Three-phase imbalance treatment system and method based on zero-millisecond seamless commutation

Abstract

The invention provides a three-phase imbalance management system and method based on zero-millisecond seamless commutation, and relates to the technical field of power distribution automation of a power system.The three-phase current and voltage data of the low-voltage side of a transformer are detected in real time through a master controller, and an optimal commutation instruction is generated in combination with load information uploaded by a phase converter; the phase converter realizes zero-millisecond seamless on-load commutation based on the unidirectional conduction characteristic of the thyristors, completes load switching through the coordination action of the relays and the thyristors, and solves the problem of power supply interruption in the traditional commutation process. The system adopts the AI intelligent balance algorithm to dynamically adjust the commutation strategy, significantly reduces the line loss and transformation loss of the transformer area, and improves the stability of the terminal voltage. The combination of the zero-millisecond commutation technology and the intelligent regulation and control algorithm can realize the real-time dynamic balance of the three-phase load, and is suitable for the imbalance treatment of various low-voltage distribution areas.

Description

Technical Field

[0001] This invention relates to the field of power system distribution automation technology, and in particular to a three-phase imbalance management system and method based on 0-millisecond seamless commutation. Background Technology

[0002] In low-voltage three-phase four-wire power distribution systems, the random distribution of single-phase loads and the volatility of electricity consumption behavior lead to widespread three-phase current imbalance. This results in transformer overheating losses, accelerated line aging, and low terminal voltage, severely impacting power supply reliability and economy. Existing mitigation technologies have significant limitations:

[0003] Traditional manual phase adjustment relies on regular on-site operations by maintenance personnel, which is not only labor-intensive and untimely, but also unable to cope with dynamic load changes, leading to repeated imbalances exceeding the standard (e.g., areas with a load rate of over 20% often experience instantaneous imbalances of over 50%). While improved SVG devices can transfer active power through power electronic converters, they have inherent drawbacks: their own losses are as high as 3% to 5%, actually increasing the total energy consumption of the area; the strong noise (exceeding 60 decibels) and harmonic interference generated during operation easily lead to user complaints and data collection system malfunctions; and they can only improve the three-phase balance of the transformer, failing to solve the problems of line losses and low terminal voltage, with the neutral current still remaining at a high level (often exceeding 100A).

[0004] While conventional intelligent phase-switching switches can achieve load switching, the commutation process involves a power interruption of more than 10ms, which can easily lead to abnormal operation of sensitive equipment (such as medical instruments and precision machine tools). Furthermore, due to the large inrush current (3-5 times the rated current), the commutation life is only about 20,000 cycles, forcing a daily limit of one commutation cycle, thus limiting the control effect. In addition, their communication often relies on traditional wireless methods, which are prone to signal interruptions in complex distribution area environments, leading to control failure.

[0005] Therefore, developing a three-phase imbalance control technology that combines zero-interruption commutation, low-loss operation, and intelligent dynamic regulation has become the key to solving the power quality problem in low-voltage distribution transformer areas. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a three-phase imbalance management system and method based on 0-millisecond seamless commutation. It achieves uninterrupted load switching through the coordinated control of thyristors and relays, and combines intelligent algorithms to dynamically optimize the commutation strategy, thereby significantly improving the management effect.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0008] The first aspect of this invention provides a three-phase imbalance mitigation system based on 0-millisecond seamless commutation, comprising:

[0009] The main controller is used to collect three-phase current and voltage data on the low-voltage side of the transformer in real time, receive load information uploaded by the commutator, and generate the optimal commutation command.

[0010] At least one commutator is communicatively connected to the main controller for receiving commutation commands and performing seamless load commutation operations with zero milliseconds. The commutator includes a commutation main circuit and a control module. The commutation main circuit achieves uninterrupted load switching through the coordinated action of thyristors and relays.

