A power grid monitoring system, device, computer equipment and storage medium

Abstract

The present application relates to a power grid monitoring system, device, computer equipment and storage medium. The power grid monitoring system includes a power generation device, a distribution network, an inverter, a measuring device and an intelligent gateway; the measuring device is used to inject a measurement signal into the output end of the inverter and the first input end of the distribution network to measure the power parameters of the output end and the first input end of the inverter; the power parameters of the output end of the inverter, the power parameters of the first input end and the power parameters of the measurement signal are sent to the intelligent gateway; the intelligent gateway is used to determine the impedance interaction phase angle margin between the inverter and the distribution network according to the power parameters of the output end of the inverter, the power parameters of the first input end and the power parameters of the measurement signal, and can also send a parameter adjustment strategy to the inverter according to the impedance interaction phase angle margin, instructing the inverter to adjust the equivalent output impedance according to the digital adjustment strategy. The use of this method can monitor the stability of the power grid operation and ensure the continuous and stable operation of the power grid.

Description

Technical Field

[0001] The present application relates to the technical field of power distribution networks, and in particular to a power grid monitoring system, device, computer equipment and storage medium. Background Art

[0002] Renewable energy is increasingly being used in power grids. By connecting renewable energy to the grid through inverters, renewable energy grids have gradually emerged. In order to ensure the safe and stable operation of renewable energy grids, it is necessary to monitor and control the operation of renewable energy grids.

[0003] As more and more renewable energy sources are integrated into the distribution network, changes in the impedance of the inverter and the impedance of the grid itself may affect the stable operation of the grid. This is mainly reflected in the fact that the grid operation mode may switch at any time. Changes in the grid operation mode will cause changes in the impedance of the grid itself. Changes in the output power of renewable energy power generation devices will cause changes in the impedance of the inverter, which may cause the grid to be unable to operate stably and continuously. Summary of the invention

[0004] Based on this, it is necessary to provide a power grid monitoring system, device, computer equipment and storage medium to address the above technical problems, which can monitor the impedance interaction phase margin of the inverter and distribution network at the renewable energy power generation end, so as to monitor the stability of the power grid operation according to the impedance interaction phase margin and ensure the continuous and stable operation of the power grid.

[0005] A power grid monitoring system, comprising:

[0006] Power generation equipment, distribution network, inverter, measurement equipment and intelligent gateway.

[0007] The measuring device is used to measure the power parameters of the output end of the inverter and the first input end after injecting a measuring signal into the output end of the inverter and the first input end of the distribution network; the first input end is the input end corresponding to the distribution network and the power generation device;

[0008] The measuring device is also used to send the power parameters of the output end of the inverter, the power parameters of the first input end, and the power parameters of the measurement signal to the intelligent gateway;

[0009] The intelligent gateway is used to receive the power parameters of the output end of the inverter, the power parameters of the first input end, and the power parameters of the measurement signal sent by the measuring device, and determine the impedance interaction phase angle margin between the inverter and the distribution network according to the power parameters of the output end of the inverter, the power parameters of the first input end, and the power parameters of the measurement signal;

[0010] The intelligent gateway is also used to determine a parameter adjustment strategy of the inverter according to the impedance interaction phase margin value, and send the parameter adjustment strategy to the inverter, where the parameter adjustment strategy is used to instruct the inverter to adjust the equivalent output impedance according to the parameter adjustment strategy.

[0011] The above-mentioned power grid monitoring system, device, computer equipment and storage medium inject a measurement signal into the output end of the inverter and the first input end of the distribution network through a measuring device to measure the power parameters of the output end of the inverter and the power parameters of the first input end; the first input end is the input end corresponding to the distribution network and the power source; then, the measuring device sends the power parameters of the output end of the inverter, the power parameters of the first input end and the power parameters of the measurement signal to the intelligent gateway; the intelligent gateway receives the power parameters of the output end of the inverter, the power parameters of the first input end and the power parameters of the measurement signal sent by the measuring device, and determines the impedance interaction phase angle margin between the inverter and the distribution network according to the power parameters of the output end of the inverter, the power parameters of the first input end and the power parameters of the measurement signal; finally, the intelligent gateway determines the parameter adjustment strategy of the inverter according to the impedance interaction phase angle margin, and the parameter adjustment strategy is used to instruct the inverter to adjust the equivalent output impedance according to the parameter adjustment strategy, so as to ensure the continuous and stable operation of the power grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 A schematic diagram of an application environment of a power grid monitoring system provided in an embodiment of the present application;

