Regulation and control method and system for improving regulation and control speed and precision of energy storage system

Abstract

The invention discloses a regulation and control method and system for improving the regulation and control speed and precision of an energy storage system, and the method comprises the following steps: obtaining the real-time power of commercial power through the CT sampling of an ammeter or a PCS; calculating the current mains supply power adjusting quantity based on the mains supply real-time power, and adjusting the mains supply power according to the current mains supply power adjusting quantity; and calculating a photovoltaic output power adjusting quantity based on the adjusted commercial power, and adjusting the photovoltaic output power according to the photovoltaic output power adjusting quantity. According to the invention, real-time scheduling of the PCS is realized directly according to the commercial power sampling information, and the problem of slow response caused by slow sampling time of other data is avoided; and meanwhile, the problem of PCS sampling power error caused by interference is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage systems, and in particular to a control method and system for improving the control speed and accuracy of an energy storage system. Background Art

[0002] In the energy storage system, there is a relationship: load power = mains power + PCS power + photovoltaic power. The dispatching logic of the energy storage system is generally based on the above formula to dispatch PCS and photovoltaic power. Among them, the mains power can be obtained from the meter, the PCS power can be obtained from the PCS, and the photovoltaic power can be obtained from the photovoltaic inverter and other equipment. The load power is calculated based on the above data (the cost of the meter is high, and the load is generally not connected to the meter separately for the use of load power). Since the dispatching needs to rely on the relationship reflected in the above formula, there are the following defects: (1) The dispatching speed is slow, because the mains power, PCS power, and photovoltaic power must be obtained at the same time to calculate the load power, and these three power values ​​must be obtained from three different devices. All three values ​​must be updated to calculate the accurate load power, and the processing speed is slow. In addition, the response speed of the photovoltaic inverter is slow, resulting in a slower dispatching speed. (2) The dispatching accuracy is lost. Since the load power needs to be obtained through calculation, if one of the samples has interference or a large error, it may cause load calculation errors, which in turn causes problems in the dispatching logic. The most common situation is when the PCS is in parallel. There is ripple interference between the parallel machines, which will cause slight fluctuations in the sampled power. If data processing is not performed, it may cause problems in the scheduling logic. Summary of the invention

[0003] The purpose of the present invention is to solve the problems in the prior art.

[0004] The technical solution adopted by the present invention to solve the technical problem is: to provide a control method for improving the control speed and accuracy of an energy storage system, comprising the following steps:

[0005] Obtain the real-time power of the mains through the electric meter or CT sampling of the PCS;

[0006] Calculate the current power regulation amount of the mains based on the real-time power of the mains, and adjust the mains power according to the current power regulation amount of the mains;

[0007] The photovoltaic output power adjustment amount is calculated based on the adjusted mains power, and the photovoltaic output power is adjusted according to the photovoltaic output power adjustment amount.

[0008] Preferably, the current power adjustment amount of the mains is calculated based on the real-time power of the mains, including two situations: the battery needs to be charged and the battery needs to be discharged;

[0009] When the battery needs to be charged, the current power regulation of the mains ΔPCS power is expressed as:

[0010] ΔPCS power = maximum utility power consumption - real-time utility power;

[0011] The maximum power consumption of the mains is ≤MIN (the maximum charging power of the battery, the input power limit of the mains circuit breaker);

[0012] Among them, the maximum battery charging power is the maximum allowable charging power provided by the battery, and the mains circuit breaker input limit power is the maximum allowable power value of the mains circuit breaker of this system;

[0013] When the battery needs to be discharged, the current power regulation amount ΔPCS of the mains is expressed as:

[0014] ΔPCS power = maximum grid-feeding power of the mains - real-time power of the mains;

[0015] The maximum grid power of the mains is ≤MIN (the maximum discharge power of the battery, the grid power limit);

[0016] Among them, the maximum discharge power of the battery is the maximum allowable discharge power of the battery under the current working condition; the feeder power limit is the maximum feeder power allowed by the system.

[0017] Preferably, the step of calculating the photovoltaic output power adjustment amount based on the adjusted mains power comprises the following steps:

[0018] Calculate the photovoltaic output power, expressed as:

[0019] PV output power = load power + PCS real-time power + grid-feeding limit power;

[0020] The photovoltaic output power is gradually adjusted using a smaller change rate until the required output power is reached.

[0021] Preferably, the smaller rate of change is 10% of the rated power of the mains or 10% of the ΔPCS power.

[0022] Preferably, the change rate satisfies the following conditions:

[0023] ΔPV power <= grid-feed limit power + load real-time power + mains real-time power.

