Island detection method, system and device based on multiple parameters and storage medium

Abstract

The invention discloses an island detection method, system and device based on multiple parameters and a storage medium, and the key points of the technical scheme are that the method comprises the steps: carrying out the sampling of a grid connection point of a distributed power supply, and obtaining a voltage signal and a current signal; calculating to obtain a phase angle change rate according to the voltage signal and the current signal, and calculating to obtain a measurement frequency, a frequency change rate and a voltage change rate according to the voltage signal; obtaining an intermediate judgment result according to the measurement frequency and the frequency change rate; and judging whether an island occurs or not according to the intermediate judgment result, the voltage change rate and the phase angle change rate. According to the invention, missed judgment and misjudgment are reduced, and safe and efficient detection is maintained in an actual island state.

Description

Technical Field

[0001] The present invention belongs to the technical field of power grid monitoring, and in particular relates to a multi-parameter based island detection method, system, device and storage medium. Background Art

[0002] Islanding refers to a situation where distributed generation (DG) continues to supply power to certain parts of the system even after the main grid system is disconnected due to any disturbance or fault on the grid side. DGs are connected to the main grid via inverters. When the main grid is disconnected due to a fault, the local loads and DGs form a self-sufficient, isolated system. Unintended islanding can not only damage electrical equipment in the system but also pose a safety threat to personnel involved.

[0003] Currently available islanding detection methods typically employ passive approaches, utilizing a single electrical parameter acquired from the system and correlating the measured value with a predetermined threshold to generate a trip signal. Consequently, many existing passive islanding detection methods can lead to false detections when any unusual changes in the system configuration occur. Summary of the Invention

[0004] The purpose of the present invention is to provide a multi-parameter based island detection method, system, device and storage medium to reduce missed detection and misjudgment, and maintain safe and efficient detection in actual islanding conditions.

[0005] A first aspect of the present invention provides a multi-parameter based island detection method, comprising:

[0006] Sampling the grid connection point of the distributed power supply to obtain voltage and current signals;

[0007] Calculate the phase angle change rate based on the voltage signal and the current signal, and calculate the measurement frequency, the frequency change rate, and the voltage change rate based on the voltage signal;

[0008] Obtaining an intermediate determination result according to the measured frequency and the frequency change rate;

[0009] Whether islanding occurs is determined based on the intermediate determination result, the voltage change rate, and the phase angle change rate.

[0010] In some embodiments, obtaining an intermediate determination result according to the measured frequency and the frequency change rate includes:

[0011] Determining whether the measurement frequency exceeds a first preset range;

[0012] If so, determining whether the frequency change rate exceeds a second preset range; if so, obtaining an intermediate determination result of true; if not, obtaining an intermediate determination result of false;

[0013] If not, the intermediate determination result is false.

[0014] In some embodiments, determining whether islanding occurs based on the intermediate determination result, the voltage change rate, and the phase angle change rate includes:

[0015] If the intermediate determination result is true, determining whether the voltage change rate exceeds a third preset range, if so, determining that islanding occurs, if not, determining that a grid transient occurs;

[0016] If the intermediate determination result is false, it is determined whether the phase angle change rate exceeds a fourth preset range. If so, it is determined that islanding occurs; if not, it is determined that neither islanding nor grid transient occurs.

[0017] In some embodiments, calculating the phase angle change rate based on the voltage signal and the current signal includes:

[0018] Calculating a first phase difference between a voltage phase angle and a current phase angle based on the voltage signal and the current signal at the current moment;

[0019] Calculating a second phase difference between a voltage phase angle and a current phase angle according to the voltage signal and the current signal at the target moment;

[0020] The phase angle change rate is calculated based on the first phase difference, the second phase difference, and the time difference between the current moment and the target moment.

[0021] In some embodiments, the method for calculating the voltage phase angle and the current phase angle includes:

[0022] Performing a Clarke transform on the voltage signal to obtain a first voltage component and a second voltage component in a stationary coordinate system, wherein the voltage signal includes a three-phase voltage signal;

[0023] Calculating a voltage phase angle according to the first voltage component and the second voltage component;

[0024] performing a Clarke transform on the current signal to obtain a first current component and a second current component in a stationary coordinate system, and performing a Park transform on the first current component and the second current component according to the voltage phase angle to obtain a third current component and a fourth current component in a rotating coordinate system, wherein the current signal includes a three-phase current signal;

[0025] A current phase angle is calculated based on the third current component and the fourth current component.

