Low-voltage line intelligent voltage regulation voltage stabilizer control system

Abstract

The invention discloses a low-voltage line intelligent voltage regulation voltage stabilizer control system, and relates to the technical field of voltage stabilizer control, an intelligent control unit judges whether the current line voltage needs voltage regulation control based on a control algorithm, if yes, a corresponding voltage regulation control instruction is generated, a silicon controlled rectifier switching module executes non-contact on and off operation, and the voltage regulation control is completed. The voltage regulation compensation module is used for carrying out voltage compensation on the basis of the output of the voltage transformation module, so that the output voltage is controlled within a preset range, and when the power grid voltage is detected to be recovered and stable within a set time, and when the power grid voltage is detected to be abnormal, the voltage regulation compensation module is used for carrying out voltage compensation on the basis of the output of the voltage transformation module. And the intelligent control unit is automatically switched into a bypass for operation. According to the control system, a voltage stabilization control framework with high response speed, three-phase independent adjustment capability, an intelligent dormancy mechanism and a complete fault protection system is constructed, and the intelligent level and the operation performance of the low-voltage power distribution system are remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of voltage stabilizer control, and in particular to a low-voltage line intelligent voltage regulating voltage stabilizer control system. Background Art

[0002] The low-voltage line intelligent voltage regulator is a voltage quality optimization device used at the end of the distribution line. It is mainly used to solve the problem of low or fluctuating voltage caused by long lines and large load fluctuations. With the increase in the uncertainty of distributed energy access and power load, traditional voltage stabilization methods can no longer meet the high requirements of modern distribution systems for power supply quality. For this reason, intelligent voltage regulators have come into being. They have automatic detection, intelligent judgment and rapid response capabilities, and can realize functions such as graded voltage regulation, stepless regulation and remote control. Its control system is the core component, responsible for real-time collection of parameters such as voltage and current, using control algorithms to intelligently judge the operating status, and driving the actuator to accurately adjust the voltage.

[0003] The existing technology has the following defects: 1. Traditional voltage stabilizers mostly rely on mechanical contacts or relays to switch voltage levels, which can lead to contact erosion, switching hysteresis, and voltage jumps, seriously affecting system stability and the safe operation of electrical equipment. Furthermore, they use a unified three-phase linkage voltage regulation system, lacking the ability to independently adjust single-phase voltage imbalances and unable to effectively cope with complex three-phase load imbalance environments. 2. Existing equipment often continues to operate the main voltage regulation module after the voltage stabilizes, resulting in long-term high power consumption, causing energy waste and increased wear and tear of key components. In abnormal situations, there is also a lack of a fast and accurate bypass protection mechanism, making it difficult to ensure power supply continuity and equipment safety.

[0004] Based on this, the present invention proposes a low-voltage line intelligent voltage regulator and voltage stabilizer control system, constructs a voltage stabilization control architecture with high response speed, three-phase independent regulation capability, intelligent sleep mechanism and complete fault protection system, which significantly improves the intelligence level and operation performance of the low-voltage power distribution system. Summary of the Invention

[0005] The purpose of the present invention is to provide a low-voltage line intelligent voltage regulating and stabilizing control system to solve the problems in the background technology.

[0006] In order to achieve the above-mentioned object, the present invention provides the following technical solutions: a low-voltage line intelligent voltage regulator control system, comprising an information acquisition and processing unit, an intelligent control unit, a thyristor switching module, a voltage transformation module and a voltage regulation compensation module; The information collection and processing unit is used to collect and process the electrical parameters of the three-phase input line in real time after the equipment is powered on; The intelligent control unit determines whether the current line voltage needs voltage regulation based on the control algorithm, and if so, generates the corresponding voltage regulation control instruction; The thyristor switching module performs contactless on and off operations to switch the corresponding voltage regulation gear and control the winding connection mode of the transformer module; A voltage conversion module, used to complete voltage conversion under the control of the thyristor switching module; A voltage regulating and compensating module is used to perform voltage compensation based on the voltage conversion of the transformer module, so that the output voltage is controlled within a preset range; Wherein, when a phase voltage is abnormal, the intelligent control unit independently adjusts the phase voltage regulation compensation module; When it is detected that the grid voltage has recovered and stabilized within a set time, the intelligent control unit controls the thyristor switching module to stop the main voltage regulation circuit from running, switch to bypass power supply and enter sleep mode; When an abnormality is detected, the intelligent control unit automatically switches to bypass operation.

[0007] Preferably, the intelligent control unit is embedded with an intelligent judgment and control algorithm, which includes voltage state judgment logic, three-phase imbalance recognition logic, voltage regulation decision logic, sleep judgment logic and abnormal protection logic.

[0008] Preferably, the voltage state judgment logic is based on comparing the effective value of the three-phase voltage with a preset reference voltage, and adopts a floating tolerance interval judgment method to determine the voltage state, which is divided into an overvoltage zone, an undervoltage zone and a stable zone; The three-phase imbalance identification logic calculates the average value of the three-phase voltage and calculates the relative deviation rate between each phase and the average value. If the deviation rate of any phase exceeds the deviation rate threshold, it is marked as a voltage imbalance state and the unbalanced phase is identified.

[0009] Preferably, after identifying voltage deviation or imbalance, the voltage regulation decision logic generates a voltage regulation control instruction based on a control algorithm. The control algorithm includes a fuzzy mapping rule based on error and change rate, generates voltage regulation direction, voltage regulation phase and voltage regulation amount through error calculation and dynamic weight control, and constructs a data packet containing voltage regulation instruction type, execution priority and output control amount.

[0010] Preferably, the sleep determination logic is used to monitor whether the voltage is stable within a set range over a plurality of consecutive sampling periods, and whether the fluctuation amplitude is less than a preset fine-tuning threshold, and if there is no overcurrent or imbalance state, automatically determine it as a sleep candidate state and output a sleep control instruction; The abnormal protection logic is used to automatically generate a bypass switching instruction when it detects that the input voltage exceeds the limit, the output voltage cannot return to stability, there is overcurrent, or a system component failure.

[0011] Preferably, the thyristor switching module reads the current thyristor conduction state and transformer winding connection information through a local state cache and feedback mechanism, and outputs a state holding signal if the current state is consistent with the target state; if there is a difference, it enters the switching preparation stage; By real-time sampling of the three-phase voltage or current waveform, predicting the arrival time of the next zero-crossing point, and controlling the internal timer based on the target trigger type, the thyristor trigger pulse signal is output at the predetermined time point for disturbance-free conduction and disconnection. If a synchronous trigger mark is provided, the three-phase thyristors are controlled to complete switching at the same relative moment.

[0012] Preferably, the thyristor switching module includes a thyristor array control unit, which includes multiple thyristors or bidirectional thyristor branches for constructing a winding tap combination path. After receiving a trigger signal, the current path is disconnected and the target winding channel is turned on according to the control logic. If the target configuration includes multiple windings or cross-connections, they are gradually turned on in a preset order.

[0013] Preferably, the control instruction includes an operation type, an operation phase, a target voltage regulation gear or a winding combination, a synchronization mark and a check code.

[0014] Preferably, the information acquisition and processing unit acquires voltage and current analog signals of the three-phase input line; The collected signal enters the analog low-pass filter circuit to filter out high-frequency noise and harmonic interference, and the filtered signal is input to the analog-to-digital converter; The digital signal after analog-to-digital conversion undergoes zero offset correction and gain correction and is converted into voltage and current values; The information acquisition and processing unit performs real-time electrical parameter characteristic calculation on each phase; Various electrical parameter characteristics are combined into structured data packets, including three-phase voltage, current effective value, frequency, phase difference, voltage balance and status flags.

[0015] Preferably, the information acquisition and processing unit performs real-time electrical parameter characteristic calculation on each phase, comprising the following steps: Calculate the effective value of each phase voltage and current through the sliding window algorithm; Based on the zero-crossing point detection of the voltage waveform, the cycle length between two consecutive positive zero-crossing points is obtained, and the current frequency is calculated based on its reciprocal; The power factor is estimated by calculating the phase difference between the main frequency sinusoidal components of the voltage and current signals; Compare the three-phase voltage RMS values ​​in real time and calculate the relative deviation rate from the average value to determine whether the three-phase voltage is unbalanced.