[0013] Figure 2 A schematic diagram of the interaction of power grid monitoring system equipment provided in an embodiment of the present application;

[0014] Figure 3 A schematic diagram of a flow chart of a power grid monitoring system provided in an embodiment of the present application;

[0015] Figure 4 A schematic diagram of a flow chart of a power grid monitoring system provided in an embodiment of the present application;

[0016] Figure 5 A schematic diagram of phase margin calculation of a power grid monitoring system provided in an embodiment of the present application;

[0017] Figure 6 A schematic diagram of a flow chart of a power grid monitoring system provided in an embodiment of the present application;

[0018] Figure 7 A schematic diagram of a method flow of a power grid monitoring system is provided for an embodiment of the present application;

[0019] Figure 8 A block diagram of the structure of the intelligent gateway provided in the embodiment of the present application;

[0020] Fig. 9This is a diagram of the internal structure of a computer device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0022] The power grid monitoring system provided in the embodiment of the present application can be applied to Figure 1 The power distribution network shown. Figure 1 , the distribution network may include: a physical grid of the power grid, an intelligent gateway, a measuring device, a power generation device, an inverter, etc. Among them, the physical grid of the power grid includes lines, circuit breakers (CB0), switches (QF1, ..., QFK) and several loads. The power generation device is used to convert other forms of energy into electrical energy. The power generation device can be a traditional energy power generation device or a new energy power generation device. For example, the new energy power generation device can be a wind power generation device or a photovoltaic power generation device, etc., which is not limited in the embodiments of the present application. Figure 1 In this paper, only single-phase photovoltaic power generation (PV 1,…,PV k) is taken as an example.

[0023] Inverters are used to input power generation into the physical grid of the power grid.

[0024] The smart gateway can be a server based on edge computing, which can interact with other devices in the distribution network. The interaction method includes but is not limited to wired communication or wireless communication.

[0025] The measuring device may be capable of injecting voltage signals or current signals into both sides of the grid-connected point of the inverter in the distribution network, and may also measure the voltage or current on both sides of the grid-connected point.

[0026] In one embodiment, Figure 1 The various devices in the system shown can monitor the operation status of the power grid through interaction. Figure 2 ,The grid monitoring system includes power generation equipment, distribution network, inverter, measuring equipment and intelligent gateway.

[0027] Exemplarily, the measuring device may inject a measuring signal into the output terminal of the inverter and the first input terminal of the distribution network. After the measuring device injects the measuring signal, the voltage or current of the output terminal of the inverter and the first input terminal of the distribution network may change. The measuring device may also measure the current or voltage before and after the output terminal of the inverter and the first input terminal of the distribution network. Specifically, after the measuring device injects the measuring signal into the output terminal of the inverter and the first input terminal of the distribution network, it may measure the power parameters of the output terminal of the inverter and the power parameters of the first input terminal.

[0028] In a possible implementation, the power parameter may be voltage or current. The first input terminal of the distribution network may be an input terminal corresponding to the distribution network and the power generation device, that is, an end where the distribution network and the inverter are connected.

[0029] The measuring device can inject a measuring signal into both sides of the inverter grid connection point in the distribution network and measure the voltage or current on both sides of the inverter grid connection point. The measuring signal can be a voltage disturbance signal or a current disturbance signal.

[0030] In a specific implementation, when the measurement signal is a voltage disturbance signal, the measuring device also measures the current values ​​of the inverter and the output of the first input terminal before and after the voltage disturbance signal is injected; in this implementation, the power parameters of the output terminal of the inverter and the first input terminal of the distribution network are currents.

[0031] When the measurement signal is a current disturbance signal, the measurement device also measures the voltage values ​​of the inverter and the first input and output ends before and after the current disturbance signal is injected.

[0032] In this implementation, the power parameter at the output end of the inverter and the first input end of the power distribution network is voltage.

[0033] The measuring device is also used to send the power parameters of the output end of the inverter, the power parameters of the first input end and the power parameters of the measurement signal to the intelligent gateway.

