Efficient energy-saving system of smart power grid

Abstract

The invention relates to the technical field of intelligent power grids, and discloses an efficient energy-saving system of an intelligent power grid. Comprising an intelligent reactive power compensation regulator, a shunt capacitance control switch, a capacitor bank and a three-phase current transformer, the intelligent reactive power compensation regulator comprises a digital quantitative monitoring module and an intelligent computing control module, and the digital quantitative monitoring module collects information in real time and sends the information to the intelligent computing control module, so that the intelligent computing control module generates an optimal output control combination instruction; the shunt capacitance control switch adopts a zero-potential switch, and the zero-potential switch is switched on or switched off when the potential difference between the two ends is approximately zero; and the intelligent reactive power compensation regulator sends the optimal output control combination instruction to the shunt capacitance control switch to control the connection or disconnection of the capacitor bank. Parameters are collected in real time through the digital quantitative monitoring module, an optimal compensation strategy is generated in combination with the intelligent operation control module, and the hysteresis and error problems of traditional simulation control are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of smart grid, and particularly relates to a smart grid efficient energy-saving system. BACKGROUND

[0002] In the field of reactive power compensation at the power user end of the smart grid, traditional reactive power compensation devices generally have problems such as insufficient regulation accuracy, slow response speed, short equipment life, and large impact on the power grid. The existing compensation devices mostly use analog control technology and rely on a single current transformer for single-phase monitoring, which cannot accurately cope with complex scenarios of three-phase load imbalance, resulting in large errors in reactive power calculation and difficulty in improving compensation efficiency. In addition, when the traditional shunt capacitor control switch (such as an AC contactor or a general electronic switch) is turned on or turned off, there is a significant fluctuation in the potential difference between the two ends, which easily produces an impact current, not only damaging the capacitor bank (such as the average service life of existing capacitors being only 2-3 years), but also causing electromagnetic interference to the power grid and surrounding electronic devices, affecting system stability.

[0003] In terms of capacitor bank design, the traditional scheme mostly uses a delta connection, and the neutral point is not effectively grounded, which has safety hazards and insufficient voltage withstand performance, making it difficult to adapt to high-precision compensation requirements. At the same time, there is a lack of deep integration of digital quantitative monitoring and intelligent operation control of the compensation process in the existing technology, which cannot record key parameters such as power factor, active / reactive power in real time and perform dynamic optimization, resulting in lagging compensation strategies and limited energy-saving efficiency.

[0004] Therefore, there is an urgent need for a system to solve at least one of the above problems. SUMMARY

[0005] The present application provides a smart grid efficient energy-saving system, aiming to solve the problem that although there are some improvements in the existing technology for single problems (such as adding overload protection and using hierarchical capacitor banks), there is still no scheme to systematically integrate zero-potential switch technology, three-phase independent current monitoring, Y-type connection capacitor bank neutral point grounding design, and digital intelligent control modules. In particular, the characteristics of zero-potential switch turning on / off when the potential difference is approximately zero, and the precise sampling of three-phase current transformers for each phase load, combined with digital quantitative monitoring and intelligent operation control, have not formed a technical inspiration in the existing technology, and related technologies still remain at the level of single function optimization, without achieving a breakthrough in the overall performance (response speed, regulation accuracy, equipment life, and power grid compatibility) of the compensation system.

[0006] In a first aspect, the present application provides a smart grid efficient energy-saving system, comprising an intelligent reactive power compensation regulator, a shunt capacitor control switch, a capacitor bank, and a three-phase current transformer. The intelligent reactive power compensation regulator comprises a digital quantization monitoring module and an intelligent operation control module, the digital quantization monitoring module collects power factor, active power, reactive power, operating state and fault information in real time and sends them to the intelligent operation control module, so that the intelligent operation control module generates optimal output control combination instructions; The shunt capacitor control switch adopts a zero potential switch which is turned on or turned off when the potential difference between two ends is approximately zero; the three-phase current transformer comprises an A-phase current transformer, a B-phase current transformer and a C-phase current transformer, which are respectively sleeved on the three-phase power supply main circuit, and the corresponding secondary sides are respectively connected with the sampling current input ends of the intelligent reactive power compensation regulator; the capacitor bank adopts Y-type connection design, and the corresponding neutral points are effectively connected with the power supply zero line. The intelligent reactive power compensation regulator controls the access or disconnection of the capacitor bank by sending the optimal output control combination instructions to the shunt capacitor control switch.

[0007] In some embodiments, the system further comprises a wireless control module for realizing wireless signal transmission between the intelligent reactive power compensation regulator and the shunt capacitor control switch, and the intelligent reactive power compensation regulator sends the optimal output control combination instructions to the shunt capacitor control switch through the wireless control module to control the access or disconnection of the capacitor bank.

[0008] In some embodiments, the wireless control module adopts Bluetooth wireless transmission technology, the effective transmission distance is 100 meters, and the capacitance parameters of the capacitor bank are input and recorded by scanning codes, so as to realize wireless signal transmission and parameter configuration between the intelligent reactive power compensation regulator and the shunt capacitor control switch.

[0009] In some embodiments, the system further comprises a main switch and a branch line protection switch; the main switch is an air switch for overall overload protection and temporary isolation; the branch line protection switch adopts an air switch with a nominal current of 1.5 to 2 times the rated current of the corresponding branch line, which is installed in front of the corresponding shunt capacitor control switch, and the branch line protection switch is installed alone or in combination with multiple branch lines with a capacity of less than 5 kilowatts.

[0010] In some embodiments, the measurement data of the traditional transmitting and receiving positions are re-parameterized into midpoint position and offset position parameters, which comprises that the digital quantization monitoring module records and stores the recording time, power factor, operating power factor, active power, reactive power, active power, reactive power, output combination, operating state and fault information in real time, and obtains corresponding emergency disposal information by sending the fault information to a preset emergency disposal end.

[0011] In some embodiments, the zero potential switch ensures that the potential difference across the switch is approximately zero when the switch is turned on or off, thereby avoiding impact on the capacitor bank, the switch assembly and the surrounding equipment, and the power grid.

