A dynamic self-adaptive control method for preventing reverse power of an energy storage system

Abstract

The present application relates to the technical field of energy storage system control, and discloses a kind of energy storage system anti-reverse power dynamic self-adaptive control method, comprising: using EMS to collect the real-time data of anti-reverse power device, the real-time data is sequentially stored in EMS according to time, forms historical load curve;EMS calculates the peak-peak value of T time range according to historical load curve, forms peak-peak value sequence, and takes the maximum value in the peak-peak value sequence as value Pmaxt;According to value Pmaxt, the reverse power action setting value of anti-reverse power device calculates EMS anti-reverse power threshold;The EMS anti-reverse power threshold is compared with the rated power of household gate side, to dynamically adjust the EMS anti-reverse power threshold.The present application realizes the anti-reverse power control of gateway side power, so that power is not more than anti-reverse power device trip setting value, will not trip, thereby guaranteeing the continuity of user electricity, energy storage system discharge.

Description

Technical Field

[0001] This invention relates to the field of energy storage system control technology, and in particular to a dynamic adaptive control method for reverse power in energy storage systems. Background Technology

[0002] Currently, small-scale industrial and commercial energy storage systems are generally connected to the power grid through user distribution substations. A major profit model is peak shaving and valley filling: charging the energy storage during periods of low electricity prices and discharging the energy storage to the user's load when electricity prices are high, profiting from the price difference between charging and discharging. When the total load power under the substation is equivalent to the maximum discharge power of the energy storage, it may lead to some electricity being fed back to the power grid. Currently, power supply companies in various regions have successively introduced policies to prohibit users from feeding energy storage devices back to the power grid.

[0003] To address the aforementioned issues, a reverse power protection device is installed at the user's inlet gate. This device senses the power of the electrical energy flowing through the inlet gate and trips the user's inlet switch when the power is less than a set value for a certain period of time. While this method can avoid fines from the power supply company due to power backflow caused by reduced load, sudden power outages will result in significant economic losses for the company's production and operation, as well as the discharge revenue of the energy storage system. Summary of the Invention

[0004] This invention provides a dynamic adaptive control method for reverse power in energy storage systems, which minimizes the economic losses to users and the loss of energy storage discharge revenue caused by power outages in existing technologies.

[0005] This invention provides a dynamic adaptive control method for reverse power protection in an energy storage system. The method is based on an energy storage system connected to a reverse power protection device and a power grid. The reverse power protection device is connected to a service access point on the power grid, and the service access point is connected to a user load. The method specifically includes:

[0006] Real-time data from the reverse power protection device is collected using an EMS, and the real-time data is stored sequentially in the EMS according to time to form a historical load curve;

[0007] EMS calculates the peak-to-peak value Pvppt over a time range of T based on historical load curves, forms a peak-to-peak value sequence, and takes the maximum value in the peak-to-peak value sequence as the value Pmaxt.

[0008] Calculate the EMS reverse power threshold EmsPrset based on the value Pmaxt and the reverse power action setting value DevPrset of the reverse power protection device.

[0009] The EMS reverse power threshold EmsPrset is compared with the rated power Pe at the inlet gate to dynamically adjust the EMS reverse power threshold EmsPrset.

[0010] Furthermore, the energy storage system includes an energy management system device (EMS) and an energy storage system charge / discharge regulation device (PCS). The energy management system device (EMS) is connected to the anti-reverse power device and the energy storage system charge / discharge regulation device (PCS), and the energy storage system charge / discharge regulation device (PCS) is connected to the power grid.

[0011] Further, the step of the EMS calculating the peak-to-peak value Pvppt over a time range T based on historical load curves, forming a peak-to-peak value sequence, and taking the maximum value in the peak-to-peak value sequence as the value Pmaxt includes:

[0012] Starting from midnight each day, the peak-to-peak value within a time range of T minutes is calculated every T minutes. The peak-to-peak value is calculated as the difference between the maximum power value Pmax and the minimum power value Pmin at the entrance gate within the time range of T, i.e., Pvppt = Pmax - Pmin; where T is a pre-set value and the unit is minutes.

[0013] The peak-to-peak sequence is formed as: Pvppt0, Pvppt1, Pvppt2, ..., and the maximum value in the peak-to-peak sequence is taken as the value Pmaxt.

[0014] Furthermore, in the step of calculating the EMS reverse power threshold EmsPrset based on the value Pmaxt and the reverse power action setting value DevPrset of the reverse power protection device, the calculation formula is as follows:

[0015] EmsPrset=n*Pmaxt+DevPrset+Pdlt

[0016] Where n takes values ​​in the range of [1.2, 2.0], and Pdlt is taken as 1.5 times the control accuracy k of the PCS of the energy storage system's charge and discharge regulation equipment, that is, Pdlt = Ppcs * k * 1.5, where Ppcs is the rated power generation of the energy storage system.