[0034] Among them, the intelligent gateway can be a server based on edge computing, equipped with various relay protection component applications, and can realize microservices based on various relay protection components. The intelligent distribution gateway can collect, process and transmit the data collected and uploaded by various sensors and metering devices in the power grid monitoring system, and can also upload the processed data to the Internet of Things platform to realize the cloud storage and application of power grid data.

[0035] Exemplarily, the measuring device can upload the measured power parameters of the output end of the inverter, the power parameters of the first input end, and the power parameter data of the measurement signal to the intelligent gateway, so that the intelligent gateway can perform calculations and processing based on the received power parameters, thereby monitoring the operation status of the power grid according to the data processing results.

[0036] The intelligent gateway is used to receive the power parameters of the output end of the inverter, the power parameters of the first input end, and the power parameters of the measurement signal sent by the measuring device, and determine the impedance interaction phase angle margin between the inverter and the distribution network according to the power parameters of the output end of the inverter, the power parameters of the first input end, and the power parameters of the measurement signal;

[0037] Among them, the phase margin generally refers to the phase margin, also known as the phase margin, which is a very important indicator in circuit design. It is mainly used to measure the stability of the negative feedback system and can be used to predict the overshoot of the step response of the closed-loop system. A control system with good performance should have a phase margin of about 45°.

[0038] Furthermore, the intelligent distribution gateway can receive the power parameters of the output end of the inverter, the power parameters of the first input end and the power parameters of the measurement signal sent by the measuring device, and can calculate the impedance interaction phase margin between the inverter and the distribution network through data processing functions, thereby measuring the stability of the power grid system.

[0039] The intelligent gateway is also used to determine a parameter adjustment strategy of the inverter according to the impedance interaction phase margin value, and send the parameter adjustment strategy to the inverter, where the parameter adjustment strategy is used to instruct the inverter to adjust the equivalent output impedance according to the parameter adjustment strategy.

[0040] Among them, the parameter adjustment strategy of the inverter can be a specific scheme with the function of adjusting the inverter parameters, through which the inverter parameters can be adjusted; the preset value can be an empirical value of the impedance interaction phase margin that is adaptively set to measure the operating status of the power grid. For example, the preset value can be 30°, which is not limited here.

[0041] Furthermore, if the phase margin calculated by the smart gateway does not exceed the preset value, it means that the stability margin of the power grid system is low and is prone to instability. The smart gateway can increase the phase margin by adjusting the inverter operating parameters until it exceeds the preset value, thereby ensuring the stability of the power grid operation.

[0042] In the above-mentioned power grid monitoring system, a measurement signal is injected into the output end of the inverter and the first input end of the distribution network by a measuring device to measure the power parameters of the output end of the inverter and the power parameters of the first input end; then, the measuring device sends the measured power parameters of the output end of the inverter, the power parameters of the first input end and the power parameters of the measurement signal to the intelligent gateway; the intelligent gateway then determines the impedance interaction phase angle margin between the inverter and the distribution network by receiving the power parameters of the output end of the inverter, the power parameters of the first input end and the power parameters of the measurement signal sent by the measuring device; finally, the intelligent gateway determines the parameter adjustment strategy of the inverter according to the impedance interaction phase angle margin, so that the impedance interaction phase angle margin exceeds the preset value, thereby ensuring the continuous and stable operation of the power grid. At the same time, since the processing of all inverter impedance measurement data and the calculation of phase angle margin are realized by the edge computing function of the intelligent gateway, no additional computing chip is required in the disturbance signal injection and measurement device, which can reduce the equipment cost.

[0043] In one embodiment, involving power parameters measured by a measuring device, the power parameters of the output end of the inverter include the power parameters before the measurement signal is injected into the output end of the inverter and the power parameters after the measurement signal is injected into the output end of the inverter; the power parameters of the first input end include the power parameters before the measurement signal is injected into the first input end and the power parameters after the measurement signal is injected into the first input end.

[0044] Among them, the power parameters of the output end of the inverter can be two voltage data or two current data of the output end of the inverter before and after the measurement signal is injected; the power parameters of the first input end can be two voltage data or two current data of the first input end before and after the measurement signal is injected.

