Optical storage diesel load integrated multi-source cooperative control method and optical storage diesel load integrated system

Abstract

The invention relates to the technical field of micro-grids, and discloses an optical storage diesel load integrated multi-source cooperative control method and an optical storage diesel load integrated system.The optical storage diesel load integrated multi-source cooperative control method comprises the steps that the working mode of the optical storage diesel load integrated system is switched according to the remaining electric quantity of an energy storage system and the power generation power of a photovoltaic system, the working mode comprises a first off-network mode and a second off-network mode; when the photovoltaic-energy-storage-diesel-load integrated system is switched to operate in the first off-grid mode, the energy storage system is controlled to operate in a VSG mode, and the power generation power of the photovoltaic system is adjusted according to the remaining electric quantity of the energy storage system; and when the light-storage diesel-load integrated system is switched to the second off-grid mode to operate, controlling the diesel-generator system to operate in the VSG mode, and charging the energy storage system by taking the load rate upper limit of the diesel-generator system as a target. By optimizing a scheduling algorithm and an intelligent control method, the problem that the system is poor in performance in the aspects of frequency stability, load balance and economic operation is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of microgrids, and in particular to a photovoltaic, storage, diesel and load integrated multi-source collaborative control method and a photovoltaic, storage, diesel and load integrated system. Background Art

[0002] With the rapid development of renewable energy and the increase in energy demand, photovoltaic, storage, diesel and load integrated systems have been widely used due to their high efficiency, flexibility and reliability. However, the existing control strategies are insufficient in multi-source coordinated control, resulting in poor performance of the system in terms of frequency stability, load balancing and economic operation. Summary of the invention

[0003] In view of this, the present invention provides a photovoltaic, storage, diesel and load integrated multi-source collaborative control method and a photovoltaic, storage, diesel and load integrated system to solve the problem that the existing control strategy is insufficient in multi-source collaborative control.

[0004] In a first aspect, the present invention provides a photovoltaic, storage, diesel and load integrated multi-source coordinated control method, which is applied to a photovoltaic, storage, diesel and load integrated system, and the method comprises:

[0005] Switching the working mode of the photovoltaic energy storage and diesel load integrated system according to the remaining power of the energy storage system and the power generation power of the photovoltaic system, wherein the working mode includes a first off-grid mode and a second off-grid mode;

[0006] When the photovoltaic-storage-diesel-load integrated system switches to the first off-grid mode, the energy storage system is controlled to operate in the VSG mode, and the power generation power of the photovoltaic system is adjusted according to the remaining power of the energy storage system;

[0007] When the integrated solar-storage-diesel-load system switches to the second off-grid mode, the diesel-generator system is controlled to operate in VSG mode, and the energy storage system is charged with the goal of not exceeding the load rate upper limit of the diesel-generator system.

[0008] The present invention provides a photovoltaic, storage, diesel and load integrated multi-source collaborative control method, which realizes efficient operation and energy management of the system by optimizing the scheduling algorithm and intelligent control method. The control method has significant advantages in frequency regulation, load balancing, economic scheduling and fault recovery, and is suitable for a variety of application scenarios, such as microgrids, emergency power supplies and industrial applications. Through reasonable design and optimization, the control method can improve the stability and economy of the system.

[0009] In an optional implementation, the operation mode of the photovoltaic-storage-diesel-load integrated system is switched according to the remaining power of the energy storage system and the power generation power of the photovoltaic system, including:

[0010] When the remaining power of the energy storage system is not less than the first set value and the power generation power of the photovoltaic system is greater than the load power, the photovoltaic storage diesel load integrated system is switched to the first off-grid mode;

[0011] When the remaining power of the energy storage system is less than a second set value, the photovoltaic storage and diesel load integrated system is switched to a second off-grid mode, and the second set value is less than the first set value.

[0012] In an optional implementation, when the photovoltaic-storage-diesel-load integrated system is switched to the first off-grid mode, the energy storage system is controlled to operate in the VSG mode, and the power generation power of the photovoltaic system is adjusted according to the remaining power of the energy storage system, including:

[0013] When the remaining power of the energy storage system is greater than a third set value, the power generation power of the photovoltaic power generation system is limited to 0, and the energy storage system is controlled to supply power to the load;

[0014] When the remaining power of the energy storage system is not less than a fourth set value and not greater than a third set value, controlling the energy storage system to supply power to the load and limiting the power generation power of the photovoltaic power generation system, the fourth set value being less than the third set value;

[0015] When the remaining power of the energy storage system is greater than a first set value and less than a fourth set value, controlling the energy storage system to generate power in MPPT mode, releasing the power generation limit of the photovoltaic power generation system, and the second set value is less than the fourth set value;

[0016] When the remaining power of the energy storage system is not greater than the first set value and not less than the second set value, the power generation power of the photovoltaic power generation system is limited, the diesel power generation system is controlled, and the power generation power of the diesel power generation system is controlled according to the chargeable power of the energy storage system, the power generation power of the photovoltaic system and the load power.

