Optical storage diesel micro-grid system control method and device, electronic equipment and storage medium

Abstract

The invention relates to a control method and device for an optical storage diesel micro-grid system, electronic equipment and a storage medium, and the method comprises the steps: carrying out the descending arrangement of the rated capacity of an energy storage battery of each energy storage battery subsystem of an energy storage system in the optical storage diesel micro-grid system, and determining a target energy storage battery subsystem; determining the current photovoltaic power according to the current charge state of the target energy storage battery subsystem; and according to the current load power demand or the current charge state, determining a start-stop state of a diesel generator of the optical-storage-diesel-fuel micro-grid system so as to realize power balance control of the optical-storage-diesel-fuel micro-grid system. According to the invention, the fine management of the photovoltaic-stored-diesel micro-grid system is realized, the current photovoltaic power and the start and stop of the diesel generator are adjusted according to the charge state of the energy storage battery, the common auxiliary energy storage of the photovoltaic power generation system and the diesel generator is realized, the stability, power supply reliability and flexibility of the photovoltaic-stored-diesel micro-grid system are improved, and the service life of the photovoltaic-stored-diesel micro-grid system is prolonged.

Description

Background Art

[0002] With the rapid development of modern society, users have put forward higher requirements for the stability and sustainability of power supply. However, when facing the access of distributed energy and fluctuations in power demand, large power grids have problems such as insufficient scheduling flexibility and the need to improve power supply stability, which cannot fully meet the diversified needs of users.

[0003] The control strategy of the photovoltaic-storage-diesel microgrid system needs to consider many factors, such as the prediction and limit of photovoltaic power generation, the status of energy storage equipment, the operating status of diesel generators and load demand. The complexity of these factors may make the implementation of the control strategy difficult and it is difficult to ensure the stability and reliability of the system. The existing technology for the control of photovoltaic-storage-diesel microgrid system mostly adopts a unified management control method, which is not very precise and flexible in controlling the power balance of the photovoltaic-storage-diesel microgrid system.

[0004] Therefore, it is urgent to provide a technical solution to solve the above problems. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a control method, device, electronic device and storage medium for a photovoltaic-storage-diesel microgrid system.

[0006] In a first aspect, the present invention provides a control method for a photovoltaic-storage-diesel microgrid system, and the technical solution of the method is as follows:

[0007] Arrange the energy storage battery rated capacity of each energy storage battery subsystem of the energy storage system in the photovoltaic-storage-diesel microgrid system in descending order to obtain a target sequence, and determine the first non-faulty energy storage battery subsystem in the target sequence as the target energy storage battery subsystem;

[0008] Determine the current photovoltaic power of the photovoltaic power generation system in the photovoltaic-storage-diesel microgrid system according to the current charge state of the target energy storage battery subsystem;

[0009] According to the current load power demand or the current charge state of the photovoltaic-diesel-storage microgrid system, the start / stop state of the diesel generator of the photovoltaic-diesel-storage microgrid system is determined to achieve power balance control of the photovoltaic-diesel-storage microgrid system.

[0010] The beneficial effects of the control method of a photovoltaic-storage-diesel microgrid system of the present invention are as follows:

[0011] The method of the present invention realizes the refined management of the photovoltaic-storage-diesel microgrid system, adjusts the current photovoltaic power and the start and stop of the diesel generator according to the current charge state of the energy storage battery, realizes the auxiliary energy storage of the photovoltaic power generation system and the diesel generator, and improves the stability, power supply reliability, flexibility and service life of the photovoltaic-storage-diesel microgrid system.

[0012] Based on the above scheme, the control method of a photovoltaic-storage-diesel microgrid system of the present invention can also be improved as follows.

[0013] In an optional manner, the method further includes:

[0014] By controlling the charge and discharge state of each energy storage battery subsystem in the target sequence except the target energy storage battery subsystem, the operation mode of the energy storage system is adjusted to utilize the energy storage system to perform the power balance control.

[0015] In the above optional method, by finely controlling the charging and discharging states of different energy storage battery subsystems, the operating mode of the entire energy storage system is optimized and adjusted, which not only improves the utilization rate of the energy storage system, but also enhances the flexibility and efficiency of the system in power balance control.

[0016] In an optional manner, the step of determining the current photovoltaic power of the photovoltaic power generation system in the photovoltaic-storage-diesel microgrid system according to the current state of charge of the target energy storage battery subsystem includes:

[0017] When the current state of charge is greater than a first threshold, taking the current load power demand as the current photovoltaic power;

[0018] When the current state of charge is less than or equal to a second threshold, a maximum value of a preset photovoltaic power range is determined as the current photovoltaic power.

[0019] In the above optional method, the current photovoltaic power output is dynamically adjusted according to the current charge state of the energy storage battery, which can ensure that the current load demand is met when the energy storage battery is sufficiently charged, and photovoltaic power generation can be fully utilized when the energy storage battery is insufficient, thereby improving the utilization rate of photovoltaic power generation and the stability of the system.

[0020] In an optional manner, the step of determining the start / stop state of the diesel generator of the photovoltaic-diesel-storage microgrid system according to the current load power demand or the current state of charge of the photovoltaic-diesel-storage microgrid system includes:

[0021] When the remaining power of the energy storage system is less than the minimum operating remaining power of the energy storage system, and the current load power demand is greater than the diesel generator starting load threshold,

[0022] or,

[0023] When the current state of charge of the target energy storage battery subsystem is less than a third threshold, controlling the diesel generator to start;

[0024] When the current state of charge of the target energy storage battery subsystem is greater than a fourth threshold, the diesel generator is controlled to stop.

