Microgrid system control method, terminal and storage medium

Abstract

The invention provides a micro-grid system control method, a terminal and a storage medium. The method comprises the following steps: acquiring the energy storage electric quantity of the energy storage subsystem; if the energy storage electric quantity of the energy storage subsystem is smaller than a first preset electric quantity threshold value, the photovoltaic power generation subsystem is controlled to start working; if the energy storage electric quantity of the energy storage subsystem is smaller than a second preset electric quantity threshold value and the output power is larger than first preset power, the diesel power generation subsystem is controlled to start working based on the output power of the energy storage subsystem; wherein the second preset electric quantity threshold value is smaller than the first preset electric quantity threshold value. According to the scheme, under the condition that the electric quantity of the energy storage subsystem is moderate, the photovoltaic power generation subsystem is preferentially adopted to supply power, and when the electric quantity of the energy storage subsystem is insufficient, the diesel generator is started to work, so that economical and green operation of the microgrid system is realized.

Description

Technical Field

[0001] The present invention relates to the field of microgrid technology, and in particular to a control method, a terminal and a storage medium for a microgrid system. Background Art

[0002] When the microgrid is in operation, diesel generators, micro gas turbines, fuel cells and other controllable micro power sources with stable output power and large capacity are often used to adjust the system to maintain the stability of system voltage and frequency.

[0003] In recent years, the requirements for energy security, environmental protection and climate change have become increasingly severe and prominent. Therefore, new energy power generation technologies such as wind and light have made great progress. At the same time, with the increase in energy types, how to achieve stable and economic operation of microgrid systems has become a major problem that needs to be solved urgently. Summary of the invention

[0004] The embodiments of the present invention provide a control method, a terminal and a storage medium for a microgrid system to solve the problem of stable and economical operation of a multi-source microgrid system.

[0005] In a first aspect, an embodiment of the present invention provides a control method for a microgrid system, wherein the microgrid system includes an energy storage subsystem, a diesel generator subsystem, and a photovoltaic generator subsystem; the energy storage subsystem, the diesel generator subsystem, and the photovoltaic generator subsystem are all connected to an AC bus of the microgrid system; the AC bus is also used to connect a power grid and a load;

[0006] The method comprises:

[0007] Obtaining the energy storage capacity of the energy storage subsystem;

[0008] If the energy storage capacity of the energy storage subsystem is less than a first preset capacity threshold, controlling the photovoltaic power generation subsystem to start working;

[0009] If the energy storage capacity of the energy storage subsystem is less than the second preset capacity threshold and the output power is greater than the first preset power, the diesel generator subsystem is controlled to start working based on the output power of the energy storage subsystem; wherein the second preset capacity threshold is less than the first preset capacity threshold.

[0010] In a second aspect, an embodiment of the present invention provides a terminal, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the steps of the method for controlling a microgrid system as described in any possible implementation of the first aspect above are implemented.

[0011] In a third aspect, an embodiment of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the control method of the microgrid system as described in any possible implementation method of the first aspect above are implemented.

[0012] The embodiment of the present invention provides a control method, terminal and storage medium of a microgrid system, wherein the method first obtains the energy storage capacity of the energy storage subsystem; if the energy storage capacity of the energy storage subsystem is less than a first preset capacity threshold, the photovoltaic power generation subsystem is controlled to start working; if the energy storage capacity of the energy storage subsystem is less than a second preset capacity threshold, and the output power is greater than the first preset power, the diesel power generation subsystem is controlled to start working based on the output power of the energy storage subsystem; wherein the second preset capacity threshold is less than the first preset capacity threshold. In the above embodiment, when the energy storage subsystem has an appropriate amount of capacity, the photovoltaic power generation subsystem is preferentially used for power supply, and when the energy storage subsystem is insufficiently charged, the diesel generator is started to work, thereby realizing the economical and green operation of the microgrid system. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0014] Figure 1 is a schematic structural diagram of a microgrid system provided by an embodiment of the present invention;

[0015] Figure 2 is a flow chart of an implementation method of a microgrid system control method provided by an embodiment of the present invention;

[0016] Figure 3 is a schematic diagram of the structure of a control device for a microgrid system provided by an embodiment of the present invention;

[0017] Figure 4 is a schematic diagram of a terminal provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0018] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present invention.

[0019] In order to make the purpose, technical solutions and advantages of the present invention more clear, specific embodiments will be described below in conjunction with the accompanying drawings.

