the faulty component.

[0188] Furthermore, embodiments of this application also disclose an electronic device comprising: one or more processors, and a memory for storing one or more computer programs; characterized in that the computer programs are configured to be executed by the one or more processors, and the programs include steps for performing the photovoltaic array fault location method as described above.

[0189] Furthermore, this application embodiment also provides a storage medium storing a computer program; the program is loaded and executed by a processor to implement the photovoltaic array fault location method steps described above.

[0190] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of each example have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art will use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0191] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation there may be other division methods, such as multiple units or components being combined or integrated into another system, or some features being ignored or not executed. Furthermore, the couplings or direct couplings or communication connections shown or discussed are indirect couplings or communication connections through some interfaces, devices, or units, and may also be electrical, mechanical, or other forms of connection.

[0192] The units described as separate components may or may not be physically separate. As will be apparent to those skilled in the art, the units and algorithm steps of the various examples described in connection with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in terms of function in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art will use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0193] Furthermore, in the various embodiments of this invention, the functional units are integrated into one processing unit, or each unit exists as a separate physical entity, or two or more units are integrated into one unit. The integrated units described above are implemented both in hardware and as software functional units.

[0194] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it is stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, is embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (a personal computer, server, or grid device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media for storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0195] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for locating faults in a photovoltaic array, characterized in that, The method includes: S1, obtain the number of series and parallel connections of the photovoltaic array, as well as the photovoltaic array parameters, including the size of the photovoltaic array; determine the number of voltage sensors and bidirectional switches based on the size of the photovoltaic array, and arrange the voltage sensors according to the preset voltage sensor arrangement rules; S2, collect the current and voltage of the photovoltaic array under MPP, and calculate the power P. act ; Obtain the reference power P under MPP r According to the reference power P r、 Power P act The photovoltaic array is determined to be faulty, and the fault type is determined based on the fault diagnosis. S3. Calculate the voltage difference matrix based on the voltage value measured by the voltage sensor, locate the fault series based on the voltage difference matrix, determine the component fault based on the fault series and the fault location rules corresponding to the fault type, and output the location of the faulty component. The voltage sensor placement is performed according to the preset voltage sensor placement rules, including: Every three adjacent strings form a subarray, and one string is selected as the reference string; the connection between adjacent components in each string of the photovoltaic array is called a node; the nodes of the reference string are cross-connected to the nodes of the other two strings respectively through bidirectional switches; voltage sensors are connected to all nodes; According to the reference power P r、 Power P act The photovoltaic array is determined to have a fault, and the fault type is determined based on fault diagnosis, including: According to the reference power P r Determine power deviation ; If satisfied If the condition persists for a predetermined time threshold, it is determined that there is a potential fault in the photovoltaic array. Fault diagnosis is then used to distinguish the type of fault. The fault series is located based on the voltage difference matrix. Based on the fault series and the fault location rules corresponding to the fault type, the component fault is determined, and the location of the faulty component is output. This includes determining that, under normal conditions, the output voltage of each photovoltaic module at the MPP is V. m ; Total voltage output of the photovoltaic array mV m Therefore, the first y String number x The line voltage is calculated as follows: V xy For the first y The first in the string x The voltage of the components in the row, where m is the number of components connected in series in each string of the photovoltaic array; Based on the characteristics of open-circuit faults, the output voltage of the component experiencing an open-circuit fault is equal to... V oc If the first y If an open circuit fault occurs in the series, the voltage will be... V xy Defined as: ， V pv The total output voltage (mV) of the photovoltaic array m Based on the characteristics of short-circuit faults, the voltage of the component experiencing a short-circuit fault is 0, while the voltage of other normal components is... V m When the photovoltaic array is in its first... y When a short circuit fault occurs in the series, from the component (x, y) Top to component ( 1，y The voltage at the bottom, using V xy It is represented and defined as: ， When an abnormal aging failure occurs, the voltage of the faulty component is less than... V m , but greater than 0; if the first y When a series of wires experiences abnormal aging faults, the voltage V xy Given: In the event of a partial shading failure, the voltage of the shaded component is between 0 and... V oc Between; when the y When a partial shading fault occurs in the series, the voltage V xy It can be represented as: Components a, b The voltage V ab Similar to V xy Then the voltage sensor connection assembly ( x, y) and components ( a, b ),use V ab，xy The calculation is as follows: ， For the subarray, due to the voltage sensor multiplexing method, only ( m -1) A voltage sensor and a bidirectional switch; the input voltage value collected by the voltage sensor is recorded as a voltage vector V. t After time t+1, switch the switch to the other side, collect another series of voltage values, and record them as V. t+1 in, i The number of voltage sensors, ; The voltage matrix V is defined as follows: As described above, the output voltage of the photovoltaic module is V m The subarray is in a fault-free state; therefore, the reference voltage V of the subarray is... nor It can be represented as: in i = 1, 2, ..., m -1; To locate faulty components in a fault chain, a voltage difference matrix is ​​used. It can be defined as: ， Voltage difference matrix under normal conditions The calculation is as follows: ， Fault string judgment matrix V j Defined as: ； The fault types include: short circuit fault, partial shading fault, abnormal aging fault, and open circuit fault; based on the fault sequence and the fault location rules corresponding to the fault types, component faults are determined, including: Obtain the pre-defined mapping relationship between photovoltaic modules and corresponding voltage difference rules under different fault types; Set error coefficient , ; According to the voltage difference matrix and the voltage difference under the fault type corresponding to the mapping relationship ,like If the corresponding component is faulty, the location of the faulty component will be output.