[0045] In the above-mentioned power grid monitoring system, the measuring device can upload the power parameters of the inverter output terminal and the first input terminal of the distribution network before and after the measurement signal is injected, as well as the power parameters of the measurement signal, and calculate the impedance interaction phase margin between the inverter and the distribution network through the intelligent gateway, thereby providing a basis for judging the operation status of the power grid.

[0046] In one embodiment, the step of confirming the impedance interaction phase margin by the intelligent gateway involves: Figure 3 A flow chart of determining an impedance interaction phase angle margin for an intelligent gateway, wherein the impedance interaction phase angle margin between an inverter and a distribution network is determined according to power parameters at an output end of the inverter, power parameters at a first input end, and power parameters of a measurement signal, including:

[0047] S301 : Calculate the admittance of the inverter according to the power parameters before the output end of the inverter is injected with the measurement signal and the power parameters after the output end of the inverter is injected with the measurement signal.

[0048] Among them, the impedance interaction phase margin between the inverter and the distribution network can measure the stability of the power grid system after the inverter is connected to the grid.

[0049] Furthermore, in order to calculate the impedance interaction phase margin between the inverter and the distribution network, it is necessary to first calculate the inverter's admittance and the grid impedance. For the inverter, the measuring device can inject a measurement signal at the inverter output end, for example, the injected measurement signal is a voltage disturbance signal, and then measure the current value before and after the measurement signal is injected into the inverter output end. The intelligent gateway can calculate the equivalent output impedance of the inverter according to Ohm's theorem; the injected measurement signal can also be a current disturbance signal. At this time, the measuring device measures the voltage value before and after the measurement signal is injected into the inverter output end. Similarly, the intelligent gateway can also calculate the equivalent output impedance of the inverter according to Ohm's theorem, which is not limited here. The reciprocal of the inverter impedance is the inverter admittance.

[0050] S302: Calculate the impedance of the first input terminal according to the power parameters before the measurement signal is injected into the first input terminal and the power parameters after the measurement signal is injected into the first input terminal.

[0051] The method for calculating the impedance of the first input terminal of the distribution network may be the same as the method for calculating the impedance of the inverter in step S301, and will not be described in detail here.

[0052] S303: Calculate the impedance interaction phase margin between the inverter and the distribution network according to the admittance of the inverter and the impedance of the first input terminal.

[0053] It should be noted that the impedance interaction phase margin between two circuit elements is related to the impedance of the two circuit elements. Therefore, in step S303, the impedance interaction phase margin between the inverter and the power distribution network can be calculated according to the admittance of the inverter and the impedance of the first input terminal.

[0054] Exemplarily, the intelligent gateway may calculate the impedance interaction phase margin between the inverter and the first input terminal of the distribution network according to the admittance of the inverter and the impedance of the first input terminal.

[0055] In the above-mentioned power grid monitoring system, the intelligent gateway calculates the inverter admittance and the impedance of the first input terminal of the distribution network through the above-mentioned power parameters uploaded by the measuring device, and then calculates the phase margin of the impedance interaction between the inverter and the first input terminal of the distribution network, thereby measuring the stability of the power grid operation under the current state. At the same time, since the processing of all inverter impedance measurement data and the calculation of phase margin are realized by the edge computing function of the intelligent gateway, no additional computing chip is required in the measuring device, thereby reducing the equipment cost.

[0056] In one embodiment, the specific steps of calculating the impedance interaction phase margin according to the inverter admittance and the impedance of the first input terminal of the power distribution network are as follows: Figure 4 As shown, the impedance interaction phase margin between the inverter and the distribution network is calculated according to the admittance of the inverter and the impedance of the first input terminal, including:

[0057] S401, calculating a loop gain between the inverter and the first input terminal of the distribution network according to the admittance of the inverter and the impedance of the first input terminal;

[0058] Assuming that the admittance of the k-th inverter is Yk, and the corresponding impedance of the first input end of the distribution network is Zk, the loop gain between the inverter and the impedance of the first input end of the distribution network is Lk=YkZk.

[0059] Furthermore, the intelligent gateway can calculate the loop gain between the inverter and the first input terminal according to the admittance of the inverter and the impedance of the first input terminal of the distribution network.