[0012] In some embodiments, the capacitor bank adopts a new capacitor design and adopts a Y-type connection mode, and the neutral point is effectively connected with the power zero line. During debugging and maintenance, the capacitor bank and the neutral line safety hazards are avoided through detection mechanism.

[0013] In some embodiments, the three-phase current transformer includes an A-phase current transformer, a B-phase current transformer and a C-phase current transformer, which are respectively sleeved on the A-phase line, the B-phase line and the C-phase line of the three-phase power supply main circuit. The corresponding secondary side output ends are respectively connected with the sampling current input ends of the intelligent reactive power compensation regulator. The primary side current of the three-phase current transformer is matched with the main circuit current, and the maximum current of the secondary side is 5A.

[0014] In some embodiments, the intelligent operation control module performs self-checking analysis on the system running state after generating the optimal output control combination instruction, diagnoses the health condition of the device itself, automatically sends an alarm information when detecting an abnormality, and saves the effective parameters in the corresponding device database.

[0015] In some embodiments, the intelligent operation control module supports a sequential output mode or an intelligent control output mode. The sequential output mode is to sequentially connect or disconnect the capacitor banks in the order of the capacitor bank capacity from small to large. The intelligent control output mode is to select to sequentially connect or disconnect according to the comparison between the actual measured reactive power and reactive current values and the preset capacitor values from large to small, or to combine the output through binary value processing and staggered delay. The capacitor values are pre-set by program, manually input or measured by self-checking program and saved in the preset memory.

[0016] The application acquires parameters such as power factor, active / reactive power in real time through a digital quantitative monitoring module, generates an optimal compensation strategy in combination with an intelligent operation control module, so that the reactive power compensation accuracy is significantly improved, and the hysteresis and error problems of traditional analog control are solved. The impact current when the switch is actuated is completely avoided by using a zero-potential switch to turn on / off when the potential difference is approximately zero, the average service life of the capacitor bank is extended from 2 years in the traditional scheme to 20 years, and the interference on the power grid and electronic equipment is reduced. Through independent sampling of A / B / C three-phase current transformers, the three-phase load imbalance scene is accurately responded to, the pertinence of the compensation strategy is improved, and the problem of uneven compensation caused by traditional single-phase monitoring is solved. The capacitor bank is connected in Y and grounded at the neutral point, the voltage withstand performance and safety reliability are improved, and the zero-potential switch and the intelligent control module are used to realize non-impact switching and reduce the equipment failure risk. By recording parameters such as running state and fault information in real time and sending them to the headquarters system, remote monitoring and fault diagnosis are supported, and the operation and maintenance efficiency and the intelligent level of equipment management are improved. At the same time, by using a Y-type capacitor bank, three-phase control can be performed, and the regulation and control accuracy of the three-phase unbalanced circuit is ensured. Therefore, a single-phase capacitor bank is matched to form single-phase regulation and control for single-phase circuits such as household use. In practical application, the average electrical efficiency is more than 99%.

[0017] It should be understood that the foregoing general description and the following detailed description are only exemplary and explanatory, and cannot limit the application. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can be obtained by those skilled in the art without creating laborious work.

[0019] Figure 1 is a reactive power compensation principle diagram provided by the application; Figure 2 is a current and voltage phasor diagram provided by the application; Figure 3 is a power triangle diagram provided by the application; Figure 4 is an internal connection schematic diagram of a first reactive power automatic compensation metronome provided by the application; Figure 5 is an internal connection schematic diagram of a second reactive power automatic compensation metronome provided by the application; Figure 6 is a structural schematic block diagram of an intelligent power grid efficient energy-saving system provided by the application.

[0020] It should be understood that the above general description and the following detailed description are only exemplary and explanatory and are not restrictive of the application. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0022] The flowcharts shown in the drawings are only exemplary and are not necessarily required to include all the contents and operations / steps, and are not necessarily executed in the described order. For example, some operations / steps can be further decomposed, combined or partially merged, so that the actual execution order can be changed according to the actual situation.

[0023] It should be understood that, in order to clearly describe the technical solutions of the embodiments of the present application, in the embodiments of the present application, the terms "first", "second", etc. are used to distinguish the same items or similar items with basically the same functions and effects. Those skilled in the art can understand that the terms "first", "second", etc. do not limit the quantity and execution order, and the terms "first", "second", etc. also do not necessarily mean different.

[0024] It should be understood that the terms used in the present application specification are only for the purpose of describing specific embodiments and are not intended to limit the present application. As used in the present application specification and the appended claims, unless otherwise clearly indicated by the context, the singular forms "a", "an" and "the" are intended to include the plural forms.

[0025] It should also be understood that the term "and / or" used in the present application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes these combinations.

[0026] Some embodiments of the present application will be described in detail below with reference to the accompanying drawings. The following embodiments and features in the embodiments can be combined with each other without conflict.

[0027] In the field of reactive power compensation at the power user end of the smart grid, please refer to Figures 1-3Traditional reactive power compensation devices generally suffer from insufficient control precision, slow response speed, short equipment lifespan, and significant impact on the power grid. Existing compensation equipment mostly employs analog control technology, relying on a single current transformer for single-phase monitoring. This makes it unable to accurately handle complex scenarios of three-phase load imbalance, resulting in large errors in reactive power calculation and difficulty in improving compensation efficiency. Furthermore, traditional shunt capacitor control switches (such as AC contactors or ordinary electronic switches) are prone to generating inrush currents due to significant potential fluctuations when turned on or off. This not only damages the capacitor bank (e.g., the average lifespan of existing capacitors is only 2-3 years) but also causes electromagnetic interference to the power grid and surrounding electronic equipment, affecting system stability.

[0028] In capacitor bank design, traditional solutions often employ delta connections with an ineffective neutral point ground, posing safety hazards and insufficient withstand voltage, making them unsuitable for high-precision compensation requirements. Furthermore, existing technologies lack deep integration of digital quantitative monitoring and intelligent computational control of the compensation process, failing to record key parameters such as power factor and active / reactive power in real time for dynamic optimization. This results in lagging compensation strategies and limited energy-saving efficiency.