[0011] As a further improvement to the technical solution of the present invention, the commutation main circuit includes:

[0012] Three-phase live wire interface (A phase, B phase, C phase) and neutral wire interface (N);

[0013] At least three sets of relay switches (Ka, Kb, Kc) and their corresponding parallel-connected unidirectional thyristors (Da, Db, Dc);

[0014] The control module controls the activation and deactivation of the relay switch through the drive circuit, and, in conjunction with the unidirectional conduction and zero-crossing turn-off characteristics of the unidirectional thyristor, achieves seamless current transfer during the commutation process.

[0015] As a further improvement to the technical solution of the present invention, the main controller and the commutator realize data interaction through a LoRa wireless communication module, and the main controller is equipped with a 4G communication module for uploading the station operation data to the background system.

[0016] As a further improvement to the technical solution of the present invention, the commutation main circuit of the commutator is also equipped with a fuse and a current sampling unit. When the load current is detected to exceed the rated value of 120A, the fuse will automatically blow and trigger an alarm signal.

[0017] A second aspect of this invention provides a three-phase imbalance mitigation method based on 0-millisecond seamless commutation, comprising the following steps:

[0018] S1: The main controller monitors the three-phase currents (Ia, Ib, Ic) and neutral current (In) on the low-voltage side of the transformer in real time and calculates the three-phase unbalance ε.

[0019] S2: When ε exceeds the preset threshold, the main controller combines the current working phase and load current of each commutator to generate the target commutation combination scheme;

[0020] S3: The commutator receives the commutation command and completes seamless commutation with zero milliseconds by controlling the coordinated action of the relay and thyristor;

[0021] S4: After the phase commutation is completed, the main controller updates the load distribution data of the transformer area and repeats steps S1-S3 until the three-phase imbalance stabilizes within the threshold range.

[0022] As a further improvement to the technical solution of the present invention, the formula for calculating the three-phase unbalance ε in step S1 is as follows:

[0023] ε= (Imax - Imin) / Imax × 100%

[0024] Where Imax is the maximum value of the three-phase current and Imin is the minimum value of the three-phase current.

[0025] As a further improvement to the technical solution of the present invention, the specific process of 0-millisecond seamless commutation in step S3 includes:

[0026] At time t1: The control module issues commands to release the primary phase relay and trigger the primary phase thyristor to turn on, and to activate the target phase auxiliary relay and trigger the target phase thyristor to turn on.

[0027] At time t2: The relay operation is completed. The primary phase thyristor is turned on due to forward bias and trigger to maintain power supply; the target phase thyristor is turned off due to reverse bias, although there is a trigger signal.

[0028] At time t3: When the line voltage crosses zero, the target phase thyristor turns on and the original phase thyristor turns off, and the current is seamlessly transferred to the target phase;

[0029] At time t4: The control module issues commands to release the auxiliary relay and engage the main relay of the target phase;

[0030] At time t5: The main relay is energized, the thyristor is bypassed, and the commutation process ends.

[0031] As a further improvement to the technical solution of the present invention, the generation of the target commutation combination scheme in step S2 adopts an AI intelligent balancing algorithm, which calculates the commutation priority P using the following formula:

[0032] P = α×ΔI + β×Udrop + γ×C

[0033] Where ΔI is the current deviation of the phase where the commutator is located, Udrop is the voltage drop at the end, C is the cumulative number of commutator operations, and α, β, and γ are weighting coefficients with α+β+γ=1.

[0034] As a further improvement to the technical solution of the present invention, the current transfer time Δt in the commutation process of step S3 satisfies:

[0035] Δt = |Ua| = |Ub|, where |Uab| is the line voltage between phases A and B.

[0036] Δt=0ms.

[0037] A third aspect of the present invention provides a computer device, including a memory and a processor, wherein: when the processor executes a program stored in the memory, it implements a three-phase imbalance management method based on 0-millisecond seamless commutation.

[0038] A fourth aspect of the present invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements a three-phase imbalance management method based on 0-millisecond seamless commutation.

[0039] The present invention has the following beneficial effects:

[0040] Seamless commutation in 0 milliseconds: Through the coordinated control of thyristors and relays, load switching is achieved without interruption, solving the problem of power supply sag in traditional commutation.

[0041] Significantly reduced losses and energy savings: The system itself has a loss of only 0.05%, which can reduce line loss and transformer loss in the distribution area by more than 30%.