[0026] In some embodiments, calculating the frequency change rate according to the voltage signal includes:

[0027] extracting a fundamental frequency signal according to the voltage signal;

[0028] Performing a differential calculation on the fundamental frequency signal to obtain a differential result;

[0029] The differential result of the base frequency signal is input into a first-order low-pass filter to obtain the frequency change rate.

[0030] In some embodiments, calculating the voltage change rate according to the voltage signal includes:

[0031] Obtaining a first voltage at the current moment according to the voltage signal at the current moment;

[0032] obtaining a second voltage at the target moment according to the voltage signal at the target moment;

[0033] A voltage difference between the first voltage and the second voltage is calculated, a time difference between the current moment and the target moment is calculated, and a voltage change rate is calculated based on the voltage difference and the time difference.

[0034] A second aspect of the present invention provides an island detection system based on multiple parameters, comprising:

[0035] The sampling module is used to sample the grid connection point of the distributed power supply to obtain voltage and current signals;

[0036] a calculation module, configured to calculate a phase angle change rate based on the voltage signal and the current signal, and to calculate a measurement frequency, a frequency change rate, and a voltage change rate based on the voltage signal;

[0037] A first judgment module is used to obtain an intermediate judgment result according to the measured frequency and the frequency change rate;

[0038] The second judgment module is used to judge whether islanding occurs according to the intermediate judgment result, the voltage change rate and the phase angle change rate.

[0039] A third aspect of the present invention provides a computer device, comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the above method when executing the computer program.

[0040] A fourth aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program implements the steps of the above method when executed by a processor.

[0041] The technical solution provided by the present invention has the following advantages and effects: the frequency change rate, voltage change rate, measurement frequency, and phase angle change rate can be used to identify whether an island exists, and whether an island occurs is determined based on the intermediate judgment result, the voltage change rate, and the phase angle change rate. By monitoring the phase angle change rate, the frequency change rate, voltage change rate, and measurement frequency are compensated for the missed judgment of islanding conditions with smaller power imbalances. By monitoring the voltage change rate, the frequency change rate, phase angle change rate, and measurement frequency are compensated for the misjudgment of grid-connected scenarios with rapidly changing system faults, thereby maintaining safe and efficient detection in actual islanding conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 1 is a flow chart of the multi-parameter based island detection method provided by the present invention;

[0043] Figure 2 This is a schematic diagram of the connection between the photovoltaic-based distributed power supply and the main power grid provided by the present invention;

[0044] Figure 3 is a flow chart of step S3 provided by the present invention;

[0045] Figure 4 It is a structural block diagram of the multi-parameter based island detection system provided by the present invention;

[0046] Figure 5 It is a diagram of the internal structure of a computer device provided by an embodiment of the present invention.

[0047] 1. Distributed light source; 11. Photovoltaic array; 12. Inverter; 2. Local load; 3. Main grid. DETAILED DESCRIPTION

[0048] To facilitate understanding of the present invention, specific embodiments of the present invention will be described in more detail below with reference to the accompanying drawings.

[0049] Unless otherwise specified or defined, the "first, second..." used in this article is only used to distinguish names and does not represent a specific quantity or order.

[0050] Unless stated otherwise or defined otherwise, the term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0051] It should be noted that, in this document, “fixed to” or “connected to” may mean directly fixing or connecting to an element, or indirectly fixing or connecting to an element.

[0052] like Figure 1 As shown, this embodiment provides a multi-parameter based island detection method, including the following steps S1 to S4:

[0053] Step S1: sampling the grid connection point of the distributed power supply to obtain voltage and current signals.

[0054] In practical applications, such as Figure 2 The figure shows a schematic diagram of the connection between a photovoltaic-based distributed power source and the main power grid. The distributed power source is connected to the main power grid via an inverter. The PCC represents the grid connection point. Periodic sampling of the grid connection point generates three-phase voltage signals and three-phase current signals. In other embodiments, the distributed power source can be other distributed power sources based on wind power, hydropower, or fuel cells.

