Intelligent network connection reactive power electric energy management system

Abstract

The invention provides an intelligent network connection reactive power energy management system, which belongs to the technical field of power system energy conservation and comprises an original low-voltage power supply system in a power grid, and I-type reactive power difference compensation equipment, II-type reactive power difference compensation equipment and III-type reactive power difference compensation equipment which are connected with the original low-voltage power supply system, the difference compensation results of the three reactive difference compensation devices are transmitted to the intelligent network connection technology platform through the remote transmission terminal; the I-type reactive compensation equipment is used for low-load compensation in a system transformer and reactive compensation of excitation and copper loss of the transformer; the II-type reactive compensation equipment is used for high-load reactive compensation in the system transformer; and the III-type reactive power difference compensation equipment is connected with the single electric equipment of which the load reactive power is greater than a specific value, and is used for reactive power in-situ difference compensation of the single electric equipment. Layered precise energy compensation is realized from the transformer to the terminal equipment, extensibility of macroscopic compensation is avoided, and compensation precision is greatly improved. Compared with the traditional problem that missing compensation is not easy to perceive, equipment abnormity and a compensation gap can be found in time, a fault point can be rapidly positioned, the pain point that maintenance is difficult to carry out in time is solved, and compensation continuity and stability are guaranteed.

Description

Technical Field

[0001] This invention belongs to the field of power system energy-saving technology, specifically relating to an intelligent grid-connected reactive power management system. Background Technology

[0002] In the use of alternating current, not only is active power needed to perform work, but reactive power is also required to ensure that transformers, motors, and other equipment establish a magnetic field so that they can operate. In my country, reactive power is not charged because it does not perform work, but it incurs line losses on the power grid transmission lines. The reactive power used by electricity users does not necessarily have to come from power plants; power capacitors can be used to compensate for the reactive power of transformers and motors, thereby reducing the current transmitted from the grid.

[0003] The challenge of reactive power management in power grids has been long-standing. Reactive power management responsibility is divided based on ownership demarcation points. Optimal efficiency for both transmission and consumption parties is achieved when both meet performance targets in reactive power management. Statistics show that approximately one-third of large industrial electricity customers fail to meet their power factor (also known as reactive power ratio) targets. Power factor = COS[ATAN(reactive power / active power)]. This means that about one-third of electricity customers fail to meet reactive power management requirements for various reasons. As a result, significant amounts of reactive power are transmitted to the grid, causing losses that must be shared by the grid and power plants. This also leads to localized grid congestion, affecting grid security. Electricity customers, on the other hand, bear more energy losses and incur penalties such as "adjustment fees," resulting in resource waste. Therefore, effective reactive power compensation and management are crucial.

[0004] Currently, most reactive power compensation equipment produced in my country uses microcontroller technology to control the switching of capacitors based on sampled reactive current or reactive power to achieve reactive power compensation. However, this compensation method is a macroscopic compensation, which does not consider abnormal load operation. The switching logic is mostly threshold control, which can easily lead to problems such as missed compensation due to faulty switching that is not easily detected and timely maintenance that is difficult to perform, thus affecting the compensation accuracy. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides an intelligent networked reactive power management system.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A smart network reactive power management system includes a remote terminal, a smart network technology platform, and Type I, Type II, and Type III reactive power compensation devices connected to the original low-voltage power supply system. The Type-I reactive power compensation device is used for reactive power compensation in the low-load range of system transformers, as well as for reactive power compensation of transformer excitation and copper loss; the Type-II reactive power compensation device is used for reactive power compensation in the medium-high load range of system transformers; the Type-III reactive power compensation device is connected to a single electrical equipment with reactive power greater than a specific value, and is used for on-site reactive power compensation of the single electrical equipment; among them, the low load is the load lower than the original reactive power compensation threshold of the system, and the medium-high load is the range where the load is higher than the low load of the system. The intelligent networked technology platform collects the power consumption parameters of power customers in real time, analyzes the power consumption parameters, determines the compensation position according to the analysis results, and sends control instructions to the corresponding reactive power compensation device through the remote transmission terminal according to the compensation position; each reactive power compensation device then transmits the digitized reactive power, active power, voltage, current, and power factor to the intelligent networked technology platform through the remote transmission terminal.

[0007] Preferably, the Type-I reactive power compensation device includes a remote cloud control and current control module; the electrical parameters are collected through the remote cloud control and current control module, and the electrical parameters are digitized, and the digitized electrical parameters are transmitted to the intelligent networked technology platform through the remote transmission terminal; the electrical parameters include the reactive power QA-I, active power PA-I, voltage UA-I, current IA-I, and power factor COS(θA-I) of phase A, where A in A-I represents phase A and I represents the Type-I device.

[0008] Preferably, the Type-I reactive power compensation device includes a full electrical parameter sensor with RS485 communication function, a micro multi-functional electric meter with RS485 communication function, a power capacitor bank, a current three-segment controller K1, and a remote cloud control switch K2; the Type-I reactive power compensation device is connected to the remote transmission terminal through the RS485 communication interface. When the user transformer is operating at low load or no load, the Type-I reactive power compensation device compensates for the transformer excitation reactive power according to the principle of over-compensation of reactive power through K1 control; when the transformer is operating at medium load or high load and the power factor of the original reactive power compensation effect is close to 1, the transformer excitation reactive power is compensated through K2 control.

