Energy storage system and method for rural power grid

Abstract

The application discloses a power storage system for a rural power grid and a method thereof, and belongs to the technical field of power storage systems.The power storage system comprises the following steps: step 1, collecting operation parameters of energy storage batteries of the power storage system for the rural power grid and load power of the rural power distribution network and transmitting the operation parameters and the load power to a master station control unit; step 2, performing risk judgment on the energy storage batteries according to the operation parameters by the master station control unit; step 3, generating a control instruction according to a result of the risk judgment by the master station control unit; and step 4, performing a control charging and discharging action according to the control instruction by the master station control unit. The power storage system overcomes the overcharging and overdischarging defects that are prone to occurring in the existing power storage method for the rural power grid, realizes accurate control on a power storage process, prolongs the service life of the energy storage batteries, improves the safety, stability and economy of system operation, and adapts to the demand of in-situ access and consumption of new energy of the rural power grid.

Description

Technical Field

[0001] This invention belongs to the technical field of energy storage systems, specifically relating to an energy storage system and method for rural power grids. Background Technology

[0002] With the development of the rural economy and the improvement of living standards, the demand for electricity in rural areas continues to grow. At the same time, rural areas possess abundant distributed wind power and other renewable energy resources. Vigorously developing and utilizing these new energy sources is a crucial measure for building a new power system and achieving green and low-carbon energy development. Currently, connecting new energy power generation to the rural power grid using equipment such as wind power storage poles mentioned in the technical solution with patent publication number "CN221978615U," and combining this with energy storage systems to achieve energy storage and local consumption, has become an important way to solve the problem of new energy access to rural power grids.

[0003] However, existing energy storage methods for rural power grids have significant drawbacks: rural power grid loads are characterized by their dispersed and highly fluctuating nature, and the output power of new energy generation (such as wind power) is unstable due to natural conditions, making it difficult to accurately match charging and discharging demands during energy storage. Traditional energy storage methods often use fixed thresholds or simple logic to control charging and discharging, lacking dynamic adaptation to changes in battery operating status and grid load, frequently resulting in overcharging or over-discharging of the energy storage batteries. Overcharging leads to electrolyte decomposition and capacity decay, and in severe cases, thermal runaway, posing safety hazards; over-discharging increases internal resistance and shortens cycle life, similarly affecting battery performance and safety. These problems not only reduce the lifespan of energy storage batteries and increase maintenance costs, but also may cause safety accidents such as fires and electric shocks, hindering the efficient utilization and sustainable development of new energy sources in rural power grids.

[0004] Therefore, there is an urgent need for an energy storage system and method for rural power grids that can precisely control the charging and discharging process, avoid overcharging and over-discharging, and balance battery life and operational safety. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention proposes an energy storage system and method for rural power grids. This system overcomes the overcharging and over-discharging defects that are common in existing energy storage methods for rural power grids, achieves precise control over the energy storage process, extends the lifespan of energy storage batteries, and improves the safety, stability, and economy of system operation. It also meets the needs of local access and consumption of new energy sources in rural power grids.

[0006] The present invention employs the following technical solution.

[0007] A method for storing electrical energy in rural power grids, comprising:

[0008] Step 1: Collect the operating parameters of the energy storage battery pack of the energy storage system for rural power grids and the load power of rural distribution networks and transmit them to the main station control unit;

[0009] Step 2: The main station control unit performs risk assessment based on the operating parameters of the energy storage battery pack;

[0010] Step 3: The main station control unit generates control commands based on the risk assessment results;

[0011] Step 4: The main station control unit controls the charging and discharging actions according to the control commands.

[0012] Preferably, step 1 specifically includes:

[0013] After the energy storage system for rural power grids is activated, the battery protection unit collects data on the energy storage battery pack, including battery voltage, in real time. Battery current Battery temperature and remaining battery power The operating parameters of the three-phase electricity meter are used to collect the load power of the rural power distribution network. The communication module transmits this data to the main station control unit in real time; simultaneously, the main station control unit obtains the power supply of the rural power distribution network. Battery health status of energy storage battery packs .

[0014] Preferably, step 2 specifically includes:

[0015] The main station control unit analyzes battery operating parameters using improved overcharge protection and over-discharge protection algorithms to assess risks.

[0016] Preferably, in step 2, the improved overcharge protection algorithm includes:

[0017] Computational Dynamics SOC Overcharge threshold The calculation formula is as follows: ,in As the basis for setting SOC Overcharge threshold, This is the set charging temperature correction factor. For the MAX function, The set optimal operating temperature for the battery;

[0018] Calculate the dynamic battery voltage overcharge threshold The calculation formula is as follows:

[0019] ,in The set base battery voltage overcharge threshold, The set charging power correction factor. The rated charging power of the energy storage battery pack. For the MIN function, For charging power, That is The product value given that its value is greater than zero. For the MAX function, This is the set voltage-temperature correction factor.

[0020] Preferably, in step 2, the improved over-discharge protection algorithm includes:

[0021] Computational Dynamics SOC Over-discharge threshold The calculation formula is as follows:

[0022] ,in As the basis for setting SOC Over-discharge threshold, This is the set discharge temperature correction factor. The value range can be set to 0.3~0.8;

[0023] Calculate the dynamic battery voltage over-discharge threshold The calculation formula is as follows: ,in The set base battery voltage over-discharge threshold, The set discharge power correction factor, For discharge power, That is The product value under the condition that its value is less than zero. This refers to the rated discharge power of the energy storage battery pack. This is the set temperature correction factor for the discharge voltage.

[0024] Preferably, in step 2, the method for risk assessment includes:

[0025] when SOC ≥ or ≥ At that time, it was determined that there was a risk of overcharging; when SOC ≤ or ≤ At that time, it was determined that there was a risk of over-releasing.

[0026] Preferably, step 3 specifically includes:

[0027] If there is no risk of overcharging or over-discharging, the main station control unit calculates the target charging and discharging power using a dynamic charging and discharging power adjustment algorithm. The calculation formula is:

[0028] ;

[0029] in, The remaining power adjustment coefficient is set; This is the load balancing adjustment coefficient; The set target remaining battery power.

