Intelligent control system of electromagnetic balance power saver

Abstract

The invention provides an intelligent control system for an electromagnetic balance power saver, and relates to the technical field of electric power energy saving, and the system comprises a data collection module which is used for collecting voltage and current instantaneous values of an input end and an output end of the power saver; the load feature recognition module is used for extracting a load feature vector; determining a current load type; the self-adaptive voltage regulation decision module is used for selecting a corresponding voltage regulation gain coefficient according to the current load type and calculating a continuous voltage regulation amount through a nonlinear coupling algorithm; the gear execution and feedback module is used for mapping the continuous voltage adjustment amount into a discrete gear switching instruction and controlling the power saver to be switched to a target gear; evaluating the change of the load feature vector after voltage regulation; and the health monitoring module is used for monitoring the iron core temperature, the gear switching frequency and the insulation resistance to ground of the main loop of the power saver, and performing early warning when the monitored parameters exceed a preset threshold value. The technical problem that a fixed voltage regulation strategy cannot adapt to load difference and dynamics can be solved.

Description

Technical Field

[0001] This invention relates to the field of power energy conservation technology, and in particular to an intelligent control system for an electromagnetic balance energy-saving device. Background Technology

[0002] Electromagnetic balance energy-saving devices reduce line losses and equipment copper losses by lowering the load-side voltage, thereby achieving energy savings. Traditional energy-saving devices employ a fixed voltage regulation strategy based on voltage deviation; that is, when the input voltage is detected to be higher than the rated value by a certain margin, the voltage is reduced according to a preset fixed level. The core technical problem with this control method is that different types of loads have fundamentally different response characteristics to voltage adjustment. For inductive loads such as motors, the increased slip when the voltage is reduced leads to an increase in stator current, resulting in a decrease in the power factor and an increase in reactive power losses that may offset the active power saving effect. For resistive loads such as lighting, the power is proportional to the square of the voltage, and the voltage reduction energy saving effect is significant and linearly predictable. Nonlinear loads, including frequency converters or switching power supplies, have a wide voltage input range and constant power output characteristics, and their actual power consumption is not sensitive to voltage changes. Excessive voltage reduction not only fails to save energy but may also reduce efficiency due to increased input stage losses. Using a uniform fixed voltage regulation strategy cannot adapt to the differences in load characteristics. For some loads, excessive voltage reduction leads to a decrease in system efficiency, while for other loads, insufficient voltage reduction fails to fully realize the energy-saving potential. More importantly, in practical applications, the load is not constant. The same line may be connected to different combinations of equipment at different times, and the impedance characteristics and power factor of the load are in dynamic change. Fixed strategies cannot track such changes and make real-time optimization adjustments.

[0003] Chinese patent CN202340122U discloses a phase-shifting electromagnetic balance voltage regulation energy-saving device. This device utilizes three columns on the same iron core to achieve phase shifting, compensation, energy storage, and voltage regulation functions. It achieves phase shifting adjustment of three-phase balance, suppression of surges and harmonics, reduction of zero-sequence current, electromagnetic compensation, and improvement of the power factor through three-phase coils wound in a Z-shape on the iron core. This patent adjusts excess voltage by changing the number of winding groups of the three-phase coils to achieve multi-level voltage regulation. It uses an electronic switch array or AC contactor to control the connection of different taps to the neutral line to achieve level switching. This technical solution mainly focuses on achieving electromagnetic balance and multi-level voltage regulation through transformer structure design; however, its level switching strategy still relies on preset fixed control logic, lacking dynamic identification of load characteristics and an adaptive voltage regulation decision mechanism. It cannot optimize the voltage regulation strategy based on real-time changes in load impedance characteristics to achieve optimal energy-saving effects. Summary of the Invention

[0004] In view of this, the present invention provides an intelligent control system for an electromagnetic balance energy-saving device. By constructing voltage and current phase trajectories to extract multi-dimensional load feature vectors to accurately identify the dynamic impedance characteristics of the load, adaptive voltage regulation decision is achieved based on energy transfer efficiency gradient and nonlinear coupling algorithm, and control parameters are continuously optimized through a closed-loop feedback mechanism. At the same time, the device health monitoring function is integrated, thereby maximizing the energy-saving effect and ensuring reliable operation of the device throughout its entire life cycle under different load conditions.