[0009] Preferably, the Type-I reactive power compensation device automatically controls to achieve reactive power compensation according to the set value, specifically as follows: Control function: K1 = i1 < IL set; Where: i1 is the current in the transformer H1, I L set is the pre-set current, and K1 = i1 < IL set means that when the condition i1 < I L is satisfied, the relay K1 outputs a closed state; When K1 is closed, the contactor KM is closed, and the reactive power Q compensated by the capacitor 补差量Output to the low-voltage bus; the reactive power compensation is transmitted to the intelligent connected technology platform through the DTS2377 meter and remote terminal; Transformer excitation reactive power compensation function: Q_magnetic compensation = Q_magnetic compensation difference - Q_operating point; Where: Q_magnetic compensation is the reactive power compensation function of transformer excitation; Q_compensation amount is the capacity of the power capacitor after equipment commissioning, in kilovars, which is related to the capacity of the transformer; Q_operating point represents the reactive power of the transformer at the operating point G after compensation. At this point, the reactive power of the transformer excitation was compensated.

[0010] Preferably, the method for setting the control parameter IL and obtaining the capacitor capacity parameter Q compensation amount is as follows: The IL setting is based on the original reactive power compensation locking current multiplied by the transformer ratio setting parameter. The Q compensation amount is selected based on the compensation amount of the transformer capacity, according to the following formula: set up For reactive power data of power supply substations, set Reactive power data before reactive power compensation for users changing their operating point; set up ; Therefore: Q_compensation amount = (1 / 96) × ; In the above formula, a single natural number for k, i, and j is equivalent to a time unit of 15 minutes. It is the sum of the reactive power of high-voltage transmission lines, the excitation reactive power of power user transformers, and the copper loss reactive power of transformers.

[0011] Preferably, the Type I reactive power compensation device performs remote control compensation based on the calculation results of the remote platform, as follows: control function ; The KM contactor is closed by the closing command issued by the platform, and the capacitor is put into operation. At this time, the reactive power to compensate the low voltage bus is Q compensation amount. Transformer excitation reactive power compensation function: Q_magnetic compensation = Q_interference compensation - Q_operating point When Q_compensation > 0, it represents the reactive power of the compensation transformer excitation; the remaining compensation amount compensates for the reactive power of the load. When Q compensation is less than 0, the compensation amount fully compensates for the load, and the reactive power of this compensation is recorded in the platform in real time.

[0012] Preferably, the Type II reactive power compensation device is a miniature multi-function meter with RS485 communication function.

[0013] Preferably, the Type III reactive power compensation device includes a miniature multi-function meter with RS485 communication function, a power capacitor bank, and a current three-segment controller.

[0014] The intelligent networked reactive power management system provided by this invention has the following beneficial effects: This invention addresses the problems of traditional single-chip microcomputer macro compensation, threshold control's difficulty in detecting missed compensation, untimely maintenance, and low compensation accuracy through layered precise compensation and intelligent closed-loop management. It simultaneously improves both compensation efficiency and operational efficiency. The system employs three types of differentiated compensation devices (Type I, II, and III) to cover full-load scenarios and single-unit heavy loads, breaking the limitations of traditional single-threshold control. Type I compensates for low loads below the original compensation threshold and for transformer excitation and copper loss reactive power, filling the blind spot of traditional low-load compensation. Type II handles medium-to-high load reactive power demands, and Type III provides on-site compensation for single-unit large loads. This layered precise energy compensation from transformer to terminal equipment avoids the coarseness of macro compensation and significantly improves compensation accuracy.

[0015] Meanwhile, relying on the intelligent connected vehicle technology platform, a real-time closed-loop management system is constructed. The platform dynamically collects and analyzes power consumption parameters, accurately determines the compensation location, and issues commands through remote terminals. This replaces the fixed switching logic of traditional single-chip microcomputers, adapting to abnormal load operating states and adjusting compensation strategies in real time to reduce switching errors and missed compensation. Each compensation device transmits digitized power, voltage, and current data back to the platform, enabling visualized monitoring of the compensation effect. Compared to the difficulty in detecting missed compensation with traditional methods, this system can promptly identify equipment anomalies and compensation gaps, quickly locate fault points, solve the pain point of untimely maintenance, and ensure the continuity and stability of compensation. Attached Figure Description

[0016] To more clearly illustrate the embodiments and design schemes of the present invention, the accompanying drawings required for this embodiment will be briefly described below. The drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is the electrical wiring diagram of the intelligent networked reactive power management system of Embodiment 1 of the present invention; Figure 2 Wiring diagram for the electrical application of Type I reactive power compensation equipment; Figure 3 Diagram illustrating the intelligent connected reactive power management system platform; Figure 4 Wiring diagram for the electrical application of Type II reactive power compensation equipment; Figure 5 Wiring diagram for electrical application of Type III reactive power compensation equipment. Detailed Implementation

[0018] To enable those skilled in the art to better understand and implement the technical solutions of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and should not be construed as limiting the scope of protection of the present invention.

[0019] Example 1 This invention provides an intelligent network-connected reactive power management system, which is mainly used for reactive power management of power customer power grids. The system consists of reactive power compensation equipment, remote transmission terminals and intelligent network technology platform, and operates in the energy performance contracting (EMC) model, aiming to greatly alleviate the problem of reactive power management of power grids.

[0020] Specifically, such as Figure 1 As shown, the system adds Type I, Type II and Type III reactive power compensation devices to the original low-voltage power supply system. The electrical parameters of these three types of reactive power compensation devices have been digitized and can be transmitted to the intelligent network technology platform through a remote terminal. Figure 1 In the diagram, G(Q,P) represents the operating point at the user's side (dashed line), where Q and P represent the reactive power and active power delivered by the transformer at that operating point, respectively. .