[0020] Figure 1 Schematic diagram of the structure of the microgrid system provided by the embodiment of the present invention. Figure 1 As shown, the microgrid system includes an energy storage subsystem, a diesel generator subsystem and a photovoltaic generator subsystem; the energy storage subsystem, the diesel generator subsystem and the photovoltaic generator subsystem are all connected to the AC bus of the microgrid system; the AC bus is also used to connect the power grid and the load.

[0021] Specifically, the photovoltaic power generation subsystem includes a photovoltaic power generation group and a photovoltaic inverter, the energy storage subsystem includes an energy storage converter PCS and multiple energy storage modules, each energy storage module includes an energy storage battery and a DC conversion circuit DCDC, and each energy storage battery is connected to one end of the corresponding DC conversion circuit DCDC, the other end of each DC conversion circuit DCDC is connected to the DC end of the energy storage converter PCS, and the AC end of the energy storage converter PCS is connected to the AC bus of the microgrid system; the DC end of the photovoltaic inverter is connected to the output end of the photovoltaic power generation group, and the AC end of the photovoltaic inverter is connected to the AC bus of the microgrid system.

[0022] In this embodiment, the microgrid system further includes a monitoring host, a controller of the energy storage subsystem, a controller of the photovoltaic subsystem, and a controller of the diesel subsystem. The monitoring host is respectively connected to the controller of the energy storage subsystem, the controller of the photovoltaic subsystem, and the controller of the diesel subsystem.

[0023] See also Figure 2 , which shows a flow chart of the implementation of the control method of the microgrid system provided by an embodiment of the present invention, and is described in detail as follows:

[0024] S101: Acquire the energy storage capacity of the energy storage subsystem.

[0025] Specifically, the execution subject of this embodiment is a monitoring host, which is used to obtain the energy storage power uploaded by the energy storage subsystem. The energy storage power can be obtained by adding the power data of each energy storage module in the energy storage subsystem. The energy storage power can include SOC (State of Charge), voltage or power, etc. The SOC value is used as the specific data of the energy storage power for subsequent explanation.

[0026] S102: If the energy storage capacity of the energy storage subsystem is less than a first preset capacity threshold, the photovoltaic power generation subsystem is controlled to start operation.

[0027] In this embodiment, when the microgrid system is operating off-grid, if the monitoring host detects that the energy storage capacity is less than the first preset capacity threshold, it means that the current storage capacity of the energy storage subsystem is not too high, and the photovoltaic power generation subsystem can generate electricity to ensure the power supply of the load. At the same time, the cost of photovoltaic power generation is low, and it is a green energy with less pollutants. Therefore, when the power demand of the microgrid system is small, the photovoltaic power generation subsystem can be used for power supply.

[0028] In this embodiment, if the energy storage capacity of the energy storage subsystem is greater than the first preset capacity threshold, when the load has a power demand, only the energy storage subsystem is used for power supply, and the photovoltaic power generation subsystem and the diesel power generation subsystem do not work.

[0029] S103: If the energy storage capacity of the energy storage subsystem is less than a second preset capacity threshold and the output power is greater than a first preset power, the diesel generator subsystem is controlled to start working based on the output power of the energy storage subsystem; wherein the second preset capacity threshold is less than the first preset capacity threshold.

[0030] In this embodiment, when the output power of the energy storage subsystem is a negative value, the energy storage subsystem is in a charging state, and when the output power of the energy storage subsystem is a positive value, the energy storage subsystem is in a discharging state, and the first preset power is a negative value. When the microgrid system is off-grid, if the energy storage capacity of the energy storage subsystem is less than the second preset capacity threshold, it means that the energy storage capacity of the energy storage subsystem is small at this time. If the output power of the energy storage subsystem is not greater than the first preset power at this time, it means that the energy storage subsystem is discharging at this time, and the discharge power is large enough to power the load, so the diesel generator subsystem can be disabled. If the output power of the energy storage subsystem is greater than the first preset power at this time, it means that the energy storage subsystem is in a charging state or the discharge power is very small. At this time, relying solely on the photovoltaic power generation subsystem to generate electricity cannot meet the power demand of the load and the energy storage subsystem. Therefore, the diesel generator subsystem can be started based on the output power of the energy storage subsystem to ensure the power demand of the load and the energy storage subsystem.

[0031] Specifically, the first preset power threshold may be 60% to 80%, and the second preset power threshold may be 10% to 30%.