[0017] Further, the step of comparing the EMS reverse power threshold EmsPrset with the rated power Pe at the inlet gate to dynamically adjust the EMS reverse power threshold EmsPrset includes:

[0018] If the EMS reverse power threshold EmsPrset is greater than 10% of the rated power Pe at the inlet gate, then the adjustment value EmsPrset = Pe * 10%;

[0019] Further, after the step of comparing the EMS reverse power threshold EmsPrset with the rated power Pe at the inlet gate to dynamically adjust the EMS reverse power threshold EmsPrset, the method further includes:

[0020] Let P0 be the real-time power at the inlet gate, Ppcs0 be the real-time power of the energy storage system, Ppcs1 be the power that the energy storage system should generate at the next moment, and Ppcsmax be the maximum power that the energy storage system can currently generate.

[0021] Calculate the power output Ppcs1 that the energy storage system should generate at the next moment; the calculation formula is as follows:

[0022] Ppcs1 = Ppcs0 + P0 - EmsPrset;

[0023] If Ppcs1≥Ppcsmax, then Ppcs1=Ppcsmax; if Ppcs1≤0, then Ppcs1=0.

[0024] The beneficial effects of this invention are as follows:

[0025] The method provided by this invention dynamically tracks the power at the inlet gate. From setting the reverse power control threshold to real-time tracking, everything is dynamically changing, which can adapt to various user scenarios and form a customized solution. It avoids difficult and rigid manual settings, dynamically adjusts the discharge limit of the energy storage system, greatly reduces the probability of users tripping and losing power due to reverse power, and increases the return on investment of the energy storage system. Attached Figure Description

[0026] Figure 1 This is a flowchart illustrating the reverse power dynamic adaptive control method for the energy storage system of the present invention.

[0027] Figure 2 This is a topology diagram showing the relationship between the inlet gate, the energy storage system, and the user load in this invention.

[0028] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0029] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0030] This invention provides a method for dynamically and adaptively adjusting the power output of an energy storage system by tracking the power at the inlet gate under fluctuating user load conditions. Based on an energy storage system, such as... Figure 2As shown, the energy storage system is connected to the anti-reverse power device and the power grid. The anti-reverse power device is connected to the inlet gate on the power grid. The inlet gate is connected to the user's load and can also be connected to the user's distribution transformer. The energy storage system includes an energy management system (EMS) and an energy storage system charge / discharge regulation device (PCS). The EMS is connected to both the anti-reverse power device and the PCS. The PCS is connected to the power grid.

[0031] like Figure 1 As shown, the energy storage system reverse power dynamic adaptive control method provided by this invention collects data from the reverse power protection device or electricity meter installed at the inlet gate, adjusts the reverse power protection threshold in real time, tracks the power at the inlet gate, and realizes a dynamic reverse power protection method, specifically including:

[0032] S1. Real-time data of the anti-reverse power device is collected using EMS. The real-time data is stored in EMS in chronological order to form a historical load curve.

[0033] S2, EMS calculates the peak-to-peak value Pvppt for the time range T based on the historical load curve, forms a peak-to-peak value sequence, and takes the maximum value in the peak-to-peak value sequence as the value Pmaxt;

[0034] EmsPrset is the EMS reverse power threshold, DevPrset is the reverse power action setting value of the reverse power protection device, Pe is the rated power at the inlet gate, and Ppcs is the rated power generation of the energy storage system.

[0035] S21. Starting from midnight every day, calculate the peak-to-peak value within a time range of T minutes. The peak-to-peak value is calculated as the difference between the maximum power value Pmax and the minimum power value Pmin at the entrance gate within the time range of T, i.e., Pvppt = Pmax - Pmin; where T is a pre-set value and the unit is minutes.

[0036] S22. The peak-to-peak sequence is formed as: Pvppt0, Pvppt1, Pvppt2..., and the maximum value in the peak-to-peak sequence is taken as the value Pmaxt.

[0037] S3. Calculate the EMS reverse power threshold EmsPrset based on the value Pmaxt and the reverse power action setting value DevPrset of the reverse power protection device. The EMS reverse power threshold is dynamically adjusted to reduce discharge limitation losses caused by a single threshold. The formula for calculating the EMS reverse power threshold EmsPrset is:

[0038] EmsPrset=n*Pmaxt+DevPrset+Pdlt

[0039] Where n takes values ​​in the range of [1.2, 2.0], and Pdlt is taken as 1.5 times the control accuracy k of the PCS of the energy storage system's charge and discharge regulation equipment, that is, Pdlt = Ppcs * k * 1.5, where Ppcs is the rated power generation of the energy storage system.