[0005] The technical solution of this invention is implemented as follows: This invention provides an intelligent control system for an electromagnetic balance energy-saving device, comprising: The data acquisition module is used to collect the instantaneous voltage and current values ​​at the input and output terminals of the energy-saving device; The load feature identification module is used to construct a voltage-current phase trajectory based on the instantaneous values ​​of voltage and current, and extract the area ratio coefficient, phase offset index and waveform distortion index of the phase trajectory as load feature vectors to characterize the load impedance characteristics; the real-time acquired load feature vectors are matched with a preset standard load feature library to determine the current load type; The adaptive voltage regulation decision module is used to select the corresponding voltage regulation gain coefficient according to the current load type, and apply a test voltage disturbance to the output terminal of the energy saver to detect the gradient of energy transfer efficiency with respect to voltage; based on the efficiency gradient, the voltage regulation gain coefficient, and the deviation between the current efficiency and the reference efficiency, the continuous voltage adjustment is calculated through a nonlinear coupling algorithm. The gear execution and feedback module is used to map the continuous voltage adjustment amount into discrete gear switching commands to control the energy saver to switch to the target gear. After voltage regulation, the change of the load characteristic vector is evaluated. If the change exceeds the threshold, the load characteristic identification module is triggered to re-identify the load type and adaptively correct the voltage regulation gain coefficient according to the degree of agreement between the actual voltage regulation effect and the expected effect. The health monitoring module is used to monitor the core temperature, gear switching frequency, and insulation resistance to ground of the energy-saving device, and to issue an early warning when the monitored parameters exceed the preset threshold.

[0006] Preferably, the sampling frequency of the data acquisition module is set to 128 times the power frequency, and 128 instantaneous voltage and current data points are collected in each power frequency cycle. The data acquisition module is also used to measure the active power at the input end and the active power at the output end of the energy-saving device. The power measurement adopts the digital sampling method, which is obtained by numerical integration of the product of the instantaneous voltage and current values ​​in one power frequency cycle.

[0007] Preferably, the area proportion coefficient Defined as the closed envelope area of ​​the phase trajectory With peak voltage and peak current The ratio of the areas that make up the rectangle is calculated using the following formula: The closed envelope area of ​​the phase trajectory The calculation is performed using the trapezoidal integral method, i.e. , and These are the instantaneous values ​​of voltage and current at the nth sampling point; Phase offset index Defined as the normalized value of the inverse cosine of the power factor, the calculation formula is: in Power factor; Waveform distortion index Defined as the ratio of the root mean square value of the RMS value of the 2nd to 13th harmonic currents to the RMS value of the fundamental current, the calculation formula is: in The effective value of the h-th harmonic current is obtained through Fast Fourier Transform. This is the effective value of the fundamental current. The highest harmonic order is considered.

[0008] Preferably, the method for matching the real-time acquired load feature vector with a preset standard load feature library is as follows: Calculate the real-time load feature vector The weighted Euclidean distance between the load and each standard load feature vector in the standard load feature library is calculated using the following formula: Where the subscript t represents the current time, Let j be the feature vector of the j-th standard load. We select weighted Euclidean distance as the weighting coefficient. The smallest standard load type is used as the current load type k; The load state membership degree corresponding to the minimum weighted Euclidean distance is calculated using a Gaussian membership function. The calculation formula is as follows: in The minimum weighted Euclidean distance. The width parameter of the membership function. This represents the membership degree of the load state.

[0009] Preferably, the method of applying a test voltage disturbance to the output terminal of the energy-saving device to detect the gradient of energy transfer efficiency with respect to voltage is as follows: At the current output voltage Apply amplitude on the basis The test voltage disturbance, of which At rated voltage, maintain the disturbance for 3 power frequency cycles, and measure the efficiency before the disturbance. and efficiency after perturbation Calculate the change in efficiency ,in Indicates the time interval for the duration of the disturbance; The gradient of energy transfer efficiency with respect to voltage is calculated using a numerical differential method. The calculation formula is as follows: ; Before applying a test voltage disturbance, detect the load power fluctuation rate. When the power fluctuation rate exceeds a preset threshold, pause gradient detection and keep the current level unchanged.

[0010] Preferably, the calculation formula for the nonlinear coupling algorithm is as follows: In the formula, This is a continuous voltage adjustment amount. This is the voltage regulation gain coefficient. Let be the sign function of the efficiency gradient. The gradient of energy transfer efficiency with respect to voltage. It is a non-linear exponent. For efficiency reference, The energy transfer efficiency at the current time t; Among them, the nonlinear index Based on load status membership Dynamic adjustment, the calculation formula is: Reference efficiency Set as the highest efficiency value recorded during historical operation. 98% of .

[0011] Preferably, the method for mapping continuous voltage adjustment amounts to discrete gear switching commands is as follows: According to the continuous voltage adjustment amount Voltage difference between adjacent gears The gear shift change is calculated using the following formula: in This is the rounding function. This refers to the change in gear position. Current gear With gear change Add them together to get the target gear. Limit the target gear to keep it within the effective gear range. With the current gear The gear shifting action is not performed simultaneously.

[0012] Preferably, evaluating the change in the load eigenvector after voltage regulation includes: Calculate the load eigenvector before voltage regulation With the load characteristic vector after voltage regulation The Euclidean distance is used as the phase trajectory offset, and the calculation formula is: When phase trajectory offset Exceeding the preset offset threshold The load characteristic identification module is triggered to re-identify the load type. The voltage regulation gain coefficient is adaptively adjusted based on the degree of agreement between the actual voltage regulation effect and the expected effect, including: Calculate the evaluation coefficient for voltage regulation effect: in This refers to the efficiency after voltage regulation. Efficiency before voltage regulation. To measure the efficiency change during test disturbances, the voltage regulation effect evaluation coefficient is... When the voltage regulation gain coefficient is lower than the preset value, an adaptive correction is performed. The correction formula is as follows: in, This is the voltage regulation gain coefficient before correction. This is the corrected voltage regulation gain coefficient.

