A microgrid controller with reactive power compensation control function

Abstract

The present invention relates to a microgrid controller with a reactive power compensation control function applied to the power supply field. By collecting voltage and current data at the grid connection point to obtain the power factor, it determines whether reactive power compensation is required, and through the dual-channel communication line between the monitoring processor and the PCS energy storage converter, it sends the reactive power regulation value to the PCS energy storage converter to achieve reactive power compensation, and continuously collects data at the grid connection point to verify the regulation effect. When there is no response to the regulation within the specified time, by operating such as starting the test load, switching the line, and detecting the heating condition of the line, it determines whether there are faults such as monitoring processor failure, PCS energy storage converter failure, or communication line failure, giving the staff a preliminary and effective direction for fault repair, realizing targeted priority troubleshooting, effectively improving the fault handling efficiency, and enabling the present application to quickly resume normal operation.

Description

Technical Field

[0001] The present invention relates to a microgrid controller, and particularly to a microgrid controller with a reactive power compensation control function applied to the power supply field. Background Art

[0002] The problem of reactive power factor has been a relatively prominent problem encountered by distributed energy storage power stations in recent years, especially industrial and commercial energy storage power stations. Since such power stations are usually connected to the internal low-voltage or medium-voltage power grids of enterprises, there are a large number of electrical equipment connected to the grid, especially inductive loads such as motors. The existing reactive power problems in the grid generally achieve the purpose of automatic compensation through reactive power compensation equipment (such as SVG equipment) installed in the grid. However, there are many incorrect commands and actions, resulting in an increase in the proportion of reactive power in the grid.

[0003] To solve the above problems, the specification of Chinese Patent CN118054428B discloses a reactive power compensation method and terminal for an energy storage system. By detecting the actual active power factor on the grid side and the actual reactive power factor on the grid side, and controlling the PCS (energy storage converter) on the user side to compensate for reactive power according to the actual operating state on the grid side, the reactive power generated by the energy storage system has an impact on the grid side that meets the power consumption requirements, and the energy storage power station operates efficiently and stably, achieving the maximum economic benefit.

[0004] Another example is that the specification of Chinese Patent CN119518824A discloses a reactive power compensation control method for a distribution substation based on an energy storage PCS converter. A multi-objective optimization model is constructed, and the objective function of the model can comprehensively consider reactive power compensation, active power optimization, voltage stability, and energy efficiency improvement, effectively improving the performance and reliability of the reactive power compensation control method for the distribution substation based on the energy storage PCS converter, and realizing a more efficient and stable power grid operation.

[0005] Although the prior art realizes reactive power compensation for the power grid through a PCS energy storage converter, it fails to verify the adjustment result in a timely manner, nor does it judge the possible fault conditions in the case of no response to the adjustment, resulting in relatively large operation defects in the entire reactive power compensation process. Summary of the Invention

[0006] Aiming at the above prior art, the technical problem to be solved by the present invention is that in the process of reactive power compensation for the power grid through a PCS energy storage converter, the adjustment result is not verified in a timely manner, nor is the fault condition judged in the case of no response to the adjustment, resulting in relatively large defects.

[0007] To solve the above problems, the present invention provides a microgrid controller with a reactive power compensation control function, which includes an energy storage module, a photovoltaic power generation module, and multiple operating loads connected to the power grid, and also includes a monitoring processor, a PCS energy storage converter, and a test load connected to the power grid;

[0008] The monitoring processor includes a data acquisition module, a power judgment module, a reactive power regulation module, and a target database. The data acquisition module includes a voltage monitoring unit and a current monitoring unit for monitoring the grid connection point. The power judgment module obtains the power factor based on the acquired voltage and current data and determines whether reactive power compensation is required. The reactive power regulation module sends the reactive power regulation value to be compensated to the PCS energy storage converter.

[0009] The power judgment module is connected with a timing module and a fault prediction module. The fault prediction module performs fault prediction on the monitoring processor, the PCS energy storage converter, and the dual-channel communication line between them when the PCS energy storage converter does not respond normally.