[0024] Preferably, for an energy storage system including multiple PCSs, the current power regulation amount of the mains is allocated to each PCS according to the rated power ratio of each PCS, and each PCS adjusts its own power according to the allocated current power regulation amount of the mains.

[0025] Preferably, for an energy storage system including multiple photovoltaics, the photovoltaic output power adjustment amount is allocated to each photovoltaic according to the rated power ratio of each photovoltaic, and each photovoltaic adjusts its own output power according to the allocated photovoltaic output power adjustment amount.

[0026] The present invention also provides a control system for improving the control speed and accuracy of an energy storage system, comprising:

[0027] The mains power collection module obtains the real-time power of the mains power through the CT sampling of the electric meter or PCS

[0028] The mains side regulation module calculates the mains current power regulation amount based on the mains real-time power, and regulates the mains power according to the mains current power regulation amount;

[0029] The photovoltaic side regulation module calculates the photovoltaic output power regulation amount based on the regulated mains power, and regulates the photovoltaic output power according to the photovoltaic output power regulation amount.

[0030] The present invention also provides an electronic device, comprising:

[0031] one or more processors;

[0032] a storage device for storing one or more programs,

[0033] When the one or more programs are executed by the one or more processors, the one or more processors implement any of the above methods.

[0034] The present invention also provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, any of the above methods is implemented.

[0035] The present invention has the following beneficial effects:

[0036] (1) Fast response speed: PCS real-time scheduling is achieved directly based on the mains sampling information, avoiding the problem of slow response caused by slow sampling time of other data;

[0037] (2) High dispatching accuracy. No calculation is required. Closed-loop control is achieved directly using sampled data, which avoids the loss of accuracy in the software calculation of "load power = mains power + PCS power + photovoltaic power". At the same time, it avoids the problem of PCS sampling power error caused by interference.

[0038] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments, but the present invention is not limited to the embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 A method step diagram of an embodiment of the present invention;

[0040] Figure 2 A structural diagram of an energy storage system according to an embodiment of the present invention;

[0041] Figure 3is a system structure diagram of an embodiment of the present invention;

[0042] Figure 4 FIG. 4 is a hardware structure diagram of an electronic device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0043] See also Figure 1 FIG. 1 is a diagram showing steps of a method according to an embodiment of the present invention, comprising the following steps:

[0044] S101, obtain the real-time power of the mains through the electric meter or CT sampling of the PCS;

[0045] S102, calculating the current power adjustment amount of the mains based on the real-time power of the mains, and adjusting the power of the mains according to the current power adjustment amount of the mains;

[0046] S103, calculating a photovoltaic output power adjustment amount based on the adjusted mains power, and adjusting the photovoltaic output power according to the photovoltaic output power adjustment amount.

[0047] Specifically, the energy storage system structure diagram of the embodiment of the present invention is shown in Figure 2 As shown in the figure, users of energy storage systems are mainly concerned about two points: the power on the mains side and the power on the photovoltaic side. For the power on the mains side, pay attention to whether it is fed into the grid and whether it exceeds the circuit breaker limit on the mains side when using electricity to avoid circuit breaker tripping; for the power on the photovoltaic side, pay attention to whether photovoltaics are used to the maximum extent to achieve the maximum utilization rate of photovoltaics.

[0048] Based on these two concerns, combined with the problems of slow scheduling speed and loss of precision in the prior art, the present invention is proposed; in the embodiment of the present invention, since the PCS responds faster, it is responsible for the scheduling of larger step values; the photovoltaic response is slower, and it is responsible for the scheduling of smaller step values. By slowly increasing the photovoltaic power in small steps, the PCS power slowly decreases, thereby realizing the charging and discharging of the photovoltaic. The specific content of the technical solution of the embodiment of the present invention is described in points below.