[0017] In an optional implementation, when the photovoltaic-storage-diesel-load integrated system switches to the first off-grid mode, the energy storage system is controlled to operate in the VSG mode, and the power generation power of the photovoltaic system is adjusted according to the remaining power of the energy storage system, further comprising:

[0018] When the remaining power of the energy storage system is less than the second set value, the energy storage system and the photovoltaic system are controlled to shut down, and the photovoltaic-storage-diesel-load integrated system is switched to the second off-grid mode.

[0019] In an optional implementation, when the photovoltaic-storage-diesel-load integrated system switches to the second off-grid mode, the diesel generator system is controlled to operate in the VSG mode, and the energy storage system is charged with the goal of not exceeding the upper limit of the load rate of the diesel generator system, including:

[0020] When the load rate of the diesel generator system is not less than a fifth set value, the diesel generator system is controlled to supply power to the load, and the diesel generator system is controlled to charge the energy storage system with the goal of not exceeding an upper limit of the load rate;

[0021] When the load rate of the diesel generator system is greater than the sixth set value and less than the fifth set value, the remaining power of the energy storage system is determined. If the remaining power of the energy storage system is less than the first set value, the diesel generator system is controlled to supply power to the load, and the diesel generator system is controlled to charge the energy storage system with the goal of not exceeding the upper limit of the load rate, and the fifth set value is greater than the sixth set value;

[0022] When the load rate of the diesel generator system is not greater than the sixth set value, the remaining power of the energy storage system is determined. If the remaining power of the energy storage system is less than the first set value, the diesel generator system is controlled to supply power to the load. At the same time, the diesel generator system is controlled to charge the energy storage system with the goal of not exceeding the upper limit of the load rate.

[0023] In an optional implementation, when the photovoltaic-storage-diesel-load integrated system switches to the second off-grid mode, the diesel generator system is controlled to operate in the VSG mode, and the energy storage system is charged with the goal of not exceeding the upper limit of the load rate of the diesel generator system, further comprising:

[0024] If the remaining power of the energy storage system is not less than the first set value, the photovoltaic storage and diesel load integrated system is switched to the first off-grid mode.

[0025] In an optional implementation, the switching condition for the photovoltaic storage diesel load integrated system to switch from the first off-grid mode to the second off-grid mode also includes:

[0026] Read the current operating mode of the diesel generator system;

[0027] When the operating mode of the diesel generator system is changed to VSG mode, the photovoltaic storage diesel load integrated system is switched from the first off-grid mode to the second off-grid mode.

[0028] In an optional implementation, the switching condition for the photovoltaic storage diesel load integrated system to switch from the second off-grid mode to the first off-grid mode also includes:

[0029] Read the current operating mode of the diesel generator system;

[0030] When the operating mode of the diesel generator system is changed to PQ mode, the photovoltaic storage diesel load integrated system is switched from the second off-grid mode to the first off-grid mode.

[0031] In a second aspect, the present invention provides an integrated photovoltaic, storage, diesel and load system, the system comprising: an energy storage system, a photovoltaic system, a diesel generation system, a load and a microgrid central control device, wherein:

[0032] The energy storage system and the photovoltaic system are each connected to the busbar via a 10kV collector line;

[0033] The load is connected to the busbar via a 10 / 0.4kV transformer;

[0034] The diesel generator system is connected to the grid at 400V;

[0035] The microgrid central control device is respectively connected to the energy storage system, the photovoltaic system, the diesel generation system and the load, so as to execute the integrated photovoltaic, storage, diesel and load multi-source collaborative control method of the first aspect or any corresponding embodiment thereof.

[0036] In an optional implementation, the system further includes: a power collection device in an energy storage area, a power collection device in a photovoltaic area, and a power collection device in a load area, wherein:

[0037] One end of the energy storage area power collection device is connected to the energy storage system, and the other end of the energy storage area power collection device is connected to the microgrid central control device. The energy storage area power collection device is used to collect the remaining power of the energy storage system and send the remaining power to the microgrid central control device;

[0038] One end of the photovoltaic area power collection device is connected to the photovoltaic system, and the other end of the photovoltaic area power collection device is connected to the microgrid central control device. The photovoltaic area power collection device is used to collect the generated power of the photovoltaic system and send the generated power to the microgrid central control device;

[0039] One end of the load area power collection device is connected to the load, and the other end of the load area power collection device is connected to the microgrid central control device. The load area power collection device is used to collect load power and send the load power to the microgrid central control device.

