Method and device for controlling three-phase power dynamic optimization double-phase output

Abstract

The invention relates to the technical field of three-phase power dynamic optimization double-phase output control, in particular to a three-phase power dynamic optimization double-phase output control method and device. The method comprises the following steps: collecting line voltage and load current signals of a three-phase power supply; identifying the load type according to the characteristics of the load current signal; determining a health degree evaluation value of each line according to the load type and the harmonic distortion rate and the voltage fluctuation rate of each line voltage; selecting the line with the optimal health degree evaluation value as a selected line; if it is determined that the health degree evaluation value of the selected line meets a preset safety condition, outputting a two-phase voltage including the selected line; and if the preset safety condition is not met, synthesizing two-phase voltage through a bridge circuit and outputting the two-phase voltage.

Description

Technical Field

[0001] This application relates to the field of power conversion and control technology, and in particular to a control method and device for dynamic optimization of two-phase output in three-phase electricity. Background Technology

[0002] Three-phase AC power supply systems are core energy infrastructure for modern industry and commerce due to their high efficiency, high power transmission, and load balancing capabilities. Traditional management schemes focus on basic power transmission, voltage stability, and significant fault protection (such as overload and short circuit), relying on fixed connections and static assumptions (relatively stable power grid and slow load changes), and are robust and cost-effective in stable environments.

[0003] With the transformation of energy structure, the popularization of distributed power sources, and the rapid growth of nonlinear loads (such as frequency converters, LEDs, and data centers), power supply and demand and load characteristics have become highly complex and dynamic.

[0004] The traditional extensive control strategy has revealed its fundamental limitations: it lacks the ability to assess the subtle power quality of the power grid in real time and in a multi-dimensional manner, and cannot achieve accurate dynamic optimization switching. Therefore, it urgently needs to be improved. Summary of the Invention

[0005] Therefore, it is necessary to provide a control method and device for dynamically optimizing two-phase output of three-phase electricity to achieve precise switching, addressing the aforementioned technical problems.

[0006] In a first aspect, this application provides a control method for dynamically optimizing two-phase output in three-phase electricity, the method comprising: Acquire the line voltage and load current signals of the three-phase power supply; Identify the load type based on the characteristics of the load current signal; The health evaluation value of each line is determined based on the load type, the harmonic distortion rate of the voltage of each line, and the voltage fluctuation rate. Select the route with the best health rating as the chosen route; If the health evaluation value of the selected line is determined to meet the preset safety conditions, the output includes the two-phase voltage of the selected line. If the preset safety conditions are not met, a two-phase voltage output is synthesized through a bridge circuit.

[0007] In one embodiment, a health assessment value for each line is determined based on the load type, the harmonic distortion rate of the voltage per line, and the voltage fluctuation rate, including: Based on the load type, determine the harmonic distortion weight corresponding to the harmonic distortion rate and the voltage fluctuation weight corresponding to the voltage fluctuation rate; where, when the load type is a motor load, the voltage fluctuation weight is greater than the harmonic distortion weight; when the load type is a lighting load, the harmonic distortion weight is greater than the voltage fluctuation weight; when the load type is a general load, the harmonic distortion weight is equal to the voltage fluctuation weight. The health evaluation value of each line is determined based on the harmonic distortion rate, voltage fluctuation rate, harmonic distortion weight, and voltage fluctuation weight of each line voltage.

[0008] In one embodiment, a health assessment value for each line is determined based on the harmonic distortion rate, voltage fluctuation rate, harmonic distortion weight, and voltage fluctuation weight of each line voltage, including: When a load type switch is detected, the migration rate of harmonic distortion weight and voltage fluctuation weight is dynamically adjusted according to the load power change rate. During the migration of harmonic distortion weight and voltage fluctuation weight, a compensation factor positively correlated with transient current fluctuation is introduced to correct the health evaluation value. After the harmonic distortion weight and voltage fluctuation weight are migrated, the health evaluation value is calculated according to the fixed weight corresponding to the new load type.

[0009] In one embodiment, a health assessment value for each line is determined based on the harmonic distortion rate, voltage fluctuation rate, harmonic distortion weight, and voltage fluctuation weight of each line voltage, including: During the calculation of the health assessment value, environmental temperature and humidity parameters are simultaneously monitored. If the temperature and humidity parameters exceed the preset range, the health evaluation value will be reduced as compensation. When the health evaluation value after derating compensation triggers the operation of synthesizing two-phase voltage output through a bridge circuit, the circuit combination with the least impact from temperature and humidity is selected first.

[0010] In one embodiment, before determining that the health evaluation value of the selected line meets preset safety conditions, the method further includes: Monitor the load efficiency of the selected line; When the load efficiency remains below historical levels, the threshold of the preset safety condition will be dynamically lowered.

[0011] In one embodiment, after determining that the health evaluation value of the selected line meets the preset safety conditions, the method further includes: Based on the time-series change data of the health evaluation value corresponding to the selected route, predict the future deterioration trend of the health evaluation value corresponding to the selected route. If the future deterioration trend does not meet the early warning safety conditions, preparations for synthesizing two-phase voltage output through a bridge circuit should be initiated in advance. Among them, the safety requirements for early warning safety conditions are lower than those for preset safety conditions.

[0012] In one embodiment, after determining the selected line, the method further includes: Monitor the temperature of power devices in the selected circuit during operation; When the temperature of the power device exceeds the first threshold, the backup line combination with the best stability is selected based on the historical trend of the health evaluation value of each line. At the moment the voltage crosses zero, the selected line will be switched to the backup line combination.

[0013] In one embodiment, the optimal combination of backup lines with the best stability is selected based on the historical trend of the health evaluation value of each line, including: Based on the historical trend of the health evaluation value of each route, the switching path with the best electromagnetic compatibility is selected as the backup line combination with the best stability.

[0014] In one embodiment, the two-phase voltage output is synthesized via a bridge circuit, and the method further includes: When the temperature of the power device exceeds the second preset threshold, a multi-level topology is activated to disperse thermal stress; the second preset threshold is lower than the first threshold. After enabling the multilevel topology, switching tasks are preferentially assigned to the devices with the highest remaining lifetime based on the cumulative damage status of the power devices.

[0015] Secondly, this application provides a control device for dynamic optimization of two-phase output in three-phase electricity, the device comprising: The acquisition unit is used to acquire the line voltage and load current signals of the three-phase power supply. The identification unit is used to identify the load type based on the characteristics of the load current signal; The evaluation unit is used to determine the health evaluation value of each line based on the load type, harmonic distortion rate of the voltage per line, and voltage fluctuation rate. The selection unit is used to select the route with the best health rating as the selected route. The first output unit is used to output a two-phase voltage containing the selected line if the health evaluation value of the selected line meets the preset safety conditions. The second output unit is used to synthesize a two-phase voltage output through a bridge circuit if the preset safety conditions are not met.