[0029] While existing technologies offer some improvements for specific problems (such as adding overload protection and using tiered capacitor banks), no solution has yet systematically integrated zero-potential switching technology, three-phase independent current monitoring, neutral grounding design of Y-connected capacitor banks, and digital intelligent control modules. In particular, the characteristics of zero-potential switching—conduction / deactivation when the potential difference is approximately zero—and the precise sampling of each phase load by three-phase current transformers, combined with digital quantitative monitoring and intelligent computational control, have not provided technological inspiration in existing technologies. These technologies remain at the level of single-function optimization and have not achieved a breakthrough improvement in the overall performance of the compensation system (response speed, control accuracy, equipment lifespan, and grid compatibility).

[0030] like Figures 4-5 As shown, the prior art and this application respectively provide an intelligent reactive power automatic compensation energy-saving device 1' (hereinafter referred to as energy-saving device 1') for power users, including an intelligent reactive power compensation regulator 1, several shunt capacitor control contactors 2, several capacitor banks 3, and a current transformer 4. The intelligent reactive power compensation regulator 1 is provided with a sampling current input terminal, a sampling voltage input terminal, an external AC contactor power bus, several output control lines, and a control circuit (not shown). The sampling current input terminal is connected to the current transformer 4. One end of the sampling voltage input terminal is connected to the power phase line, and the other end is connected to the power neutral line. The external AC contactor power bus is connected to the power phase line. The current transformer 4 is mounted on a power phase line. The output control lines are respectively connected to the shunt capacitor control contactors 2. In this embodiment, the intelligent reactive power compensation regulator 1 has 10 output control lines.

[0031] The energy saver 1' can further comprise a main switch 5 arranged inside the energy saver 1' and a housing (not shown in the figure) covering the energy saver 1'. The intelligent reactive power compensation regulator 1 can be replaced by a programmable controller. The user's main switch 6 and user's meter 7 can be connected before the energy saver 1'.

[0032] In order to prevent the capacitor bank 3 from discharging into the external line and hurting people when power is off, a power-off protection contactor (not shown in the figure) can be arranged in the energy saver 1'. The power-off protection contactor is controlled by the external power supply of the energy saver 1'. The input voltage of the power-off protection contactor can be 380V or 220V, and the contact current is greater than 1.5 times the total current of the energy saver 1'.

[0033] In order to reduce the overcurrent caused by the capacitor when it is connected again after breaking, a normally closed moving contact of a contactor can be used to connect the broken capacitor string to a resistive or inductive load for closed-loop discharge.

[0034] The intelligent reactive power compensation regulator 1 can be a JKG and JKL series intelligent reactive power compensation regulator. The shunt capacitor control contactor 2 can select an input voltage of 380V or 220V, and the rated working current is at least 1.5 times the working current of the capacitor bank 3. The shunt capacitor control contactor 2 comprises a moving contact 20 and a coil 21. When the input voltage of the contactor 2 is 380V, the coil 21 is connected to the phase line of the power supply; when the input voltage of the contactor 2 is 220V, the coil 21 is connected to the zero line of the power supply. In this embodiment, the shunt capacitor control contactor 2 is 10.

[0035] The capacitor bank 3 comprises a first primary capacitor bank and a second primary capacitor bank. The capacitor bank 3 is connected to the power supply through the moving contact 20 of the shunt capacitor control contactor. In this embodiment, the first primary capacitor bank comprises 6 secondary capacitor banks C1-C6 with increasing capacitance values, each secondary capacitor bank comprising three capacitors connected in parallel and having the same capacitance value, and the capacitance value of the next secondary capacitor bank is twice the capacitance value of the previous secondary capacitor bank. That is, a step difference with a gradient of 2N-1 (where N=1-6) is formed between the capacitance values of each capacitor bank.

[0036] The second capacitor bank comprises 4 secondary capacitor banks C7-C10 with the same capacitance value, each secondary capacitor bank comprising three capacitors connected in parallel and having the same capacitance value, and the capacitance value of the capacitor banks C7-C10 is twice the capacitance value of the capacitor bank C6.

[0037] Of course, the first primary capacitor group can also include several secondary capacitor groups with increasing capacitance values, the capacitance value of the latter secondary capacitor group being greater than or equal to the capacitance value of the former secondary capacitor group and less than or equal to the sum of the capacitance values of the former secondary capacitor groups; the second primary capacitor group includes several secondary capacitor groups with the same capacitance value, and the capacitance value of each secondary capacitor group is 1-2 times the maximum capacitance value of the secondary capacitor groups of the first primary capacitor group. The secondary capacitor groups can also be replaced by a single capacitor.

[0038] Of course, the capacitor group 3 can also be composed of several capacitors or capacitor groups with the same capacitance value; if composed of capacitor groups, each capacitor group includes three capacitors in parallel with the same capacitance value.

[0039] The selection of the capacitor group should be determined according to the power factor of the original equipment and the required power factor. When the input voltage is 380V and the capacitors are connected in a triangle, the capacitor shell must be grounded, and when the input voltage is 220V and the capacitors are connected in a star, the capacitor neutral line is connected to the zero line and the shell is grounded.

[0040] In the present embodiment, an external current transformer 4 with a specification of N / 5A is used, N is the maximum current value of the main switch 5, and the maximum current of the secondary of the current transformer 4 is 5A. The external current transformer 4 is sleeved on the power supply phase line, and the original current transformer secondary on the power supply bus and the sampling current input end of the intelligent reactive power compensation regulator 1 can also be connected in series.