[0040] The present invention provides a photovoltaic storage diesel load integrated system, which realizes efficient operation and energy management of the system by adopting the above multi-source collaborative control method. It is also applicable to a variety of application scenarios, such as microgrids, emergency power supplies, and industrial applications. By adopting the above multi-source collaborative control method, the stability and economy of the system can be improved, and the development and application of integrated energy systems can be promoted. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0042] Figure 1 Schematic diagram of a photovoltaic, storage, diesel and load integrated system according to an embodiment of the present invention;

[0043] Figure 2 It is a flow chart of a method for integrated photovoltaic, storage, diesel and load multi-source collaborative control according to an embodiment of the present invention. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0045] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0046] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, it can also be the internal connection of two components, it can be a wireless connection, or it can be a wired connection. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0047] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0048] The present invention provides a photovoltaic, storage, diesel and load integrated multi-source coordinated control method, which is applied to the photovoltaic, storage, diesel and load integrated system. Figure 1As shown in the figure, the photovoltaic storage diesel load integrated system includes: energy storage system, photovoltaic system, diesel generation system and load. Among them, the energy storage system and photovoltaic system are connected to the bus with a 10kV collector line each; the load is connected to the bus with a 10 / 0.4kV transformer; the diesel generation system adopts 400V grid connection. Due to the shortcomings of the control strategy in the relevant technology in multi-source coordinated control, the system performs poorly in frequency stability, load balancing and economic operation.

[0049] To this end, according to an embodiment of the present invention, an embodiment of a multi-source collaborative control method for integrated photovoltaic, storage, diesel and load is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0050] In this embodiment, a multi-source coordinated control method for photovoltaic, storage, diesel and load integration is provided. Figure 2 is a flow chart of a multi-source coordinated control method for photovoltaic, storage, diesel and load integration according to an embodiment of the present invention. Figure 2 As shown, the process includes the following steps:

[0051] Step S1, switching the working mode of the photovoltaic-storage-diesel-load integrated system according to the remaining power of the energy storage system and the power generation power of the photovoltaic system, the working modes including a first off-grid mode and a second off-grid mode.

[0052] Specifically, the first off-grid mode is the normal operating mode of the system. In the first off-grid mode, the energy storage system acts as a voltage source and works in the VSG mode to balance the voltage and frequency of the integrated photovoltaic, storage, diesel and load system. The diesel generator mainly acts as a current source and is switched on and off as needed to inject reliable power input into the system. The second off-grid mode is the abnormal operating mode of the system. In the second off-grid mode, the diesel generator system acts as a VSG mode, and the energy management system controls the energy storage system to perform low-power power supplement and controls the photovoltaic system to limit power generation. Among them, the VSG mode is a control mode that simulates a synchronous generator. In order to ensure the stable and reliable operation of the microgrid system and reduce the system shutdown problem caused by unstable photovoltaic power generation and system power shortage, an embodiment of the present invention switches the operating mode of the integrated photovoltaic, storage, diesel and load system according to the remaining power of the energy storage system and the power generation power of the photovoltaic system.

[0053] Step S2, when the photovoltaic-storage-diesel-load integrated system switches to the first off-grid mode, the energy storage system is controlled to operate in the VSG mode, and the power generation power of the photovoltaic system is adjusted according to the remaining power of the energy storage system.

[0054] Specifically, when the photovoltaic, storage, diesel and load integrated system switches to the first off-grid mode, the energy storage system PCS operates in VSG mode, and the energy management system adjusts the output of the photovoltaic system according to the remaining power of the energy storage system, and assists the photovoltaic, storage, diesel and load integrated system to operate stably in voltage and frequency. The energy management system will, according to the battery power situation, put the diesel generation system into operation when necessary to supplement the energy storage system to prevent the system from shutting down due to low power. Among them, the working modes of each device in the photovoltaic, storage, diesel and load integrated system are as follows: the photovoltaic system operates in MPPT / power limiting mode; the energy storage system operates in VSG mode; the diesel generation system operates in cold standby mode. Among them, MPPT is maximum power point tracking, which is a technology commonly used in wind turbines and photovoltaic solar energy systems. The purpose is to obtain maximum power output in various situations.