[0016] The aforementioned three-phase dynamic optimization control method and device for two-phase output achieves multi-dimensional dynamic assessment of the power line health status by real-time acquisition and analysis of three-phase power quality parameters (harmonic distortion rate, voltage fluctuation rate) combined with load characteristics. Based on an intelligent optimization mechanism using health evaluation values, it directly outputs the optimal phase power when a single-phase line meets safety conditions, and actively synthesizes high-quality two-phase voltage output when health is insufficient. Ultimately, this effectively overcomes the shortcomings of traditional solutions in responding to minor power quality degradation and progressive faults with lag, significantly improving the system's adaptability to complex power grid environments and sensitive loads. It ensures continuous and high-quality power supply to critical loads while maximizing the utilization of available power resources, fundamentally improving power supply reliability and power quality. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a flowchart illustrating a control method for dynamically optimizing two-phase output in a three-phase power supply, as described in one embodiment. Figure 2 This is a structural block diagram of a three-phase power protection device in one embodiment; Figure 3 This is a circuit diagram of the data acquisition section in a three-phase power protection device in one embodiment; Figure 4 This is a circuit diagram of the power supply section in a three-phase power protection device in one embodiment; Figure 5 This is a circuit diagram of the control section in a three-phase electrical protection device in one embodiment. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0020] In one exemplary embodiment, such as Figure 1 As shown, a control method for dynamic optimization of two-phase output in three-phase electricity is characterized by comprising: S101 collects the line voltage and load current signals of the three-phase power supply.

[0021] In a three-phase power supply, the line voltage refers to the voltage between any two phases (e.g., the RS, ST, and TR voltages between the R, S, and T phases). It is a core parameter for measuring the power quality of three-phase electricity, with a typical value of 380V / 50Hz in industrial settings. The load current signal is the electrical signal generated by the current flowing through the electrical equipment (load). Its waveform characteristics (e.g., harmonic content, transient changes) reflect the electrical characteristics of the load (e.g., the peak current during motor startup, the smooth current waveform of lighting equipment). Optionally, a voltage sensor can be used to collect the line voltage, and a current sensor can be used to collect the load current signal.

[0022] S102 identifies the load type based on the characteristics of the load current signal.

[0023] The characteristics of the load current signal refer to the current parameters reflecting the electrical characteristics of the load, including steady-state characteristics (such as RMS value, peak factor, and total harmonic distortion) and transient characteristics (such as peak starting current, duration, and current sag rate). Load type: Classified according to the electrical characteristics of the electrical equipment, typical loads include motor loads (such as servo motors and induction motors), lighting loads (such as LED lights and fluorescent lamps), and general-purpose loads (such as resistance heating equipment and linear power supplies).

[0024] Optionally, the current waveform is analyzed every 100 milliseconds to extract steady-state features (RMS value, peak factor, power factor, THD_I, and 3rd / 5th / 7th harmonic content) and transient features (peak / duration of starting current, current sag rate). The feature parameters are input into a pre-trained machine learning model (such as DNN, SVM) or a rule-based expert system; the model is built by offline learning of typical load data, outputting load category identifiers (such as precision servo motor loads) and confidence scores (≥0.9 is considered reliable), and is periodically updated to adapt to dynamic load changes.

[0025] S103, determine the health evaluation value of each line based on the load type, harmonic distortion rate of each line voltage, and voltage fluctuation rate.

[0026] Among them, Harmonic Distortion Rate (THD(V)): The ratio of the effective value of each harmonic in the line voltage to the effective value of the fundamental voltage, reflecting the degree of voltage waveform distortion. Analyzed up to the 50th harmonic according to IEC 61000-4-7 standard, a typical value for a healthy power grid is ≤2.5%. Voltage Fluctuation Rate: The degree of change in the line voltage RMS value, including short-term change rate (maximum percentage change within 1 second) and long-term flicker index Pst (IEC 61000-4-15 standard, reflecting the perceived flicker of lights). Health Rating (H_line): A dimensionless index that integrates load type, THD(V), and voltage fluctuation rate; a higher value indicates better line power quality (range 0-1).

[0027] Optionally, THD(v) can be calculated using DFT, and the short-term voltage change rate and flicker index Pst can be calculated using a sliding window. Weights are determined based on load type (w1 is the harmonic distortion weight, w2 is the voltage fluctuation weight, w1+w2=1): for motor loads, w2>w1 (e.g., 0.7:0.3), for lighting loads, w1>w2 (e.g., 0.6:0.4), and for general loads, w1=w2 (0.5:0.5).

[0028] Furthermore, a weighted model is adopted:

[0029] in, , These are preset reference values ​​(e.g., 2.5% and 1.5% respectively). To avoid using a constant with an excessively small denominator (such as 0.01), the calculation is performed independently for each route. , and .

[0030] S104. Select the route with the best health rating as the selected route.

[0031] The optimal line refers to the line with the highest health rating among the current three-phase lines, whose power quality best meets the load requirements. The selected line is the line that, after comparison, is currently prioritized to supply power to the load.

[0032] Optionally, the health evaluation value of each line can be set at a preset period (e.g., once per second). , and Real-time comparison is performed, and the line with the highest value is selected as the chosen line. Anti-jitter mechanism: If the optimal line changes in adjacent cycles, a short delay (such as 500ms) can be set to reconfirm, avoiding frequent switching due to short-term fluctuations.

[0033] S105, determine whether the health evaluation value of the selected line meets the preset safety conditions; if yes, proceed to S106; otherwise, proceed to S107.

[0034] S106 outputs two-phase voltages for the selected line.

[0035] S107 synthesizes two-phase voltage output through a bridge circuit.

[0036] Among them, the preset safety conditions are: the minimum threshold of the system's preset health evaluation value (e.g., A value below this threshold indicates that the power quality of the line may not be able to guarantee stable operation of the load. The output includes the two-phase voltage of the selected line: the two-phase voltage of the selected line is directly connected to the load through a switching device to achieve power supply.

[0037] Optionally, the health evaluation value of the selected line can be compared with a preset safety threshold. If... If the condition is met, it is determined that the condition is met. (2) Voltage output switching device: adopt a high-reliability fast switching device (such as solid-state relay SSR, vacuum contactor), with zero voltage turn-off / zero current turn-on function, switching time ≤1ms, to avoid switching impact. Control logic: the microcontroller or DSP outputs control signal to drive the switching device to close, directly transmits the selected line voltage to the load input terminal, and at the same time, the output status is fed back through indicator lights.

[0038] Among them, the bridge circuit: a full-bridge or half-bridge topology circuit with power semiconductor devices (such as IGBTs and SiCMOSFETs) as its core, can convert DC or three-phase power into adjustable AC power. Synthesized two-phase voltage output: through pulse width modulation (PWM) control of the bridge circuit, a two-phase AC power with stable amplitude, frequency, and phase is generated to replace the original line voltage with poor power quality.

[0039] Optionally, the bridge circuit structure adopts a full-bridge inverter topology. The DC side consists of a rectifier (such as an active front-end PWM rectifier) ​​and an energy storage capacitor bank (such as a 450V / 5000μF thin-film capacitor), while the AC side consists of IGBT or SiCMOSFET modules, supporting high-frequency switching (such as 10kHz). Space vector pulse width modulation (SVPWM) or sinusoidal pulse width modulation (SPWM) algorithms are executed via DSP or FPGA to generate drive signals according to load requirements, control the switching of power devices, and synthesize a two-phase voltage with low harmonics (THD(V) ≤ 1.5%) and stable amplitude (±0.5% of rated value). The switching from the original line to the synthesized voltage is completed at the voltage zero-crossing point, or soft-start technology is used to ensure a shock-free switching process (voltage interruption ≤ 10ms).

