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

Abstract

This invention discloses a reactive power compensation method and system based on average power factor and real-time power factor, belonging to the field of reactive power optimization technology for energy storage systems. This method presets a target value and an upper limit value for the average power factor, and selects a reactive power compensation mode according to the actual needs of the energy storage system. This enables the energy storage system to actively participate in average power factor regulation based on the enterprise's electricity demand, filling the gap in existing technologies for energy storage systems participating in average power factor regulation. By using meter data to determine whether reactive power is flowing backward and calculating the transformer load rate, the load rate factor is incorporated into the compensation logic, ensuring the safe and stable operation of the power grid. This method not only solves the problem of real-time power factor reduction caused by grid connection of energy storage systems, but also reduces enterprise electricity costs by improving the average power factor, achieving the dual requirements of stable grid operation and economical enterprise electricity consumption.

Description

Technical Field

[0001] This invention relates to the field of reactive power optimization technology for energy storage systems, specifically to a reactive power compensation method and system based on average power factor and real-time power factor. Background Technology

[0002] Energy storage, as a high-quality and flexible regulatory resource, plays a crucial role in promoting the consumption of new energy sources and ensuring the safe and stable operation of the power system, serving as an important support for achieving energy conservation and carbon reduction. Benefiting from supportive industry policies, breakthroughs in technological innovation, and growing market demand, the energy storage industry is showing a robust and vigorous development trend.

[0003] However, with the continued expansion of the energy storage market, the phenomenon of decreasing 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 real-time power factor can adversely affect the safe and stable operation of the power grid, such as increasing line losses and reducing power supply efficiency. Furthermore, in some regions, the performance indicators for enterprise electricity costs are closely related to the average power factor. Specifically, these regions use the average power factor calculated from the total active and reactive power of the month as a performance indicator, and calculate enterprise electricity costs accordingly. When the average power factor is higher than the standard value, enterprise electricity costs decrease; that is, improving the average power factor can reduce electricity expenses for enterprises. Conversely, when the average power factor is lower than the standard value, enterprise electricity costs increase, and enterprise electricity expenses rise.

[0004] Currently, existing technologies for power factor regulation have many defects and shortcomings. On the one hand, most technologies do not consider energy storage when regulating the average power factor, and lack effective means to optimize it using energy storage systems. On the other hand, existing methods for optimizing real-time power factor through reactive power compensation using energy storage systems fail to fully consider the impact of load factor, resulting in poor real-time power factor improvement in practical engineering applications, which cannot meet the dual needs of stable grid operation and economic efficiency of enterprise electricity consumption.

[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 grid operation and economic efficiency of enterprise electricity consumption has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] The purpose of this 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 power grid operation and economic efficiency of enterprise electricity consumption.

[0007] The present invention solves the above-mentioned technical problems through the following technical solution:

[0008] A reactive power compensation method based on average power factor and real-time power factor includes the following steps:

[0009] Step 1: Calculate the current average power factor and real-time power factor of the energy storage system, and preset the target value of average power factor, the upper limit value of average power factor, the upper limit value of real-time power factor, and the target value of real-time power factor. 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 target mode, the average power factor improvement mode, and the real-time power factor optimization mode.

[0010] Step 2: When the reactive power compensation mode is the average power factor target achievement mode, determine whether the current average power factor of the energy storage system has not reached the average power factor target value. If yes, proceed to Step 3; if no, maintain the current reactive power compensation 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 not reached the upper limit of the average power factor. If yes, proceed to Step 3; if no, maintain the current reactive power compensation 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 upper limit of the real-time power factor. If yes, maintain the current reactive power compensation power of the energy storage system; if no, proceed to Step 3.

[0011] Step 3: Obtain the electricity meter data at the grid connection point of the energy storage system. Determine whether the reactive power is flowing in reverse based on the electricity meter data. If it is, set the current reactive power compensation power of the energy storage system to zero. If it is not, calculate the transformer load rate at the grid connection point of the energy storage system.

