Energy storage system control method, control device and control equipment

Abstract

The present application discloses a control method, control device and control equipment for an energy storage system, which relates to the technical field of drilling platforms and is used for offline power grids. The energy storage system includes an energy storage inverter, a battery cluster and a diesel generator set. The battery cluster discharges to the offline power grid through the energy storage inverter, and the diesel generator set charges the battery cluster through the energy storage inverter. The method includes: obtaining the state of charge SOC of the battery cluster and the load rate of the diesel generator set; controlling the energy storage inverter to work according to the state of charge SOC and the load rate, so as to charge, discharge or control the energy storage inverter to standby. By cooperating with the diesel generator set, the energy storage inverter and the battery cluster, and utilizing the fast response and high power quality characteristics of the battery cluster, according to the load rate and control logic of the diesel generator set, the shortcomings of the diesel generator set can be effectively compensated, the working efficiency of the diesel generator can be improved, and fuel consumption can be reduced.

Description

Technical Field

[0001] The present application relates to the technical field of drilling platforms, and in particular to a control method, a control device and a control equipment for an energy storage system. Background Art

[0002] Oil drilling sites are mostly located in remote areas with sparse population and far away from towns. The power supply and distribution network of the national power grid cannot cover them. If a dedicated line is to be laid to the drilling site, the construction cost is high and the construction is difficult. In addition, the power load at the drilling site decreases sharply after the mining is completed. The establishment of a dedicated line will cause serious waste of resources. Therefore, diesel generator sets are often used as the main power supply at the drilling site. Multiple diesel generators are connected in parallel to build an off-grid system to power high-power motor equipment such as winches and mud pumps on site.

[0003] The power required during the drilling process is different. When the drilling process does not encounter hard rock formations or the drill is not stuck, some of the multiple generators are working and the other part is in a low-load standby state. When encountering the above problems, the generators in standby state also join the work, so that the drilling equipment can get power replenishment in time.

[0004] Due to the particularity of drilling operation load, the on-site load fluctuation is particularly large, which will cause some diesel generator sets to operate at a low level for a long time and the load rate is not high, which will also lead to low power generation efficiency, high fuel consumption and large emissions. Summary of the invention

[0005] The main purpose of the present application is to provide an energy storage system control method, a control device and a control equipment, aiming to solve the technical problem of high fuel consumption of diesel generator sets.

[0006] To achieve the above object, the present application proposes a method for controlling an energy storage system for an offline power grid, wherein the energy storage system comprises an energy storage inverter, a battery cluster and a diesel generator set, wherein the battery cluster discharges to the offline power grid through the energy storage inverter, and the diesel generator set charges the battery cluster through the energy storage inverter, wherein the method comprises:

[0007] Detecting a load change of the diesel generator set, and acquiring a state of charge SOC of the battery cluster and a load rate N of the diesel generator set;

[0008] According to the load change of the diesel generator set, the state of charge SOC of the battery cluster and the load rate N of the diesel generator set, the energy storage converter is controlled to operate in a corresponding operating mode to charge or discharge the battery cluster or control the energy storage converter to standby; wherein,

[0009] The state of charge (SOC) of the battery cluster indicates the remaining power or charging degree of the battery cluster;

[0010] The load rate N of the diesel generator set is obtained by the following formula:

[0011] N=P3 / (Sn*M)

[0012] Among them, P3 is the real-time total active power of the load, Sn is the rated capacity of a single diesel generator set, and M is the number of diesel generator sets running online in real time.

[0013] In one embodiment, the step of controlling the energy storage converter to operate in a corresponding operating mode according to the load change of the diesel generator set, the state of charge SOC of the battery cluster and the load rate N of the diesel generator set to charge or discharge the battery cluster or control the energy storage converter to standby includes:

[0014] When the load change detects a load increase, detecting the state of charge SOC of the battery cluster and the load rate N of the diesel generator set;

[0015] When the load rate N≥preset value and the state of charge SOC≥state of charge SOC1, the energy storage converter is controlled to discharge at a preset discharge power so that the battery cluster discharges to the offline power grid.

[0016] In one embodiment, when the load rate N ≥ the preset value and the state of charge SOC ≥ the state of charge SOC1, the step of controlling the energy storage converter to discharge at a first preset discharge power so that the battery cluster discharges to the offline power grid includes:

[0017] When the load rate N≥N1 and the state of charge SOC≥state of charge SOC1, the energy storage converter is controlled to discharge at a first preset discharge power so that the battery cluster discharges to the offline power grid, and prompt information for starting M+1 diesel generators is output;

[0018] When the load rate N≥N1 and the state of charge SOC<state of charge SOC1, the energy storage converter is controlled to standby and a prompt message for starting M+1 diesel generators is output;

[0019] Among them, N1 is the first threshold value of the load rate of the diesel generator set.

[0020] In one embodiment, when the load rate N ≥ the preset value and the state of charge SOC ≥ the state of charge SOC1, the step of controlling the energy storage converter to discharge at a first preset discharge power so that the battery cluster discharges to the offline power grid includes:

[0021] When the load rate N2≤N<N1 and the state of charge SOC≥state of charge SOC1, the number M of current online diesel generators is obtained;

[0022] When M=1, the energy storage converter is controlled to discharge at a second preset discharge power so that the battery cluster discharges to the offline power grid;

[0023] When M>1, the energy storage converter is controlled to discharge at a third preset discharge power so that the battery cluster discharges to the offline power grid;

[0024] When the load rate N2≤N<N1, and the state of charge SOC<state of charge SOC1, controlling the energy storage converter to standby;

[0025] detecting a state of charge (SOC) of the battery cluster within a first time interval;

[0026] When the state of charge SOC of the battery cluster is less than the state of charge SOC1 within the first time interval, outputting prompt information for starting M+1 diesel generators;

[0027] If the state of charge SOC of the battery cluster is greater than or equal to the state of charge SOC1 within the first time interval, the step of detecting the load change of the diesel generator set and obtaining the state of charge SOC of the battery cluster and the load rate N of the diesel generator set is performed;

[0028] Among them, N2 is the second threshold value of the load rate of the diesel generator set.

[0029] In one embodiment, the step of controlling the energy storage converter to operate in a corresponding operating mode according to the load change of the diesel generator set, the state of charge SOC of the battery cluster and the load rate N of the diesel generator set to charge or discharge the battery cluster or control the energy storage converter to standby includes:

[0030] When the load rate N3≤N<N2 and the state of charge SOC≥state of charge SOC1, controlling the energy storage converter to discharge at a fourth preset discharge power so that the battery cluster discharges to the offline power grid;

[0031] When the load rate N3≤N<N2, and the state of charge SOC<state of charge SOC1, the energy storage converter is controlled to standby, and a prompt message that the diesel generator set maintains the current status is output;

[0032] Among them, N3 is the third threshold value of the load rate of the diesel generator set.