[0010] The dual-channel communication line includes a switching switch arranged between the monitoring processor and the PCS energy storage converter. A main transmission line is connected between the switching switch and the monitoring processor. A transmission branch line and a standby branch line are connected between the switching switch and the PCS energy storage converter. A temperature sensor is provided at the connection point of the main transmission line and the monitoring processor.

[0011] A microgrid controller with reactive power compensation control function, and its usage method includes the following steps:

[0012] S1. Reactive power compensation: The monitoring processor collects the voltage and current data of the grid connection point, and then obtains the active power, reactive power, and actual power factor. According to the preset target power factor, it is judged whether the actual power factor meets the standard. When it meets the standard, no adjustment operation is performed. When it does not meet the standard, the difference between the actual power factor and the target power factor is used as the reactive power regulation value, and the reactive power regulation value is sent to the PCS energy storage converter. The PCS energy storage converter compensates the reactive power of the microgrid system according to the reactive power regulation value.

[0013] S2. Response verification: Continuously collect the data of the grid connection point to verify the adjustment effect. When the measured actual power factor meets the standard after a specified time, it indicates that the adjustment is successful. On the contrary, when the measured actual power factor still does not meet the standard after a specified time, it indicates that there is no response to the adjustment. At this time, a fault prediction operation is performed.

[0014] S3. Fault prediction:

[0015] S3-1. Start the test load and collect the voltage and current data of the grid connection point again. When the voltage and current data do not change as expected, a fault prompt for the monitoring processor is given. When the two data change as expected, go to step S3-2;

[0016] S3-2. Simultaneously perform the following multiple operations: First, continuously send the reactive power regulation value to the PCS energy storage converter. Second, continue to collect the data of the grid connection point and obtain the actual power factor. Third, change the transmission line between the monitoring processor and the PCS energy storage converter through a switching switch, from using the transmission branch communication to using the standby branch communication;

[0017] S3-3. When the measured actual power factor reaches the standard after a specified time, it indicates that the regulation is successful, and a transmission branch fault prompt is given. When the measured actual power factor still does not reach the standard after a specified time, at this time, obtain the temperature data of the temperature sensor within the previous T time period from this moment;

[0018] S3-4. When any of the following situations exists, it indicates that there is no data transmission on the communication line: the temperature data is in a continuous decreasing state or the temperature data remains within the room temperature range, and a communication line fault prompt is given. On the contrary, when the temperature data does not meet any of the above situations, a PCS energy storage converter fault prompt is given.

[0019] As a further supplement to this application, the fault prediction module is connected to a test database, and the test database stores the voltage data range and current data range of the grid connection point during the operation of the test load.

[0020] As a further supplement to this application, in step S3-1, the method for judging whether the voltage and current data change corresponding to the expectation includes: when the collected voltage data and current data are respectively within the voltage data range and the current data range, it is determined that the corresponding expected change has occurred. When any of the following situations exists, it is determined that the voltage and current data have not changed corresponding to the expectation: the collected voltage data is not within the voltage data range or the current data is not within the current data range.

[0021] As a further supplement to this application, the temperature sensor includes a heat insulation cover fixedly connected to both the monitoring processor and the transmission main line and sleeved outside the connection position of the two. A temperature sensor is fixedly connected to the inner wall of the heat insulation cover, and an air pipe communicated with it is fixedly connected to the outer end of the heat insulation cover. An electric control valve is fixedly installed inside the air pipe.

[0022] As another improvement to this application, the fault prediction module is connected to a measurement accuracy module. Both the temperature sensor and the electric control valve are connected to the measurement accuracy module. The measurement accuracy module is connected to a temperature trend library, and the temperature trend library records the temperature drop trend data inside the heat insulation cover when the electric control valve is opened. There are multiple pieces of the drop trend data, and their starting temperatures are different and the time lengths are the same.