[0030] If the battery temperature exceeds the optimal operating range, the target charge / discharge power will be affected. Temperature correction is performed to achieve the final target charge / discharge power. :

[0031] ;

[0032] in, The set temperature correction factor;

[0033] If the battery temperature does not exceed the optimal operating range This is the final target charging and discharging power, from which a power adjustment command containing the final target charging and discharging power is generated;

[0034] If there is a risk of overcharging, a stop charging command is generated; if there is a risk of over-discharging, a stop discharging command is generated. The stop charging command, stop discharging command, and power adjustment command are all control commands.

[0035] Preferably, step 4 specifically includes:

[0036] The master station control unit transmits control commands to the energy storage converter. If the control command is a power adjustment command, the energy storage converter adjusts the charging and discharging power to the final target charging and discharging power in the power adjustment command. If the control command is a stop charging command, the energy storage converter stops charging. If the control command is a stop discharging command, the energy storage converter stops discharging.

[0037] An energy storage system for rural power grids includes:

[0038] The system includes a wind power energy storage pole unit, a master station control unit, and a battery protection unit; both the wind power energy storage pole unit and the battery protection unit are communicatively connected to the master station control unit.

[0039] Wind power energy storage pole units include battery energy storage modules installed on the pole body;

[0040] The battery protection unit is used to collect the operating parameters of the energy storage battery pack of the battery energy storage module in real time. The operating parameters of the energy storage battery pack include the battery voltage, battery current, battery temperature and remaining battery capacity.

[0041] The main station control unit is used to receive the operating parameters of the energy storage battery pack transmitted by the battery protection unit and the load data of the rural power grid collected and transmitted by the three-phase metering meter. Based on the preset improved overcharge protection algorithm, improved over-discharge protection algorithm and dynamic charging and discharging power adjustment algorithm, it generates corresponding control commands.

[0042] The improved overcharge protection algorithm includes:

[0043] Computational Dynamics SOC Overcharge threshold The calculation formula is as follows: ,in The set base SOC overcharge threshold, This is the set charging temperature correction factor. For the MAX function, The set optimal operating temperature for the battery;

[0044] Calculate the dynamic battery voltage overcharge threshold The calculation formula is as follows:

[0045] ,in The set base battery voltage overcharge threshold, The set charging power correction factor. The rated charging power of the energy storage battery pack. For the MIN function, For charging power, That is The product value given that its value is greater than zero. For the MAX function, This is the set voltage-temperature correction factor;

[0046] Improved over-discharge protection algorithms include:

[0047] Computational Dynamics SOC Over-discharge threshold The calculation formula is as follows:

[0048] ,in As the basis for setting SOC Over-discharge threshold, This is the set discharge temperature correction factor. The value range can be set to 0.3~0.8;

[0049] Calculate the dynamic battery voltage over-discharge threshold The calculation formula is as follows: ,in The set base battery voltage over-discharge threshold, The set discharge power correction factor, For discharge power, That is The product value under the condition that its value is less than zero. This refers to the rated discharge power of the energy storage battery pack. This is the set temperature correction factor for the discharge voltage.

[0050] Preferably, the battery energy storage module includes an energy storage battery pack, an energy storage converter, a battery management unit, and a three-phase meter.

[0051] Preferably, the battery protection unit includes a voltage sensor, a current sensor, a temperature sensor, and a [other sensor] connected to the energy storage battery pack. SOC Sensors, including a current sensor connected in series between the energy storage battery pack and the energy storage converter, and voltage, current, and temperature sensors, are also present. SOC The sensors are used to collect data on the battery voltage, battery current, battery temperature, and remaining battery power of the energy storage battery pack.

[0052] The beneficial effects of the present invention are as follows, compared with the prior art:

[0053] Avoiding overcharging and over-discharging to extend battery life: The battery protection unit monitors battery operating parameters in real time, combining overcharge and over-discharge protection algorithms with dynamic charge / discharge power adjustment algorithms to precisely control the start / stop and power of charging and discharging, effectively preventing damage to the battery from overcharging and over-discharging. Experimental verification shows that using the storage method of this invention can extend the cycle life of energy storage batteries by more than 30%, reduce the battery capacity decay rate by 40%, and significantly reduce battery replacement costs.

[0054] Enhancing system operational safety: Multiple protection mechanisms are implemented, including parameter threshold protection and temperature correction protection, to promptly mitigate safety risks such as thermal runaway and fires caused by overcharging and over-discharging. Furthermore, the use of ultra-high-performance concrete poles and the balanced control of the battery management unit further improve the overall structural and electrical safety of the system, reducing the system failure rate by more than 60%.

[0055] Adapting to the characteristics of rural power grids and optimizing energy utilization: The dynamic charging and discharging power regulation algorithm fully considers the characteristics of rural power grid load dispersion, volatility, and unstable renewable energy generation. It can adjust the charging and discharging strategy in real time according to changes in grid supply and demand and battery status, achieving local consumption of renewable energy and grid load balance. Practical application tests have shown that the renewable energy consumption rate of rural power grids has increased by more than 25%, and the grid load fluctuation has decreased by 30%, effectively alleviating the power supply pressure on rural power grids.

[0056] Stable and reliable operation with low maintenance costs: The system adopts dual-mode communication and high-precision acquisition modules, ensuring stable data transmission and accurate parameter monitoring; the intelligent control of the main station control unit reduces manual intervention, and maintenance personnel can remotely monitor the system's operating status through the data monitoring platform and promptly handle alarm information, reducing maintenance costs by more than 50%, making it suitable for rural power grid maintenance scenarios. Attached Figure Description

[0057] Figure 1 This is an overall flowchart of the energy storage method for rural power grids described in this invention;

[0058] Figure 2 This is a schematic diagram of the energy storage system for rural power grids described in this invention. Detailed Implementation

[0059] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of this invention. The embodiments described in this application are merely some embodiments of this invention, and not all embodiments. Based on the spirit of this invention, any other embodiments obtained by those skilled in the art without creative effort are all within the protection scope of this invention.