[0040] In an exemplary embodiment, determining the health evaluation value of each line based on the load type, the harmonic distortion rate of each line voltage, and the voltage fluctuation rate includes: determining the harmonic distortion weight corresponding to the harmonic distortion rate and the voltage fluctuation weight corresponding to the voltage fluctuation rate based on the load type; and determining the health evaluation value of each line based on the harmonic distortion rate, voltage fluctuation rate, harmonic distortion weight, and voltage fluctuation weight of each line voltage.

[0041] Specifically, when the load type is a motor load, the voltage fluctuation weight is greater than the harmonic distortion weight; when the load type is a lighting load, the harmonic distortion weight is greater than the voltage fluctuation weight; and when the load type is a general load, the harmonic distortion weight is equal to the voltage fluctuation weight.

[0042] Optionally, based on the voltage fluctuation rate, harmonic distortion weight, and voltage fluctuation weight of each line, a health evaluation value for each line is determined, including: during the calculation of the health evaluation value, the ambient temperature and humidity parameters are detected simultaneously; if the temperature and humidity parameters exceed the preset range, the health evaluation value is derating; when the derating-compensated health evaluation value triggers the operation of synthesizing two-phase voltage output through a bridge circuit, the line combination with the least impact from temperature and humidity is selected first.

[0043] Understandably, load type refers to categories categorized based on the electrical characteristics of the equipment. Core categories include motor loads (such as servo motors and induction motors), lighting loads (such as LED lights and fluorescent lamps), and general-purpose loads (such as pure resistance heating equipment and linear power supplies). Harmonic Distortion Rate (THD(V)): The ratio of the square root of the sum of the squares of the effective values ​​of all harmonics in the line voltage to the effective value of the fundamental frequency, reflecting the degree of voltage waveform distortion (analyzed up to the 50th harmonic according to IEC 61000-4-7 standard). Voltage Fluctuation Rate: The degree of change in the root mean square (RMS) value of the line voltage, including short-term change rate (such as the maximum percentage change in RMS value within 1 second) and long-term fluctuation index (such as the flicker index Pst of IEC 61000-4-15 standard, used to assess the perceived flicker of lights). Harmonic Distortion Weight w1: A coefficient quantifying the impact of harmonic distortion rate on line health; a larger value indicates a more critical impact of harmonics on the current load. Voltage fluctuation weight w2: A coefficient that quantifies the impact of voltage fluctuation rate on line health. The larger the value, the more critical the impact of voltage fluctuation on the current load.

[0044] Optionally, harmonic distortion weight w1 and voltage fluctuation weight w2 are pre-stored in a lookup table in system memory, calibrated offline based on the characteristics of different load types, and the total weight is normalized to 1 (w1+w2=1). The corresponding weight is called according to the identified load type: Motor loads: Voltage fluctuation weight is greater than harmonic distortion weight (e.g., w2=0.7, w1=0.3), because motors are sensitive to sudden voltage rises / falls (e.g., easily leading to unstable speed and decreased positioning accuracy); Lighting loads: Harmonic distortion weight is greater than voltage fluctuation weight (e.g., w1=0.6, w2=0.4), because harmonics easily cause LED flickering or shortened lifespan; General loads: Harmonic distortion weight is equal to voltage fluctuation weight (e.g., w1=0.5, w2=0.5), indicating a balanced attention to both.

[0045] Furthermore, the health rating (H_line) is a dimensionless index that comprehensively reflects the power quality and health status of the line. The higher the value, the better the power quality of the line (usually ranging from 0 to 1).

[0046] It is understandable that the harmonic distortion rate (THD(v)) is calculated by performing a Discrete Fourier Transform (DFT) on the acquired line voltage waveform, separating the fundamental frequency from each harmonic, and then applying the formula (THD(v) = √(RMS value of each harmonic)). 2 (Sum of RMS values) / fundamental effective value); Voltage fluctuation rate: The short-term change rate of the voltage RMS value is calculated through a 1-second sliding window, and the flicker index Pst (reflecting the impact of long-term fluctuations on lighting) is calculated using statistical methods. The specific calculation process is as described in formula (1) above.

[0047] Among these parameters, environmental temperature and humidity parameters refer to the temperature and relative humidity of the power system's operating environment. Extreme temperatures and humidity (e.g., temperature > 50℃, humidity > 90%RH) accelerate equipment aging and affect line performance. Derating compensation: When temperature and humidity exceed safe ranges, a correction factor lowers the health evaluation value to reflect the negative impact of extreme environments on line reliability. Line combination with minimal impact from temperature and humidity: When synthesizing voltage output, priority is given to line combinations less affected by current temperature and humidity (e.g., low power device efficiency degradation, low thermal stress).

[0048] Optionally, high-precision digital temperature and humidity sensors are placed inside the cabinet and near the power components, collecting data every second and transmitting it to the DSP / MCU via I2C bus. If the temperature or humidity exceeds the preset safety range, a derating factor is mapped using a non-linear function. For example, when the temperature exceeds the limit: When humidity exceeds the limit: The final health rating is revised as follows: When the compensated health level triggers the synthesized output, the pre-stored line combination performance degradation model (based on experiments / simulations) is queried, and the line combination with the lowest efficiency degradation and lowest thermal stress under the current temperature and humidity is selected first (e.g., RS combination is better than RT combination).

[0049] Furthermore, based on the harmonic distortion rate, voltage fluctuation rate, harmonic distortion weight, and voltage fluctuation weight of each line voltage, the health evaluation value of each line is determined, including: when a load type change is detected, dynamically adjusting the migration rate of the harmonic distortion weight and voltage fluctuation weight according to the load power change rate; during the migration of the harmonic distortion weight and voltage fluctuation weight, introducing a compensation factor positively correlated with transient current fluctuation to correct the health evaluation value; after the migration of the harmonic distortion weight and voltage fluctuation weight is completed, calculating the health evaluation value according to the fixed weight corresponding to the new load type.

[0050] Among them, load type switching refers to the change of load category from one type to another (e.g., from general type to motor type), which is usually accompanied by significant changes in electrical characteristics. Load power change rate (dP / dt): The rate of change of instantaneous load power (calculated as (current power - previous power) / time interval Δt), reflecting the severity of the switching. Weight migration rate: The speed at which weights transition from the old load type preset value to the new load type preset value, dynamically adjusted by the power change rate. Transient current fluctuation: Short-term irregular changes in current that occur during load switching (e.g., motor starting inrush current), quantified by the standard deviation of the high-frequency components of the current. Compensation factor (C_transient): A penalty term positively correlated with transient current fluctuation, used to correct the health evaluation value during the migration process.

[0051] Optionally, the load type identifier is monitored in real time. When a switch occurs, the instantaneous power (P_inst = voltage RMS × current RMS × power factor) is calculated based on the voltage and current signals, and then the power change rate (dP / dt) is calculated, with Δt typically set to 10 milliseconds. The migration speed is set according to the power change rate: for sudden power changes (e.g., changes >20% within 50 milliseconds): fast migration is used (smoothing coefficient = 0.25, convergence within 200 milliseconds); for gradual power changes (e.g., changes <5% within 50 milliseconds): slow migration is used (smoothing coefficient = 0.05, convergence within 1 second); a weighted moving average is used to achieve a smooth transition of weights and avoid abrupt changes.

[0052] During the migration process, the transient component of the current signal is extracted by high-pass filtering (cutoff frequency 10Hz), and its standard deviation (σ_I) is calculated. The compensation factor is... The health formula is revised to the following formula (1): (1) When the weights converge stably to the preset value for the new load type (deviation <1% and lasting for 50 milliseconds), compensation stops, and the health evaluation value is calculated according to the new fixed weights.