[0023] As a further supplement to another improvement to this application, its usage method further includes a measurement accuracy operation, and the measurement accuracy operation includes the following steps:

[0024] The electric control valve is periodically activated by the measurement accuracy module to keep it in an open state, and then the monitoring data of the temperature sensor in a subsequent period of time is obtained in real time. When the change condition of the monitoring data matches any of the temperature drop trend data, it indicates that the accuracy of the temperature sensor is good; otherwise, it is determined that the accuracy of the temperature sensor is abnormal.

[0025] As another improvement of the present application, a heat collection box A is provided at the connection between the transmission branch line and the switching switch, and a heat collection box B is provided at the connection between the standby branch line and the switching switch. Gas pipelines with air pumps are fixedly connected between both the heat collection box A and the heat collection box B and the temperature sensor monitor.

[0026] As a supplement to another improvement of the present application, the heat collection box A and the heat collection box B have the same structure, and both include a mesh cover. Inside the mesh cover, there is a sealed flexible bag body. One end of a hose is fixedly connected to the sealed flexible bag body, and the other end of the hose is fixedly connected and communicated with the corresponding gas pipeline.

[0027] In summary, the present application obtains the power factor by collecting the voltage and current data of the grid connection point, determines whether reactive power compensation is required, and sends the reactive power regulation value to the PCS energy storage converter through the dual-channel communication line between the monitoring processor and the PCS energy storage converter to achieve reactive power compensation, and continuously collects the grid connection point data to verify the regulation effect. When there is no response to the regulation within the specified time, by operating such as starting the test load, switching the line, and detecting the heating condition of the line, it is determined whether there are faults such as monitoring processor failure, PCS energy storage converter failure, or communication line failure, giving the staff a preliminary and effective fault repair direction, achieving targeted priority troubleshooting, effectively improving the fault handling efficiency, and enabling the present application to quickly resume normal operation;

[0028] The heating condition of the communication line is monitored by the temperature sensor monitor, and a measurement accuracy module is set to periodically test the sensitivity of the temperature sensor in the temperature sensor monitor, further improving the detection accuracy of the heating condition of the communication line, thereby improving the fault prediction accuracy;

[0029] Combined with the heat collection box A provided on the transmission branch line and the temperature sensor monitor provided on the transmission main line, the heating condition of the transmission branch line during the communication process is detected, realizing early warning of the transmission branch line fault, enabling the staff to activate the switching switch in advance and switch to the standby branch line, reducing the impact on the reactive power compensation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is the system block diagram of the microgrid controller of the first and second embodiments of the present application;

[0031] Figure 2 It is the system block diagram of the monitoring processor of the first and second embodiments of the present application;

[0032] Figure 3 It is a schematic structural diagram of the dual-channel communication line between the monitoring processor and the PCS energy storage converter in the first and second implementation manners of this application;

[0033] Figure 4 It is a flowchart of the usage method in the first and second implementation manners of this application;

[0034] Figure 5 It is a schematic structural diagram of the temperature sensor monitor in the first and second implementation manners of this application;

[0035] Figure 6 It is a schematic structural diagram during the accurate measurement operation in the second implementation manner of this application;

[0036] Figure 7 It is a schematic structural diagram of the dual-channel communication line between the monitoring processor and the PCS energy storage converter in the third implementation manner of this application;

[0037] Figure 8 It is a schematic connection structure diagram between the temperature sensor monitor and the heat collection box A in the third implementation manner of this application;

[0038] Figure 9 It is a schematic structural diagram during the heat detection process of the transmission branch line in the third implementation manner of this application.

[0039] Explanation of the reference numerals in the figure:

[0040] 1 heat insulation cover, 2 temperature sensor, 3 air pipe, 4 electric control valve, 5 mesh cover, 6 sealed flexible bag body, 7 hose. Specific implementation manner

[0041] The following will make a detailed description of the three implementation manners of this application with reference to the accompanying drawings.

[0042] The first implementation manner:

[0043] The present invention provides a microgrid controller with a reactive power compensation control function. Please refer to Figure 1 , which includes an energy storage module, a photovoltaic power generation module, and multiple operating loads connected to the power grid. The operating loads are multiple normally operating electrical devices. This application also includes a monitoring processor, a PCS energy storage converter, and a test load connected to the power grid. The test load can be a general electrical device, such as a lighting device, and normally the test load is in a non-operating state.

