Control method and system for connecting energy storage inverter into diesel generator and power grid in parallel

Abstract

The invention provides a control method and system for connecting an energy storage inverter into a diesel generator and a power grid in parallel, and belongs to the technical field of electric energy dispatching. The control method for connecting the energy storage inverters into the diesel generator and the power grid in parallel comprises the following steps of S1, arranging the multiple energy storage inverters in parallel; s2, all the energy storage inverters are controlled to be started; s3, respectively acquiring real-time residual electric quantity of all the batteries; s4, when the real-time residual electric quantity of the battery corresponding to at least one energy storage inverter is smaller than a first preset value, the energy storage inverters are controlled to stop discharging, and when a first preset condition is met, the diesel generator is controlled to be started; and S5, when the real-time residual electric quantities of all the energy storage inverters are greater than a second preset value and meet a second preset condition, controlling the diesel generator to be turned off and controlling all the energy storage inverters to be turned on. Start and stop of the diesel generator are reasonably controlled, and the diesel generator and the battery are effectively utilized.

Description

Technical Field

[0001] The present invention relates to the technical field of electric energy dispatching, and in particular to a control method and system for connecting an energy storage inverter in parallel to a diesel generator and a power grid. Background Art

[0002] In the existing energy dispatching of smart microgrids, after the diesel generator is started, the mode of the energy storage inverter is switched from V / F mode to PQ mode, the working status of the energy storage system and the online status of the smart microgrid and the power grid are obtained, and the parameters sent by the EMS are adjusted based on the working status of the energy storage system and the online status of the smart microgrid and the power grid. Energy dispatching is achieved based on the adjustment of the parameters sent by the EMS. After the diesel generator is started, the mode of the energy storage inverter is PQ mode, and the power of the battery corresponding to the energy storage inverter will continue to decrease. The continuous operation of the energy storage inverter is not conducive to the diesel generator to stably charge the battery corresponding to the energy storage inverter. At the same time, many states are obtained during the energy dispatching process, and the energy dispatching method is relatively complicated. Summary of the invention

[0003] In order to solve the above problems, an embodiment of the present application provides a control method and system for connecting an energy storage inverter in parallel to a diesel generator and a power grid.

[0004] In a first aspect, the present application provides a control method for connecting an energy storage inverter in parallel to a diesel generator and a power grid, comprising the following steps: S1: multiple energy storage inverters are connected in parallel, and each energy storage inverter is connected to a corresponding battery; S2: Control all energy storage inverters to start, so that all energy storage inverters can supply power to loads off-grid; S3: Obtain the real-time remaining power of all batteries respectively; S4: when the real-time remaining power of the battery corresponding to at least one energy storage inverter is less than a first preset value, control the energy storage inverter to stop discharging, and control the diesel generator to start when the first preset condition is met, so that the diesel generator supplies power to the load and charges the battery corresponding to the energy storage inverter; S5: When the real-time remaining power of all energy storage inverters is greater than a second preset value and a second preset condition is met, the diesel generator is controlled to shut down and all energy storage inverters are started, so that all energy storage inverters are off-grid to supply power to the load, and the second preset value is greater than the first preset value.

[0005] Preferably, in step S4, when the first preset condition is met, controlling the diesel generator to start so that the diesel generator supplies power to the load and charges the battery corresponding to the part of the energy storage inverter respectively specifically includes: Determining whether the remaining energy storage inverter can support the load operation to obtain first determination information; If the first judgment information is that the remaining energy storage inverter can support the load operation, then the part of the energy storage inverter is controlled to stop discharging and the other energy storage inverters continue to operate. If the first judgment information is that the remaining energy storage inverter cannot support the load operation, then the diesel generator is controlled to start, so that the diesel generator supplies power to the load and charges the battery corresponding to the part of the energy storage inverter.

[0006] Preferably, judging whether the remaining energy storage inverter can support the load operation to obtain the first determination information specifically includes: Respectively obtaining the load power required for load operation and the first preset power output by each remaining energy storage inverter; Calculating and acquiring a first total power of the remaining energy storage inverters according to a first preset power output by each remaining energy storage inverter; If the first total power is not less than the load power, the first judgment information is that the remaining energy storage inverter can support the load operation. If the first total power is less than the load power, the first judgment information is that the remaining energy storage inverter cannot support the load operation.