[0013] Preferably, the parameters monitored by the health monitoring module include: Energy-saving device main transformer core temperature When the core temperature exceeds the warning threshold A warning will be issued when the alarm threshold is exceeded. The power-saving device will automatically switch to bypass direct mode. Number of gear shifts Based on the cumulative number of switches Number of switching cycles with rated life The ratio is used to calculate the contactor life consumption rate. When the lifespan consumption rate exceeds a preset threshold, a warning or alarm will be issued; Main circuit insulation resistance to ground When the insulation resistance is lower than the qualified threshold An alarm will be issued at any time.

[0014] Preferably, the standard load characteristic library includes standard characteristic vectors for five typical load types: purely resistive load, high power factor inductive load, low power factor inductive load, capacitive load, and nonlinear load; voltage regulation gain coefficient. The gain coefficient value is determined based on the load type; different load types correspond to different gain coefficient values. The energy-saving device is designed with multiple output voltage levels, and the voltage difference between adjacent levels is... It is 3% of the rated voltage; the voltage regulation decision cycle is set to 10 seconds, and each cycle executes a complete process of feature recognition, gradient testing, voltage regulation decision, gear execution and effect evaluation.

[0015] The present invention has the following advantages over the prior art: This invention achieves a breakthrough in comprehensively characterizing load impedance characteristics from a single power factor parameter to multiple dimensions by constructing voltage and current phase trajectories and extracting three-dimensional feature vectors of area ratio coefficient, phase offset index, and waveform distortion index. It can effectively distinguish different load types such as purely resistive, inductive, capacitive, and nonlinear loads. The system uses test voltage perturbation to detect the gradient of energy transfer efficiency with respect to voltage, and calculates the continuous voltage adjustment through a dual nonlinear coupling algorithm that includes a gradient nonlinear exponential term and an efficiency deviation square root term. This achieves adaptive variation of the voltage adjustment amplitude with load characteristics and optimization process, ensuring rapid convergence when far from the optimum and avoiding oscillation when close to the optimum. By establishing a mapping mechanism from continuous voltage regulation to discrete gear selection, and evaluating the load characteristic offset and voltage regulation effect evaluation coefficient after gear switching to trigger load type re-identification and gain coefficient adaptive correction, a complete closed-loop feedback control loop is formed, enabling the system to continuously track load changes and optimize control strategies. The integrated core temperature monitoring, contactor life assessment and insulation resistance detection functions enable real-time perception and early warning of equipment health status, improving the reliability of the equipment throughout its entire life cycle. This invention fundamentally solves the technical problem that fixed voltage regulation strategies cannot adapt to load differences and dynamics, ensuring energy saving while also taking into account control stability and equipment reliability. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, 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 a system framework diagram of the present invention; Figure 2 This is a flowchart illustrating the adaptive voltage regulation decision-making and execution process of the present invention. Figure 3 This is a flowchart of the voltage regulation effect evaluation and parameter correction of the present invention. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0019] like Figure 1 As shown, this invention provides an intelligent control system for an electromagnetic balance energy saver, comprising: a data acquisition module for acquiring instantaneous voltage and current values ​​at the input and output terminals of the energy saver; a load feature identification module for constructing a voltage-current phase trajectory based on the instantaneous voltage and current values, and extracting the area ratio coefficient, phase offset index, and waveform distortion index of the phase trajectory as load feature vectors to characterize the load impedance characteristics, matching the real-time acquired load feature vectors with a preset standard load feature library to determine the current load type; and an adaptive voltage regulation decision module for selecting the corresponding voltage regulation gain coefficient according to the current load type, and applying a test voltage disturbance to the output terminal of the energy saver to detect energy transfer. The efficiency-voltage gradient is calculated using a nonlinear coupling algorithm based on the efficiency gradient, voltage regulation gain coefficient, and the deviation between the current efficiency and the reference efficiency. The gear execution and feedback module maps the continuous voltage regulation to discrete gear switching commands, controls the energy saver to switch to the target gear, evaluates the change in the load characteristic vector after voltage regulation, and if the change exceeds a threshold, triggers the load characteristic identification module to re-identify the load type and adaptively corrects the voltage regulation gain coefficient according to the degree of agreement between the actual voltage regulation effect and the expected effect. The health monitoring module monitors the core temperature of the energy saver, the number of gear switching times, and the insulation resistance of the main circuit to ground, and issues an early warning when the monitored parameters exceed preset thresholds.