[0060] like Figure 1 As shown, the present invention provides a method for energy storage in rural power grids, comprising:

[0061] Step 1: Collect the operating parameters of the energy storage battery pack of the energy storage system for rural power grids and the load power of rural distribution networks and transmit them to the main station control unit;

[0062] In a preferred but non-limiting embodiment of the present invention, step 1 specifically includes:

[0063] After the energy storage system for rural power grids is activated, the battery protection unit collects data on the energy storage battery pack, including battery voltage, in real time. Battery current Battery temperature and remaining battery power The operating parameters of the three-phase electricity meter are used to collect the load power of the rural power distribution network. The communication module transmits this data to the main station control unit in real time; simultaneously, the main station control unit obtains the power supply of the rural power distribution network. Battery health status of energy storage battery packs .

[0064] The main station control unit obtains the power supply of the rural power distribution network. The method is as follows:

[0065] At the node of the rural distribution network branch line where the wind power storage pole unit is connected (preferably behind the branch line switch, near the load concentration area), a power sensor connected to the main station control unit is deployed. The power value collected by the power sensor is the power supply power of the rural distribution network. And transmit it to the main station control unit.

[0066] The main station control unit obtains the battery health status of the energy storage battery pack. The method is as follows:

[0067] The energy storage battery pack is also connected to SOH sensor, SOH The sensor is connected to the main station control unit for communication. SOH Sensors collect data on the battery health status of the energy storage battery pack. And transmit it to the main station control unit.

[0068] Step 2: The main station control unit performs risk assessment based on the operating parameters of the energy storage battery pack;

[0069] In a preferred but non-limiting embodiment of the present invention, step 2 specifically includes:

[0070] The main station control unit analyzes battery operating parameters using improved overcharge protection and over-discharge protection algorithms to assess risks.

[0071] Existing overcharge and over-discharge protection algorithms rely solely on a single logical judgment based on remaining charge and voltage thresholds, which has the following drawbacks:

[0072] Dynamic changes were not considered: the effects of charging / discharging power and battery temperature on the remaining capacity were ignored. SOC The dynamic coupling relationship between the battery voltage and the battery voltage. For example, during high-power charging, the battery voltage may momentarily surge to near the threshold, but at this time... SOC If the upper limit is not reached, directly judging the risk of overcharging will lead to charging interruption and affect energy storage efficiency; in low temperature environment, the battery voltage characteristics change and the static voltage threshold cannot be adapted, which is prone to misjudgment.

[0073] Lack of delay and gradient judgment: Risk is determined solely by whether a single parameter meets the standard, without excluding false triggers caused by measurement errors and instantaneous fluctuations. For example, a sudden change in grid voltage may cause the battery voltage to briefly exceed the threshold; direct shutdown would be overprotection and affect system stability.

[0074] Battery health status not associated: Health parameters such as battery cycle count and internal resistance changes are not considered. SOH Adjusting the threshold is problematic because as batteries age, the original fixed threshold may no longer be suitable. Judging based on the initial threshold will exacerbate battery damage or waste energy storage capacity.

[0075] In a preferred but non-limiting embodiment of the present invention, the improved overcharge protection algorithm in step 2 includes:

[0076] The overcharge detection threshold is dynamically adjusted based on the battery status to avoid the problem of insufficient adaptability of fixed thresholds.

[0077] Computational Dynamics SOC Overcharge threshold The calculation formula is as follows: ,in As the basis for setting SOC Overcharge threshold, It can be set to 0.8. The set charging temperature correction factor (reduced when the battery temperature is higher than the optimal value) SOC (threshold) The value range can be set to 0.5~1 (unit: % / ℃). For the MAX function, The set optimal operating temperature for the battery. It can be set to 25℃;

[0078] Calculate the dynamic battery voltage overcharge threshold The calculation formula is as follows:

[0079] ,in The set base battery voltage overcharge threshold, It can be set to 4.2V. The set charging power correction factor (reduces the voltage threshold at high power). The value range can be set to 0.05~0.1. The rated charging power of the energy storage battery pack. For the MIN function, For charging power, That is The product value given that its value is greater than zero. For the MAX function, The set voltage temperature correction factor (reduces the voltage threshold when the temperature is above 40℃). The value range can be set to 0.005~0.01 (unit: 1 / ℃).

[0080] dynamic SOC Overcharge threshold and dynamic battery voltage overcharge threshold The calculation formulas are all designed based on the electrochemical characteristics of energy storage battery packs, rural power grid operation scenarios, and core overcharge protection requirements, in dynamic... SOC Overcharge threshold In the calculation formula, battery health status SOHDirectly reflects the difference between the current maximum usable capacity and the initial capacity of the energy storage battery pack. SOH The degradation is essentially an irreversible decrease in capacity caused by the loss of electrode active materials and electrolyte aging in energy storage battery packs. When SOH When the battery is 100% (brand new), the correction factor is 0.9 + 0.1. 100% = 1.0 Make full use of the battery's rated capacity; when SOH When the battery reaches 60% (aged battery), the correction factor is 0.9 + 0.1. 60% = 0.96 Lowering the overcharge threshold can prevent artificially high overcharge rates caused by capacity reduction in aging batteries. SOC The corresponding risk of overcharging is that the actual capacity of an aging battery decreases, if it is still charged at the initial level. SOC Exceeding the battery's charging capacity can lead to electrolyte decomposition and thermal runaway. This correction item... This aligns with the physical law that capacity decay during the aging process of energy storage battery packs leads to a decrease in overcharge tolerance. Temperature correction term in the calculation formula During the charging process of the energy storage battery pack, the temperature exceeds the optimal operating temperature. At 25°C, the electrode reaction rate of energy storage battery packs accelerates, side reactions (such as lithium dendrite growth and electrolyte oxidation) intensify, and the risk of overcharging increases exponentially. (In the formula...) Ensure that corrections are triggered only when the temperature is above the optimal value, by Reduce dynamic SOC Overcharge threshold, i.e., At 45℃, it is 20℃ higher than 25℃. =0.8% / ℃, then dynamic SOC The overcharge threshold decreased by 0.8%. 20% = 16%, reducing the charging capacity at high temperatures to avoid excessive side reactions. This is consistent with the thermodynamics of batteries: for every 10°C increase in temperature, the rate of side reactions increases by about 2 to 3 times, and the risk needs to be balanced by lowering the upper limit of charging.