[0053] In an exemplary embodiment, before determining that the health evaluation value of the selected line meets the preset safety conditions, the method further includes: monitoring the load efficiency of the selected line; and dynamically lowering the threshold of the preset safety conditions when the load efficiency is continuously lower than the historical level.

[0054] The selected line refers to the line currently prioritized for powering the load, determined by comparing health evaluation values. Load efficiency: The ratio of load output power to input power, reflecting the load's ability to convert electrical energy into usable energy. For loads whose output power is difficult to measure directly, their operating efficiency can be assessed through indirect parameters. "Continuously below historical levels" means that the load efficiency remains below a preset historical benchmark (e.g., 95% of the average efficiency over the past 24 hours) for a period of time (e.g., 10 consecutive minutes), indicating that the load's performance may be impaired due to deteriorating power quality. Preset safety condition threshold: The minimum health evaluation value set by the system to ensure stable load operation. When the value falls below this threshold, an optimized output strategy (e.g., switching to bridge circuit synthesis output) must be activated. Dynamically lowering the threshold: Reducing the preset safety condition threshold standard (e.g., from 0.8 to 0.75) allows the system to trigger optimization strategies earlier to address the problem of decreased load efficiency.

[0055] Optionally, based on the collected selected line voltage signal (line voltage RMS value) and load current signal (current RMS value), the real-time input power is calculated using a formula: ;in The power factor is calculated from the phase difference between the voltage and current waveforms.

[0056] For motor-type loads: monitor mechanical output parameters using speed sensors (such as encoders) and torque sensors, estimate mechanical output power by combining the motor speed-torque-power relationship curve, and then calculate efficiency (efficiency = mechanical output power / input electrical power); or indirectly reflect efficiency changes by analyzing current harmonic content, power factor, etc. (for example, an increase in harmonics is usually accompanied by a decrease in efficiency).

[0057] Lighting loads: Light output intensity is monitored by a light intensity sensor, and luminous efficacy (efficiency = light output power / input electrical power) is calculated in combination with input power.

[0058] General-purpose loads: For resistance heating equipment, heating efficiency can be indirectly assessed by monitoring it with a temperature sensor. Data recording and analysis: The system records load efficiency data in real time and establishes a historical database (such as storing the average efficiency and fluctuation range over the past 24 hours) as a benchmark for subsequent comparisons.

[0059] Continuously monitor the deviation of load efficiency from historical levels. When preset conditions are met, such as being 5% below the average efficiency of the past 24 hours for 10 consecutive minutes, it is determined to be consistently below historical levels. Threshold adjustment logic: Preset initial threshold (e.g., ... This information is stored in system memory. When trigger efficiency remains consistently low, the threshold is dynamically adjusted using an algorithm (e.g., reduced by 0.03-0.05), and the new threshold is... , ( (The adjustment range can be adaptively adjusted according to the degree of efficiency degradation). Effect after adjustment: The lowered threshold reduces the passing standard for the health evaluation value. Even if the health evaluation value of the selected line does not significantly decrease, the system can identify the risk of load performance degradation earlier and initiate optimized output strategies in advance (such as switching to a synthetic voltage output with better power quality), preventing further damage to the load due to long-term inefficient operation.

[0060] In an exemplary embodiment, after determining that the health evaluation value of the selected line meets the preset safety conditions, the method further includes: predicting the future deterioration trend of the health evaluation value of the selected line based on the time-series change data of the health evaluation value of the selected line; if the future deterioration trend does not meet the early warning safety conditions, then initiating preparations for synthesizing two-phase voltage output through a bridge circuit in advance.

[0061] Among them, the safety requirements for early warning safety conditions are lower than those for preset safety conditions.

[0062] It is understandable that the selected line refers to the line currently prioritized for supplying power to the load after comparing health evaluation values ​​(i.e., the line with the best health evaluation value). The time-series change data of the health evaluation value refers to the continuous record data of the selected line's health evaluation value over a past period (e.g., days or weeks), stored in chronological order (e.g., one sampling point per minute), reflecting the pattern of health changes over time. Future degradation trend: By analyzing the time-series change data, the system predicts the potential downward trend, magnitude, and possible minimum point of the health evaluation value within a specific future time window (e.g., the next 24 hours or week), used to identify potential risks of power quality deterioration in advance. Early warning safety conditions: The system presets a health evaluation value threshold for early warning, whose safety requirements are lower than the preset safety conditions (i.e., the warning threshold is more lenient and easier to trigger), aiming to prepare for emergencies before the health value reaches the mandatory switching threshold. Preset safety conditions: The minimum qualified threshold for the health evaluation value set by the system to ensure stable load operation; if it falls below this threshold, the system must immediately switch to bridge circuit synthesis output. Initiate preparations in advance: Before actually switching to the bridge circuit output, perform a series of operations in advance to ensure the speed and reliability of the switching and avoid interruptions caused by sudden failures.

[0063] Optionally, the health evaluation values ​​of the selected lines are continuously recorded at a preset period (e.g., once per minute) to form a time-series dataset, which is stored in non-volatile memory (e.g., flash memory of a DSP). The data retention period is configurable (e.g., retaining data from the past 4 weeks). An advanced predictive model is used to analyze the time-series data. In this embodiment, a Long Short-Term Memory (LSTM) neural network model is preferred, but Kalman filtering, ARIMA models, etc., can also be used. The model is trained offline using a large amount of historical power grid data and system operation logs, enabling it to capture nonlinear changes, periodic fluctuations, and random disturbances in the health evaluation values. Using the time-series data from the past 24 hours as input, the trained model infers the health change trend within a specific future time window (e.g., the next 48 hours). The output includes the future curve of the health evaluation value, the possible minimum point, and the confidence interval (e.g., 95% confidence level), quantifying the probability and degree of future deterioration.

[0064] The lowest predicted future health assessment value is compared with the threshold of the early warning safety condition. If the predicted value is lower than the early warning threshold (i.e., the early warning safety condition is not met), it indicates that the line health may deteriorate to a level requiring switching in the future, triggering preparatory work. The safety requirement of the early warning safety condition being lower than the preset safety condition means that the early warning threshold is lower than the preset safety threshold (e.g., early warning 0.75 < preset 0.8), meaning the early warning is triggered earlier, allowing time for preparatory work. Preparatory work for the bridge circuit's synthesized output includes, but is not limited to: pre-charging the DC bus capacitor of the bridge circuit to reduce the voltage settling time during formal startup; activating and detecting the gate drive circuit of the power devices to verify that the drive voltage, current, and switching delay are normal; preheating the control algorithm and parameters of the bridge circuit (e.g., starting PLL synchronization and PID parameter self-tuning) to ensure the control logic is ready; executing a comprehensive self-test procedure, including sensor calibration (voltage, current, and temperature sensors), communication link checks (e.g., signal transmission between the DSP and the drive circuit), relay / switch status detection, etc.; and placing the mechanical switch or relay for switching in standby mode to shorten the response time during actual switching (aiming for millisecond-level switching).

[0065] In one exemplary embodiment, after determining the selected line, the method further includes: Monitor the temperature of power devices on the selected line during operation; when the temperature of the power devices exceeds the first threshold, select the backup line combination with the best stability based on the historical trend of the health evaluation value of each line; at the voltage zero crossing point, switch the selected line to the backup line combination.