[0025] In the above optional method, by accurately monitoring the current state of charge and the current load power demand, the start and stop of the diesel generator can be reasonably controlled to ensure that the diesel generator is started in time when the energy storage battery is insufficient and the load demand is high, and the diesel generator is stopped when the power is sufficient. This not only improves the power supply reliability and stability of the system, but also reduces unnecessary operation of the diesel generator, thereby extending its service life and reducing operating costs.

[0026] In a second aspect, the present invention provides a control device for a photovoltaic-storage-diesel microgrid system, and the technical solution of the device is as follows:

[0027] The photovoltaic-storage-diesel microgrid system control device comprises: a first control module, a second control module and a third control module;

[0028] The first control module is used to: arrange the energy storage battery rated capacity of each energy storage battery subsystem of the energy storage system in the photovoltaic-storage-diesel microgrid system in descending order to obtain a target sequence, and determine the first non-faulty energy storage battery subsystem in the target sequence as the target energy storage battery subsystem;

[0029] The second control module is used to: determine the current photovoltaic power of the photovoltaic power generation system in the photovoltaic-storage-diesel microgrid system according to the current state of charge of the target energy storage battery subsystem;

[0030] The third control module is used to determine the start and stop status of the diesel generator of the photovoltaic, storage and diesel microgrid system according to the current load power demand or the current charge state of the photovoltaic, storage and diesel microgrid system, so as to achieve power balance control of the photovoltaic, storage and diesel microgrid system.

[0031] The beneficial effects of the photovoltaic-storage-diesel microgrid system control device of the present invention are as follows:

[0032] The device of the present invention realizes the refined management of the photovoltaic-storage-diesel microgrid system, adjusts the current photovoltaic power and the start and stop of the diesel generator according to the current charge state of the energy storage battery, realizes the auxiliary energy storage of the photovoltaic power generation system and the diesel generator, and improves the stability, power supply reliability, flexibility and service life of the photovoltaic-storage-diesel microgrid system.

[0033] Based on the above scheme, the control device of the photovoltaic-storage-diesel microgrid system of the present invention can also be improved as follows.

[0034] In an optional manner, the method further includes: a fourth control module, wherein the fourth control module is configured to:

[0035] By controlling the charge and discharge state of each energy storage battery subsystem in the target sequence except the target energy storage battery subsystem, the operation mode of the energy storage system is adjusted to utilize the energy storage system to perform the power balance control.

[0036] In the above optional method, by finely controlling the charging and discharging states of different energy storage battery subsystems, the operating mode of the entire energy storage system is optimized and adjusted, which not only improves the utilization rate of the energy storage system, but also enhances the flexibility and efficiency of the system in power balance control.

[0037] In an optional manner, the second control module is specifically configured to:

[0038] When the current state of charge is greater than a first threshold, taking the current load power demand as the current photovoltaic power;

[0039] When the current state of charge is less than or equal to a second threshold, a maximum value of a preset photovoltaic power range is determined as the current photovoltaic power.

[0040] In the above optional method, the current photovoltaic power output is dynamically adjusted according to the current charge state of the energy storage battery, which can ensure that the current load demand is met when the energy storage battery is sufficiently charged, and photovoltaic power generation can be fully utilized when the energy storage battery is insufficient, thereby improving the utilization rate of photovoltaic power generation and the stability of the system.

[0041] In an optional manner, the third control module is specifically used to:

[0042] When the remaining power of the energy storage system is less than the minimum operating remaining power of the energy storage system, and the current load power demand is greater than the diesel generator starting load threshold,

[0043] or,

[0044] When the current state of charge of the target energy storage battery subsystem is less than a third threshold, controlling the diesel generator to start;

[0045] When the current state of charge of the target energy storage battery subsystem is greater than a fourth threshold, the diesel generator is controlled to stop.

[0046] In the above optional method, by accurately monitoring the state of charge and current load power demand, the start and stop of the diesel generator can be reasonably controlled to ensure that the diesel generator is started in time when the energy storage battery is insufficient and the load demand is high, and the diesel generator is stopped when the power is sufficient. This not only improves the power supply reliability and stability of the system, but also reduces unnecessary operation of the diesel generator, thereby extending its service life and reducing operating costs.

[0047] In a third aspect, a technical solution of an electronic device of the present invention is as follows:

[0048] It includes a memory, a processor, and a program stored in the memory and running on the processor. When the processor executes the program, the steps of the control method of the photovoltaic-storage-diesel microgrid system of the present invention are implemented.

[0049] In a fourth aspect, the present invention provides a computer-readable storage medium having the following technical solution:

[0050] Instructions are stored in the computer-readable storage medium. When the computer-readable storage medium reads the instructions, the computer-readable storage medium executes the steps of the control method of the photovoltaic-energy-storage-diesel microgrid system of the present invention.

[0051] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] The accompanying drawings are only used to illustrate the embodiments and are not to be considered as limiting the present invention. In addition, the same reference symbols are used to represent the same components throughout the accompanying drawings. In the accompanying drawings:

[0053] Figure 1 A schematic flow chart of an embodiment of a control method for a photovoltaic-storage-diesel microgrid system of the present invention;

[0054] Figure 2 A schematic diagram of the start and stop control flow of the energy storage battery subsystem;

[0055] Figure 3 This is a schematic diagram of the overall control process of the photovoltaic, storage and diesel microgrid system;

[0056] Figure 4 It is a structural schematic diagram of an embodiment of a control device for a photovoltaic-storage-diesel microgrid system of the present invention;

[0057] Figure 5 The figure is a schematic structural diagram of an embodiment of an electronic device of the present invention. DETAILED DESCRIPTION