[0021] Among them, Type I reactive power compensation equipment is used for low-load compensation and transformer excitation and copper loss reactive power compensation in the system transformer; Type II reactive power compensation equipment is used for high-load reactive power compensation in the system transformer; Type III reactive power compensation equipment is connected to a single electrical device with a load reactive power greater than a specific value for local reactive power compensation of the single electrical device. Specifically, low load refers to the load below the original reactive power compensation threshold of the system, and medium-high load refers to the range where the load is higher than the low load of the system.

[0022] The intelligent connected technology platform collects electricity consumption parameters from power customers in real time, analyzes these parameters, determines the compensation location based on the analysis results, and sends control commands to the corresponding reactive power compensation equipment through a remote transmission terminal based on the compensation location. Each reactive power compensation equipment then transmits the digitized reactive power, active power, voltage, current, and power factor to the intelligent connected technology platform through the remote transmission terminal.

[0023] The advantages of this invention are: First, this invention configures dedicated compensation equipment for different load scenarios: Type I equipment compensates for low load, excitation and copper loss reactive power of transformers, solving the problem of failure of the original compensation equipment in the low load section; Type II equipment compensates for medium and high load reactive power, relying on modular intelligent capacitors to adapt to load fluctuations; Type III equipment compensates for single high load equipment on-site, reducing bus disturbance and feeder line loss. These three types of equipment cover the entire load range and equipment type, filling the original compensation dead zone.

[0024] Secondly, collaborative control is achieved through a remote intelligent network technology platform: the compensation results of the three types of equipment are uploaded to the platform in real time. The platform combines parameters such as power factor and reactive / active power to dynamically coordinate the output of the equipment, avoiding overcompensation or undercompensation. At the same time, the Q compensation parameter is evaluated and corrected in a timely manner through algorithms to ensure long-term operating efficiency and solve the problem of the original compensation equipment "working alone" and lacking overall coordination.

[0025] This system can effectively improve the power factor compliance rate and reduce users' "adjustment electricity bill" expenses; reduce reactive power transmission losses in the power grid and improve the power grid's transmission capacity; endow reactive power compensation electricity with commodity attributes, attract social capital in conjunction with the energy performance contracting model, and promote the professionalization of reactive power management; in addition, it can provide 96 basic data points for energy management, help save energy and reduce carbon emissions, and is predicted to significantly save electricity costs and electricity consumption, and reduce standard coal consumption.

[0026] Overall, the system, through layered precise compensation and intelligent closed-loop management, not only avoids many drawbacks of traditional compensation, but also achieves an upgrade in reactive power compensation from macro to micro and from static to dynamic. This significantly improves the accuracy and reliability of reactive power compensation, reduces grid line losses and user energy consumption, reduces adjustment electricity costs, and alleviates local grid blockages, thus providing support for the safe and stable operation of the power grid and the optimization of benefits for both power supply and consumption parties.

[0027] The following provides further explanation of the three types of reactive power compensation devices.

[0028] (1) Functional description of Type I reactive power compensation equipment: 8) Main uses In the original low-voltage power supply system, the existing reactive power compensation equipment was already in operation. However, due to various factors, the power factor assessment failed to meet the standards, such as the transformer operating under low load or no-load conditions. The compensation effect of the original reactive power compensation equipment was poor. The use of Type I reactive power compensation equipment can better meet the compensation requirements. Its electrical application wiring diagram is as follows: Figure 2 As shown.

[0029] 9) Establish a platform graphical analysis diagram based on real-time transformer operating point data. The transformer operating point data (under normal operating conditions of the original reactive power compensation equipment) consists of the reactive power and active power supplied by the transformer in real time, denoted as G(Q,P), where G represents the operating point, Q represents the reactive power, and P represents the active power. The vertical axis Q represents the reactive power supplied by the transformer (actually equal to the reactive power load of the distribution area minus the original reactive power compensation load), and the horizontal axis P represents the active power supplied by the transformer, thus forming a two-dimensional plane Q0P, which further forms... Figure 3Diagrammatic analysis of the intelligent networked reactive power energy management system platform shown. The horizontal axis of this plane (under the condition that the original reactive power compensation equipment works automatically) moves up and down with different reactive power compensation capacities, simplifying the platform's diagrammatic analysis in the operation and management process of reactive power补差 and providing a visual effect.

[0030] Through Figure 1 Voltage sampling and current sampling by the current transformer H1 in [], the electrical parameter sensor transmits the digitized electrical parameters to the platform through the remote terminal 1. The electrical parameters include the reactive power QA-I, active power PA-I, voltage UA-I, current IA-I, and power factor COS(θA-I) of phase A. The A in A-I above represents phase A, and I represents type I reactive power compensation equipment for the platform to perform operation and identification.

[0031] Under the condition of balanced three-phase power consumption, Q = 3QA-I and P = 3PA-I at the working point G(Q, P).

[0032] The characteristics of establishing this analysis diagram are: 1. Simplify the in-depth description of reactive power compensation analysis and make the description more accurate. 2. It is a tool for simplifying the platform algorithm; 3. Facilitate the analysis of the internal relationship between the dynamic balance of reactive power compensation and the monthly weighted power balance. 4. This template has a visual effect when analyzing the reactive power compensation principle and compensation scheme, avoiding the use of cumbersome formulas to describe abstract calculations. 5. Any result obtained on the visual interface of this template can be conveniently converted into a mathematical model or expression when needed.