[0020] In one embodiment of the present invention, the data acquisition module includes a voltage sensor and a current sensor disposed at the input and output terminals of the energy-saving device, for synchronously acquiring the instantaneous values ​​of the three-phase voltage. , , and instantaneous values ​​of three-phase current , , ,in and The instantaneous value is expressed in functional form and changes continuously with time. The sampling frequency is set to ,in The power frequency, that is, the frequency in each power frequency cycle. 128 instantaneous voltage and current data points were collected internally. The collected data points were represented using discrete subscripts. and ; The purpose of using a high sampling rate is to accurately capture the detailed features of voltage and current waveforms. In particular, for nonlinear loads containing high-order harmonics, a sufficient number of sampling points are needed to extract harmonic components through fast Fourier transform. The instantaneous data collected is analyzed on a single-phase basis. The three phases are processed independently and then a comprehensive judgment result is taken. When the load identification results of at least two of the three phases are the same, the identification result is adopted. If the identification results of the three phases are completely different, a conservative voltage regulation strategy is adopted. The data acquisition module also includes a power measurement unit, which calculates the active power at the input of the energy-saving device in real time. and output active power Power measurement uses digital sampling method, and the calculation formula is as follows: Where T is the power frequency period. This is the instantaneous voltage value. The instantaneous current value is obtained by numerically integrating the product of the instantaneous voltage and current values ​​over one power frequency cycle. The numerical integration is achieved using the trapezoidal integration method. ; To achieve full lifecycle health management of the equipment, the data acquisition module also integrates a group of equipment condition monitoring sensors, including temperature sensors installed on the surface of the main transformer core for monitoring the core temperature. An action counter installed in the contactor control circuit is used to accumulate the number of gear shifts. The online insulation resistance monitoring unit periodically measures the insulation resistance of the main circuit to ground. Insulation resistance is measured once a day during periods of light load to minimize disruption to the power supply. All collected data is transmitted to the central processing unit for further processing via an internal CAN bus or RS485 bus.

[0021] In one embodiment of the present invention, the load feature identification module constructs a voltage-current phase trajectory and extracts feature vectors based on the instantaneous voltage and current values ​​provided by the data acquisition module. Taking a single phase as an example, 128 voltage sampling points are obtained within a complete power frequency cycle. and the corresponding 128 current sampling points Using voltage as the x-axis and current as the y-axis, 128 coordinate points are plotted on a two-dimensional plane. The samples are connected sequentially to form a closed phase trajectory curve, where the subscript n represents the sampling point number; For purely resistive loads, since the voltage and current are strictly in phase and their ratio is constant, the phase trajectory degenerates into a straight line passing through the origin. For linear or capacitive loads, since the current and voltage have a fixed phase difference, the phase trajectory exhibits a standard elliptical shape, and the flattening of the ellipse reflects the power factor. For nonlinear loads, because the current waveform contains high-order harmonic components, the phase trajectory deviates from the standard elliptical shape, exhibiting distortion characteristics such as concave, convex, or distorted features. The load feature recognition module defines three phase trajectory morphology feature parameters to form a load feature vector. The first feature parameter is the area proportion coefficient. Defined as the closed envelope area of ​​the phase trajectory. With peak voltage and peak current The ratio of the areas that make up the rectangle is calculated using the following formula: The closed envelope area of ​​the phase trajectory The calculation is performed using the trapezoidal integral method, i.e.: and The instantaneous values ​​of voltage and current at the nth sampling point, with peak voltage. Peak current Area ratio coefficient The physical meaning of is the fullness of the phase trajectory, for a purely resistive load. The value is approximately 0.5, for linear or capacitive loads. The value increases as the power factor decreases, approaching 0.8, for nonlinear loads. The value typically fluctuates between 0.6 and 0.9; The second characteristic parameter is the phase shift index. The power factor is defined as the normalized inverse cosine value, and the calculation formula is: Where PF is the power factor, according to Calculate, where P is the active power. and These are the effective values ​​of voltage and current, respectively. The effective values ​​are obtained through... calculate, That is, the impedance angle, divided by Normalization The range of values ​​is Purely resistive load Purely inductive or purely capacitive loads ; The third characteristic parameter is the waveform distortion index. The effective value of the fundamental current is defined as the ratio of the root mean square value of the effective values ​​of the 2nd to 13th harmonic currents to the effective value of the fundamental current. The calculation formula is as follows: in The effective value of the h-th harmonic current is obtained by performing a fast Fourier transform on the sampled data. The fundamental current RMS value is given, and H=13 represents the highest harmonic order considered for a linear load. A value less than 0.05 indicates a nonlinear load. The value is usually greater than 0.2; Through the above three feature parameters The combination of features constitutes a three-dimensional feature vector Where the subscript t represents the current time, and as mentioned above, represents the instantaneous value function. , different, The parameter with subscript t represents the characteristic parameter value calculated at the current specific moment, which fully characterizes the impedance characteristics of the load in the characteristic space; The load feature identification module establishes a standard load feature library during the system initialization phase. It collects phase trajectory feature data for five typical loads through offline experiments, and calibrates the standard state point coordinates in the feature space for five types of loads: purely resistive load, high power factor inductive load, low power factor inductive load, capacitive load, and nonlinear load. , , , , The values ​​above are reference values ​​for a specific embodiment; the actual calibration values ​​will vary slightly depending on the specific load samples in the offline experiment. During actual operation, the currently collected load feature vector will be used... The weighted Euclidean distance between the five standard state points is calculated using the following formula: in Let j be the characteristic parameters of the j-th standard load. This indicates five load types. The weighting coefficients are determined based on the sensitivity of each parameter to the voltage regulation effect, and are set to [value missing]. ; Select weighted Euclidean distance The smallest standard load type is taken as the current load type k. To quantify the reliability of the identification results, the load feature identification module uses a Gaussian membership function to calculate the load state membership degree corresponding to the minimum weighted Euclidean distance. The calculation formula is as follows: in The minimum weighted Euclidean distance is... The width parameter of the membership function. Membership degree is the membership degree of the load state. The range of values ​​is ,when This indicates that the current load characteristics are highly consistent with the standard load. This indicates that the current load is in a transitional state between two types or a mixed state of multiple loads. Membership information is passed to the adaptive voltage regulation decision module to adjust the aggressiveness of the control strategy.