[0058] Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0059] Figure 1The flowchart of an embodiment of a control method for a photovoltaic-storage-diesel microgrid system provided by the present invention is shown, and the method is executed by a controller. Figure 1 As shown, the following steps are included:

[0060] S1. Arrange the rated capacity of each energy storage battery subsystem of the energy storage system in the photovoltaic-storage-diesel microgrid system in descending order to obtain a target sequence, and determine the first non-faulty energy storage battery subsystem in the target sequence as the target energy storage battery subsystem. In S1:

[0061] 1) The photovoltaic-storage-diesel microgrid system is a microgrid system that includes an energy storage system, a photovoltaic power generation system, a diesel generator and a load. It can achieve power balance and meet load demand through coordinated control. By integrating photovoltaic power generation, energy storage batteries and diesel generators, the photovoltaic-storage-diesel microgrid system can autonomously adjust and distribute power in off-grid mode to ensure stable operation of the system. The photovoltaic power generation system adjusts the output power according to the state of the energy storage system and the load demand, and the diesel generator starts or stops according to the power demand and energy storage state of the photovoltaic-storage-diesel microgrid system to achieve power balance control of the entire system.

[0062] 2) The energy storage battery subsystem is a subsystem in the energy storage system. Each energy storage battery subsystem includes energy storage batteries and energy storage inverters, which are responsible for the storage and release of energy. The energy storage battery subsystem is used to store energy when the load demand is low, and release energy when the load demand is high or the photovoltaic power generation is insufficient, to ensure the power balance of the photovoltaic-storage-diesel microgrid system. Different energy storage battery subsystems have different rated capacities, and the photovoltaic-storage-diesel microgrid system is prioritized and controlled according to the capacity. At the same time, the energy storage inverter can work together in the voltage source mode in the off-grid mode, and the failure of a single energy storage inverter will not affect the normal operation of other energy storage battery subsystems.

[0063] 3) The rated capacity of the energy storage battery is the maximum amount of electricity that the energy storage battery subsystem can store, which represents the capacity of the energy storage battery. According to the rated capacity of the energy storage battery, the priority of each subsystem in power balance control is determined by arranging different energy storage battery subsystems in descending order. The subsystem with a higher rated capacity plays a more important role in power balance. At the same time, the subsystem with a lower rated capacity will be started and stopped first when the charge and discharge cut-off threshold is reached to protect the battery and maintain system stability.

[0064] 4) The target sequence is a sequence obtained by arranging all energy storage battery subsystems in descending order according to the rated capacity of the energy storage batteries of each energy storage battery subsystem in the photovoltaic-storage-diesel microgrid system. The target sequence is used to determine which energy storage battery subsystem is prioritized as the main executor of power balance control. By arranging the energy storage battery subsystems from high to low according to the rated capacity, the photovoltaic-storage-diesel microgrid system uses the first non-faulty energy storage battery subsystem as the target energy storage battery subsystem to ensure that the system gives priority to the energy storage resource with the largest capacity when adjusting power.

[0065] 5) The target energy storage battery subsystem is the first non-faulty energy storage battery subsystem in the target sequence and is identified as the main executor of the power balance control of the current photovoltaic-storage-diesel microgrid system. The target energy storage battery subsystem plays a key role in the power control of the photovoltaic-storage-diesel microgrid system. The current state of charge (SOC) of the target energy storage battery subsystem is used to determine the photovoltaic power output of the photovoltaic power generation system (i.e., the current photovoltaic power), and together with the start and stop status of the diesel generator, determines the power balance control strategy of the system. In addition, the state of the target energy storage battery subsystem (such as the charge and discharge state) will affect the control and regulation of other energy storage subsystems to ensure the stable operation of the entire system.

[0066] Specifically, the controller arranges the rated capacity of the energy storage batteries of each energy storage battery subsystem of the energy storage system in the photovoltaic-diesel-storage microgrid system in descending order to obtain a target sequence, and determines the first non-faulty energy storage battery subsystem in the target sequence as the target energy storage battery subsystem.

[0067] S2. According to the current state of charge of the target energy storage battery subsystem, determine the current photovoltaic power of the photovoltaic power generation system in the photovoltaic-storage-diesel microgrid system. In S2:

[0068] 1) The current state of charge refers to the current remaining power in the energy storage battery subsystem, usually expressed as a percentage, reflecting the ratio of the remaining power of the energy storage battery to the maximum capacity of the energy storage battery. The current state of charge plays an important role in determining the operation mode of the photovoltaic-storage-diesel microgrid system in control. According to the value of the current state of charge, the photovoltaic-storage-diesel microgrid system can decide how to adjust the current photovoltaic power of the photovoltaic power generation system, whether to start or stop the diesel generator, and how to perform power balance control.

[0069] 2) Photovoltaic power generation system refers to a power generation system that uses solar photovoltaic modules to convert sunlight energy into electrical energy. The main function of the photovoltaic power generation system is to provide renewable energy for the photovoltaic-storage-diesel microgrid system, and to convert solar energy into electrical energy for the photovoltaic-storage-diesel microgrid system through photovoltaic modules. The output power (current photovoltaic power) of the photovoltaic power generation system will be adjusted according to the current charge state of the energy storage battery and the current load demand to achieve power balance control and optimize the operation of the photovoltaic-storage-diesel microgrid system.

[0070] 3) Current photovoltaic power refers to the electrical power output by the photovoltaic power generation system at a certain moment. The current photovoltaic power plays a role in regulating the power supply in the photovoltaic-storage-diesel microgrid system. Depending on the current state of charge, the output of the current photovoltaic power can be limited or maximized.

[0071] Specifically, the controller further determines the current photovoltaic power of the photovoltaic power generation system in the photovoltaic-storage-diesel microgrid system according to the current state of charge of the target energy storage battery subsystem.