[0033] 10) Working principle of type I reactive power compensation equipment for compensating reactive power The working point G of the transformer is at the lower left of L6 in Figure 3 and when Q > 0 at point G (when Q > 0, it means the load is an inductive load and capacitive reactive power needs to be compensated), Figure 2 in the current three-segment controller in [], when i1 < IL, it meets the condition of the control function K1, and the capacitor is automatically put into operation for compensation. Here, il is the current in the current transformer H1.

[0034] The three-segment controller is internally set with segment parameters IL and IH. IL and IH divide the current from the transformer into three segments: low, medium, and high. Only the low segment of IL is used in this invention.

[0035] Control method 1: Automatic control based on the set value 11 Control function: (1) Among them: i1 is the current in the transformer H1, and IL setting is the current set in advance. When the condition i1 < I L is met, the relay K1 outputs a closed state, and when il >= IL, the relay disconnects.

[0036] When K1 is closed, contactor KM is closed, and the reactive power Q compensated by the capacitor is released. 补差量 The output is sent to the low-voltage bus. The compensated reactive power is transmitted to the intelligent connected technology platform via the DTS2377 meter and remote terminal.

[0037] ② Transformer excitation reactive power compensation function: Q_magnetic compensation = Q_compensation difference - Q_operating point (2) Where: Qcompensation is the transformer excitation reactive power compensation function (actually also includes the transformer's copper loss reactive power and the reactive power of the high-voltage feeder from the power supply transformer to the user transformer), Qcompensation is the capacity of the power capacitor after equipment commissioning, in kilovars, and it is related to the transformer's capacity. Qoperating point represents the reactive power of the transformer's operating point G after compensation.

[0038] At this point, the reactive power of the transformer excitation was compensated.

[0039] ③ Methods for setting control parameter IL and obtaining capacitor capacitance parameter Q differential. The IL setting is based on the locking current of the original reactive power compensation equipment multiplied by the transformer ratio setting parameter. The Q compensation amount is selected based on the compensation amount of the transformer capacity, or it can be selected according to the following formula: set up For reactive power data of power supply substations, set The reactive power data is provided before the user changes the operating point and the reactive power compensation is provided (i.e., the Type I, Type II, and Type III reactive power compensation devices have not entered the reactive power compensation state). set up (3) Therefore: Q_compensation amount = (1 / 96) × (4) In the above formula, a single natural number for k, i, and j is equivalent to a time unit of 15 minutes. The physical meaning of reactive power compensation is the sum of the reactive power of high-voltage transmission lines, the excitation reactive power of power user transformers, and the reactive power of transformer copper losses. Its numerical meaning is the sum of the reactive power at 96 points on the substation outgoing lines minus the sum of the reactive power at 96 points on the low-voltage outgoing lines (operating points) of the power customer transformers. The difference, divided by 96, is the reactive power compensation amount required for Type I reactive power compensation equipment.

[0040] At the low end of the user transformer load, the line reactive power is very small, and the copper loss reactive power is also very small when the load is small. The sum of the two is much smaller than the transformer excitation reactive power. Since excitation reactive power is the main aspect of the present invention to solve the contradiction, these three types of reactive power are defined as excitation reactive power in the present invention.

[0041] Control Method Two: Implement remote control to compensate for discrepancies based on the calculation results from the remote platform. If the transformer is operating in the medium load range, assuming that the original reactive power compensation effect is very good and the power factor is close to 1, this also meets the conditions for the Type I equipment to be put into operation. By remotely controlling the closing of K2, the excitation reactive power of the transformer can also be compensated.

[0042] ① Control function: (5) Upon receiving a command from the platform, the KM contactor engages, putting the capacitor into operation. At this point, the reactive power supplied to the low-voltage bus is Q, representing the compensation amount. The transformer's operating point must be located to the upper right of L6.

[0043] ② Transformer excitation reactive power compensation function: Q_magnetic compensation = Q_compensation difference - Q_operating point (6) When Q_magnetic compensation > 0, the reactive power at the Q_operating point is not equal to 0. Part of the reactive power compensation compensates for the excitation reactive power of the transformer, and part of it compensates for the load reactive power (see equation 6 above).

[0044] When Qcompensation < 0, the compensation amount fully compensates for the load. This reactive power compensation is recorded in the platform in real time.

[0045] Through the above process, this invention introduces the concept of timing for reactive power compensation. This means that reactive power compensation or adjustment is time-sensitive; that is, capacitive reactive power can only be compensated when inductive reactive power is present during power consumption, and vice versa. In other words, reactive power compensation cannot miss its opportune moment; if the opportunity is missed, it cannot be compensated, and the effectiveness of reactive power compensation or adjustment is diminished. The original reactive power compensation equipment was designed for transformer substations. Due to various reasons, the original equipment missed reactive power compensation during the required time, which is the main reason why about one-third of customers fail to meet reactive power assessment standards.

[0046] Once the concept of reactive power compensation timing is established, control scheme two is naturally suitable for transformers operating in high-load areas. If the user's transformer operating point falls within... Figure 3 If the active power axis is below the active power axis, it indicates that the system's power consumption is capacitive, and the equipment needs to add inductive reactive power compensation function.

[0047] 4) Evaluation methods and correction of Q-complement parameter For a low-voltage power supply system in operation, there are specific operating rules. These rules are formed by market changes or seasonal changes. Since the capacity of the compensation capacitor cannot be changed continuously, in order to achieve good compensation effect and economic benefits, the real-time evaluation of the Q compensation parameter and the adjustment of the compensation capacity of the compensation equipment become a routine maintenance task after the reactive power management system is put into operation.