[0055] Step S3, when the photovoltaic storage diesel load integrated system switches to the second off-grid mode, the diesel generator system is controlled to operate in VSG mode, and the energy storage system is charged with the goal of not exceeding the load rate upper limit of the diesel generator system.

[0056] Specifically, when the photovoltaic, storage, diesel and load integrated system switches to the second off-grid mode, the diesel generation system will work in the VSG mode, and the energy management system will control the energy storage to perform low-power supplementary power and control the photovoltaic power generation. Among them, the working modes of each device in the photovoltaic, storage, diesel and load integrated system are as follows: the photovoltaic system is in shutdown mode; the energy storage system works in PQ mode; the diesel generation system works in VSG mode. Among them, the PQ mode is an important control mode in the microgrid, which is mainly used to ensure that the microgrid operates synchronously with the main grid in the grid-connected mode.

[0057] The present invention provides a photovoltaic, storage, diesel and load integrated multi-source collaborative control method, which realizes efficient operation and energy management of the system by optimizing the scheduling algorithm and intelligent control method. The control method has significant advantages in frequency regulation, load balancing, economic scheduling and fault recovery, and is suitable for a variety of application scenarios, such as microgrids, emergency power supplies and industrial applications. Through reasonable design and optimization, the control method can improve the stability and economy of the system.

[0058] In an optional implementation, step S1 includes the following steps:

[0059] Step S11, when the remaining power of the energy storage system is not less than a first set value and the power generation power of the photovoltaic system is greater than the load power, the photovoltaic storage diesel-load integrated system is switched to a first off-grid mode.

[0060] Specifically, when the power generation of the photovoltaic system is greater than the load power, and the remaining power of the energy storage system is ≥15%, the photovoltaic storage diesel load integrated system will switch to the first off-grid mode. The first set value is 15% SOC. SOC is the remaining power.

[0061] Step S12, when the remaining power of the energy storage system is less than a second set value, the photovoltaic storage diesel load integrated system is switched to a second off-grid mode, and the second set value is less than the first set value.

[0062] Specifically, when the photovoltaic system fails to generate electricity or the energy storage system is short of power and cannot be started normally due to a long period of rainy days and high load users, the system will consider using the diesel generation system as a voltage source to control the energy storage system to charge at a low power level to restore the energy storage capacity. For example, when the remaining capacity of the energy storage system is less than 10% SOC, the photovoltaic system will switch to the second off-grid mode. The second setting value is 10% SOC.

[0063] In an optional implementation, step S2 includes the following steps:

[0064] Step S21, when the remaining power of the energy storage system is greater than a third set value, the power generation power of the photovoltaic power generation system is limited to 0, and the energy storage system is controlled to supply power to the load.

[0065] Step S22, when the remaining power of the energy storage system is not less than the fourth set value and not greater than the third set value, control the energy storage system to supply power to the load, limit the power generation power of the photovoltaic power generation system, and the fourth set value is less than the third set value.

[0066] Step S23, when the remaining power of the energy storage system is greater than the first set value and less than the fourth set value, the energy storage system is controlled to generate electricity in MPPT mode, the power generation limit of the photovoltaic power generation system is released, and the second set value is less than the fourth set value.

[0067] Step S24, when the remaining power of the energy storage system is not greater than the first set value and not less than the second set value, the power generation power of the photovoltaic power generation system is limited, the diesel power generation system is controlled, and the power generation power of the diesel power generation system is controlled according to the chargeable power of the energy storage system, the power generation power of the photovoltaic system and the load power.

[0068] Step S25, when the remaining power of the energy storage system is less than the second set value, the energy storage system and the photovoltaic system are controlled to shut down, and the photovoltaic storage and diesel-load integrated system is switched to the second off-grid mode.

[0069] Specifically, when the remaining power of the energy storage system is greater than 95% SOC, the energy management system limits the power generation of the photovoltaic power generation system to 0, and controls the energy storage system to supply power to the load. When 90% SOC≤the remaining power of the energy storage system≤95% SOC, the energy management system controls the energy storage system to supply power to the load, limits the power generation of the photovoltaic power generation system, and prevents excess power generation from causing imbalance within the microgrid. When 60% SOC≤the remaining power of the energy storage system<90% SOC, if the photovoltaic system is restricted from generating power, the restriction is lifted, and the photovoltaic system is controlled to generate power in MPPT mode. When 15% SOC<the remaining power of the energy storage system<60% SOC, if the photovoltaic system is restricted from generating power, the restriction is lifted, and the photovoltaic system continues to be controlled to generate power in MPPT mode. When 10% SOC≤the remaining power of the energy storage system≤15% SOC, the power generation of the photovoltaic power generation system is limited, and the input of the diesel generator system is controlled. The energy management system comprehensively controls the input of the diesel generator power according to the chargeable power of the energy storage system, the power generation power of the photovoltaic system and the load power, and replenishes the power for the energy storage system when the opportunity arises. At the same time, when the diesel generator system is started, the diesel generator system automatically determines the synchronization and closes the switch. Among them, the power generation power of the photovoltaic power generation system is limited to the maximum chargeable power of the energy storage system + the load power - the power generation power of the diesel generator system. In the first off-grid mode, the diesel generator system is mainly used to replenish the power for the energy storage system.