2. A photovoltaic array fault location system, characterized in that, The system includes: The module is configured to acquire the number of series and parallel connections of the photovoltaic array, as well as the photovoltaic array parameters, including the size of the photovoltaic array. Based on the size of the photovoltaic array, the number of voltage sensors and bidirectional switches is determined, and the voltage sensor arrangement is performed according to a preset voltage sensor arrangement rule. The data acquisition and diagnostic module acquires the current and voltage of the photovoltaic array under MPP conditions and calculates the power P. act ; Obtain the reference power P under MPP r According to the reference power P r、 Power P act The photovoltaic array is determined to be faulty, and the fault type is determined based on the fault diagnosis. The fault location module calculates a voltage difference matrix based on the voltage values ​​measured by the voltage sensor, locates the fault series based on the voltage difference matrix, determines the component fault based on the fault series and the fault location rules corresponding to the fault type, and outputs the location of the faulty component. The voltage sensor placement is performed according to the preset voltage sensor placement rules, including: Every three adjacent strings form a subarray, and one string is selected as the reference string; the connection between adjacent components in each string of the photovoltaic array is called a node; the nodes of the reference string are cross-connected to the nodes of the other two strings respectively through bidirectional switches; voltage sensors are connected to all nodes; According to the reference power P r、 Power P act The photovoltaic array is determined to have a fault, and the fault type is determined based on fault diagnosis, including: According to the reference power P r Determine power deviation ; If satisfied If the condition persists for a predetermined time threshold, it is determined that there is a potential fault in the photovoltaic array. Fault diagnosis is then used to distinguish the type of fault. The fault series is located based on the voltage difference matrix. Based on the fault series and the fault location rules corresponding to the fault type, the component fault is determined, and the location of the faulty component is output. This includes determining that, under normal conditions, the output voltage of each photovoltaic module at the MPP is V. m ; Total voltage output of the photovoltaic array mV m Therefore, the first y String number x Horizontal voltage The calculation is as follows: V xy For the first y The first in the string x The voltage of the components in the row; m is the number of components connected in series in each string of the photovoltaic array; Based on the characteristics of open-circuit faults, the output voltage of the component experiencing an open-circuit fault is equal to... V oc If the first y If an open circuit fault occurs in the series, the voltage will be... V xy Defined as: ， V pv The total output voltage (mV) of the photovoltaic array m Based on the characteristics of short-circuit faults, the voltage of the component experiencing a short-circuit fault is 0, while the voltage of other normal components is... V m When the photovoltaic array is in its first... y When a short circuit fault occurs in the series, from the component (x, y) Top to component ( 1，y The voltage at the bottom, using V xy It is represented and defined as: ， When an abnormal aging failure occurs, the voltage of the faulty component is less than... V m , but greater than 0; if the first y When a series of wires experiences abnormal aging faults, the voltage V xy Given: In the event of a partial shading failure, the voltage of the shaded component is between 0 and... V oc Between; when the y When a partial shading fault occurs in the series, the voltage V xy It can be represented as: Components a, b The voltage V ab Similar to V xy Then the voltage sensor connection assembly ( x, y) and components ( a, b ),use V ab，xy The calculation is as follows: ， For the subarray, due to the voltage sensor multiplexing method, only ( m -1) A voltage sensor and a bidirectional switch; the input voltage value collected by the voltage sensor is recorded as a voltage vector V. t After time t+1, switch the switch to the other side, collect another series of voltage values, and record them as V. t+1 in, i The number of voltage sensors, ; The voltage matrix V is defined as follows: As described above, the output voltage of the photovoltaic module is V m The subarray is in a fault-free state; therefore, the reference voltage V of the subarray is... nor It can be represented as: ， in i = 1, 2, ..., m -1; To locate faulty components in a fault chain, a voltage difference matrix is ​​used. It can be defined as: ， Voltage difference matrix under normal conditions The calculation is as follows: ， Fault string judgment matrix V j Defined as: ； The fault types include: short circuit fault, partial shading fault, abnormal aging fault, and open circuit fault; based on the fault sequence and the fault location rules corresponding to the fault types, component faults are determined, including: Obtain the pre-defined mapping relationship between photovoltaic modules and corresponding voltage difference rules under different fault types; Set error coefficient , ; According to the voltage difference matrix and the voltage difference under the fault type corresponding to the mapping relationship ,like If the corresponding component is faulty, the location of the faulty component will be output.

3. An electronic device, the electronic device comprising: One or more processors, a memory for storing one or more computer programs; characterized in that the computer programs are configured to be executed by the one or more processors, the programs including steps for performing the photovoltaic array fault location method as claimed in claim 1.

4. A storage medium storing a computer program, characterized in that, The program is loaded and executed by a processor to implement the steps of the photovoltaic array fault location method as described in claim 1.

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