[0060] S402: Determine a target frequency according to an intersection point between a Nyquist curve of a loop gain and a unit circle, and determine an impedance interaction phase margin according to the target frequency.

[0061] Among them, Figure 5 As shown, assuming the target frequency is fPM, the target frequency is the intersection frequency of the Nyquist curve of the loop gain Lk and the unit circle. The calculation expression of the interaction phase margin PMk between the kth photovoltaic inverter and the grid impedance is as follows:

[0062]

[0063] Wherein, arctan represents the inverse tangent function, |ImLk| and |ReLk| represent the absolute values ​​of the imaginary and real parts of the loop gain Lk at the frequency fPM, respectively. The unit of the phase margin PMk calculated according to formula (1) is radian (expressed in rad), and the unit of the phase margin PMk can be obtained by multiplying it by 180 / π (expressed in degrees).

[0064] Furthermore, the intelligent gateway can determine the target frequency according to the intersection of the Nyquist curve of the loop gain and the unit circle, and then determine the impedance interaction phase margin according to the target frequency.

[0065] In the above-mentioned power grid monitoring system, the intelligent gateway calculates the loop gain between the inverter and the distribution network based on the admittance of the inverter and the impedance of the first input terminal of the distribution network, and then confirms the target frequency through the intersection of the Nyquist curve of the above-mentioned loop gain and the unit circle, thereby obtaining the impedance interaction phase margin between the inverter and the distribution network, providing a data basis for judging the stability of the power grid.

[0066] In one embodiment, Figure 6 As shown in FIG. 1 , the specific steps involved in determining the parameter adjustment strategy through the impedance interaction phase margin include:

[0067] S601, determining whether the impedance interaction phase margin exceeds a preset value;

[0068] The preset value may be an empirical value of impedance interaction phase margin adaptively set to measure grid stability.

[0069] Furthermore, the phase margin of the inverter and distribution network impedance interaction calculated by the intelligent gateway can be compared with the preset value to determine the stability of the current grid operation.

[0070] S602: If the impedance interaction phase angle margin does not exceed a preset value, determine a parameter adjustment strategy to instruct the inverter to adjust the equivalent output impedance so that the impedance interaction phase angle margin meets the preset value.

[0071] Among them, if the impedance interaction phase margin between the inverter and the distribution network does not exceed the preset value, it means that the current grid operation stability is poor.

[0072] Furthermore, the intelligent gateway can issue control instructions to the corresponding inverter to adjust the equivalent output impedance of the corresponding inverter, thereby improving the impedance interaction phase margin and ensuring the stable operation of the power grid system.

[0073] In the above-mentioned power grid monitoring system, the intelligent gateway monitors the stability of the power grid operation by judging whether the phase angle margin of the impedance interaction between the inverter and the distribution network exceeds the preset value. When the phase angle margin of the impedance interaction between the inverter and the distribution network does not exceed the preset value, the intelligent gateway sends a control instruction to the corresponding inverter, thereby improving the stability margin of the inverter operation and ensuring the safe and stable operation of the power grid.

[0074] In one embodiment, the parameter adjustment strategy involving the inverter may include: adjusting the output power of the inverter, and / or adjusting the current inner loop PI parameter of the inverter, and / or adjusting the phase-locked loop PI parameter of the inverter.

[0075] For example, the inverter parameter adjustment strategy may be that the smart gateway sends instructions to the corresponding photovoltaic maximum power tracking module to reduce the inverter output power to 70% of the original, or the smart gateway sends instructions to appropriately adjust the corresponding photovoltaic inverter control parameters (such as reducing the inverter current inner loop pi parameter), which is not limited here.

[0076] Furthermore, the inverter adjustment strategy described above can achieve the purpose of improving the impedance interaction stability margin between the inverter and the distribution network.

[0077] In the above-mentioned power grid monitoring system, when the impedance interaction phase margin between the inverter and the distribution network is lower than a preset value, the intelligent gateway can send instructions to the inverter to reduce the inverter output power or reduce the current inner loop pi parameter, thereby improving the impedance interaction phase margin between the inverter and the distribution network and improving the stability of the power grid operation.

[0078] The embodiment of the present application also provides a whole process of monitoring the power grid according to the impedance interaction phase margin, such as Figure 7 As shown, the process includes the following steps:

[0079] S1. The measuring device injects the measuring signal and uploads the power parameter data on both sides of the inverter grid connection point.