[0032] From the above embodiments, it can be seen that in this embodiment, when the power of the energy storage system is appropriate, the photovoltaic power generation system is preferentially used for power supply, and when the power of the energy storage system is insufficient, the diesel generator is started to work, thereby realizing the economical and green operation of the microgrid system.

[0033] In a possible implementation, the specific implementation process of S103 includes:

[0034] If the energy storage capacity of the energy storage subsystem is less than the second preset capacity threshold, and the output power is greater than the first preset power, it is determined whether the output power is less than the second preset power; and the second preset power is greater than the first preset power;

[0035] If the output power is less than the second preset power, controlling the diesel generator subsystem to start working at a third preset power;

[0036] If the output power is not less than the second preset power, the diesel generator subsystem is controlled to start working at a fourth preset power; the fourth preset power is the sum of the output power of the energy storage subsystem and the third preset power.

[0037] In this embodiment, the second preset power can be zero. When the output power is less than the second preset power, it means that the energy storage subsystem is in a discharging state. At this time, the diesel generator subsystem can only provide the power required by the load. When the output power is not less than the second preset power, it means that the energy storage subsystem is in a charging state. At this time, power needs to be supplied to the energy storage subsystem and the load. Therefore, the power generation power of the diesel generator subsystem is the sum of the load power and the output power of the energy storage subsystem.

[0038] The above scheme can ensure the stable operation of the microgrid system in an off-grid state.

[0039] In a possible implementation manner, after S102, the method provided in this embodiment further includes:

[0040] When the microgrid system is in an off-grid state, the expected power of the photovoltaic power generation subsystem at the next moment is determined according to the expected power of the photovoltaic power generation subsystem at the current moment, the output power of the energy storage subsystem and the power generation power of the diesel power generation subsystem.

[0041] In a possible implementation, the above process further includes:

[0042] S201: Determine whether the expected power of the photovoltaic power generation subsystem at the current moment is less than a first power threshold;

[0043] S202: If the expected power of the photovoltaic power generation subsystem at the current moment is not less than the first power threshold, determining whether the power generation power of the diesel power generation subsystem is less than the diesel power threshold;

[0044] S203: If the power generation power of the diesel generator subsystem is less than the diesel generator power threshold, determining whether the output power of the energy storage subsystem is less than zero;

[0045] S204: If the output power of the energy storage subsystem is less than zero, determining the expected power of the photovoltaic power generation subsystem at the next moment according to the expected power at the current moment and the output power of the energy storage subsystem.

[0046] Exemplarily, when the power generation capacity of the diesel generator subsystem is small and the energy storage subsystem is in a charging state, it is necessary to determine the power generation capacity required by the photovoltaic generator subsystem based on the charging power of the energy storage subsystem, the expected power of the photovoltaic generator subsystem at the current moment, the power generation capacity of the diesel generator subsystem and the load power, wherein the diesel generator power threshold may be 10KW.

[0047] Specifically, in the microgrid system, based on the formula P spi +P 柴 +P pcs =P f Control photovoltaic power generation, where P spi,t represents the power generation power of the photovoltaic power generation system, P 柴 Indicates the power generation of the diesel generator system, P f Indicates load power, P pcs Represents the output power of the energy storage subsystem; when the energy storage system is in the charging state, P pcs <0.

[0048] In a possible implementation, the specific implementation process of S204 includes:

[0049] According to the formula P spi,t+1 =P m +(P spi,t -|P pcs |), determining the expected power of the photovoltaic power generation system at the next moment;

[0050] Among them, P spi,t+1 represents the expected power of the photovoltaic power generation system at the next moment, P m Represents the expected power of energy storage; P spi,t represents the expected power of the photovoltaic power generation system at the current moment, P pcs Represents the output power of the energy storage subsystem.

[0051] In this embodiment, based on the above formula, the output power of the energy storage subsystem can be stabilized near the expected energy storage power and meet the load power demand by adjusting the power generation power of the photovoltaic power generation subsystem.

[0052] In a possible implementation manner, the specific implementation process of S102 further includes:

[0053] If the power generation power of the diesel power generation subsystem is not less than the diesel power threshold, or the output power of the energy storage subsystem is not less than zero, then determine whether the expected power of the photovoltaic power generation subsystem at the current moment is less than a second power threshold; the second power threshold is greater than the first power threshold;

[0054] If the expected power of the photovoltaic power generation subsystem at the current moment is less than the second power threshold, determining the expected power of the photovoltaic power generation subsystem at the next moment according to the load power of the microgrid system;

[0055] If the expected power of the photovoltaic power generation subsystem at the current moment is not less than the first power threshold, it is determined that the expected power of the photovoltaic power generation subsystem at the next moment is the first power threshold.