[0041] The working principle of the energy saver 1' of the present application is as follows: first, by comparing and analyzing the sampling current and the sampling voltage, the phase difference signal (G type) or the reactive current signal (L type) is obtained. Then when the signal reaches the lower limit of the set value, the closing signal is sent out, and when the signal reaches the upper limit of the set value, the breaking signal is sent out. After the signal is maintained for a delay time, the control circuit in the intelligent reactive power compensation regulator 1 is triggered to drive the contactor to work in a "sequential output" or "intelligent control" mode. The so-called "sequential output" is to turn on or break each capacitor in order from small to large. The so-called "intelligent control" is to compare the actual measured reactive power, reactive current value and the capacitance value (current value) of each capacitor from large to small, and then select the output (turn on or break each capacitor) or combined output (processed by binary number value, and then turned on or broken after staggered delay). The capacitance value (current value) of each capacitor can be "preset" in the program, or manually input one by one, or measured one by one through the "self-checking" program and saved in the memory for calling. The reactive power generated by the motor of the internal electrical equipment of the power user is properly compensated in the user's own main switch. The reactive current forms a loop with the capacitor group in the energy saver and the motor, stores electrical energy and then returns the electrical energy to the motor for use.

[0042] In this embodiment, the energy saver 1' is used in three-phase 380V reactive power compensation for three-phase AC inductive load balancing of three-phase 380V power users.

[0043] In other embodiments, the energy saver 1' can also be manufactured into three groups of single-phase 220V reactive power compensation for three-phase 380V power users with inductive imbalance of three-phase AC or single-phase 220V power users with independent single-phase 220V reactive power compensation, such as air conditioning, refrigeration and other load circuits. As in the single-phase 220V power user, the above-mentioned capacitor group uses 220V single-phase capacitor. Other elements are the same as the first embodiment, and therefore will not be described in detail. In addition, when the output capacity of the reactive power compensation regulator is increased, and the load is a capacitive load, the shunt capacitor control contactor can be omitted, and the single-phase capacitor can be directly driven by the reactive power compensation regulator to work, which is suitable for home and commercial use.

[0044] When the output mode of the regulator 1 is changed to voltage or current signal, the thyristor, field effect transistor or power transistor is controlled respectively, and the AC contactor 2 and the movable contact 20 can be replaced by the thyristor, field effect transistor or power transistor.

[0045] Please refer to Figures 5-6 The application provides a kind of intelligent power grid efficient energy-saving system, including intelligent reactive power compensation regulator, shunt capacitor control switch, capacitor group and three-phase current transformer;The intelligent reactive power compensation regulator includes digital quantization monitoring module and intelligent operation control module, and the digital quantization monitoring module real-time acquisition power factor, active power, reactive power, operating state and fault information and send to the intelligent operation control module, so that the intelligent operation control module generates optimal output control combination instruction;The shunt capacitor control switch uses zero potential switch, and the zero potential switch is turned on or turned off when the potential difference at both ends is approximately zero;The three-phase current transformer includes A-phase current transformer, B-phase current transformer and C-phase current transformer, is respectively set on three-phase power supply main circuit, and corresponding secondary side is connected with the sampling current input end of intelligent reactive power compensation regulator corresponding;The capacitor group uses Y type connection design, and corresponding neutral point is effectively connected with power zero line;The intelligent reactive power compensation regulator controls the access or disconnection of capacitor group by sending the optimal output control combination instruction to the shunt capacitor control switch.

[0046] The system is based on the original scheme of intelligent reactive power automatic compensation energy saver architecture, and combines the digitalization, intelligentization, high-precision measurement and control and reliability improvement technology in the iteration scheme to form the following core components: (I) Intelligent reactive power compensation regulator (core control unit): Digital quantitative monitoring module is used to collect parameters in real time: power factor, operating power factor, active power, reactive power, active / reactive power, output combination state, device operating state and fault information (such as overload, capacitor fault, communication anomaly, etc.). Record the above parameters in time sequence (minimum interval 1 second), storage period ≥ 30 days, and support local query and remote transmission. Analyze the "health status" of the device through self-checking algorithm, such as when the capacitance attenuation exceeds 20%, trigger an alarm, and record the fault occurrence time, type and historical operation data for maintenance.

[0047] The intelligent operation control module calculates the reactive power demand of each phase based on real-time sampling of three-phase current and voltage signals, and generates the optimal capacitor switching combination (supports "sequential output", "intelligent control" and "binary combination switching") using fuzzy logic or dynamic programming algorithm, with a response time ≤ 20ms (one power frequency cycle). According to the calculation result, send wireless (Bluetooth, effective distance 100m) or wired control signal to the shunt capacitor control switch, support multi-channel parallel control (up to 10 output channels, can be expanded).

[0048] The shunt capacitor control switch (switching execution unit) is based on zero potential switch technology and uses special electronic switches that only conduct or turn off when the potential difference between the two ends is ≈0V (error ±5V), completely avoiding the arc impact and capacitor switching overvoltage (such as inrush current suppression rate ≥95%) when the traditional contactor breaks. Compared with traditional contactors (capacitor life 2 years), zero potential switch with new type capacitor group can extend the service life to 20 years, reduce maintenance cost. Support 380V / 220V input voltage, coil (or drive circuit) according to voltage type connection phase line or zero line, rated current ≥ 1.5 times the working current of capacitor group.

[0049] Capacitor group (reactive power compensation unit) adopts star (Y type) connection, three-phase capacitor neutral point is directly connected to power zero line (neutral line), shell is grounded, which improves system safety. Compared with traditional delta connection, the withstand voltage performance is improved by √3 times (380V system, single-phase withstand voltage from 380V to 220V x √3 ≈ 380V, actual design withstand voltage ≥ 450V), suitable for high-precision compensation scenarios.

[0050] The capacitance grading strategy includes: the first level (fine compensation): 6-way capacitance is increased by 2^(N-1) times (N=1-6), such as C1=10 μF, C2=20 μF, … C6=320 μF, supporting binary combination switching (total capacity covers 10-630 μF, step 10 μF). The second level (coarse compensation): 4-way capacitance is the same (C7-C10=640 μF, which is 2 times of C6), used for fast response to large reactive power demand scenarios. A single capacitor uses impact-resistant medium, built-in discharge resistor (voltage drops to below 50V within 5 minutes after power failure), supporting replaceable modular installation.

