Reactive compensation method and system based on average power factor and real-time power factor

Abstract

The invention discloses a reactive power compensation method and system based on an average power factor and a real-time power factor, and belongs to the technical field of reactive power optimization of an energy storage system. According to the method, the target value of the average power factor and the upper limit value of the average power factor are preset, and the reactive compensation mode is selected according to the actual demand of the energy storage system, so that the energy storage system can actively participate in the regulation of the average power factor according to the power demand of an enterprise, and the blank in the prior art that the energy storage system participates in the regulation of the average power factor is filled; whether reactive power is countercurrent or not is judged through ammeter data, the load rate of the transformer is calculated, the load rate factor is brought into compensation logic, and safe and stable operation of a power grid is guaranteed. According to the method, the problem that the real-time power factor is reduced due to grid connection of the energy storage system is solved, the power utilization cost of an enterprise is reduced by increasing the average power factor, and the dual requirements of stable operation of a power grid and power utilization economy of the enterprise are met.

Description

Technical Field

[0001] The present invention relates to the technical field of reactive power optimization of energy storage systems, and in particular to a reactive power compensation method and system based on average power factor and real-time power factor. Background Art

[0002] As a high-quality, flexible resource, energy storage plays a key role in promoting the integration of new energy and ensuring the safe and stable operation of power systems. It is a crucial support force for achieving energy conservation and carbon reduction. Thanks to supportive industry policies, technological breakthroughs, and growing market demand, the energy storage industry is experiencing robust growth.

[0003] However, with the continued expansion of the energy storage market, the phenomenon of a decrease in the real-time power factor at the grid connection point during the grid connection process of energy storage systems is becoming increasingly serious. This decrease in the real-time power factor can have an adverse impact on the safe and stable operation of the power grid, such as increasing line losses and reducing the power supply efficiency of the grid. In addition, in some regions, the assessment indicators for corporate electricity costs are closely related to the average power factor. Specifically, these regions use the average power factor calculated from the total active power and the total reactive power of the month as the assessment indicator, and use this to calculate corporate electricity costs. When the average power factor is higher than the standard value, the company's electricity costs are reduced, that is, improving the average power factor can reduce the company's electricity expenses; conversely, when the average power factor is lower than the standard value, the company's electricity costs increase, and the company's electricity costs increase.

[0004] At present, the existing technologies for power factor regulation have many defects and shortcomings. On the one hand, for the regulation of average power factor, most technologies do not consider energy storage from the perspective of energy storage, and lack effective means of optimizing by using energy storage systems. On the other hand, the existing methods of optimizing real-time power factor by performing reactive compensation through energy storage systems fail to fully consider the impact of load factors, resulting in poor improvement of real-time power factor in actual engineering applications, which cannot meet the dual needs of stable grid operation and economical electricity consumption of enterprises.

[0005] Therefore, how to combine the optimization of average power factor with real-time power factor to provide a reactive power compensation method that can meet the dual needs of stable operation of the power grid and economic efficiency of enterprise electricity consumption has become a technical problem that needs to be overcome urgently by current technicians in this field. Summary of the Invention

[0006] The purpose of the present invention is to provide a reactive power compensation method and system based on average power factor and real-time power factor, so as to overcome the problem that the existing technology cannot simultaneously meet the dual needs of stable operation of the power grid and economic efficiency of enterprise electricity consumption.

[0007] The present invention solves the above technical problems through the following technical solutions: A reactive power compensation method based on average power factor and real-time power factor comprises the following steps: Step 1: Calculate the current average power factor and real-time power factor of the energy storage system, and preset the average power factor target value, average power factor upper limit value, real-time power factor upper limit value, and real-time power factor target value. Select a reactive power compensation mode based on the actual needs of the energy storage system. The reactive power compensation mode includes an average power factor compliance mode, an average power factor improvement mode, and a real-time power factor optimization mode. Step 2: When the reactive power compensation mode is the average power factor compliance mode, determine whether the current average power factor of the energy storage system has not reached the average power factor target value. If so, execute step 3; if not, maintain the current reactive power of the energy storage system; when the reactive power compensation mode is the average power factor improvement mode, determine whether the current average power factor of the energy storage system has reached the average power factor upper limit. If so, execute step 3; if not, maintain the current reactive power of the energy storage system; when the reactive power compensation mode is the real-time power factor optimization mode, determine whether the current real-time power factor of the energy storage system has reached the real-time power factor upper limit. If so, maintain the current reactive power of the energy storage system. If not, execute step 3; Step 3: Obtain meter data from the energy storage system's grid connection point, and determine whether reactive power is flowing backward based on the meter data. If so, set the energy storage system's current reactive power compensation power to zero; if not, calculate the transformer load factor at the energy storage system's grid connection point. Step 4: Determine whether the transformer load rate exceeds the limit. If the transformer load rate exceeds the limit, set the current reactive compensation power of the energy storage system to zero. If the transformer load rate does not exceed the limit, calculate the actual reactive compensation power of the energy storage system and perform reactive power compensation on the energy storage system based on the actual reactive compensation power.