[0066] The selected line refers to the line currently prioritized for powering the load after comparing health evaluation values ​​(i.e., the line with the best health). Power devices: Core electronic components in the power system that perform power conversion or line switching, including solid-state relays (SSRs) and contactors used for line switching, and IGBTs (Insulated Gate Bipolar Transistors) or SiCMOSFETs (Silicon Carbide Metal Oxide Semiconductor Field-Effect Transistors) in bridge circuits used for voltage synthesis. Power device temperature: The temperature caused by heat generated by power devices during operation due to losses (conduction losses, switching losses), directly affecting device reliability and lifespan (excessive temperature accelerates aging and increases the risk of failure). First threshold: A preset safe upper limit for power device temperature (e.g., 80% of the IGBT junction temperature; the document example is 120℃). Exceeding this value indicates that the device is under high thermal stress and switching protection needs to be activated. Historical trend of health evaluation values ​​refers to the changing pattern of the health evaluation values ​​of each line during long-term operation (e.g., records from the past week or month). Trend analysis can be used to assess line stability (e.g., fluctuation amplitude, degradation rate). The optimal backup line combination for stability refers to the line pair (such as RS, ST, TR combinations) that exhibits the least fluctuation in health evaluation values ​​and the fewest transient changes during historical operation, and also has the lowest cumulative damage to corresponding power devices (such as switching cycles and thermal cycling). Voltage zero-crossing point: The moment when the AC voltage waveform transitions from the positive half-cycle to the negative half-cycle (or vice versa) and the voltage value is zero. Switching at this point minimizes current surges and switching losses. Switching: The operation of switching the load power supply from the currently selected line to the backup line combination using a switching device (such as a solid-state relay or vacuum contactor).

[0067] Optionally, a high-precision temperature sensor (such as a PT100 platinum resistance thermometer or an NTC thermistor) can be precisely mounted on the bottom of the heatsink of the power device or near the transistor package (to directly sense the device temperature). For IGBTs / SiC MOSFETs in bridge circuits, an on-chip temperature sensor (such as a junction temperature monitoring pin) can be integrated. The analog signal output by the temperature sensor is connected to the AD pin of the DSP / MCU after signal conditioning circuitry (such as amplification and filtering), or digital temperature data can be directly transmitted through a digital interface (such as I2C). The sampling frequency is typically 1-10 times per second to ensure real-time monitoring.

[0068] Based on the safe operating range of power devices (such as the maximum junction temperature in the datasheet), a 20% margin is reserved (e.g., when the maximum junction temperature is 150℃, the first threshold is set to 120℃), and stored in system memory. Health evaluation values ​​for each line are stored long-term (e.g., recorded once per minute, retaining data from the past three months). Trends are analyzed using algorithms such as linear regression and exponential smoothing to calculate indicators such as the standard deviation of health fluctuations and the average degradation rate to assess stability. From a preset line combination, the combination with the smallest historical health fluctuations (lowest standard deviation) and the fewest cumulative thermal cycles of the power devices is selected as a backup to ensure more stable operation after switching.

[0069] The line voltage signal is acquired by a high-precision voltage sensor, and combined with the phase-locked loop (PLL) circuit or digital comparator inside the DSP / MCU, the voltage zero-crossing point is identified in real time (error ≤10μs). When the zero-crossing point is detected, the DSP outputs a control signal to drive the switching device (such as a solid-state relay) to operate, ensuring that the voltage and current are close to zero at the moment of switching, reducing arcing, electromagnetic interference (EMI) and load impact, with a switching time ≤1ms.

[0070] Furthermore, based on the historical trend of the health evaluation value of each route, the backup route combination with the best stability is selected, including: based on the historical trend of the health evaluation value of each route, the switching path with the best electromagnetic compatibility is selected as the backup route combination with the best stability.

[0071] Among these, optimal electromagnetic compatibility (EMC) means minimal electromagnetic interference (such as common-mode noise, differential-mode noise, and radiated emissions) generated during line switching, ensuring no interference with surrounding sensitive electronic equipment (such as sensors and communication modules). Switching path: The physical circuit through which current flows during line switching (including wires, relays, connectors, etc.), and its parasitic capacitance and inductance characteristics directly affect the EMI level.

[0072] Optionally, the switching process of different line combinations can be tested in advance in an EMC laboratory to measure common-mode / differential-mode noise amplitude and radiated emission intensity (compliant with standards such as EN55011 and CISPR11), record EMI data under different currents and voltages, and establish an EMC characteristic database. When selecting a backup line combination, the path with the lowest EMI during switching should be prioritized based on historical health trends and the EMC database (such as line combinations with small parasitic parameters and good di / dt and dv / dt suppression), even if its health trend is slightly worse, to ensure the normal operation of peripheral equipment.

[0073] Furthermore, the method of synthesizing two-phase voltage output through a bridge circuit also includes: when the temperature of the power device exceeds a second preset threshold, enabling a multi-level topology to disperse thermal stress; after enabling the multi-level topology, prioritizing the allocation of switching tasks to the device with the highest remaining lifespan based on the cumulative damage status of the power device.

[0074] The second preset threshold is lower than the first threshold.

[0075] Understandably, the second preset threshold—a power device temperature warning value below the first threshold (110℃ in the document example)—is used to initiate preventative thermal management measures in advance to prevent the temperature from rising to the first threshold. Multi-level topology: A circuit structure that generates more voltage levels by combining multiple power devices (such as a midpoint-clamped NPC three-level inverter), which reduces voltage stress and switching losses of individual devices compared to traditional two-level topologies. Thermal stress: Mechanical and electrical stresses on power devices caused by temperature changes (such as decreased current carrying capacity and insulation aging due to high temperatures). Distributing thermal stress can extend device lifespan. Cumulative damage state: The degree of aging accumulated by power devices over long-term operation due to factors such as current, temperature, and switching frequency, assessed based on a physical failure model. Remaining lifetime: The estimated remaining operating time of a power device from its current state until failure, calculated using a cumulative damage model. Switching task allocation: In a multi-level topology, the strategy of allocating PWM switching actions to different power devices to balance load and thermal stress.

[0076] Optionally, based on the device's thermal characteristics, the threshold is set to 80%-90% of the first threshold (e.g., if the first threshold is 120℃, the second threshold is set to 110℃) to ensure early intervention. Multi-level topology switching: When the temperature exceeds the second threshold, the DSP control algorithm instructs the bridge circuit to switch from a two-level topology to a three-level NPC topology. This generates three levels—+Vdc / 2, 0, and -Vdc / 2—through clamping diodes and a split DC bus, reducing the voltage stress on individual devices (from Vdc to Vdc / 2), reducing switching losses, and making heat distribution more uniform. Real-time recording of device operating data (current, junction temperature, number of switching cycles, and number of thermal cycles) is used. Based on the Coffin-Manson model (relationship between lifetime and number of thermal cycles) and the wire bond fatigue model, cumulative damage and remaining lifetime are continuously estimated. In the multi-level topology, the DSP adjusts pulse width modulation (PWM) strategies (such as asymmetric PWM and carrier phase shift) to preferentially allocate switching events to devices with the highest remaining lifetime and lowest cumulative damage, reducing the switching frequency of high-damage devices, achieving load balancing, and maximizing the overall topology lifetime.

[0077] Furthermore, the basis for realizing the above-mentioned intelligent power switching method for three-phase power input is a three-phase power protection device. Functional modules can be expanded on the basis of the three-phase power protection device to realize the above-mentioned intelligent power switching method for three-phase power input.