[0051] The three-phase current transformer (sampling unit) independently samples three phases, sets A-phase (La1 / La2), B-phase (Lb1 / Lb2), and C-phase (Lc1 / Lc2) current transformers, which are respectively sleeved on the three-phase power supply main line, and the primary current matches the maximum current of the main switch (such as N / 5A). The secondary side uniformly outputs a 5A standard signal to the regulator sampling end. The transformer accuracy is ≥0.5 level, and the phase error is ≤1°, solving the single-phase monitoring blind area problem when the three-phase load is unbalanced, and ensuring that the error of each phase reactive power calculation is ≤2%.

[0052] The protection and auxiliary module main switch uses an air switch, which has overall overload protection (rated current 1.2 times instantaneous tripping) and fault isolation function. Each capacitor bank branch is equipped with a branch air switch (Kr), with a nominal current of 1.5-2 times the branch rated current (such as 16A switch for 5kVar branch), supporting single or multi-path combined installation (≤5kVar branch can be multi-path shared switch).

[0053] The power-off protection contactor is connected to the external power supply (220V / 380V), which automatically cuts off the connection between the capacitor bank and the line when power is off, preventing residual charge from discharging externally and causing injury. The contact current is ≥1.5 times the total current.

[0054] The wireless communication module supports Bluetooth 5.0 (local configuration) and 4G / NB-IoT (remote), regularly (default 15 minutes) sends real-time operation data and fault alarm to the headquarters system, and supports OTA firmware upgrade.

[0055] The main circuit architecture includes: power supply line → user main switch (6) → user meter (7) → energy saver main switch (5) → three-phase current transformer (la / lb / lc) → branch capacitor control switch (zero potential switch) → capacitor bank (Y-type connection, neutral point connected to zero line) → load side.

[0056] The regulator wiring is connected to Ua / Ub / Uc (three-phase phase lines) and zero line through the voltage sampling end, and la2 / lb2 / lc2 (transformer secondary output) through the current sampling end, and the output control line communicates with the zero potential switch through the wireless module.

[0057] Capacitor bank installation through Y-type connection, the neutral point must be reliably connected to the zero line (cross-sectional area ≥ 50% of the phase line), and the shell is grounded (ground resistance ≤ 4Ω); the triangle connection is only reserved for compatible design, and Y-type is preferred. The distance between the capacitor bank and the switch is ≤ 30 cm, the line uses flame-retardant cable, and the voltage rating is ≥ 600V.

[0058] The regulator collects three-phase voltage and current signals every 20 ms (power frequency period), calculates the power factor of each phase (cosφA / cosφB / cosφC) and the total reactive power Q=Qa+Qb+Qc. Compared with the set target power factor (such as 0.95), if the current Q is greater than the set lower limit (such as Q>10kVar), the capacitor is triggered to be put into operation; if Q is less than the set upper limit (such as Q<-5kVar), the capacitor is triggered to be cut off.

[0059] The switching strategy execution includes: sequential output: according to the capacity from small to large, each road is switched, which is suitable for stable compensation scene. Intelligent control: according to the real-time Q value, the capacitor combination closest to the current demand is preferentially switched (such as Q=150kVar, C5+C6=80+160=240kVar is selected, and the redundant capacity is gradually cut off), which supports multiple capacitor groups in parallel switching (interval 50ms staggered delay, to avoid inrush current superposition). When a single road switch or capacitor fails, the system automatically skips the road and adjusts the compensation strategy, while sending fault codes to the maintenance end.

[0060] The zero potential switch action conditions include: on: detect the voltage across the switch ≤ 5V and last for 10ms, trigger the on command (avoid voltage zero point jitter). Off: detect the load current ≤ 10% rated value and voltage zero point 5ms before, turn off in advance to reduce arc.

[0061] Initial configuration through mobile phone APP scan code to enter each capacitor group capacity (supporting Bluetooth near field configuration), the regulator automatically generates the optimal switching table and stores it in EEPROM. Calibrate the phase of three-phase current transformer to ensure that Ua / la, Ub / lb, Uc / lc are one-to-one corresponding, avoid phase misconnection leading to compensation failure. Check the capacitor capacity every year (replace when the attenuation exceeds 10%), check the wear of the zero potential switch contact (replace when the on resistance > 100mΩ). Analyze historical data through remote platform to optimize compensation parameters (such as adjusting the switching threshold according to seasonal load changes).

[0062] Through the above design, the system realizes the upgrade from analog control to digital intelligent control, breaks through the performance bottleneck of traditional reactive power compensation equipment, and is suitable for three-phase 380V balanced / unbalanced load and single-phase 220V scene (such as home, business, industrial motor load), which significantly improves energy saving efficiency and grid compatibility.

[0063] In some embodiments, the system further comprises a wireless control module for realizing wireless signal transmission between the intelligent reactive power compensation regulator and the shunt capacitor control switch, and the intelligent reactive power compensation regulator sends optimal output control combination instructions to the shunt capacitor control switch through the wireless control module to control the access or disconnection of the capacitor bank.

[0064] By adding a wireless control module between the intelligent reactive power compensation regulator and the shunt capacitor control switch, wireless transmission of signals is realized, replacing the wired output control lines in the original scheme.

[0065] In the original scheme, the intelligent regulator is connected to the shunt capacitor control contactors (10 contactors in the embodiment) through 10 wired output control lines. In the present embodiment, a wireless control module (such as a Bluetooth module) is used, and the regulator sends "on / off" instructions to each shunt switch through wireless signals. The wireless control module supports bidirectional communication, and the regulator can monitor the state of the shunt switch in real time and send optimal output control combination instructions (such as controlling the access of a specific capacitor bank according to the reactive power calculation results). It is suitable for scenarios where the capacitor bank layout is scattered or the wiring is complex, reduces cable layout, and improves system flexibility.