[0016] In the above technical solution, the technical effects and advantages provided by the present invention are: The present invention uses an intelligent control unit to determine whether the current line voltage requires voltage regulation based on a control algorithm. If so, it generates corresponding voltage regulation control instructions. The thyristor switching module performs contactless on and off operations to switch the corresponding voltage regulation gear and control the winding connection method of the transformer module. The voltage regulation compensation module is used to perform voltage compensation based on the output of the transformer module to control the output voltage within a preset range. When it is detected that the grid voltage has recovered and stabilized within a set time, the intelligent control unit controls the thyristor switching module to exit the main voltage regulation circuit, switch to bypass power supply, and enter sleep mode. When an abnormality is detected, the intelligent control unit automatically switches to bypass operation. This control system constructs a voltage stabilization control architecture with high response speed, three-phase independent regulation capability, intelligent sleep mechanism, and a complete fault protection system, significantly improving the intelligence level and operational performance of the low-voltage power distribution system. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments described in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0018] Figure 1 It is a framework diagram of the system of the present invention. DETAILED DESCRIPTION

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0020] Example 1: Please refer to Figure 1 As shown, this embodiment provides a low-voltage line intelligent voltage regulator control system, including an information acquisition and processing unit, an intelligent control unit, a thyristor switching module, a voltage transformation module and a voltage regulation compensation module; When the device is powered on and begins operation, the information acquisition and processing unit starts first, responsible for real-time acquisition of key parameters such as the three-phase input line voltage and current, and filtering, converting, and digitizing the acquired signals. The acquired data includes instantaneous voltage, current, frequency, and phase angle, which are used to determine whether the current line voltage is within the preset stability range.

[0021] The processed electrical parameter data is transmitted to the intelligent control unit in real time. As the core "brain" of the system, the unit has built-in intelligent algorithms (such as PID regulation, fuzzy control or AI optimization strategy) to judge the voltage status based on the collected data, including: whether it exceeds the set ± stability range; whether there is three-phase voltage imbalance; whether the current voltage regulation status needs to be adjusted; whether the sleep condition is reached or a fault exists.

[0022] Based on the intelligent judgment results, if the system identifies voltage deviation or imbalance, the intelligent control unit will calculate the required voltage regulation compensation amount (amplitude and phase difference) and send specific voltage regulation instructions to the thyristor switching module and the voltage regulation compensation module.

[0023] After receiving the control signal, the thyristor switching module performs high-speed, contactless on and off operations, quickly selecting the appropriate voltage regulation position and transformer winding connection method. Its response time can reach milliseconds, ensuring uninterrupted and jump-free voltage regulation.

[0024] At the same time, the transformer module realizes basic voltage conversion under the guidance of thyristor switching, while the voltage regulation and compensation module further implements fine-tuning compensation based on the main transformer output to ensure that the output voltage is strictly controlled within ±2%, meeting the stable output requirements of 380V or 220V.

[0025] If only one of the three phases has an abnormality, the control system can identify the specific unbalanced phase and call the voltage regulation compensation module to perform independent voltage regulation on that phase only, without the need to adjust the three phases as a whole, accurately dealing with the three-phase voltage imbalance problem.

[0026] After the grid voltage returns to stability and continues to meet the set time conditions, the intelligent control unit determines that the line voltage has entered a stable state and automatically sends a switching instruction to the thyristor switching module, guiding the equipment to enter intelligent sleep mode: the voltage regulation related modules (main transformer, compensation transformer, thyristor) exit operation, the load is directly powered by the bypass, and only the information collection part is retained for continuous monitoring, minimizing equipment energy consumption and component wear.

[0027] During operation, if an abnormality is detected, such as input overvoltage / undervoltage, output abnormality, overcurrent, or device fault, the intelligent control unit immediately instructs the bypass system to switch into operation, seamlessly switching the load to the direct power supply path, protecting the terminal equipment and avoiding power outages. Fault information is also fed back to the host computer or remote monitoring system, facilitating a quick response from maintenance personnel.

[0028] This application uses an intelligent control unit to determine whether the current line voltage needs voltage regulation control based on a control algorithm. If necessary, it generates a corresponding voltage regulation control instruction. The thyristor switching module performs contactless on and off operations to switch the corresponding voltage regulation gear and control the winding connection method of the transformer module. The voltage regulation compensation module is used to perform voltage compensation based on the output of the transformer module to control the output voltage within a preset range. When it is detected that the grid voltage has recovered and stabilized within a set time, the intelligent control unit controls the thyristor switching module to exit the main voltage regulation circuit, switch to bypass power supply and enter sleep mode. When an abnormality is detected, the intelligent control unit automatically switches to bypass operation. This control system has constructed a voltage stabilization control architecture with high response speed, three-phase independent regulation capability, intelligent sleep mechanism and complete fault protection system, which significantly improves the intelligence level and operation performance of the low-voltage power distribution system.

[0029] Example 2: 1) When the device is powered on and begins operation, the information acquisition and processing unit starts first, responsible for real-time acquisition of key parameters such as the three-phase input line voltage and current, and filtering, converting, and digitizing the acquired signals. The acquired data includes instantaneous voltage, current, frequency, phase angle, etc., which are used to determine whether the current line voltage is within a preset stability range.

[0030] When the device is powered on and begins operation, the information acquisition and processing unit starts first. Its main task is to collect and pre-process the key electrical parameters of the three-phase input line in real time with high precision and low latency. This process is of decisive significance for the subsequent judgment and voltage regulation control of the intelligent control unit. The process generally includes the following main steps: The information acquisition and processing unit collects analog voltage and current signals from the A, B, and C three-phase lines using a precision voltage sampling module and current transformers (such as Hall sensors or resistor sampling). To ensure safety and anti-interference capabilities, the signals first undergo optoelectronic isolation or transformer isolation to ensure complete electrical isolation between the subsequent acquisition circuits and the high-voltage main circuit.

[0031] The collected analog signals often contain high-frequency noise and harmonic interference in addition to the power frequency signal (50Hz or 60Hz). Therefore, before entering the ADC (analog-to-digital converter), they must first be processed by an analog low-pass filter. The cutoff frequency is usually set slightly higher than the power frequency (such as 300Hz~1kHz) to suppress high-frequency interference signals and improve measurement accuracy and stability.

[0032] The filtered analog signal is converted to digital using a multi-channel, high-precision ADC chip. Sampling accuracy is typically no less than 12 bits, and the recommended sampling frequency is between 2 and 10 kHz. To ensure that voltage and current are sampled simultaneously (to avoid phase deviation), a synchronous trigger mechanism (such as a PWM interrupt or timer-based synchronous sampling) is used to ensure consistent sampling time for each phase's electrical parameters.

[0033] After analog-to-digital conversion, the digital signal requires linear calibration and amplitude normalization to eliminate deviations caused by sensor and channel errors or temperature drift. The calibration process includes zero offset correction and gain correction, typically performed using calibration coefficients. Normalization converts the ADC output value into actual engineering quantities (in units of volts and amperes) for subsequent calculations.

[0034] The information processing unit needs to perform a series of real-time calculations on each phase sample value to extract the electrical parameter characteristics required for voltage regulation control. This mainly includes the following core calculation logic: Each sampling cycle directly records the instantaneous values ​​of voltage and current, which serve as the basis for constructing cycle parameters. A sliding window calculation method is used to obtain the effective value of voltage or current over a period (e.g., 20ms) for determining the voltage regulation status. The calculation logic is as follows: For each channel, each sampling point within the sampling window is squared, averaged, and then square rooted. The sliding window is continuously updated, and the effective value is refreshed in real time. For example, the effective value of voltage is calculated as follows: "Square all voltage sampling points within the current sliding window, average them, and then take the square root." If 200 points are sampled per cycle, the window length is 200 data points, and the step size can be set to 1.

[0035] The cycle is calculated based on voltage zero-crossing detection and then the reciprocal is taken. The processing logic is as follows: the time between two consecutive positive zero-crossings (i.e., the intersection of the voltage from negative to positive) is recorded; a high-precision timer is used to record the time difference, and the reciprocal is taken as the current frequency. If the cycle is unstable, an average filter is used for smoothing.

[0036] The power factor is estimated by calculating the phase difference between the voltage and current through cross-correlation of the sampling points. This is used to evaluate load characteristics. The calculation method can be based on Fourier decomposition or time difference measurement. The main frequency sinusoidal components of the voltage and current are taken and their phase difference is calculated. The power factor is approximately the "cosine angle of the voltage and current waveforms."