[0012] Step 4: Determine if the transformer load rate exceeds the limit. If the transformer load rate exceeds the limit, set the current reactive power compensation power of the energy storage system to zero. If the transformer load rate does not exceed the limit, calculate the actual reactive power compensation power of the energy storage system and perform reactive power compensation on the energy storage system based on the actual reactive power compensation power.

[0013] A further improvement of this invention is that: when it is determined that the transformer load rate is not exceeded, the battery charge state of the energy storage system is collected, and it is determined whether the battery charge state is 10% to 90% of the power. If it is not determined, the current reactive power compensation power of the energy storage system is set to zero. If it is determined, the actual reactive power 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 power compensation power.

[0014] A further improvement of this invention is as follows: when it is determined that the transformer load rate is not exceeded, it is determined whether the energy storage system is in the powered-on state. If the determination is no, a power-on command is issued; if the determination is yes, it is determined whether the energy storage system has a fault. If the determination result is that a fault exists, the current reactive power compensation power of the energy storage system is set to zero; if the determination result is that no fault exists, the actual reactive power 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 power compensation power.

[0015] A further improvement of the present invention is that it also includes step five, specifically:

[0016] Obtain the rated voltage and current voltage of the energy storage system's grid connection point. Determine if the current voltage is greater than or equal to 1.1 times the rated voltage. If not, exit the current round of reactive power compensation for the energy storage system and return to step one to enter the next round of reactive power compensation for the energy storage system. If yes, preset the step size and gradually reduce the actual reactive power compensation power according to the step size until the current voltage is less than 1.1 times the rated voltage.

[0017] A further improvement of this invention is that the determination of whether the transformer load rate exceeds the limit specifically involves:

[0018] When the transformer load rate is greater than or equal to 85% of the transformer capacity, the transformer load rate is considered to be exceeding the limit; when the transformer load rate is less than 85% of the transformer capacity, the transformer load rate is considered to be within the limit.

[0019] The specific steps for determining whether reactive power is flowing in reverse based on meter data are as follows:

[0020] The meter data includes reverse reactive power. When the reverse reactive power is greater than zero, the reactive power flows in reverse; when the reverse reactive power is equal to zero, the reactive power does not flow in reverse.

[0021] A further improvement of this invention is that: the selection of reactive power compensation mode according to the actual needs of the energy storage system specifically refers to:

[0022] When actual needs require saving on enterprise electricity costs, choose either the average power factor target mode or the average power factor improvement mode. The average power factor improvement mode can save more on enterprise electricity costs than the average power factor target mode.

[0023] When actual needs require improving the real-time power factor of the power grid, select the real-time power factor optimization mode.

[0024] A further improvement of this invention is that the average power factor is specifically:

[0025]

[0026] in, The average power factor; This represents the total reactive power for the month. This represents the total active power for the month.

[0027] The real-time power factor is specifically...

[0028]

[0029] in, For real-time power factor, This represents the current reactive power. This represents the current active power.

[0030] A further improvement of this invention is that the transformer load factor at the grid connection point of the energy storage system is specifically calculated as follows:

[0031]

[0032] in, For transformer load rate, The reactive power at the grid connection point of the energy storage system. The active power at the grid connection point of the energy storage system; This refers to the transformer capacity.

[0033] A further improvement of this invention is that the actual reactive power compensation power of the calculated energy storage system is specifically:

[0034]

[0035] in, The actual reactive power compensation of the energy storage system; min() is the minimum value function; This is the maximum reactive power compensation required by the energy storage system when the transformer reaches its maximum transformer load rate. This is the reactive power compensation required by the energy storage system when its current real-time power factor equals the target real-time power factor value. This is the reactive power compensation required by the energy storage system when its current real-time power factor reaches the upper limit of the real-time power factor. This represents the maximum permissible reactive power compensation for the energy storage system.

[0036] The maximum reactive power required by the energy storage system when the transformer reaches its maximum transformer load rate Specifically:

[0037]

[0038] in, This represents the maximum transformer load rate.

[0039] The reactive power compensation required by the energy storage system when its current real-time power factor equals the target real-time power factor value. Specifically:

[0040]

[0041] in, The target value for real-time power factor;

[0042] The reactive power compensation required by the energy storage system when its current real-time power factor reaches the upper limit of the real-time power factor value. Specifically:

[0043]

[0044] in, This is the upper limit of the real-time power factor.