[0022] like Figure 2 As shown, in one embodiment of the present invention, the adaptive voltage regulation decision module selects the corresponding voltage regulation gain coefficient based on the current load type k provided by the load feature identification module. Different load types correspond to different gain coefficient values. In a specific embodiment, a resistive load... High power factor inductive load Low power factor inductive load capacitive load Nonlinear load ; The adaptive voltage regulation decision module applies a test voltage perturbation to the output of the energy-saving device to detect the gradient of energy transfer efficiency with respect to voltage, at the current output voltage. Apply amplitude on the basis The test voltage disturbance, of which This indicates the output voltage value at the current moment. With a rated voltage of 220V, the disturbance amplitude is approximately 1.1V. The disturbance is maintained for 3 power frequency cycles (60ms). The efficiency before the disturbance is measured. and efficiency after perturbation ,in This represents the time interval during which the disturbance lasts, used to calculate the change in efficiency. Energy transfer efficiency is defined as ,in and These are the active power at the output and input terminals, respectively. The gradient of energy transfer efficiency with respect to voltage is calculated using a numerical differential method. The calculation formula is as follows: When the efficiency gradient is positive, it indicates that the efficiency increases along the direction of increasing voltage, meaning that the current voltage is too low and the voltage should be increased. When the efficiency gradient is negative, it indicates that the efficiency increases along the direction of decreasing voltage, meaning that the current voltage is too high and the voltage should be decreased. The absolute value of the efficiency gradient reflects the distance from the optimal point. To ensure the accuracy of gradient measurement, the adaptive voltage regulation decision module detects the load power fluctuation rate before applying the test voltage disturbance. The load power fluctuation rate is defined as the ratio of the standard deviation of power to the average value within 10 consecutive sampling periods (1 second). When the power fluctuation rate exceeds the preset threshold of 10%, it is determined that the load is in a dynamic state. At this time, the gradient detection is paused and the current voltage level is kept unchanged. The normal voltage regulation decision process is resumed after the load stabilizes. The adaptive voltage regulation decision module calculates the continuous voltage adjustment based on the efficiency gradient, the voltage regulation gain coefficient, and the deviation between the current efficiency and the reference efficiency using a nonlinear coupling algorithm. The calculation formula is as follows: in This is a continuous voltage adjustment amount. This is the voltage regulation gain coefficient. To determine the direction of voltage regulation, the sign function of the efficiency gradient is extracted. hour make Increase voltage, when hour make Reduce voltage, The gradient of energy transfer efficiency with respect to voltage. It is a non-linear exponent. For efficiency reference, The energy transfer efficiency at the current moment; Nonlinear exponent Based on load status membership Dynamic adjustment, calculation formula is: When the load characteristics are stable Approaching 1 Reducing the voltage to around 0.3 results in a smoother and more stable voltage regulation response, especially when the load characteristics are unstable. Reduce to below 0.5 Increasing it to above 0.6 makes the voltage regulation response more sensitive to track rapidly changing loads; Reference efficiency Set as the highest efficiency value recorded during historical operation. 98% of For newly commissioned equipment, The initial value was set to 0.92, and after running for one week, the actual recorded values ​​were used... Updated to ; This nonlinear coupling algorithm achieves dual nonlinear coupling of gradient information and deviation information. When the system is far from the optimal point, the gradient and deviation are large, and the product of the two terms produces a large voltage regulation amplitude to achieve rapid approximation. When the system is close to the optimal point, the gradient or deviation is small, and the nonlinear characteristics of the two terms cause the voltage regulation amplitude to automatically decrease to avoid exceeding the optimal point.