[0008] A further improvement of the present invention is that when it is determined that the transformer load rate is within the limit, the battery charge state of the energy storage system is collected to determine whether the battery charge state is between 10% and 90% of the power. If the judgment is not, the current reactive compensation power of the energy storage system is set to zero. If the judgment is yes, the actual reactive compensation power of the energy storage system is calculated, and reactive power compensation is performed on the energy storage system based on the actual reactive compensation power.

[0009] A further improvement of the present invention is that: when it is determined that the transformer load rate is within the limit, it is determined whether the energy storage system is in the power-on state. If it is determined not, a power-on instruction is issued; if it is determined yes, it is determined whether the energy storage system has a fault. If the result of the determination is that a fault exists, the current reactive compensation power of the energy storage system is set to zero; if the result of the determination is that there is no fault, the actual reactive compensation power of the energy storage system is calculated, and reactive power compensation is performed on the energy storage system according to the actual reactive compensation power.

[0010] The present invention is further improved in that it further includes step five, specifically: Obtain the rated voltage and current voltage of the energy storage system's grid connection point, and determine whether the current voltage is greater than or equal to 1.1 times the rated voltage. If not, exit the current round of energy storage system reactive power compensation and return to step 1 to enter the next round of energy storage system reactive power compensation. If yes, preset a step size and gradually reduce the actual reactive compensation power according to the step size until the current voltage is less than 1.1 times the rated voltage.

[0011] The present invention is further improved in that: the determination of whether the transformer load rate exceeds the limit is specifically as follows: When the transformer load factor is greater than or equal to 85% of the transformer capacity, the transformer load factor is out of limit; when the transformer load factor is less than 85% of the transformer capacity, the transformer load factor is within the limit; The specific method of judging whether reactive power is reverse-flowing according to the electric meter data is as follows: The electric meter data includes reverse reactive power. When the reverse reactive power is greater than zero, the reactive power is reverse flowing; when the reverse reactive power is equal to zero, the reactive power is not reverse flowing.

[0012] The present invention is further improved in that: the reactive power compensation mode is selected according to the actual needs of the energy storage system in the following manner: When actual demand requires saving enterprise electricity costs, select either the average power factor compliance mode or the average power factor improvement mode. The average power factor improvement mode can save more enterprise electricity costs than the average power factor compliance mode. When actual demand requires improving the real-time power factor of the power grid, select the real-time power factor optimization mode.

[0013] The present invention is further improved in that the average power factor is specifically:

[0014] in, is the average power factor; is the total active electric energy of the month; is the total reactive energy of the month; The real-time power factor is specifically:

[0015] in, is the real-time power factor, is the current active power; is the current reactive power.

[0016] The present invention is further improved in that the transformer load rate of the energy storage system grid connection point is calculated as follows:

[0017] in, is the transformer load factor, is the reactive power of the energy storage system grid connection point, is the active power of the energy storage system grid connection point; is the transformer capacity.

[0018] The present invention is further improved in that the actual reactive compensation power of the energy storage system is calculated as follows:

[0019] in, is the actual reactive compensation power of the energy storage system; min() is the minimum function; The maximum reactive compensation power required by the energy storage system when the transformer reaches the maximum transformer load rate; The reactive compensation power required by the energy storage system when the current real-time power factor of the energy storage system is equal to the real-time power factor target value; The reactive compensation power required by the energy storage system when the current real-time power factor of the energy storage system reaches the upper limit of the real-time power factor; The maximum allowable reactive compensation power of the energy storage system; The maximum reactive compensation power required by the energy storage system when the transformer reaches the maximum transformer load rate Specifically:

[0020] in, is the maximum transformer load factor; The reactive compensation power required by the energy storage system when the current real-time power factor of the energy storage system is equal to the real-time power factor target value Specifically:

[0021] in, is the real-time power factor target value; The reactive compensation power required by the energy storage system when the current real-time power factor of the energy storage system reaches the upper limit of the real-time power factor Specifically:

[0022] in, It is the upper limit value of real-time power factor; Maximum allowable reactive compensation power of the energy storage system Specifically:

[0023] in, is the capacity of the energy storage system; is the active power of the energy storage system.