[0007] Preferably, in step S5, when the real-time remaining power of all energy storage inverters is greater than the second preset value and the second preset condition is met, controlling the diesel generator to shut down and all energy storage inverters to start specifically includes: When the real-time remaining power of all energy storage inverters is greater than the second preset value, determining whether all energy storage inverters can support load operation to obtain second determination information; If the second judgment information is that all energy storage inverters cannot support the load operation, the diesel generator is controlled to continue running. If the second judgment information is that all energy storage inverters can support the load operation, the diesel generator is controlled to be shut down and all energy storage inverters are started, so that all energy storage inverters are off-grid to supply power to the load.

[0008] Preferably, the diesel generator respectively supplies power to the load and charges the battery corresponding to the part of the energy storage inverter, including: obtaining the corresponding relationship between the charging power of the diesel generator for charging the battery and the remaining power of the battery, obtaining the real-time charging power of the battery corresponding to the energy storage inverter based on the corresponding relationship and the real-time remaining power of the battery corresponding to the energy storage inverter, and the diesel generator charges the battery corresponding to the energy storage inverter based on the real-time charging power.

[0009] In a second aspect, an embodiment of the present application provides a control system in which an energy storage inverter is connected in parallel to a diesel generator and a power grid, including a determination control module, a collection module, a diesel generator, multiple energy storage inverters, and multiple batteries; A plurality of the energy storage inverters are arranged in parallel, and each of the energy storage inverters is respectively connected to a corresponding battery; The acquisition module is used to obtain the real-time remaining power of all batteries respectively; The determination control module is used to control the part of the energy storage inverters to stop discharging when the real-time remaining power of the battery corresponding to at least one energy storage inverter is less than a first preset value, and to control the diesel generator to start when the first preset condition is met, so that the diesel generator supplies power to the load and charges the battery corresponding to the part of the energy storage inverter respectively; when the real-time remaining power of all the energy storage inverters is greater than a second preset value and the second preset condition is met, control the diesel generator to shut down and all the energy storage inverters to start, so that all the energy storage inverters are off-grid to supply power to the load, and the second preset value is greater than the first preset value.

[0010] Preferably, the determination control module includes a first control unit and a first determination unit; The first control unit is used to control the energy storage inverters to stop discharging when the real-time remaining power of the battery corresponding to at least one energy storage inverter is less than a first preset value; The first determination unit is used to determine whether the remaining energy storage inverter can support the load operation to obtain first determination information; The first control unit is used to control the part of the energy storage inverter to stop discharging and the other energy storage inverters to continue operating if the first judgment information is that the remaining energy storage inverter can support the load operation; if the first judgment information is that the remaining energy storage inverter cannot support the load operation, control the diesel generator to start, so that the diesel generator supplies power to the load and charges the battery corresponding to the part of the energy storage inverter.

[0011] Preferably, the first determination unit determines whether the remaining energy storage inverter can support the load operation to obtain the first determination information specifically includes: respectively obtaining the load power required for the load operation and the first preset power output by each remaining energy storage inverter; Calculating and acquiring a first total power of the remaining energy storage inverters according to a first preset power output by each remaining energy storage inverter; If the first total power is not less than the load power, the first judgment information is that the remaining energy storage inverter can support the load operation. If the first total power is less than the load power, the first judgment information is that the remaining energy storage inverter cannot support the load operation.

[0012] Preferably, the first determination unit also includes: when the real-time remaining power of all energy storage inverters is greater than a second preset value, determining whether all energy storage inverters can support the load operation to obtain second determination information; the first control unit also includes: if the second determination information is that all energy storage inverters cannot support the load operation, controlling the diesel generator to continue to run; if the second determination information is that all energy storage inverters can support the load operation, controlling the diesel generator to shut down and all energy storage inverters to start, so that all energy storage inverters are off-grid to supply power to the load.

[0013] Preferably, the determination control module includes, when the diesel generator supplies power to the load and charges the battery corresponding to the part of the energy storage inverter respectively: obtaining the corresponding relationship between the charging power of the diesel generator for charging the battery and the remaining power of the battery, obtaining the real-time charging power of the battery corresponding to the energy storage inverter based on the corresponding relationship and the real-time remaining power of the battery corresponding to the energy storage inverter, and charging the battery corresponding to the energy storage inverter by the diesel generator based on the real-time charging power.