[0037] Compare the RMS values ​​of the three-phase voltages in real time to determine whether they exceed the preset balance threshold (such as ±5%). For example, if U_A = 220V, U_B = 210V, and U_C = 230V, the balance is ±10V, and the relative deviation reaches ±4.5%, which is still within the control range. If the deviation exceeds the set threshold (such as ±10%), the independent phase voltage regulation logic is triggered.

[0038] Effective value calculation logic, for N consecutive sampling points in the sliding window The following processing is performed: Calculate the effective value of voltage (or current): The sliding window period N can be the number of sampling points in a full cycle (such as 200 points @ 10kHz corresponding to 50Hz power supply), based on the time interval between two consecutive positive zero crossings , calculate the grid frequency: The zero crossing point is realized by detecting the sign change of the voltage signal from negative to positive, combining with the sampling period counter to accurately obtain the period length, synchronously sampling the voltage and current waveforms, extracting the main frequency sinusoidal component, and calculating its phase difference , estimate the power factor , the phase lock detection or least squares sine fitting method can be used to extract the sinusoidal main component by calculating the average value of the three-phase voltage , and calculate the relative deviation rate of each phase: If any phase A set threshold (such as +5%) is marked as an unbalanced state, which is used to encapsulate the characteristic quantities obtained by the above calculation into a structured data packet. The data packet includes: three-phase voltage and current effective values, frequency, phase difference, power factor, voltage balance state flag, abnormal flag, etc. The data packet is called by the upper control unit for voltage stabilization control and fault identification.

[0039] If the sampling frequency is 10 kHz, with 200 points per cycle, the phase A voltage sampling values ​​within the current cycle are {220, 221, 218, ..., 223}. Effective value calculation yields RMS_A = 219.6 V. The number of sampling points between two consecutive positive zero crossings is 200. This corresponds to a period of T = 200 × 0.1 ms = 20 ms, a frequency of f = 1 / T = 50 Hz, and three-phase effective voltage values ​​of U_A = 219.6 V, U_B = 221.2 V, and U_C = 211.8 V, with an average value of U_avg = 217.5 V. The relative deviations are δ_A = +0.96%, δ_B = +1.7%, and δ_C = –2.6%. Since δ_C exceeds ±2%, the system is judged to be slightly unbalanced.

[0040] Based on these characteristic quantities, the processing unit determines the current line status (normal, undervoltage, overvoltage, three-phase imbalance, abnormal frequency, etc.) and packages the processing results as structured data and uploads them to the intelligent control unit for subsequent control decisions. The data packet generally contains: three-phase voltage, effective current value, three-phase frequency, zero-sequence / negative-sequence components (if any), and three-phase voltage deviation indicators. Through this entire process, the information acquisition and processing unit achieves precise processing from signal acquisition, filtering, synchronous sampling, feature calculation, to data collection and upload, providing a reliable, stable, and real-time data foundation for the subsequent intelligent control unit's precise judgment and control strategy generation. The accuracy and response speed at this stage directly determine the overall performance of the voltage regulator.

[0041] 2) The processed electrical parameter data is transmitted to the intelligent control unit in real time. This unit serves as the core "brain". The built-in intelligent algorithm (such as PID regulation, fuzzy control or AI optimization strategy) will judge the voltage status based on the collected data, including: whether it exceeds the set ± stability range; whether there is a three-phase voltage imbalance; whether the current voltage regulation status needs to be adjusted; whether the sleep condition is reached or a fault exists.

[0042] The control unit first compares the real-time three-phase voltage RMS values ​​received with a set stable reference voltage (e.g., 380V ± 2%). This comparison process does not rely on direct threshold determination, but rather uses a predefined floating tolerance interval judgment function to determine whether the current voltage is in the "overvoltage zone," "undervoltage zone," or "stable zone." A voltage state flag variable, such as V_state, is defined. If a phase voltage exceeds the upper stability threshold, that phase is marked as "overvoltage." If a phase voltage falls below the lower stability threshold, that phase is marked as "undervoltage." If all three phases are within the stable zone, the voltage is marked as "normal."

[0043] This process uses a judgment structure with hysteresis control logic to avoid frequent voltage adjustments caused by short-term fluctuations. For example, the threshold for entering voltage regulation is set to ±3%, while the threshold for exiting voltage regulation is set to ±2% to achieve jitter suppression.

[0044] While determining the overall voltage status, the control unit also calculates the balance between the three-phase voltages in real time. The core indicator is the relative difference between the three-phase voltages, calculated as follows: The three-phase voltage mean is calculated; the difference between each phase and the mean is calculated, and then divided by the mean to obtain the relative deviation rate. If the deviation rate of any phase exceeds the deviation rate threshold (e.g., 5%), it is marked as "unbalanced" and the unbalanced phase is recorded. For example, if the voltages of phases A, B, and C are 210V, 220V, and 240V, respectively, the three-phase average is 223.3V. Phase C has a relative deviation of +7.4%, exceeding the threshold and triggering the independent voltage regulation mechanism.

[0045] Once the voltage of a single phase or the three phases as a whole deviates from the preset range, the control unit enters the voltage regulation strategy decision process. This process is based on the built-in voltage regulation control algorithm. Common strategies currently include: the control target is to stabilize the output voltage at the set value; the deviation value (set value minus current value) is calculated in real time as the error; the output regulation variable is used to determine the gear or compensation percentage to be adjusted. The voltage error (E) and the error change rate (ΔE) are fuzzy mapped to a rule table; language rules (such as "If the error is large and increasing, adjust downward rapidly") are used to generate the fuzzy control variable; defuzzification is performed and the specific control action is output. This is suitable for applications with large operating condition uncertainty and high regulation sensitivity requirements.

[0046] Finally, based on the calculation results of the control algorithm, a voltage regulation control instruction data packet is generated. The instructions include: voltage regulation direction (boost or buck); voltage regulation phase (A / B / C or all phases); voltage regulation amount (which can be quantified as level gear or compensation percentage); execution priority (normal / emergency); the data packet is immediately sent to the thyristor switching module for execution.

[0047] To improve energy efficiency and extend the life of the device, the control unit has an embedded intelligent sleep determination mechanism. The determination logic is as follows: The system checks that the voltage remains within the set "stable range" for consecutive sampling periods (e.g., 10 seconds or 600 sampling frames). If the three-phase voltage remains stable and the recent voltage fluctuations are below the preset "fine-tuning threshold" (e.g., within ±1%), it enters the "sleep candidate state." It also verifies that there are no overcurrents or imbalances. Once these conditions are met, the system triggers the sleep process and issues a "exit voltage regulation and enter bypass" command to the thyristor module. In the sleep state, only the information acquisition and processing unit remains operational, while the remaining main voltage regulation modules are powered off to minimize losses.

[0048] The intelligent control unit continuously monitors the status, including input voltage, output voltage, current, circuit temperature, and device status flags. If any of the following abnormal conditions are met: input voltage exceeding a limit threshold (e.g., ±20%); output voltage fluctuating abnormally (unable to adjust to the target value); current exceeding the set upper limit (overload); or control or power component failure (e.g., abnormal conduction of a thyristor or abnormal temperature), the bypass switching mechanism is immediately activated: a "disconnect the voltage regulation circuit and connect to the bypass power supply" command is issued to the thyristor module; the output maintains power supply continuity to prevent load power loss; and the abnormal status information is packaged and uploaded to the remote monitoring interface.

[0049] The voltage state judgment logic is used to compare the floating tolerance interval of the three-phase voltage effective value with a preset reference voltage to determine the current line voltage state and classify it into an overvoltage zone, an undervoltage zone, or a stable zone. Specifically, when the difference between each phase voltage and the reference voltage is within the ± stability range (for example, ±2%), it is determined to be in the stable zone; if it is above the upper stability threshold, it is marked as the overvoltage zone; if it is below the lower stability threshold, it is marked as the undervoltage zone. The judgment process has hysteresis logic, and the voltage regulation entry threshold can be ±3% and the voltage regulation exit threshold is ±2% to avoid frequent jumps. For example, if the target voltage is 220V and the stability tolerance is set to ±2%, when the phase voltage reaches 226V (+2.7%), it enters the "overvoltage" zone and waits until the voltage drops below 224V (+1.8%) to exit the overvoltage state and enter the "stable zone."