[0024] The present invention also provides a reactive power compensation system based on average power factor and real-time power factor, comprising: The first module is used to calculate the current average power factor and real-time power factor of the energy storage system, and preset the average power factor target value, average power factor upper limit value, real-time power factor upper limit value and real-time power factor target value, and select the reactive power compensation mode according to the actual needs of the energy storage system. The reactive power compensation mode includes the average power factor compliance mode, the average power factor improvement mode and the real-time power factor optimization mode; The second module is used to determine whether the current average power factor of the energy storage system has not reached the average power factor target value when the reactive compensation mode is the average power factor compliance mode. If the judgment is yes, the third module is executed; if the judgment is no, the current reactive compensation power of the energy storage system is maintained; when the reactive compensation mode is the average power factor improvement mode, it is determined whether the current average power factor of the energy storage system has reached the average power factor upper limit. If the judgment is yes, the third module is executed; if the judgment is no, the current reactive compensation power of the energy storage system is maintained; when the reactive compensation mode is the real-time power factor optimization mode, it is determined whether the current real-time power factor of the energy storage system has reached the real-time power factor upper limit. If the judgment is yes, the current reactive compensation power of the energy storage system is maintained. If the judgment is no, the third module is executed; The third module is used to obtain meter data from the energy storage system's grid connection point and determine whether reactive power is reverse flowing based on the meter data. If so, the current reactive power compensation power of the energy storage system is set to zero; if not, the transformer load rate of the energy storage system's grid connection point is calculated. The fourth module is used to determine whether the transformer load rate exceeds the limit. If the transformer load rate is determined to be exceeded, the current reactive compensation power of the energy storage system is set to zero. If the transformer load rate is determined to be within the limit, the actual reactive compensation power of the energy storage system is calculated and reactive power compensation is performed on the energy storage system based on the actual reactive compensation power.

[0025] Compared with the prior art, the present invention has the following positive effects: The reactive power compensation method based on average power factor and real-time power factor provided by the present invention presets an average power factor target value and an average power factor upper limit value, and selects a reactive compensation mode according to the actual needs of the energy storage system, so that the energy storage system can actively participate in the average power factor regulation according to the enterprise's electricity demand, filling the gap in the existing technology for energy storage systems to participate in average power factor regulation. It also determines whether reactive power is reversely flowing through meter data, calculates the transformer load factor, and incorporates the load factor factor into the compensation logic, ensuring the safe and stable operation of the power grid. This method not only solves the problem of reduced real-time power factor caused by the grid connection of the energy storage system, but also reduces the enterprise's electricity cost by improving the average power factor, achieving the dual needs of meeting the stable operation of the power grid and the economic efficiency of enterprise electricity consumption.

[0026] Furthermore, the reactive power output capability of an energy storage system is closely related to the battery's state of charge. When the battery's state of charge is too low, the energy storage system can output reactive power, but this weakens its ability to meet other power regulation needs (such as peak shaving). When the battery's state of charge is too high, its reactive power absorption capacity is limited, making it difficult to meet the grid's dynamic reactive power needs. This method only performs reactive power compensation within a reasonable state of charge range, ensuring that the energy storage system has sufficient active power reserves and capacity margin while improving the power factor. This ensures the effectiveness and sustainability of reactive power compensation and enhances the energy storage system's support for the grid.

[0027] Furthermore, this method ensures that reactive power compensation has basic operating conditions by judging the startup status; by judging the fault status, once a fault is detected, the reactive compensation power is immediately set to zero, avoiding compensation failure or safety risks caused by faulty operation, and establishing reactive power compensation on the basis of stable system operation, thereby improving the effectiveness and reliability of the compensation strategy.

[0028] Furthermore, this method monitors the relationship between the current voltage and the rated voltage of the grid connection point. When the current voltage reaches or exceeds 1.1 times the rated voltage, it immediately triggers the voltage over-limit protection mechanism and gradually reduces the reactive compensation power according to the preset step size, thereby avoiding the impact of large sudden changes in reactive compensation power on the power grid and ensuring the stability of the power grid voltage, thereby providing users with better quality and more stable power supply and improving the user's electricity experience.