[0042] Intelligent dynamic adjustment: AI algorithms are used to optimize the commutation strategy in real time to adapt to load fluctuations.

[0043] High reliability: Dual protection of hardware interlock and software verification to avoid phase-to-phase short circuits, with a commutation life of ≥200,000 cycles.

[0044] This invention can be widely applied to transformer substations with prominent three-phase imbalance, such as those in urban villages and industrial parks. By dynamically balancing the three-phase load, it can improve power supply quality, reduce operation and maintenance costs, and has significant economic and social benefits. Attached Figure Description

[0045] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0046] Figure 1 is a structural framework diagram of a three-phase imbalance control system based on 0-millisecond seamless commutation according to an embodiment of the present invention;

[0047] Figure 2 is a schematic diagram of the commutation main circuit according to an embodiment of the present invention;

[0048] Figure 3 is a commutation timing waveform diagram of an embodiment of the present invention;

[0049] Figure 4 is a schematic diagram of the composition of a computing device according to an embodiment of the present invention;

[0050] Figure 5 This is a schematic diagram of a three-phase imbalance control method based on 0-millisecond seamless commutation according to an embodiment of the present invention. Detailed Implementation

[0051] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The illustrative embodiments and descriptions of the present invention are used to explain the present invention, but are not intended to limit the present invention.

[0052] It should be noted that all directional indicators (such as up, down, left, right, front, back, upper end, lower end, top, bottom, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0053] In this invention, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0054] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. If the combination of technical solutions is contradictory or impossible to implement, such a combination should be considered non-existent and not within the scope of protection claimed by this invention.

[0055] The present invention will be further described in detail below with reference to the accompanying drawings.

[0056] Reference Figure 1 A three-phase imbalance management system based on 0-millisecond seamless commutation includes:

[0057] The main controller is used to collect three-phase current and voltage data on the low-voltage side of the transformer in real time, receive load information uploaded by the commutator, and generate the optimal commutation command.

[0058] At least one commutator is communicatively connected to the main controller for receiving commutation commands and performing seamless load commutation operations with zero milliseconds. The commutator includes a commutation main circuit and a control module. The commutation main circuit achieves uninterrupted load switching through the coordinated action of thyristors and relays.

[0059] Specifically, in this embodiment, the commutation main circuit includes:

[0060] Three-phase live wire interface (A phase, B phase, C phase) and neutral wire interface (N);

[0061] At least three sets of relay switches (Ka, Kb, Kc) and their corresponding parallel-connected unidirectional thyristors (Da, Db, Dc);

[0062] The control module controls the activation and deactivation of the relay switch through the drive circuit, and the unidirectional conduction and zero-crossing turn-off characteristics of the thyristor enable seamless current transfer during the commutation process.

[0063] Specifically, in this embodiment, the main controller and the commutator communicate via a LoRa wireless communication module, and the main controller is equipped with a 4G communication module for uploading the station operation data to the backend system.

[0064] Specifically, in this embodiment, the commutation main circuit of the commutator is also equipped with a fuse and a current sampling unit. When the load current is detected to exceed the rated value of 120A, the fuse will automatically blow and trigger an alarm signal.

[0065] Reference Figure 5 The second aspect of this invention provides a three-phase imbalance mitigation method based on 0-millisecond seamless commutation, comprising the following steps:

[0066] S1: The main controller monitors the three-phase currents (Ia, Ib, Ic) and neutral current (In) on the low-voltage side of the transformer in real time and calculates the three-phase unbalance ε.

[0067] S2: When ε exceeds the preset threshold, the main controller combines the current working phase and load current of each commutator to generate the target commutation combination scheme;

[0068] S3: The commutator receives the commutation command and completes seamless commutation with zero milliseconds by controlling the coordinated action of the relay and thyristor;

[0069] S4: After the phase commutation is completed, the main controller updates the load distribution data of the transformer area and repeats steps S1-S3 until the three-phase imbalance stabilizes within the threshold range.