[0050] The three-phase imbalance identification logic is used to determine whether there is an imbalance between the three-phase voltages. Specifically, it calculates the average value of the three-phase voltages, U_avg, which is (U_A+U_B+U_C) / 3. It also calculates the deviation rate of each phase: ΔU_A=(U_A-U_avg) / U_avg, ΔU_B=(U_B-U_avg) / U_avg, and ΔU_C=(U_C-U_avg) / U_avg. If the |ΔU_x| value of any phase exceeds the set imbalance threshold (for example, 5%), it is marked as unbalanced and the unbalanced phase is recorded. For example: If U_A = 218 V, U_B = 220 V, U_C = 233 V, and U_avg = 223.7 V, ΔU_C = (233 - 223.7) / 223.7 ≈ +4.1%, which does not exceed 5%, and the system remains normal. If phase C is 240 V, then ΔU_C ≈ +7.3%, and the system determines that phase C is unbalanced.

[0051] The voltage regulation decision logic is used to generate a voltage regulation control instruction based on an error feedback control algorithm when the voltage state is abnormal or unbalanced. The control algorithm includes: obtaining the voltage deviation E = U_ref - U_actual for each phase; obtaining the rate of change ΔE = E(t) - E(t-1); mapping E and ΔE into language quantities (such as "positive large", "negative small", etc.) based on a fuzzy control mapping rule table, and outputting the fuzzy regulation quantity U_ctrl; defuzzifying the fuzzy expression into a quantitative voltage regulation action, setting: voltage regulation direction (boost or buck); voltage regulation phase (single-phase or three-phase); voltage regulation amplitude (expressed as gear number or compensation percentage); constructing a voltage regulation control instruction package including fields such as voltage regulation type, control phase, target gear or compensation coefficient, execution priority, and synchronization flag. For example, if the current voltage of a phase is 208V and the target is 220V, E = +12V, and ΔE is positive, the system determines it as "rapid voltage boost", outputs a +2 gear voltage regulation instruction through table lookup, and generates a control frame.

[0052] The sleep determination logic is used to enter energy-saving mode when the voltage state is stable for a long time. Its processing logic includes: checking whether the voltage is within the set tolerance (such as ±1%) for multiple consecutive sampling periods; judging whether the fluctuation is less than the fine-tuning threshold (such as ±0.5V) and there is no overcurrent or imbalance; if the above conditions are continuously met for a preset length of time (such as 10 seconds), it is marked as a "sleep candidate state"; a sleep switching instruction is sent to the thyristor module and compensation module to disconnect the voltage regulation path and connect to the bypass power supply; for example: if the continuous detection value under the 220V target is 219.6~220.4V, there is no overcurrent / imbalance, and it lasts for 600 sampling frames, the system determines that it has entered the sleep state.

[0053] Abnormal protection logic is used to generate bypass switching instructions to ensure load power supply continuity when overvoltage, undervoltage, overcurrent, voltage regulation failure or equipment failure occurs. The processing flow includes: sampling to determine whether the input voltage exceeds the ±20% tolerance or the output voltage cannot be adjusted steadily; detecting whether there is an overload (output current exceeds 110% of the rated value); monitoring module internal temperature, communication status, power supply fluctuations, thyristor triggering abnormalities and other faults; if any abnormality is established, the bypass power supply path is first opened, then the voltage regulation module connection is disconnected, and finally the fault information is uploaded to the monitoring system.

[0054] The judgment logics can be based on sliding window filtering and hysteresis judgment mechanisms to improve control stability and response robustness, and support real-time event recording and remote abnormality alarm functions.

[0055] The intelligent control unit comprehensively monitors and assesses factors such as voltage deviation, phase balance, voltage stability, and faults. It then utilizes precise control algorithms to generate real-time voltage regulation commands and dynamically switch operating states (regulation, sleep, or bypass). Its decision-making process combines logical judgment with dynamic control, effectively achieving highly responsive, stable, and reliable voltage regulation, forming the core control mechanism for the entire intelligent voltage stabilizer.

[0056] 3) Based on the intelligent judgment results, if voltage deviation or imbalance is identified, the intelligent control unit will calculate the required voltage regulation compensation amount (amplitude and phase difference) and send specific voltage regulation instructions to the thyristor switching module and the voltage regulation compensation module.

[0057] The intelligent control unit determines the output voltage target value (such as the set benchmark of 380V or 220V) based on the current operating mode, and calculates the difference between it and the current actual voltage effective value of each phase to obtain the voltage deviation of each phase.

[0058] Instead of using the instantaneous value directly, the RMS value within the most recent sliding cycle is used to filter out the interference of instantaneous fluctuations on the judgment. The processing logic is as follows: For each phase (A, B, C), the voltage deviation is calculated as the target voltage minus the measured voltage. The deviation result can be positive (voltage boost required) or negative (voltage reduction required). The phase with the largest deviation is also recorded to determine whether it is a single-phase imbalance or a three-phase overall fluctuation. If only one phase deviates from the set value and exceeds the imbalance determination threshold (such as ±5%), it is considered a "local imbalance" and only that phase needs to be adjusted. If all three phases deviate, it is considered an "overall fluctuation" and the three-phase coordinated adjustment mode is entered.

[0059] To achieve actual voltage regulation, the deviation needs to be converted into a control signal. This process relies on a voltage regulation mapping model and is usually divided into two parts: A. Main transformer shift mapping (for large-scale compensation) Applicable to scenarios where the deviation is greater than a set value (e.g., ±5%), the control unit maps the voltage deviation to the corresponding winding tap position or gear number through a table lookup or linear conversion. The processing logic is as follows: divide the voltage deviation by the compensation capability of a single voltage regulation gear (e.g., ±2.5V per gear); round the number to the desired number of gears; if a voltage increase is required, adjust the gear up; if a voltage decrease is required, adjust the gear down; and limit the output gear to within a safe range (e.g., gears 0 to 8).

[0060] B. Compensation module adjustment coefficient calculation (for small or fine compensation) When the voltage deviation is less than the adjustment resolution of the main conversion gear (e.g., within ±2V), the voltage regulation compensation module is invoked to output an adjustable voltage in analog form, enabling fine-grained regulation. The control value is typically expressed as a percentage or PWM duty cycle. The processing logic is as follows: the current deviation is divided by the full-load output range of the compensation module to obtain a relative regulation coefficient. Based on the direction (up or down), a positive or negative regulation command is output. If the compensation module supports closed-loop feedback, the output value is fine-tuned based on the voltage response in the next cycle to achieve dynamic stable control. For example, if the current deviation is +1.8V and the compensation transformer's regulation capability is ±20V, the regulation coefficient is +9%. The control module sets the corresponding output level and monitors voltage feedback in real time for iterative fine-tuning.

[0061] After determining the regulation direction and magnitude for each phase, the intelligent control unit implements phase-specific regulation strategies. The logic is as follows: If an overall fluctuation is identified (i.e., the three-phase deviations are consistent in direction or collectively deviate from the target value), a three-phase synchronous voltage regulation strategy is adopted. If a single-phase imbalance is identified (e.g., only phase C is below the reference value), independent regulation is implemented for that phase. If there are staggered deviations (e.g., phase A is high, phase B is low, and phase C is normal), a hybrid voltage regulation strategy is implemented: synchronous shifting plus independent compensation. All regulation operations must ensure that the adjusted phase outputs do not introduce new imbalances, and a "balance check" is automatically added after the voltage regulation command.

[0062] After the above calculations are completed, the intelligent control unit will construct a standardized control instruction frame based on the device control protocol and send it to each execution module. The control instruction mainly includes: instruction type identification (gear adjustment, compensation, bypass, etc.); operation phase (A / B / C or ABC); gear number (such as gear adjustment to 3rd gear) or compensation percentage (such as +9%); priority mark (normal, emergency); check code and synchronization time stamp (used to ensure timing consistency); control frame is sent to: Thyristor switching module: used to perform main gear shifting operation; Voltage regulation compensation module: used to perform fine-tuning voltage compensation control.

[0063] After receiving the command, each module completes the corresponding physical action based on its local firmware logic and returns an execution confirmation flag. The control unit monitors the feedback status and triggers a retransmission mechanism or a backup plan (such as switching to bypass) if it detects no response or abnormal execution.