[0033] In one embodiment, the step of controlling the energy storage converter to operate in a corresponding operating mode according to the load change of the diesel generator set, the state of charge SOC of the battery cluster and the load rate N of the diesel generator set to charge or discharge the battery cluster or control the energy storage converter to standby includes:

[0034] When the load rate N4≤N<N3, the energy storage converter is controlled to be in standby mode, and a prompt message that the diesel generator set maintains the current status is output;

[0035] Among them, N4 is the fourth threshold value of the load rate of the diesel generator set.

[0036] In one embodiment, the step of controlling the energy storage converter to operate in a corresponding operating mode according to the load change of the diesel generator set, the state of charge SOC of the battery cluster and the load rate N of the diesel generator set to charge or discharge the battery cluster or control the energy storage converter to standby includes:

[0037] When the load rate N<N4 and the state of charge SOC>the state of charge SOC2, the energy storage converter is controlled to be in standby mode.

[0038] In one embodiment, the step of controlling the energy storage converter to operate in a corresponding operating mode according to the load change of the diesel generator set, the state of charge SOC of the battery cluster and the load rate N of the diesel generator set to charge or discharge the battery cluster or control the energy storage converter to standby includes:

[0039] When the load rate N is less than N4 and the state of charge SOC is less than or equal to the state of charge SOC2, the number M of current online diesel generators is obtained;

[0040] When M=1, controlling the energy storage converter to charge with a first preset charging power to charge the battery cluster;

[0041] When M=2, the state of charge SOC of the battery cluster in the first time interval is detected. If the state of charge SOC of the battery cluster in the first time interval is greater than or equal to the state of charge SOC2, the diesel generator set and the energy storage converter are controlled to maintain the status quo. After the first time interval, if the state of charge SOC of the battery cluster is less than the state of charge SOC2, the energy storage converter is controlled to charge with a second preset charging power to charge the battery cluster, and a prompt message of shutting down a diesel generator is output;

[0042] In the case where M≥3, the state of charge SOC of the battery cluster within the first time interval is detected. If the state of charge SOC of the battery cluster within the first time interval is ≥ the state of charge SOC2, the diesel generator set and the energy storage converter are controlled to maintain the status quo. After the first time interval, if the state of charge SOC of the battery cluster is < the state of charge SOC2, the energy storage converter is controlled to charge with a third preset charging power to charge the battery cluster, and a prompt message for shutting down a diesel generator is output, and the steps of detecting the load change of the diesel generator set and obtaining the state of charge SOC of the battery cluster and the load rate N of the diesel generator set are performed;

[0043] Among them, N4 is the fourth threshold value of the load rate of the diesel generator set.

[0044] The present application also proposes a control device for an energy storage conversion system, the control device for the energy storage conversion system comprising:

[0045] A detection module, used to detect the load change of the diesel generator set, and obtain the state of charge SOC of the battery cluster and the load rate N of the diesel generator set;

[0046] The working mode determination module is used to control the energy storage inverter to operate in a corresponding working mode according to the load change of the diesel generator set, the state of charge SOC of the battery cluster and the load rate N of the diesel generator set, so as to charge or discharge the battery cluster or control the energy storage inverter to standby.

[0047] The present application also proposes a control device for an energy storage conversion system, the control device for the energy storage conversion system comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, the computer program being configured to implement the steps of the energy storage system control method as described above.

[0048] The technical solution proposed in this application has at least the following technical effects:

[0049] By cooperating with the diesel generator set, the energy storage converter and the battery cluster, and utilizing the fast response and high power quality characteristics of the battery cluster, when the load rate of the diesel generator set is very high and the load charge of the offline power grid increases suddenly, the energy storage converter is controlled to work so that the battery cluster discharges to the offline power grid, and the output assists the diesel generator set to carry the load, overcomes the problem of starting an additional diesel generator to generate electricity, the additional diesel generator has a long start-up time, a slow output ramp speed, and is difficult to cope with the sudden increase in load, and reduces the number of diesel generators used, thereby achieving the goal of saving fuel. The power grid can be operated smoothly to avoid the adverse effects of the sudden increase in load on the offline power grid. The load rate of the diesel generator set is low, and the power generation per unit fuel consumption is small. At this time, it is necessary to control the energy storage converter to work to charge the battery cluster, so as to increase the load rate of the diesel generator and increase the power generation per unit fuel consumption of the diesel generator. When the load rate of the diesel generator set is low and the power generation per unit fuel consumption is small, the energy storage converter works to charge the battery cluster, so as to increase the load rate of the diesel generator, increase the power generation per unit fuel consumption of the diesel generator, and reduce the fuel consumption of the diesel generator set. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0051] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0052] Figure 1 A schematic diagram of a flow chart provided for the first embodiment of the energy storage system control method of the present application;

[0053] Figure 2 A schematic diagram of a flow chart provided for Embodiment 2 of the energy storage system control method of the present application;

[0054] Figure 3 A flowchart of the third embodiment of the energy storage system control method of the present application is provided;

[0055] Figure 4 A flowchart of the fourth embodiment of the energy storage system control method of the present application is provided;

[0056] Figure 5 A flowchart of Embodiment 5 of the energy storage system control method of the present application is provided;

[0057] Figure 6 A flowchart of the sixth embodiment of the energy storage system control method of the present application is provided;

[0058] Figure 7 A flow chart of Embodiment 7 of the energy storage system control method of the present application;

[0059] Figure 8 A flow chart of Embodiment 8 of the energy storage system control method of the present application;

[0060] Fig. 9 A structural diagram of an embodiment of a control device for an energy storage conversion system of the present application is provided.

[0061] The purpose, features and advantages of this application will be further described in conjunction with the embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0062] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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 ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0063] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0064] In addition, the descriptions of "first", "second", etc. in the present invention are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0065] Oil drilling sites are mostly located in remote areas with sparse population and far away from towns. The power supply and distribution network of the national power grid cannot cover them. If a dedicated line is to be laid to the drilling site, the construction cost is high and the construction is difficult. In addition, the power load at the drilling site decreases sharply after the mining is completed. The establishment of a dedicated line will cause serious waste of resources. Therefore, diesel generator sets are often used as the main power supply at the drilling site. Multiple diesel generators are connected in parallel to build an off-grid system to power high-power motor equipment such as winches and mud pumps on site.