[0066] In some embodiments, the wireless control module uses Bluetooth wireless transmission technology, with an effective transmission distance of 100 meters, for entering the capacitance parameters of the capacitor bank by scanning the code, realizing wireless signal transmission and parameter configuration between the intelligent reactive power compensation regulator and the shunt capacitor control switch.

[0067] By using Bluetooth wireless transmission technology (effective distance 100 meters), the scanning code input is supported to enter the capacitance parameters of the capacitor bank, realizing wireless signal transmission and parameter configuration.

[0068] The Bluetooth module is integrated in the intelligent regulator and the shunt zero-potential switch (or the original shunt capacitor control contactor) with a built-in Bluetooth communication module, supporting IEEE 802.15.1 protocol, with a signal coverage range of up to 100 meters. The parameter entry method scans the code (such as a two-dimensional code label, marked with the capacitance of each capacitor bank C1-C10) through a mobile phone or a special device, and transmits the capacitance parameters wirelessly to the regulator, replacing manual input or program preset in the original scheme, reducing human configuration errors. The control instructions generated by the regulator (such as "turn on C3 and C5 capacitor banks") are sent to the corresponding switch after being encoded by Bluetooth, and the switch executes the action and feeds back the state signal after receiving the instructions.

[0069] In some embodiments, the system further includes a main switch and a branch line protection switch; the main switch is an air switch used for overall overload protection and temporary isolation; the branch line protection switch is an air switch with a nominal current of 1.5 to 2 times the rated current of the corresponding branch line, installed in front of the corresponding branch capacitor control switch, and the branch line protection switch is installed individually or in combination for branch lines with a voltage of less than 5 kVvar.

[0070] By adding branch line protection switches, a hierarchical protection system is formed with the main switch, thereby improving system safety.

[0071] The main switch (air switch) adopts the main switch 5 in the original scheme, which is located inside the energy saver to realize overall overload protection (such as tripping when the current exceeds the rated value) and temporary isolation (for easy maintenance).

[0072] Branch line protection switches use air circuit breakers with a nominal current of 1.5-2 times the rated current of the corresponding branch line (e.g., if the rated current of the branch line is 10A, then a 16A or 20A switch is selected), installed upstream of the branch capacitor control switch (e.g., a zero-potential switch). For branch lines less than 5 kvar, a separate protection switch can be installed (one switch corresponds to one capacitor bank); or multiple circuits can be combined (e.g., three capacitor banks ≤ 5 kvar can use one protection switch, with the total current not exceeding the switch's rated value). When an overcurrent or short circuit occurs in a branch line, the corresponding protection switch will trip first, without affecting the operation of other branches, thus minimizing the scope of the fault's impact.

[0073] In some embodiments, the reparameterization of the measurement data of traditional transmission and reception positions into midpoint position and offset position parameters includes: the digital quantization monitoring module records and stores the recording time, power factor, operating power factor, active power, reactive power, active energy, reactive energy, output combination, operating status and fault information in real time, and obtains the corresponding emergency response information by sending the fault information to a preset emergency response terminal.

[0074] The digital quantitative monitoring module records key parameters in real time and sends fault information to the emergency response terminal.

[0075] Monitoring parameters include: real-time recording of time, power factor, operating power factor, active power (kW), reactive power (kVar), active energy (kWh), reactive energy (kVarh), output combination (e.g., the currently connected capacitor bank number), operating status (normal / alarm / fault), and fault information (e.g., "C7 capacitor bank overvoltage"). The monitoring module stores data in the regulator's built-in memory (e.g., EEPROM) and periodically (e.g., every 15 minutes) via wireless or wired means. When an anomaly is detected (e.g., capacitor bank overheating), fault information is immediately sent to the after-sales service department and maintenance team via SMS, APP push, etc., along with the fault occurrence time, location (e.g., branch number), and preliminary diagnostic results for rapid response.

[0076] In some embodiments, when the zero-potential switch is turned on or off, it ensures that the potential difference across the switch is approximately zero, thereby avoiding impact fluctuations on the capacitor bank, switch assembly, peripheral connected equipment, and power grid.

[0077] By using a zero-potential switch as the shunt capacitor control switch, the circuit is turned on / off when the potential difference is approximately zero, thus avoiding inrush current.

[0078] The switching characteristics are achieved through the built-in voltage detection circuit of the zero-potential switch, which triggers the conduction or cut-off action only when the voltage difference across the switch is ≤1V (approximately zero potential), unlike traditional AC contactors (which are prone to arcing when disconnected under energized conditions).

[0079] To eliminate inrush current, the voltage across the capacitor bank is made consistent with the grid voltage when the circuit is on, preventing inrush current during switching. When switching off, the capacitor is allowed to discharge to near zero potential before disconnecting, preventing back EMF surges. Under traditional contactor control, the average lifespan of a capacitor is 2 years; with zero-potential switching, this can be increased to 20 years (due to the absence of current surges causing plate aging). The switch coil (or drive circuit) supports 380V or 220V, is compatible with the original design, and the contact current is ≥ 1.5 times the capacitor bank's operating current.

[0080] In some embodiments, the capacitor bank adopts a novel capacitor design and a Y-type connection, with the neutral point effectively connected to the power supply neutral line. During commissioning and maintenance, a detection mechanism is used to avoid the capacitor bank becoming energized and potential safety hazards to the neutral line.

[0081] By using a new type of capacitor bank with a Y-type connection, the neutral point is connected to the power supply neutral line, improving safety and withstand voltage performance.

[0082] The Y-type structure uses three single-phase capacitors (or three-phase capacitors) with one end connected to phase lines A, B, and C respectively, and the other end connected to the neutral point. The neutral point is reliably connected to the power supply neutral line (N line) via a conductor, unlike the original delta connection (which has no neutral point). The rated voltage of the single-phase capacitor is 220V (220V phase voltage in Y-type connection), which is simpler to design and safer than the 380V phase voltage (380V line voltage) of the delta connection (the theoretical withstand voltage multiple is √3, i.e., 220V phase voltage in Y-type in a 380V system, reducing insulation requirements). During commissioning and maintenance, the main switch should be disconnected first, and the residual charge of the capacitor bank should be discharged through the discharge resistor. Operation should only proceed after the neutral point voltage is confirmed to be zero to avoid the risk of live work.