[0044] Please refer to Figure 2, the monitoring processor includes a data acquisition module, a power judgment module, a reactive power regulation module, and a target database. The data acquisition module includes a voltage monitoring unit and a current monitoring unit for monitoring the grid connection point. The two realize the data acquisition of voltage and current through corresponding sensors (voltage sensor and current sensor). The power judgment module obtains the power factor based on the acquired voltage and current data and judges whether reactive power compensation is required. The reactive power regulation module issues the reactive power regulation value to be compensated to the PCS energy storage converter (for the specific reactive power compensation method, see step S1 below);

[0045] The power judgment module is connected to a timing module and a fault prediction module. The fault prediction module performs fault prediction on the monitoring processor, the PCS energy storage converter, and the dual-channel communication line between the two when the PCS energy storage converter does not respond normally (for the specific prediction method, see step S3 below);

[0046] Please refer to Figure 3 , the dual-channel communication line includes a switching switch arranged between the monitoring processor and the PCS energy storage converter. A transmission main line is connected between the switching switch and the monitoring processor. A transmission branch line and a standby branch line are connected between the switching switch and the PCS energy storage converter. A temperature sensor is provided at the connection between the transmission main line and the monitoring processor.

[0047] Please refer to Figure 4 , a microgrid controller with reactive power compensation control function, and its usage method includes the following steps:

[0048] S1. Reactive power compensation: Collect the voltage and current data of the grid connection point through the monitoring processor, and then obtain the active power, reactive power, and actual power factor. According to the preset target power factor, judge whether the actual power factor meets the standard. When it meets the standard, no adjustment operation is performed. When it does not meet the standard, the difference between the actual power factor and the target power factor is used as the reactive power regulation value, and the reactive power regulation value is issued to the PCS energy storage converter. The PCS energy storage converter compensates the reactive power of the microgrid system according to the reactive power regulation value;

[0049] Specifically, the instantaneous reactive power theory (p-q theory) of the existing technology can be used to obtain the active power P and the reactive power Q, and then the power factor PE is obtained through the two, where: , the preset target power factor is generally 0.95 - 0.98. When the obtained actual power factor is within this range, it is considered to meet the standard. When the actual power factor is lower than this range, reactive power compensation is required;

[0050] S2. Response verification: Continuously collect the data of the grid connection point, verify the adjustment effect. When the measured actual power factor meets the standard after the specified time, it indicates that the adjustment is successful. On the contrary, when the measured actual power factor still does not meet the standard after the specified time, it indicates that there is no response to the adjustment. At this time, a fault prediction operation is performed;

[0051] S3. Fault prediction:

[0052] S3-1. Start the test load, and collect the voltage and current data of the grid connection point again. When the voltage and current data do not change as expected, a fault prompt for the monitoring processor is given. When the two data change as expected, it is initially judged that the monitoring processor has no fault. At this time, step S3-2 is performed;

[0053] S3-2. At the same time, perform the following multiple operations: First, continuously send the reactive power adjustment value to the PCS energy storage converter; second, continue to collect the data of the grid connection point to obtain the actual power factor; third, combine Figure 3 As shown, replace the transmission line between the monitoring processor and the PCS energy storage converter through the changeover switch, and change from using the transmission branch communication to using the standby branch communication;

[0054] S3-3. When the measured actual power factor meets the standard after the specified time, it indicates that the adjustment is successful, and a fault prompt for the transmission branch is given. When the measured actual power factor still does not meet the standard after the specified time, at this time, obtain the temperature data of the temperature sensor within the previous T time period from this moment;