[0080] S2. Calculate the inverter admittance and distribution network impedance.

[0081] S3. Calculate the impedance interaction phase margin between the inverter and the distribution network.

[0082] S4. Determine whether the impedance interaction phase margin between the inverter and the distribution network exceeds a preset value.

[0083] S5. If the impedance interaction phase margin between the inverter and the distribution network exceeds the preset value, wait for t time and then return to step S1.

[0084] Among them, if the phase angle margin of the inverter and the distribution network impedance interaction exceeds the preset value, it means that the current grid operation is stable and no regulation is required. t can be a preset time, which can be the monitoring cycle of the grid monitoring system when the distribution network is running stably, and is not limited here.

[0085] S6. If the phase angle margin of the impedance interaction between the inverter and the distribution network does not exceed the preset value, determine a parameter adjustment strategy to improve the phase angle margin of the impedance interaction between the inverter and the distribution network, and immediately return to step S1.

[0086] Among them, if the phase angle margin of the impedance interaction between the inverter and the distribution network does not exceed the preset value, it means that the stability of the current grid operation is poor and needs to be adjusted. After improving the phase angle margin of the impedance interaction between the inverter and the distribution network through the parameter adjustment strategy, immediately return to step S1 to detect whether the current grid operation state is stable.

[0087] In the monitoring process of the above-mentioned power grid system, when the impedance interaction phase angle margin between the inverter and the distribution network exceeds the preset value, the intelligent gateway controls the measuring device to inject the measurement signal into the output terminal and the first input terminal of the inverter, and monitors the impedance interaction margin for a new period, thereby realizing the periodic dynamic monitoring of the power grid operation. At the same time, when the impedance interaction phase angle margin between the inverter and the distribution network does not exceed the preset value, after the impedance interaction phase angle margin between the inverter and the distribution network is improved through the parameter adjustment strategy, it immediately returns to step S1 until the power grid system operates stably.

[0088] It should be understood that although Figure 3 , Figure 4 and Figure 6 The steps in the flowchart are shown in sequence as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. Moreover, Figure 3 , Figure 4 and Figure 6 At least part of the steps may include multiple steps or multiple stages. These steps or stages are not necessarily performed at the same time, but can be performed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed in turn or alternately with other steps or at least part of the steps or stages in other steps.

[0089] In another embodiment, Figure 8 As shown, a smart gateway is provided, which is applied to a power grid monitoring system. The power grid monitoring system includes a power generation source, a distribution network, an inverter, a measuring device and a smart gateway. The smart gateway includes a communication unit 10 and a processing unit 20, wherein:

[0090] The communication unit 10 is used to receive the power parameters of the output end of the inverter, the power parameters of the first input end of the distribution network, and the power parameters of the measurement signal sent by the measuring device; wherein the power parameters of the output end of the inverter are obtained after the measuring device injects the measurement signal into the output end of the inverter, the first input end is the input end of the distribution network corresponding to the power generation source, and the power parameters of the first input end are obtained after the measuring device injects the measurement signal into the first input end;

[0091] The processing unit 20 is used to determine the impedance interaction phase angle margin between the inverter and the power distribution network according to the power parameters of the output end of the inverter, the power parameters of the first input end and the power parameters of the measurement signal;

[0092] The processing unit 20 is further used to determine a parameter adjustment strategy of the inverter according to the impedance interaction phase margin;

[0093] The communication unit 10 is further used to send a parameter adjustment strategy to the inverter, where the parameter adjustment strategy is used to instruct the inverter to adjust the equivalent output impedance according to the parameter adjustment strategy.

[0094] In one embodiment, the power parameters of the output end of the inverter include the power parameters before the measurement signal is injected into the output end of the inverter and the power parameters after the measurement signal is injected into the output end of the inverter;

[0095] The power parameter of the first input terminal includes the power parameter before the measurement signal is injected into the first input terminal and the power parameter after the measurement signal is injected into the first input terminal.