[0083] In some embodiments, the three-phase current transformer includes an A-phase current transformer, a B-phase current transformer, and a C-phase current transformer, which are respectively mounted on the A-phase line, B-phase line, and C-phase line of the three-phase power supply main circuit. The corresponding secondary output terminals are respectively connected to the sampling current input terminals of the intelligent reactive power compensation regulator. The primary current of the three-phase current transformer matches the current of the main circuit, and the maximum secondary current is 5 amps.

[0084] By adding three current transformers (A / B / C phases) to monitor the three-phase current separately, the compensation accuracy of three-phase unbalanced loads is improved.

[0085] The current transformer configuration includes: Model: N / 5A specification (N is the maximum current value of the main switch), with the primary side connected to the A / B / C phase power lines respectively, and the secondary side output terminals (La1 / La2, Lb1 / Lb2, Lc1 / Lc2) connected to the three-phase sampling input terminals of the regulator. Wiring requirements: The A / B / C phase current transformers must have strict phase correspondence with the voltage input terminals (Ua / Ub / Uc) of the regulator to ensure accurate three-phase power calculation (e.g., the A-phase current transformer corresponds to the A-phase voltage sampling). For three-phase load imbalance scenarios (e.g., single-phase air conditioning clusters), the regulator can calculate the reactive power of each phase separately and independently control the connection of the capacitor bank of the corresponding phase, avoiding compensation deviations caused by traditional single-phase monitoring.

[0086] In some embodiments, after generating the optimal output control combination instruction, the intelligent computing control module performs a self-check analysis on the system operating status after implementing the instruction, diagnoses the health status of the device itself, automatically issues an alarm message when an abnormality is detected, and saves the valid parameters in the corresponding device database.

[0087] After generating control commands, the intelligent computing control module performs a self-check of the system status, diagnoses the health status of the equipment, and issues an alarm.

[0088] The self-inspection process includes: Verification after command execution: After sending the "Connect C2 capacitor bank" command, the current in the branch is checked using a current transformer to see if it meets expectations (e.g., C2 rated current 10A, allowable ±5% deviation). If the deviation exceeds 10%, it is marked as abnormal. Health diagnosis: Regularly (e.g., hourly) check the number of operation cycles of each branch switch, capacitor bank temperature (using built-in temperature sensors), and transformer signal stability. If the number of switch operation cycles exceeds the lifespan threshold (e.g., 100,000 cycles) or the temperature exceeds 80℃, an alarm is triggered. Data storage and feedback: Abnormal information and handling records (e.g., protection switch tripping after an overcurrent incident, manual reset time) are stored in the equipment database for subsequent maintenance and optimization reference, and simultaneously uploaded to the headquarters system for big data analysis.

[0089] In some embodiments, the intelligent operation control module supports a sequential output mode or an intelligent control output mode. The sequential output mode connects or disconnects capacitors one by one in order of increasing capacitance value. The intelligent control output mode compares the actual measured reactive power and reactive current values ​​with the preset capacitance values ​​of each channel in descending order, and then selects to connect or disconnect them one by one, or combines and outputs them after binary value processing and staggered delay. The capacitance values ​​are preset by the program, manually input, or measured by a self-test program and stored in a preset memory.

[0090] By supporting both "sequential output" and "intelligent control" modes, the capacitance value can be preset in multiple ways.

[0091] The sequential output mode connects or disconnects capacitors one by one according to their capacitance values ​​from smallest to largest (e.g., C1 < C2 < ... < C6, C7-C10 have the same capacitance value and are greater than C6). This mode is suitable for scenarios where the reactive power demand of the load changes gradually (e.g., during the motor startup process).

[0092] The intelligent control mode includes: Capacity comparison: Based on the real-time measured reactive current value, the capacitor bank is selected from largest to smallest (e.g., if 50kVar compensation is needed, C10 (assuming C10=32kVar) + C6 (16kVar) is connected first, and the remaining 2kVar is made up by C1 (2kVar)), reducing the number of switching operations. Binary processing: The capacitor bank values ​​are encoded in a 2^(N-1) gradient (e.g., C1=1, C2=2, C3=4…), and accurate compensation is achieved through binary combinations (e.g., 1010 corresponds to C2+C4). Offset delay (e.g., 50ms switching interval per channel) avoids current surges caused by simultaneous operation. Capacitance configuration: Preset / input: The capacitance value of each capacitor bank can be manually input via the buttons on the regulator panel, or the standard value can be preset at the factory (e.g., C1=2kVar, C2=4kVar). Self-testing: The regulator automatically connects the capacitor bank one by one, measures the current change after connection, calculates the actual capacitance value and stores it (to adapt to parameter drift after capacitor aging).

[0093] This application utilizes a digital quantitative monitoring module to collect parameters such as power factor and active / reactive power in real time. Combined with an intelligent computing control module, it generates the optimal compensation strategy, significantly improving reactive power compensation accuracy and resolving the lag and error issues of traditional analog control. By employing zero-potential switches for the shunt capacitor control switches, the system conducts / turns off when the potential difference is approximately zero, completely avoiding inrush current during switching operations. This extends the average lifespan of the capacitor bank from 2 years in traditional solutions to 20 years, while also reducing interference to the power grid and electronic equipment. Independent sampling by A / B / C three-phase current transformers accurately addresses three-phase load imbalance scenarios, enhancing the targeting of the compensation strategy and resolving the uneven compensation problem caused by traditional single-phase monitoring. The capacitor bank uses a Y-connection with neutral grounding, improving withstand voltage performance and safety reliability. Combined with zero-potential switches and an intelligent control module, it achieves shock-free switching, reducing equipment failure risks. By recording operating status, fault information, and other parameters in real time and sending them to the headquarters system, it supports remote monitoring and fault diagnosis, improving operation and maintenance efficiency and the level of intelligent equipment management.