[0070] When the remaining power of the energy storage system is less than 10% SOC, the energy storage system and the photovoltaic system are shut down to prevent the battery power from being too low and unable to start normally; at the same time, the photovoltaic storage and diesel load integrated system is switched to the second off-grid mode. In the embodiment of the present invention, the third setting value is 95% SOC, and the fourth setting value is 90% SOC.

[0071] In an optional implementation, step S3 includes the following steps:

[0072] Step S31, when the load rate of the diesel generator system is not less than a fifth set value, the diesel generator system is controlled to supply power to the load, and the diesel generator system is controlled to charge the energy storage system with the goal of not exceeding an upper limit of the load rate.

[0073] Step S32, when the load rate of the diesel generator system is greater than the sixth set value and less than the fifth set value, determine the remaining power of the energy storage system. If the remaining power of the energy storage system is less than the first set value, control the diesel generator system to supply power to the load. At the same time, control the diesel generator system to charge the energy storage system with the goal of not exceeding the upper limit of the load rate. The fifth set value is greater than the sixth set value.

[0074] Step S33, when the load rate of the diesel generator system is not greater than the sixth set value, the remaining power of the energy storage system is determined. If the remaining power of the energy storage system is less than the first set value, the diesel generator system is controlled to supply power to the load, and at the same time, the diesel generator system is controlled to charge the energy storage system with the goal of not exceeding the upper limit of the load rate.

[0075] Specifically, when the load rate of the diesel generator system is ≥90%, the diesel generator system gives priority to supplying power to the load, and controls the diesel generator system to charge the energy storage system with the goal of not exceeding the upper limit of the load rate until it shuts down. Among them, the charging power of the energy storage system = the power generation power of the diesel generator system - the load power. When 30% < the load rate of the diesel generator system <90%, the remaining power of the energy storage system is judged. If the remaining power of the energy storage system is less than <15% SOC, the diesel generator system is controlled to supply power to the load, and at the same time, the diesel generator system is controlled to charge the energy storage system with the goal of not exceeding the upper limit of the load rate; if the remaining power of the energy storage system is ≥15% SOC, the photovoltaic storage diesel load integrated system is switched to the first off-grid mode. When the load rate of the diesel generator system is ≤30%, in order to prevent the diesel generator system from running at a lower power and causing carbon deposition and damaging the diesel generator set, the remaining power of the energy storage system is judged. If the remaining power of the energy storage system is less than <15% SOC, the diesel generator system is controlled to supply power to the load, and the diesel generator system is controlled to charge the energy storage system with the goal of not exceeding the upper limit of the load rate; if the remaining power of the energy storage system is ≥15% SOC, the photovoltaic storage diesel load integrated system is switched to the first off-grid mode. In the embodiment of the present invention, the fifth setting value is 90%, the sixth setting value is 30%, and the seventh setting value is 15%.

[0076] In an optional implementation, the switching condition for the photovoltaic storage diesel load integrated system to switch from the first off-grid mode to the second off-grid mode includes:

[0077] 1. Read the current operating mode of the diesel generator system; when the operating mode of the diesel generator system is changed to VSG mode, switch the photovoltaic storage diesel load integrated system from the first off-grid mode to the second off-grid mode.

[0078] 2. Configure the control word (first off-grid mode to second off-grid mode) on the microgrid central controller interface, and the operation and maintenance personnel can switch manually.

[0079] 3. When the remaining power of the energy storage system is less than 10% SOC, the system will start the automatic switch from the first off-grid mode to the second off-grid mode.

[0080] 4. The energy management system issues a shutdown command for the photovoltaic system.

[0081] 5. The energy management system issues an energy storage shutdown command; the entire system shuts down.

[0082] 6. After the diesel generator system mode is changed, the diesel generator system automatically starts and checks the synchronization.