[0070] Specifically, in this embodiment, the formula for calculating the three-phase unbalance ε in step S1 is:

[0071] ε= (Imax - Imin) / Imax × 100%

[0072] Where Imax is the maximum value of the three-phase current and Imin is the minimum value of the three-phase current.

[0073] Specifically, in this embodiment, the 0-millisecond seamless commutation process in step S3 includes:

[0074] At time t1: The control module issues commands to release the primary phase relay and trigger the primary phase thyristor to turn on, and to activate the target phase auxiliary relay and trigger the target phase thyristor to turn on.

[0075] At time t2: The relay operation is completed. The primary phase thyristor is turned on due to forward bias and trigger to maintain power supply; the target phase thyristor is turned off due to reverse bias, although there is a trigger signal.

[0076] At time t3: When the line voltage crosses zero, the target phase thyristor turns on and the original phase thyristor turns off, and the current is seamlessly transferred to the target phase;

[0077] At time t4: The control module issues commands to release the auxiliary relay and engage the main relay of the target phase;

[0078] At time t5: The main relay is energized, the thyristor is bypassed, and the commutation process ends.

[0079] Specifically, in this embodiment, the generation of the target commutation combination scheme in step S2 adopts an AI intelligent balancing algorithm, which calculates the commutation priority P using the following formula:

[0080] P = α×ΔI + β×Udrop + γ×C

[0081] Where ΔI is the current deviation of the phase where the commutator is located, Udrop is the voltage drop at the end, C is the cumulative number of commutator operations, and α, β, and γ are weighting coefficients with α+β+γ=1.

[0082] Specifically, in this embodiment, the current transfer time Δt during the commutation process in step S3 satisfies:

[0083] Δt = |Ua| = |Ub|, where |Uab| is the line voltage of phases A and B.

[0084] Δt=0ms.

[0085] Specifically, in this embodiment, the third aspect of the present invention provides a computer device, including a memory and a processor, wherein: when the processor executes a program stored in the memory, it implements a three-phase imbalance management method based on 0-millisecond seamless commutation.

[0086] Specifically, in this embodiment, the third aspect of the present invention provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements a three-phase imbalance management method based on 0-millisecond seamless commutation.

[0087] Example:

[0088] Reference Figure 1 A three-phase imbalance management system based on 0-millisecond seamless commutation.

[0089] The system consists of a main controller and commutators, which communicate wirelessly via LoRa. The main controller, installed next to the transformer, is equipped with an open-type current transformer (CT) sensor, a 4G communication module, and an AI computing unit. It collects three-phase current and voltage data in real time and uploads it to the backend system. The commutators are installed at the T-junction of single-phase loads and feature a modular design, including a commutation main circuit, a control module, and a communication unit. Each commutator can control single-phase loads ranging from 10 to 70 A.

[0090] The core design of the commutation main circuit utilizes the unidirectional conduction characteristic of thyristors: during the commutation operation from phase A to phase B, seamless current transfer is achieved through the alternating conduction of Da and Db during the relay operation interval. Specifically, when the potential of phase A is higher than that of phase B, Da is forward biased and conducts to maintain the power supply to phase A; when the potential of phase B is higher than that of phase A, Db automatically conducts, and the current smoothly switches to phase B, with no power supply interruption throughout the entire process.

[0091] A Three-Phase Imbalance Mitigation Method Based on 0-Millisecond Seamless Commutation

[0092] The method includes the following steps:

[0093] Real-time monitoring of three-phase imbalance

[0094] The main controller acquires the three-phase currents Ia, Ib, and Ic via an open-type current transformer (CT) and calculates the unbalance.

[0095] ε = (Imax - Imin) / Imax × 100%

[0096] Where Imax is the maximum value of the three-phase current and Imin is the minimum value. When ε exceeds the threshold (25% for Dy-connected transformers and 15% for Yy-connected transformers), the commutation process is initiated.

[0097] Commutation priority calculation

[0098] The main controller sorts the commutation priority P of all commutators:

[0099] P = α×ΔI + β×Udrop + γ×C

[0100] In the formula:

[0101] ΔI = |Iφ - Iavg|, where Iφ is the current phase current of the commutator and Iavg is the average three-phase current.