[0029] Furthermore, this method can suspend compensation when the transformer is close to full load, avoid the increase of additional current due to reactive power regulation, prevent the transformer from long-term overload operation, effectively extend the life of the equipment, reduce operation and maintenance costs and power outage risks; at the same time, prevent the problem of local voltage increase caused by reactive power reverse flow, maintain the balanced voltage distribution of the power grid, and avoid the impact of voltage anomalies on equipment safety and power supply quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The drawings in the specification are used to provide further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0031] Figure 1 The present invention is a flowchart of a reactive power compensation method based on average power factor and real-time power factor. DETAILED DESCRIPTION

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0033] In the description of the present invention, it is to be understood that the terms “include” and “comprise” indicate the presence of the described features, wholes, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or collections thereof.

[0034] It should also be understood that the terms used in the present specification are only for the purpose of describing particular embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0035] It should be understood that although the terms "first," "second," and "third" may be used to describe preset ranges in embodiments of the present invention, these preset ranges should not be limited to these terms. These terms are merely used to distinguish one preset range from another. For example, without departing from the scope of embodiments of the present invention, the first preset range may also be referred to as the second preset range, and similarly, the second preset range may also be referred to as the first preset range.

[0036] The word "if," as used herein, may be interpreted as "at the time of" or "when" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrases "if it is determined" or "if (stated condition or event) is detected" may be interpreted as "when it is determined" or "in response to the determination" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)," depending on the context.

[0037] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, which are intended to explain the present invention rather than to limit it.

[0038] See also Figure 1 , a reactive power compensation method based on average power factor and real-time power factor, comprising the following steps: Step 1: Calculate the current average power factor and real-time power factor of the energy storage system, and preset the average power factor target value, average power factor upper limit value, real-time power factor upper limit value, and real-time power factor target value. Select a reactive power compensation mode based on the actual needs of the energy storage system. The reactive power compensation mode includes an average power factor compliance mode, an average power factor improvement mode, and a real-time power factor optimization mode. Step 2: When the reactive power compensation mode is the average power factor compliance mode, determine whether the current average power factor of the energy storage system has not reached the average power factor target value. If so, execute step 3; if not, maintain the current reactive power of the energy storage system; when the reactive power compensation mode is the average power factor improvement mode, determine whether the current average power factor of the energy storage system has reached the average power factor upper limit. If so, execute step 3; if not, maintain the current reactive power of the energy storage system; when the reactive power compensation mode is the real-time power factor optimization mode, determine whether the current real-time power factor of the energy storage system has reached the real-time power factor upper limit. If so, maintain the current reactive power of the energy storage system. If not, execute step 3; Step 3: Obtain meter data from the energy storage system's grid connection point, and determine whether reactive power is flowing backward based on the meter data. If so, set the energy storage system's current reactive power compensation power to zero; if not, calculate the transformer load factor at the energy storage system's grid connection point. Step 4: Determine whether the transformer load rate exceeds the limit. If the transformer load rate exceeds the limit, set the current reactive compensation power of the energy storage system to zero. If the transformer load rate does not exceed the limit, calculate the actual reactive compensation power of the energy storage system and perform reactive power compensation on the energy storage system based on the actual reactive compensation power.

[0039] This method follows the following principles when applied: (1) Prioritize the active power output of the energy storage system, and the reactive power compensation cannot exceed the apparent power; (2) Prioritize reactive power compensation when the energy storage system is discharging, and then perform reactive power compensation when it is stationary and charging; (3) The grid-connected point of the energy storage system, that is, the low-voltage side of the transformer, must prevent excessive reactive compensation, so as to avoid a slowdown in the increase of the average power factor, resulting in the average power factor not meeting the standard; (4) The charging, discharging or reactive power compensation of the energy storage system cannot cause the transformer to overload, thereby increasing the risk of transformer burning; (5) The grid-connected point voltage cannot exceed the limit due to reactive power compensation, and the safe operation of the power grid must be guaranteed.

[0040] This method integrates the control requirements of real-time power factor and average power factor. Using a real-time power factor optimization mode, it responds to real-time power factor fluctuations during grid connection. It then combines average power factor compliance and average power factor improvement modes to optimize enterprise electricity consumption metrics over the long term, resulting in a reactive power compensation method combining "short-term real-time compensation with long-term average optimization." By presetting an average power factor target value and an average power factor upper limit, and selecting a reactive power compensation mode based on the actual needs of the energy storage system, the energy storage system can proactively participate in average power factor control based on enterprise electricity needs (e.g., achieving compliance to avoid increased electricity bills, or improving to reduce electricity costs). This method fills a gap in existing technologies for energy storage's involvement in average power factor control. It also uses meter data to determine whether reactive power is reverse flowing (to prevent reverse reactive power from impacting the grid), calculates the transformer load factor, and incorporates the load factor into the compensation logic, ensuring safe and stable grid operation. This method not only addresses the problem of real-time power factor degradation caused by grid connection, but also reduces enterprise electricity costs by improving the average power factor, thus meeting the dual requirements of grid stability and enterprise electricity economy.