[0055] The standby branch not only provides another data communication guarantee between the monitoring processor and the PCS energy storage converter, but also can effectively verify whether there is a fault in the transmission branch. When it is not judged that there is a fault in the transmission branch, combined with the temperature monitoring situation of the transmission main line joint by the temperature sensor, judge whether there is a fault in the transmission main line. Specifically: Under normal circumstances, when the cable is transmitting data, due to the existence of current inside, heat will inevitably be generated. Therefore, under normal circumstances, the temperature data of the temperature sensor will be in a slow rising state (without considering the heat exchange between the temperature sensor and the outside) or maintained in a temperature range higher than the room temperature (considering the heat loss of the temperature sensor);

[0056] S3-4. When any of the following situations occurs, it indicates that there is no data transmission on the communication line: the temperature data is in a continuous decreasing state or the temperature data is maintained within the room temperature range. This situation indicates that there is no current passing through the communication line, and its heat gradually dissipates and is close to the room temperature. Therefore, a fault prompt for the communication line is given. On the contrary, when the temperature data does not meet any of the above situations (it may be in a rising state, a floating state, or a stable state higher than the room temperature, etc.), it indicates that there is still current passing through the communication line and it has the function of data transmission. At this time, a fault prompt for the PCS energy storage converter is given;

[0057] Through the fault prediction process of the above-mentioned step S3, when the reactive power compensation fails to respond normally, a preliminary and effective fault repair direction is given to the staff, facilitating targeted priority troubleshooting, effectively improving the fault handling efficiency, and enabling the present application to quickly resume normal operation.

[0058] Regarding the process of step S3-1: Combining Figure 2 As shown, the fault prediction module is connected to a test database, and the test database stores the voltage data range and current data range of the grid connection point during the operation of the test load. In step S3-1, the method for determining whether the voltage and current data have corresponding expected changes includes: when the collected voltage data and current data are respectively within the voltage data range and current data range, it is determined that the corresponding expected changes have occurred; when any of the following situations exists, it is determined that the voltage and current data have not undergone corresponding expected changes: the collected voltage data is not within the voltage data range or the current data is not within the current data range.

[0059] When the test load changes from the initial non-operating state to the normal operating state, it will cause corresponding changes in the voltage and current at the grid connection point. Therefore, after starting the test load, the voltage and current data of the grid connection point are collected again and compared with the pre-stored voltage data range and current data range, so as to determine whether the voltage sensor and current sensor for collecting voltage and current data are faulty. If the sensors are not faulty (i.e., the monitoring processor is not faulty), the collected voltage and current data are generally within the voltage data range and current data range. If the voltage data is not within the voltage data range or the collected current data is not within the current data range, it indicates that the voltage sensor or current sensor is faulty (i.e., the monitoring processor is faulty).

[0060] Combining Figure 3 and Figure 5 As shown, the temperature sensor monitor includes a heat insulation cover 1 fixedly connected to both the monitoring processor and the transmission main line and sleeved outside the connection position of the two. A temperature sensor 2 is fixedly connected to the inner wall of the heat insulation cover 1. Since there is a contact resistance at the joint of the communication line and its heat generation situation is relatively large compared with other positions of the line, the temperature sensor monitor is set at the connection position of the monitoring processor and the transmission main line. The heat accumulates inside the heat insulation cover 1. The temperature sensor 2 is connected to the fault prediction module, and its installation position can be closest to the joint at the maximum extent to improve the temperature monitoring accuracy, and the monitored temperature data is transmitted to the fault prediction module to facilitate the prediction process of step S3-4.

[0061] The second implementation method:

[0062] Based on the first implementation method, the following content is added in this implementation method: Please refer to Figure 5, the outer end of the heat shield 1 is fixedly connected to an air pipe 3 communicating with it, and an electric control valve 4 is fixedly installed inside the air pipe 3. Combining Figure 2 As shown, the fault prediction module is connected to a measurement accuracy module. The temperature sensor 2 and the electric control valve 4 are both connected to the measurement accuracy module. The measurement accuracy module is connected to a temperature trend library, and the temperature trend library records the temperature drop trend data inside the heat shield 1 when the electric control valve 4 is opened. There are multiple pieces of drop trend data, and their starting temperatures are different and the time lengths are the same.