[0102] Udrop = U_rated - U_terminal, reflecting the degree of voltage drop at the terminal.

[0103] C represents the cumulative number of commutator operations, which helps avoid excessively frequent commutations.

[0104] Weighting coefficients α=0.5, β=0.3, γ=0.2 (can be dynamically adjusted according to the characteristics of the transformer area).

[0105] Seamless commutation execution in 0 milliseconds:

[0106] Reference Figure 2 and Figure 3 Taking the switching from phase A to phase B as an example, before the commutation, because Ka is closed, Kb and Kc are released, and Da, Db, and Dc are all in the cut-off state, the commutator performs the following steps:

[0107] 1): At time t1, the MCU issues Da and Db trigger commands and Ka release commands.

[0108] 2): The relay completes its operation at time t2. At this time, the potential of phase A is higher than that of phase B, the bias voltage of thyristor Da changes from 0 to positive bias and turns on, while the bias voltage of thyristor Db is negative bias and remains off.

[0109] The circuit power supply is from A→Da→load→N, and the power supply from phase A to the load is still maintained.

[0110] 3): At time t3, since the potential of phase B is higher than that of phase A, the bias voltage of thyristor Da changes from positive bias to negative bias and is thus cut off, while the bias voltage of thyristor Db changes from negative bias to positive bias and is thus turned on.

[0111] At this time, the power supply of the circuit is from B→Db→load→N, that is, the power supply is from phase B to the load.

[0112] 4): At time t4, the MCU issues a release and engagement command for Kb, and the power supply circuit remains unchanged.

[0113] 5): At time t5, Kb is engaged and the system enters steady state. The commutation process ends, the power supply circuit maintains the supply of power from phase B to the load, and the commutation thyristor has been bypassed.

[0114] Evaluation of governance effectiveness

[0115] After commutation is completed, the main controller calculates the reduction in line loss:

[0116] ΔP line loss = (I original² - I new²) × R × t

[0117] Where Ioriginal is the line current before commutation, Inew is the line current after commutation, R is the line resistance, and t is the operating time. Simultaneously, the change in the neutral line current In is monitored; ideally, In can be reduced to below 50A.

[0118] To make the technical solution of this application clearer, the following detailed description is provided in conjunction with the actual application scenario of the three-phase imbalance mitigation system and method based on 0-millisecond seamless commutation:

[0119] System hardware configuration

[0120] Main controller: AT32F403A microprocessor, 10kHz sampling frequency, LoRa communication distance ≤4000m (unobstructed), operating temperature -40℃~85℃

[0121] Commutator: Rated current 120A, commutation time ≤0.1ms, using magnetic latching relay, operating life ≥200,000 cycles

[0122] Communication protocol: LoRaWAN protocol is used, with a data transmission rate of 50kbps and AES-128 encryption.

[0123] Commutation process waveform analysis

[0124] Monitoring the voltage waveform during the commutation process with an oscilloscope shows that the load voltage remains consistently at 220V ± 5% within the t2-t3 range, without any sag. The current waveform indicates that the surge current during commutation is ≤ 2 times the rated current, significantly lower than the 3-5 times of conventional commutation switches, effectively protecting user equipment.

[0125] Loss reduction effect verification

[0126] Taking a 500kVA transformer substation as an example, before the treatment, the neutral current was 450A and the line resistance was 0.2mΩ. After the treatment, the neutral current dropped to 50A. The neutral loss reduction is:

[0127] ΔP = (450² - 50²) × 0.2 × 10⁻³ × 24 = 960 degrees / day

[0128] Based on this calculation, the annual electricity saving is approximately 350,000 kWh, and the investment payback period is ≤2 years.

[0129] Specifically, the actual operation steps include:

[0130] 1. System Installation and Debugging Process

[0131] Installation and Deployment: The main controller is fixed inside the low-voltage side outgoing line cabinet of the transformer. It collects the three-phase currents (A, B, and C) via open-type current transformers (CTs) (500 / 5A ratio). Voltage sensors are connected in parallel between the three-phase live wires and the neutral wire (range 0-400V). The commutator is wall-mounted, 1.8-2.5m above the ground. Its input is connected to the main power line of the distribution area via a 6mm² copper cable, and its output is connected to the user load (single-phase two-wire system). The neutral wire is connected using a shared connection method.

