Energy storage system power following control method and terminal

Abstract

The application discloses a kind of energy storage system power following control method, comprising: according to the historical power of the last moment EMS system issued to PCS is modified according to the preset load power approach coefficient and power margin parameter, and the optimized power is obtained, and the optimized power is issued to PCS.It can be seen that the application optimizes the traditional peak clipping strategy regulation, both can meet the gradual following effect of power following requirement, also can meet the prevention of current counterflow on power grid, energy storage system can be regulated in real time according to EMS acquisition data power, ensure that energy storage power can be discharged, increase the economic benefit of energy storage system use.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of energy storage system management, in particular to an energy storage system power following control method and terminal. BACKGROUND

[0002] The increasing electricity demand in residents' homes, various new power devices such as intelligent floor heating, intelligent projection, etc. are becoming more and more popular in residents' homes, and the daily electricity consumption and peak power of each resident are increasing. At the same time, the equipment in the factory is gradually entering the pace of upgrading, and more intelligent and larger power equipment is replacing old equipment, and the daily electricity consumption and peak power of commercial electricity are also increasing.

[0003] The pressure of power grid load is increasing with the increase of residential, industrial and commercial electricity, and at the same time, in order to meet the needs of environmental protection and power transformation, thermal power plants are gradually closed down, and the power supply is becoming increasingly tight.

[0004] In the case of commercial electricity limit, using energy storage system and green power generation equipment such as photovoltaic, wind power or hydrogen fuel power generation system to form intelligent microgrid can effectively reduce the peak load of power grid and alleviate the load pressure of power grid through regulating energy flow, and play the role of peak shaving.

[0005] When the existing energy storage system is directly connected to the AC bus for use, the difference between the load demand and the peak shaving and valley filling strategy power is usually calculated, and the difference is adjusted. However, the real load is a fluctuating value. When the fixed peak shaving and valley filling energy storage power value is set, if the actual load is greater than the output power of the energy storage, the energy storage capacity cannot be completely discharged in a fixed period, and the economic efficiency is not high. When the actual load is less than the output power of the energy storage, there is a risk that the energy storage capacity flows back to the power grid. SUMMARY

[0006] The technical problem to be solved by the present application is to provide an energy storage system power following control method and terminal, which can ensure slow power following and prevent energy storage system current from flowing back to the power grid.

[0007] In order to solve the above technical problems, the technical scheme adopted by the present application is:

[0008] An energy storage system power following control method, comprising:

[0009] According to the preset load power approach coefficient and power margin parameter, the historical power of the previous time EMS system issued to the PCS is corrected to obtain an optimized power, and the optimized power is issued to the PCS.

[0010] In order to solve the above technical problems, another technical scheme adopted by the present application is:

[0011] A kind of energy storage system power follow-up control terminal, including memory, processor and computer program stored on memory and can be run on processor, the processor carries out the following method when the computer program is implemented:

[0012] According to the preset load power approach coefficient and power margin parameter, the historical power of the last moment EMS system is issued to the PCS is corrected, the optimized power is obtained, and the optimized power is issued to the PCS.

[0013] The beneficial effects of the present application are that: a kind of energy storage system power follow-up control method and terminal, it optimizes the traditional peak clipping strategy control, both can meet the effect of gradual following approach of power follow-up coefficient power follow-up requirement, ensure that even if load power appears mutation in power follow-up process, it will not have great impact on power grid, simultaneously, through the setting of settable approach coefficient, the speed of approach can be controlled and adjusted;Also can meet the prevention of current reverse flow to power grid through the set power margin parameter, while load power changes, it can ensure that energy storage system will be according to the real-time control power of EMS acquisition data, according to the setting of local load fluctuation Condition adjustment margin, ensure that energy storage power can be discharged, increase the economic benefit of energy storage system use. BRIEF DESCRIPTION OF DRAWINGS

[0014] Fig. 1 It is the structure schematic view of the energy storage system of the embodiment of the present application;

[0015] Fig. 2 It is the setting schematic view of the peak clipping strategy of prior art;

[0016] Fig. 3 It is the structure schematic view of a kind of energy storage system power follow-up control terminal of the embodiment of the present application.