[0041] Specifically, when it is determined that the transformer load rate is within the limit, the battery state of charge of the energy storage system is collected to determine whether the battery charge state is between 10% and 90% of the power. If the judgment is not, the current reactive compensation power of the energy storage system is set to zero. If the judgment is yes, the actual reactive compensation power of the energy storage system is calculated, and reactive power compensation is performed on the energy storage system based on the actual reactive compensation power.

[0042] The reactive power output capability of an energy storage system is closely related to the battery's state of charge (SOC). When the battery's SOC is too low, the energy storage system can output reactive power, but this weakens its ability to meet other power regulation needs (such as peak shaving). When the battery's SOC is too high, its reactive power absorption capacity is limited, making it difficult to meet the grid's dynamic reactive power needs. This method only performs reactive power compensation within a reasonable SOC range, ensuring that the energy storage system maintains sufficient active power reserves and capacity margin while improving the power factor. This ensures the effectiveness and sustainability of reactive power compensation and enhances the energy storage system's support for the grid.

[0043] Specifically, when it is determined that the transformer load rate is within the limit, it is determined whether the energy storage system is in the power-on state. If not, a power-on command is issued; if so, it is determined whether the energy storage system has a fault. If the result is that a fault exists, the current reactive compensation power of the energy storage system is set to zero; if the result is that there is no fault, the actual reactive compensation power of the energy storage system is calculated, and reactive power compensation is performed on the energy storage system based on the actual reactive compensation power.

[0044] This method ensures that reactive power compensation has basic operating conditions by judging the startup status; by judging the fault status, once a fault is detected, the reactive compensation power is immediately set to zero, avoiding compensation failure or safety risks caused by faulty operation, and establishing reactive power compensation on the basis of stable system operation, thereby improving the effectiveness and reliability of the compensation strategy.

[0045] Specifically, it also includes step five, which is: Obtain the rated voltage and current voltage of the energy storage system's grid connection point, and determine whether the current voltage is greater than or equal to 1.1 times the rated voltage. If not, exit the current round of energy storage system reactive power compensation and return to step 1 to enter the next round of energy storage system reactive power compensation. If yes, preset a step size and gradually reduce the actual reactive compensation power according to the step size until the current voltage is less than 1.1 times the rated voltage.

[0046] This method monitors the relationship between the current voltage and the rated voltage of the grid connection point. When the current voltage reaches or exceeds 1.1 times the rated voltage, it immediately triggers the voltage over-limit protection mechanism and gradually reduces the reactive compensation power according to the preset step size, avoiding the impact of large sudden changes in reactive compensation power on the power grid, ensuring the stability of the power grid voltage, thereby providing users with better quality and more stable power supply and improving the user's power consumption experience.

[0047] Specifically, the determination of whether the transformer load rate exceeds the limit is as follows: When the transformer load factor is greater than or equal to 85% of the transformer capacity, the transformer load factor is out of limit; when the transformer load factor is less than 85% of the transformer capacity, the transformer load factor is within the limit; The specific method of judging whether reactive power is reverse-flowing according to the electric meter data is as follows: The electric meter data includes reverse reactive power. When the reverse reactive power is greater than zero, the reactive power is reverse flowing; when the reverse reactive power is equal to zero, the reactive power is not reverse flowing.

[0048] This method can suspend compensation when the transformer is close to full load, avoid the increase of additional current due to reactive power regulation, prevent the transformer from long-term overload operation, effectively extend the life of the equipment, reduce operation and maintenance costs and power outage risks; at the same time, it prevents the problem of local voltage increase caused by reactive power reverse flow, maintains the balanced voltage distribution of the power grid, and avoids the impact of voltage anomalies on equipment safety and power supply quality.

[0049] Specifically, the reactive power compensation mode is selected according to the actual needs of the energy storage system as follows: When actual demand requires saving enterprise electricity costs, select either the average power factor compliance mode or the average power factor improvement mode. The average power factor improvement mode can save more enterprise electricity costs than the average power factor compliance mode. When actual demand requires improving the real-time power factor of the power grid, select the real-time power factor optimization mode.