[0066] The power required during the drilling process is different. When the drilling process does not encounter hard rock formations or the drill is not stuck, some of the multiple generators are working and the other part is in a low-load standby state. When encountering the above problems, the generators in standby state also join the work, so that the drilling equipment can get power replenishment in time.

[0067] Due to the particularity of drilling operation load, the on-site load fluctuation is particularly large, which will cause some diesel generator sets to operate at a low level for a long time and the load rate is not high, which will also lead to low power generation efficiency, high fuel consumption and large emissions.

[0068] In order to solve the above problems, the present invention proposes a method for controlling an energy storage system, aiming to solve the technical problem of high fuel consumption of a diesel generator set.

[0069] Energy storage system refers to a system that can store energy through a medium or device and release it when it is needed. Energy storage system usually consists of a medium or device for storing energy, a device for converting energy, and a device for managing stored energy.

[0070] It should be noted that the execution subject of this embodiment can be an EMS energy management system, or a computing service device with data processing, network communication and program running functions, such as a tablet computer, a personal computer, a mobile phone, etc., or a thermal management device of a PCS energy storage system that can realize the above functions, etc. This embodiment does not specifically limit this. The following takes the EMS energy management system as an example to illustrate this embodiment and the following embodiments.

[0071] Please refer to Figure 1 , Figure 1 The flowchart of the first embodiment of the energy storage system control method of the present application is provided. The energy storage system control method proposed in the present application is used for an offline power grid. The energy storage system control method includes steps S100 to S200, wherein:

[0072] Step S100, detecting a load change of the diesel generator set, and acquiring a state of charge SOC of the battery cluster and a load rate N of the diesel generator set;

[0073] Step S200, controlling the energy storage converter to operate in a corresponding operating mode according to the load change of the diesel generator set, the state of charge SOC of the battery cluster and the load rate N of the diesel generator set, so as to charge or discharge the battery cluster or control the energy storage converter to standby; wherein,

[0074] The state of charge (SOC) of the battery cluster indicates the remaining power or charging degree of the battery cluster;

[0075] The load rate N of the diesel generator set is obtained by the following formula:

[0076] N=P3 / (Sn*M)

[0077] Among them, P3 is the real-time total active power of the load, Sn is the rated capacity of a single diesel generator set, and M is the number of diesel generator sets running online in real time.

[0078] In this embodiment, the offline power grid includes an energy storage system, a bus and a load, and the energy storage system includes an energy storage inverter, a battery cluster and a diesel generator set. The battery cluster is electrically connected to the energy storage inverter. The energy storage inverter, the diesel generator set and the load are electrically connected to the bus. The number of the energy storage inverter can be one or more.

[0079] The battery cluster discharges to the load through the energy storage converter and the busbar, and the diesel generator set charges the battery cluster through the busbar and the energy storage converter.

[0080] It is understandable that the energy storage converter can realize the bidirectional conversion of AC and DC electric energy, and can invert the DC power stored in the battery in the battery cluster into AC power and output it to the bus, or rectify the AC power output by the diesel generator into DC power to charge the battery in the battery cluster. For example, when the diesel generator set is supplying power normally, or the diesel generator set has surplus energy, or the battery cluster is too low in power, the energy storage converter can work in the charging mode of charging the battery cluster, and when encountering a sudden load increase, the energy storage converter can also work in the discharge mode of supplying power to the load through the grid bus with the energy discharged by the battery cluster, and of course it can also work in the standby mode. When charging each battery, each battery cluster is equivalent to a load. When the batteries of each battery cluster are discharged, they are equivalent to a power supply device. The energy storage converter can also be provided with a controller, such as a bottom controller and a communication controller, and the communication controller is connected to the electronic control components, system controller (master control), etc. in the battery cluster, such as an energy management system, through a field bus. The bottom controller can control the energy conversion function of the inverter. The bottom controller can be a control chip such as DSP and single-chip microcomputer. The communication controller can realize dry contact, CAN bus, SPI and other communications. The energy storage converter can complete the sampling, conditioning and digitization of given signals such as voltage, current, switch quantity signals, etc. according to the hardware equipment configured based on its own control needs, collect and quickly calculate digital signals, output PWM signals, switch quantity output signals, etc., and perform real-time control on the corresponding controlled units, such as IGBT control in bidirectional inverters, main circuit breakers, and contactor opening and closing control.

[0081] The energy storage inverter has a VSG functional mode. The VSG function is a virtual synchronous generator technology that embeds the mathematical model of the synchronous generator into the control algorithm of the inverter, simulates the operation technology of the static power electronic device as a rotating motor, and simulates the primary frequency modulation and voltage regulation of the synchronous generator to enable it to have the functions of damping rapid fluctuations in voltage and frequency, automatic power distribution, and synchronous grid operation.

[0082] After the VSG function is enabled, the VSG is put into use. The VSG adopts droop control, which is mainly used for ms-level response when the load increases or decreases suddenly. When the bus voltage amplitude increases or decreases, the energy storage converter working in the VSG mode controls the output of reactive power through calculation to make the bus voltage work in a normal range; when the bus frequency increases or decreases, the energy storage converter controls the output of active power to stabilize the bus frequency in a reasonable range of 50Hz.

[0083] In this embodiment, the state of charge SOC of the battery cluster and the load rate of the diesel generator set are first obtained, and the battery cluster state is determined to meet the charging or discharging requirements according to the state of charge SOC of the battery cluster. The working state of the diesel generator set is determined to be too high according to the load rate of the diesel generator set and the load change of the diesel generator set, and the battery cluster needs to discharge to assist the diesel generator set in carrying the load. It should be noted that "state of charge SOC" is the abbreviation of State of Charge, that is, the state of charge of the battery, which indicates the remaining power or charging degree of the battery.

[0084] Alternatively, it is determined based on the load rate of the diesel generator set and the load change of the diesel generator set whether the working state of the diesel generator set is too low, and the diesel generator set needs to be made to generate electricity, and the energy storage inverter is controlled to charge the battery cluster to increase the load rate of the diesel generator set, thereby improving the working efficiency of the diesel generator and reducing fuel consumption.

[0085] In this embodiment, when the load rate of the diesel generator set is low, the chemical energy of the fuel is converted into electrical energy and stored for standby use by making the diesel generator set generate electricity and controlling the energy storage inverter to charge the battery cluster; this can increase the load rate of the diesel generator set, improve the working efficiency of the diesel generator, and reduce fuel consumption.

[0086] Since the load rate of the diesel generator set is very high and an additional diesel generator is started to generate electricity when the load charge of the offline power grid increases suddenly, the additional diesel generator has a long start-up time and a slow output ramp speed, making it difficult to cope with the sudden increase in load.