[0045] Maximum permissible reactive power compensation of energy storage system Specifically:

[0046]

[0047] in, The capacity of the energy storage system; This refers to the active power of the energy storage system.

[0048] The present invention also provides a reactive power compensation system based on average power factor and real-time power factor, comprising:

[0049] 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 target value of average power factor, the upper limit value of average power factor, the upper limit value of real-time power factor and the target value of real-time power factor. It selects 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 target mode, the average power factor improvement mode and the real-time power factor optimization mode.

[0050] The second module is used to determine whether the current average power factor of the energy storage system has not reached the target value when the reactive power compensation mode is the average power factor compliance mode. If the determination is yes, the third module is executed; if the determination is no, the current reactive power compensation power of the energy storage system is maintained. When the reactive power compensation mode is the average power factor improvement mode, it determines whether the current average power factor of the energy storage system has not reached the upper limit value of the average power factor. If the determination is yes, the third module is executed; if the determination is no, the current reactive power compensation power of the energy storage system is maintained. When the reactive power compensation mode is the real-time power factor optimization mode, it determines whether the current real-time power factor of the energy storage system has reached the upper limit value of the real-time power factor. If the determination is yes, the current reactive power compensation power of the energy storage system is maintained; if the determination is no, the third module is executed.

[0051] The third module is used to obtain the electricity meter data at the grid connection point of the energy storage system, and determine whether the reactive power is reversed based on the electricity meter data. If it is determined to be reversed, the current reactive power compensation power of the energy storage system is set to zero; if it is determined to be reversed, the transformer load rate at the grid connection point of the energy storage system is calculated.

[0052] The fourth module is used to determine whether the transformer load rate exceeds the limit. If the transformer load rate exceeds the limit, the current reactive power compensation power of the energy storage system is set to zero. If the transformer load rate does not exceed the limit, the actual reactive power 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 power compensation power.

[0053] Compared with the prior art, the positive and progressive effects of the present invention are as follows:

[0054] This invention provides a reactive power compensation method based on average power factor and real-time power factor. By presetting a target value and an upper limit value for the average power factor, and selecting a reactive power compensation mode according to the actual needs of the energy storage system, the method enables the energy storage system to actively participate in average power factor regulation based on the enterprise's electricity demand, filling the gap in existing technologies regarding the participation of energy storage systems in average power factor regulation. Furthermore, by using meter data to determine whether reactive power is flowing backward and calculating the transformer load rate, the method incorporates the load rate factor into the compensation logic, ensuring the safe and stable operation of the power grid. This method not only solves the problem of real-time power factor reduction caused by grid connection of energy storage systems, but also reduces enterprise electricity costs by improving the average power factor, thus achieving the dual requirements of stable grid operation and economical enterprise electricity consumption.

[0055] Furthermore, the reactive power output capability of an energy storage system is closely related to the battery's state of charge (SOC). When the SOC is too low, although the energy storage system can output reactive power, it weakens its ability to meet other power regulation demands (such as peak shaving); when the SOC is too high, its reactive power absorption capacity is limited, making it difficult to meet the dynamic reactive power demand of the power grid. This method only performs reactive power compensation within a reasonable SOC range, ensuring that the energy storage system has sufficient active power reserves and capacity margins while improving the power factor, thus guaranteeing the effectiveness and sustainability of reactive power compensation and enhancing the energy storage system's support role for the power grid.

[0056] Furthermore, this method ensures that reactive power compensation has the basic operating conditions by judging the power-on status; and by judging the fault status, it immediately sets the reactive power compensation power to zero once a fault is detected, avoiding compensation failure or safety risks caused by operating with faults, so that reactive power compensation is based on the stable operation of the system, thereby improving the effectiveness and reliability of the compensation strategy.

[0057] Furthermore, this method monitors the relationship between the current voltage and the rated voltage at 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, gradually reducing the reactive power compensation power according to the preset step size. This avoids the impact of large-scale changes in reactive power compensation power on the power grid, ensuring the stability of the power grid voltage, thereby providing users with a higher quality and more stable power supply and improving the user's electricity experience.