[0064] This step implements a complete closed-loop voltage regulation logic flow, from voltage deviation identification → voltage regulation amount calculation → phase strategy determination → precise command generation and transmission. It not only provides coarse and fine adjustment capabilities but also dynamically selects three-phase linkage or independent voltage regulation paths based on imbalance conditions. Through structured data processing and precise control, the output voltage quickly stabilizes, significantly improving the voltage regulator's operating efficiency, response speed, and output quality.

[0065] 4) After receiving the control signal, the thyristor switching module performs high-speed, contactless on and off operations, quickly selecting the appropriate voltage regulation position and transformer winding connection method. Its response time can reach milliseconds, ensuring uninterrupted and jump-free voltage regulation.

[0066] The thyristor switching module first parses the received control frame or signal instruction packet. Each instruction typically contains the following fields: Operation type (shift / maintain current state / disconnect / bypass switching); Phase (A, B, C, or all three phases); Gear number or target winding combination (e.g., "3rd gear," "Boost gear + compensation winding"); Execution timestamp or synchronization mark (for multiphase coordination); Redundancy checksum (redundancy checksum) to ensure communication data integrity. The module's built-in parsing logic decomposes these fields into local variables for subsequent control flow.

[0067] Before actual execution, the module must first read the current thyristor triggering state and transformer winding connection configuration. It compares the current state with the target state to determine whether a switchover is necessary. If the current gear position matches the target gear position, or the winding connection configuration is consistent, no action is required and the "state hold" feedback is displayed. If there is a discrepancy, the module enters the switchover preparation phase to prevent mis-switching and repeated switching. This process relies on local state caching and feedback mechanisms (such as Hall effect sensors detecting winding connection status or thyristor conduction signal confirmation) to ensure that switching is only performed when necessary, avoiding redundant actions and losses.

[0068] To achieve seamless, impact-free voltage switching, the thyristors (SCRs) must be precisely triggered to turn on or off at the voltage or current zero crossing. The module achieves precise control through the following logic: It samples the three-phase voltage waveforms in real time and calculates the estimated arrival time of the next zero crossing. If the voltage zero-crossing trigger mode is in operation, it searches for the positive or negative zero crossing moment. If the current zero-crossing trigger mode is in operation (suitable for load-switching-sensitive scenarios), it determines the turn-on / turn-off point based on the current waveform. An internal high-speed timer counts down to the target zero crossing point and precisely issues a trigger pulse signal. This trigger signal is then applied to the corresponding SCR gate via the driver circuit to turn it on or off. To achieve synchronous three-phase switching, a synchronous trigger flag can be set to ensure that the three-phase SCRs complete switching at the same relative moment, maintaining three-phase voltage consistency.

[0069] After the trigger pulse is output, the corresponding thyristor array in the module (usually a thyristor or bidirectional thyristor, with multiple parallel channels to handle large currents) immediately performs on-off control to re-establish the connection relationship between the transformer main winding and the compensation winding. Specific implementations include: disconnecting the winding path in the current connection state; turning on the target winding node according to the control logic; if the target state requires combining multiple windings or using a cross-connection method, turning them on one by one in the preset topological order to prevent short circuits or overvoltages; all on-off processes are completed in a contactless manner to avoid mechanical contact wear and contact jitter. The module is equipped with short-circuit detection and anti-parallel protection circuits, which automatically block the output and issue an alarm when any conduction path is abnormal (such as open circuit, breakdown, reverse surge).

[0070] After the switch is complete, the module enters the status confirmation phase to ensure that the voltage regulation operation is effective and stable. This phase involves rereading the voltage across the winding through the sampling circuit to confirm the corresponding voltage regulation level. The module then checks the consistency of the thyristor conduction state (confirmed by gate current or anode voltage). If it matches the expected state, a "switching complete" signal is fed back to the intelligent control unit. If an abnormal state exists (such as unchanged voltage or conduction failure), an error code is fed back and a backup strategy (such as repeated attempts or switching to bypass) is implemented.

[0071] The local state cache and feedback mechanism is used to read the current conduction state of the thyristor array and the connection configuration of the transformer winding, and compare them with the target state issued by the intelligent control unit: if the current state is consistent with the target state, a "state hold" feedback signal is output; if there is a difference, the switching preparation stage is entered to avoid repeated operations; the voltage or current zero-crossing point prediction logic is used to sample the three-phase voltage or current waveform in real time and calculate the expected arrival time of the next zero-crossing point. The zero-crossing point prediction includes: performing zero-crossing detection processing on the sampled signal (such as determining the sign change point from negative to positive); estimating the future zero-point arrival time by combining the sampling period and waveform frequency; setting the internal timer to delay the trigger to the target zero-crossing point; outputting a trigger pulse to the thyristor gate at the target zero-crossing point to achieve non-disruptive conduction or disconnection operation; if a "synchronous trigger mark" is set in the control instruction, the three-phase thyristors are synchronously triggered at the same relative time; The thyristor array control unit includes a thyristor array composed of multiple thyristors or bidirectional thyristors, which are used to construct different winding tap combination paths. The specific control logic is as follows: after receiving the voltage regulation control command, the current conduction path is disconnected; then the target channel is sequentially turned on according to the target voltage regulation gear or winding combination information; if the target configuration requires multiple winding combinations or a cross-connection structure, each segment switch is gradually turned on in a preset order to ensure that short circuits, breakdowns or surges are avoided; all conductions during the switching process are based on zero-crossing triggering, without mechanical contact jitter, achieving fast and jump-free switching; The standardized control instruction parsing unit is used to receive the standardized control instructions issued by the intelligent control unit. The instructions include the following fields: operation type field (such as gear adjustment, hold, bypass switching, etc.); operation phase field (A, B, C or three-phase); target voltage adjustment gear number or winding combination identifier; synchronization trigger flag, used to indicate whether three-phase synchronization triggering is required; check code field, used to ensure data integrity. The following is an example: State comparison logic example: The current conduction state of the thyristor array is phase A 3rd gear, phase B 3rd gear, phase C 3rd gear; the control unit issues a command target state of phase A 5th gear, phase B 3rd gear, phase C 3rd gear; the comparison finds that phase A is inconsistent → it is determined that switching is required, and only phase A enters the "switching preparation stage".

[0072] Zero-crossing prediction and trigger logic: The sampling frequency is 10kHz (i.e., sampling every 0.1ms). The current detected voltage of phase A is alternating between positive and negative and close to zero. The crossing point time t_0≈5.3ms (relative to the start of the current cycle) is calculated based on the previous and next sampling values. The trigger delay Δt=0.1ms is set, and the internal timer is set to output the trigger pulse after 5.4ms. When the set time is reached, the phase A thyristor is triggered and turned on, completing the upshift switch.

[0073] Example of winding combination path control logic: The control target is the series boost path of the combined winding R1+R3+R5. Control flow: First disconnect the original path → follow the preset sequence: turn on R1 → delay verification → turn on R3 → turn on R5. All turn-on instructions are triggered when the voltage in each path crosses zero to avoid surges.

[0074] During continuous operation, the module monitors the following parameters in real time: the conduction current and voltage of each thyristor; circuit temperature rise and thyristor junction temperature (to prevent thermal breakdown); operating frequency (to prevent fatigue failure caused by frequent gear changes); and logical anomalies such as drive pulse loss or false triggering. If any abnormal metric is detected outside the set range, the module immediately enters protection mode, prohibiting triggering, cutting off control pulses, and simultaneously sending a fault flag to the upper control unit.

[0075] The thyristor switching module, with a high-precision synchronous triggering mechanism at its core, combines multi-channel contactless conduction control, winding combination identification, zero-crossing triggering, and status confirmation feedback to achieve fast, smooth, and reliable voltage regulation range switching. Its control accuracy reaches milliseconds, fully adapting to dynamic voltage fluctuations and providing solid support for the stability and responsiveness of the entire intelligent voltage regulation system. This module not only handles a wide range of voltage regulation but also offers the advantages of anti-interference, long life, and low maintenance for engineering applications.

[0076] 5) The transformer module realizes basic voltage conversion under the guidance of thyristor switching, while the voltage regulation and compensation module further implements fine-tuning compensation based on the main transformer output to ensure that the output voltage is strictly controlled within ±2%, meeting the stable output requirements of 380V or 220V.

[0077] After the thyristor module selects and connects the target winding configuration, the transformer module performs a voltage conversion based on the winding tap position or series / parallel combination.