[0087] Therefore, in this embodiment, the diesel generator set cooperates with the energy storage converter and the battery cluster, and the battery cluster has the characteristics of fast response and high power quality. When the load rate of the diesel generator set is very high and the load charge of the offline power grid increases suddenly, the energy storage converter is controlled to work so that the battery cluster discharges to the offline power grid, and the output assists the diesel generator set to carry the load, thereby overcoming the problem of starting an additional diesel generator to generate electricity, the additional diesel generator has a long start-up time, a slow output ramp speed, and is difficult to cope with the sudden increase in load, and the number of diesel generators used is reduced, thereby achieving the goal of saving fuel. The power grid can be operated smoothly, and the sudden increase in load can be avoided from causing adverse effects on the offline power grid.

[0088] By making the diesel generator set generate electricity and controlling the energy storage inverter to charge the battery cluster, the chemical energy of the fuel is converted into electrical energy and stored for standby use; the load rate of the diesel generator set can be increased, the working efficiency of the diesel generator can be improved, and fuel consumption can be reduced.

[0089] When it is determined according to the load rate of the diesel generator set that the working state of the diesel generator set is in a high-efficiency range, the energy storage converter is controlled to be in standby mode so that the diesel generator set is maintained in a high-efficiency working range.

[0090] It should be noted that the diesel generator set in the present invention includes a plurality of diesel generators with the same rated capacity, the rated capacity of each diesel generator is Sn, and the load rate N of the diesel generator set is obtained by the following formula:

[0091] N=P3 / (Sn*M)

[0092] When the rated capacity of each diesel generator is 1200 kW, the load rate is obtained by the following formula:

[0093] N=P3 / (1200kW*M)

[0094] Where P3 is the real-time total load active power, and M is the number of diesel generator sets running online in real time. It is understandable that the rated capacity of different models of diesel generators is generally different.

[0095] In this embodiment, the load rate is determined by the working curve and load of the diesel generator.

[0096] In one possible implementation, reference Figure 2 , Figure 2A flow chart of Embodiment 2 of the energy storage system control method of the present application. Step S200, the step of controlling the energy storage converter to operate in a corresponding operating mode according to the load change of the diesel generator set, the state of charge SOC of the battery cluster and the load rate N of the diesel generator set to charge or discharge the battery cluster or control the energy storage converter to standby includes:

[0097] S210, when the load change detects a load increase, detecting the state of charge SOC of the battery cluster and the load rate N of the diesel generator set;

[0098] S220 , when the load rate N ≥ a preset value and the state of charge SOC ≥ the state of charge SOC1 , control the energy storage converter to discharge at a preset discharge power so that the battery cluster discharges to the offline power grid.

[0099] In this embodiment, when the load rate N ≥ the preset value, the diesel generator set operates under a higher load. At this time, facing a sudden increase in load, if an additional diesel generator is started to generate electricity, the additional diesel generator has a long start-up time and a slow output climbing speed, which makes it difficult to cope with the sudden increase in load.

[0100] In this embodiment, in order to cope with the sudden increase in load, when the load increase is detected, the energy storage converter is controlled to work so that the battery cluster discharges to the offline power grid, and the output assists the diesel generator set to carry the load, so that the offline power grid can operate smoothly. Avoid starting additional diesel generators for power generation. The additional diesel generators have a long startup time and a slow output ramp speed, which makes it difficult to cope with the sudden increase in load. The number of diesel generators used can be reduced, thereby achieving the goal of saving fuel.

[0101] In one possible implementation, reference Figure 3 , Figure 3 A flow chart of Embodiment 3 of the energy storage system control method of the present application is provided. S220, when the load rate N ≥ the preset value and the state of charge SOC ≥ the state of charge SOC1, the step of controlling the energy storage converter to discharge at a preset discharge power so that the battery cluster discharges to the offline power grid includes:

[0102] S221, when the load rate N≥N1 and the state of charge SOC≥state of charge SOC1, control the energy storage converter to discharge at a first preset discharge power so that the battery cluster discharges to the offline power grid, and outputs prompt information for starting M+1 diesel generators;

[0103] S222, when the load rate N≥N1 and the state of charge SOC<state of charge SOC1, control the energy storage converter to standby and output prompt information for starting M+1 diesel generators;

[0104] Among them, N1 is the first threshold value of the load rate of the diesel generator set.

[0105] In this embodiment, N1 can be set to 90% of the rated power of the diesel generator set. When the load rate N≥N1, the state of charge SOC≥state of charge SOC1. The load rate of the diesel generator set is already very high, the battery cluster is in good condition and has discharge capacity. If there is another sudden increase in load, it will pose a great threat to the stability of the system. If it takes time to start another diesel generator, the battery cluster is put into use first.

[0106] Before the battery cluster is put into use, the real-time state of charge SOC value is judged first, and the real-time state of charge SOC value is compared with the state of charge SOC1 discharge lower limit parameter. The state of charge SOC1 defaults to 20%, which can also be adjusted according to actual conditions. The purpose of comparing the actual state of charge SOC value with the discharge lower limit state of charge SOC1 is to avoid over-discharge of the battery, which is a protection for the battery system.

[0107] When the state of charge SOC is less than the state of charge SOC1, the battery cluster is already insufficient and the load will no longer be guaranteed. Priority will be given to ensuring the safety of the battery cluster. The EMS management system sends 0 power to the energy storage inverter, putting it in standby mode, and charging when the load rate of the diesel generator set is low.

[0108] It is understandable that the values ​​of N1 and the state of charge SOC1 can be set according to actual conditions.

[0109] In this embodiment, in order to cope with sudden load increases, when a load increase is detected, the energy storage inverter is controlled to discharge at a first preset discharge power, so that the battery cluster discharges to the offline power grid, and the output assists the diesel generator set to carry the load, so that the offline power grid can operate smoothly. Avoid starting additional diesel generators for power generation. Additional diesel generators have a long start-up time and a slow output ramp speed, which makes it difficult to cope with sudden load increases. The number of diesel generators used can be reduced, thereby achieving the goal of saving fuel. Among them, the first preset discharge power can be P=min(250, P1 / 2), and P1 is the maximum requested discharge power of the energy storage inverter.

[0110] In this embodiment, after the additional diesel generator is started, step S200 is executed to control the energy storage inverter to operate in a corresponding working mode according to the load change of the diesel generator set, the state of charge SOC of the battery cluster and the load rate N of the diesel generator set, so as to charge, discharge or control the energy storage inverter to standby mode.