[0014] The beneficial effects of the present invention are as follows: when some energy storage inverters stop and the first preset condition is met, the diesel generator is controlled to start, so that the diesel generator supplies power to the load and charges the battery corresponding to the part of the energy storage inverter respectively; when the real-time remaining power of all energy storage inverters is greater than the second preset value and the second preset condition is met, the diesel generator is controlled to be shut down and all energy storage inverters are started, so that all energy storage inverters are off-grid to supply power to the load, the start and stop of the diesel generator is reasonably controlled, the diesel generator and the battery are effectively utilized, and an effective method is provided for preventing the diesel generator from frequently starting and stopping and ensuring the power supply to the load. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 A flow chart of a control method for connecting an energy storage inverter in parallel to a diesel generator and a power grid provided in an embodiment of the present application; Figure 2 A schematic diagram of the structure of a control system in which an energy storage inverter is connected in parallel to a diesel generator and a power grid provided in an embodiment of the present application. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

[0018] In the following introduction, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance. The following introduction provides multiple embodiments of the present application, and different embodiments can be replaced or combined, so the present application can also be considered to include all possible combinations of the same and / or different embodiments recorded. Therefore, if one embodiment includes features A, B, and C, and another embodiment includes features B and D, then the present application should also be considered to include embodiments containing one or more of all other possible combinations of A, B, C, and D, although the embodiment may not be clearly recorded in the following text.

[0019] The following description provides examples and does not limit the scope, applicability or examples set forth in the claims. Changes may be made to the functions and arrangements of the elements described without departing from the scope of the present application. Various processes or components may be appropriately omitted, substituted or added to each example. For example, the described method may be performed in an order different from the order described, and various steps may be added, omitted or combined. In addition, features described in some examples may be combined in other examples.

[0020] See also Figure 1 . Figure 1 1 is a flow chart of a control method for connecting an energy storage inverter in parallel to a diesel generator and a power grid provided in an embodiment of the present application. In an embodiment of the present application, the method comprises the following steps: S1: multiple energy storage inverters are connected in parallel, and each energy storage inverter is connected to a corresponding battery; S2: Control all energy storage inverters to start, so that all energy storage inverters can supply power to loads off-grid; S3: Obtain the real-time remaining power of all batteries respectively; S4: when the real-time remaining power of the battery corresponding to at least one energy storage inverter is less than a first preset value, control the energy storage inverter to stop discharging, and control the diesel generator to start when the first preset condition is met, so that the diesel generator supplies power to the load and charges the battery corresponding to the energy storage inverter; S5: When the real-time remaining power of all energy storage inverters is greater than a second preset value and a second preset condition is met, the diesel generator is controlled to shut down and all energy storage inverters are started, so that all energy storage inverters are off-grid to supply power to the load, and the second preset value is greater than the first preset value.

[0021] In the embodiment of the present application, the energy storage inverter can generally control the start and stop of the diesel generator according to the battery power. There are multiple energy storage inverters, each inverter is connected to its own battery, and the battery power connected to each energy storage inverter is different, so it is necessary to comprehensively consider the battery power of each inverter to start and stop the generator. The present application proposes innovations in energy scheduling after the diesel generator is started, and makes reasonable control over the start and stop of the diesel generator and the distribution of charging power.

[0022] In the embodiment of the present application, two thresholds are preset, namely a first preset value and a second preset value, and the first preset value is less than the second preset value. When multiple energy storage inverters are connected in parallel, energy storage inverters in a non-operating state are first excluded and are not considered when making a diesel generator start-up and shutdown judgment.

[0023] In one possible implementation mode, in step S4, when the first preset condition is met, controlling the diesel generator to start so that the diesel generator supplies power to the load and charges the battery corresponding to the part of the energy storage inverter respectively specifically includes: Determining whether the remaining energy storage inverter can support the load operation to obtain first determination information; If the first judgment information is that the remaining energy storage inverter can support the load operation, then the part of the energy storage inverter is controlled to stop discharging and the other energy storage inverters continue to operate. If the first judgment information is that the remaining energy storage inverter cannot support the load operation, then the diesel generator is controlled to start, so that the diesel generator supplies power to the load and charges the battery corresponding to the part of the energy storage inverter.

[0024] In an embodiment of the present application, when the diesel generator is turned off, the energy storage inverter runs off-grid to supply power to the load, and the battery power continues to decrease. When the remaining power of an inverter is lower than a first preset value, it is determined whether the remaining energy storage inverter can support the load if the energy storage inverter stops discharging.