[0050] Specifically, the average power factor is:

[0051] in, is the average power factor; is the total active electric energy of the month; is the total reactive energy of the month; The real-time power factor is specifically:

[0052] in, is the real-time power factor, is the current active power; is the current reactive power.

[0053] Specifically, the transformer load rate of the energy storage system grid connection point is calculated as follows:

[0054] in, is the transformer load factor, is the reactive power of the energy storage system grid connection point, is the active power of the energy storage system grid connection point; is the transformer capacity.

[0055] Specifically, the actual reactive compensation power of the energy storage system is calculated as follows:

[0056] in, is the actual reactive compensation power of the energy storage system; min() is the minimum function; The maximum reactive compensation power required by the energy storage system when the transformer reaches the maximum transformer load rate; The reactive compensation power required by the energy storage system when the current real-time power factor of the energy storage system is equal to the real-time power factor target value; The reactive compensation power required by the energy storage system when the current real-time power factor of the energy storage system reaches the upper limit of the real-time power factor; The maximum allowable reactive compensation power of the energy storage system; The maximum reactive compensation power required by the energy storage system when the transformer reaches the maximum transformer load rate Specifically:

[0057] in, is the maximum transformer load factor; The reactive compensation power required by the energy storage system when the current real-time power factor of the energy storage system is equal to the real-time power factor target value Specifically:

[0058] in, is the real-time power factor target value; Real-time power factor target value Specifically:

[0059] The reactive compensation power required by the energy storage system when the current real-time power factor of the energy storage system reaches the upper limit of the real-time power factor Specifically:

[0060] in, It is the upper limit value of real-time power factor; Maximum allowable reactive compensation power of the energy storage system Specifically:

[0061] in, is the capacity of the energy storage system; is the active power of the energy storage system.

[0062] Based on the same inventive concept, the present invention also provides a reactive power compensation system based on average power factor and real-time power factor, comprising: The first module is used to calculate the current average power factor and real-time power factor of the energy storage system, and preset the average power factor target value, average power factor upper limit value, real-time power factor upper limit value and real-time power factor target value, and select the reactive power compensation mode according to the actual needs of the energy storage system. The reactive power compensation mode includes the average power factor compliance mode, the average power factor improvement mode and the real-time power factor optimization mode; The second module is used to determine whether the current average power factor of the energy storage system has not reached the average power factor target value when the reactive compensation mode is the average power factor compliance mode. If the judgment is yes, the third module is executed; if the judgment is no, the current reactive compensation power of the energy storage system is maintained; when the reactive compensation mode is the average power factor improvement mode, it is determined whether the current average power factor of the energy storage system has reached the average power factor upper limit. If the judgment is yes, the third module is executed; if the judgment is no, the current reactive compensation power of the energy storage system is maintained; when the reactive compensation mode is the real-time power factor optimization mode, it is determined whether the current real-time power factor of the energy storage system has reached the real-time power factor upper limit. If the judgment is yes, the current reactive compensation power of the energy storage system is maintained. If the judgment is no, the third module is executed; The third module is used to obtain meter data from the energy storage system's grid connection point and determine whether reactive power is reverse flowing based on the meter data. If so, the current reactive power compensation power of the energy storage system is set to zero; if not, the transformer load rate of the energy storage system's grid connection point is calculated. The fourth module is used to determine whether the transformer load rate exceeds the limit. If the transformer load rate is determined to be exceeded, the current reactive compensation power of the energy storage system is set to zero. If the transformer load rate is determined to be within the limit, the actual reactive compensation power of the energy storage system is calculated and reactive power compensation is performed on the energy storage system based on the actual reactive compensation power.

[0063] This system can compensate for reactive power by combining the average power factor with the real-time power factor, thereby improving the real-time power factor at the energy storage system's grid connection point, bringing it close to 1 and enhancing energy efficiency. Furthermore, this system can mitigate line voltage drops and line losses caused by reactive power flow, ensuring safe and stable system operation. Furthermore, this system can save businesses electricity costs by improving the average power factor. In a specific embodiment of the present invention, the average power factor, with a standard value of 0.90, was increased to 0.95 using this method, reducing the company's monthly electricity costs by 0.75%, which is of great significance to the company's economic development.

[0064] Finally, it should be noted that the embodiments listed above are merely one or more specific manifestations of the technical solution of the present invention. Their purpose is to clearly illustrate the concept, principles, and application of the present invention through specific examples, and is in no way intended to limit the scope of protection of the present invention to these specific embodiments. In fact, the true value of this invention lies in its technical ideas and innovations, not in its form of expression or implementation.