[0056] In this embodiment, the first power threshold may be 10-40 kW, and the second power threshold may be an upper limit value of photovoltaic power generation power.

[0057] In a possible implementation, the specific implementation process of determining the expected power of the photovoltaic power generation subsystem at the next moment according to the load power of the microgrid system includes:

[0058] The expected energy storage power is added to the load power to obtain the expected power of the photovoltaic power generation subsystem at the next moment.

[0059] In one possible implementation, the microgrid system has three working states: grid-connected state, off-grid state, and on-grid and off-grid switching state. When the external power grid is normal, the microgrid system works in the grid-connected state. When the external power grid fails and stops operating, the microgrid system operates off-grid, providing AC power with stable and reliable voltage and frequency for the load of the microgrid system. The monitoring host detects the state of the external power grid to achieve a smooth transition between the grid-connected working state and the off-grid working state.

[0060] In this embodiment, when the microgrid system is connected to the grid, the output power of the microgrid system grid side is set. Through system adjustment, the output power of the microgrid side is set to the set power. Specifically, when the microgrid is connected to the grid, the monitoring system is started to monitor and record the tie line power on the output side of the microgrid, and the monitoring system observes whether the output side of the microgrid system meets the set power.

[0061] In this embodiment, the microgrid system also has a peak shaving and valley filling function, which requires setting the number of charging and discharging time periods, the start time of each charging and discharging period, and the charging and discharging power. In this embodiment, the charging and discharging time periods for peak shaving and valley filling and the charging and discharging power values ​​corresponding to each charging and discharging time period can be set to perform charging and discharging control. Specifically, the monitoring system can also monitor the tie line power in each time period when the microgrid system is connected to the grid, and observe whether the tie line power in each time period meets the set time period distribution.

[0062] In this embodiment, when the microgrid system is connected to the grid and the external grid fails or fluctuates abnormally, the microgrid system immediately detects the abnormality and automatically switches to an off-grid state. The power output of each micro-power source in the system is automatically coordinated to achieve a balance between the active output and reactive output and consumption in the microgrid system. Specifically, the controller of the energy storage subsystem controls the grid-side air switch to disconnect to simulate the power failure of the external grid. After the microgrid monitoring host detects the power failure of the external grid, it switches from the grid-connected operation state to the off-grid operation state. During the switching process, the microgrid system is controlled to have no overvoltage or overcurrent, and the switching time is no more than 30ms.

[0063] In this embodiment, when the microgrid system is in off-grid operation, when the external grid fault is eliminated, the microgrid system needs to automatically switch to the grid-connected operation state after the synchronization is completed. Specifically, the controller of the energy storage subsystem closes the grid-side air switch; then detects the voltage and phase on both sides of the grid-connected circuit breaker. When the synchronization is completed, the voltage amplitude deviation on both sides of the grid-connected circuit breaker is less than 5%, and the phase deviation is less than 5°, then the synchronization is qualified; after the synchronization is qualified, the controller controls the grid-side air switch to close, and the microgrid system switches the operation mode to the grid-connected operation mode.

[0064] In this embodiment, when an abnormality occurs in the power grid, the microgrid system can play a role in voltage regulation. When the grid voltage is less than the set normal value, the grid outputs reactive power to support the grid. When the grid voltage is greater than the set normal value, the microgrid system absorbs reactive power to reduce the grid voltage. Specifically, when the microgrid system is working in a grid-connected state, a first voltage reference point is set, and when the grid voltage is less than the set voltage reference point, observe whether the microgrid system outputs reactive power to support the grid; and a second voltage reference point is set, and when the grid voltage is greater than the set normal value, observe whether the microgrid system absorbs reactive power to reduce the grid voltage.

[0065] When the grid is abnormal, the microgrid system can play a role in frequency regulation. When the grid frequency is lower than the set normal value, the microgrid outputs active power to increase the grid frequency. When the grid frequency is higher than the set normal value, the microgrid system charges the battery through rectification to reduce the grid's active power and reduce the grid frequency.

[0066] In this embodiment, when the load of the microgrid system is greater than the power that the microgrid system can provide, the microgrid system has the function of low frequency load shedding. When the grid frequency is lower than the set normal value, the microgrid system will first cut off the secondary load to ensure the power consumption of the main load.