[0048] The parameter evaluation method is: ① Q compensation amount = (1 / 96) × (7) The platform can automatically generate a Q 补差量 value every day.

[0049] Formula (7) has two functions: Function 1: In Type I equipment, the Q of the equipment can be automatically tested through the platform 补差量 , and after the test, the capacitance of the equipment capacitor is configured according to this parameter, and the equipment starts to work normally.

[0050] Function 2: After the equipment starts to work normally, as can be seen from Formula (3), the reactive power of the substation outgoing line should be close to 0, and COSθ should be close to 1, which is the most ideal situation for control; by detecting Q 补差量 it should not differ much from the above-mentioned capacitor configuration amount, and the platform outputs a Q 补差量 every day, which can detect the operation status of Type I equipment.

[0051] It shows that when a mutation is detected in Q 补差量 , as can be seen from Formula (3), it indicates that the operating conditions of the transformer have changed. Through platform analysis, it is determined whether the capacitance of the capacitor of Type I equipment needs to be adjusted.

[0052] ② (8) COSθ is the power factor of the substation power supply; ATAN is the arctangent function in the spreadsheet; An average value of COSθ is also generated every day.

[0053] Select a corresponding Q 补差量 value within the range of COSθ assessment <COSθ < 1, and perform phased adjustment and correction on this value to ensure that the management system is in a better working state, which is a goal that the original compensation system cannot achieve.​​​​​​​The above describes the working situation of only one transformer substation. For a power customer with several transformers, in addition to the platform needing to manage the compensation work of each substation, it also needs to manage the compensation of reactive power of transformer excitation, such as Type I equipment. In other words, it also needs to manage the reactive power aggregation of the high-voltage section.

[0056] (2) Functional description of Type II intelligent reactive power compensation equipment: When the transformer is operating at medium to high load levels, the Type II reactive power compensation device can effectively meet the compensation requirements. The electrical wiring diagram of the Type II intelligent capacitor reactive power compensation device is shown below. Figure 4 As shown. Aside from the digital components, other parts of this Type II product, such as the intelligent capacitor module, are freely combinable from controllers and modular intelligent capacitors. It is well-suited for reactive power compensation in existing low-voltage power systems and also suitable for reactive power compensation in newly built power systems. The Type II intelligent reactive power compensation device is mainly used for systems with significant reactive power deficits.

[0057] Both the intelligent capacitor and the original reactive power compensation product are manufactured according to the standard "GB / T-15576-2008 Low-voltage complete reactive power compensation device", and have the same dead zone. The advantage of this intelligent capacitor is that it has intelligently packaged the power capacitor, added an intelligent chip inside the package, and used an electronic switch instead of the original contactor to disconnect and connect the capacitor. The packaged capacitors are connected by network cable instead of the original wire connection.

[0058] In an existing low-voltage power supply system, the function of reactive power compensation can be achieved simply by connecting a multi-functional energy meter with RS485 communication capability between the smart capacitor and the power line. The reactive power QⅡ of the meter (which also belongs to reactive power compensation) is transmitted to the platform through a remote terminal to form part of the reactive power management system.

[0059] Selection of capacitor capacity QⅡ for Type II intelligent reactive power compensation equipment: To describe the calculation method of the supplementary capacity QⅡ of Type II equipment, it is necessary to introduce the design function and usage environment of Type II equipment, and also refer to the design function and usage environment of Type I equipment, as well as the ideal interface for the two types of equipment to work together.

[0060] 1) Explanation of the conditions for calculating QⅡ ① Further explanation of the above formula (4) Q_compensation amount = (1 / 96) × (4) This formula is based on the compensation amount required by the power system measured by the platform (where data collection is working normally) under low load conditions, when Type I, Type II, and Type III equipment have not participated in the compensation work. The compensation amount Q measured at this time is the compensation capacity QⅠ that Type I equipment needs to be configured with.

[0061] 12. Based on the location of the transformer operating point G(Q,P) mentioned above (see...) Figure 1 Defined at the low-voltage output end of the transformer), Type I and Type II equipment are connected sequentially to the busbar after the operating point position, and Type III equipment is connected to a power supply feeder with a large load at the end of the busbar. Any differential compensation equipment will affect the change of the operating point G(Q,P).

[0062] ③ The compensation quantity QⅠ of Type I equipment mainly completes the reactive power compensation between the user transformer outgoing line and the power supply transformer outgoing line (its main function is reactive power compensation for the excitation of the user transformer). The ideal interface for the compensation of Type I equipment is: before the compensation of Type I equipment, the operating point of the transformer G(Q,P) = G(0,P), that is, the power factor of the operating point is equal to 1. This is also the main function that Type II equipment will complete after it is put into operation.

[0063] 13) Formula and explanation for calculating QⅡ Q_compensation = Q_Ⅰ + Q_Ⅱ + Q_Ⅲ (9) Formula (9) holds true under the following conditions: It is assumed that Type I, Type II, and Type III equipment did not participate in the compensation work. Formula (9) is applicable to the calculation of reactive power compensation for these three models of equipment. Instructions for using formula (9): Under the above conditions, the Q compensation amount of the platform test is allocated by the three models of equipment in the order of type I, type II and type III, respectively, with compensation amounts QⅠ, QⅡ and QⅢ.