[0055] Step S2: Calculate the phase angle change rate based on the voltage signal and the current signal, and calculate the measurement frequency, the frequency change rate, and the voltage change rate based on the voltage signal.

[0056] In practical applications, by calculating and measuring any one of the parameters of frequency, frequency change rate, voltage change rate, and phase angle change rate, and then comparing the parameter with a preset range, if the parameter exceeds the preset range, it is determined that an islanding event has occurred. However, only measuring any one of the parameters of frequency, frequency change rate, voltage change rate, and phase angle change rate will usually result in misjudgment or missed judgment, affecting the security of the power grid. Therefore, the present application determines whether a distributed power source has islanded based on multiple parameters by calculating and measuring frequency, frequency change rate, voltage change rate, and phase angle change rate, thereby improving the ability to distinguish between true islanding events and non-islanding interference (such as load changes or power grid transients).

[0057] Specifically, calculating the phase angle change rate according to the voltage signal and the current signal includes:

[0058] Calculating a first phase difference between a voltage phase angle and a current phase angle based on the voltage signal and the current signal at the current moment;

[0059] Calculating a second phase difference between a voltage phase angle and a current phase angle according to the voltage signal and the current signal at the target moment;

[0060] The phase angle change rate is calculated based on the first phase difference, the second phase difference, and the time difference between the current moment and the target moment.

[0061] The method for calculating the voltage phase angle and the current phase angle includes:

[0062] Performing a Clarke transform on the voltage signal to obtain a first voltage component and a second voltage component in a stationary coordinate system, wherein the voltage signal includes a three-phase voltage signal;

[0063] Calculating a voltage phase angle according to the first voltage component and the second voltage component;

[0064] performing a Clarke transform on the current signal to obtain a first current component and a second current component in a stationary coordinate system, and performing a Park transform on the first current component and the second current component according to the voltage phase angle to obtain a third current component and a fourth current component in a rotating coordinate system, wherein the current signal includes a three-phase current signal;

[0065] A current phase angle is calculated based on the third current component and the fourth current component.

[0066] In practical applications, Clarke transformation is performed on the three-phase voltages Va, Vb, and Vc to obtain the first voltage component of the α-axis and the second voltage component of the β-axis in the stationary coordinate system (αβ). The voltage phase angle is calculated using the voltage phase angle calculation formula, which is:

[0067]

[0068] Among them, θ v Indicates the voltage phase angle, V α Represents the first voltage component, V β represents the second voltage component; the first voltage component and the second voltage component are substituted into the voltage phase angle calculation formula to obtain the voltage phase angle.

[0069] Specifically, the three-phase currents Ia, Ib, and Ic are subjected to a Clarke transform to obtain a first current component of the α-axis and a second current component of the β-axis in a stationary coordinate system (αβ). Then, the first and second current components in the stationary coordinate system are subjected to a Park transform according to the voltage phase angle to obtain a third voltage component of the d-axis and a fourth voltage component of the q-axis in a rotating coordinate system (dq). The current phase angle is calculated using a current phase angle calculation formula, which is:

[0070]

[0071] Among them, θ i Represents the current phase angle, I d Represents the third current component, I q represents the fourth current component; the first current component and the second current component are subjected to Park transformation by using the voltage phase angle to ensure that the voltage and the current are compared in the same rotating reference frame, and the first phase difference at the current moment and the second phase difference at the target moment are calculated. The current moment represents the moment corresponding to the n+1th sampling point, the target moment represents the moment corresponding to the nth sampling point, and the time difference between the current moment and the target moment represents the sampling period. The phase angle change rate is calculated by the phase angle change rate calculation formula, and the phase angle change rate calculation formula is:

[0072]

[0073] Wherein, ROCOPAD represents the rate of change of phase angle, Δ(θ v -θ i ) represents the difference between the first phase difference and the second phase difference, and Δt represents the time difference between the current moment and the target moment.

[0074] Specifically, the measurement frequency can be measured by a synchronized phasor measurement device to obtain the measurement frequency of the grid connection point, and the frequency change rate is calculated according to the voltage signal, including:

[0075] extracting a fundamental frequency signal according to the voltage signal;

[0076] Performing a differential calculation on the fundamental frequency signal to obtain a differential result;

[0077] The differential result of the base frequency signal is input into a first-order low-pass filter to obtain the frequency change rate.