[0078] like Figure 2 As shown, Figure 2This diagram illustrates the core functional architecture of a three-phase power protection device. With three-phase power as the core monitoring and protection target, it constructs a functional system encompassing energy supply, signal acquisition, core judgment, protection execution, and auxiliary interaction. Among them, the three-phase power is both an external energy input source (providing high voltage to the power supply section) and a monitoring signal source for the acquisition section (providing line voltage signals). Among them, the power supply section is the energy center of the entire device, responsible for converting the high voltage of three-phase electricity into the stable low voltage required by each module; The acquisition section consists of a sensing unit used to collect parameters such as the voltage of the three-phase power supply; the STM32 is the core control unit (i.e., the brain of the device), which receives signals from the acquisition section, combines them with threshold parameters (such as overvoltage and undervoltage thresholds) stored in the storage section to determine faults, and obtains accurate time using a clock chip (used to record the moment of the fault). The control section is the execution unit, which receives fault commands from the STM32 and cuts off the three-phase power circuit to achieve protection; the communication section is responsible for data interaction between the STM32 and external devices (such as a host computer), and can upload fault information. The human-machine interface is a window for manual operation and status viewing (such as displaying real-time voltage, fault type, or setting parameters via buttons); the storage section is used to retain key data such as fault records and system parameters, providing a basis for fault diagnosis and subsequent queries.

[0079] like Figure 3 As shown, the acquisition section converts the high-voltage AC voltage of three-phase electricity (such as 380V line voltage) into a low-voltage DC signal (0-3.3V) that the MCU can acquire. It also suppresses interference, protects downstream stages, and provides accurate data for fault diagnosis (overvoltage / undervoltage / phase loss). It includes three fully symmetrical circuits (corresponding to the AB, BC, and CA line voltages of the three-phase electricity). The acquisition section includes an AC rectification section: the key component is the DB107S single-phase full-bridge rectifier, which converts the input three-phase AC voltage into a unidirectional pulsating DC voltage, providing the foundation for subsequent DC processing. Overvoltage protection section: D1, D2, and D3 diodes are used, mainly to suppress transients or stabilize voltage, preventing high voltage in the front stage (such as power grid spikes) from damaging the fragile signal conditioning components in the back stage.

[0080] Voltage divider section: It consists of a voltage divider network composed of multiple sets of resistors, including 10kΩ R1-R3, 1MΩ RA1 and RA2, and 20kΩ RA3. Its core function is to reduce the high voltage DC after rectification (such as a peak value of about 537VDC after rectification) to a range that the MCU ADC can withstand (within 3.3V). The main voltage reduction is achieved by the resistor ratio of RA1, RA2, and RA3, while R1-R3 assists in fine-tuning the voltage to avoid exceeding the withstand voltage of subsequent components.

[0081] Signal conditioning section: An LM321 single op-amp is used, operating in voltage follower mode. Because the output impedance of the pre-stage voltage divider network is high (reaching the MΩ level), the voltage follower can increase the input impedance and decrease the output impedance, reducing distortion during signal transmission and achieving "isolation" between the pre-stage voltage divider and the subsequent MCU, ensuring stable acquisition voltage.

[0082] The filtering and decoupling section includes various capacitors and inductors. The 100nF capacitors C1, C5, and C8 are mainly used to filter out high-frequency noise and reduce the impact of high-frequency interference from the power grid on the acquired signal. The 1uF capacitors C2, C3, C6, and C7 are used to smooth the DC signal and reduce the voltage ripple after rectification. The 10uH capacitor L1 and the surrounding capacitors form an LC filter circuit to further suppress electromagnetic compatibility (EMC) interference and ensure that the final output signal to the MCU is clean and stable.

[0083] The working principle of the acquisition section is as follows: the three-phase wire voltage (such as AB phase 380VAC) needs to be processed through five steps: "rectification → filtering → voltage division → conditioning → re-filtering". The specific process is as follows: Rectification: The DB107S full-bridge rectifier with 380VAC line voltage input converts alternating positive and negative AC power into unidirectional pulsating DC power with a peak value of approximately 537VDC. Primary filtering: Pulsating DC passes through capacitors C2 (1uF) and C1 (100nF). The former smooths low-frequency ripple, while the latter filters out high-frequency noise, thus initially stabilizing the voltage. High voltage divider: The filtered high voltage DC enters the voltage divider network composed of RA1 (1MΩ), RA2 (1MΩ), and RA3 (20kΩ). Through the principle of resistor voltage divider, the 537VDC is reduced to about 5.2VDC. Then, through R4 and R5 (both 10kΩ) for fine adjustment, the voltage is finally controlled within 3.3V. Signal conditioning: The low-voltage signal after voltage division is input to the LM321 op-amp (voltage follower), and after impedance matching and signal isolation, the influence of the previous stage voltage divider network on the subsequent stage is eliminated, ensuring that the signal is transmitted without distortion. Secondary filtering: The conditioned signal passes through an LC filter circuit consisting of an L1 (10uH) inductor and C6 (1uF) and C7 (100nF) capacitors to filter out residual interference again, and finally outputs a stable DC signal to the ADC pin of the MCU (such as the PA port of the STM32 in the subsequent power supply module).

[0084] like Figure 4 As shown, the power supply section is responsible for converting the external high-voltage power supply (such as power drawn from three-phase power) into the stable low voltage (+5V, +3.3V) required by the system, while realizing overcurrent and surge protection and status indication, and powering the voltage acquisition, control module and MCU.

[0085] The power supply circuit is composed as follows: Input protection section: Includes three key components: First, F1-F35x20BLX-A type fuses, which melt when the circuit current exceeds the rated value, cutting off the circuit and preventing component burnout; second, R24, R25, R28 12Ω / 5W current-limiting resistors, which suppress the large current surge at the moment of power-on and protect the downstream voltage regulator components; third, D5-D10 1KV / 2A diodes, which absorb power grid surges (such as kilovolt-level voltages generated by lightning strikes) to prevent high voltage breakdown of subsequent circuits.

[0086] EMC filtering section: Core components include a Y1-grade 2.2nF / 250V safety capacitor C16, a 1.2mH inductor L2, a 1nF capacitor C17, and 47uF / 500V electrolytic capacitors C18 and C19. C16 suppresses common-mode interference (noise between the live and ground wires) through safety grounding; L2, in conjunction with the capacitor, filters out differential-mode interference (current fluctuations); C18 and C19 smooth the rectified DC voltage; and C17 further filters out high-frequency noise, ensuring a clean power signal.

[0087] The voltage regulation circuit consists of two core voltage regulator components: one is the ME6230A33M3GLDO voltage regulator chip, which is responsible for regulating the +5V voltage to +3.3V for use by the operational amplifiers of the MCU and voltage acquisition module; the other is the LS05-26B05R3 switching power supply module, which outputs a stable +5V voltage to power the relays and transistors of the control module.

[0088] The main control MCU section uses an STM32C011F6P6 microcontroller (based on the ARM Cortex-M0+ core), which is the "brain" of the device. It is responsible for receiving signals from the voltage acquisition module, judging faults (overvoltage / undervoltage, etc.), and outputting control commands to the control module.

[0089] The program download interface includes SWCLK, SWDIO, and RST pins, paired with a 2.54-1*3P pin H1 as the SWD download interface. It also has 10kΩ pull-up resistors R17 and R18 to ensure stable interface levels, facilitating connection to a debugger for program burning or online debugging.