[0040] S4. Compare the EMS reverse power threshold EmsPrset with the rated power Pe at the inlet gate to dynamically adjust the EMS reverse power threshold EmsPrset.

[0041] If the EMS reverse power threshold EmsPrset is greater than 10% of the rated power Pe at the inlet gate, then the adjustment value EmsPrset = Pe * 10%;

[0042] S5. By tracking the power at the inlet gate in real time, the output of the energy storage system can be adjusted without detecting the user's load power consumption, thus saving equipment procurement and installation costs.

[0043] Let P0 be the real-time power at the inlet gate, Ppcs0 be the real-time power of the energy storage system, Ppcs1 be the power that the energy storage system should generate at the next moment, and Ppcsmax be the maximum power that the energy storage system can generate at present.

[0044] S51. Calculate the power output Ppcs1 of the energy storage system at the next moment; where the calculation formula is: Ppcs1=Ppcs0+P0-EmsPrset;

[0045] S52. If Ppcs1≥Ppcsmax, then Ppcs1=Ppcsmax; if Ppcs1≤0, then Ppcs1=0.

[0046] This invention uses an EMS to collect real-time data from the reverse power protection device. The real-time data is stored in the EMS sequentially according to time to form a historical load curve. Based on the statistical results of the historical load curve, the EMS dynamically generates an EMS reverse power protection threshold. According to the threshold and the real-time data of the reverse power protection device, the discharge power of the energy storage system is controlled to track the power change at the inlet gate, thereby realizing reverse power protection control of the gate side power. This ensures that the power backflow does not exceed the tripping set value of the reverse power protection device and will not trip, thus guaranteeing the continuity of user electricity consumption and energy storage system discharge.

[0047] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, apparatus, article, or method that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, apparatus, article, or method. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, apparatus, article, or method that includes that element.

[0048] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A dynamic adaptive control method for reverse power in an energy storage system, characterized in that, The method is based on an energy storage system, which is connected to an anti-reverse power device and the power grid. The anti-reverse power device is connected to the grid's inlet gate, and the inlet gate is connected to user loads. Specifically, the method includes: Real-time data from the reverse power protection device is collected using an EMS, and the real-time data is stored sequentially in the EMS according to time to form a historical load curve; EMS calculates the peak-to-peak value Pvppt over a time range of T based on historical load curves, forming a peak-to-peak value sequence, and takes the maximum value in the sequence as the value Pmaxt. Specifically, starting from midnight each day, the peak-to-peak value is calculated every T minutes. The peak-to-peak value is calculated as the difference between the maximum power value Pmax and the minimum power value Pmin at the inlet gate within the T time range, i.e., Pvppt = Pmax - Pmin. Here, T is a pre-set value in minutes. The resulting peak-to-peak value sequence is: Pvppt0, Pvppt1, Pvppt2, ..., and the maximum value in the sequence is taken as the value Pmaxt. The EMS reverse power threshold EmsPrset is calculated based on the value Pmaxt and the reverse power action setting value DevPrset of the reverse power protection device. The calculation formula is: EmsPrset=n*Pmaxt+DevPrset+Pdlt; where n takes the value range of [1.2,2.0], and Pdlt is taken as 1.5 times the control accuracy k of the PCS of the energy storage system charging and discharging regulation equipment, that is, Pdlt=Ppcs*k*1.5, where Ppcs is the rated power generation of the energy storage system. The EMS reverse power threshold EmsPrset is compared with the rated power Pe at the inlet gate to dynamically adjust the EMS reverse power threshold EmsPrset. Let P0 be the real-time power at the inlet gate, Ppcs0 be the real-time power of the energy storage system, Ppcs1 be the power that the energy storage system should generate at the next moment, and Ppcsmax be the maximum power that the energy storage system can currently generate. Calculate the power Ppcs1 that the energy storage system should generate at the next moment. The calculation formula is: Ppcs1 = Ppcs0 + P0 - EmsPrset. If Ppcs1 ≥ Ppcsmax, then Ppcs1 = Ppcsmax; if Ppcs1 ≤ 0, then Ppcs1 = 0.

2. The energy storage system anti-reverse power dynamic adaptive control method according to claim 1, characterized in that, The energy storage system includes an energy management system (EMS) and a charge / discharge regulation device (PCS). The EMS is connected to the anti-reverse power device and the PCS, respectively. The PCS is connected to the power grid.

3. The energy storage system anti-reverse power dynamic adaptive control method according to claim 1, characterized in that, The step of comparing the EMS reverse power threshold EmsPrset with the rated power Pe at the inlet gate to dynamically adjust the EMS reverse power threshold EmsPrset includes: If the EMS reverse power threshold EmsPrset is greater than 10% of the rated power Pe at the inlet gate, then the adjustment value EmsPrset = Pe * 10%.

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