[0078] In practical applications, the fundamental frequency signal of the voltage signal is extracted through a phase-locked loop. The phase-locked loop is constructed based on the voltage phase angle to phase-lock the grid voltage phase, and the fundamental frequency signal is differentiated to obtain the differential result of the fundamental frequency signal. The differential result is then filtered to obtain the frequency change rate ROCOF, which effectively eliminates high-frequency components (such as switching noise and harmonic interference) and improves the signal-to-noise ratio of the frequency change rate.

[0079] Specifically, calculating the voltage change rate according to the voltage signal includes:

[0080] Obtaining a first voltage at the current moment according to the voltage signal at the current moment;

[0081] obtaining a second voltage at the target moment according to the voltage signal at the target moment;

[0082] A voltage difference between the first voltage and the second voltage is calculated, a time difference between the current moment and the target moment is calculated, and a voltage change rate is calculated based on the voltage difference and the time difference.

[0083] In practical applications, if distributed generation continues to supply power to local loads when the main grid is disconnected, this can cause abnormal voltage and frequency fluctuations. In the event of a power imbalance between the load and the source, the voltage may rise or fall rapidly, causing transients in an islanding state. In the event of a power imbalance, islanding can be detected by monitoring the voltage change rate.

[0084] Step S3: Obtain an intermediate determination result according to the measured frequency and the frequency change rate.

[0085] Specifically, the measured frequency at the grid connection point can be measured using a synchronized phasor measurement device. The measured frequency, which is the AC power frequency, is typically 50 or 60 Hz and remains constant. However, disturbances caused by sudden imbalances or faults can cause frequency deviations. When the measured frequency exceeds a predefined upper limit, an overfrequency event occurs; when the measured frequency falls below a predefined lower limit, an underfrequency event occurs. These overfrequency and underfrequency conditions can lead to islanding.

[0086] Specifically, if Figure 3 As shown, obtaining an intermediate determination result according to the measured frequency and the frequency change rate includes:

[0087] Determining whether the measurement frequency exceeds a first preset range;

[0088] If so, determining whether the frequency change rate exceeds a second preset range; if so, obtaining an intermediate determination result of true; if not, obtaining an intermediate determination result of false;

[0089] If not, the intermediate determination result is false.

[0090] In actual applications, the upper limit of the first preset range is the upper limit of the grid frequency, and the lower limit of the first preset range is the lower limit of the grid frequency. If the measured frequency is within the first preset range, it indicates that the measured frequency is within the normal range, the intermediate determination result is recorded as false, and normal sampling of the grid connection point continues. If it exceeds the first preset range, overfrequency or underfrequency is determined to have occurred, and islanding may occur. Therefore, it is necessary to further determine whether islanding has occurred by combining the frequency change rate, voltage change rate, and phase angle change rate.

[0091] The frequency rate of change is one factor that can change during an islanding situation. During normal grid-connected operation, the frequency is strictly maintained by the main grid (e.g., 50 Hz in China). Active power fluctuations from distributed generation (DGs) are absorbed or supplemented by the grid, resulting in minimal frequency fluctuations. When the grid is disconnected, the islanded system (DGs + local loads) must balance its active power. If the DG output power exceeds the load power, the system frequency rises; if the DG output power is less than the load power, the system frequency falls. The frequency rate of change is proportional to the amount of active power imbalance. Monitoring the frequency rate of change can further determine whether an islanding situation has occurred. If the measured frequency exceeds a first preset range, the frequency rate of change is further determined to be within a second preset range. If the frequency rate of change exceeds the second preset range, the intermediate determination is true; if the frequency rate of change is within the second preset range, the intermediate determination is false. After obtaining the intermediate determination, the voltage rate of change and the phase angle rate of change are combined to further determine whether an islanding situation has occurred. Combining frequency and frequency rate of change measurements can reduce false islanding detection errors.

[0092] Step S4: Determine whether islanding occurs based on the intermediate determination result, the voltage change rate, and the phase angle change rate.