[0072] S3, according to the current load power demand or current charge state of the photovoltaic-storage-diesel microgrid system, determine the start and stop state of the diesel generator of the photovoltaic-storage-diesel microgrid system to achieve power balance control of the photovoltaic-storage-diesel microgrid system. In S3:

[0073] 1) The current load power demand refers to the total power required by the electrical equipment currently served by the photovoltaic-storage-diesel microgrid system. The current load power demand is an important reference indicator for the photovoltaic-storage-diesel microgrid system to perform power balance control. The photovoltaic-storage-diesel microgrid system decides whether to start the diesel generator, how to adjust the current photovoltaic power, and how to control the charge and discharge state of the energy storage battery based on the current load power demand and the state of the energy storage system (such as the current state of charge) to meet the load demand and maintain system stability.

[0074] 2) Diesel generators are power generation equipment that uses diesel as fuel and can provide power support when renewable energy is insufficient. Diesel generators act as backup power sources in the photovoltaic-storage-diesel microgrid system. When the energy storage system is insufficient and the photovoltaic power generation system cannot meet the load demand, the diesel generator will start to provide additional power. Starting and stopping the diesel generator depends on the current charge state of the energy storage system and the current load power demand.

[0075] 3) Power balance control refers to the process of adjusting the output power of different power sources (photovoltaic power generation system, energy storage battery subsystem, and diesel generator) in the photovoltaic-storage-diesel microgrid system to ensure that the total power generation of the system matches the current load power demand, so as to maintain the power balance and stable operation of the photovoltaic-storage-diesel microgrid system. Power balance control is the core goal of the operation of the entire photovoltaic-storage-diesel microgrid system. Through power balance control, the photovoltaic-storage-diesel microgrid system can adjust the operating status of each subsystem according to the current load power demand, the current photovoltaic power, the current state of charge of the energy storage battery, and the state of the diesel generator, ensuring that the photovoltaic-storage-diesel microgrid system can operate stably under various working conditions. Power balance control includes: determining the current photovoltaic power according to the current state of charge; controlling the charge and discharge state of the energy storage battery subsystem; determining the start and stop of the diesel generator; thereby ensuring that the current load power demand is met, while protecting the energy storage battery and the diesel generator to avoid overcharging, over-discharging, or unnecessary fuel consumption.

[0076] 4) The goal of power balance control is to ensure that the total power generation of the photovoltaic-storage-diesel microgrid system matches the current load power demand. Specifically, the total power generation includes: the output power of the photovoltaic power generation system (current photovoltaic power), the current energy storage system power, and the output power of the diesel generator. Among them, the power of each energy storage battery subsystem in the energy storage system is negative when charging and positive when discharging. Therefore, the goal of power balance control is to keep the total power generation consistent with the current load power demand. When the total power generation is less than the current load power demand, the photovoltaic-storage-diesel microgrid system supplements the power difference by increasing the power generation unit (such as starting the diesel generator) and discharging the energy storage battery subsystem in the energy storage system. At this time, the total power generation is less than the load demand until the adjustment is completed. When the total power generation is greater than the current load power demand, the photovoltaic-storage-diesel microgrid system absorbs excess power by reducing the output of the power generation unit (such as stopping the diesel generator) and charging the energy storage battery subsystem in the energy storage system. At this time, the total power generation is greater than the current load power demand. When the total power generation is equal to the current load power demand, the photovoltaic-storage-diesel microgrid system achieves power balance.

[0077] Furthermore, when the current load power demand is greater than the total power generation of the photovoltaic power generation system and the energy storage battery subsystem, the output power of the diesel generator is increased, or the missing power is supplemented by discharging the energy storage battery, so that the total power generation meets the current load power demand.

[0078] When the current load power demand is less than the total power generation of the photovoltaic power generation system and the energy storage battery subsystem, the output power of the diesel generator is reduced, or the excess power is absorbed by charging the energy storage battery to avoid excess power.

[0079] Through the above-mentioned adjustment process, the photovoltaic-storage-diesel microgrid system can dynamically adjust the output power of each power generation unit to ensure the power balance of the photovoltaic-storage-diesel microgrid system under different load conditions and ensure the stable operation of the power grid.

[0080] Specifically, the controller further determines the start / stop state of the diesel generator of the PV-diesel-storage microgrid system according to the current load power demand or current charge state of the PV-diesel-storage microgrid system, so as to realize power balance control of the PV-diesel-storage microgrid system.

[0081] The technical solution of this embodiment realizes the refined management of the photovoltaic-storage-diesel microgrid system, adjusts the current photovoltaic power and the start and stop of the diesel generator according to the current charge state of the energy storage battery, realizes the joint auxiliary energy storage of the photovoltaic power generation system and the diesel generator, and improves the stability, power supply reliability, flexibility and service life of the photovoltaic-storage-diesel microgrid system.