[0081] Dynamic battery voltage overcharge threshold In the calculation formula, during high-power charging, the internal polarization effect of the energy storage battery pack intensifies (ohmic polarization, concentration polarization), causing a momentary surge in the battery pack's voltage. This voltage includes both the polarization voltage and the actual open-circuit voltage. If judged based on a fixed voltage threshold, the momentary high voltage caused by polarization is easily misjudged as overcharging. In the formula... Ensure the power correction factor is between 0 and 1: when When, adjust according to the actual power ratio; when At that time, adjust according to the full rated power. (Through...) Lower the dynamic battery voltage overcharge threshold, for example At that time, the dynamic battery voltage overcharge threshold decreases. (like =0.08, then reduce by 8%), to offset the influence of polarization voltage and avoid misjudgment; at the same time, the energy storage battery pack heats up more severely during high-power charging, and reducing the dynamic battery voltage overcharge threshold can also indirectly reduce the charging amount and alleviate heat accumulation, which is consistent with the physical logic that high power leads to high polarization, which in turn leads to a high risk of overcharge. When the temperature is higher than 40℃, the battery internal resistance of the energy storage battery pack decreases but the side reactions intensify. The battery voltage at the same charging amount will be slightly higher than at room temperature, but the overcharge tolerance is significantly reduced. At this time, it is necessary to strengthen protection while avoiding misjudgment. In the formula Ensure that corrections are triggered only in the high-temperature range (T>40℃), by Reduce the temperature of the energy storage battery pack: For example, at T=50℃, which is 10℃ higher than 40℃, if =0.008 1 / ℃, then the dynamic battery voltage overcharge threshold decreases by 0.008. 10 = 8%, which avoids misjudgment caused by polarization voltage at high temperatures, and reduces the risk of overcharging by lowering the upper limit of voltage, which is in line with the dual laws of voltage characteristic deviation and overcharge tolerance of energy storage battery packs under high temperature environment.

[0082] Rural power grids have dispersed loads and unstable renewable energy (wind power) output, leading to frequent fluctuations in charging power (such as a sudden surge in charging power when wind power increases). The power correction term for the dynamic battery voltage overcharge threshold can adapt to power changes in real time, avoiding false triggering of protection due to sudden voltage spikes caused by power changes. This ensures stable operation of the energy storage system under grid fluctuation scenarios. For example, if a sudden voltage change in the rural power grid causes the charging power to rise from 50kW (rated power 100kW) to 120kW, the formula min(1,120 / 100)=1 corrects the dynamic battery voltage overcharge threshold based on the full power, avoiding misjudgment and strengthening protection under high power by lowering the threshold, thus adapting to the dynamic operating conditions of the rural power grid.

[0083] In rural areas, where centralized temperature control facilities are lacking, battery operating temperatures are significantly affected by the seasons (reaching above 45°C in summer and dropping as low as -10°C in winter). The temperature correction terms in the two formulas are designed for scenarios above the optimal temperature and above 40°C, respectively, precisely adapting to the outdoor temperature characteristics of rural areas: during hot summer months, the temperature is adjusted by reducing... SOC With a dynamic battery voltage overcharge threshold, the charging amount is reduced to mitigate the risk of thermal runaway. In spring and autumn at normal temperatures, the threshold is close to the baseline value, making full use of the energy storage capacity and balancing energy storage efficiency and safety protection. This solves the problem of insufficient or excessive protection under extreme temperatures when the fixed threshold is applied.

[0084] Rural energy storage systems have low maintenance frequency and are cost-sensitive, requiring algorithms with full lifecycle adaptability that eliminates the need for manual adjustments. (The two formulas...)SOH The correction items and cycle degradation correlation logic can automatically adapt to batteries from brand new ( SOH =100%) to aging ( SOH The state change (e.g., after the energy storage battery pack has been in operation for 3 years) does not require manual adjustment of the threshold by maintenance personnel. SOH Reduced to 80%, dynamic SOC The overcharge threshold automatically decreases from 80% (baseline value) to 76.8%, and the dynamic voltage overcharge threshold is indirectly related to... SOH The system automatically adjusts to mitigate the impact of polarization (which is more pronounced when aging batteries are charged at high power), reducing maintenance costs and making it suitable for rural maintenance scenarios.

[0085] The two dynamic threshold formulas are physically aligned with the evolution of battery overcharge risk, and are suitable for the characteristics of rural power grids, such as large fluctuations, drastic temperature changes, and sensitivity to operation and maintenance costs. In terms of protection logic, they achieve a balance between precise protection and energy storage efficiency, and the parameter values ​​are engineering-feasible. Compared with fixed threshold algorithms, their core rationality lies in dynamically adapting to changes in multiple factors, solving the overcharge protection pain point of rural energy storage systems under complex operating conditions, and providing reliable algorithmic support for extending battery life and ensuring the safe and stable operation of the system.

[0086] In a preferred but non-limiting embodiment of the present invention, in step 2, the improved over-discharge protection algorithm includes:

[0087] Calculate the dynamic SOC over-discharge threshold The calculation formula is as follows:

[0088] ,in The set base SOC over-discharge threshold, The value can be set to 20%. The set discharge temperature correction factor (increased when the temperature is below the optimal value) SOC (threshold) The value range can be set to 0.3~0.8 (unit: % / ℃);

[0089] Calculate the dynamic battery voltage over-discharge threshold The calculation formula is as follows: ,in The set base battery voltage over-discharge threshold, It can be set to 3.0V. The set discharge power correction factor (increases the voltage threshold at high power). The value range can be set to 0.03~0.08. For discharge power, That is The product value under the condition that its value is less than zero. This refers to the rated discharge power of the energy storage battery pack. The set discharge voltage temperature correction factor (increases the dynamic battery voltage over-discharge threshold when the temperature is below -10℃). The value range can be set to 0.003~0.006 (unit: 1 / ℃).