[0093] Specifically, judging whether islanding occurs based on the intermediate determination result, the voltage change rate, and the phase angle change rate includes:

[0094] If the intermediate determination result is true, determining whether the voltage change rate exceeds a third preset range, if so, determining that islanding occurs, if not, determining that a grid transient occurs;

[0095] If the intermediate determination result is false, it is determined whether the phase angle change rate exceeds a fourth preset range. If so, it is determined that islanding occurs; if not, it is determined that neither islanding nor grid transient occurs.

[0096] In practical applications, monitoring the voltage rate of change can often determine whether islanding has occurred in the presence of power imbalance. However, using the voltage rate of change alone can easily lead to misjudgments due to system characteristic adjustments. Furthermore, if the power imbalance in an islanding system is small, the voltage at the grid connection point will fluctuate steadily, making islanding detection based solely on the voltage rate of change ineffective. Therefore, it is necessary to further determine whether islanding has occurred by combining the intermediate determination result. If the intermediate determination result is true and the voltage rate of change exceeds the third preset range, islanding is determined to have occurred.

[0097] In actual applications, if islanding occurs in the presence of a severe power imbalance, the voltage and frequency will change significantly. Therefore, the rate of change of frequency (ROCOF), the rate of change of voltage (ROCOV), and over / underfrequency (OF / UF) can be used to identify whether an islanding condition exists. As long as the intermediate determination result is true and the voltage change rate exceeds the third preset range, an islanding condition is determined to have occurred, triggering a final power-off operation. In the case of an islanding condition with a smaller power imbalance, the voltage and frequency may not change significantly, the intermediate determination result may be false, and the islanding condition may not be identified by ROCOF, ROCOV, and OF / UF. However, even if the power imbalance is extremely small, the phase angle changes of the voltage and current will increase. Therefore, when the intermediate determination result is false and the value of the phase angle change rate (ROCPAD) exceeds the fourth preset range, an islanding condition is determined to have occurred, triggering a final power-off operation. While ROCOF and OF / UF may cause malfunctions in grid-connected scenarios with rapidly changing system faults, the final power-off operation is limited by ROCOV. If the intermediate determination result is true but ROCOV is within the fourth preset range, a grid transient is determined to have occurred. A grid transient refers to the process in which system parameters (such as current and frequency) undergo instantaneous changes after a sudden fault or external disturbance (such as a short circuit or sudden load change) in the grid system. A multi-parameter islanding detection method based on frequency rate of change, voltage rate of change, over / underfrequency, and phase angle rate of change enables safe and efficient detection in actual islanding conditions.

[0098] like Figure 4 As shown, an embodiment of the present invention further provides an island detection system based on multiple parameters, including:

[0099] The sampling module 10 is used to sample the grid connection point of the distributed power supply to obtain voltage and current signals;

[0100] a calculation module 20, configured to calculate a measurement frequency, a frequency change rate, and a voltage change rate based on the voltage signal, and to calculate a phase angle change rate based on the voltage signal and the current signal;

[0101] A first judgment module 30 is configured to obtain an intermediate judgment result based on the measured frequency and the frequency change rate;

[0102] The second judgment module 40 is configured to judge whether islanding occurs based on the intermediate judgment result, the voltage change rate, and the phase angle change rate.

[0103] Each module of the multi-parameter island detection system can be implemented in whole or in part through software, hardware, or a combination thereof. Each of the modules and units can be embedded in or independent of a processor within a computer device in hardware form, or stored in a computer device memory in software form, so that the processor can call and execute the corresponding operations of each module.

[0104] like Figure 5 As shown, an embodiment of the present invention discloses a computer device, including a memory and a processor, wherein the memory stores a computer program;

[0105] The computer device may be a server, and its internal structure diagram may be as follows: Figure 5 As shown. The computer device includes a processor, memory, network interface, and database connected via a system bus. 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 computer program in the non-volatile storage medium. The network interface of the computer device is used to communicate with an external terminal via a network connection. When the computer program is executed by the processor, it implements the multi-parameter-based island detection method described in the above embodiments.

[0106] Those skilled in the art will understand that Figure 5 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 shown in the figure, or combine certain components, or have a different component arrangement.