[0082] In this embodiment, for the convenience of explanation, the corresponding relationship is as follows:

[0083] The current load power demand is P load , the current photovoltaic power is P pv , the output power of the diesel generator is P G , the total energy storage power is P bat , the current photovoltaic power (the photovoltaic power limit value) is P pv_Limit , assuming that the energy storage system includes: a first energy storage battery subsystem and a second energy storage battery subsystem, the rated capacity of the energy storage battery of the first energy storage battery subsystem is greater than the rated capacity of the energy storage battery of the second energy storage battery subsystem, and both of the above energy storage battery subsystems are not faulty. The total state of charge of the energy storage system is SOC, the state of charge of the second energy storage battery subsystem is SOC1, and the corresponding energy storage converter is PCS1; the state of charge of the first energy storage battery subsystem is SOC2, and the corresponding energy storage converter is PCS2. The total remaining energy of the two energy storage battery subsystems (i.e., the remaining power of the energy storage system) is E bat , SOC th1 is the upper limit of the state of charge threshold of the energy storage battery (i.e., the first threshold), SOC th2 is the upper limit of the charge state of the energy storage battery, the hysteresis threshold 2 (i.e., the second threshold), SOC th4 The upper limit of the charge state threshold of the energy storage battery is 4 (i.e., the fourth threshold), SOC th3 The SOC is the lower limit of the energy storage battery discharge state of charge threshold 3 (i.e. the third threshold), th5 is the energy storage battery state of charge threshold 5 (i.e., the fifth threshold), P loadth1 is the diesel generator start-up load threshold. At the same time, the energy storage discharge is specified to be in the positive direction. Therefore, according to the law of energy conservation, the current load power demand is the sum of the power of the energy storage system, photovoltaic power generation system and diesel generator, that is, P load =P G +P pv +P bat .

[0084] In an optional manner, the method further includes:

[0085] By controlling the charge and discharge state of each energy storage battery subsystem except the target energy storage battery subsystem in the target sequence, the operation mode of the energy storage system is adjusted to utilize the energy storage system for power balance control.

[0086] It should be noted that, assuming that the energy storage system includes: a first energy storage battery subsystem and a second energy storage battery subsystem, the rated capacity of the energy storage battery of the first energy storage battery subsystem is greater than the rated capacity of the energy storage battery of the second energy storage battery subsystem, and both of the above energy storage battery subsystems are not faulty, the start and shutdown control of the second energy storage battery subsystem needs to be controlled according to the operating status of the photovoltaic-diesel microgrid system and the current state of charge of the energy storage battery. In addition, in the case of only two energy storage battery subsystems, if the first energy storage battery subsystem fails, the second energy storage battery subsystem is directly used as the main basis for determining the operation of the photovoltaic-diesel microgrid system, and the start and shutdown control of the second energy storage battery subsystem is not performed.

[0087] The start and stop control of the second energy storage battery subsystem includes two situations:

[0088] ① Shutdown condition: When the second energy storage battery subsystem reaches the energy storage battery full cut-off threshold in advance, it will shut down;

[0089] Restart conditions: If the first energy storage battery subsystem is in a discharging state and the current power of the second energy storage battery subsystem is sufficient to support the operation of the photovoltaic-storage-diesel microgrid system, the second energy storage battery subsystem starts discharging.

[0090] ②Shutdown condition: Shutdown when the second energy storage battery subsystem reaches the battery discharge cut-off threshold in advance;

[0091] Restart conditions: If the first energy storage battery subsystem is in a charging state and the current power of the second energy storage battery subsystem is sufficient to support the operation of the photovoltaic-storage-diesel microgrid system, the second energy storage battery subsystem starts charging.

[0092] In this embodiment, the energy storage system includes: a first energy storage battery subsystem and a second energy storage battery subsystem. The rated capacity of the energy storage battery of the first energy storage battery subsystem is greater than the rated capacity of the energy storage battery of the second energy storage battery subsystem, and both of the above energy storage battery subsystems are not faulty. When there are energy storage battery subsystems with different rated capacities in the photovoltaic-diesel microgrid system, the start and stop control of the second energy storage battery subsystem needs to be considered. The start and stop control flow chart of the energy storage battery subsystem is shown in FIG. Figure 2 It mainly involves two working conditions: charging cut-off and discharging cut-off of the energy storage system.

[0093] ① When the second energy storage battery subsystem reaches the energy storage battery full cut-off threshold in advance (i.e. SOC1>SOC th1 ) when the machine is shut down.

[0094] When the current power of the second energy storage battery subsystem can support the operation of the photovoltaic storage diesel microgrid system, that is, the state of charge SOC1 of the second energy storage battery subsystem ≥ SOC th5When the first energy storage battery subsystem is in a discharging state, the second energy storage battery subsystem starts discharging.

[0095] ② When the second energy storage battery subsystem reaches the battery discharge cut-off threshold in advance (i.e. SOC1<SOC th3 ) when the machine is shut down.

[0096] When the current power of the second energy storage battery subsystem is insufficient, that is, the state of charge SOC1 of the second energy storage battery subsystem is less than SOC th5 When the first energy storage battery subsystem is in a charging state, the energy storage battery subsystem with a smaller rated capacity of the energy storage battery starts charging.

[0097] Before starting the discharge operation or charging operation, the second energy storage battery subsystem can set the delay time according to the preset time in order to maintain the overall charge state of the photovoltaic-storage-diesel microgrid system stable. At the same time, when starting the discharge or charging, the second energy storage battery subsystem gives priority to the current operating state of the internal energy storage converter for operating condition determination.

[0098] Specifically, the controller further adjusts the operation mode of the energy storage system by controlling the charge and discharge state of each energy storage battery subsystem except the target energy storage battery subsystem in the target sequence, so as to utilize the energy storage system for power balance control.

[0099] In an optional manner, the step of determining the current photovoltaic power of the photovoltaic power generation system in the photovoltaic-storage-diesel microgrid system according to the current state of charge of the target energy storage battery subsystem includes:

[0100] When the current state of charge is greater than a first threshold, the current load power demand is used as the current photovoltaic power;

[0101] When the current state of charge is less than or equal to the second threshold, a maximum value of the preset photovoltaic power range is determined as the current photovoltaic power.