[0083] 7. The energy management system issues a command to change the energy storage system operation mode from VSG to PQ;

[0084] 8. The energy management system determines the load rate of the diesel generator system, does not start the photovoltaic system, and controls the charging of the energy storage system.

[0085] 9. The second off-grid mode switch is completed.

[0086] In an optional implementation, the switching condition for the photovoltaic storage diesel load integrated system to switch from the second off-grid mode to the first off-grid mode includes:

[0087] 1. Read the current operation mode of the diesel generator system; when the operation mode of the diesel generator system changes to PQ mode, switch the photovoltaic storage diesel load integrated system from the second off-grid mode to the first off-grid mode. If the diesel generator system is not in PQ mode, change its operation mode to PQ mode. When changing to PQ mode, the diesel generator system automatically shuts down.

[0088] 2. Configure the control word on the microgrid central controller interface (switch from the second off-grid mode to the first off-grid mode), and the operation and maintenance personnel can switch manually.

[0089] 3. When the remaining power of the energy storage system is ≥15% SOC and the power generation power of the photovoltaic system is ≥load power, the system will start the automatic switching from the second off-grid mode to the first off-grid mode.

[0090] 4. The energy management system controls the shutdown of the energy storage system.

[0091] 5. The energy management system sends a VSG mode command to the energy storage converter. The battery management system performs a power supply self-check and finds no faults. The closed relay provides a high-voltage output, and the energy storage establishes the stability of the bus voltage and frequency.

[0092] 6. After the energy management system detects that the voltage and frequency are stable, it controls the photovoltaic system to start up.

[0093] 7. The first off-grid mode switch is completed.

[0094] 8. The energy management system will continue to control the photovoltaic system and the diesel generation system based on the remaining power of the energy storage system.

[0095] In one embodiment, the integrated photovoltaic, storage, diesel and load multi-source collaborative control method also adopts the VSG mode and fast response frequency modulation technology to maintain the stability of the grid frequency; an intelligent scheduling algorithm to achieve balanced load distribution; an economic scheduling model to minimize the operating cost of the system; and a fault detection and diagnosis system to promptly detect and handle system faults.

[0096] Specifically, the intelligent scheduling algorithm includes: real-time monitoring of real-time data of photovoltaic power generation systems, energy storage systems, diesel generators and loads; load forecasting, predicting future load demand based on historical data and weather forecasts; optimization scheduling, calculating the optimal output power of each power source through optimization algorithms to achieve balanced load distribution. The economic scheduling model includes: cost modeling, establishing a cost model for each power source, including fixed costs and variable costs; optimization solution, solving the optimal scheduling scheme through linear programming or nonlinear programming methods to minimize total operating costs. The fault detection and diagnosis system includes: real-time monitoring of system parameters such as voltage, current, and temperature; fault detection, detecting whether the system has a fault through data analysis and machine learning algorithms; fault diagnosis, determining the type and location of the fault, and generating a fault report; fault handling, taking corresponding handling measures according to the fault report, such as switching backup power supplies, isolating faulty equipment, etc. The present invention provides a multi-source collaborative control method for integrated photovoltaic, storage, diesel and load, which realizes efficient operation and energy management of the system through optimization scheduling algorithms and intelligent control methods.

[0097] like Figure 1 As shown, the present invention provides a photovoltaic storage diesel load integrated system, including: energy storage system, photovoltaic system, diesel generation system, load and microgrid central control device. Among them, the energy storage system and photovoltaic system are connected to the bus with a 10kV collector line respectively; the load is connected to the bus with a 10 / 0.4kV transformer; the diesel generation system adopts 400V grid connection; the microgrid central control device is respectively connected to the energy storage system, photovoltaic system, diesel generation system and load, so as to execute the photovoltaic storage diesel load integrated multi-source coordinated control method in the above embodiment.

[0098] Specifically, the energy storage system configuration is as follows: 2.5MW / 5MWh energy storage, 5MWh container energy storage, single branch output; the photovoltaic system configuration is as follows: 320kW*9 photovoltaic inverters; the diesel generator system configuration is as follows: 260kW*2; the load is mainly for domestic electricity, with a peak power of 900kW. An energy management system can be set up inside the microgrid central control device to monitor and intelligently control energy distribution in real time, so as to achieve efficient management and optimal configuration of energy.

[0099] As an independently controllable microgrid system, the integrated photovoltaic, storage, diesel and load system connects distributed photovoltaic power generation, diesel generators, energy storage systems, and household loads to achieve energy balance control of multiple distributed energy sources and continuous and uninterrupted power supply to loads.