[0067] In this embodiment, when the microgrid system is off-grid, the main power supply of the microgrid system is kept operating in the economic operation range, the charging and discharging times and the charging and discharging power of the energy storage subsystem are limited, and the switching strategy of each distributed power source and load is determined according to the system operation status.

[0068] In this embodiment, the microgrid system includes multiple energy storage subsystems, multiple photovoltaic power generation subsystems, and diesel power generation subsystems. Under normal circumstances, when there is an energy storage subsystem with an energy storage capacity less than a first preset capacity threshold, in order to avoid over-discharge of the energy storage subsystem, the monitoring host will control the photovoltaic power generation subsystem to start working. When there is an energy storage subsystem with an energy storage capacity less than a second preset capacity threshold, and the output power of the energy storage subsystem is greater than the first preset power, the diesel power generation subsystem is controlled to start working based on the output power of the energy storage subsystem. However, when the energy storage capacity among multiple energy storage subsystems is unbalanced, this method will cause other power sources to enter too early or exit untimely. Therefore, in order to avoid system instability caused by inaccurate control between power sources in the microgrid system, this embodiment performs a pulse control on the energy storage subsystem in the microgrid system. The process specifically includes:

[0069] Obtaining the power data and initial charging and discharging parameter given values ​​of all energy storage subsystems in the microgrid system;

[0070] Based on the power data of all energy storage subsystems, calculate the total energy storage power value of the microgrid system;

[0071] For any energy storage subsystem, the initial charge and discharge parameter given values ​​of the energy storage subsystem are corrected according to the power data of the energy storage subsystem and the total energy storage power value to obtain the final charge and discharge parameter given values ​​of the energy storage subsystem, and the charge and discharge of the energy storage subsystem is controlled based on the final charge and discharge parameter given values.

[0072] In a possible implementation, based on the power data of the energy storage subsystem and the total value of the energy storage power, the initial charge and discharge parameter given values ​​of the energy storage subsystem are corrected to obtain the final charge and discharge parameter given values ​​of the energy storage subsystem, including:

[0073] Calculate the average value of energy storage power according to the total value of energy storage power and the number of energy storage subsystems in the microgrid system;

[0074] If the power data of the first energy storage subsystem is greater than the average value of the energy storage power, the initial charge and discharge parameter given value of the first energy storage subsystem is increased to obtain the final charge and discharge parameter given value of the first energy storage subsystem; the first energy storage subsystem is any energy storage subsystem in the microgrid system;

[0075] If the power data of the first energy storage subsystem is less than the average value of the energy storage power, the initial charge and discharge parameter given value of the first energy storage subsystem is adjusted down to obtain the final charge and discharge parameter given value of the current online battery unit.

[0076] In a possible implementation, if the power data of the first energy storage subsystem is greater than the average value of the energy storage power, increasing the initial charge and discharge parameter given value of the first energy storage subsystem to obtain the final charge and discharge parameter given value of the first energy storage subsystem, including:

[0077] If the power data of the first energy storage subsystem is greater than the average power value of the energy storage, subtract the average power value of the energy storage from the power data of the first energy storage subsystem to obtain a power difference;

[0078] Determine a first parameter compensation value according to the power difference and the working state of the energy storage system; the power difference is positively correlated with the first parameter compensation value; the working state includes a charging state and a discharging state;

[0079] The initial charge and discharge parameter given value of the first energy storage subsystem is added to the first parameter compensation value to obtain the final charge and discharge parameter given value of the first energy storage subsystem.

[0080] In a possible implementation, if the power data of the first energy storage subsystem is greater than the average power of the energy storage, increasing the given value of the initial charge and discharge parameter of the first energy storage subsystem includes:

[0081] If the power data of the first energy storage subsystem is greater than the average value of the energy storage power, the initial charge and discharge parameter given value of the first energy storage subsystem is increased according to the unit adjustment step.