[0049] a) Improve response speed and accuracy

[0050] Since photovoltaic response is slow, the scheduling speed needs to be improved, which can be solved by increasing the scheduling speed of PCS. The main reason for the slow PCS scheduling control in the prior art is that when the load changes, the load power cannot be obtained immediately. It is necessary to wait until the power of photovoltaic, mains, and PCS are stable before the load calculation is stable, so as to calculate how much more power the PCS needs to supplement the load or how much photovoltaic power the PCS needs to absorb for charging; therefore, to improve the scheduling speed of PCS, the load calculation process must be abandoned to reduce the impact of multiple terminals. The solution adopted in the embodiment of the present invention is to use the power on the mains side as the control target, and calculate the power that the PCS needs to supplement by monitoring the real-time power on the mains side. In addition, photovoltaics do not participate in scheduling during the rapid scheduling process, so photovoltaics are in a steady state process. The specific implementation is as follows:

[0051] When the battery needs to be charged, since photovoltaic power does not participate in the control at this stage, the charging power is only obtained from the mains side, so the scheduling can be achieved by controlling the power consumption of the mains, and then we can get (the power in the formula is an absolute value)

[0052] Maximum power consumption of the mains ≤ MIN (maximum battery charging power, input power limit of the mains circuit breaker) #(1)

[0053] Among them, the maximum battery charging power is the maximum allowable charging power provided by the battery, and the mains circuit breaker input limit power is the maximum allowable power value of the mains circuit breaker of this system. The current power that can be increased by the mains is:

[0054] ΔPCS power = maximum utility power consumption - real-time utility power #(2)

[0055] When the battery needs to be discharged, the photovoltaic power does not participate in the control at this stage, so the battery discharge power will be loaded first and then fed into the grid. Therefore, the scheduling can be achieved by controlling the grid feeding power, and the power in the formula can be obtained (the power in the formula is an absolute value)

[0056] Maximum grid power of mains ≤ MIN (maximum battery discharge power, grid power limit)#(3)

[0057] The maximum battery discharge power is the maximum allowable discharge power of the battery under the current working condition, and the grid feed limit power is the maximum grid feed power allowed by the system (it can be a set value or calculated according to the limit value of the circuit breaker, which is related to the system configuration)

[0058] The power that can be increased by the mains is:

[0059] ΔPCS power = maximum grid power - real-time grid power #(4)

[0060] For example, the current grid power limit is 10KW, the actual mains power consumption is 5KW, the maximum allowable battery discharge is 30KW, and the battery is fully charged, then: ΔPCS power = grid power limit (10KW) + mains power consumption (5KW) = 15KW.

[0061] b) Photovoltaic supplementary loading and charging

[0062] Under the premise of realizing the fast dispatch in a), the output power of photovoltaic is controlled. Photovoltaic power = load power + PCS power + grid feed limit power, where the grid feed limit power is the maximum grid feed power allowed by the system (can be a set value or calculated according to the limit value of the circuit breaker, which is related to the system configuration). The load is a variable that changes unpredictably in real time. In order to reduce the power fluctuation in a) caused by photovoltaic power dispatch, the increase of photovoltaic power needs to adopt a smaller change rate, such as each step is 10% of the PCS rated power or ΔPCS power. For example: if the ΔPCS power calculated in step 2 is 15KW, then the Δ photovoltaic power can be 10% of 15KW, that is, 1.5KW. And the Δ photovoltaic power satisfies:

[0063] ΔPV power <= grid-feeding limit power + load real-time power + PCS real-time power#(5)

[0064] Although the real-time load power here is also calculated by "load power = mains power + PCS power + photovoltaic power", since this step adopts small step scheduling, it has little impact on the accuracy.

[0065] c) Parallel power distribution

[0066] The ΔPCS power and ΔPV power calculated in a) and b) are distributed according to the percentage of the rated power of each PCS and each PV in the parallel system to the total system power.

[0067] In the embodiment of the present invention, there are multiple PVs and multiple PCSs. The above-mentioned ΔPCS power and ΔPV power can be allocated according to the rated power of each PCS and PV. For example: the ΔPCS power is 15KW, the ΔPV power is 1.5KW, and 3 PCS and PV are connected in parallel. The rated power of PCS1 is 5KW, the rated power of PCS2 is 15KW, and the rated power of PCS3 is 30KW. Then the power of ΔPCS1 is 1.5KW, the power of ΔPCS2 is 4.5KW, and the power of ΔPCS3 is 9KW. The rated power of PV is 10KW, 10KW, and 30KW respectively. Then the power of ΔPV 1 is 0.3KW, the power of ΔPV 2 is 0.3KW, and the power of ΔPV 3 is 0.9KW.

[0068] See also Figure 3 FIG. 1 is a system structure diagram of an embodiment of the present invention, including:

[0069] The mains power collection module 301 obtains the real-time power of the mains power through the CT sampling of the electric meter or PCS

[0070] The mains side regulation module 302 calculates the mains current power regulation amount based on the mains real-time power, and regulates the mains power according to the mains current power regulation amount;

[0071] The photovoltaic side regulation module 303 calculates the photovoltaic output power regulation amount based on the regulated mains power, and regulates the photovoltaic output power according to the photovoltaic output power regulation amount.