[0096] In one embodiment, the processing unit 20 is specifically used to calculate the admittance of the inverter based on the power parameters before the measurement signal is injected into the output end of the inverter and the power parameters after the measurement signal is injected into the output end of the inverter; or, calculate the admittance of the inverter based on the change value of the power parameter after the measurement signal is injected into the output end of the inverter;

[0097] Calculating the impedance of the first input terminal according to the power parameter before the measurement signal is injected into the first input terminal and the power parameter after the measurement signal is injected into the first input terminal; or calculating the impedance of the first input terminal according to the change value of the power parameter after the measurement signal is injected into the first input terminal;

[0098] The impedance interaction phase margin between the inverter and the power distribution network is calculated according to the admittance of the inverter and the impedance of the first input terminal.

[0099] In one embodiment, the processing unit 20 is specifically configured to determine a loop gain between the inverter and the first input terminal according to the admittance of the inverter and the impedance of the first input terminal;

[0100] The target frequency is determined according to the intersection of the Nyquist curve of the loop gain and the unit circle, and the impedance interaction phase margin is determined according to the target frequency.

[0101] In one embodiment, the processing unit 20 is specifically used to determine whether the impedance interaction phase margin value exceeds a preset value;

[0102] If the impedance interaction phase margin value does not exceed the preset value, a parameter adjustment strategy is determined to instruct the inverter to adjust the equivalent output impedance.

[0103] In one embodiment, the parameter adjustment strategy includes: adjusting the output power of the inverter, and / or adjusting the current inner loop pi parameter of the inverter, and / or adjusting the phase-locked loop pi parameter of the inverter.

[0104] In one embodiment, the communication unit 10 is further configured to instruct the measuring device to inject a measurement signal into the output terminal and the first input terminal of the inverter after a preset time period if the impedance interaction phase margin exceeds a preset value.

[0105] Specifically, the intelligent gateway provided in the above embodiment can be applied to the above power grid operation monitoring system. Its implementation principle and technical effects are similar and will not be repeated here.

[0106] The above modules used in the intelligent gateway can be implemented in whole or in part by software, hardware and their combination. The above modules can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory in the computer device in the form of software, so that the processor can call and execute the operations corresponding to the above modules.

[0107] In one embodiment, a computer device is provided. The computer device may be a server, and its internal structure diagram may be as follows: Fig. 9 As shown. The computer device includes a processor, a memory, a network interface and a database connected through a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store positioning information data. The network interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a method for processing positioning information is implemented.

[0108] Those skilled in the art will understand that Fig. 9 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0109] In another embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and when the processor executes the computer program, the computer device is used to implement the following steps:

[0110] Receive power parameters of the output end of the inverter, power parameters of the first input end, and power parameters of the measurement signal sent by the measuring device, determine the impedance interaction phase margin between the inverter and the distribution network according to the power parameters of the output end of the inverter, the power parameters of the first input end, and the power parameters of the measurement signal; determine a parameter adjustment strategy of the inverter according to the impedance interaction phase margin value, send the parameter adjustment strategy to the inverter, and the parameter adjustment strategy is used to instruct the inverter to adjust the equivalent output impedance according to the parameter adjustment strategy.

[0111] In another embodiment, a computer readable storage medium is provided, on which a computer program is stored, and when the computer program is executed by a processor, the following steps are implemented:

[0112] Receive power parameters of the output end of the inverter, power parameters of the first input end, and power parameters of the measurement signal sent by the measuring device, determine the impedance interaction phase margin between the inverter and the distribution network according to the power parameters of the output end of the inverter, the power parameters of the first input end, and the power parameters of the measurement signal; determine a parameter adjustment strategy of the inverter according to the impedance interaction phase margin value, send the parameter adjustment strategy to the inverter, and the parameter adjustment strategy is used to instruct the inverter to adjust the equivalent output impedance according to the parameter adjustment strategy.

[0113] The computer-readable storage medium provided in this embodiment has similar implementation principles and technical effects to those of the above method embodiments, and will not be described in detail here.