[0132] Initialization and debugging:

[0133] Hardware verification: The main controller issues a self-test command, and the commutator performs three ABC phase switching cycles to detect the relay click sound, indicator light status, and communication response time (≤50ms).

[0134] Parameter configuration: Input transformer parameters (capacity, wiring method), transformer area line parameters (conductor type, length), unbalance threshold (default 15%) and commutation interval protection time (default 30s) in the main controller WEB interface.

[0135] Algorithm calibration: The no-load test method is adopted to record the inherent delay time of each commutator (usually ≤0.05us) under no-load conditions, and the compensation coefficient matrix of the AI ​​algorithm is entered.

[0136] 2. Adaptive adjustment strategies for different scenarios

[0137] In urban village transformer substations: Addressing the significant differences in load between morning and evening peak hours (peak times are 8 AM and 7 PM), the system automatically activates a dynamic threshold mode. During peak hours, the imbalance threshold is reduced to 10%, and relaxed to 20% during off-peak hours, minimizing ineffective commutation operations. The commutator prioritizes adjusting high-power loads such as air conditioners and electric water heaters, employing a "peak-off commutation" strategy (avoiding the 8 PM - 10 PM peak electricity consumption period).

[0138] Industrial Park Transit Area: Due to the presence of impact loads such as welding machines, the system has activated a fast response mode, increasing the current sampling frequency to 20kHz. The weighting coefficient α of ΔI in the commutation priority calculation formula has been adjusted to 0.7 to ensure that commutation is completed within 3 cycles (60ms) after the inrush current occurs. An RC absorption circuit (R=10Ω, C=10μF) has been added to the commutator main circuit to suppress surge voltage during commutation.

[0139] Agricultural irrigation and drainage areas: Considering the inductive characteristics of motor-type loads, a pre-excitation pulse (220V, 10ms duration) is output through the control module during commutation to avoid restart shock caused by motor demagnetization. A power factor correction term is added to the algorithm. When cosφ < 0.8 is detected, the load of that phase is adjusted first, and the calculation formula is updated to: P = 0.6×ΔI +0.2×Udrop + 0.1×C + 0.1×(1-cosφ).

[0140] 3. Fault Diagnosis and Self-Healing Mechanism

[0141] Commutator troubleshooting:

[0142] Relay sticking detection: The control module periodically (every 24 hours) issues a "test trip" command. If the current sampling unit detects that there is still current (>5A) after the phase is broken, it is determined that the relay is stuck, and the backup phase switching channel is immediately triggered (switched through K backup relay), and alarm information is uploaded.

[0143] Thyristor breakdown protection: When the phase-to-phase insulation resistance of the commutation main circuit is detected to be <500kΩ, the insulation monitoring program is started, the faulty thyristor is located by segmented testing, the commutator is automatically disconnected, and the load transfer scheme is activated (the load is temporarily switched to the adjacent commutator).

[0144] Communication interruption handling: If communication between the main controller and the commutator is interrupted for more than 10 seconds, the commutator automatically enters local autonomous mode and performs commutation operations based on the built-in simplified balancing algorithm (based solely on its own collected current data) until communication is restored. The main controller locally stores the interrupted data (capacity ≥ 100,000 records), which is automatically retransmitted after communication is restored.

[0145] In addition, this application also provides a computer device, referring to Figure 4 The computer device includes a memory and a processor. The memory stores code, and the processor is configured to retrieve the code and execute the above-described three-phase imbalance management method based on 0-millisecond seamless commutation.

[0146] In some embodiments, the three-phase imbalance management method based on 0-millisecond seamless commutation in the above embodiments can be implemented by a computer device, which includes at least one processor, a communication bus, a memory, and at least one communication interface.