[0102] In this embodiment, in the control of the photovoltaic-diesel microgrid system, the first energy storage battery subsystem is preferentially selected as the target energy storage battery subsystem, and the current state of charge SOC2 of the target energy storage battery subsystem is used as the main basis for determining the operation of the photovoltaic-diesel microgrid system. If the first energy storage battery subsystem fails, it is automatically switched to the second energy storage battery subsystem as the target energy storage battery subsystem, and the current state of charge SOC1 of the target energy storage battery subsystem at this time is used as the basis for determination. The photovoltaic power generation system can take power limiting measures according to the current state of charge of the energy storage battery, and coordinate the start and stop of the diesel generator in combination with the current load power demand.

[0103] like Figure 3As shown, assuming that the first energy storage battery subsystem has not failed, the first energy storage battery subsystem is used as the target energy storage battery subsystem. At this time, the current state of charge SOC2 of the target energy storage battery subsystem is used as the main basis for determining the operation of the photovoltaic-storage-diesel microgrid system, as follows:

[0104] ① When the current state of charge of the target energy storage battery subsystem is greater than the first threshold, that is, SOC2>SOC th1 When the photovoltaic power generation system is running at limited power, the power limit value of the photovoltaic power generation system (i.e. the current photovoltaic power) is the current load power demand value, i.e. P pv_Limit =P load . The diesel generator is not started at this time.

[0105] ② When the current state of charge of the target energy storage battery subsystem is less than or equal to the second threshold, that is, SOC2≤SOC th2 The photovoltaic power generation system always maintains maximum power operation.

[0106] Furthermore, in actual control, the first threshold SOC th1 and the second threshold SOC th2 Hysteresis control is used between th1 and SOC th2 are two different state-of-charge thresholds and meet SOC th1 ≥SOC th2 When the photovoltaic power generation system is operating at limited power, the current state of charge SOC2 of the target energy storage battery subsystem is less than the first threshold SOC th1 When the current state of charge SOC2 of the target energy storage battery subsystem is less than the second threshold SOC th2 The photovoltaic power generation system always maintains maximum power operation.

[0107] On the contrary, when the current state of charge SOC2 of the target energy storage battery subsystem is less than the second threshold SOC th2 When the current state of charge SOC2 of the target energy storage battery subsystem continues to rise with the charging process, when the current state of charge SOC2 of the target energy storage battery subsystem is greater than the second threshold SOC th2 When the photovoltaic power generation system maintains the current state, that is, the maximum power operation, until the current state of charge SOC2 of the target energy storage battery subsystem is greater than the first threshold SOC th1 , the photovoltaic power generation system operates at limited power.

[0108] It should be noted that hysteresis control is a nonlinear control method used to prevent the energy storage system from frequently switching states near a certain threshold. Hysteresis control is achieved by setting two different thresholds: one is used to trigger a certain action, and the other is used to restore the original state, thereby effectively preventing the energy storage system from oscillating or frequently switching near critical conditions, and improving the stability and reliability of the energy storage system. Furthermore, the role of hysteresis control is to prevent the photovoltaic power generation system from frequently switching between limited power operation and maximum power operation when the energy storage system is close to the upper limit of charging.

[0109] Specifically, the controller further uses the current load power demand as the current photovoltaic power when the current state of charge is greater than the first threshold; and determines the maximum value of the preset photovoltaic power range as the current photovoltaic power when the current state of charge is less than or equal to the second threshold.

[0110] In an optional manner, the step of determining the start / stop state of the diesel generator of the photovoltaic-storage-diesel microgrid system according to the current load power demand or current charge state of the photovoltaic-storage-diesel microgrid system includes:

[0111] When the remaining power of the energy storage system is less than the minimum remaining power of the energy storage system, and the current load power demand is greater than the diesel generator starting load threshold,

[0112] or,

[0113] When the current state of charge of the target energy storage battery subsystem is less than a third threshold, controlling the diesel generator to start;

[0114] When the current state of charge of the target energy storage battery subsystem is greater than a fourth threshold, the diesel generator is controlled to stop.

[0115] In this embodiment, when the current state of charge SOC of the energy storage system is low (for example, when the remaining power of the energy storage system is less than the minimum remaining power of the energy storage system, that is, E bat <E th1 When there is a large load in the system, that is, P load >P loadth1 Or, when the current state of charge SOC2 of the target energy storage battery subsystem is less than the third threshold SOC th3 , that is, SOC2<SOC th3 When the power is on, the diesel generator starts and the photovoltaic power generation system keeps running at maximum power.

[0116] The output power of the diesel generator must meet the current load power demand, the energy storage system charging power demand and the photovoltaic power generation system power, that is, P G =P load -P pv -P' bat ; Among them, P'bat The charging power requirement for the energy storage system refers to the parameter used to describe how much power the energy storage system needs to obtain from the diesel generator to charge when the diesel generator is started. When the diesel generator is working, P' bat It is dynamic and can be adjusted according to the current state of charge (SOC) of the energy storage system and the working time of the diesel generator, so as to ensure that the energy storage system can reach a fully charged state (i.e., SOC = 100%) within the specified time. th1 It can be set according to the minimum remaining power of the energy storage system, which defaults to 20% of the rated total energy of the energy storage system. loadth1 It can be set according to the load occupancy rate, and the default is 50% of the rated load.

[0117] When the current state of charge of the target energy storage battery subsystem is greater than the fourth threshold, that is, SOC2>SOC th4 The diesel generator shuts down.

[0118] Specifically, the controller further controls the diesel generator to start when the remaining power of the energy storage system is less than the minimum operating remaining power of the energy storage system and the current load power demand is greater than the diesel generator start load threshold, or when the current state of charge of the target energy storage battery subsystem is less than the third threshold; and controls the diesel generator to stop when the current state of charge of the target energy storage battery subsystem is greater than the fourth threshold.