[0090] dynamic SOC Over-discharge threshold and dynamic battery voltage over-discharge threshold The calculation formulas are all based on the over-discharge damage mechanism of energy storage battery packs, the characteristics of rural power grid operation scenarios, and the core objectives of over-discharge protection design, in dynamic... SOC Over-discharge threshold In the calculation formula, the battery health status ( SOH The core issue of battery degradation is the reduction in active electrode materials and the increase in internal resistance of the energy storage battery pack. This leads to a decrease in the actual usable capacity of the battery and a reduction in its over-discharge tolerance. Aged batteries (low-voltage) exhibit this degradation. SOH If still fixed as a brand new battery SOC Excessive discharge beyond the threshold will lead to deep discharge due to insufficient actual capacity, causing damage to the electrode structure and a permanent increase in internal resistance of the energy storage battery pack. (The formula contains 0.9 + 0.1.) SOH constitute SOH Correction factor: when SOH When the battery is 100% (brand new), the correction factor is 1.0. Make full use of the battery's rated available capacity; when SOH When the battery percentage is 60% (aged battery), the correction factor is 0.96. By appropriately increasing dynamic SOC The over-discharge threshold reduces the depth of discharge in aging batteries, preventing damage from deep over-discharge. This correction is in line with... SOH The lower the value, the lower the tolerance to over-discharge, thus requiring an increase in dynamic range. SOC The battery degradation pattern under over-discharge threshold. During the discharge process of energy storage battery packs, the temperature is below the optimal operating temperature. At 25℃, the electrolyte ion migration rate decreases, the internal resistance increases significantly, and the voltage drop under the same discharge current intensifies, making voltage collapse more likely. This appears to be a result of... SOC The over-discharge threshold was not reached, but the actual battery voltage had already dropped to a dangerous level, causing over-discharge damage. (In the formula...) Ensure that the correction is triggered only in low-temperature scenarios (T < 25°C), through Improve dynamics SOC Over-discharge threshold: For example, at T=-10℃, which is 35℃ lower than 25℃, if =0.5% / ℃, then SOC The threshold was increased by 0.5%. 35 = 17.5% (from the base threshold of 20% to the dynamic threshold of 37.5%), stopping discharge early to avoid latent over-discharge caused by voltage collapse at low temperatures. This is consistent with the low-temperature electrochemical characteristics of energy storage battery packs: for every 10°C decrease in temperature, the internal resistance of the energy storage battery pack increases by 30%~50%, and the risk of over-discharge increases exponentially.

[0091] Dynamic battery voltage over-discharge threshold In the calculation formula, during high-power discharge, the internal polarization effect (ohmic polarization, concentration polarization) of the energy storage battery pack is significantly enhanced, leading to a momentary drop in battery voltage. This voltage includes the polarization voltage drop and the actual open-circuit voltage. If judged according to a fixed voltage threshold, the momentary low voltage caused by polarization is easily misjudged as over-discharge, or actual over-discharge may occur because the polarization voltage is not considered. In the formula... Normalize the discharge power to the 0~1 range: when When, adjust according to the actual power ratio; when At that time, adjust according to the full rated power. (Through...) Increase the voltage over-discharge threshold: for example At that time, the dynamic battery voltage over-discharge threshold improve (like =0.06, then increase by 6%), to offset the effect of polarization voltage drop, avoid shutdown due to instantaneous low voltage misjudgment during high-power discharge, and ensure that the actual open-circuit voltage is not lower than the safe level. This conforms to the physical law that the higher the discharge power, the stronger the polarization, and the higher the dynamic voltage over-discharge threshold needs to be. However, when the temperature is below -10℃, the electrolyte of the energy storage battery pack is close to the freezing point, ion migration is extremely difficult, internal resistance increases sharply, and the voltage drop under the same discharge conditions is much higher than at room temperature, and the over-discharge damage is irreversible (such as the large-scale growth of lithium dendrites and the shedding of electrode active material). In the formula Ensure that corrections are triggered only in extremely low temperature scenarios (T < -10℃), through Increase the dynamic voltage over-discharge threshold: For example, at T=-20℃, 10℃ lower than -10℃, if If the temperature is 0.0051℃, then the voltage threshold increases by 0.005℃. 10 = 5% (from the base threshold of 3.0V to the dynamic threshold of 3.15V), stop discharging in advance to avoid irreversible over-discharge damage at extremely low temperatures. This is in line with the rule that the voltage drop increases dramatically due to extremely low temperatures, thus making the over-discharge damage irreversible and requiring a significant increase in the voltage over-discharge threshold.

[0092] These two dynamic over-discharge threshold formulas are physically aligned with the evolution of battery over-discharge damage. They are suitable for the characteristics of rural power grids, such as large load fluctuations, drastic temperature changes, and sensitivity to operation and maintenance costs. Logically, they achieve a balance between over-discharge safety protection and energy storage discharge efficiency, and the parameter values ​​are engineering-feasible. Compared to fixed threshold algorithms, their core rationality lies in dynamically adapting to changes in multiple factors, solving the over-discharge protection deficiencies of rural energy storage systems under complex operating conditions. This provides reliable algorithmic support for extending battery life and stabilizing system power supply, demonstrating significant engineering value and application prospects.

[0093] The technical advantages of the main station control unit in analyzing battery operating parameters through improved overcharge protection and over-discharge protection algorithms are as follows:

[0094] Reduce false positive rate and improve energy storage efficiency: Adapt charging and discharging power, temperature, and other parameters through dynamic thresholds. SOH By varying parameters, overprotection caused by a single static threshold can be avoided. Experiments have verified that the number of false shutdowns during high-power charging is reduced by 90%, the over-discharge false alarm rate is reduced by 85% in low-temperature environments (-10℃), and the usable capacity of the energy storage battery is increased by 10%~15%.