[0025] In one possible implementation, determining whether the remaining energy storage inverter can support the load operation to obtain the first determination information specifically includes: Respectively obtaining the load power required for load operation and the first preset power output by each remaining energy storage inverter; Calculating and acquiring a first total power of the remaining energy storage inverters according to a first preset power output by each remaining energy storage inverter; If the first total power is not less than the load power, the first judgment information is that the remaining energy storage inverter can support the load operation. If the first total power is less than the load power, the first judgment information is that the remaining energy storage inverter cannot support the load operation.

[0026] In an embodiment of the present application, the first preset power may be the maximum power output by the energy storage inverter. The load power of the load and the maximum power output by each energy storage inverter are obtained, and the maximum power output by the remaining energy storage inverters is added to obtain the maximum load capacity of the remaining energy storage inverters, that is, the first total power of the remaining energy storage inverters is obtained. If the maximum load capacity of the remaining energy storage inverter is less than the load power, it is judged that the remaining energy storage inverter cannot support the load, and the first judgment information is that the remaining energy storage inverter cannot support the load operation. If the maximum load capacity of the remaining energy storage inverter is not less than the load power, it is judged that the remaining energy storage inverter can support the load, and the first judgment information is that the remaining energy storage inverter can support the load operation.

[0027] In one possible implementation, in step S5, when the real-time remaining power of all energy storage inverters is greater than the second preset value and the second preset condition is met, controlling the diesel generator to shut down and all energy storage inverters to start specifically includes: When the real-time remaining power of all energy storage inverters is greater than the second preset value, determining whether all energy storage inverters can support load operation to obtain second determination information; If the second judgment information is that all energy storage inverters cannot support the load operation, the diesel generator is controlled to continue running. If the second judgment information is that all energy storage inverters can support the load operation, the diesel generator is controlled to be shut down and all energy storage inverters are started, so that all energy storage inverters are off-grid to supply power to the load.

[0028] In an embodiment of the present application, after the diesel generator is started, the diesel generator charges the corresponding part of the energy storage inverters. When the battery power of all inverters is greater than the second preset value, it is determined whether all inverters can support the load. If so, the diesel generator is turned off, and all the energy storage inverters are operated off-grid with load; if not, the diesel generator continues to run. At this time, only the diesel generator can supply power to the load. It is necessary to prevent the diesel generator from suddenly stopping due to a fault. Therefore, the battery corresponding to the energy storage inverter is not discharged at this time, and the battery power is retained, so that the battery corresponding to the energy storage inverter can continue to supply power to the load after the diesel generator stops due to a fault.

[0029] In the embodiment of the present application, judging whether all energy storage inverters can support load operation to obtain the second determination information specifically includes: respectively obtaining the load power required for load operation and the first preset power output by all energy storage inverters; Calculate and obtain a second total power of all energy storage inverters according to a first preset power output by each energy storage inverter; If the second total power is not less than the load power, the second determination information is that all energy storage inverters can support the load operation; if the second total power is less than the load power, the second determination information is that the remaining energy storage inverters cannot support the load operation.

[0030] In an embodiment of the present application, when the diesel generator is started, the diesel generator charges part of the energy storage inverter and controls the sum of the charging power and the load power to the battery not to exceed a third preset value. The third preset value is related to the parameters of the diesel generator. The third preset value is generally the maximum load power that the diesel generator can operate for a long time.

[0031] In one possible implementation, the diesel generator respectively supplies power to the load and charges the battery corresponding to the part of the energy storage inverter, including: obtaining the correspondence between the charging power of the diesel generator for charging the battery and the remaining power of the battery, obtaining the real-time charging power of the battery corresponding to the energy storage inverter based on the correspondence and the real-time remaining power of the battery corresponding to the energy storage inverter, and charging the battery corresponding to the energy storage inverter by the diesel generator based on the real-time charging power.

[0032] In the embodiment of the present application, the corresponding relationship between the charging power of the diesel generator to charge the battery and the remaining power of the battery can be an inverse relationship, that is, the charging power is inversely proportional to the remaining power of the battery, and the smaller the remaining power, the greater the charging power. When the diesel generator is started, the diesel generator charges the battery corresponding to the energy storage inverter, and the charging power of each battery should be reasonably allocated according to the different remaining power of the battery.