[0090] Status indicator section: There are 4 LEDs and matching 1kΩ current limiting resistors. LED1 (red, with R16) indicates that the +3.3V power supply is normal, LED2 (yellow, with R19) indicates that the +5V power supply is normal, LED3 (green, with R20) indicates that the system is working normally, and LED4 (red, with R22) indicates the fault status.

[0091] Decoupling capacitor section: A 100nF capacitor C12 is connected in parallel next to the VSS pin of the STM32 to filter out power supply noise, ensure stable power supply to the MCU, and prevent noise from affecting its operation and control functions.

[0092] The working principle of the power supply section is as follows: The external power supply (drawn from three-phase electricity) needs to undergo "protection → filtering → voltage regulation" to supply power to the entire system, and the status is indicated in real time via LEDs. The specific process is as follows: Input protection: The external high-voltage power supply first passes through fuses F1-F3, which blow to protect against overcurrent; then it passes through current-limiting resistors such as R24 to suppress power-on surges; finally, surge diodes such as D5 absorb high-voltage spikes, completing the initial protection. EMC filtering: The protected power supply enters the filter network composed of L2 inductor and C16, C17, C18 and C19 to filter out common-mode and differential-mode interference and high-frequency noise, and output a smooth DC voltage. Regulated output: The filtered DC voltage is input to the LS05-26B05R3 switching power supply module, which outputs a +5V voltage. Part of the output is directly supplied to the control module, and the other part is input to the ME6230A33M3GLDO chip, where it is regulated to +3.3V and then supplied to the STM32 and voltage acquisition module. Status and debugging: +3.3V and +5V power supplies drive LED1 and LED2 respectively to light up, indicating that the power supply is normal; STM32 outputs "WORK" signal to drive LED3 to light up, indicating that the system is running; in case of a fault, STM32 drives LED4 to light up as an alarm; program burning and debugging can be completed through the SWCLK / SWDIO / RST interface.

[0093] like Figure 5 As shown, the control section is responsible for receiving fault commands from the MCU, cutting off the three-phase power circuit through relays to achieve protection, and using optocouplers to isolate strong and weak currents to avoid interference and ensure system safety. It includes three symmetrical relay drive circuits (corresponding to the three-phase AB, BC, and CA circuits).

[0094] The control section's circuitry includes: The isolation drive section uses a PC817B linear optocoupler, whose core function is to achieve electrical isolation between low voltage (MCU 3.3V control signal) and high voltage (relay +5V drive signal), preventing high voltage interference from entering the MCU and ensuring stable control signals and MCU safety.

[0095] Current amplification section: Using an S8050NPN transistor, since the optocoupler output current is small (cannot directly drive the relay), the transistor amplifies the current to the drive current required by the relay coil (50-100mA) to meet the relay's operating requirements.

[0096] The actuator section includes YAS2 / D2P22 relays (coils K1-K3) and corresponding contacts (K1_1-K3_1). When the coil is energized, it generates a magnetic field that attracts the armature, controlling the opening and closing of the contacts. The contacts are connected in series in the three-phase electrical circuit. When the contacts are opened, the power supply to the corresponding phase is cut off, thus achieving protection.

[0097] Status indicator section: There are LED5 (yellow), LED6 (green), and LED7 (red), paired with 330Ω current-limiting resistors (such as R34, R35, and R50). When the LEDs are lit, it indicates that the corresponding relay coil is energized and the contacts are activated, making it easy to observe the relay status intuitively.

[0098] The current limiting protection section includes two types of resistors: one is a 470Ω resistor (such as R37, R40, R53), which is connected in series with the base of the transistor to limit the base current and prevent overcurrent from burning out the transistor; the other is a 4.7kΩ resistor (such as R38, R41, R54), which is connected in series with the input side of the optocoupler to limit the optocoupler LED current and protect the optocoupler.

[0099] External interface section: There are two wiring terminals. CN3 (WJ2EDGRC-5.08-3P) is used to connect the relay contacts to the external three-phase power output circuit to realize the external execution of protection actions; CN4 (WAFER-XH254Z-8A) can expand the fault feedback signal (such as sending the relay action status back to the host computer).

[0100] Freewheeling protection section: LL4148 diodes (DJ1-DJ3) are used and connected in parallel across the relay coil. When the relay is de-energized, the coil will generate a reverse electromotive force, which the diodes can discharge to prevent the transistor from breaking down.

[0101] The control section works as follows: After the MCU detects a fault, it cuts off the three-phase power through "optocoupler isolation → transistor amplification → relay action". The core logic is "weak current controls strong current, isolation prevents interference". The specific process is as follows: Instruction trigger: When the STM32 detects a voltage abnormality (such as overvoltage), it outputs a 3.3V high-level control signal, which is sent to the anode of the input side of the PC817B optocoupler; Optocoupler isolation: The LED on the input side of the optocoupler (connected in series with a 4.7kΩ current-limiting resistor) is turned on and emits light, illuminating the phototransistor on the output side. The phototransistor is turned on by the light and outputs a +5V drive signal to achieve strong and weak current isolation. Transistor amplification: The drive signal output by the optocoupler is sent to the base of the S8050 transistor through a 470Ω current-limiting resistor. The transistor is saturated and conducts, outputting a sufficiently large collector current (to meet the requirements of the relay coil). Relay operation: The collector current of the transistor flows through the relay K1 coil, the coil attracts the armature, causing the K1_1 contact connected in series in the three-phase AB circuit to open, cutting off the AB phase power supply and completing the protection. Status and Protection: LED5 (yellow) is connected in parallel across the K1 coil. When the coil is energized, LED5 lights up, indicating that K1 is activated; LL4148 diode DJ1 discharges the reverse electromotive force when the coil is de-energized, protecting the transistor. External connection: Connect contacts such as K1_1 to an external three-phase power circuit via CN3 to realize protection action output; CN4 can be expanded to provide fault feedback function and transmit action status.

[0102] In summary, during the monitoring phase: the voltage acquisition module collects the three-phase line voltage in real time, and after rectification, voltage division, filtering, and conditioning, transmits the clean low-voltage signal to the STM32 MCU in the power supply module; Judgment Phase: The STM32 compares the acquired voltage signal with a preset threshold (e.g., 380V±10%) to determine whether there is an overvoltage, undervoltage, or phase loss fault. Execution phase: If a fault is detected, the STM32 outputs a control signal to the control module, which drives the relay after optocoupler isolation and transistor amplification to cut off the three-phase power circuit; at the same time, the LED4 (red) of the power module lights up to indicate the fault. Recovery phase: After the fault is cleared, the STM32 detects that the voltage has returned to normal, outputs a signal to reset the relay, the three-phase power circuit is turned on, and the system resumes operation.

[0103] It should be understood that although the steps in the flowcharts of the above embodiments are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the above embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0104] Based on the same inventive concept, this application also provides a control device for implementing the control of dynamic optimization of two-phase output of three-phase electricity as described above. The solution provided by this device is similar to the solution described in the above method. Therefore, the specific limitations of one or more embodiments of the control device for dynamic optimization of two-phase output of three-phase electricity provided below can be found in the limitations of the control method for dynamic optimization of two-phase output of three-phase electricity described above, and will not be repeated here.