[0095] Precise battery protection and extended lifespan: The threshold is adjusted based on the battery's health status to avoid overcharging and over-discharging damage to aging batteries caused by fixed thresholds; the graded protection mechanism reduces the impact of instantaneous fluctuations on the battery. Tests have shown that the battery cycle life is extended by more than 40% compared to the original algorithm, and the capacity decay rate is reduced by 50%.

[0096] Improve system stability and adapt to rural power grid characteristics: The delayed judgment logic filters out interference factors such as power grid fluctuations and measurement errors, reducing the system failure rate by 70%; the dynamic threshold is adapted to the characteristics of rural power grid load fluctuations and unstable new energy power generation, ensuring that the protection algorithm can still operate stably under complex working conditions and reducing the impact on the power grid supply and demand balance.

[0097] Enhanced algorithm robustness, adapting to the entire lifecycle: The algorithm covers batteries from brand new ( SOH =100%) to aging ( SOH The algorithm has a full lifecycle of 60% (=60%), eliminating the need for manual threshold adjustment and reducing operation and maintenance costs; the temperature and power correction mechanisms are adapted to different seasons and load scenarios in rural areas, improving the versatility and reliability of the algorithm.

[0098] In a preferred but non-limiting embodiment of the present invention, the method for risk assessment in step 2 includes:

[0099] when SOC ≥ or ≥ At that time, it was determined that there was a risk of overcharging; whenSOC ≤ or ≤ At that time, it was determined that there was a risk of over-releasing.

[0100] Step 3: The main station control unit generates control commands based on the risk assessment results;

[0101] In a preferred but non-limiting embodiment of the present invention, step 3 specifically includes:

[0102] If there is no risk of overcharging or over-discharging, the main station control unit calculates the target charging and discharging power using a dynamic charging and discharging power adjustment algorithm. The calculation formula is:

[0103] ;

[0104] in, The set remaining power adjustment coefficient ( The value range can be set to 0.5-2.0kW / %, which is used to adjust the charging and discharging power according to the difference between the current remaining battery power and the target remaining battery power. The load balance adjustment coefficient ( The value range can be set to 0.3-1.0 (dimensionless), which is used to adjust the charging and discharging power according to the difference between the power supplied by the power grid and the load power to achieve load balance in rural power grids; The set target remaining power ( The value range can be set to 30%-70%.

[0105] If the battery temperature exceeds the optimal operating range (the optimal operating range can be set to T < T_low or T > T_high, where T_low is -10℃ and T_high is 45℃), the target charge / discharge power will be affected. Temperature correction is performed to achieve the final target charge / discharge power. :

[0106] ;

[0107] in, The set temperature correction factor ( The value range can be set to 0.01-0.051 / ℃ to avoid excessive charging and discharging power affecting battery safety when the temperature is abnormal;

[0108] If the battery temperature does not exceed the optimal operating range This is the final target charging and discharging power, from which a power adjustment command containing the final target charging and discharging power is generated;

[0109] If there is a risk of overcharging, a stop charging command is generated; if there is a risk of over-discharging, a stop discharging command is generated. The stop charging command, stop discharging command, and power adjustment command are all control commands.

[0110] By using two independent components, the dual objectives of optimizing the state of the energy storage battery pack itself and balancing the supply and demand of the power grid are achieved in a coordinated manner, which is in line with the dual attributes of distributed energy storage services themselves and serving rural power grids.

[0111] Remaining battery power adjustment item Focusing on the safety of energy storage battery packs, when SOC When the value is below the target value, charging is driven; when the value is above the target value, discharging is driven. This avoids the energy storage battery pack being in a fully charged / fully discharged state for a long time, thus extending its lifespan.

[0112] Load balancing adjustment item Focusing on the stability of rural power grids, the system absorbs surplus electricity when rural power grids have a power supply surplus and releases electricity when power supply is insufficient, thereby smoothing out load fluctuations in rural power grids.

[0113] The two sub-items are algebraically superimposed without logical conflict. When demand is consistent, power is superimposed (e.g., energy storage battery packs are depleted while rural power grids have surplus power, accelerating charging). When demand conflicts, a balance is struck through coefficient weights (e.g., rural power grids prioritize power supply, which can increase power output). (Weight), which aligns with the essential nature of energy storage system operation.

[0114] For each deviation from the target SOC The power adjustment range at 1% covers a range from stable adjustment (0.5kW / %) to rapid replenishment (2.0kW / %), adapting to different load scenarios in rural areas (for example, a higher value is used when rapid response is needed during busy farming seasons; and a lower value is used when stable adjustment is needed during off-seasons).

[0115] The weighting of the impact of the power grid supply and demand difference is determined by taking a higher value when the power grid in remote rural areas has weak carrying capacity (prioritizing power grid stability) and a lower value when the power grid is close to towns (prioritizing battery protection), which is in line with the differentiated needs of rural power grids.

[0116] Avoiding the lifespan-sensitive ranges of full charge (>80%) and full discharge (<20%) of energy storage battery packs, and dynamically adapting to historical and predicted loads, ensuring sufficient capacity is reserved to cope with sudden demand, and conforming to the electrochemical characteristics of energy storage battery packs.

[0117] The charge / discharge efficiency, cycle life, and safety risks of energy storage battery packs are all strongly correlated with temperature: at low temperatures (T < -10℃), the electrolyte ion migration rate decreases, internal resistance increases by 30%-50%, and high-power charge / discharge easily leads to voltage collapse and lithium dendrite growth, causing irreversible damage; at high temperatures (T > 45℃), the electrode reaction rate accelerates, the risk of side reactions (electrolyte decomposition, thermal runaway) increases dramatically, and high-power charge / discharge exacerbates heat accumulation, exceeding the battery safety threshold. The temperature correction formula, through power attenuation logic, reduces the battery load at abnormal temperatures from the source, conforming to the physical law that the further the temperature deviates from the optimal value, the lower the battery tolerance, requiring lower charge / discharge power. The accuracy of the correction logic is based on the absolute value term. : Ensures that corrections are triggered whenever the temperature is above or below the optimal value, covering all abnormal temperature scenarios and avoiding protection vulnerabilities caused by one-way corrections;

[0118] coefficient For every 1°C deviation of the temperature from the optimal value, the charging and discharging power decreases by 1%-5%. The range of values ​​conforms to the temperature sensitivity of lithium batteries (power decreases by 20%-100% when the temperature deviates from 20°C). This avoids energy storage efficiency loss due to over-correction and effectively mitigates safety risks.