[0017] REFERENCE NUMERALS:

[0018] 1, a kind of energy storage system power follow-up control terminal;2, processor;3, memory. DETAILED DESCRIPTION

[0019] To explain the technical content of the present application, the purpose and effect realized, the following is explained by combining with the drawings.

[0020] Please refer to Figs. 1-2 A kind of method,

[0021] A kind of energy storage system power follow-up control method, comprising:

[0022] According to the preset load power approach coefficient and power margin parameter, the historical power of the last moment EMS system is issued to the PCS is corrected, the optimized power is obtained, and the optimized power is issued to the PCS.

[0023] The application has the advantages that the energy storage system power following control method and terminal optimize the traditional peak clipping and valley filling strategy regulation, can meet the gradual following effect of power following requirement through the power following coefficient, ensure that even if the load power suddenly changes, it will not have a great impact on the power grid during the power following process, and through the setting of the settable approaching coefficient, the approaching speed can be controlled and adjusted; and can prevent current reverse flow to the power grid through the set power margin parameter, ensure that the energy storage system can regulate the power in real time according to the EMS acquisition data when the load power changes, adjust the margin setting according to the local load fluctuation, ensure that the energy storage power can be discharged completely, and increase the economic benefit of the energy storage system.

[0024] Further, the power at the last moment issued by the EMS system to the PCS is corrected according to the load power approaching coefficient, and specifically,

[0025] The power at the last moment issued by the EMS system to the PCS is calculated according to the peak clipping and valley filling strategy, an evaluation power E is obtained, the difference between the historical power E' and E is calculated, the product of the difference between E' and E and the preset load power approaching coefficient is calculated, and the historical power E' is added to the product to obtain an optimized power.

[0026] The coefficient can be set according to requirements to adjust the approaching speed.

[0027] As described above, the gradual following effect meeting the power following requirement is realized.

[0028] Further, the power at the last moment issued by the EMS system to the PCS is corrected according to the power margin parameter, and specifically,

[0029] The evaluation power is subtracted by the power margin parameter to obtain an optimized power.

[0030] As described above, it is ensured that the current of the energy storage system will not flow to the power grid.

[0031] Further, the historical power at the last moment issued by the EMS system to the PCS is corrected according to the preset load power approaching coefficient and the power margin parameter, and specifically,

[0032] When the current power grid power is greater than or equal to the set value, the historical power at the last moment issued by the EMS system to the PCS is corrected according to the preset load power approaching coefficient;

[0033] When the current power grid power is less than the set value, the historical power at the last moment issued by the EMS system to the PCS is corrected according to the preset power margin parameter.

[0034] From the above description, the application scope of the two optimization methods is given.

[0035] Further, the power issued by the EMS system to the PCS at the previous moment is corrected based on the load power approaching coefficient and the power margin parameter, and specifically includes:

[0036] If the historical power E'>=0 and the current grid power A>=0, the power E'' issued by the EMS system to the PCS at the current moment is ((C-D)-E')*lambda+E';

[0037] In the formula, C is the power required by the load at the current moment, D is the input power of the alternating current power generation system, and lambda is the load power approaching coefficient.

[0038] If the historical power E'>=0 and the current grid power A<0, the power E'' issued by the EMS system to the PCS at the current moment is C-D-alpha;

[0039] In the formula, alpha is the power margin parameter related to the load fluctuation, and alpha>0.

[0040] If the historical power E'<0 and the current grid power A<alpha+beta, the power issued by the EMS system to the PCS at the current moment is according to the following formula:

[0041] E''=E'+((C-D)-alpha);

[0042] In the formula, beta is the judgment threshold power margin parameter related to the alternating current power generation system.

[0043] The margin parameter can be adjusted and set according to the local grid situation to ensure adaptation and not to exceed the margin setting.

[0044] If the historical power E'<0 and the current grid power A>=alpha+beta, the power issued by the EMS system to the PCS at the current moment is according to the following formula:

[0045] E''=((C'-D')-(C-D))*lambda+E'.