[0105] In one exemplary embodiment, a control device for dynamically optimizing two-phase output of three-phase electricity is provided, comprising: The acquisition unit is used to acquire the line voltage and load current signals of the three-phase power supply. The identification unit is used to identify the load type based on the characteristics of the load current signal; The evaluation unit is used to determine the health evaluation value of each line based on the load type, harmonic distortion rate of the voltage per line, and voltage fluctuation rate. The selection unit is used to select the route with the best health rating as the selected route. The first output unit is used to output a two-phase voltage containing the selected line if the health evaluation value of the selected line meets the preset safety conditions. The second output unit is used to synthesize a two-phase voltage output through a bridge circuit if the preset safety conditions are not met.

[0106] Each module in the aforementioned three-phase dynamic optimization two-phase output control device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of a computer device in hardware form or independent of it, or stored in the memory of a computer device in software form, so that the processor can call and execute the operations corresponding to each module.

[0107] In one exemplary embodiment, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to perform the following steps: Acquire the line voltage and load current signals of the three-phase power supply; Identify the load type based on the characteristics of the load current signal; The health evaluation value of each line is determined based on the load type, the harmonic distortion rate of the voltage of each line, and the voltage fluctuation rate. Select the route with the best health rating as the chosen route; If the health evaluation value of the selected line is determined to meet the preset safety conditions, the output includes the two-phase voltage of the selected line. If the preset safety conditions are not met, a two-phase voltage output is synthesized through a bridge circuit.

[0108] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, the computer program performing the following steps when executed by a processor: Acquire the line voltage and load current signals of the three-phase power supply; Identify the load type based on the characteristics of the load current signal; The health evaluation value of each line is determined based on the load type, the harmonic distortion rate of the voltage of each line, and the voltage fluctuation rate. Select the route with the best health rating as the chosen route; If the health evaluation value of the selected line is determined to meet the preset safety conditions, the output includes the two-phase voltage of the selected line. If the preset safety conditions are not met, a two-phase voltage output is synthesized through a bridge circuit.

[0109] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, performs the following steps: Acquire the line voltage and load current signals of the three-phase power supply; Identify the load type based on the characteristics of the load current signal; The health evaluation value of each line is determined based on the load type, the harmonic distortion rate of the voltage of each line, and the voltage fluctuation rate. Select the route with the best health rating as the chosen route; If the health evaluation value of the selected line is determined to meet the preset safety conditions, the output includes the two-phase voltage of the selected line. If the preset safety conditions are not met, a two-phase voltage output is synthesized through a bridge circuit.

[0110] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.

[0111] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0112] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A control method for dynamic optimization of two-phase output in three-phase electricity, characterized in that, The method includes: Acquire the line voltage and load current signals of the three-phase power supply; The load type is identified based on the characteristics of the load current signal; Based on the load type, harmonic distortion rate of voltage per line, and voltage fluctuation rate, determine the health evaluation value of each line. Select the route with the best health rating as the chosen route; If the health evaluation value of the selected line is determined to meet the preset safety conditions, then the two-phase voltage of the selected line is output. If the preset safety conditions are not met, a two-phase voltage output is synthesized through a bridge circuit.

2. The method according to claim 1, characterized in that, The process of determining the health evaluation value for each line based on the load type, harmonic distortion rate of each line voltage, and voltage fluctuation rate includes: Based on the load type, determine the harmonic distortion weight corresponding to the harmonic distortion rate and the voltage fluctuation weight corresponding to the voltage fluctuation rate; wherein, when the load type is a motor load, the voltage fluctuation weight is greater than the harmonic distortion weight; when the load type is a lighting load, the harmonic distortion weight is greater than the voltage fluctuation weight; when the load type is a general load, the harmonic distortion weight is equal to the voltage fluctuation weight. The health evaluation value of each line is determined based on the harmonic distortion rate, voltage fluctuation rate, harmonic distortion weight, and voltage fluctuation weight of each line voltage.

3. The method according to claim 2, characterized in that, The process of determining the health evaluation value for each line based on its harmonic distortion rate, voltage fluctuation rate, harmonic distortion weight, and voltage fluctuation weight includes: When a change in the load type is detected, the migration rate of the harmonic distortion weight and the voltage fluctuation weight is dynamically adjusted according to the load power change rate. During the migration process of the harmonic distortion weight and the voltage fluctuation weight, a compensation factor positively correlated with transient current fluctuation is introduced to correct the health evaluation value. After the harmonic distortion weight and the voltage fluctuation weight have been migrated, the health evaluation value is calculated according to the fixed weight corresponding to the new load type.

4. The method according to claim 2, characterized in that, The process of determining the health evaluation value for each line based on its harmonic distortion rate, voltage fluctuation rate, harmonic distortion weight, and voltage fluctuation weight includes: During the calculation of the health assessment value, environmental temperature and humidity parameters are detected simultaneously; If the environmental temperature and humidity parameters exceed the preset range, the health evaluation value will be reduced and compensated accordingly. When the health evaluation value after derating compensation triggers the operation of synthesizing two-phase voltage output through bridge circuit, the circuit combination with the least influence from temperature and humidity is selected first.

5. The method according to claim 1, characterized in that, Before determining that the health evaluation value of the selected line meets the preset safety conditions, the method further includes: Monitor the load efficiency of the selected line; When the load efficiency remains below historical levels, the threshold of the preset safety condition is dynamically lowered.

6. The method according to claim 1, characterized in that, After determining that the health evaluation value of the selected line meets the preset safety conditions, the method further includes: Based on the time-series change data of the health evaluation value corresponding to the selected route, predict the future deterioration trend of the health evaluation value corresponding to the selected route; If the future degradation trend does not meet the early warning safety conditions, then the preparation work for the operation of synthesizing two-phase voltage output through bridge circuit will be started in advance. The safety requirements of the early warning safety conditions are lower than those of the preset safety conditions.

7. The method according to claim 1, characterized in that, After determining the selected line, the method further includes: Monitor the temperature of the power devices in the selected circuit during operation; When the temperature of the power device exceeds the first threshold, the backup line combination with the best stability is selected based on the historical trend of the health evaluation value of each line. At the moment the voltage crosses zero, the selected line is switched to the backup line combination.

8. The method according to claim 7, characterized in that, The selection of the optimal backup route combination based on the historical trend of the health evaluation value of each route includes: Based on the historical trend of the health evaluation value of each route, the switching path with the best electromagnetic compatibility is selected as the backup line combination with the best stability.

9. The method according to claim 7, characterized in that, The method of synthesizing two-phase voltage output via a bridge circuit also includes: When the temperature of the power device exceeds a second preset threshold, a multi-level topology is activated to disperse thermal stress; the second preset threshold is lower than the first threshold. After enabling the multi-level topology, switching tasks are preferentially assigned to the device with the highest remaining lifetime based on the cumulative damage status of the power devices.

10. A control device for dynamic optimization of two-phase output in three-phase electricity, characterized in that, The device includes: The acquisition unit is used to acquire the line voltage and load current signals of the three-phase power supply. The identification unit is used to identify the load type based on the characteristics of the load current signal; The evaluation unit is used to determine the health evaluation value of each line based on the load type, the harmonic distortion rate of the voltage per line, and the voltage fluctuation rate. The selection unit is used to select the route with the best health rating as the selected route. The first output unit is used to output a two-phase voltage containing the selected line if it is determined that the health evaluation value of the selected line meets the preset safety conditions. The second output unit is used to synthesize a two-phase voltage output through a bridge circuit if the preset safety conditions are not met.

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