[0063] Through the above settings, the usage method of the microgrid controller with reactive power compensation control function of the present invention further includes a measurement accuracy operation. The measurement accuracy operation includes the following steps: Please refer to Figure 6 , regularly start the electric control valve 4 through the measurement accuracy module to make it in an open state, and then obtain the monitoring data of the temperature sensor 2 in a subsequent period of time in real time. When the change condition of the monitoring data matches any temperature drop trend data, it indicates that the accuracy of the temperature sensor 2 is good. Otherwise, it is determined that the accuracy of the temperature sensor 2 is abnormal.

[0064] When the electric control valve 4 is opened, the heat inside the heat shield 1 can flow to the outside through the air pipe 3 and the electric control valve 4 for heat exchange with the outside, so that the temperature inside the heat shield 1 gradually approaches the outside temperature. Therefore, under normal circumstances, the temperature data monitored by the temperature sensor 2 will gradually decrease. From this, it can be judged whether the sensitivity (i.e., accuracy) of the temperature sensor 2 is normal. Moreover, the operation of releasing the heat in the heat shield 1 can also play a role in cooling and protecting the connection of the transmission main line, so that the accumulated heat is not easy to affect the normal use of the transmission main line, thus playing a role with double effects; the purpose of setting multiple drop trend data is: since the temperature situation inside the heat shield 1 when the electric control valve 4 is opened in the actual situation is uncertain, in order to improve the accuracy of the measurement accuracy operation, the temperature inside the heat shield 1 is preheated to different degrees, and then the electric control valve 4 is opened, and the temperature drop trend in the heat shield 1 within a certain period of time is recorded, so as to obtain multiple drop trend data with different starting temperatures and the same time length, which is convenient for later comparison and analysis with the actual situation.

[0065] The 3rd implementation mode:

[0066] On the basis of the 2nd implementation mode, the following content is added to this implementation mode: Please refer to Figure 7 , a heat collection box A is provided at the connection between the transmission branch line and the switching switch, and a heat collection box B is provided at the connection between the standby branch line and the switching switch. Gas pipelines with air pumps are fixedly connected between both the heat collection box A and the heat collection box B and the temperature sensor. Please refer to Figure 8, The heat collection boxes A and B have the same structure, and both include a mesh cover 5. Inside the mesh cover 5, there is a sealed flexible bag 6. The sealed flexible bag 6 is initially in an unfolded state to collect the heat at the connection. One end of a hose 7 is fixedly connected to the sealed flexible bag 6, and the other end of the hose 7 is fixedly connected and communicated with the corresponding gas pipeline. The end of the gas pipeline connected to the heat insulation cover 1 has its pipe orifice facing the sensing end of the temperature sensor 2. The flexible feature of the hose 7 can adapt to the shape change of the sealed flexible bag 6.

[0067] In this embodiment, the heat collection boxes A and B are respectively used to collect the temperature at the joints of the transmission branch line and the standby branch line. The temperature accumulates inside the sealed flexible bag 6. During use, the temperature sensing monitor, the heat collection boxes A and B can be used to monitor the heat generation of the transmission branch line and the standby branch line. The specific steps are as follows:

[0068] Step 1: Under normal circumstances, since the transmission branch line is used for data transmission and the standby branch line is not used, there is no need to detect the standby branch line, and the heat generation of the transmission branch line can be detected. The detection process is as follows: After completing the accurate measurement operation in the second embodiment and determining that the accuracy of the temperature sensor 2 is normal, please refer to Figure 9 , Keep the electric control valve 4 in the open state, start the air pump, extract the hot air in the sealed flexible bag 6 and input it into the heat insulation cover 1, and spray it towards the sensing end of the temperature sensor 2 (since the electric control valve 4 is still in the open state, the air pressure in the heat insulation cover 1 can remain balanced). Under normal circumstances, the temperature data monitored by the temperature sensor 2 will increase significantly (since the temperature in the heat insulation cover 1 has approached the outside temperature after the accurate measurement operation), indicating that the transmission branch line is in a normal communication state and there is current passing through. On the contrary, when the monitored data of the temperature sensor 2 does not change significantly, it indicates that the gas extracted from the sealed flexible bag 6 does not have obvious heat, which can to a certain extent indicate that there may be no current passing through the transmission branch line and there is a fault. Thus, an early warning of the transmission branch line fault can be given in advance, enabling the staff to start the changeover switch in advance, switch to the standby branch line, reduce the impact on the reactive power compensation process, and timely conduct on-site maintenance of the transmission branch line;