[0058] Furthermore, this method can pause compensation when the transformer is close to full load, avoiding additional current increase due to reactive power regulation, preventing long-term overload operation of the transformer, effectively extending equipment life, reducing operation and maintenance costs and power outage risks; at the same time, it prevents local voltage rise caused by reactive power reverse flow, maintains the balance of grid voltage distribution, and avoids affecting equipment safety and power supply quality due to voltage anomalies. Attached Figure Description

[0059] The accompanying drawings are provided to further understand the invention and constitute a part of this invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0060] Figure 1 This is a flowchart illustrating a reactive power compensation method based on average power factor and real-time power factor according to the present invention. Detailed Implementation

[0061] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0062] In the description of this invention, it should be understood that the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0063] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this 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.

[0064] It should be understood that although terms such as first, second, third, etc., may be used in the embodiments of the present invention to describe the preset range, these preset ranges should not be limited to these terms. These terms are only used to distinguish the preset ranges from one another. For example, without departing from the scope of the 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.

[0065] Depending on the context, the word "if" as used here can be interpreted as "when," "when," "in response to determination," or "in response to detection." Similarly, depending on the context, the phrase "if determination" or "if detection (of the stated condition or event)" can be interpreted as "when determination," "in response to determination," "when detection (of the stated condition or event)," or "in response to detection (of the stated condition or event)."

[0066] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. This is an explanation of the present invention and not a limitation thereof.

[0067] See Figure 1 A reactive power compensation method based on average power factor and real-time power factor includes the following steps:

[0068] Step 1: Calculate the current average power factor and real-time power factor of the energy storage system, and preset the target value of average power factor, the upper limit value of average power factor, the upper limit value of real-time power factor, and the target value of real-time power factor. 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 target mode, the average power factor improvement mode, and the real-time power factor optimization mode.

[0069] Step 2: When the reactive power compensation mode is the average power factor target achievement mode, determine whether the current average power factor of the energy storage system has not reached the average power factor target value. If yes, proceed to Step 3; if no, maintain the current reactive power compensation 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 not reached the upper limit of the average power factor. If yes, proceed to Step 3; if no, maintain the current reactive power compensation 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 upper limit of the real-time power factor. If yes, maintain the current reactive power compensation power of the energy storage system; if no, proceed to Step 3.

[0070] Step 3: Obtain the electricity meter data at the grid connection point of the energy storage system. Determine whether the reactive power is flowing in reverse based on the electricity meter data. If it is, set the current reactive power compensation power of the energy storage system to zero. If it is not, calculate the transformer load rate at the grid connection point of the energy storage system.

[0071] Step 4: Determine if the transformer load rate exceeds the limit. If the transformer load rate exceeds the limit, set the current reactive power compensation power of the energy storage system to zero. If the transformer load rate does not exceed the limit, calculate the actual reactive power compensation power of the energy storage system and perform reactive power compensation on the energy storage system based on the actual reactive power compensation power.

[0072] The following principles should be followed when applying this method: (1) Priority should be given to ensuring the active power output of the energy storage system, and the reactive power compensation should not exceed the apparent power; (2) Reactive power compensation should be carried out first when the energy storage system is discharging, and then in turn during rest and charging; (3) The grid connection point of the energy storage system, i.e. the low-voltage side of the transformer, should be prevented from excessive reactive power compensation, so as to avoid the slow increase of the average power factor and the failure of the average power factor to meet the standard; (4) The charging, discharging or reactive power compensation of the energy storage system should not cause the transformer to overload, thereby increasing the risk of transformer burnout; (5) The voltage at the grid connection point should not exceed the limit due to reactive power compensation, and the safe operation of the power grid should be ensured.