[0064] 3) Method for calculating QⅡ: Since the Type III equipment has not yet been allocated supplementary capacity, QⅢ=0. And since QⅠ has been configured with supplementary capacity, when testing the Q supplementary amount on the platform, depending on whether the Type I equipment has been running with supplementary capacity, this formula (9) can be divided into the following two forms: ①Q compensation amount = QⅠ + QⅡ, at this time, neither type I nor type II equipment has compensation.

[0065] That is, QⅡ = Q_compensation amount - QⅠ, where QⅠ is a known quantity, and Q_compensation amount is provided by the platform test.

[0066] ②Q_compensation amount = Q_I + Q_II. At this time, the Type I equipment has been put into compensation work, and the operating point of the transformer has changed (corresponding to the compensation amount of Q_I). Therefore, the formula should be corrected to: Q_compensation amount = Q_II.

[0067] That is: QⅡ = newly obtained Q compensation amount (10) Formula (10) means that when the Type I equipment has been put into compensation work, the platform can directly measure the compensation capacity required by the Type II equipment.

[0068] (14) Functional description of Type III reactive power compensation equipment This type of equipment is mainly used for reactive power compensation of a single unit, commonly referred to as local compensation. The wiring diagram for the Type III reactive power compensation equipment is as follows: Figure 5 As shown. Type III reactive power compensation equipment is mainly used for local reactive power compensation of a single electrical device.

[0069] When on-site compensation is required, the Type III reactive power compensation equipment can effectively meet the compensation requirements. The key reason why it can effectively meet the requirements is that this compensation measure can reduce the reactive power variation caused by large disturbances on the power supply bus, and can also save the line loss of the equipment in the power supply feeder, which can be calculated.

[0070] The difference between this device and Type I is that it lacks remote control and a transformer operating point test sensor. Local compensation is an important component of reactive power compensation. Although the promotion of local compensation has been slow for various reasons over the years, this Type III device, as part of a reactive power compensation solution, is expected to increase the promotion of local compensation.

[0071] Type I, Type II, and Type III reactive power compensation devices can be configured in terms of the number of units and basic reactive power compensation capacity as needed. When the compensation devices are working, the data collected can be displayed on the platform. Through data analysis and calculation on the platform, the electrical parameters of various relevant points in the low-voltage power supply system can be obtained. Through data processing, the real-time status of power supply operation can be known, thereby obtaining control parameters and equipment debugging parameters. For example, after analyzing the operating data, the platform can discover the pattern of power supply operation to determine whether to perform remote control according to timing parameter programming or to achieve local real-time control according to current three-segment control.

[0072] The operation of this system can take over most of the on-site staff's shift work.

[0073] Examples of application methods for system platform diagram analysis (1) Data analysis of the intelligent connected reactive power management system platform, such as Figure 3 As shown In the figure, positive vertical values ​​represent the inductive reactive power provided by the power transformer to the load after compensation by the original reactive power compensation equipment, denoted by the letter Q, with the unit being kilovar (kVar) and the scale being ×10. Negative values ​​represent the capacitive reactive power compensation amount. The horizontal axis represents the active power provided by the transformer to the load, with the unit being kilowatt (kW) and the scale being ×10.

[0074] (15) Diagrammatic Explanation: L1: The operating state line of the transformer when the power factor is COSθ = 0.707 during online operation. The operating point G determined by the active and reactive power output of the transformer satisfying this condition must fall on L1, as shown by points G1, G2, and G3 in the figure. Different power factors (COSθ) of the transformer result in corresponding operating state lines L1΄: Q = P × TAN(θ). The region of the transformer's operating point must fall to the lower left of the transformer's full-capacity curve L5.

[0075] L2 and L3 are the transformer operating power factor assessment lines COSθ2=0.85 and COSθ2=0.9 respectively (the assessment standards differ for different types of electricity use). There is also an assessment line COSθ=0.8, which is not shown in the diagram. Figure 3 Its position does not change due to changes in other factors.

[0076] L5: Transformer full-capacity curve.

[0077] L6: The load domain boundary curve corresponding to the lockout current of the original reactive power compensation equipment connected to the transformer, also known as the dead zone boundary line that the original reactive power compensation equipment cannot compensate for. This dead zone is located to the lower left of L6.

[0078] (16) Diagram example: Example 1: Assuming the transformer is operating at point G2 in the diagram, the capacitive reactive power can be directly supplemented by 70 kVar of readings downwards to achieve the assessment standard of COSθ=0.85. If the capacitive reactive power is supplemented by 100 kVar, the assessment standard of COSθ=0.9 can be achieved. To achieve the target value of COSθ=0.95, the reactive power needs to be supplemented by 130 kVar.

[0079] The above 130 kVAR - 100 kVAR = 30 kVAR, multiplied by the compensation time, is the reactive power compensation reserve for the dead zone. This power is beneficial to achieving the monthly average power factor assessment target.

[0080] During actual operation of a transformer, L1΄ changes with the change of θ. With the digitally upgraded platform, L1΄ can be displayed on the screen through image processing. The image positions of L2, L3, and L4 remain unchanged, and the graphical algorithm remains unchanged. Graphical values ​​can be obtained in real time. Through automatic control or timely adjustment of control parameters, the system can be compensated for inappropriate behavior. The original reactive power compensation equipment did not have this intuitive intermediate quantity display function, nor did it have the function of defect elimination and adjustment. This is the reason why about one-third of the power customers fail to meet the power assessment standards.