[0111] In one possible implementation, reference Figure 4 , Figure 4 A flowchart diagram of Embodiment 4 of the energy storage system control method of the present application. S220, when the load rate N ≥ the preset value and the state of charge SOC ≥ the state of charge SOC1, the step of controlling the energy storage converter to discharge at a preset discharge power so that the battery cluster discharges to the offline power grid includes:

[0112] S223, when the load rate N2≤N<N1, and the state of charge SOC≥state of charge SOC1, obtaining the number M of current online diesel generators;

[0113] S224, when M=1, controlling the energy storage converter to discharge at a second preset discharge power so that the battery cluster discharges to the offline power grid;

[0114] S225, when M>1, controlling the energy storage converter to discharge at a third preset discharge power, so that the battery cluster discharges to the offline power grid;

[0115] S226, when the load rate N2≤N<N1, and the state of charge SOC<state of charge SOC1, control the energy storage converter to standby;

[0116] S227, detecting the state of charge SOC of the battery cluster within a first time interval;

[0117] S228, when the state of charge SOC of the battery cluster is less than the state of charge SOC1 within the first time interval, outputting a prompt message for starting M+1 diesel generators;

[0118] S229, if the state of charge SOC of the battery cluster is greater than or equal to the state of charge SOC1 within the first time interval, executing the step of detecting the load change of the diesel generator set and obtaining the state of charge SOC of the battery cluster and the load rate N of the diesel generator set;

[0119] Among them, N2 is the second threshold value of the load rate of the diesel generator set.

[0120] In this embodiment, N2 can be set to 70% of the rated power of the diesel generator set. When the load rate N2≤N<N1, the load rate level of the diesel generator set is generally high. At this time, it is necessary to pay attention to the occurrence of sudden load increases. In order to avoid the adverse effects of sudden load increases on the system, it is also necessary to control the discharge of the battery cluster to maintain the stable operation of the offline power grid.

[0121] Before the battery cluster is put into use, the real-time state of charge SOC value is judged first, and the real-time state of charge SOC value is compared with the state of charge SOC1 discharge lower limit parameter. The state of charge SOC1 defaults to 20%, and the operator can also adjust it according to actual conditions. The purpose of comparing the actual state of charge SOC value with the discharge lower limit state of charge SOC1 is to avoid over-discharge of the battery, which is a protection for the battery system.

[0122] When the state of charge SOC≥state of charge SOC1, the battery cluster is in a good state and has discharge capability.

[0123] It can be understood that the values ​​of N2 and the state of charge SOC1 can be set according to actual conditions.

[0124] In this embodiment, before issuing a discharge instruction to control the energy storage converter to operate so as to discharge the battery cluster, the number of online diesel generators is first obtained, and the discharge power of the energy storage converter is determined according to the number of online diesel generators.

[0125] If it is detected that only one diesel generator is started, that is, M=1, the energy storage converter is controlled to discharge at the second preset discharge power to discharge the battery cluster to the offline power grid. The value of the second preset discharge power is P=min(P1 / 2, (P3-P4) / 2), P1 is the maximum requested discharge power of the energy storage BMS, P3 is the real-time total active power of the load, and P4 is the upper limit of the output of a single diesel generator.

[0126] If it is detected that M>1, that is, multiple diesel generators are started, the energy storage converter is controlled to discharge at a third preset discharge power so that the battery cluster discharges to the offline power grid. The third preset discharge power value is P=min(100, P1 / 2) for discharge.

[0127] In this embodiment, N3 can be set to 60% of the rated power of the diesel generator set. When the load rate N≥N3, the load rate of the diesel generator set is not too high.

[0128] The state of charge SOC1 is the lower limit of the discharge of the battery cluster, and is set to 20% by default. When the state of charge SOC ≥ the state of charge SOC1, the battery cluster is in a good state and has the discharge capability.

[0129] It is understandable that the values ​​of N3 and the state of charge SOC1 can be set according to actual conditions.

[0130] In this embodiment, in order to cope with the sudden increase in load, when the load increase is detected, the energy storage converter is controlled to work so that the battery cluster discharges to the offline power grid, and the output assists the diesel generator set to carry the load, so that the offline power grid can operate smoothly. Avoid starting additional diesel generators for power generation. The additional diesel generators have a long startup time and a slow output ramp speed, which makes it difficult to cope with the sudden increase in load. The number of diesel generators used can be reduced, thereby achieving the goal of saving fuel.

[0131] When the load rate N2≤N<N1, and the state of charge SOC<state of charge SOC1, the load rate level of the diesel generator set is generally high. At this time, it is necessary to pay attention to the occurrence of sudden load increases. In order to avoid the adverse effects of sudden load increases on the system, the battery cluster is already insufficient at this time, and the load will no longer be guaranteed. Priority is given to ensuring the safety of the battery cluster. The EMS management system sends 0 power to the energy storage inverter, putting it in standby mode, and charging when the load rate of the diesel generator set is low. When the state of charge SOC is always less than the state of charge SOC1 during the first standby time interval of the energy storage inverter, the power reserve of the battery cluster is insufficient to support the potential load demand. The EMS management system outputs the suggestion of "starting M+1 diesel generators", reminding the operator to start M+1 diesel generators as soon as possible to cope with sudden loads.

[0132] In this embodiment, the state of charge SOC is continuously monitored during the first time interval when the energy storage converter is on standby to see whether it reaches the lower discharge limit state of charge SOC1 of the energy storage system. If the state of charge SOC rises above the state of charge SOC1 during the first time interval, the system first maintains the current diesel generator working state unchanged without adding a new generator. This means that the current power production capacity is sufficient to meet the current power demand, and no additional diesel generators are required to be put into operation. At this time, the step of determining whether the state of charge SOC reaches the lower discharge limit state of charge SOC1 of the energy storage system is performed after the first time interval to prevent the battery cluster from over-discharging.

[0133] In one possible implementation, reference Figure 5 , Figure 5 A flowchart diagram of Embodiment 5 of the energy storage system control method of the present application. S200, the step of controlling the energy storage converter to operate in a corresponding operating mode according to the load change of the diesel generator set, the state of charge SOC of the battery cluster and the load rate N of the diesel generator set to charge, discharge or control the energy storage converter to standby mode also includes:

[0134] S230, when the load rate N3≤N<N2 and the state of charge SOC≥state of charge SOC1, controlling the energy storage converter to discharge at a fourth preset discharge power so that the battery cluster discharges to the offline power grid;

[0135] S240, when the load rate N3≤N<N2 and the state of charge SOC<state of charge SOC1, control the energy storage converter to standby and output a prompt message that the diesel generator set maintains the current status.

[0136] In this embodiment, N2 is the second threshold value of the diesel generator set load rate, and N2 can be set to 70% of the rated power of the diesel generator set. N3 is the third threshold value of the diesel generator set load rate, and N3 can be set to 60% of the rated power of the diesel generator set.