[0100] In an optional embodiment, if Figure 1As shown, the photovoltaic storage diesel load integrated system also includes: a power collection device in the energy storage area, a power collection device in the photovoltaic area, and a power collection device in the load area. Among them, one end of the power collection device in the energy storage area is connected to the energy storage system, and the other end of the power collection device in the energy storage area is connected to the microgrid central control device. The power collection device in the energy storage area is used to collect the remaining power of the energy storage system and send the remaining power to the microgrid central control device. One end of the power collection device in the photovoltaic area is connected to the photovoltaic system, and the other end of the power collection device in the photovoltaic area is connected to the microgrid central control device. The power collection device in the photovoltaic area is used to collect the generated power of the photovoltaic system and send the generated power to the microgrid central control device. One end of the power collection device in the load area is connected to the load, and the other end of the power collection device in the load area is connected to the microgrid central control device. The power collection device in the load area is used to collect the load power and send the load power to the microgrid central control device.

[0101] Specifically, the power collection device in the energy storage area sends the collected bus status and the remaining power of the energy storage system to the microgrid central control device; the power collection device in the photovoltaic area sends the collected bus status and the power generation power of the photovoltaic system to the microgrid central control device; the power collection device in the load area sends the collected bus status and load power to the microgrid central control device. The microgrid central control device makes energy management decisions based on the above information.

[0102] The present invention provides a photovoltaic storage diesel load integrated system, which realizes efficient operation and energy management of the system by adopting the above multi-source collaborative control method. It is also applicable to a variety of application scenarios, such as microgrids, emergency power supplies, and industrial applications. By adopting the above multi-source collaborative control method, the stability and economy of the system can be improved, and the development and application of integrated energy systems can be promoted.

[0103] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A photovoltaic, storage, diesel and load integrated multi-source coordinated control method, characterized in that: Applied to a photovoltaic, storage, diesel and load integrated system, the method comprises: Switching the working mode of the photovoltaic energy storage and diesel load integrated system according to the remaining power of the energy storage system and the power generation power of the photovoltaic system, wherein the working mode includes a first off-grid mode and a second off-grid mode; When the photovoltaic-storage-diesel-load integrated system switches to the first off-grid mode, the energy storage system is controlled to operate in the VSG mode, and the power generation power of the photovoltaic system is adjusted according to the remaining power of the energy storage system; When the integrated solar-storage-diesel-load system switches to the second off-grid mode, the diesel-generator system is controlled to operate in VSG mode, and the energy storage system is charged with the goal of not exceeding the load rate upper limit of the diesel-generator system.

2. The integrated photovoltaic, storage, diesel and load multi-source coordinated control method according to claim 1 is characterized in that: The working mode of the photovoltaic-storage-diesel-load integrated system is switched according to the remaining power of the energy storage system and the power generation power of the photovoltaic system, including: When the remaining power of the energy storage system is not less than the first set value and the power generation power of the photovoltaic system is greater than the load power, the photovoltaic storage diesel-load integrated system is switched to the first off-grid mode; When the remaining power of the energy storage system is less than a second set value, the photovoltaic storage and diesel load integrated system is switched to a second off-grid mode, and the second set value is less than the first set value.

3. The integrated photovoltaic, storage, diesel and load multi-source coordinated control method according to claim 2 is characterized in that: When the photovoltaic-storage-diesel-load integrated system switches to the first off-grid mode, the energy storage system is controlled to operate in VSG mode, and the power generation power of the photovoltaic system is adjusted according to the remaining power of the energy storage system, including: When the remaining power of the energy storage system is greater than a third set value, the power generation power of the photovoltaic power generation system is limited to 0, and the energy storage system is controlled to supply power to the load; When the remaining power of the energy storage system is not less than a fourth set value and not greater than a third set value, controlling the energy storage system to supply power to the load and limiting the power generation power of the photovoltaic power generation system, the fourth set value being less than the third set value; When the remaining power of the energy storage system is greater than a first set value and less than a fourth set value, controlling the energy storage system to generate power in MPPT mode, releasing the power generation limit of the photovoltaic power generation system, and the second set value is less than the fourth set value; When the remaining power of the energy storage system is not greater than the first set value and not less than the second set value, the power generation power of the photovoltaic power generation system is limited, the diesel power generation system is controlled, and the power generation power of the diesel power generation system is controlled according to the chargeable power of the energy storage system, the power generation power of the photovoltaic system and the load power.