[0073] This method integrates the control requirements of real-time power factor and average power factor. It responds in real-time to power factor fluctuations during grid connection through a real-time power factor optimization mode, and combines an average power factor target achievement mode and an average power factor improvement mode to optimize enterprise electricity consumption performance indicators in the long term, forming a reactive power compensation method of "short-term real-time compensation + long-term average optimization". By presetting the average power factor target value and the average power factor upper limit value, and selecting the reactive power compensation mode according to the actual needs of the energy storage system, the energy storage system can actively participate in average power factor regulation based on the enterprise's electricity consumption needs (such as meeting targets to avoid increased electricity bills, or improving to reduce electricity costs), filling the gap in existing technology regarding energy storage participation in average power factor regulation. It uses meter data to determine whether reactive power is flowing backward (avoiding reverse reactive power impacting the grid) and calculates the transformer load rate, incorporating the load rate factor into the compensation logic to ensure the safe and stable operation of the power grid. This method not only solves the problem of real-time power factor reduction caused by energy storage system grid connection, but also reduces enterprise electricity costs by improving the average power factor, achieving the dual requirements of meeting the stable operation of the power grid and the economic efficiency of enterprise electricity consumption.

[0074] Specifically, when it is determined that the transformer load rate is not exceeded, the battery charge state of the energy storage system is collected to determine whether the battery charge state is 10% to 90% of the power. If the determination is no, the current reactive power compensation power of the energy storage system is set to zero. If the determination is yes, the actual reactive power 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 power compensation power.

[0075] The reactive power output capability of an energy storage system is closely related to the battery's state of charge (SOC). When the SOC is too low, although the energy storage system can output reactive power, it weakens its ability to meet other power regulation needs (such as peak shaving); when the SOC is too high, its reactive power absorption capacity is limited, making it difficult to meet the dynamic reactive power demand of the power grid. This method only performs reactive power compensation within a reasonable SOC range, ensuring that the energy storage system has sufficient active power reserves and capacity margins while improving the power factor, thus guaranteeing the effectiveness and sustainability of reactive power compensation and enhancing the energy storage system's support role for the power grid.

[0076] Specifically, when it is determined that the transformer load rate is not exceeded, it is determined whether the energy storage system is in the powered-on state. If the determination is no, a power-on command is issued; if the determination is yes, it is determined whether there is a fault in the energy storage system. If the determination result is that there is a fault, the current reactive power compensation power of the energy storage system is set to zero; if the determination result is that there is no fault, the actual reactive power 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 power compensation power.

[0077] This method ensures that reactive power compensation has the basic operating conditions by judging the power-on status; and by judging the fault status, it immediately sets the reactive power compensation power to zero once a fault is detected, avoiding compensation failure or safety risks caused by operating with faults. This ensures that reactive power compensation is based on the stable operation of the system, thereby improving the effectiveness and reliability of the compensation strategy.

[0078] Specifically, it also includes step five, which is as follows:

[0079] Obtain the rated voltage and current voltage of the energy storage system's grid connection point. Determine if the current voltage is greater than or equal to 1.1 times the rated voltage. If not, exit the current round of reactive power compensation for the energy storage system and return to step one to enter the next round of reactive power compensation for the energy storage system. If yes, preset the step size and gradually reduce the actual reactive power compensation power according to the step size until the current voltage is less than 1.1 times the rated voltage.

[0080] This method monitors the relationship between the current voltage and the rated voltage at 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, gradually reducing the reactive power compensation power according to the preset step size. This avoids the impact of large changes in reactive power compensation power on the power grid, ensures the stability of the power grid voltage, and thus provides users with a better and more stable power supply, improving the user's electricity experience.

[0081] Specifically, determining whether the transformer load rate exceeds the limit involves:

[0082] When the transformer load rate is greater than or equal to 85% of the transformer capacity, the transformer load rate is considered to be exceeding the limit; when the transformer load rate is less than 85% of the transformer capacity, the transformer load rate is considered to be within the limit.

[0083] The specific steps for determining whether reactive power is flowing in reverse based on meter data are as follows:

[0084] The meter data includes reverse reactive power. When the reverse reactive power is greater than zero, the reactive power flows in reverse; when the reverse reactive power is equal to zero, the reactive power does not flow in reverse.

[0085] This method can pause compensation when the transformer is close to full load, avoiding the increase of extra current due to reactive power regulation, preventing the transformer from operating under overload for a long time, effectively extending equipment life, reducing operation and maintenance costs and power outage risks; at the same time, it prevents the problem of local voltage rise caused by reactive power reverse flow, maintains the balance of grid voltage distribution, and avoids the impact of voltage abnormalities on equipment safety and power supply quality.