[0023] like Figure 3 As shown, in one embodiment of the present invention, the gear position execution and feedback module is responsible for processing the continuous voltage adjustment amount output by the adaptive voltage regulation decision module. Converted into actual gear shifting commands; The main circuit of the electromagnetic balancing energy saver includes a main transformer and multiple voltage regulating taps. Different taps are selected via an electronic switch array or on-load tap changer to achieve graded voltage regulation. The energy saver is designed with multiple output voltage levels; in one specific embodiment, it has seven output voltage levels, corresponding to output voltages of 100%, 97%, 94%, 91%, 88%, 85%, and 82% of the rated voltage, respectively. The voltage difference between adjacent levels is... 3% of the rated voltage ; The method by which the gear shifting and feedback module maps continuous voltage adjustment amounts to discrete gear shifting commands is as follows: based on the continuous voltage adjustment amount... Voltage difference between adjacent gears The gear shift change is calculated using the following formula: in This is the rounding function. This represents the change in voltage level; a positive value indicates upshifting (increasing voltage) and a negative value indicates downshifting (decreasing voltage). Set the current gear With gear change Add them together to get the target gear. To limit the target gear to within the effective gear range, the limiting formula is as follows: Where N is the total number of gears, ensuring that the target gear is neither lower than the first gear nor higher than the Nth gear; When the target gear With the current gear The gear shifting action is not performed simultaneously. The gear shifting is achieved by controlling the electronic switch array or on-load tap changer of the main circuit. First, the switch corresponding to the current gear is opened, and after a 5ms delay, the switch corresponding to the target gear is closed to complete the shifting process. The purpose of the delay is to avoid the influence of electric arc during switch switching. After the gear shifting action is completed, the system waits for the load to reach a steady state. The steady-state criterion is that the fluctuation rate of the output voltage and current is less than 2% for two consecutive power frequency cycles. The gear shifting and feedback module evaluates the change in the load characteristic vector after voltage regulation, re-acquires the voltage and current data after voltage regulation, and calculates the load characteristic vector after voltage regulation. And the efficiency after voltage regulation Calculate the load characteristic vector before voltage regulation. With the load characteristic vector after voltage regulation The Euclidean distance is used as the phase trajectory offset, and the calculation formula is: Set offset threshold This value is a dimensionless Euclidean distance, which is set based on the fact that the minimum distance between the five standard load types measured in the offline experiment is about 0.5, and 30% of it is taken as the threshold. When phase trajectory offset Exceeding the preset offset threshold This indicates that voltage regulation has caused a change in the load's operating state, triggering the load characteristic identification module to re-identify the load type and update the load type judgment. The gear execution and feedback module adaptively adjusts the voltage regulation gain coefficient based on the degree of agreement between the actual and expected voltage regulation effects, and calculates the voltage regulation effect evaluation coefficient. in This refers to the efficiency after voltage regulation. Efficiency before voltage regulation. Evaluation coefficients are used to measure the change in efficiency during test disturbances. This reflects the degree to which the actual voltage regulation effect matches the expected effect; ideally... It should be close to 1; When the voltage regulation effect evaluation coefficient When the voltage regulation gain coefficient is below the preset value of 0.8, an adaptive correction is performed. The correction formula is as follows: in This is the voltage regulation gain coefficient before correction. The corrected voltage regulation gain coefficient is when The gain coefficient remains constant when The gain coefficient decreases proportionally to reduce the aggressiveness of voltage regulation. The gain coefficient is increased proportionally to accelerate the optimization process. Through this closed-loop feedback mechanism, the system can continuously track load changes and optimize control parameters, achieving true adaptive voltage regulation control. The voltage regulation decision cycle is set to 10 seconds. Each cycle executes a complete process of feature recognition, gradient testing, voltage regulation decision, gear execution, and effect evaluation. The 10-second cycle can respond to load changes in a timely manner while avoiding the impact of excessively frequent gear switching on the lifespan of the electronic switch.

[0024] In one embodiment of the present invention, the health monitoring module uses the equipment health parameters obtained by the data acquisition module to promptly detect potential equipment failure risks through threshold judgment and cumulative damage assessment. The parameters monitored by the health monitoring module include the core temperature of the main transformer of the energy-saving device. When the core temperature exceeds the warning threshold The system will issue a warning indicating poor heat dissipation or overload operation, and recommends checking the ventilation environment. The alarm threshold will be exceeded. An alarm is triggered and the energy-saving device is automatically switched to bypass direct-connect mode. In bypass direct-connect mode, the input and output terminals of the energy-saving device are directly connected without voltage regulation to avoid overheating and damage to the equipment. The system waits until the core temperature drops to a safe level. Normal voltage regulation mode can be resumed under the following conditions; The health monitoring module also monitors the number of gear shifts. Based on the cumulative number of switches Number of switching cycles with rated life The ratio is used to calculate the contactor life consumption rate. The rated life of the contactor is set as follows: When the lifespan consumption rate exceeds the preset threshold of 0.8, a warning is issued indicating that the contactor is nearing the end of its lifespan and a replacement plan is recommended. When the lifespan consumption rate exceeds 0.95, an alarm is issued recommending immediate shutdown for inspection and replacement of the contactor to prevent contactor failure and equipment malfunction. The health monitoring module also monitors the insulation resistance of the main circuit to ground. When the insulation resistance is lower than the qualified threshold If an alarm is triggered, it indicates that the insulation performance has deteriorated and there is a risk of leakage. It is recommended to stop the machine for inspection and check whether the insulation material is damp or aged. The above three indicators monitor the health status of the equipment from three dimensions: heat loss, mechanical loss, and electrical insulation. The monitoring data is displayed in real time on the local human-machine interface of the equipment, and is also uploaded to the remote monitoring platform through RS485 communication interface or Ethernet interface, so as to realize the visualized management and preventive maintenance of the equipment health status.