[0119] It should be noted that the goal of power balance control is to ensure that the total power generation of the photovoltaic-storage-diesel microgrid system (including the photovoltaic power generation system, the energy storage battery subsystem and the diesel generator power) matches the current load power demand, that is: P load =P G +P pv +P bat ; Among them: P load is the current load power demand; P G is the output power of the diesel generator; P pv is the output power of the photovoltaic power generation system (current photovoltaic power); P bat It is the power of the energy storage battery subsystem, which is negative during charging and positive during discharging.

[0120] The solar-storage-diesel microgrid system determines the current power balance state based on the following conditions:

[0121] If P load =P pv +P bat , the solar-storage-diesel microgrid system has reached power balance and does not require further adjustment.

[0122] If P load ≠P pv +Pbat , it is necessary to achieve power balance by adjusting the output power of the energy storage battery and the diesel generator.

[0123] Figure 4 FIG. 2 is a schematic diagram showing a structure of an embodiment of a photovoltaic-storage-diesel microgrid system control device 200 provided by the present invention. Figure 4 As shown, the device 200 includes: a first control module 210, a second control module 220 and a third control module 230;

[0124] The first control module 210 is used to: arrange the energy storage battery rated capacity of each energy storage battery subsystem of the energy storage system in the photovoltaic-storage-diesel microgrid system in descending order to obtain a target sequence, and determine the first non-faulty energy storage battery subsystem in the target sequence as the target energy storage battery subsystem;

[0125] The second control module 220 is used to: determine the current photovoltaic power of the photovoltaic power generation system in the photovoltaic-storage-diesel microgrid system according to the current charge state of the target energy storage battery subsystem;

[0126] The third control module 230 is used to determine the start / stop state of the diesel generator of the PV-diesel-storage microgrid system according to the current load power demand or current charge state of the PV-diesel-storage microgrid system, so as to realize power balance control of the PV-diesel-storage microgrid system.

[0127] In an optional manner, the method further includes: a fourth control module, the fourth control module being configured to:

[0128] By controlling the charge and discharge state of each energy storage battery subsystem except the target energy storage battery subsystem in the target sequence, the operation mode of the energy storage system is adjusted to utilize the energy storage system for power balance control.

[0129] In an optional manner, the second control module is specifically used to:

[0130] When the current state of charge is greater than a first threshold, the current load power demand is used as the current photovoltaic power;

[0131] When the current state of charge is less than or equal to the second threshold, a maximum value of the preset photovoltaic power range is determined as the current photovoltaic power.

[0132] In an optional manner, the third control module is specifically used to:

[0133] When the remaining power of the energy storage system is less than the minimum remaining power of the energy storage system, and the current load power demand is greater than the diesel generator starting load threshold,

[0134] or,

[0135] When the current state of charge of the target energy storage battery subsystem is less than a third threshold, controlling the diesel generator to start;

[0136] When the current state of charge of the target energy storage battery subsystem is greater than a fourth threshold, the diesel generator is controlled to stop.

[0137] The technical solution of this embodiment realizes the refined management of the photovoltaic-storage-diesel microgrid system, adjusts the current photovoltaic power and the start and stop of the diesel generator according to the current charge state of the energy storage battery, realizes the joint auxiliary energy storage of the photovoltaic power generation system and the diesel generator, and improves the stability, power supply reliability, flexibility and service life of the photovoltaic-storage-diesel microgrid system.

[0138] The above-mentioned parameters in the photovoltaic-diesel-storage microgrid system control device 200 of this embodiment and the steps for each module to implement the corresponding functions can refer to the parameters and steps in the embodiment of the photovoltaic-diesel-storage microgrid system control method above, and will not be repeated here.

[0139] like Figure 5 As shown, an electronic device 300 of an embodiment of the present invention includes a processor 320, the processor 320 is coupled to a memory 310, and the memory 310 stores at least one computer program 330, and the at least one computer program 330 is loaded and executed by the processor 320, so that the electronic device 300 implements any of the above-mentioned methods for controlling a photovoltaic-storage-diesel microgrid system, specifically:

[0140] The electronic device 300 may have relatively large differences due to different configurations or performances, and may include one or more processors 320 (Central Processing Units, CPU) and one or more memories 310, wherein the one or more memories 310 store at least one computer program 330, and the at least one computer program 330 is loaded and executed by the one or more processors 320, so that the electronic device 300 implements any of the control methods for the photovoltaic-storage-diesel microgrid system provided in the above embodiments. Of course, the electronic device 300 may also have components such as a wired or wireless network interface, a keyboard, and an input and output interface for input and output, and the electronic device 300 may also include other components for implementing device functions, which will not be described in detail here.

[0141] A computer-readable storage medium in an embodiment of the present invention stores at least one computer program, and the at least one computer program is loaded and executed by a processor so that a computer implements any of the above-mentioned methods for controlling a photovoltaic-storage-diesel microgrid system.

[0142] Optionally, the computer-readable storage medium may be a read-only memory (ROM), a random access memory (RAM), a compact disc (CD-ROM), a magnetic tape, a floppy disk, an optical data storage device, and the like.

[0143] In an exemplary embodiment, a computer program product or a computer program is also provided, the computer program product or the computer program comprising computer instructions, the computer instructions being stored in a computer-readable storage medium. A processor of an electronic device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, so that the electronic device executes any of the above-mentioned methods for controlling a photovoltaic-storage-diesel microgrid system.

[0144] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects and represent the definition of a specific order or sequence. The order of use of similar objects can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than the order shown or described.