[0065] For ordinary technicians in the relevant technical field, after thoroughly reading and understanding the technical solutions of the present invention, they are fully capable of making various forms of changes, modifications or equivalent replacements to the specific implementation methods of the invention based on their own professional knowledge and skills. These changes may include but are not limited to: adjusting the value range of technical parameters, optimizing algorithm processes to improve efficiency, replacing some technical components to achieve better compatibility or reduce costs, etc. As long as these modified technical solutions still substantially maintain the technical features claimed for protection by the original invention, that is, they can still achieve the core functions and effects of the present invention, then these changes should be deemed to fall within the scope of protection of the pending claims of the present invention.

[0066] Furthermore, with the continuous advancement and development of technology, new technical means and methods continue to emerge, providing ample room for further improvement and perfection of the present invention. Therefore, the scope of protection of the present invention should also include reasonably foreseeable improvements and extensions based on existing technologies. As long as these improvements and extensions do not deviate from the basic principles and core concepts of the present invention, they should be considered equivalent to the present invention and equally protected by patent rights.

Claims

1. A reactive power compensation method based on average power factor and real-time power factor, characterized in that: The following steps are involved: Step 1: Calculate the current average power factor and real-time power factor of the energy storage system, and preset the average power factor target value, average power factor upper limit value, real-time power factor upper limit value, and real-time power factor target value. Select a reactive power compensation mode based on the actual needs of the energy storage system. The reactive power compensation mode includes an average power factor compliance mode, an average power factor improvement mode, and a real-time power factor optimization mode. Step 2: When the reactive power compensation mode is the average power factor compliance mode, determine whether the current average power factor of the energy storage system has not reached the average power factor target value. If so, execute step 3; if not, maintain the current reactive power of the energy storage system; when the reactive power compensation mode is the average power factor improvement mode, determine whether the current average power factor of the energy storage system has reached the average power factor upper limit. If so, execute step 3; if not, maintain the current reactive power of the energy storage system; when the reactive power compensation mode is the real-time power factor optimization mode, determine whether the current real-time power factor of the energy storage system has reached the real-time power factor upper limit. If so, maintain the current reactive power of the energy storage system. If not, execute step 3; Step 3: Obtain meter data from the energy storage system's grid connection point, and determine whether reactive power is flowing backward based on the meter data. If so, set the energy storage system's current reactive power compensation power to zero; if not, calculate the transformer load factor at the energy storage system's grid connection point. Step 4: Determine whether the transformer load rate exceeds the limit. If the transformer load rate exceeds the limit, set the current reactive compensation power of the energy storage system to zero. If the transformer load rate does not exceed the limit, calculate the actual reactive compensation power of the energy storage system and perform reactive power compensation on the energy storage system based on the actual reactive compensation power.

2. The reactive power compensation method based on average power factor and real-time power factor according to claim 1, characterized in that: When it is determined that the transformer load rate is within the limit, the battery state of charge of the energy storage system is collected to determine whether the battery charge state is between 10% and 90% of the power. If not, the current reactive compensation power of the energy storage system is set to zero. If so, the actual reactive compensation power of the energy storage system is calculated, and reactive power compensation is performed on the energy storage system based on the actual reactive compensation power.

3. The reactive power compensation method based on average power factor and real-time power factor according to claim 1, characterized in that: When it is determined that the transformer load rate is within the limit, it is determined whether the energy storage system is in the power-on state. If not, a power-on command is issued; If the answer is yes, determine whether the energy storage system has a fault. If the result of the determination is yes, set the current reactive compensation power of the energy storage system to zero. If the judgment result is that there is no fault, the actual reactive compensation power of the energy storage system is calculated, and reactive power compensation is performed on the energy storage system according to the actual reactive compensation power.

4. The reactive power compensation method based on average power factor and real-time power factor according to claim 1, characterized in that: It also includes step five, specifically: Obtain the rated voltage and current voltage of the energy storage system's grid connection point, and determine whether the current voltage is greater than or equal to 1.1 times the rated voltage. If not, exit the current round of energy storage system reactive power compensation and return to step 1 to enter the next round of energy storage system reactive power compensation. If the answer is yes, a preset step size is set, and the actual reactive compensation power is gradually reduced according to the step size until the current voltage is less than 1.1 times the rated voltage.