[0082] In a possible implementation, based on the power data of the energy storage subsystem and the total value of the energy storage power, the initial charge and discharge parameter given values ​​of the energy storage subsystem are corrected to obtain the final charge and discharge parameter given values ​​of the energy storage subsystem, including:

[0083] Calculate the average value of energy storage power according to the total value of energy storage power and the number of energy storage subsystems in the microgrid system;

[0084] If the energy storage system is in a charging state, the data of the amount to be charged is obtained according to the power data of the first energy storage subsystem, and the average value of the amount to be charged is obtained according to the average value of the energy storage power; the first energy storage subsystem is any energy storage subsystem in the microgrid system;

[0085] Dividing the data of the amount to be charged by the average value of the amount to be charged to obtain a first ratio, and multiplying the initial charge and discharge parameter given value by the first ratio to obtain a final charge and discharge parameter given value of the first energy storage subsystem;

[0086] If the energy storage system is in a discharging state, the power data of the first energy storage subsystem is divided by the average value of the energy storage power to obtain a second ratio;

[0087] The initial charge and discharge parameter given value is multiplied by the second ratio to obtain a final charge and discharge parameter given value of the first energy storage subsystem.

[0088] It can be seen from the above embodiments that the method provided in this embodiment can not only ensure the stable operation of the microgrid system, but also give priority to photovoltaic power generation when the microgrid system has insufficient energy storage, and use the diesel power generation subsystem for emergency response to ensure load power supply. At the same time, when the energy storage subsystem is charging and discharging, the power in multiple microgrid subsystems is balanced in real time, avoiding the problem of untimely startup and exit of the photovoltaic power generation subsystem and the diesel power generation subsystem due to unbalanced power between microgrid subsystems, thereby further ensuring the stable operation of the microgrid system.

[0089] It should be understood that the order of execution of the steps in the above embodiment does not necessarily mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

[0090] The following is an embodiment of the device of the present invention. For details not described in detail therein, reference may be made to the corresponding method embodiment described above.

[0091] Figure 3 The structure diagram of the control device of the microgrid system provided by the embodiment of the present invention is shown. For the convenience of description, only the part related to the embodiment of the present invention is shown, which is described in detail as follows:

[0092] like Figure 3 As shown, the control device 100 of the microgrid system includes:

[0093] The energy storage power acquisition module 110 is used to acquire the energy storage power of the energy storage subsystem;

[0094] The photovoltaic starting module 120 is used to control the photovoltaic power generation subsystem to start working if the energy storage capacity of the energy storage subsystem is less than a first preset capacity threshold;

[0095] The diesel generator starting module 130 is used to control the diesel generator subsystem to start working based on the output power of the energy storage subsystem if the energy storage capacity of the energy storage subsystem is less than a second preset capacity threshold and the output power is greater than a first preset power; wherein the second preset capacity threshold is less than the first preset capacity threshold.

[0096] In a possible implementation, the diesel engine starting module 130 includes:

[0097] If the energy storage capacity of the energy storage subsystem is less than the second preset capacity threshold, and the output power is greater than the first preset power, it is determined whether the output power is less than the second preset power; and the second preset power is greater than the first preset power;

[0098] If the output power is less than the second preset power, controlling the diesel generator subsystem to start working at a third preset power;

[0099] If the output power is not less than the second preset power, the diesel generator subsystem is controlled to start working at a fourth preset power; the fourth preset power is the sum of the output power of the energy storage subsystem and the third preset power.

[0100] In a possible implementation, the control device 100 of the microgrid system further includes a photovoltaic working module for:

[0101] When the microgrid system is in an off-grid state, the expected power of the photovoltaic power generation subsystem at the next moment is determined according to the expected power of the photovoltaic power generation subsystem at the current moment, the output power of the energy storage subsystem and the power generation power of the diesel power generation subsystem.

[0102] In one possible implementation, the photovoltaic working module further includes:

[0103] An expected power judgment unit, used to judge whether the expected power of the photovoltaic power generation subsystem at the current moment is less than a first power threshold;

[0104] a diesel power determination unit, configured to determine whether the power generation power of the diesel power generation subsystem is less than a diesel power threshold if the expected power of the photovoltaic power generation subsystem at the current moment is not less than a first power threshold;

[0105] an energy storage power judgment unit, configured to judge whether the output power of the energy storage subsystem is less than zero if the power generation power of the diesel generator subsystem is less than the diesel generator power threshold;

[0106] The expected power determination unit is used to determine the expected power of the photovoltaic power generation subsystem at the next moment according to the expected power at the current moment and the output power of the energy storage subsystem if the output power of the energy storage subsystem is less than zero.

[0107] In a possible implementation manner, the expected power determination unit includes:

[0108] According to the formula P spi,t+1 =P m +(P spi,t -|P pcs |), determining the expected power of the photovoltaic power generation system at the next moment;

[0109] Among them, P spi,t+1 represents the expected power of the photovoltaic power generation system at the next moment, P m Represents the expected power of energy storage; P spi,trepresents the expected power of the photovoltaic power generation system at the current moment, P pcs Represents the output power of the energy storage subsystem.