[0145] Those skilled in the art know that the present invention can be implemented as an apparatus, method or computer program product. Therefore, the present disclosure can be specifically implemented in the following forms, namely: it can be complete hardware, it can be complete software (including firmware, resident software, microcode, etc.), or it can be a combination of hardware and software, which is generally referred to as "circuit", "module" or "apparatus" herein. In addition, in some embodiments, the present invention can also be implemented in the form of a computer program product in one or more computer-readable media, and the computer-readable medium contains computer-readable program code.

[0146] Any combination of one or more computer-readable media may be used. A computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. A computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor device, apparatus or device, or any combination thereof. More specific examples (a non-exhaustive list) of computer-readable storage media include: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In the present application, a computer-readable storage medium may be any tangible medium containing or storing a program that may be used by or in conjunction with an instruction execution device, apparatus, or device.

[0147] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A control method for a photovoltaic-storage-diesel microgrid system, characterized in that: include: Arrange the energy storage battery rated capacity of each energy storage battery subsystem of the energy storage system in the photovoltaic-storage-diesel microgrid system in descending order to obtain a target sequence, and determine the first non-faulty energy storage battery subsystem in the target sequence as the target energy storage battery subsystem; Determine the current photovoltaic power of the photovoltaic power generation system in the photovoltaic-storage-diesel microgrid system according to the current charge state of the target energy storage battery subsystem; According to the current load power demand or the current charge state of the photovoltaic-diesel-storage microgrid system, the start / stop state of the diesel generator of the photovoltaic-diesel-storage microgrid system is determined to achieve power balance control of the photovoltaic-diesel-storage microgrid system.

2. The control method of the photovoltaic-storage-diesel microgrid system according to claim 1 is characterized in that: Also includes: By controlling the charge and discharge state of each energy storage battery subsystem in the target sequence except the target energy storage battery subsystem, the operation mode of the energy storage system is adjusted to utilize the energy storage system to perform the power balance control.

3. The control method of the photovoltaic-storage-diesel microgrid system according to claim 1 is characterized in that: The step of determining the current photovoltaic power of the photovoltaic power generation system in the photovoltaic-storage-diesel microgrid system according to the current charge state of the target energy storage battery subsystem comprises: When the current state of charge is greater than a first threshold, taking the current load power demand as the current photovoltaic power; When the current state of charge is less than or equal to a second threshold, a maximum value of a preset photovoltaic power range is determined as the current photovoltaic power.

4. The control method of the photovoltaic-storage-diesel microgrid system according to claim 1 is characterized in that: The step of determining the start / stop state of the diesel generator of the photovoltaic-storage-diesel microgrid system according to the current load power demand or the current state of charge of the photovoltaic-storage-diesel microgrid system comprises: When the remaining power of the energy storage system is less than the minimum operating remaining power of the energy storage system, and the current load power demand is greater than the diesel generator starting load threshold, or, When the current state of charge of the target energy storage battery subsystem is less than a third threshold, controlling the diesel generator to start; When the current state of charge of the target energy storage battery subsystem is greater than a fourth threshold, the diesel generator is controlled to stop.

5. A control device for a photovoltaic-storage-diesel microgrid system, characterized in that: include: A first control module, a second control module and a third control module; The first control module is used to: arrange the energy storage battery rated capacity of each energy storage battery subsystem of the energy storage system in the photovoltaic-storage-diesel microgrid system in descending order to obtain a target sequence, and determine the first non-faulty energy storage battery subsystem in the target sequence as the target energy storage battery subsystem; The second control module is used to: determine the current photovoltaic power of the photovoltaic power generation system in the photovoltaic-storage-diesel microgrid system according to the current state of charge of the target energy storage battery subsystem; The third control module is used to determine the start and stop status of the diesel generator of the photovoltaic, storage and diesel microgrid system according to the current load power demand or the current charge state of the photovoltaic, storage and diesel microgrid system, so as to achieve power balance control of the photovoltaic, storage and diesel microgrid system.

6. A photovoltaic-storage-diesel microgrid system control device according to claim 5, characterized in that: Also includes: A fourth control module, wherein the fourth control module is used for: By controlling the charge and discharge state of each energy storage battery subsystem in the target sequence except the target energy storage battery subsystem, the operation mode of the energy storage system is adjusted to utilize the energy storage system to perform the power balance control.

7. The control device for a photovoltaic-storage-diesel microgrid system according to claim 5 is characterized in that: The second control module is specifically used for: When the current state of charge is greater than a first threshold, taking the current load power demand as the current photovoltaic power; When the current state of charge is less than or equal to a second threshold, a maximum value of a preset photovoltaic power range is determined as the current photovoltaic power.

8. The control device for a photovoltaic-storage-diesel microgrid system according to claim 5 is characterized in that: The third control module is specifically used for: When the remaining power of the energy storage system is less than the minimum operating remaining power of the energy storage system, and the current load power demand is greater than the diesel generator starting load threshold, or, When the current state of charge of the target energy storage battery subsystem is less than a third threshold, controlling the diesel generator to start; When the current state of charge of the target energy storage battery subsystem is greater than a fourth threshold, the diesel generator is controlled to stop.

9. An electronic device, characterized in that: The electronic device includes a processor, the processor is coupled to a memory, at least one computer program is stored in the memory, and the at least one computer program is loaded and executed by the processor so that the electronic device implements the control method of the photovoltaic-storage-diesel microgrid system as described in any one of claims 1 to 4.

10. A computer-readable storage medium, characterized in that: At least one computer program is stored in the computer-readable storage medium, and the at least one computer program is loaded and executed by the processor so that the computer-readable storage medium implements the control method of the photovoltaic-storage-diesel microgrid system as described in any one of claims 1 to 4.

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