5. The reactive power compensation method based on average power factor and real-time power factor according to claim 1, characterized in that: The specific method of determining whether the transformer load rate exceeds the limit is as follows: When the transformer load factor is greater than or equal to 85% of the transformer capacity, the transformer load factor is out of limit; when the transformer load factor is less than 85% of the transformer capacity, the transformer load factor is within the limit; The specific method of judging whether reactive power is reverse-flowing according to the electric meter data is as follows: The meter data includes reverse reactive power. When the reverse reactive power is greater than zero, the reactive power is reversely flowing; when the reverse reactive power is equal to zero, the reactive power is not reversely flowing.

6. The reactive power compensation method based on average power factor and real-time power factor according to claim 1, characterized in that: The reactive power compensation mode selected according to the actual needs of the energy storage system is specifically: When actual demand requires saving enterprise electricity costs, select either the average power factor compliance mode or the average power factor improvement mode. The average power factor improvement mode can save more enterprise electricity costs than the average power factor compliance mode. When actual demand requires improving the real-time power factor of the power grid, select the real-time power factor optimization mode.

7. The reactive power compensation method based on average power factor and real-time power factor according to claim 1, characterized in that: The average power factor is specifically: in, is the average power factor; is the total active electric energy of the month; is the total reactive energy of the month; The real-time power factor is specifically: in, is the real-time power factor, is the current active power; is the current reactive power.

8. The reactive power compensation method based on average power factor and real-time power factor according to claim 7, characterized in that: The transformer load rate of the energy storage system grid connection point is calculated as follows: in, is the transformer load factor, is the reactive power of the energy storage system grid connection point, is the active power of the energy storage system grid connection point; is the transformer capacity.

9. The reactive power compensation method based on average power factor and real-time power factor according to claim 8, characterized in that: The actual reactive compensation power of the energy storage system is calculated as follows: in, is the actual reactive compensation power of the energy storage system; min() is the minimum function; The maximum reactive compensation power required by the energy storage system when the transformer reaches the maximum transformer load rate; The reactive compensation power required by the energy storage system when the current real-time power factor of the energy storage system is equal to the real-time power factor target value; The reactive compensation power required by the energy storage system when the current real-time power factor of the energy storage system reaches the upper limit of the real-time power factor; The maximum allowable reactive compensation power of the energy storage system; The maximum reactive compensation power required by the energy storage system when the transformer reaches the maximum transformer load rate Specifically: in, is the maximum transformer load factor; The reactive compensation power required by the energy storage system when the current real-time power factor of the energy storage system is equal to the real-time power factor target value Specifically: in, is the real-time power factor target value; The reactive compensation power required by the energy storage system when the current real-time power factor of the energy storage system reaches the upper limit of the real-time power factor Specifically: in, It is the upper limit value of real-time power factor; Maximum allowable reactive compensation power of the energy storage system Specifically: in, is the capacity of the energy storage system; is the active power of the energy storage system.

10. A reactive power compensation system based on average power factor and real-time power factor, characterized in that: include: The first module is used to calculate the current average power factor and real-time power factor of the energy storage system, and preset the average power factor target value, average power factor upper limit value, real-time power factor upper limit value and real-time power factor target value, and select the reactive power compensation mode according to the actual needs of the energy storage system. The reactive power compensation mode includes the average power factor compliance mode, the average power factor improvement mode and the real-time power factor optimization mode; The second module is used to determine whether the current average power factor of the energy storage system has not reached the average power factor target value when the reactive compensation mode is the average power factor compliance mode. If the judgment is yes, the third module is executed; if the judgment is no, the current reactive compensation power of the energy storage system is maintained; when the reactive compensation mode is the average power factor improvement mode, it is determined whether the current average power factor of the energy storage system has reached the average power factor upper limit. If the judgment is yes, the third module is executed; if the judgment is no, the current reactive compensation power of the energy storage system is maintained; when the reactive compensation mode is the real-time power factor optimization mode, it is determined whether the current real-time power factor of the energy storage system has reached the real-time power factor upper limit. If the judgment is yes, the current reactive compensation power of the energy storage system is maintained. If the judgment is no, the third module is executed; The third module is used to obtain meter data from the energy storage system's grid connection point and determine whether reactive power is flowing backward based on the meter data. If so, the current reactive power compensation power of the energy storage system is set to zero; if not, the transformer load rate of the energy storage system's grid connection point is calculated. The fourth module is used to determine whether the transformer load rate exceeds the limit. If the transformer load rate is determined to be exceeded, the current reactive compensation power of the energy storage system is set to zero. If the transformer load rate is determined to be within the limit, the actual reactive compensation power of the energy storage system is calculated and reactive power compensation is performed on the energy storage system based on the actual reactive compensation power.

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