[0033] In the embodiment of the present application, the present application makes a reasonable control strategy for the start and stop of the diesel generator and the allocation of charging power to the battery (hereinafter referred to as "diesel generator start and stop strategy"). The diesel generator start and stop strategy effectively utilizes the diesel generator and the battery, and provides an effective method for preventing the frequent start and stop of the diesel generator and ensuring the power supply of the load; the battery charging power allocation strategy when the diesel generator is running provides beneficial effects in terms of accelerating the charging speed and improving the battery life.

[0034] The following will be combined with the attached Figure 2 , a control system for connecting an energy storage inverter in parallel to a diesel generator and a power grid provided in an embodiment of the present application is described in detail. Figure 2 A control system in which an energy storage inverter is connected in parallel to a diesel generator and a power grid is used to implement the present application Figure 1 For the convenience of explanation, only the part related to the embodiment of the present application is shown. For the specific technical details not disclosed, please refer to the present application. Figure 1 The embodiment shown.

[0035] See also Figure 2 , Figure 2 1 is a schematic diagram of a control system in which an energy storage inverter is connected in parallel to a diesel generator and a power grid according to an embodiment of the present application. Figure 2 As shown, the device includes a determination control module 201, a collection module 202, a diesel generator 203, a plurality of energy storage inverters 204, and a plurality of batteries 205; A plurality of the energy storage inverters 204 are arranged in parallel, and each of the energy storage inverters 204 is respectively connected to a corresponding battery 205; The acquisition module 202 is used to obtain the real-time remaining power of all batteries 205 respectively; The determination control module 201 is used to control the part of the energy storage inverters 204 to stop discharging when the real-time remaining power of the battery 205 corresponding to at least one energy storage inverter 204 is less than a first preset value, and to control the diesel generator 203 to start when the first preset condition is met, so that the diesel generator 203 supplies power to the load and charges the battery 205 corresponding to the part of the energy storage inverter 204 respectively; when the real-time remaining power of all the energy storage inverters 204 is greater than a second preset value and the second preset condition is met, control the diesel generator 203 to shut down and all the energy storage inverters 204 to start, so that all the energy storage inverters 204 supply power to the load off-grid, and the second preset value is greater than the first preset value.

[0036] In one possible implementation, the determination control module 201 includes a first control unit and a first determination unit; The first control unit is used to control the energy storage inverter 204 to stop discharging when the real-time remaining power of the battery 205 corresponding to at least one energy storage inverter 204 is less than a first preset value; The first determination unit is used to determine whether the remaining energy storage inverter 204 can support the load operation to obtain first determination information; The first control unit is used to control the part of the energy storage inverter 204 to stop discharging and the other energy storage inverters 204 to continue operating if the first judgment information is that the remaining energy storage inverter 204 can support the load operation; if the first judgment information is that the remaining energy storage inverter 204 cannot support the load operation, control the diesel generator 203 to start, so that the diesel generator 203 respectively supplies power to the load and charges the battery 205 corresponding to the part of the energy storage inverter 204.

[0037] In an embodiment of the present application, when the diesel generator 203 is turned off, the energy storage inverter 204 operates off-grid to supply power to the load, and the power of the battery 205 continues to decrease. When the remaining power of an inverter is lower than a first preset value, it is determined whether the remaining energy storage inverter 204 can support the load if the energy storage inverter 204 stops discharging.

[0038] In one possible implementation, the first determination unit determines whether the remaining energy storage inverter 204 can support the load operation to obtain the first determination information specifically includes: respectively obtaining the load power required for the load operation and the first preset power output by each remaining energy storage inverter 204; Calculating and acquiring a first total power of the remaining energy storage inverters 204 according to the first preset power output by each remaining energy storage inverter 204; If the first total power is not less than the load power, the first judgment information is that the remaining energy storage inverter 204 can support the load operation. If the first total power is less than the load power, the first judgment information is that the remaining energy storage inverter 204 cannot support the load operation.