[0081] Example 2: When a power customer's electricity consumption is at low load or suspended due to changes in market factors, the transformer's light-load operating point falls to the lower left of the L6 dead-zone curve because the original reactive power compensation equipment has a dead zone. The platform's graphical method is as follows: Figure 3The diagram shows small and medium-sized rectangular grids, each representing a differential power capacity of 10 kvar. Assuming the transformer's operating point falls on L1, corresponding to an active power of 11.2 kWh, its reactive power consumption is also 11.2 kvar. At this time, the original reactive power compensation equipment is in a stopped state. After a period of time T, the reactive power accumulated from the differential compensation will be substantial. Combined with the reactive power from transformer excitation and copper losses, the ratio of reactive power absorbed from the grid to active power will be relatively large, resulting in a low power factor. This often leads to power factors falling below the assessment standard, sometimes even as low as 0.4. Such adjustments to electricity charges exceeding 100% are common, significantly increasing electricity costs for customers. Based on the data of the transformer operating in the original compensation dead zone, the platform can graphically obtain the reactive power compensation required to reach a power factor of 0.95, which is 4.9 kVAR - 11.2 kVAR = 6.3 kVAR. This small-capacity reactive power compensation can be completed using a Type I reactive power compensation device.

[0082] In addition to compensating for the reactive power that should be compensated in the dead zone, the Type I reactive power compensation equipment also has the function of compensating for the reactive power of the transformer and the line by using the principle of reactive power overcompensation, thereby achieving a better compensation effect.

[0083] Example 3: Assume the transformer is operating in... Figure 3 At point G3, a direct downward reading from the diagram shows a reactive power compensation of 110 kV to achieve the COSθ=0.85 standard. Compensating 160 kV would achieve a COSθ=0.9 standard, and compensating 200 kV would achieve a COSθ=0.95 target. This necessitates the use of a Type II reactive power compensation device. This type of device has strong compensation capabilities and is convenient for capacity combination and installation, featuring modular design and automatic networking. The need to put this large-capacity device into operation indicates a severe deficiency in the original reactive power compensation capacity or a significant increase in load compared to the original.

[0084] Example 4: When local compensation is required based on the specific requirements of the electrical equipment, a Type III reactive power compensation device can be used. This device has a testing function, and the compensation amount can be selected as needed. Local compensation can reduce the apparent current of the power supply feeder (cable), and the energy savings corresponding to the reduced apparent current can be calculated through the platform.

[0085] Example 5: For power customers connected to several transformers through high-voltage distribution, the reactive power consumption of multiple transformers is interconnected when they are running, which better demonstrates the superiority of the system's interconnected management. The original reactive power compensation equipment only works on a single transformer and does not have an interconnected function.

[0086] The calculation process and equipment characteristics illustrated above fully demonstrate that the original reactive power compensation equipment must meet certain conditions to achieve a better compensation effect. In other words, the failure to meet the conditions for the normal operation of the original reactive power compensation equipment is the main reason why approximately one-third of electricity customers have substandard power factors.

[0087] The main working principle of this invention is as follows: the platform obtains the electricity consumption parameters of the power customer in real time, and after analysis, it knows where there is a lack of reactive power. Where there is a lack of reactive power, the platform commands the "reactive power compensation" equipment in that part to make up the difference, thus completing the purpose of reactive power compensation.

[0088] Based on predictions, the method provided by this invention can save a large industrial power customer in a certain province 1 billion yuan in electricity expenses annually, increase the power grid company's transmission capacity by 10% to 20%, save the power customer 337 million kWh of electricity [1501.95 × 54% × 37% × 10% × 10.63%], equivalent to 41,400 tons of standard coal, and save the power grid company 215 million kWh of electricity {[1391.98 × 54% × 37% / (1-6%)] × 6% × 10.63%}, equivalent to 26,400 tons of standard coal. For many years, due to the long-standing problem of reactive power compensation, and due to technical and management reasons, this energy has been wasted, and this is currently the general level nationwide.

[0089] This invention provides an intelligent networked reactive power management system, which can be used as a technical solution for the digital upgrade and transformation of reactive power compensation equipment already in operation, and can also be used as a technical solution to promote the transformation of traditional reactive power compensation industry to new industrialization.

[0090] The intelligent connected reactive power management system proposed in this invention has the following advantages: 1. By introducing the "Energy Performance Contracting" model promoted by the state, a benefit settlement interface is provided for social capital to enter the electricity market to carry out energy-saving and reactive power compensation businesses, which can solve the investment problem of online equipment upgrades and renovations.

[0091] 2. This endows the reactive power compensation with commodity attributes, that is, it assigns a unit price to the reactive power compensation, thereby promoting and improving the progress of energy conservation in the electricity market.

[0092] 3. Reactive power management has become more professional and refined, solving many difficulties that electricity customers themselves struggle to overcome in achieving power consumption targets, and further improving the pass rate of power factor assessment.

[0093] 4. It can save a lot of resources and reduce electricity costs for electricity customers.

[0094] 5. Further improve the transmission efficiency of the power grid and reduce the construction cost of the power grid.

[0095] 6. All the relevant physical quantities and economic indicators mentioned above have been quantified to promote the market-oriented operation of energy conservation and carbon emission reduction.

[0096] 7. It can also provide 96 points of basic electricity data for energy efficiency management.

[0097] It should be noted that the specific embodiments described above enable those skilled in the art to more fully understand the present invention, but do not limit the present invention in any way. Therefore, although the present invention has been described in detail in this specification and embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the present invention; and all technical solutions and improvements that do not depart from the spirit and scope of the present invention are covered within the protection scope of the present invention patent. No reference numerals in the claims should be construed as limiting the scope of the claims. Any simple variations or equivalent substitutions of technical solutions that can be readily obtained by those skilled in the art within the scope of the technology disclosed in the present invention are within the protection scope of the present invention.