[0114] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory or optical memory, etc. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0115] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0116] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A power grid monitoring system, characterized in that: The power grid monitoring system includes a power generation device, a distribution network, an inverter, a measuring device and an intelligent gateway; The measuring device is used to inject a measurement signal into the output end of the inverter and the first input end of the power distribution network to measure the power parameters of the output end of the inverter and the power parameters of the first input end; The first input terminal is an input terminal of the distribution network corresponding to the power generation device; the measurement signal includes a voltage disturbance signal or a current disturbance signal, and the power parameter includes current or voltage; The measuring device is further used to send the power parameters of the output end of the inverter, the power parameters of the first input end, and the power parameters of the measurement signal to the intelligent gateway; The intelligent gateway is used to receive the power parameters of the output end of the inverter, the power parameters of the first input end, and the power parameters of the measurement signal sent by the measuring device, and determine the impedance interaction phase angle margin between the inverter and the distribution network according to the power parameters of the output end of the inverter, the power parameters of the first input end, and the power parameters of the measurement signal; The intelligent gateway is also used to determine a parameter adjustment strategy of the inverter according to the impedance interaction phase margin, and send the parameter adjustment strategy to the inverter, where the parameter adjustment strategy is used to instruct the inverter to adjust the equivalent output impedance according to the parameter adjustment strategy.

2. The system according to claim 1, characterized in that The power parameters of the output end of the inverter include the power parameters before the output end of the inverter is injected with the measurement signal and the power parameters after the output end of the inverter is injected with the measurement signal; The power parameter of the first input terminal includes the power parameter before the measurement signal is injected into the first input terminal and the power parameter after the measurement signal is injected into the first input terminal.

3. The system according to claim 2, characterized in that The intelligent gateway is specifically used to calculate the admittance of the inverter according to the power parameter of the measurement signal, the power parameter before the output end of the inverter is injected with the measurement signal, and the power parameter after the output end of the inverter is injected with the measurement signal; Calculating the impedance of the first input terminal according to the power parameter of the measurement signal, the power parameter of the first input terminal before the measurement signal is injected into the first input terminal, and the power parameter of the first input terminal after the measurement signal is injected into the first input terminal; An impedance interaction phase margin between the inverter and the power distribution network is calculated according to the admittance of the inverter and the impedance of the first input terminal.

4. The system according to claim 3, characterized in that The intelligent gateway is specifically used to determine the loop gain between the inverter and the first input end according to the admittance of the inverter and the impedance of the first input end; A target frequency is determined according to an intersection point between the Nyquist curve of the loop gain and a unit circle, and the impedance interaction phase margin is determined according to the target frequency.

5. The system according to claim 1, characterized in that The intelligent gateway is specifically used to determine whether the impedance interaction phase margin value exceeds a preset value; If the impedance interaction phase angle margin value does not exceed the preset value, it is determined that the parameter adjustment strategy instructs the inverter to adjust the equivalent output impedance so that the impedance interaction phase angle margin value exceeds the preset value.

6. The system according to claim 5, characterized in that The parameter adjustment strategy includes: adjusting the output power of the inverter, and / or adjusting the current inner loop PI parameter of the inverter, and / or adjusting the phase-locked loop PI parameter of the inverter.

7. The system according to claim 5, characterized in that The intelligent gateway is also used to instruct the measuring device to inject the measurement signal into the output end and the first input end of the inverter after a preset time period if the impedance interaction phase margin exceeds the preset value.

8. An intelligent gateway, characterized in that: The smart gateway is applied to a power grid monitoring system, which includes a power generation device, a distribution network, an inverter, a measuring device and the smart gateway, and the smart gateway includes: A communication unit, used for receiving the power parameters of the output end of the inverter, the power parameters of the first input end of the distribution network and the power parameters of the measurement signal sent by the measuring device; wherein the power parameters of the output end of the inverter are obtained after the measuring device injects the measurement signal into the output end of the inverter, the first input end is the input end of the distribution network corresponding to the power generation source, and the power parameters of the first input end are obtained after the measuring device injects the measurement signal into the first input end; the measurement signal includes a voltage disturbance signal or a current disturbance signal, and the power parameters include current or voltage; a processing unit, configured to determine an impedance interaction phase margin between the inverter and the power distribution network according to a power parameter of an output terminal of the inverter, a power parameter of the first input terminal, and a power parameter of the measurement signal; The processing unit is further used to determine a parameter adjustment strategy of the inverter according to the impedance interaction phase angle margin; The communication unit is further used to send the parameter adjustment strategy to the inverter, where the parameter adjustment strategy is used to instruct the inverter to adjust the equivalent output impedance according to the parameter adjustment strategy.

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

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