[0078] The transformer module uses a multi-tap autotransformer or multiple controllable windings, achieving multi-step voltage regulation through different winding combinations. For example, the difference between each tap set is set to 5V or 10V. Combined with step-up or step-down connections, it can cover a wide range of input voltage deviations of ±20% or even wider.

[0079] The intelligent control unit has already calculated the target gear number based on the deviation in the previous stage. The transformer module only needs to connect the corresponding winding according to the control signal. The connection path and conduction timing between the different gears are completed by the thyristor switching module. The transformer module begins stable operation as a passive power conversion unit. The transformer module outputs a coarse adjustment voltage with an accuracy of approximately ±5V, but it is difficult to achieve higher-precision real-time compensation. Therefore, a subsequent compensation module is required to achieve closed-loop correction.

[0080] Voltage regulation compensation modules typically utilize precision voltage-regulating transformers, magnetic amplifiers, bidirectional thyristor-controlled series compensation circuits, or electronic regulation circuits based on controlled rectifier bridges. Their function is to apply a small, continuously adjustable additional voltage to the main transformer output to achieve closed-loop fine-tuning of the output voltage. The compensation module uses the main transformer output as its input reference and, combined with the target deviation value fed back by the intelligent control unit, determines the compensation direction and magnitude in real time. The processing logic is as follows: Compensation direction judgment: If the output voltage of the main transformer is slightly lower than the target value, a forward compensation voltage is output and added in series to the load side; if it is slightly higher, a reverse compensation voltage is output; Compensation amplitude calculation: Divide the deviation value by the rated adjustment range of the compensation module to obtain the normalized compensation coefficient (for example, if the deviation is 2V and the module adjustment range is ±20V, the coefficient is ±10%). The compensation coefficient is used to set the thyristor conduction angle, PWM duty cycle or analog voltage output value to achieve continuously adjustable control.

[0081] The compensation module's output voltage is added directly to the main transformer voltage in series, forming the total output voltage. The key is that the voltage phase and polarity must match the main transformer output; otherwise, cancellation or even resonance may occur. The module features internal voltage polarity detection and automatic reverse polarity control to ensure that the compensation direction remains consistent with the main circuit output, regardless of whether it is positive or negative.

[0082] The voltage regulation compensation module does not stop running after a single action is completed, but continuously adjusts dynamically according to the output voltage status to form a closed-loop feedback mechanism. The specific processing logic is as follows: The output voltage is collected in real time (using high-frequency sampling and sliding window smoothing). The current value is compared with the target set value to obtain the secondary deviation. If the deviation is still within ±1% but not zero, a compensation adjustment is performed at a smaller amplitude (the fine-tuning step does not exceed ±0.5V). For example: the main transformer output is 377.5V, the target is 380V, the compensation module currently outputs +2V, and the total output is 379.5V, which is still 0.5V low. Continue to fine-tune the compensation to +2.5V, and eventually approach the target point of 380V.

[0083] To prevent overcompensation caused by miscontrol or grid interference, the voltage regulation compensation module has built-in protection and limiting logic: if the actual output voltage exceeds the set target by ±2% (for example, 220V exceeds 224.5V or is lower than 215.5V), the compensation output amplitude is immediately limited. When the compensation module output voltage approaches its full load capacity (for example, ±20V), the early warning mechanism is activated, requesting the superior to recalculate the main transmission gear position to avoid relying solely on compensation for large adjustments. At the same time, the module temperature rise and current load status are monitored to prevent thermal runaway or component loss caused by long-term high-power compensation.

[0084] The compensation module operates independently of the main transformer's conversion. Within the overall voltage regulation control, the compensation module's actions are subject to the main transformer's conversion results and are processed according to the following priority: When the main transformer's compensation can cover the current deviation range, the compensation module automatically deactivates and enters a standby state. If the main transformer cannot make further adjustments or responds slowly, the compensation module takes over control and performs rapid temporary adjustments. After the main transformer operation is completed, the compensation module continues to maintain closed-loop fine-tuning to ensure that the final output voltage is accurately and stably maintained within ±2%.

[0085] The transformer module is responsible for large-scale, discrete voltage conversion and serves as the "main regulator" in voltage regulation. The voltage compensation module, on the other hand, acts as the "fine-tuner," providing continuously adjustable, fast-responding, and dynamically corrected compensation voltage. The combination of these two components creates a hierarchical voltage regulation architecture. While ensuring wide-range voltage regulation capabilities, it also achieves high-precision, fast-responding voltage regulation. Ultimately, this ensures long-term output voltage stability within the specified range, meeting the stringent power quality requirements of critical equipment.

[0086] 6) If only one of the three phases has an abnormality, the control can identify the specific unbalanced phase and call the voltage regulation compensation module to perform independent voltage regulation on that phase only, without adjusting the three phases as a whole, accurately dealing with the three-phase voltage imbalance problem. In each sampling cycle, real-time comparison and deviation analysis will be performed based on the RMS value of the three-phase voltage. The specific processing logic is as follows: First, the effective value of each phase voltage is recorded separately, recorded as U_A, U_B, and U_C; then the average value of the three-phase voltage, U_avg, is calculated; then the relative deviation rate of each phase from the average value is calculated, recorded as: Deviation rate_A=(U_A-U_avg) / U_avg; Deviation rate_B=(U_B-U_avg) / U_avg; Deviation rate_C=(U_C-U_avg) / U_avg; An acceptable voltage deviation threshold range (e.g., ±5%) is set. If the deviation rate of only one phase exceeds this range, a single-phase abnormality is identified and the phase identity (e.g., low voltage on phase C) is recorded. This process uses floating-point comparison accuracy, rather than simple hard limits, to avoid misjudgments due to fluctuations. All calculations are performed within a fixed sliding window (e.g., 200 sampling points) to filter out transient jitter interference.

[0087] After identifying an unbalanced phase, further consideration is required to determine whether independent voltage regulation should be enabled. This determination involves determining whether the main transformer is currently in optimal gear, preventing further voltage increases or decreases; whether the other two phases are in good condition (no overvoltage or undervoltage); and whether the abnormality is a transient fluctuation (which requires exceeding the threshold for at least two consecutive cycles to trigger independent voltage regulation). If all of these conditions are met, the control unit activates the independent voltage regulation strategy, employing the compensation module for targeted regulation of only the abnormal phase.

[0088] When independent voltage regulation mode is enabled, voltage regulation compensation is calculated only for the unbalanced phase. This calculation is as follows: Let the target voltage be U_ref (e.g., 220V or 380V) and the measured voltage on the current unbalanced phase be U_x. The required compensation voltage is ΔU = U_ref - U_x. The compensation amount is typically mapped as a ratio of the controllable output voltage or a PWM modulation coefficient. For example, for a ±20V compensation range, the compensation coefficient is ΔU / 20V. This coefficient is passed to the voltage regulation compensation module along with a phase control flag to ensure synchronization of the output with the regulated phase voltage. For example, if the measured voltage on phase C is 207V and the target is 220V, and ΔU = +13V, the compensation coefficient is +65%. The compensation module then applies a +13V positive voltage to the output of phase C.

[0089] Upon receiving an independent voltage regulation command, the compensation module activates the compensation loop in the corresponding phase channel and performs single-phase voltage regulation. The process steps are as follows: The power regulation loop dedicated to that phase (such as a thyristor bridge circuit or PWM linear output module) is activated; the compensation voltage output is controlled to have the same frequency and polarity as the main transformer output; the output is connected in series with the main transformer to the power path of that phase to achieve overall voltage correction; and real-time feedback sampling of the phase voltage is maintained to achieve closed-loop tracking and regulation to avoid overshoot. The compensation module operates only on the target phase, while the other two phases remain in their current states, achieving true local phase closed-loop control.

[0090] Independent voltage regulation is not a one-time process, but rather a continuous feedback-based adjustment process. After voltage regulation is executed, the control module continues to monitor the voltage of that phase. If the compensated voltage returns to the set range and remains stable for multiple cycles, the voltage regulation is considered successful. If the imbalance persists, or if other phases begin to deviate due to external interference, the overall three-phase status is reassessed to determine whether to switch from "independent voltage regulation" to "all-phase voltage regulation" mode. If voltage regulation fails (e.g., reaching the compensation limit and not recovering), a request is sent to the main control module to re-switch the main transformer gear or enter the bypass protection process.