[0137] When the load rate N is greater than the third threshold N3 of the diesel generator set load rate and less than the second threshold N2 of the diesel generator set load rate, the load rate level of the diesel generator set is not too high. At this time, it is necessary to pay attention to the occurrence of sudden load increases. In order to avoid the adverse effects of sudden load increases on the system, when the state of charge SOC is less than the state of charge SOC1, it is also necessary to control the discharge of the battery cluster to maintain the stable operation of the offline power grid.

[0138] Before the battery cluster is put into use, the real-time state of charge SOC value is judged first, and the real-time state of charge SOC value is compared with the state of charge SOC1 discharge lower limit parameter. The state of charge SOC1 defaults to 20%, and the operator can also adjust it according to actual conditions. The purpose of comparing the actual state of charge SOC value with the discharge lower limit state of charge SOC1 is to avoid over-discharge of the battery, which is a protection for the battery system.

[0139] When the state of charge SOC ≥ state of charge SOC1, the battery cluster is in good condition and has discharge capacity. The battery cluster can be controlled to discharge at a fourth preset discharge power so that the battery cluster discharges to the offline power grid, thereby maintaining the stable operation of the offline power grid. Among them, the value of the fourth preset discharge power is P=min(P1 / 2, (P3-N3*1200*M) / 2), P1 is the maximum requested discharge power of the energy storage inverter, P3 is the real-time total load active power, N3 is the third threshold value of the diesel generator set load rate, and M is the number of diesel generator sets online in real time.

[0140] It can be understood that the values ​​of N2, N3 and the state of charge SOC1 can be set according to actual conditions.

[0141] In this embodiment, since the diesel generator load rate is not high at this time, there is no need to judge the number of diesel generators, and the discharge power can be directly sent to each energy storage inverter on average, and the energy storage inverter is controlled to discharge with a fourth preset discharge power value of P=min(P1 / 2, (P3-N3*1200*M) / 2).

[0142] When the load rate N is greater than the third threshold value N3, and the state of charge SOC is less than the state of charge SOC1, the load rate level of the diesel generator set is not too low. At this time, it is necessary to pay attention to the occurrence of sudden load increases. In order to avoid the adverse effects of sudden load increases on the system, it is also necessary to control the discharge of the battery cluster to maintain the stable operation of the offline power grid. However, the battery cluster is already insufficient at this time, and the load will no longer be guaranteed. Priority is given to ensuring the safety of the battery cluster. The EMS management system controls the energy storage inverter to standby and outputs a prompt message that the diesel generator set maintains the status quo.

[0143] In one possible implementation, reference Figure 6 , Figure 6 A flowchart diagram of Embodiment 6 of the energy storage system control method of the present application. S200, the step of controlling the energy storage converter to operate in a corresponding operating mode according to the load change of the diesel generator set, the state of charge SOC of the battery cluster and the load rate N of the diesel generator set to charge or discharge the battery cluster or control the energy storage converter to standby includes:

[0144] S250, when the load rate N4≤N<N3, control the energy storage converter to standby, and output a prompt message that the diesel generator set maintains the current status. Wherein N4 is the fourth threshold value of the load rate of the diesel generator set.

[0145] In this embodiment, N3 is the third threshold value of the load rate of the diesel generator set, and N3 can be set to 60% of the rated power of the diesel generator set. N4 is the fourth threshold value of the load rate of the diesel generator set, and N4 can be set to 30% of the rated power of the diesel generator set. When the load rate N is greater than N4 and less than N3, the diesel generator operates in a relatively ideal range, with both power generation surplus to cope with sudden load changes and its own power generation efficiency maintained at a relatively high level. The EMS management system sends 0 power to the energy storage inverter, putting it in standby mode and charging it when the load rate of the diesel generator set is low. The EMS management system also outputs a suggestion to "maintain the status quo of the diesel generator."

[0146] In one possible implementation, reference Figure 7 , Figure 7A flow chart of Embodiment 7 of the energy storage system control method of the present application. S200, the step of controlling the energy storage converter to operate in a corresponding operating mode according to the load change of the diesel generator set, the state of charge SOC of the battery cluster and the load rate N of the diesel generator set to charge or discharge the battery cluster or control the energy storage converter to standby includes:

[0147] S260 , when the load rate N<N4 and the state of charge SOC>the state of charge SOC2 , control the energy storage converter to standby.

[0148] In this embodiment, when the load rate of the diesel generator set is less than N4 (30% by default), it is assumed that the load rate of the diesel generator set is low, and the power generation per unit fuel consumption is low. At this time, it is necessary to control the charging of the energy storage system to increase the load rate of the diesel generator and increase the power generation per unit fuel consumption of the diesel generator. However, at this time, the state of charge SOC of the battery cluster is greater than the state of charge SOC2, and the power of the battery cluster is relatively abundant, so the energy storage converter is controlled to standby.

[0149] In one possible implementation, reference Figure 8 , Figure 8 A flow chart of Embodiment 8 of the energy storage system control method of the present application. S200, the step of controlling the energy storage converter to operate in a corresponding operating mode according to the load change of the diesel generator set, the state of charge SOC of the battery cluster and the load rate N of the diesel generator set to charge, discharge or control the energy storage converter to standby mode also includes:

[0150] S270, when the load rate N is less than N4 and the state of charge SOC is less than or equal to the state of charge SOC2, obtaining the number M of current online diesel generators;

[0151] S271, when M=1, controlling the energy storage converter to charge with a first preset charging power to charge the battery cluster;

[0152] S272, when M=2, detect the state of charge SOC of the battery cluster within the first time interval, if the state of charge SOC of the battery cluster within the first time interval is ≥ the state of charge SOC2, control the diesel generator set and the energy storage converter to maintain the status quo, after the first time interval, and when the state of charge SOC of the battery cluster is < the state of charge SOC2, control the energy storage converter to charge with a second preset charging power to charge the battery cluster, and output a prompt message to shut down a diesel generator;

[0153] S273, when M≥3, detect the state of charge SOC of the battery cluster within the first time interval, if the state of charge SOC of the battery cluster within the first time interval is ≥ the state of charge SOC2, control the diesel generator set and the energy storage converter to maintain the status quo, after the first time interval, and when the state of charge SOC of the battery cluster is < the state of charge SOC2, control the energy storage converter to charge with a third preset charging power to charge the battery cluster, output a prompt message to shut down a diesel generator, execute the steps of detecting the load change of the diesel generator set, and obtaining the state of charge SOC of the battery cluster and the load rate N of the diesel generator set;

[0154] Among them, N4 is the fourth threshold value of the load rate of the diesel generator set.