[0072] See also Figure 4 As shown, it is a hardware structure diagram of an electronic device of an embodiment of the present invention, including: a processor 401 and a memory 402; wherein the memory 402 is used to store computer-executable instructions; the processor 401 is used to execute the computer-executable instructions stored in the memory to implement each step performed by the electronic device in the above embodiment. For details, please refer to the relevant description in the above method embodiment.

[0073] Optionally, the memory 402 may be independent or integrated with the processor 401 .

[0074] When the memory 402 is independently provided, the electronic device further includes a bus 403 for connecting the memory 402 and the processor 401 .

[0075] An embodiment of the present invention further provides a computer storage medium, in which computer execution instructions are stored. When a processor executes the computer execution instructions, the above method is implemented.

[0076] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions described in the above embodiments may still be modified, or some or all of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A control method for improving the control speed and accuracy of an energy storage system, characterized in that: The following steps are involved: Obtain the real-time power of the mains through the electric meter or CT sampling of the PCS; Calculate the current power regulation amount of the mains based on the real-time power of the mains, and adjust the mains power according to the current power regulation amount of the mains; The photovoltaic output power adjustment amount is calculated based on the adjusted mains power, and the photovoltaic output power is adjusted according to the photovoltaic output power adjustment amount.

2. The control method for improving the control speed and accuracy of the energy storage system according to claim 1, characterized in that: The current power adjustment amount of the mains is calculated based on the real-time power of the mains, including two situations where the battery needs to be charged and the battery needs to be discharged; When the battery needs to be charged, the current power regulation of the mains ΔPCS power is expressed as: ΔPCS power = maximum utility power consumption - real-time utility power; The maximum power consumption of the mains is ≤MIN (the maximum charging power of the battery, the input power limit of the mains circuit breaker); Among them, the maximum battery charging power is the maximum allowable charging power provided by the battery, and the mains circuit breaker input limit power is the maximum allowable power value of the mains circuit breaker of this system; When the battery needs to be discharged, the current power regulation amount ΔPCS of the mains is expressed as: ΔPCS power = maximum grid-feeding power of the mains - real-time power of the mains; The maximum grid power of the mains is ≤MIN (the maximum discharge power of the battery, the grid power limit); Among them, the maximum discharge power of the battery is the maximum allowable discharge power of the battery under the current working condition; the feeder power limit is the maximum feeder power allowed by the system.

3. The control method for improving the control speed and accuracy of the energy storage system according to claim 1, characterized in that: The step of calculating the photovoltaic output power adjustment amount based on the adjusted mains power comprises the following steps: Calculate the output power of photovoltaic, expressed as: PV output power = load power + PCS real-time power + grid-feeding limit power; The photovoltaic output power is gradually adjusted using a smaller change rate until the required output power is reached.

4. The control method for improving the control speed and accuracy of the energy storage system according to claim 3, characterized in that: The smaller change rate is 10% of the rated power of the utility power or 10% of the ΔPCS power.

5. The control method for improving the control speed and accuracy of the energy storage system according to claim 3, characterized in that: The change rate meets the following conditions: ΔPV power <= grid-feed limit power + load real-time power + mains real-time power.

6. The control method for improving the control speed and accuracy of the energy storage system according to claim 1, characterized in that: For an energy storage system including multiple PCSs, the current power regulation amount of the mains is allocated to each PCS according to the rated power ratio of each PCS, and each PCS adjusts its own power according to the allocated current power regulation amount of the mains.

7. The control method for improving the control speed and accuracy of the energy storage system according to claim 1, characterized in that: For an energy storage system including multiple photovoltaics, the photovoltaic output power adjustment amount is allocated to each photovoltaic according to the rated power ratio of each photovoltaic, and each photovoltaic adjusts its own output power according to the allocated photovoltaic output power adjustment amount.

8. A control system for improving the control speed and accuracy of an energy storage system, characterized in that: include: The mains power collection module obtains the real-time power of the mains power through the CT sampling of the electric meter or PCS The mains side regulation module calculates the mains current power regulation amount based on the mains real-time power, and regulates the mains power according to the mains current power regulation amount; The photovoltaic side regulation module calculates the photovoltaic output power regulation amount based on the regulated mains power, and regulates the photovoltaic output power according to the photovoltaic output power regulation amount.

9. An electronic device, comprising: one or more processors; a storage device for storing one or more programs, When the one or more programs are executed by the one or more processors, the one or more processors implement the method according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

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