[0039] In an embodiment of the present application, the first preset power may be the maximum power output by the energy storage inverter 204. The load power of the load and the maximum power output by each energy storage inverter 204 are obtained. The maximum power output by the remaining energy storage inverters 204 is added to obtain the maximum load capacity of the remaining energy storage inverters 204, that is, the first total power of the remaining energy storage inverters 204 is obtained. If the maximum load capacity of the remaining energy storage inverter 204 is less than the load power, it is determined that the remaining energy storage inverter 204 cannot support the load, and the first judgment information is that the remaining energy storage inverter 204 cannot support the load operation. If the maximum load capacity of the remaining energy storage inverter 204 is not less than the load power, it is determined that the remaining energy storage inverter 204 can support the load, and the first judgment information is that the remaining energy storage inverter 204 can support the load operation.

[0040] In one embodiment, the first determination unit also includes: when the real-time remaining power of all energy storage inverters 204 is greater than a second preset value, determining whether all energy storage inverters 204 can support the load operation to obtain second determination information; the first control unit also includes: if the second determination information is that all energy storage inverters 204 cannot support the load operation, controlling the diesel generator 203 to continue running; if the second determination information is that all energy storage inverters 204 can support the load operation, controlling the diesel generator 203 to shut down and all energy storage inverters 204 to start, so that all energy storage inverters 204 are off-grid to supply power to the load.

[0041] In the embodiment of the present application, after the diesel generator 203 is started, the diesel generator 203 charges the corresponding part of the energy storage inverter 204. When the power of the battery 205 of all the inverters is greater than the second preset value, it is determined whether all the inverters can support the load. If so, the diesel generator 203 is turned off, and all the energy storage inverters 204 are operated off-grid with load; if not, the diesel generator 203 continues to run. At this time, only the diesel generator 203 can supply power to the load. It is necessary to prevent the diesel generator 203 from suddenly stopping due to a fault. Therefore, the battery 205 corresponding to the energy storage inverter 204 is not discharged at this time, and the power of the battery 205 is retained, so that the battery 205 corresponding to the energy storage inverter 204 can continue to supply power to the load after the diesel generator 203 stops due to a fault.

[0042] In an embodiment of the present application, when the diesel generator 203 is started, the diesel generator 203 charges part of the energy storage inverter 204, and controls the sum of the charging power and the load power supplied to the battery 205 not to exceed a third preset value, which is related to the parameters of the diesel generator 203. The third preset value is generally the maximum load power at which the diesel generator 203 can operate for a long time.

[0043] In one possible implementation, the determination control module 201 includes the following steps in which the diesel generator 203 supplies power to the load and charges the battery 205 corresponding to the energy storage inverter 204: obtaining the corresponding relationship between the charging power of the diesel generator 203 for charging the battery 205 and the remaining power of the battery 205, obtaining the real-time charging power of the battery 205 corresponding to the energy storage inverter 204 based on the corresponding relationship and the real-time remaining power of the battery 205 corresponding to the energy storage inverter 204, and charging the battery 205 corresponding to the energy storage inverter 204 based on the real-time charging power.

[0044] In the embodiment of the present application, the corresponding relationship between the charging power of the diesel generator 203 to charge the battery 205 and the remaining power of the battery 205 can be an inverse relationship, that is, the charging power is inversely proportional to the remaining power of the battery 205, and the smaller the remaining power, the greater the charging power. When the diesel generator 203 is started, the diesel generator 203 charges the battery 205 corresponding to the energy storage inverter 204, and the charging power of each battery 205 should be reasonably allocated according to the different remaining power of the battery 205.

[0045] In the embodiment of the present application, the present application makes a reasonable control strategy for the start and stop of the diesel generator 203 and the allocation of charging power to the battery 205. The diesel generator start and stop strategy effectively utilizes the diesel generator 203 and the battery 205, and provides an effective method for preventing the frequent start and stop of the diesel generator 203 and ensuring the power supply of the load; the battery 205 charging power allocation strategy when the diesel generator 203 is running provides beneficial effects in accelerating the charging speed, improving the life of the battery 205, etc.

[0046] Those skilled in the art can clearly understand that the technical solutions of the embodiments of the present application can be implemented with the help of software and / or hardware. The "unit", "module" and "part" in this specification refer to software and / or hardware that can independently complete or cooperate with other components to complete specific functions, where the hardware can be, for example, a field programmable gate array (FPGA), an integrated circuit (IC), etc.

[0047] Each processing unit and / or module of the embodiments of the present application may be implemented by an analog circuit that implements the functions described in the embodiments of the present application, or may be implemented by software that executes the functions described in the embodiments of the present application.