[0155] In this embodiment, when only one diesel generator is running, if its load rate is increased to more than 30%, the charging power of the energy storage system does not need to be too large, and the EMS management system controls the energy storage converter to charge at the first preset charging power to charge the battery cluster. The value of the first preset charging power is P=min(125, P2 / 2), and P2 is the maximum requested charging power of the energy storage BMS.

[0156] In this embodiment, when two diesel generators are running, a 30s delay is performed first. If the load rate N of the diesel generator set rises to more than 30% within the 30s delay time, the diesel generator and the energy storage system can maintain the status quo. If the load rate of the diesel generator set is still lower than 30% after the 30s delay, the energy storage system needs to be charged. The EMS management system controls the energy storage converter to charge with the second preset charging power to charge the battery cluster, and at the same time issues a prompt to the operator to "turn off one diesel generator" so that the remaining diesel generators can work at a relatively ideal load rate. Among them, the value of the second preset charging power is P=min(125, (1200*N3-P3) / 2, P2 / 2), N3 is the third threshold value of the diesel generator set load rate, P3 is the real-time load total active power, and P2 is the maximum requested charging power of the energy storage BMS.

[0157] In this embodiment, when three or more diesel generators are running, a 30s delay judgment is also required first. If the load rate of the diesel generator rises to more than 30% within the 30s delay time, the diesel generator and the energy storage system can maintain the status quo; if the load rate of the diesel generator set is still lower than 30% after the 30s delay, the energy storage system needs to be charged at this time, and the EMS management system controls the energy storage inverter to charge with the third preset charging power to charge the battery cluster, and at the same time issues a prompt of "turning off a diesel generator" to the operator so that the remaining diesel generators can operate at a more ideal load rate. However, even after turning off a diesel generator, the load rate of the remaining diesel generators may not necessarily be increased to more than 30%. Therefore, the logic needs to return to the starting stage and execute S200 to control the energy storage inverter to work according to the state of charge SOC and the load rate N to charge, discharge or control the energy storage inverter to standby. Among them, the value of the second preset charging power is P=min(125, P2 / 2), and P2 is the maximum requested charging power of the energy storage BMS.

[0158] The present invention cooperates with a diesel generator set, an energy storage converter and a battery cluster, and utilizes the characteristics of the battery cluster's fast response and high power quality. When the load rate of the diesel generator set is very high and the load charge of the offline power grid increases suddenly, the energy storage converter is controlled to work so that the battery cluster discharges to the offline power grid, and the output assists the diesel generator set to carry the load, thereby overcoming the problem of starting an additional diesel generator to generate electricity, the additional diesel generator has a long start-up time, a slow output ramp speed, and is difficult to cope with the sudden increase in load, and the number of diesel generators used is reduced, thereby achieving the goal of saving fuel. The power grid can be made to operate smoothly, and the sudden increase in load can be avoided from causing adverse effects on the offline power grid. The load rate of the diesel generator set is low, and the power generation per unit fuel consumption is small. At this time, it is necessary to control the energy storage converter to work to charge the battery cluster, thereby increasing the load rate of the diesel generator and increasing the power generation per unit fuel consumption of the diesel generator. When the load rate of the diesel generator set is low, and the power generation per unit fuel consumption is small, the energy storage converter works to charge the battery cluster, thereby increasing the load rate of the diesel generator, increasing the power generation per unit fuel consumption of the diesel generator, and reducing the fuel consumption of the diesel generator set.

[0159] The present application also proposes a control device for an energy storage conversion system, see Fig. 9 , the control device of the energy storage conversion system comprises:

[0160] The detection module 10 is used to detect the load change of the diesel generator set, and obtain the state of charge SOC of the battery cluster and the load rate N of the diesel generator set;

[0161] The working mode determination module 20 is used to control the energy storage inverter to operate in a corresponding working mode according to the load change of the diesel generator set, the state of charge SOC of the battery cluster and the load rate N of the diesel generator set, so as to charge or discharge the battery cluster or control the energy storage inverter to standby.

[0162] The control device of the energy storage conversion system provided by the present application adopts the energy storage system control method in the above embodiment, which can solve the technical problem of high fuel consumption of diesel generator sets in the prior art. Compared with the prior art, the beneficial effects of the control device of the energy storage conversion system provided by the present application are the same as the beneficial effects of the control device of the energy storage conversion system provided by the above embodiment, and other technical features in the control device of the energy storage conversion system are the same as the features disclosed in the above embodiment method, which will not be repeated here.

[0163] The present application also proposes a control device for an energy storage conversion system, the control device for the energy storage conversion system comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, the computer program being configured to implement the steps of the energy storage system control method as described above.

[0164] The above descriptions are only some embodiments of the present application, and are not intended to limit the patent scope of the present application. All equivalent structural changes made using the contents of the present application specification and drawings under the technical concept of the present application, or direct / indirect applications in other related technical fields are included in the patent protection scope of the present application.

Claims

1. A method for controlling an energy storage system for an offline power grid, characterized in that: The energy storage system includes an energy storage converter, a battery cluster and a diesel generator set. The battery cluster discharges to an offline power grid through the energy storage converter, and the diesel generator set charges the battery cluster through the energy storage converter. The method includes: Detecting a load change of the diesel generator set, and obtaining a state of charge SOC of the battery cluster and a load rate N of the diesel generator set; According to the load change of the diesel generator set, the state of charge SOC of the battery cluster and the load rate N of the diesel generator set, the energy storage converter is controlled to operate in a corresponding operating mode to charge or discharge the battery cluster or control the energy storage converter to standby, specifically including: When the load change detects a load increase, detecting the state of charge SOC of the battery cluster and the load rate N of the diesel generator set; When the load rate N≥N1 and the state of charge SOC≥state of charge SOC1, the energy storage converter is controlled to discharge at a first preset discharge power so that the battery cluster discharges to the offline power grid, and prompt information for starting M+1 diesel generators is output; When the load rate N≥N1 and the state of charge SOC<state of charge SOC1, the energy storage converter is controlled to standby and a prompt message for starting M+1 diesel generators is output; in, The state of charge SOC of the battery cluster indicates the remaining power or charging degree of the battery cluster, N1 is the first threshold value of the load rate of the diesel generator set, N1 is set to 90% of the rated power of the diesel generator set, and the state of charge SOC1 is the lower limit parameter of the discharge of the battery cluster; The load rate N of the diesel generator set is obtained by the following formula: N=P3 / (Sn*M) Where P3 is the real-time total load active power, Sn is the rated capacity of a single diesel generator set, and M is the number of diesel generator sets in real-time online operation; The first preset discharge power is P=min(250, P1 / 2), where P1 is the maximum requested discharge power of the energy storage BMS.