[0119] Step 4: The main station control unit controls the charging and discharging actions according to the control commands.

[0120] In a preferred but non-limiting embodiment of the present invention, step 4 specifically includes:

[0121] The master station control unit transmits control commands to the energy storage converter. If the control command is a power adjustment command, the energy storage converter adjusts its charging and discharging power to the final target power specified in the command. If the control command is a stop charging command, the energy storage converter stops charging; if the control command is a stop discharging command, the energy storage converter stops discharging. The rural power grid is also known as the rural distribution network.

[0122] like Figure 2 As shown, the present invention provides an energy storage system for rural power grids, comprising:

[0123] The wind power energy storage pole unit, the main station control unit, and the battery protection unit work together to achieve safe and efficient storage and release of electrical energy; both the wind power energy storage pole unit and the battery protection unit are communicatively connected to the main station control unit.

[0124] Wind power energy storage pole unit: As the core execution component of the energy storage system for rural power grids, it includes a wind turbine and a battery energy storage module installed on the pole body, as mentioned in the technical solution with patent announcement number "CN221978615U". The wind turbine includes a wind sensor. The wind turbine starts generating electricity when its wind sensor detects a level 3 light wind. The electricity is transmitted to the rural power distribution network through the overhead line of the distribution network. Part of the electricity is input on the AC side of the energy storage converter, converted into DC electricity and stored in the energy storage battery pack.

[0125] In a preferred but non-limiting embodiment of the present invention, the battery energy storage module is the core carrier of electrical energy storage, including an energy storage battery pack, an energy storage converter, a battery management unit, and a three-phase meter.

[0126] The battery protection unit is used to collect the operating parameters of the energy storage module's battery pack in real time. These parameters include the battery voltage (which is the total voltage of the energy storage battery pack), battery current (which is the charging and discharging current of the energy storage battery pack), battery temperature (which is the temperature of the battery cells in the energy storage battery pack), and remaining battery capacity (which represents the remaining capacity of the energy storage battery pack). SOC The battery protection unit obtains the parameter data of the operating parameters, which provides accurate input for the subsequent control algorithm and is the basis for realizing overcharge and over-discharge protection.

[0127] In a preferred but non-limiting embodiment of the present invention, the battery protection unit includes a voltage sensor, a current sensor, a temperature sensor and a SOC sensor connected to the energy storage battery pack. The current sensor is connected in series between the energy storage battery pack and the energy storage converter. The voltage sensor, current sensor, temperature sensor and SOC sensor are used to collect the battery voltage, battery current, battery temperature and remaining battery power of the energy storage battery pack, respectively.

[0128] Master Station Control Unit: As the control core of the energy storage system for rural power grids, it receives operating parameters of the energy storage battery pack from the battery protection unit and load data of the rural power grid collected and transmitted from the three-phase metering meters. Based on preset improved overcharge protection algorithms, improved over-discharge protection algorithms, and dynamic charge / discharge power adjustment algorithms, it generates corresponding control commands. The master station control unit can dynamically adjust the charging and discharging strategy according to the dynamic changes in the rural power grid load and the real-time operating status of the battery, ensuring precise matching between the charging and discharging process and the battery status and grid demand. The master station control unit can be a server or a computer. The improved overcharge protection algorithm includes:

[0129] Computational Dynamics SOC Overcharge threshold The calculation formula is as follows: ,in The set base SOC overcharge threshold, This is the set charging temperature correction factor. For the MAX function, The set optimal operating temperature for the battery;

[0130] Calculate the dynamic battery voltage overcharge threshold The calculation formula is as follows:

[0131] ,in The set base battery voltage overcharge threshold, The set charging power correction factor. The rated charging power of the energy storage battery pack. For the MIN function, For charging power, That is The product value given that its value is greater than zero. For the MAX function, This is the set voltage-temperature correction factor;

[0132] Improved over-discharge protection algorithms include:

[0133] Computational Dynamics SOC Over-discharge threshold The calculation formula is as follows:

[0134] ,in As the basis for setting SOC Over-discharge threshold, This is the set discharge temperature correction factor. The value range can be set to 0.3~0.8;

[0135] Calculate the dynamic battery voltage over-discharge threshold The calculation formula is as follows: ,in The set base battery voltage over-discharge threshold, The set discharge power correction factor, For discharge power, That is The product value under the condition that its value is less than zero. This refers to the rated discharge power of the energy storage battery pack. Temperature correction factor for the set discharge voltage

[0136] The beneficial effects of the present invention are as follows, compared with the prior art:

[0137] Avoiding overcharging and over-discharging to extend battery life: The battery protection unit monitors battery operating parameters in real time, combining overcharge and over-discharge protection algorithms with dynamic charge / discharge power adjustment algorithms to precisely control the start / stop and power of charging and discharging, effectively preventing damage to the battery from overcharging and over-discharging. Experimental verification shows that using the storage method of this invention can extend the cycle life of energy storage batteries by more than 30%, reduce the battery capacity decay rate by 40%, and significantly reduce battery replacement costs.

[0138] Enhancing system operational safety: Multiple protection mechanisms are implemented, including parameter threshold protection and temperature correction protection, to promptly mitigate safety risks such as thermal runaway and fires caused by overcharging and over-discharging. Furthermore, the use of ultra-high-performance concrete poles and the balanced control of the battery management unit further improve the overall structural and electrical safety of the system, reducing the system failure rate by more than 60%.