[0069] Step 2: After it is determined in Step 1 that the transmission branch line is in a normal communication state, wait for a period of time first to enable the heat insulation cover 1 to continue to exchange heat with the outside through the air pipe 3 and the electric control valve 4, and discharge the heat ejected from the gas pipeline. After the temperature data of the temperature sensor 2 drops to a stable state, start the air pump again and make it reverse, extract the gas in the heat insulation cover 1 that approaches the outside temperature, and transport it to the sealed flexible bag 6 to make the sealed flexible bag 6 return to its initial unfolded state, facilitating the next detection process, and the temperature inside it is lower compared to before the detection process, which is convenient for cooling protection of the joint;

[0070] Step 3: Turn off the air pump and the electric control valve 4 so that the heat insulation cover 1 and the sealed flexible bag body 6 continue to collect heat.

[0071] In addition, after the operation of starting the changeover switch in advance in Step 1 and switching to the standby branch line, the same heat generation detection process as in Step 1 can be used to detect the heat generation condition of the standby branch line, so as to achieve early warning of whether the standby branch line is faulty.

[0072] Combined with the current actual requirements, the above-mentioned implementation manner adopted in this application, the protection scope is not limited thereto. Within the scope of knowledge possessed by those skilled in the art, various changes made without departing from the concept of this application still fall within the protection scope of the present invention.

Claims

1. A microgrid controller with reactive power compensation control function, comprising an energy storage module, a photovoltaic power generation module and a plurality of operating loads connected to the power grid, characterized in that: It also includes a monitoring processor, a PCS energy storage converter and a test load connected to the power grid; The monitoring processor includes a data acquisition module, a power judgment module, a reactive power regulation module and a target database. The data acquisition module includes a voltage monitoring unit and a current monitoring unit for monitoring the grid connection point. The power judgment module obtains the power factor based on the collected voltage and current data and judges whether reactive power compensation is required. The reactive power regulation module sends the reactive power regulation value to be compensated to the PCS energy storage converter; The power judgment module is connected with a timing module and a fault prediction module. The fault prediction module predicts faults for the monitoring processor, the PCS energy storage converter and the dual-channel communication line between them when the PCS energy storage converter does not respond normally; The dual-channel communication line includes a switch disposed between the monitoring processor and the PCS energy storage converter. A main transmission line is connected between the switch and the monitoring processor. A transmission branch line and a standby branch line are connected between the switch and the PCS energy storage converter. A temperature sensor is provided at the connection between the main transmission line and the monitoring processor; The fault prediction operation of the fault prediction module includes the following steps: Step a: Start the test load and collect the voltage and current data of the grid connection point. When the voltage and current data do not change as expected, a fault prompt for the monitoring processor is given. When the two data change as expected, go to step b; Step b: Perform the following multiple operations simultaneously: First, continuously send the reactive power regulation value to the PCS energy storage converter. Second, continue to collect the data of the grid connection point and obtain the actual power factor. Third, change the transmission line between the monitoring processor and the PCS energy storage converter through the switch, changing from using the transmission branch line for communication to using the standby branch line for communication; Step c: When the measured actual power factor meets the standard after a specified time, it indicates that the regulation is successful and a fault prompt for the transmission branch line is given. When the measured actual power factor still does not meet the standard after a specified time, at this time, obtain the temperature data of the temperature sensor in the previous T time period before this moment; Step d: When any of the following situations occurs, it indicates that there is no data transmission on the communication line: The temperature data is in a continuous decreasing state or the temperature data remains within the room temperature range, and a fault prompt for the communication line is given. Otherwise, when the temperature data does not meet any of the above situations, a fault prompt for the PCS energy storage converter is given.