[0091] To prevent voltage instability or equipment overheating caused by single-phase regulation, the following protection mechanisms are activated during independent voltage regulation: If the compensation voltage output exceeds a certain time threshold (e.g., 30 seconds) and the load current is high, the compensation output power is reduced to reduce the temperature. If the three-phase voltage deviation shows an increasing trend, independent voltage regulation is interrupted and global regulation logic is implemented. If the compensation module detects an anomaly (such as uncontrolled conduction or component overtemperature), the compensation output for that phase is immediately cut off and the fault status is reported. To ensure that independent voltage regulation does not affect overall power supply stability, the compensation module's response priority is based on overall stability, while local stability is prioritized.

[0092] Through the above process, the problem phase can be quickly and accurately located as soon as a phase voltage anomaly is identified, and the voltage regulation and compensation module can be invoked to perform targeted regulation without interfering with other normal phases. This mechanism significantly improves the adaptability of three-phase voltage regulation to complex operating conditions such as asymmetric loads and single-phase fluctuations, achieving precise, efficient, and reliable voltage control and enhancing overall intelligence and robustness.

[0093] 7) After the grid voltage returns to stability and continues to meet the set time conditions, the intelligent control unit determines that the line voltage has entered a stable state and automatically sends a switching instruction to the thyristor switching module to guide the equipment into intelligent sleep mode: the voltage regulation related modules (main transformer, compensation transformer, thyristor) exit operation, the load is directly powered by the bypass, and only the information collection part is retained for continuous monitoring, minimizing equipment energy consumption and component wear.

[0094] The intelligent control unit evaluates the three-phase voltage status in each sampling cycle. If the voltage remains within the ± stability tolerance range (for example, ±1% to 2%) for a number of consecutive cycles (such as 10 seconds or a custom set duration), the stability judgment mechanism will be activated. Judgment logic: The effective value of each phase is recorded and compared with the target reference value (such as 380V or 220V); if the deviation of all phases is less than the set "sleep determination threshold", it is recorded as an "effective stable state"; within the set time window (such as 10 seconds), the time period that continuously meets the above conditions is accumulated; using a sliding time window mechanism, even if there are small fluctuations in the middle, it is still possible to determine whether the trend is stable; if the total timing is greater than the set threshold (such as 10 seconds of continuous stability), it is determined that the voltage has "entered a stable state."

[0095] This determination process incorporates hysteresis logic to prevent false triggering of sleep due to short-term stability. For example, the sleep entry condition is a ±2% error for 10 seconds, while the exit condition is a ±1% error with a momentary fluctuation to resume normal operation.

[0096] After confirming voltage stability, the device doesn't immediately enter sleep mode. Instead, it performs multiple checks to ensure that safe transition conditions are met: Check if no voltage regulation is currently in progress (to ensure steady state); if the thyristor module is in a stable on / off state and not switching; if the compensation module output has returned to zero (to confirm no residual compensation signal); if the load is stable and has no sudden changes (sleep is prohibited if the load current fluctuates significantly); if the device's internal temperature is within a safe range (to prevent thermal breakdown caused by power outages at high temperatures); and if no abnormality flags are currently active (including overvoltage, undervoltage, communication anomalies, overcurrent, etc.). If all of these checks pass, the device is safe to enter sleep mode.

[0097] After confirming that it is possible to enter sleep mode, the intelligent control unit will generate a sleep switching instruction packet and send it to the thyristor switching module through the control bus. The instruction contains: Command type: exit voltage regulation, switch to bypass; Action sequence: first open the bypass, then open the voltage regulation circuit; Delay or synchronization control flag: control the timing of each action to prevent instantaneous fluctuations caused by power outages.

[0098] The execution logic is as follows: The control module first turns on the bypass circuit, allowing the input power to be supplied directly to the load end through the bypass. After confirming that the bypass conduction is stable (which can be confirmed by voltage detection or the status of the bypass relay), it then executes the action of disconnecting the voltage regulation path, including shutting down the main transformer output path, shutting down the compensation module excitation, and disconnecting the thyristor gate drive. All shutdown operations must be triggered at zero voltage or zero current to prevent arcing, current surges, or output jumps during the shutdown process. After completing the above actions, the current state is marked as "sleep mode". In the sleep state, the power supply and control of the following modules are automatically shut down: the main transformer winding excitation circuit (if it is a magnetic control type); the compensation module rectifier bridge and control drive; the thyristor gate drive unit and redundant protection circuit; high-speed communication and control tasks are suspended, and some voltage regulation calculation tasks are suspended; only the following minimum units are kept running: Information acquisition and processing unit: Continues to monitor key parameters such as input voltage, current, and frequency; in sleep mode, total power consumption can be reduced to 10% to 20% of normal operating power consumption, and is only used for monitoring and standby control.

[0099] The input voltage is continuously monitored during sleep mode. The system automatically exits sleep mode and re-enters voltage regulation mode if any of the following conditions are detected: any phase voltage exceeds the set tolerance (e.g., ±2%); three-phase imbalance exceeds a threshold (e.g., any phase deviates by more than ±5%); input frequency fluctuates; load current suddenly changes (indicating a change in load status); or a periodic forced wake-up detection point is triggered (e.g., automatically re-evaluating the status every 10 minutes). The wake-up process is the opposite of the sleep process, with the bypass disconnected before the main transformer and compensation module resume operation according to the set status, and the voltage regulation closed loop is re-established.

[0100] Intelligent sleep mode achieves efficient energy control for voltage regulation through continuous assessment of voltage stability, multi-condition safety review, non-disruptive bypass switching, and optimized power consumption management. Its core advantage lies in automatically disconnecting high-energy-consuming modules when voltage conditions are favorable, preventing energy waste and component aging caused by the continuous operation of equipment such as the main transformer, thyristors, and compensators, while ensuring uninterrupted power supply to the load. The introduction of sleep mode enables intelligent voltage regulation to not only provide voltage regulation capabilities but also incorporate intelligent operating strategies and adaptive energy-saving features, making it a key advanced feature in smart power equipment.

[0101] 8) During operation, if abnormal conditions such as input overvoltage / undervoltage, output abnormality, overcurrent, or equipment failure are detected, the intelligent control unit will immediately instruct the bypass to start operation, so that the load can be seamlessly switched to the direct power supply path, protecting the terminal equipment and avoiding power interruption. At the same time, the fault information will be fed back to the host computer or remote monitoring to facilitate rapid response by maintenance personnel. Key parameters are continuously sampled in real time at high frequency, including: three-phase input voltage (for identifying overvoltage / undervoltage), output voltage (for identifying voltage regulation failure or abnormal fluctuation), output current (for identifying overload or short circuit), internal temperature, power status, communication status, thyristor feedback signal and other equipment operating parameters. The processing logic is as follows: 8.1 Input overvoltage / undervoltage judgment Compare each phase voltage with the rated reference value (such as 380V); If any phase voltage exceeds ± set tolerance (e.g. ±20%); And it continues to exceed the set response delay (such as 100ms); The input voltage is determined to be abnormal and the protection state is triggered.

[0102] 8.2 Output voltage abnormality determination The output voltage is continuously sampled to calculate the effective value and fluctuation rate; If the voltage regulator module is in regulation, but the output voltage cannot return to the ±2% range; Or there may be atypical fluctuations such as waveform distortion and jumps; It is determined to be a voltage regulation failure or output abnormality.

[0103] 8.3 Overcurrent Identification Logic The output current is greater than the maximum rated value (e.g., 110% to 130% of the rated current); If it is instantaneous overcurrent, record the number of times; If the continuous duration threshold (such as 300ms~500ms) is exceeded, the overcurrent protection mode is entered.

[0104] 8.4 Self-fault detection The thyristor fails to conduct and the feedback is lost; Abnormal temperature rise (e.g. internal radiator temperature exceeds 90°C); Communication anomalies (such as CPU watchdog timeout, control instruction execution failure); The power supply is unstable or the bypass is not responding.

[0105] As long as any one of the items triggers an abnormal judgment, the control immediately enters the protection response process.

[0106] Exception types have priority judgment logic: Severe abnormalities (extreme input voltage exceeding the limit, severe output instability, equipment hard failure): switch to bypass immediately; medium-level abnormalities (instantaneous overcurrent, fluctuation within the limit): allow a short wait for self-recovery; when the abnormality is not confirmed to be a stable trend (such as boundary fluctuation): perform soft monitoring and continue observation; once it is determined that bypass intervention is required, the control will prioritize the bypass conduction action.