[0086] Specifically, selecting the reactive power compensation mode based on the actual needs of the energy storage system means as follows:

[0087] When actual needs require saving on enterprise electricity costs, choose either the average power factor target mode or the average power factor improvement mode. The average power factor improvement mode can save more on enterprise electricity costs than the average power factor target mode.

[0088] When actual needs require improving the real-time power factor of the power grid, select the real-time power factor optimization mode.

[0089] Specifically, the average power factor is as follows:

[0090]

[0091] in, The average power factor; This represents the total reactive power for the month. This represents the total active power for the month.

[0092] The real-time power factor is specifically...

[0093]

[0094] in, For real-time power factor, This represents the current reactive power. This represents the current active power.

[0095] Specifically, the transformer load factor at the grid connection point of the energy storage system is calculated as follows:

[0096]

[0097] in, For transformer load rate, The reactive power at the grid connection point of the energy storage system. The active power at the grid connection point of the energy storage system; This refers to the transformer capacity.

[0098] Specifically, the actual reactive power compensation of the calculated energy storage system is as follows:

[0099]

[0100] in, The actual reactive power compensation of the energy storage system; min() is the minimum value function; This is the maximum reactive power compensation required by the energy storage system when the transformer reaches its maximum transformer load rate. This is the reactive power compensation required by the energy storage system when its current real-time power factor equals the target real-time power factor value. This is the reactive power compensation required by the energy storage system when its current real-time power factor reaches the upper limit of the real-time power factor. This represents the maximum permissible reactive power compensation for the energy storage system.

[0101] The maximum reactive power required by the energy storage system when the transformer reaches its maximum transformer load rate Specifically:

[0102]

[0103] in, This represents the maximum transformer load rate.

[0104] The reactive power compensation required by the energy storage system when its current real-time power factor equals the target real-time power factor value. Specifically:

[0105]

[0106] in, The target value for real-time power factor;

[0107] Real-time power factor target value Specifically:

[0108]

[0109] The reactive power compensation required by the energy storage system when its current real-time power factor reaches the upper limit of the real-time power factor value. Specifically:

[0110]

[0111] in, This is the upper limit of the real-time power factor.

[0112] Maximum permissible reactive power compensation of energy storage system Specifically:

[0113]

[0114] in, The capacity of the energy storage system; This refers to the active power of the energy storage system.

[0115] 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:

[0116] 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 target value of average power factor, the upper limit value of average power factor, the upper limit value of real-time power factor and the target value of real-time power factor. It selects 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 target mode, the average power factor improvement mode and the real-time power factor optimization mode.

[0117] The second module is used to determine whether the current average power factor of the energy storage system has not reached the target value when the reactive power compensation mode is the average power factor compliance mode. If the determination is yes, the third module is executed; if the determination is no, the current reactive power compensation power of the energy storage system is maintained. When the reactive power compensation mode is the average power factor improvement mode, it determines whether the current average power factor of the energy storage system has not reached the upper limit value of the average power factor. If the determination is yes, the third module is executed; if the determination is no, the current reactive power compensation power of the energy storage system is maintained. When the reactive power compensation mode is the real-time power factor optimization mode, it determines whether the current real-time power factor of the energy storage system has reached the upper limit value of the real-time power factor. If the determination is yes, the current reactive power compensation power of the energy storage system is maintained; if the determination is no, the third module is executed.

[0118] The third module is used to obtain the electricity meter data at the grid connection point of the energy storage system, and determine whether the reactive power is reversed based on the electricity meter data. If it is determined to be reversed, the current reactive power compensation power of the energy storage system is set to zero; if it is determined to be reversed, the transformer load rate at the grid connection point of the energy storage system is calculated.

[0119] The fourth module is used to determine whether the transformer load rate exceeds the limit. If the transformer load rate exceeds the limit, the current reactive power compensation power of the energy storage system is set to zero. If the transformer load rate does not exceed the limit, the actual reactive power 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 power compensation power.