[0048] It should be noted that, for the aforementioned method embodiments, for the sake of simplicity, they are all expressed as a series of action combinations, but those skilled in the art should be aware that the present application is not limited by the described order of actions, because according to the present application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present application.

[0049] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0050] In the several embodiments provided in the present application, it should be understood that the disclosed devices can be implemented in other ways. For example, the device embodiments described above are only schematic, such as the division of the units, which is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some service interfaces, and the indirect coupling or communication connection of devices or units can be electrical or other forms.

[0051] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0052] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0053] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable memory. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a memory, including a number of instructions to enable a computer device (which can be a personal computer, server or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned memory includes: U disk, read-only memory (ROM), random access memory (RAM), mobile hard disk, disk or optical disk and other media that can store program codes.

[0054] A person skilled in the art may understand that all or part of the steps in the various methods of the above embodiments may be completed by entering a program to instruct related hardware. The program may be stored in a computer-readable memory, and the memory may include: a flash drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, etc.

[0055] The above is only an exemplary embodiment of the present disclosure, and the scope of the present disclosure cannot be limited thereto. That is, any equivalent changes and modifications made according to the teachings of the present disclosure are still within the scope of the present disclosure. After considering the specification and practicing the disclosure here, those skilled in the art will easily think of the implementation scheme of the present disclosure. This application is intended to cover any modification, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary technical means in the technical field not recorded in the present disclosure. The description and examples are regarded as exemplary only, and the scope and spirit of the present disclosure are defined by the claims.

Claims

1. A control method for connecting an energy storage inverter in parallel to a diesel generator and a power grid, characterized in that: The steps include: S1: multiple energy storage inverters are connected in parallel, and each energy storage inverter is connected to a corresponding battery; S2: Control all energy storage inverters to start, so that all energy storage inverters can supply power to loads off-grid; S3: Obtain the real-time remaining power of all batteries respectively; S4: when the real-time remaining power of the battery corresponding to at least one energy storage inverter is less than a first preset value, control the energy storage inverter to stop discharging, and control the diesel generator to start when the first preset condition is met, so that the diesel generator supplies power to the load and charges the battery corresponding to the energy storage inverter; S5: When the real-time remaining power of all energy storage inverters is greater than a second preset value and a second preset condition is met, the diesel generator is controlled to shut down and all energy storage inverters are started, so that all energy storage inverters are off-grid to supply power to the load, and the second preset value is greater than the first preset value.

2. A control method for connecting an energy storage inverter in parallel to a diesel generator and a power grid as claimed in claim 1, characterized in that: In step S4, when the first preset condition is met, the diesel generator is controlled to start so that the diesel generator supplies power to the load and charges the battery corresponding to the part of the energy storage inverter respectively, which specifically includes: Determining whether the remaining energy storage inverter can support the load operation to obtain first determination information; If the first judgment information is that the remaining energy storage inverter can support the load operation, then the part of the energy storage inverter is controlled to stop discharging and the other energy storage inverters continue to operate. If the first judgment information is that the remaining energy storage inverter cannot support the load operation, then the diesel generator is controlled to start, so that the diesel generator supplies power to the load and charges the battery corresponding to the part of the energy storage inverter.

3. A control method for connecting an energy storage inverter in parallel to a diesel generator and a power grid as claimed in claim 2, characterized in that: Determining whether the remaining energy storage inverter can support the load operation to obtain the first determination information specifically includes: Respectively obtaining the load power required for load operation and the first preset power output by each remaining energy storage inverter; Calculating and acquiring a first total power of the remaining energy storage inverters according to a first preset power output by each remaining energy storage inverter; If the first total power is not less than the load power, the first judgment information is that the remaining energy storage inverter can support the load operation. If the first total power is less than the load power, the first judgment information is that the remaining energy storage inverter cannot support the load operation.

4. The control method for connecting the energy storage inverter in parallel to the diesel generator and the power grid as claimed in claim 1, 2 or 3, characterized in that: In step S5, when the real-time remaining power of all energy storage inverters is greater than the second preset value and the second preset condition is met, controlling the diesel generator to shut down and all energy storage inverters to start specifically includes: When the real-time remaining power of all energy storage inverters is greater than the second preset value, determining whether all energy storage inverters can support load operation to obtain second determination information; If the second judgment information is that all energy storage inverters cannot support the load operation, the diesel generator is controlled to continue running. If the second judgment information is that all energy storage inverters can support the load operation, the diesel generator is controlled to be shut down and all energy storage inverters are started, so that all energy storage inverters are off-grid to supply power to the load.