[0046] From the above description, the gradual following effect of meeting the power following requirement and preventing current reverse flow to the grid during the discharging process of the battery system is realized.

[0047] An energy storage system power following control terminal, comprising a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the following method when executing the computer program:

[0048] The historical power issued by the EMS system to the PCS at the previous moment is corrected according to the preset load power approaching coefficient and power margin parameter, an optimized power is obtained, and the optimized power is issued to the PCS.

[0049] As can be known from the above description, the energy storage system power following control method and terminal have the following beneficial effects: the traditional peak clipping and valley filling strategy regulation is optimized, the gradual following effect meeting the power following requirement is ensured, even if the load power suddenly changes, the power grid will not be greatly impacted, the approaching speed can be controlled and adjusted through the setting of the settable approaching coefficient, the current reverse flow to the power grid is prevented through the set power margin parameter, the energy storage system can regulate the power in real time according to the EMS acquisition data when the load power changes, the setting of the margin is adjusted according to the local load fluctuation, the energy storage power can be completely discharged, and the economic benefit of the energy storage system is increased.

[0050] Further, the power delivered by the EMS system to the PCS at the previous moment is corrected according to the load power approaching coefficient, and specifically,

[0051] the power delivered by the EMS system to the PCS at the current moment is calculated according to the peak clipping and valley filling strategy, an evaluation power E is obtained, the difference between a historical power E' and E is calculated, the product of the difference between E' and E and a preset load power approaching coefficient is calculated, and the historical power E' is added to the product to obtain an optimized power.

[0052] As can be known from the above description, the gradual following effect meeting the power following requirement is realized.

[0053] Further, the power delivered by the EMS system to the PCS at the previous moment is corrected according to the load power approaching coefficient, and specifically,

[0054] the evaluation power is subtracted by the power margin parameter to obtain the optimized power.

[0055] As can be known from the above description, the current of the energy storage system will not flow to the power grid.

[0056] Further, the historical power delivered by the EMS system to the PCS at the previous moment is corrected according to the preset load power approaching coefficient and the power margin parameter, and specifically,

[0057] when the current power grid power is greater than or equal to the set value, the historical power delivered by the EMS system to the PCS at the previous moment is corrected according to the preset load power approaching coefficient;

[0058] when the current power grid power is less than the set value, the historical power delivered by the EMS system to the PCS at the previous moment is corrected according to the preset power margin parameter.

[0059] As can be known from the above description, the application scope of the two optimization methods is given.

[0060] Furthermore, the correction based on the power sent from the EMS system to the PCS at the previous moment, according to the load power convergence coefficient and power margin parameters, specifically includes:

[0061] If the historical power E'>=0 and the current grid power A>=0, the power E” sent from the EMS system to the PCS at this moment is E”=((CD)-E')*λ+E';

[0062] In the formula, C is the power required by the load at the current moment, D is the current input power of the AC power generation system, and λ is the load power convergence coefficient;

[0063] If the historical power E'>=0 and the current grid power A<0, the power E” sent from the EMS system to the PCS at this moment is CD-α;

[0064] In the formula, α is the power margin parameter related to load fluctuation, and α>0;

[0065] If the historical power E' < 0 and the current grid power A < α + β, the power sent from the EMS system to the PCS at this moment is determined by the following formula:

[0066] E”=E'+((CD)-α);

[0067] In the formula, β is the judgment threshold power margin parameter related to the AC power generation system;

[0068] If the historical power E' < 0 and the current grid power A > α + β, the power sent from the EMS system to the PCS at this moment is determined by the following formula:

[0069] E"=((C'-D')-(CD))*λ+E'.

[0070] As described above, the battery system achieves a gradual power following effect during discharge, while also preventing current backflow into the power grid.

[0071] This invention is used in energy storage systems to control the charging and discharging power of the battery system, thereby enhancing economic efficiency and preventing backflow into the power grid.