[0110] In a possible implementation, the photovoltaic working module further includes:

[0111] If the power generation power of the diesel power generation subsystem is not less than the diesel power threshold, or the output power of the energy storage subsystem is not less than zero, then determine whether the expected power of the photovoltaic power generation subsystem at the current moment is less than a second power threshold; the second power threshold is greater than the first power threshold;

[0112] If the expected power of the photovoltaic power generation subsystem at the current moment is less than the second power threshold, determining the expected power of the photovoltaic power generation subsystem at the next moment according to the load power of the microgrid system;

[0113] If the expected power of the photovoltaic power generation subsystem at the current moment is not less than the first power threshold, it is determined that the expected power of the photovoltaic power generation subsystem at the next moment is the first power threshold.

[0114] In a possible implementation, the photovoltaic working module further includes:

[0115] The expected energy storage power is added to the load power to obtain the expected power of the photovoltaic power generation subsystem at the next moment.

[0116] Figure 4 is a schematic diagram of a terminal provided by an embodiment of the present invention. Figure 4 As shown, the terminal 4 of this embodiment includes: a processor 40 and a memory 41. The memory 41 is used to store a computer program 42, and the processor 40 is used to call and run the computer program 42 stored in the memory 41 to execute the steps in the above-mentioned control method embodiments of each microgrid system, such as Figure 2 Alternatively, the processor 40 is used to call and run the computer program 42 stored in the memory 41 to implement the functions of each module / unit in the above-mentioned device embodiments, for example Figure 3 The functions of the modules 110 to 130 are shown.

[0117] Exemplarily, the computer program 42 may be divided into one or more modules / units, which are stored in the memory 41 and executed by the processor 40 to implement the present invention. The one or more modules / units may be a series of computer program instruction segments capable of implementing specific functions, which are used to describe the execution process of the computer program 42 in the terminal 4. For example, the computer program 42 may be divided into Figure 3 Modules 110 to 130 are shown.

[0118] The terminal 4 may be a computing device such as a desktop computer, a notebook, a PDA, or a cloud server. The terminal 4 may include, but is not limited to, a processor 40 and a memory 41. Those skilled in the art will appreciate that Figure 4 It is only an example of terminal 4 and does not constitute a limitation on terminal 4. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the terminal may also include input and output devices, network access devices, buses, etc.

[0119] The processor 40 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0120] The memory 41 may be an internal storage unit of the terminal 4, such as a hard disk or memory of the terminal 4. The memory 41 may also be an external storage device of the terminal 4, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the terminal 4. Further, the memory 41 may also include both an internal storage unit and an external storage device of the terminal 4. The memory 41 is used to store the computer program and other programs and data required by the terminal. The memory 41 may also be used to temporarily store data that has been output or is to be output.

[0121] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0122] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0123] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0124] In the embodiments provided by the present invention, it should be understood that the disclosed devices / terminals and methods can be implemented in other ways. For example, the device / terminal embodiments described above are only schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0125] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0126] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0127] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by the processor, the steps of the control method embodiments of each microgrid system can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electric carrier signals and telecommunication signals.

[0128] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A control method for a microgrid system, characterized in that: The microgrid system includes an energy storage subsystem, a diesel generator subsystem and a photovoltaic generator subsystem; the energy storage subsystem, the diesel generator subsystem and the photovoltaic generator subsystem are all connected to the AC bus of the microgrid system; the AC bus is also used to connect the power grid and the load; The method comprises: Obtaining the energy storage capacity of the energy storage subsystem; If the energy storage capacity of the energy storage subsystem is less than a first preset capacity threshold, controlling the photovoltaic power generation subsystem to start working; If the energy storage capacity of the energy storage subsystem is less than the second preset capacity threshold and the output power is greater than the first preset power, the diesel generator subsystem is controlled to start working based on the output power of the energy storage subsystem; wherein the second preset capacity threshold is less than the first preset capacity threshold.