Claims

1. An intelligent networked reactive power management system, characterized in that, It includes a remote terminal, an intelligent networking technology platform, and Type-I reactive power compensation equipment, Type-II reactive power compensation equipment, and Type-III reactive power compensation equipment connected to the original low-voltage power supply system; The Type-I reactive power compensation equipment is used for low-load compensation in the system transformer, excitation and copper-loss reactive power compensation of the transformer; the Type-II reactive power compensation equipment is used for medium-high load reactive power compensation in the system transformer; the Type-III reactive power compensation equipment is connected to a single electrical equipment with load reactive power greater than a specific value and is used for on-site reactive power compensation of the single electrical equipment; among them, the low load is the load lower than the original reactive power compensation threshold of the system, and the medium-high load is the interval where the load is higher than the low load of the system; The intelligent networking technology platform collects the electricity consumption parameters of power customers in real time, analyzes the electricity consumption parameters, judges the compensation position according to the analysis result, and sends a control instruction to the corresponding reactive power compensation equipment through the remote terminal according to the compensation position; each reactive power compensation equipment then transmits the digitized reactive power, active power, voltage, current, and power factor to the intelligent networking technology platform through the remote terminal.

2. The intelligent networked reactive power management system according to claim 1, characterized in that, The Type-I reactive power compensation equipment contains a remote cloud control and current control module; the electrical parameters are collected through the remote cloud control and current control module, and the electrical parameters are digitized. The digitized electrical parameters are transmitted to the intelligent networking technology platform through the remote terminal; the electrical parameters include the reactive power QA-I, active power PA-I, voltage UA-I, current IA-I, and power factor COS(θA-I) of phase A, where A in A-I represents phase A and I represents Type-I equipment.

3. The intelligent networked reactive power management system according to claim 1, characterized in that, The Type-I reactive power compensation equipment includes a full electrical parameter sensor with RS485 communication function, a micro multi-functional electric meter with RS485 communication function, a power capacitor bank, a current three-segment controller K1, and a remote cloud control switch K2; the Type-I reactive power compensation equipment is connected to the remote terminal through the RS485 communication interface; When the user transformer is operating at low load or no load, the Type-I reactive power compensation equipment compensates the excitation reactive power of the transformer by controlling through K1 according to the principle of reactive power overcompensation; when the load is medium or high and the power factor of the original reactive power compensation effect is close to 1, the excitation reactive power of the transformer is compensated by controlling through K2.

4. The intelligent networked reactive power management system according to claim 3, characterized in that, The Type-I reactive power compensation equipment automatically controls to achieve reactive power compensation according to the set value, specifically as follows: The control function is: K1 = i1 < IL setting; Where: i1 is the current in the mutual inductor H1, I L The setting is the pre-set current, K1 = i1 < IL The setting means that when the condition i1 < I is satisfied L the relay K1 outputs a closed state; When K1 is closed, contactor KM is closed, and the reactive power Q compensated by the capacitor is released. 补差量 Output to the low-voltage bus; the reactive power compensation is transmitted to the intelligent connected technology platform through the DTS2377 meter and remote terminal; Transformer excitation reactive power compensation function: Q magnetic compensation = Q compensation amount - Q working point; Where: Q magnetic compensation is the transformer excitation reactive power compensation function, Q compensation amount is the capacity of the power capacitor adjusted by the equipment, in kvar, related to the capacity of the transformer; Q working point represents the reactive power of the working point G of the transformer after compensation at that time; Thus, the reactive power of the transformer excitation is compensated.

5. The intelligent networked reactive power management system according to claim 4, characterized in that, The acquisition methods of the control parameter IL setting and the capacitor capacity parameter Q compensation amount are as follows: IL setting is set by referring to the original reactive power compensation locked current multiplied by the transformer ratio setting parameter, and Q compensation amount is selected by referring to the compensation amount of the transformer capacity, and is selected according to the following formula: set up For reactive power data of power supply substations, set Reactive power data before reactive power compensation for users changing their operating point; set up ; Therefore: Q_compensation amount = (1 / 96) × ; In the above formula, a single natural number for k, i, and j is equivalent to a time unit of 15 minutes. It is the sum of the reactive power of high-voltage transmission lines, the excitation reactive power of power user transformers, and the copper loss reactive power of transformers.

6. The intelligent networked reactive power management system according to claim 5, characterized in that, The Type-I reactive power compensation equipment implements remote control compensation according to the calculation result of the remote platform, specifically as follows: Control function ； The KM contactor is closed by the closing command issued by the platform, and the capacitor is put into operation. At this time, the reactive power to compensate the low voltage bus is Q compensation amount. Transformer excitation reactive power compensation function: Q_magnetic compensation = Q_interference compensation - Q_operating point When Q_compensation > 0, it represents the reactive power of the compensation transformer excitation; the remaining compensation amount compensates for the reactive power of the load. When Q compensation is less than 0, the compensation amount fully compensates for the load, and the reactive power of this compensation is recorded in the platform in real time.

7. The intelligent networked reactive power management system according to claim 1, characterized in that, The Type II reactive power compensation device is a miniature multi-function meter with RS485 communication function.

8. The intelligent networked reactive power management system according to claim 1, characterized in that, The Type III reactive power compensation device includes a miniature multi-function meter with RS485 communication function, a power capacitor bank, and a current three-segment controller.

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