[0107] The control unit immediately generates a bypass switching instruction, and the main control process is as follows: the instruction structure includes a bypass conduction signal, a voltage regulation path disconnection signal, and a switching status mark; the action sequence is to first turn on the bypass → check for stability → then disconnect the voltage regulation path; all switches must be triggered based on zero voltage or current zero crossing to ensure no impact jump; the bypass path is generally a magnetic latching relay or a solid-state bypass device (such as a relay thyristor parallel path), which can complete the on-off operation within 20ms~50ms.

[0108] Immediately after the switch is completed, verify: whether the output voltage is stable and maintained (confirm that the bypass is normally connected); whether the output current is continuously supplied (ensure that the load is not powered off); if the switch fails (such as bypass abnormality), enter the secondary protection strategy: such as emergency disconnection of the output, sending a hardware alarm, etc.

[0109] After a fault occurs, the control will automatically complete the following operations: structured recording of abnormal data: including timestamp, abnormality type, snapshots of various electrical parameters, response time, bypass switching status, etc.; encapsulating the information into a fault event frame and uploading it to the host computer or remote monitoring platform, supporting communication protocols such as MODBUS, CAN, RS485, MQTT, etc.; if local storage (EEPROM or SD card) is available, it will be recorded in the fault log area for subsequent analysis and tracing; if a cloud platform is supported, the data will be sent to the operation and maintenance center in real time via the edge gateway to generate maintenance work orders or notify the on-duty personnel.

[0110] After switching to bypass mode, the system enters the bypass power supply state, but does not exit the monitoring work. The main logic is as follows: continue to monitor the input / output voltage, current and other electrical parameters to determine whether the voltage has recovered; monitor whether the fault itself has been resolved (such as temperature drop, communication recovery); if it is detected that it has recovered to stability, it can enter the "wake-up state"; if the automatic recovery mode is configured, it will try to disconnect the bypass first, and then restore the voltage regulation module in turn; if it is in manual reset mode, it will only issue a recovery prompt and wait for the operation and maintenance personnel to intervene.

[0111] This exception handling and bypass switching mechanism establishes a highly intelligent, responsive, and comprehensive emergency logic chain. It not only enables uninterrupted switching to the direct power supply path within milliseconds, maximizing load continuity, but also fully records and uploads abnormal events, providing a precise basis for subsequent operations and maintenance. Through technologies such as redundant logic, zero-jump switching, closed-loop feedback, and event tracking, it achieves a multi-dimensional response to abnormalities in the power grid, voltage quality, and the device's own status, making it an indispensable safety mechanism for modern intelligent voltage stabilization.

[0112] Throughout this specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0113] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the present invention to specific embodiments. Obviously, many modifications and variations are possible based on the contents of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. Low voltage line intelligent voltage regulator control system, characterized by: It includes information acquisition and processing unit, intelligent control unit, thyristor switching module, voltage transformation module and voltage regulation compensation module; The information collection and processing unit is used to collect and process the electrical parameters of the three-phase input line in real time after the equipment is powered on; The intelligent control unit determines whether the current line voltage needs voltage regulation based on the control algorithm, and if so, generates the corresponding voltage regulation control instruction; The thyristor switching module performs contactless on and off operations to switch the corresponding voltage regulation gear and control the winding connection mode of the transformer module; A voltage conversion module, used to complete voltage conversion under the control of the thyristor switching module; A voltage regulating and compensating module is used to perform voltage compensation based on the voltage conversion of the transformer module, so that the output voltage is controlled within a preset range; Wherein, when a phase voltage is abnormal, the intelligent control unit independently adjusts the phase voltage regulation compensation module; When it is detected that the grid voltage has recovered and stabilized within a set time, the intelligent control unit controls the thyristor switching module to stop the main voltage regulation circuit from running, switch to bypass power supply and enter sleep mode; When an abnormality is detected, the intelligent control unit automatically switches to bypass operation.

2. The low-voltage line intelligent voltage regulator control system according to claim 1, characterized in that: The intelligent control unit is embedded with an intelligent judgment and control algorithm, which includes voltage state judgment logic, three-phase imbalance recognition logic, voltage regulation decision logic, sleep judgment logic and abnormal protection logic.

3. The low-voltage line intelligent voltage regulator control system according to claim 2, characterized in that: The voltage state judgment logic is based on the comparison of the three-phase voltage effective value with the preset reference voltage, and uses the floating tolerance interval judgment method to determine the voltage state, which is divided into overvoltage zone, undervoltage zone and stable zone; The three-phase imbalance identification logic calculates the average value of the three-phase voltage and calculates the relative deviation rate between each phase and the average value. If the deviation rate of any phase exceeds the deviation rate threshold, it is marked as a voltage imbalance state and the unbalanced phase is identified.

4. The low-voltage line intelligent voltage regulator control system according to claim 3, characterized in that: After identifying voltage deviation or imbalance, the voltage regulation decision logic generates a voltage regulation control instruction based on a control algorithm. The control algorithm includes a fuzzy mapping rule based on error and rate of change, generates the voltage regulation direction, voltage regulation phase and voltage regulation amount through error calculation and dynamic weight control, and constructs a data packet containing the voltage regulation instruction type, execution priority and output control amount.

5. The low-voltage line intelligent voltage regulator control system according to claim 4, characterized in that: The sleep determination logic is used to monitor whether the voltage is stable within a set range during multiple consecutive sampling periods, and whether the fluctuation amplitude is less than a preset fine-tuning threshold, and if there is no overcurrent or imbalance state, it is automatically determined to be a sleep candidate state and output a sleep control instruction; The abnormal protection logic is used to automatically generate a bypass switching instruction when it detects that the input voltage exceeds the limit, the output voltage cannot return to stability, there is overcurrent, or a system component failure.

6. The low-voltage line intelligent voltage regulator control system according to claim 1, characterized in that: The thyristor switching module reads the current thyristor conduction state and transformer winding connection information through the local state cache and feedback mechanism, and outputs a state holding signal if the current state is consistent with the target state; If there is a difference, the switching preparation phase begins; By real-time sampling of the three-phase voltage or current waveform, predicting the arrival time of the next zero-crossing point, and controlling the internal timer based on the target trigger type, the thyristor trigger pulse signal is output at the predetermined time point for disturbance-free conduction and disconnection. If a synchronous trigger mark is provided, the three-phase thyristors are controlled to complete switching at the same relative moment.

7. The low-voltage line intelligent voltage regulator and voltage stabilizer control system according to claim 6, characterized in that: The thyristor switching module includes a thyristor array control unit, which includes multiple thyristor or bidirectional thyristor branches for constructing a winding tap combination path. After receiving a trigger signal, it disconnects the current path and turns on the target winding channel according to the control logic. If the target configuration includes multiple windings or a cross connection, it is gradually turned on in a preset order.

8. The low-voltage line intelligent voltage regulator and voltage stabilizer control system according to claim 7, characterized in that: The control instruction includes an operation type, an operation phase, a target voltage regulation gear or a winding combination, a synchronization mark and a check code.

9. The low-voltage line intelligent voltage regulator and voltage stabilizer control system according to claim 1, characterized in that: The information acquisition and processing unit acquires voltage and current analog signals of the three-phase input line; The collected signal enters the analog low-pass filter circuit to filter out high-frequency noise and harmonic interference, and the filtered signal is input to the analog-to-digital converter; The digital signal after analog-to-digital conversion undergoes zero offset correction and gain correction and is converted into voltage and current values; The information acquisition and processing unit performs real-time electrical parameter characteristic calculation on each phase; Various electrical parameter characteristics are combined into structured data packets, including three-phase voltage, current effective value, frequency, phase difference, voltage balance and status flags.

10. The low-voltage line intelligent voltage regulator and voltage stabilizer control system according to claim 9, characterized in that: The information acquisition and processing unit performs real-time electrical parameter characteristic calculation on each phase, including the following steps: Calculate the effective value of each phase voltage and current through the sliding window algorithm; Based on the zero-crossing point detection of the voltage waveform, the cycle length between two consecutive positive zero-crossing points is obtained, and the current frequency is calculated based on its reciprocal; The power factor is estimated by calculating the phase difference between the main frequency sinusoidal components of the voltage and current signals; Compare the three-phase voltage RMS values ​​in real time and calculate the relative deviation rate from the average value to determine whether the three-phase voltage is unbalanced.

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