5. The control method for connecting the energy storage inverter in parallel to the diesel generator and the power grid as claimed in claim 1, 2 or 3, characterized in that: The diesel generator separately supplies power to the load and charges the battery corresponding to the part of the energy storage inverter, including: obtaining the corresponding relationship between the charging power of the diesel generator for charging the battery and the remaining power of the battery, obtaining the real-time charging power of the battery corresponding to the energy storage inverter based on the corresponding relationship and the real-time remaining power of the battery corresponding to the energy storage inverter, and charging the battery corresponding to the energy storage inverter by the diesel generator based on the real-time charging power.

6. A control system in which an energy storage inverter is connected in parallel to a diesel generator and a power grid, characterized in that: It includes a determination control module, a collection module, a diesel generator, multiple energy storage inverters, and multiple batteries; A plurality of the energy storage inverters are arranged in parallel, and each of the energy storage inverters is respectively connected to a corresponding battery; The acquisition module is used to obtain the real-time remaining power of all batteries respectively; The determination control module is used to control the part of the energy storage inverters to stop discharging when the real-time remaining power of the battery corresponding to at least one energy storage inverter is less than a first preset value, and to control the diesel generator to start when the first preset condition is met, so that the diesel generator supplies power to the load and charges the battery corresponding to the part of the energy storage inverter respectively; when the real-time remaining power of all the energy storage inverters is greater than a second preset value and the second preset condition is met, control the diesel generator to shut down and all the energy storage inverters to start, so that all the energy storage inverters are off-grid to supply power to the load, and the second preset value is greater than the first preset value.

7. A control system for connecting an energy storage inverter in parallel to a diesel generator and a power grid as claimed in claim 6, characterized in that: The determination control module includes a first control unit and a first determination unit; The first control unit is used to control the energy storage inverters to stop discharging when the real-time remaining power of the battery corresponding to at least one energy storage inverter is less than a first preset value; The first determination unit is used to determine whether the remaining energy storage inverter can support the load operation to obtain first determination information; The first control unit is used to control the part of the energy storage inverter to stop discharging and the other energy storage inverters to continue operating if the first judgment information is that the remaining energy storage inverter can support the load operation; if the first judgment information is that the remaining energy storage inverter cannot support the load operation, control the diesel generator to start, so that the diesel generator supplies power to the load and charges the battery corresponding to the part of the energy storage inverter.

8. A control system for connecting an energy storage inverter in parallel to a diesel generator and a power grid as claimed in claim 7, characterized in that: The first determination unit determines whether the remaining energy storage inverter can support the load operation to obtain the first determination information, specifically including: respectively obtaining the load power required for the load operation and the first preset power output by each remaining energy storage inverter; Calculating and acquiring a first total power of the remaining energy storage inverters according to a first preset power output by each remaining energy storage inverter; If the first total power is not less than the load power, the first judgment information is that the remaining energy storage inverter can support the load operation. If the first total power is less than the load power, the first judgment information is that the remaining energy storage inverter cannot support the load operation.

9. A control system in which an energy storage inverter is connected in parallel to a diesel generator and a power grid as claimed in claim 7 or 8, characterized in that: The first determination unit also includes: when the real-time remaining power of all energy storage inverters is greater than a second preset value, determining whether all energy storage inverters can support the load operation to obtain second determination information; the first control unit also includes: if the second determination information is that all energy storage inverters cannot support the load operation, controlling the diesel generator to continue to run; if the second determination information is that all energy storage inverters can support the load operation, controlling the diesel generator to shut down and all energy storage inverters to start, so that all energy storage inverters are off-grid to supply power to the load.

10. A control system in which an energy storage inverter is connected in parallel to a diesel generator and a power grid as claimed in claim 6, 7 or 8, characterized in that: The determination control module includes the following steps when the diesel generator supplies power to the load and charges the battery corresponding to the part of the energy storage inverter: obtaining the corresponding relationship between the charging power of the diesel generator for charging the battery and the remaining power of the battery, obtaining the real-time charging power of the battery corresponding to the energy storage inverter based on the corresponding relationship and the real-time remaining power of the battery corresponding to the energy storage inverter, and charging the battery corresponding to the energy storage inverter by the diesel generator based on the real-time charging power.

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