4. The integrated photovoltaic, storage, diesel and load multi-source coordinated control method according to claim 3 is characterized in that: When the photovoltaic storage diesel-load integrated system switches to the first off-grid mode, the energy storage system is controlled to operate in the VSG mode, and the power generation power of the photovoltaic system is adjusted according to the remaining power of the energy storage system, which also includes: When the remaining power of the energy storage system is less than the second set value, the energy storage system and the photovoltaic system are controlled to shut down, and the photovoltaic-storage-diesel-load integrated system is switched to the second off-grid mode.

5. The integrated photovoltaic, storage, diesel and load multi-source coordinated control method according to claim 2 is characterized in that: When the solar-storage-diesel-load integrated system switches to the second off-grid mode, the diesel generator system is controlled to operate in VSG mode, and the energy storage system is charged with the goal of not exceeding the load rate upper limit of the diesel generator system, including: When the load rate of the diesel generator system is not less than a fifth set value, the diesel generator system is controlled to supply power to the load, and the diesel generator system is controlled to charge the energy storage system with the goal of not exceeding an upper limit of the load rate; When the load rate of the diesel generator system is greater than the sixth set value and less than the fifth set value, the remaining power of the energy storage system is determined. If the remaining power of the energy storage system is less than the first set value, the diesel generator system is controlled to supply power to the load, and the diesel generator system is controlled to charge the energy storage system with the goal of not exceeding the upper limit of the load rate, and the fifth set value is greater than the sixth set value; When the load rate of the diesel generator system is not greater than the sixth set value, the remaining power of the energy storage system is determined. If the remaining power of the energy storage system is less than the first set value, the diesel generator system is controlled to supply power to the load. At the same time, the diesel generator system is controlled to charge the energy storage system with the goal of not exceeding the upper limit of the load rate.

6. The integrated photovoltaic, storage, diesel and load multi-source coordinated control method according to claim 5 is characterized in that: When the solar-storage-diesel-load integrated system switches to the second off-grid mode, the diesel generator system is controlled to operate in VSG mode, and the energy storage system is charged with the goal of not exceeding the load rate upper limit of the diesel generator system, which also includes: If the remaining power of the energy storage system is not less than the first set value, the photovoltaic storage and diesel load integrated system is switched to the first off-grid mode.

7. The integrated photovoltaic, storage, diesel and load multi-source coordinated control method according to claim 1 is characterized in that: The switching conditions for the photovoltaic storage diesel-load integrated system to switch from the first off-grid mode to the second off-grid mode also include: Read the current operating mode of the diesel generator system; When the operating mode of the diesel generator system is changed to VSG mode, the photovoltaic storage diesel load integrated system is switched from the first off-grid mode to the second off-grid mode.

8. The integrated photovoltaic, storage, diesel and load multi-source coordinated control method according to claim 1 is characterized in that: The switching conditions for the photovoltaic storage diesel-load integrated system to switch from the second off-grid mode to the first off-grid mode also include: Read the current operating mode of the diesel generator system; When the operating mode of the diesel generator system is changed to PQ mode, the photovoltaic storage diesel load integrated system is switched from the second off-grid mode to the first off-grid mode.

9. A photovoltaic, storage, diesel and load integrated system, characterized in that: The system includes: energy storage system, photovoltaic system, diesel generation system, load and microgrid central control device, wherein: The energy storage system and the photovoltaic system are each connected to the busbar via a 10kV collector line; The load is connected to the busbar via a 10 / 0.4kV transformer; The diesel generator system is connected to the grid at 400V; The microgrid central control device is respectively connected to the energy storage system, the photovoltaic system, the diesel generation system and the load, so as to execute the integrated photovoltaic, storage, diesel and load multi-source collaborative control method according to any one of claims 1 to 8.

10. The photovoltaic, storage, diesel and load integrated system according to claim 9, characterized in that: The system also includes: a power collection device in the energy storage area, a power collection device in the photovoltaic area, and a power collection device in the load area, wherein: One end of the energy storage area power collection device is connected to the energy storage system, and the other end of the energy storage area power collection device is connected to the microgrid central control device. The energy storage area power collection device is used to collect the remaining power of the energy storage system and send the remaining power to the microgrid central control device; One end of the photovoltaic area power collection device is connected to the photovoltaic system, and the other end of the photovoltaic area power collection device is connected to the microgrid central control device. The photovoltaic area power collection device is used to collect the generated power of the photovoltaic system and send the generated power to the microgrid central control device; One end of the load area power collection device is connected to the load, and the other end of the load area power collection device is connected to the microgrid central control device. The load area power collection device is used to collect load power and send the load power to the microgrid central control device.

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