2. The method according to claim 1, characterized in that The step of controlling the energy storage converter to operate in a corresponding operating mode according to the load change of the diesel generator set, the state of charge SOC of the battery cluster and the load rate N of the diesel generator set to charge or discharge the battery cluster or control the energy storage converter to standby comprises: When the load rate N2≤N<N1 and the state of charge SOC≥state of charge SOC1, the number M of current online diesel generators is obtained; When M=1, the energy storage converter is controlled to discharge at a second preset discharge power so that the battery cluster discharges to the offline power grid; When M>1, the energy storage converter is controlled to discharge at a third preset discharge power so that the battery cluster discharges to the offline power grid; When the load rate N2≤N<N1, and the state of charge SOC<state of charge SOC1, controlling the energy storage converter to standby; detecting a state of charge (SOC) of the battery cluster within a first time interval; When the state of charge SOC of the battery cluster is less than the state of charge SOC1 within the first time interval, outputting prompt information for starting M+1 diesel generators; If the state of charge SOC of the battery cluster is greater than or equal to the state of charge SOC1 within the first time interval, the step of detecting the load change of the diesel generator set and obtaining the state of charge SOC of the battery cluster and the load rate N of the diesel generator set is performed; Wherein, N2 is the second threshold value of the load rate of the diesel generator set, and N2 is set to 70% of the rated power of the diesel generator set; The second preset discharge power value is P=min(P1 / 2, (P3-P4) / 2); The third preset discharge power value is P=min(100, P1 / 2); wherein, P4 is the upper limit of the output of a single diesel generator.

3. The method according to claim 1, characterized in that The step of controlling the energy storage converter to operate in a corresponding operating mode according to the load change of the diesel generator set, the state of charge SOC of the battery cluster and the load rate N of the diesel generator set to charge or discharge the battery cluster or control the energy storage converter to standby also includes: When the load rate N3≤N<N2 and the state of charge SOC≥state of charge SOC1, controlling the energy storage converter to discharge at a fourth preset discharge power so that the battery cluster discharges to the offline power grid; When the load rate N3≤N<N2, and the state of charge SOC<state of charge SOC1, the energy storage converter is controlled to standby, and a prompt message that the diesel generator set maintains the current status is output; Wherein, N2 is the second threshold value of the load rate of the diesel generator set, N3 is the third threshold value of the load rate of the diesel generator set, N2 is set to 70% of the rated power of the diesel generator set, and N3 is set to 60% of the rated power of the diesel generator set; The value of the fourth preset discharge power is P=min(P1 / 2, (P3-N3*1200*M) / 2).

4. The method according to claim 1, characterized in that The step of controlling the energy storage converter to operate in a corresponding operating mode according to the load change of the diesel generator set, the state of charge SOC of the battery cluster and the load rate N of the diesel generator set to charge or discharge the battery cluster or control the energy storage converter to standby comprises: When the load rate N4≤N<N3, the energy storage converter is controlled to be in standby mode, and a prompt message that the diesel generator set maintains the current status is output; Among them, N3 is the third threshold value of the diesel generator set load rate, N3 is set to 60% of the rated power of the diesel generator set, N4 is the fourth threshold value of the diesel generator set load rate, N4 is set to 30% of the rated power of the diesel generator set.

5. The method according to claim 1, characterized in that The step of controlling the energy storage converter to operate in a corresponding operating mode according to the load change of the diesel generator set, the state of charge SOC of the battery cluster and the load rate N of the diesel generator set to charge or discharge the battery cluster or control the energy storage converter to standby comprises: When the load rate N is less than N4 and the state of charge SOC is greater than the state of charge SOC2, the energy storage converter is controlled to be in standby mode, wherein: N4 is the fourth threshold value of the load rate of the diesel generator set, and N4 is set to 30% of the rated power of the diesel generator set.

6. The method according to claim 5, characterized in that The step of controlling the energy storage converter to operate in a corresponding operating mode according to the load change of the diesel generator set, the state of charge SOC of the battery cluster and the load rate N of the diesel generator set to charge or discharge the battery cluster or control the energy storage converter to standby comprises: When the load rate N is less than N4 and the state of charge SOC is less than or equal to the state of charge SOC2, the number M of current online diesel generators is obtained; When M=1, controlling the energy storage converter to charge with a first preset charging power to charge the battery cluster; When M=2, the state of charge SOC of the battery cluster in the first time interval is detected. If the state of charge SOC of the battery cluster in the first time interval is greater than or equal to the state of charge SOC2, the diesel generator set and the energy storage converter are controlled to maintain the status quo. After the first time interval, if the state of charge SOC of the battery cluster is less than the state of charge SOC2, the energy storage converter is controlled to charge with a second preset charging power to charge the battery cluster, and a prompt message of shutting down a diesel generator is output; In the case where M≥3, the state of charge SOC of the battery cluster within the first time interval is detected. If the state of charge SOC of the battery cluster within the first time interval is ≥ the state of charge SOC2, the diesel generator set and the energy storage converter are controlled to maintain the status quo. After the first time interval, if the state of charge SOC of the battery cluster is < the state of charge SOC2, the energy storage converter is controlled to charge with a third preset charging power to charge the battery cluster, and a prompt message for shutting down a diesel generator is output, and the steps of detecting the load change of the diesel generator set and obtaining the state of charge SOC of the battery cluster and the load rate N of the diesel generator set are performed; Among them, the value of the first preset charging power is P=min(125, P2 / 2), and P2 is the maximum requested charging power of the energy storage BMS; The value of the second preset charging power is P=min(125, (1200*N3-P3) / 2, P2 / 2), N3 is the third threshold value of the load rate of the diesel generator set, N3 is set to 60% of the rated power of the diesel generator set, and P4 is the upper limit of the output of a single diesel generator; The value of the third preset charging power is P=min(125, P2 / 2).

7. A control device for an energy storage conversion system, characterized in that: The control device of the energy storage conversion system is controlled based on the energy storage system control method according to claim 1, and the control device of the energy storage conversion system includes: A detection module is used to detect the load change of the diesel generator set and obtain the state of charge SOC of the battery cluster and the load rate N of the diesel generator set; The working mode determination module is used to control the energy storage converter to work in the corresponding working mode according to the load change of the diesel generator set, the charge state SOC of the battery cluster and the load rate N of the diesel generator set, so as to charge or discharge the battery cluster or control the energy storage converter to standby.

8. A control device for an energy storage conversion system, characterized in that: The control device of the energy storage conversion system includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer program is configured to implement the steps of the energy storage system control method according to any one of claims 1 to 6.

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