[0025] Through the coordinated operation of the five modules mentioned above, the system of this invention achieves a leap from a single power factor parameter to a multi-dimensional comprehensive characterization of the load's dynamic impedance characteristics by employing three-dimensional characteristic quantities of voltage and current phase trajectories. This effectively distinguishes different load types and quantifies the reliability. The dual nonlinear coupling voltage regulation algorithm based on the energy transfer efficiency gradient enables the voltage regulation amplitude to adaptively change with load characteristics and optimization progress, ensuring rapid convergence when far from the optimum while avoiding oscillations when approaching the optimum. The closed-loop feedback mechanism, by evaluating the load characteristic offset and voltage regulation effect evaluation coefficient after voltage regulation, achieves dynamic tracking of the load type and adaptive correction of the gain coefficient, enabling the system to continuously optimize the control strategy to adapt to dynamic load changes. The integrated equipment health monitoring function perceives the equipment status in real time from three dimensions: temperature rise, mechanical life, and insulation performance, improving the reliability of the equipment throughout its entire lifecycle. The overall technical solution fundamentally solves the technical problem that fixed voltage regulation strategies cannot adapt to load differences and dynamics, achieving an organic unity of energy saving and control stability under different load conditions.

[0026] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An intelligent control system for an electromagnetic balancing power saver, characterized by, The application relates to a power-saving device and a power-saving method. The data acquisition module is used for acquiring voltage and current instantaneous values of an input end and an output end of the power-saving device. The load characteristic identification module is used for constructing a voltage-current phase locus based on the voltage and current instantaneous values, extracting an area proportion coefficient, a phase shift index and a waveform distortion index of the phase locus as a load characteristic vector to represent a load impedance characteristic, matching the real-time acquired load characteristic vector with a preset standard load characteristic library to determine a current load type. The adaptive voltage regulation decision module is used for selecting a corresponding voltage regulation gain coefficient according to the current load type, applying a test voltage disturbance to the output end of the power-saving device to detect a gradient of energy transmission efficiency to voltage, and calculating a continuous voltage adjustment amount through a nonlinear coupling algorithm based on the efficiency gradient, the voltage regulation gain coefficient and a deviation of the current efficiency from a reference efficiency. The gear execution and feedback module is used for mapping the continuous voltage adjustment amount into discrete gear switching instructions to control the power-saving device to switch to a target gear, and evaluating a change of the load characteristic vector after voltage regulation, and triggering the load characteristic identification module to re-identify the load type if the change exceeds a threshold value, and adaptively correcting the voltage regulation gain coefficient according to a fitting degree of an actual voltage regulation effect and an expected effect. The health monitoring module is used for monitoring a core temperature, a gear switching frequency and a main circuit ground insulation resistance of the power-saving device, and giving a warning when the monitoring parameters exceed preset thresholds.

2. The intelligent control system of an electromagnetic balancing power saver according to claim 1, wherein, The sampling frequency of the data acquisition module is set as 128 times of a power frequency, and 128 voltage and current instantaneous value data points are acquired in each power frequency cycle; the data acquisition module is also used for measuring active powers at the input end and the output end of the power-saving device, and the power measurement adopts a digital sampling method to obtain the active powers through numerical integration of the voltage and current instantaneous value products in one power frequency cycle.

3. The intelligent control system of an electromagnetic balancing power saver according to claim 2, wherein, Area ratio coefficient Area ratio coefficient Peak voltage Peak current The ratio of the rectangular area is calculated as follows: where the phase trajectory closed envelope area The trapezoidal integration method is used, i.e. , and are the voltage and current instantaneous values at the nth sampling point; Phase shift index defined as the power factor arccosine value normalized, calculated as: wherein cos φ is the power factor; Waveform distortion index The waveform distortion index is defined as the ratio of the root mean square of the 2nd to 13th harmonic current effective values to the fundamental current effective value, and is calculated by the following formula: wherein is the effective value of the hth harmonic current, obtained by fast Fourier transform, is the effective value of the fundamental current, is the highest harmonic number considered.