2. The control method of the microgrid system according to claim 1, characterized in that: If the energy storage capacity of the energy storage subsystem is less than the second preset capacity threshold and the output power is greater than the first preset power, the diesel generator subsystem is controlled to start working based on the output power of the energy storage subsystem, including: If the energy storage capacity of the energy storage subsystem is less than the second preset capacity threshold, and the output power is greater than the first preset power, it is determined whether the output power is less than the second preset power; and the second preset power is greater than the first preset power; If the output power is less than the second preset power, controlling the diesel generator subsystem to start working at a third preset power; If the output power is not less than the second preset power, the diesel generator subsystem is controlled to start working at a fourth preset power; the fourth preset power is the sum of the output power of the energy storage subsystem and the third preset power.

3. The control method of the microgrid system according to claim 1, characterized in that: After controlling the photovoltaic power generation subsystem to start working, the method further includes: When the microgrid system is in an off-grid state, the expected power of the photovoltaic power generation subsystem at the next moment is determined according to the expected power of the photovoltaic power generation subsystem at the current moment, the output power of the energy storage subsystem and the power generation power of the diesel power generation subsystem.

4. The control method of the microgrid system according to claim 3, characterized in that: The method of determining the expected power of the photovoltaic power generation subsystem at the next moment according to the expected power of the photovoltaic power generation subsystem at the current moment, the output power of the energy storage subsystem and the power generation power of the diesel power generation subsystem comprises: Determining whether the expected power of the photovoltaic power generation subsystem at the current moment is less than a first power threshold; If the expected power of the photovoltaic power generation subsystem at the current moment is not less than the first power threshold, then determining whether the power generation power of the diesel power generation subsystem is less than the diesel power threshold; If the power generation power of the diesel generator subsystem is less than the diesel generator power threshold, determining whether the output power of the energy storage subsystem is less than zero; If the output power of the energy storage subsystem is less than zero, the expected power of the photovoltaic power generation subsystem at the next moment is determined according to the expected power at the current moment and the output power of the energy storage subsystem.

5. The control method of the microgrid system according to claim 4, characterized in that: The step of determining the expected power of the photovoltaic power generation subsystem at the next moment according to the expected power at the current moment and the output power of the energy storage subsystem comprises: According to the formula P spi,t+1 =P m +(P spi,t -|P pcs |), determining the expected power of the photovoltaic power generation system at the next moment; Among them, P spi,t+1 represents the expected power of the photovoltaic power generation system at the next moment, P m Represents the expected power of energy storage; P spi,t represents the expected power of the photovoltaic power generation system at the current moment, P pcs Represents the output power of the energy storage subsystem.

6. The control method of the microgrid system according to claim 4, characterized in that: The step of determining the expected power of the photovoltaic power generation subsystem at the next moment according to the expected power of the photovoltaic power generation subsystem at the current moment, the output power of the energy storage subsystem and the power generation power of the diesel power generation subsystem further comprises: If the power generation power of the diesel power generation subsystem is not less than the diesel power threshold, or the output power of the energy storage subsystem is not less than zero, then determine whether the expected power of the photovoltaic power generation subsystem at the current moment is less than a second power threshold; the second power threshold is greater than the first power threshold; If the expected power of the photovoltaic power generation subsystem at the current moment is less than the second power threshold, determining the expected power of the photovoltaic power generation subsystem at the next moment according to the load power of the microgrid system; If the expected power of the photovoltaic power generation subsystem at the current moment is not less than the first power threshold, it is determined that the expected power of the photovoltaic power generation subsystem at the next moment is the first power threshold.

7. The control method of the microgrid system according to claim 6, characterized in that: The step of determining the expected power of the photovoltaic power generation subsystem at the next moment according to the load power of the microgrid system includes: The expected energy storage power is added to the load power to obtain the expected power of the photovoltaic power generation subsystem at the next moment.

8. The control method of the microgrid system according to claim 6, characterized in that: The microgrid system includes a plurality of energy storage subsystems, and the method further includes: Based on the power data of all energy storage subsystems, calculate the total energy storage power value of the microgrid system; For any energy storage subsystem, the initial charge and discharge parameter given values ​​of the energy storage subsystem are corrected according to the power data of the energy storage subsystem and the total energy storage power value to obtain the final charge and discharge parameter given values ​​of the energy storage subsystem, and the charge and discharge of the energy storage subsystem is controlled based on the final charge and discharge parameter given values.

9. A terminal, characterized in that: It comprises a processor and a memory, wherein the memory is used to store a computer program, and the processor is used to call and run the computer program stored in the memory to execute the control method of the microgrid system according to any one of claims 1 to 8.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the control method of the microgrid system as described in any one of claims 1 to 8 are implemented.

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