2. The microgrid controller with a reactive power compensation control function according to claim 1, characterized in that: Its usage method includes the following steps: S1. Reactive power compensation: The monitoring processor collects the voltage and current data of the grid connection point, and then obtains the active power, reactive power and actual power factor. According to the preset target power factor, it is judged whether the actual power factor meets the standard. When it meets the standard, no adjustment operation is performed. When it does not meet the standard, the difference between the actual power factor and the target power factor is used as the reactive power regulation value, and the reactive power regulation value is sent to the PCS energy storage converter. The PCS energy storage converter compensates the reactive power of the microgrid system according to the reactive power regulation value; S2. Response verification: Continuously collect the grid connection point data and verify the regulation effect. When the measured actual power factor meets the standard after a specified time, it indicates that the regulation is successful. On the contrary, when the measured actual power factor still does not meet the standard after the specified time, it indicates that there is no response to the regulation. At this time, a fault prediction operation is performed.

3. A microgrid controller with a reactive power compensation control function according to claim 2, characterized in that: The fault prediction module is connected to a test database, and the test database stores the voltage data range and current data range at the grid connection point during the operation of the test load.

4. A microgrid controller with a reactive power compensation control function according to claim 3, characterized in that: In step a, the method for determining whether the voltage and current data change corresponding to the expectation includes: when the collected voltage data and current data are respectively within the voltage data range and the current data range, it is determined that the corresponding expected change has occurred. When any of the following situations exists, it is determined that the voltage and current data have not changed corresponding to the expectation: the collected voltage data is not within the voltage data range or the current data is not within the current data range.

5. A microgrid controller with a reactive power compensation control function according to claim 1, characterized in that: The temperature sensor includes a heat insulation cover (1) fixedly connected to both the monitoring processor and the main transmission line and sleeved outside the connection position of the two. A temperature sensor (2) is fixedly connected to the inner wall of the heat insulation cover (1). An air pipe (3) communicated with the heat insulation cover (1) is fixedly connected to the outer end of the heat insulation cover (1), and an electric control valve (4) is fixedly installed inside the air pipe (3).

6. The microgrid controller with a reactive power compensation control function according to claim 5, characterized in that: The fault prediction module is connected to an accuracy measurement module. Both the temperature sensor (2) and the electric control valve (4) are connected to the accuracy measurement module. The accuracy measurement module is connected to a temperature trend library, and the temperature trend library records the temperature drop trend data inside the heat insulation cover (1) when the electric control valve (4) is opened. There are multiple pieces of the drop trend data, and their starting temperatures are different and the time lengths are the same.

7. A microgrid controller with a reactive power compensation control function according to claim 6, characterized in that: Its usage method also includes an accuracy measurement operation, and the accuracy measurement operation includes the following steps: Regularly start the electric control valve (4) through the accuracy measurement module to make it in an open state, and then obtain the monitoring data of the temperature sensor (2) in a subsequent period of time in real time. When the change condition of the monitoring data matches any of the temperature drop trend data, it indicates that the accuracy of the temperature sensor (2) is good. On the contrary, it is determined that there is an abnormality in the accuracy of the temperature sensor (2).

8. A microgrid controller with a reactive power compensation control function according to claim 1, characterized in that: A heat collection box A is provided at the connection of the transmission branch line and the change-over switch, and a heat collection box B is provided at the connection of the standby branch line and the change-over switch. Gas pipelines with air pumps are fixedly connected between both the heat collection box A and the heat collection box B and the temperature sensor.

9. The microgrid controller with a reactive power compensation control function according to claim 8, characterized in that: The heat collection box A and the heat collection box B have the same structure, and both include a wire mesh cover (5). A sealed flexible bag body (6) is arranged inside the wire mesh cover (5). One end of a hose (7) is fixedly connected to the sealed flexible bag body (6), and the other end of the hose (7) is fixedly connected and communicated with the corresponding gas pipeline.

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