[0107] An embodiment of the present invention further discloses a computer-readable storage medium storing a computer program, wherein the computer program enables a computer to execute the multi-parameter-based island detection method described in the above embodiments.

[0108] Those skilled in the art will appreciate that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program. 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 memory, storage, database or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0109] The technical features of the above embodiments can 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 specification.

Claims

1. The island detection method based on multiple parameters is characterized by: include: Sampling the grid connection point of the distributed power supply to obtain voltage and current signals; Calculate the phase angle change rate based on the voltage signal and the current signal, and calculate the measurement frequency, the frequency change rate, and the voltage change rate based on the voltage signal; Obtaining an intermediate determination result according to the measured frequency and the frequency change rate; Whether islanding occurs is determined based on the intermediate determination result, the voltage change rate, and the phase angle change rate.

2. The multi-parameter island detection method according to claim 1, wherein: Obtaining an intermediate determination result according to the measured frequency and the frequency change rate includes: Determining whether the measurement frequency exceeds a first preset range; If so, determining whether the frequency change rate exceeds a second preset range; if so, obtaining an intermediate determination result of true; if not, obtaining an intermediate determination result of false; If not, the intermediate determination result is false.

3. The multi-parameter island detection method according to claim 1, wherein: The determining whether islanding occurs based on the intermediate determination result, the voltage change rate, and the phase angle change rate includes: If the intermediate determination result is true, determining whether the voltage change rate exceeds a third preset range, if so, determining that islanding occurs, if not, determining that a grid transient occurs; If the intermediate determination result is false, it is determined whether the phase angle change rate exceeds a fourth preset range. If so, it is determined that islanding occurs; if not, it is determined that neither islanding nor grid transient occurs.

4. The multi-parameter island detection method according to claim 1, wherein: The calculating the phase angle change rate according to the voltage signal and the current signal includes: Calculating a first phase difference between a voltage phase angle and a current phase angle based on the voltage signal and the current signal at the current moment; Calculating a second phase difference between a voltage phase angle and a current phase angle according to the voltage signal and the current signal at the target moment; The phase angle change rate is calculated based on the first phase difference, the second phase difference, and the time difference between the current moment and the target moment.

5. The multi-parameter island detection method according to claim 4, wherein: The method for calculating the voltage phase angle and the current phase angle includes: Performing a Clarke transform on the voltage signal to obtain a first voltage component and a second voltage component in a stationary coordinate system, wherein the voltage signal includes a three-phase voltage signal; Calculating a voltage phase angle according to the first voltage component and the second voltage component; performing a Clarke transform on the current signal to obtain a first current component and a second current component in a stationary coordinate system, and performing a Park transform on the first current component and the second current component according to the voltage phase angle to obtain a third current component and a fourth current component in a rotating coordinate system, wherein the current signal includes a three-phase current signal; A current phase angle is calculated based on the third current component and the fourth current component.

6. The multi-parameter island detection method according to claim 1, wherein: The frequency change rate is calculated according to the voltage signal, including: extracting a fundamental frequency signal according to the voltage signal; Performing a differential calculation on the fundamental frequency signal to obtain a differential result; The differential result of the base frequency signal is input into a first-order low-pass filter to obtain the frequency change rate.

7. The multi-parameter island detection method according to claim 1, wherein: Calculating the voltage change rate according to the voltage signal includes: Obtaining a first voltage at the current moment according to the voltage signal at the current moment; obtaining a second voltage at the target moment according to the voltage signal at the target moment; A voltage difference between the first voltage and the second voltage is calculated, a time difference between the current moment and the target moment is calculated, and a voltage change rate is calculated based on the voltage difference and the time difference.

8. The island detection system based on multiple parameters is characterized by: include: The sampling module is used to sample the grid connection point of the distributed power supply to obtain voltage and current signals; a calculation module, configured to calculate a phase angle change rate based on the voltage signal and the current signal, and to calculate a measurement frequency, a frequency change rate, and a voltage change rate based on the voltage signal; A first judgment module is used to obtain an intermediate judgment result according to the measured frequency and the frequency change rate; The second judgment module is used to judge whether islanding occurs according to the intermediate judgment result, the voltage change rate and the phase angle change rate.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: 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.

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