[0094] It should be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the application. It should be understood that when an element or layer is referred to as “on,” “adjacent to,” “connected to,” or “coupled to” other elements or layers, it may be directly on, adjacent to, connected to, or coupled to other elements or layers, or there may be intervening elements or layers. Conversely, when an element is referred to as “directly on,” “directly adjacent to,” “directly connected to,” or “directly coupled to” other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc., may be used to describe various elements, components, areas, layers, and / or portions, these elements, components, areas, layers, and / or portions should not be limited by these terms. These terms are merely used to distinguish one element, component, area, layer, or portion from another element, component, area, layer, or portion. Therefore, without departing from the teachings of this application, the first element, component, area, layer, or portion discussed below may be referred to as a second element, component, area, layer, or portion.

[0095] Spatial relation terms such as “below,” “under,” “below,” “under,” “above,” “above,” etc., are used herein for convenience of description to describe the relationship between one element or feature shown in the figure and other elements or features. It should be understood that, in addition to the orientation shown in the figure, spatial relation terms are intended to also include different orientations of the device in use and operation. For example, if the device in the figure is flipped, then the element or feature described as “below,” “under,” or “below” other elements or features will be oriented “above” other elements or features. Therefore, the exemplary terms “below” and “under” can include both above and below orientations. The device may be otherwise oriented (rotated 90 degrees or otherwise) and the spatial descriptive terms used herein will be interpreted accordingly.

[0096] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. When used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising” and / or “including,” when used in this specification, identify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups. When used herein, the term “and / or” includes any and all combinations of the associated listed items.

[0097] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0098] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A smart grid high-efficiency energy-saving system, characterized in that, This includes intelligent reactive power compensation regulators, shunt capacitor control switches, capacitor banks, and three-phase current transformers. The intelligent reactive power compensation regulator includes a digital quantization monitoring module and an intelligent operation and control module. The digital quantization monitoring module collects power factor, active power, reactive power, operating status and fault information in real time and sends them to the intelligent operation and control module so that the intelligent operation and control module can generate the optimal output control combination command. The shunt capacitor control switch is a zero-potential switch, which is turned on or off when the potential difference between its two ends is approximately zero; the three-phase current transformer includes an A-phase current transformer, a B-phase current transformer, and a C-phase current transformer, which are respectively mounted on the three-phase power supply main circuit, and the corresponding secondary sides are respectively connected to the sampling current input terminal of the intelligent reactive power compensation regulator; the capacitor bank adopts a Y-type connection design, and the corresponding neutral point is effectively connected to the power supply neutral line. The intelligent reactive power compensation regulator controls the connection or disconnection of the capacitor bank by sending the optimal output control combination command to the branch capacitor control switch.

2. The method according to claim 1, characterized in that, The system also includes: The wireless control module is used to realize wireless signal transmission between the intelligent reactive power compensation regulator and the shunt capacitor control switch. The intelligent reactive power compensation regulator sends the optimal output control combination command to the shunt capacitor control switch through the wireless control module to control the connection or disconnection of the capacitor bank.

3. The system according to claim 2, characterized in that, The wireless control module uses Bluetooth wireless transmission technology with an effective transmission distance of 100 meters. It is used to input the capacitance parameters of the capacitor bank by scanning a code, thereby realizing wireless signal transmission and parameter configuration between the intelligent reactive power compensation regulator and the branch capacitor control switch.

4. The system according to claim 1, characterized in that, The system also includes a main switch and branch line protection switches; The main switch is an air switch, used for overall overload protection and temporary isolation; The branch line protection switch is an air switch with a nominal current of 1.5 to 2 times the rated current of the corresponding branch line. It is installed in front of the corresponding branch capacitor control switch. The branch line protection switch can be installed individually or in combination for branch lines with a current of less than 5 kVvar.

5. The system according to claim 1, characterized in that, The process of reparameterizing the measurement data of traditional transmit and receive positions into midpoint and offset position parameters includes: The digital quantitative monitoring module records and stores in real time the recording time, power factor, operating power factor, active power, reactive power, active energy, reactive energy, output combination, operating status and fault information. By sending the fault information to the preset emergency response terminal, the corresponding emergency response information is obtained.

6. The system according to claim 1, characterized in that, When the zero-potential switch is turned on or off, it ensures that the potential difference between the two ends of the switch is approximately zero, thus avoiding impact fluctuations on the capacitor bank, switch assembly, peripheral connected equipment, and power grid.

7. The system according to claim 1, characterized in that, The capacitor bank adopts a novel capacitor design and uses a Y-type connection method, with the neutral point effectively connected to the power supply neutral line. During debugging and maintenance, a detection mechanism is used to avoid the capacitor bank becoming energized and potential safety hazards to the neutral line.

8. The system according to claim 1, characterized in that, The three-phase current transformer includes an A-phase current transformer, a B-phase current transformer, and a C-phase current transformer, which are respectively installed on the A-phase line, B-phase line, and C-phase line of the three-phase power supply main circuit. The corresponding secondary output terminals are respectively connected to the sampling current input terminals of the intelligent reactive power compensation regulator. The primary current of the three-phase current transformer matches the current of the main circuit, and the maximum secondary current is 5 amps.

9. The system according to claim 1, characterized in that, After generating the optimal output control combination command, the intelligent computing control module performs a self-check analysis on the system operation status after implementing the command, diagnoses the health status of the equipment itself, automatically issues an alarm message when an abnormality is detected, and saves the valid parameters in the corresponding equipment database.

10. The system according to claim 1, characterized in that, The intelligent operation control module supports sequential output mode or intelligent control output mode. The sequential output mode is to connect or disconnect the capacitors one by one in order of their capacitance values ​​from smallest to largest. The intelligent control output mode compares the actual measured reactive power and reactive current values ​​with the preset values ​​of each capacitor from largest to smallest, and then selects to connect or disconnect them one by one, or combines them for output after binary numerical processing and staggered delay. The capacitor values ​​are measured and stored in a preset memory through program preset, manual input or self-test program.

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