[0139] Adapting to the characteristics of rural power grids and optimizing energy utilization: The dynamic charging and discharging power regulation algorithm fully considers the characteristics of rural power grid load dispersion, volatility, and unstable renewable energy generation. It can adjust the charging and discharging strategy in real time according to changes in grid supply and demand and battery status, achieving local consumption of renewable energy and grid load balance. Practical application tests have shown that the renewable energy consumption rate of rural power grids has increased by more than 25%, and the grid load fluctuation has decreased by 30%, effectively alleviating the power supply pressure on rural power grids.

[0140] Stable and reliable operation with low maintenance costs: The system adopts dual-mode communication and high-precision acquisition modules, ensuring stable data transmission and accurate parameter monitoring; the intelligent control of the main station control unit reduces manual intervention, and maintenance personnel can remotely monitor the system's operating status through the data monitoring platform and promptly handle alarm information, reducing maintenance costs by more than 50%, making it suitable for rural power grid maintenance scenarios.

[0141] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent updates can still be made to the specific embodiments of the present invention without departing from the spirit and scope of the present invention, and any modifications or equivalent updates should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for storing electrical energy in rural power grids, characterized in that, include: Step 1: Collect the operating parameters of the energy storage battery pack of the energy storage system for rural power grids and the load power of rural distribution networks and transmit them to the main station control unit; After the energy storage system for rural power grids is activated, the battery protection unit collects data on the energy storage battery pack, including battery voltage, in real time. Battery current Battery temperature and remaining battery power The operating parameters of the three-phase electricity meter are used to collect the load power of the rural power distribution network. The communication module transmits this data to the main station control unit in real time; simultaneously, the main station control unit obtains the power supply of the rural power distribution network. Battery health status of energy storage battery packs ; Step 2: The main station control unit performs risk assessment based on the operating parameters of the energy storage battery pack; the main station control unit analyzes the battery operating parameters using an improved overcharge protection algorithm and an improved over-discharge protection algorithm to perform risk assessment; wherein: The improved overcharge protection algorithm includes: Computational Dynamics SOC Overcharge threshold The calculation formula is as follows: ,in The set base SOC overcharge threshold, This is the set charging temperature correction factor. For the MAX function, The set optimal operating temperature for the battery; Calculate the dynamic battery voltage overcharge threshold The calculation formula is as follows: ,in The set base battery voltage overcharge threshold, The set charging power correction factor. The rated charging power of the energy storage battery pack. For the MIN function, For charging power, That is The product value given that its value is greater than zero. For the MAX function, This is the set voltage-temperature correction factor; The improved over-discharge protection algorithm includes: Computational Dynamics SOC Over-discharge threshold The calculation formula is as follows: ,in As the basis for setting SOC Over-discharge threshold, This is the set discharge temperature correction factor. The value range can be set to 0.3~0.8; Calculate the dynamic battery voltage over-discharge threshold The calculation formula is as follows: ,in The set base battery voltage over-discharge threshold, The set discharge power correction factor, For discharge power, That is The product value under the condition that its value is less than zero. This refers to the rated discharge power of the energy storage battery pack. This is the set temperature correction factor for the discharge voltage; Step 3: The main station control unit generates control commands based on the risk assessment results; including: If there is no risk of overcharging or over-discharging, the main station control unit calculates the target charging and discharging power using a dynamic charging and discharging power adjustment algorithm. The calculation formula is: ； in, The remaining power adjustment coefficient is set; This is the load balancing adjustment coefficient; The set target remaining battery power; If the battery temperature exceeds the optimal operating range, the target charge / discharge power will be affected. Temperature correction is performed to achieve the final target charge / discharge power. : ； in, The set temperature correction factor; If the battery temperature does not exceed the optimal operating range This is the final target charging and discharging power, from which a power adjustment command containing the final target charging and discharging power is generated; If there is a risk of overcharging, a stop charging command is generated; if there is a risk of over-discharging, a stop discharging command is generated. The stop charging command, stop discharging command, and power adjustment command are all control commands. Step 4: The main station control unit controls the charging and discharging actions according to the control commands.

2. The energy storage method for rural power grids according to claim 1, characterized in that, In step 2, the methods for risk assessment include: when SOC ≥ or ≥ At that time, it was determined that there was a risk of overcharging; when SOC ≤ or ≤ At that time, it was determined that there was a risk of over-releasing.

3. The energy storage method for rural power grids according to claim 1, characterized in that, Step 4 specifically includes: The master station control unit transmits control commands to the energy storage converter. If the control command is a power adjustment command, the energy storage converter adjusts the charging and discharging power to the final target charging and discharging power in the power adjustment command. If the control command is a stop charging command, the energy storage converter stops charging. If the control command is a stop discharging command, the energy storage converter stops discharging.

4. An energy storage system employing the energy storage method for rural power grids as described in any one of claims 1-3, characterized in that, include: Wind power energy storage pole unit, main station control unit and battery protection unit; Both the wind power energy storage pole unit and the battery protection unit are communicatively connected to the main station control unit; Wind power energy storage pole units include battery energy storage modules installed on the pole body; The battery protection unit is used to collect the operating parameters of the energy storage battery pack of the battery energy storage module in real time. The operating parameters of the energy storage battery pack include the battery voltage, battery current, battery temperature and remaining battery capacity. The main station control unit receives the operating parameters of the energy storage battery pack transmitted by the battery protection unit and the load data of the rural power grid collected and transmitted by the three-phase metering meter. Based on the preset improved overcharge protection algorithm, improved over-discharge protection algorithm and dynamic charge and discharge power adjustment algorithm, it generates corresponding control commands.

5. The energy storage system for rural power grids according to claim 4, characterized in that, The battery energy storage module includes an energy storage battery pack, an energy storage converter, a battery management unit, and a three-phase meter. The battery protection unit includes voltage sensors, current sensors, temperature sensors, and other sensors connected to the energy storage battery pack. SOC Sensors, including a current sensor connected in series between the energy storage battery pack and the energy storage converter, and voltage, current, and temperature sensors, are also present. SOC The sensors are used to collect data on the battery voltage, battery current, battery temperature, and remaining battery power of the energy storage battery pack.

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