[0072] Please refer to Figs. 1-2 Embodiment 1 of the present invention is as follows:

[0073] A power follower control method for energy storage systems, which is applied to, for example Fig. 1 The energy storage system architecture shown includes an EMS system, an AC bus, a battery system, a grid system, loads, and an AC power generation system. The grid system includes a step-up transformer, an AC contactor, and an AC transformer. The battery system includes a DC bus, an isolation transformer, a PCS, and multiple electrical cabinets.

[0074] The AC bus is electrically connected to the load and the power generation system. The AC bus is connected to the external power grid after passing through the AC contactor and the step-up transformer to draw power from the power grid. The AC transformer is installed on the line between the AC bus and the power grid to obtain the power input from the power grid. The AC bus is electrically connected to the DC bus through the isolation transformer and the PCS. Multiple electrical cabinets are electrically connected to the DC bus. The EMS system is electrically connected to the PCS bus, the AC transformer and the AC contactor.

[0075] In this architecture, the energy of the battery system is converted into AC power through an energy storage inverter and an isolation transformer, and then output to power the load. Alternatively, the energy storage inverter can convert AC power to DC power to charge the energy storage system. There can be multiple battery systems, and the EMS system can uniformly schedule the input or output of energy.

[0076] The load can be a residential load or a commercial load. The load can be a combination of various loads, and the total value of different loads combined is always fluctuating.

[0077] AC power generation systems can be different power generation systems such as photovoltaic power generation, wind power generation, diesel power generation, or hydrogen fuel power generation, or they can be a combination of multiple power generation systems. The total value of different power generation is fitted together, and its input power is always in a fluctuating state.

[0078] The EMS system collects power data from the grid in real time and adjusts the output power of the energy storage according to the actual load value, ensuring that there will be no overload or reverse flow under this architecture, while ensuring that the economic efficiency of energy storage is realized.

[0079] Let the grid input power of the energy storage system at the previous moment be A', the battery system output power be B', the load power requirement be C', the generator system input power be D', and the power sent by the EMS system be E'. At the current moment, the grid input power is A, the battery system output power is B, the load power requirement is C, the generator system input power is D, and the EMS system power is E. After optimization, the power sent by the EMS to the PCS at the current moment is E.

[0080] In an ideal scenario, as a load follower, the battery system outputs power to support the load, the grid power A needs to be 0, and the total power of the AC internal network needs to be 0, that is: A+B-C+D=0, A+B=CD, B=CD;

[0081] Please refer to Fig. 2 In the existing technology, in order to meet the load following requirement, the power output of the battery system at the current moment should be: B = E' = C' - D', that is, the battery power at the current moment = the power transmitted by EMS at the previous moment = the sum of the power of other devices;

[0082] But because C and D are changing in the actual use process, the current battery power should be B = E' = C' - D', that is, the current battery power B = the EMS issued power at the last moment, and the EMS issued power at the last moment = the sum of other devices at the last moment, the part of the current battery B output shortage will be supplemented by the power grid A or the excess power of B will flow back to the power grid;

[0083] To this end, a power following control method of an energy storage system is provided, specifically, it comprises:

[0084] According to the set load power approach coefficient and power margin parameter, the power issued by the EMS system to the PCS is adjusted.

[0085] Specifically, the battery output power B = E' = C' - D' at the next moment needs to be adjusted at the current moment, in order to meet the slow reaction speed of the power following requirement and gradually follow, but the fast reaction speed of the anti-flow requirement and immediately meet the power requirement, the strategy must be balanced in each scene, and the following optimization strategy is set according to the following optimization strategy:

[0086] When the EMS system issued power E' at the last moment >= 0 and the current grid input power A >= 0, the optimization power E" of the PCS issued by the EMS system at the current moment is ((C-D)-E') * λ + E', λ is a load power approach coefficient of 0-1, and the specific value is configured according to the project;

[0087] When the EMS issued power E' at the last moment >= 0 and the current grid power A < 0, the optimization power E" of the PCS issued by the EMS at the current moment is C-D-α, α is a power margin parameter greater than 0, which is configured according to the project;