4. The intelligent control system of an electromagnetic balancing power saver according to claim 3, wherein, The method for matching the real-time acquired load characteristic vector with the preset standard load characteristic library is as follows: Computing real-time load feature vectors The weighted Euclidean distance between each standard load feature vector in the standard load feature library and the real-time load feature vector is calculated according to the following formula: wherein subscript t represents a current time, is a characteristic vector of the jth standard load, is a weighting coefficient, and a weighted Euclidean distance is selected the smallest standard load type is taken as the current load type k; The Gaussian membership function is used to calculate a load state membership degree corresponding to a minimum weighted Euclidean distance, and a calculation formula is as follows: wherein is the minimum weighted Euclidean distance, is a width parameter of the membership function, is the load state membership.

5. The intelligent control system for electromagnetic balancing power saver as claimed in claim 1 wherein, The method for applying the test voltage disturbance to the output end of the power-saving device to detect the gradient of the energy transmission efficiency to the voltage is as follows: at the current output voltage a test voltage disturbance of amplitude is applied on the basis of the rated voltage, where the disturbance is maintained for 3 power frequency cycles, the efficiency before the disturbance and the efficiency after the disturbance are measured, and the change in efficiency is calculated, where denotes the time interval during which the disturbance is maintained. The gradient of the energy transfer efficiency with respect to the voltage is calculated using a numerical differentiation method, and the formula is ; The load power fluctuation rate is detected before the test voltage disturbance is applied, and the gradient detection is suspended and the current gear is kept unchanged when the power fluctuation rate exceeds a preset threshold.

6. The intelligent control system for electromagnetic balancing power saver as claimed in claim 1 wherein, The calculation formula of the nonlinear coupling algorithm is as follows: wherein is the continuous voltage adjustment, is the voltage adjustment gain coefficient, is the sign function of the efficiency gradient, is the gradient of the energy transfer efficiency with respect to the voltage, is the non-linear exponent, is the reference efficiency, is the energy transfer efficiency at the current time instant t; where the non-linear index According to the load state membership degree Dynamic adjustment, the calculation formula is: Reference efficiency Set to the highest efficiency value recorded during the historical run 98%, i.e. .

7. The intelligent control system for electromagnetic balancing power saver as claimed in claim 1 wherein, The method for mapping the continuous voltage adjustment amount into the discrete gear switching instructions is as follows: According to the continuous voltage adjustment amount And the voltage difference between adjacent gears The gear change amount is calculated, and the calculation formula is: wherein is a rounding function, is a gear change amount; the current gear and the gear change amount to obtain a target gear , the target gear is limited to be within a valid gear range, and when the target gear is different from the current gear , a gear shifting action is performed.

8. The intelligent control system of an electromagnetic balancing power saver according to claim 3, wherein, The evaluation of the change of the load characteristic vector after voltage regulation includes as follows: Computing the euclidean distance between the pre-regulation load eigenvector and the post-regulation load eigenvector as the phase trajectory offset, the formula is: When the phase trajectory offset amount exceeds a preset offset threshold the load feature recognition module is triggered to re-identify the load type; The adaptive correction of the voltage regulation gain coefficient according to the fitting degree of the actual voltage regulation effect and the expected effect includes as follows: The voltage regulation effect evaluation coefficient is calculated as follows: Wherein is the efficiency after voltage regulation, is the efficiency before voltage regulation, is the amount of efficiency change measured when the test disturbance occurs, and when the voltage regulation effect evaluation coefficient is lower than the preset value, the voltage regulation gain coefficient is adaptively corrected, and the correction formula is: wherein, is the uncorrected voltage regulating gain coefficient, is the corrected voltage regulating gain coefficient.

9. The intelligent control system for electromagnetic balancing power saver as claimed in claim 1 wherein, The parameters monitored by the health monitoring module include as follows: Power saver main transformer core temperature When the core temperature exceeds a pre-warning threshold a pre-warning is issued and when the core temperature exceeds an alarm threshold the power saver is automatically switched to a bypass mode Number of gear shift , the contactor life consumption rate is calculated from the ratio of the cumulative number of shifts to the rated number of shifts ; and an early warning or alarm is issued when the life consumption rate exceeds a preset threshold. Main circuit earth insulation resistance An alarm is issued when the insulation resistance is below a qualifying threshold .

10. The intelligent control system for electromagnetic balancing power saver as claimed in claim 1 wherein, The standard load characteristic library includes standard characteristic vectors of five typical load types, i.e. pure resistive load, high power factor inductive load, low power factor inductive load, capacitive load and nonlinear load; and the voltage regulation gain coefficient According to the load type determination, different load types correspond to different gain coefficient values; the power saver is designed with multiple output voltage levels, and the voltage difference between adjacent levels is 3% of the rated voltage; the voltage regulation decision period is set to 10 seconds, and a complete characteristic identification, gradient test, voltage regulation decision, level execution and effect evaluation process is performed once every period.

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