[0120] This system can compensate for reactive power by combining the average power factor and the real-time power factor, thereby improving the real-time power factor at the grid connection point of the energy storage system, bringing it close to 1 and enhancing energy utilization efficiency. Furthermore, this system can mitigate line voltage drops and line losses caused by reactive power flow, ensuring the safe and stable operation of the system. Simultaneously, this system can save on enterprise electricity costs by improving the average power factor. In a specific embodiment of this invention, by using this method to increase the average power factor from a standard value of 0.90 to 0.95, the enterprise's monthly electricity costs can be reduced by 0.75%, which is of significant importance to the enterprise's economic development.

[0121] Finally, it should be noted that the embodiments listed above are merely one or more specific manifestations of the technical solution of this invention. Their purpose is to clearly illustrate the concept, principle, and application of this invention through specific examples, and is by no means intended to limit the scope of protection of this invention to these specific embodiments. In fact, the true value of this invention lies in its proposed technical ideas and innovations, rather than its manifestations or implementation methods.

[0122] For those skilled in the art, after thoroughly reading and understanding the technical solution of this invention, they are fully capable of making various changes, modifications, or equivalent substitutions to the specific implementation of the invention based on their own professional knowledge and skills. These changes may include, but are not limited to: adjusting the range of technical parameters, optimizing the algorithm flow to improve efficiency, and replacing some technical components to achieve better compatibility or reduce costs. As long as these modified technical solutions substantially retain the technical features claimed by the original invention, that is, they can still achieve the core functions and effects of this invention, then these changes should be considered to fall within the scope of protection of the pending claims of this invention.

[0123] Furthermore, with the continuous progress and development of technology, new technical means and methods are constantly emerging, which provides ample space for further improvement and perfection of this invention. Therefore, the scope of protection of this invention should also include reasonable and foresightful improvements and extensions based on existing technology. As long as these improvements and extensions do not depart from the basic principles and core concepts of this invention, they should be considered equivalents of this invention and are 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, Includes the following steps: Step 1: Calculate the current average power factor and real-time power factor of the energy storage system, and preset the target value of average power factor, the upper limit value of average power factor, the upper limit value of real-time power factor, and the target value of real-time power factor. 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 target mode, the average power factor improvement mode, and the real-time power factor optimization mode. Step 2: When the reactive power compensation mode is the average power factor target achievement mode, determine whether the current average power factor of the energy storage system has not reached the average power factor target value. If yes, proceed to Step 3; if no, maintain the current reactive power compensation 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 not reached the upper limit of the average power factor. If yes, proceed to Step 3; if no, maintain the current reactive power compensation 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 upper limit of the real-time power factor. If yes, maintain the current reactive power compensation power of the energy storage system; if no, proceed to Step 3. Step 3: Obtain the electricity meter data at the grid connection point of the energy storage system. Determine whether the reactive power is flowing in reverse based on the electricity meter data. If it is, set the current reactive power compensation power of the energy storage system to zero. If it is not, calculate the transformer load rate at the grid connection point of the energy storage system. Step 4: Determine if the transformer load rate exceeds the limit. If the transformer load rate exceeds the limit, set the current reactive power compensation power of the energy storage system to zero. If the transformer load rate does not exceed the limit, calculate the actual reactive power compensation power of the energy storage system and perform reactive power compensation on the energy storage system based on the actual reactive power 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 not exceeded, the battery state of charge of the energy storage system is collected to determine whether the battery charge state is 10%~90% of the capacity. If the determination is no, the current reactive power compensation power of the energy storage system is set to zero. If the determination is yes, the actual reactive power 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 power 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 not exceeded, it is determined whether the energy storage system is in the powered-on state. If the determination is not, a power-on command is issued. If the judgment is yes, then determine whether there is a fault in the energy storage system. If the judgment result is that there is a fault, then set the current reactive power compensation power of the energy storage system to zero. If the judgment result is that there is no fault, the actual reactive power 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 power 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, which is as follows: Obtain the rated voltage and current voltage of the energy storage system grid connection point, determine whether the current voltage is greater than or equal to 1.1 times the rated voltage, if not, exit the current round of reactive power compensation for the energy storage system, and return to step one to enter the next round of reactive power compensation for the energy storage system. If the determination is yes, then a preset step size is used, and the actual reactive power 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 steps for determining whether the transformer load rate exceeds the limit are as follows: When the transformer load rate is greater than or equal to 85% of the transformer capacity, the transformer load rate is considered to be exceeding the limit; when the transformer load rate is less than 85% of the transformer capacity, the transformer load rate is considered to be within the limit. The specific steps for determining whether reactive power is flowing in reverse based on meter data are as follows: The meter data includes reverse reactive power. When the reverse reactive power is greater than zero, the reactive power flows in reverse; when the reverse reactive power is equal to zero, the reactive power does not flow in reverse.