[0088] When the EMS issued power E' at the last moment < 0 and the current grid power A < α + β, the optimization power E" of the PCS issued by the EMS at the current moment is E' + ((C-D)-α), α and β are power margin parameters greater than 0, wherein α is a load fluctuation related power margin parameter, and β is an AC power generation system related judgment threshold power margin parameter, which is configured according to the project;

[0089] When the EMS issued power E' at the last moment < 0 and the current grid power A >= α + β, the optimization power E" of the PCS issued by the EMS at the current moment is ((C'-D')-(C-D))*λ + E', λ is a load power approach coefficient of 0-1.

[0090] In the above optimization strategy, lambda is used to adjust the speed of the PCS power approaching the load, the greater the lambda, the faster the speed of approaching the load, the greater the lambda, the slower the speed of approaching the load, alpha and beta are used to ensure that the current PCS power is always greater than the reverse flow power, the difference between the actual demand power and the actual output power is close to the coefficient plus the actual power last time, which ensures that the power increases or decreases slowly approaches the actual demand power, the greater the lambda, the faster the approaching speed, the smaller, the approaching speed is slower and smoother; The greater the alpha, the more the remaining amount, the greater the reverse flow reserve, but the greater the power loss, the smaller, the smaller the remaining amount, and the smaller the power loss. The greater the beta, the less the system is prone to failure, but the greater the power loss, the smaller the system is prone to failure, but the smaller the power loss, so each parameter needs to be configured according to the actual project to achieve the most suitable effect. In this embodiment, lambda is specifically 0.5, alpha is specifically 10KW, and beta is specifically 5KW.

[0091] The optimization strategy can meet the power following requirement and the anti-reverse flow requirement.

[0092] Please refer to Fig. 3 Embodiment two of the present application is:

[0093] A power following control terminal 1 of an energy storage system, comprising a memory 3, a processor 2 and a computer program stored on the memory 3 and executable on the processor 2, and the processor 2 implements the method of the above-mentioned embodiment one when executing the computer program.

[0094] In summary, the present application provides a power following control method and terminal of an energy storage system, which optimizes the traditional peak clipping and valley filling strategy regulation, can meet the gradual following effect of power following requirement, and can prevent current reverse flow to the power grid. The energy storage system can regulate power in real time according to the EMS acquisition data, ensure that the energy storage power can be discharged, and increase the economic benefit of the use of the energy storage system.

[0095] The above-mentioned is only an embodiment of the present application, and does not limit the patent range of the present application, any equivalent transformation or direct or indirect application in related technical fields by using the content of the specification and drawings of the present application is also included in the patent protection range of the present application.

Claims

1. A method of power-follow control for an energy storage system, the method comprising: The method comprises the following steps: According to the preset load power approaching coefficient and power margin parameter, the historical power of the last moment issued by the EMS system to the PCS is corrected to obtain the optimized power, and the optimized power is issued to the PCS, specifically comprising: If the historical power E' >= 0 and the current grid power A >= 0, the power E'' issued by the EMS system to the PCS at this moment is ((C-D)-E') * lambda + E'; Wherein, C is the power required by the load at the current moment, D is the input power of the current AC power generation system, and lambda is the load power approaching coefficient; If the historical power E' >= 0 and the current grid power A < 0, the power E'' issued by the EMS system to the PCS at this moment is C-D-alpha; Wherein, alpha is the power margin parameter related to load fluctuation, alpha > 0; If the historical power E' < 0 and the current grid power A < alpha + beta, the power E'' issued by the EMS system to the PCS at this moment is according to the following formula: E'' = E' + ((C-D)-alpha); Wherein, beta is the judgment threshold power margin parameter related to the AC power generation system; If the historical power E' < 0 and the current grid power A >= alpha + beta, the power E'' issued by the EMS system to the PCS at this moment is according to the following formula: E'' = ((C'-D')-(C-D))*lambda + E'.

2. An energy storage system power follow control terminal comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein, The processor executes the computer program to realize the method of claim 1.

Images