6. The reactive power compensation method based on average power factor and real-time power factor according to claim 1, characterized in that, The specific steps for selecting the reactive power compensation mode based on the actual needs of the energy storage system are as follows: When actual needs require saving on enterprise electricity costs, choose either the average power factor target mode or the average power factor improvement mode. The average power factor improvement mode can save more on enterprise electricity costs than the average power factor target mode. When actual needs require 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, The average power factor; This represents the total reactive power for the month. This represents the total active power for the month. The real-time power factor is specifically... in, For real-time power factor, This represents the current reactive power. This represents the current active 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 at the grid connection point of the energy storage system is specifically calculated as follows: in, For transformer load rate, The reactive power at the grid connection point of the energy storage system. The active power at the grid connection point of the energy storage system; This refers to the transformer capacity.

9. A reactive power compensation method based on average power factor and real-time power factor according to claim 8, characterized in that, The actual reactive power compensation power of the calculated energy storage system is specifically as follows: in, The actual reactive power compensation of the energy storage system; min() is the minimum value function; This is the maximum reactive power compensation required by the energy storage system when the transformer reaches its maximum transformer load rate. This is the reactive power compensation required by the energy storage system when its current real-time power factor equals the target real-time power factor value. This is the reactive power compensation required by the energy storage system when its current real-time power factor reaches the upper limit of the real-time power factor. This represents the maximum permissible reactive power compensation for the energy storage system. The maximum reactive power required by the energy storage system when the transformer reaches its maximum transformer load rate Specifically: in, This represents the maximum transformer load rate. The reactive power compensation required by the energy storage system when its current real-time power factor equals the target real-time power factor value. Specifically: in, The target value for real-time power factor; The reactive power compensation required by the energy storage system when its current real-time power factor reaches the upper limit of the real-time power factor value. Specifically: in, This is the upper limit of the real-time power factor. Maximum permissible reactive power compensation of energy storage system Specifically: in, The capacity of the energy storage system; This refers to 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 target value of average power factor, the upper limit value of average power factor, the upper limit value of real-time power factor and the target value of real-time power factor. It selects 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 target 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 target value when the reactive power compensation mode is the average power factor compliance mode. If the determination is yes, the third module is executed; if the determination is no, the current reactive power compensation power of the energy storage system is maintained. When the reactive power compensation mode is the average power factor improvement mode, it determines whether the current average power factor of the energy storage system has not reached the upper limit value of the average power factor. If the determination is yes, the third module is executed; if the determination is no, the current reactive power compensation power of the energy storage system is maintained. When the reactive power compensation mode is the real-time power factor optimization mode, it determines whether the current real-time power factor of the energy storage system has reached the upper limit value of the real-time power factor. If the determination is yes, the current reactive power compensation power of the energy storage system is maintained; if the determination is no, the third module is executed. The third module is used to obtain the electricity meter data at the grid connection point of the energy storage system, and determine whether the reactive power is reversed based on the electricity meter data. If it is determined to be reversed, the current reactive power compensation power of the energy storage system is set to zero; if it is determined to be reversed, the transformer load rate at the grid connection point of the energy storage system is calculated. The fourth module is used to determine whether the transformer load rate exceeds the limit. If the transformer load rate exceeds the limit, the current reactive power compensation power of the energy storage system is set to zero. If the transformer load rate does not exceed the limit, the actual reactive power 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 power compensation power.

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