[0147] A processor can be a general-purpose central processing unit (CPU) or an application-specific integrated circuit (ASIC).

[0148] A communication bus can be used to transmit information between the aforementioned components.

[0149] The memory can be read-only memory (ROM) or other types of static storage devices capable of storing static information and instructions, random access memory (RAM) or other types of dynamic storage devices capable of storing information and instructions, or electrically erasable programmable read-only memory (EEPROM), compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, universal optical discs, Blu-ray discs, etc.), magnetic disks or other magnetic storage devices, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but not limited to these. The memory can exist independently and be connected to the processor via a communication bus. The memory can also be integrated with the processor.

[0150] The memory stores program code that executes the solution of this application, and its execution is controlled by a processor. The processor executes the program code stored in the memory. The program code may include one or more software modules. The three-phase imbalance mitigation method based on 0-millisecond seamless commutation in the above embodiments can be implemented by the processor and one or more software modules in the program code in the memory.

[0151] A communication interface is a device that uses any transceiver or similar device to communicate with other devices or communication networks, such as Ethernet, radio access network (RAN), wireless local area networks (WLAN), etc.

[0152] In a specific implementation, as one example, a computer device may include multiple processors, each of which may be a single-core (single-CPU) processor or a multi-core (multi-CPU) processor. Here, a processor may refer to one or more devices, circuits, and / or processing cores used to process data (e.g., computer program instructions).

[0153] The aforementioned computer device can be a general-purpose computer device or a special-purpose computer device. In specific implementations, the computer device can be a desktop computer, a portable computer, a network server, a handheld digital assistant (PDA), a mobile phone, a tablet computer, a wireless terminal device, a communication device, or an embedded device. This application does not limit the type of computer device.

[0154] In addition, this application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described three-phase imbalance management method based on 0-millisecond seamless commutation.

[0155] This invention, through the synergistic innovation of 0-millisecond seamless commutation technology and intelligent control algorithm, has the following significant advantages compared to existing technologies:

[0156] Zero-millisecond uninterrupted power supply: Based on the unidirectional conduction characteristics of thyristors and the coordinated control of relays, the load current is seamlessly transferred through the thyristors during commutation, with a voltage interruption time of ≤0.1ms (actual measurement is 0ms). This solves the problem of equipment downtime and user complaints caused by the 10ms interruption of traditional commutation switches. As shown in a case study of a transformer substation, the voltage fluctuation at the user end during commutation is ≤±2V, the lighting does not flicker, and equipment such as air conditioners continues to operate.

[0157] Significant energy savings: The commutator's own loss is only 0.05%, far lower than the 3%~5% of SVG devices; by balancing the three-phase load, transformer losses and line losses can be reduced simultaneously, with a comprehensive energy saving rate of over 30%. Taking a 500kVA distribution area as an example, after the treatment, the neutral line current dropped from 450A to below 50A. Calculated based on a line resistance of 0.2mΩ, the monthly loss reduction of the neutral line alone reaches 5760 kWh. Combined with the reduction in losses of the live wire and transformer, the annual electricity saving exceeds 100,000 kWh, with an investment payback period of ≤2 years.

[0158] Intelligent Dynamic Balancing: Employing an AI-powered intelligent balancing search algorithm, the system accurately locates imbalance points using the formula ΔU_dif = Max(|Ua-Ub|,|Ub-Uc|,|Uc-Ua|), and dynamically adjusts the commutation strategy based on load characteristics (e.g., automatically tightening the threshold to 10% during peak hours in urban village transformer areas). The main controller and commutator communicate via LoRa (distance ≤ 4000m, bit error rate < 10⁻). 6 This enables coordinated control of multiple commutators, reducing the three-phase imbalance from 50% to below 15%.

[0159] High reliability and long lifespan: The hardware adopts a fuse + automatic bypass protection design, with a failure rate of <0.1 times / year; the relay adopts magnetic latching technology, with a commutation inrush current of <2 times the rated current and a lifespan of ≥200,000 cycles (calculated at 50 cycles per day, it can operate for more than 10 years), with no limit on the number of commutations per day, ensuring continuous balance under dynamic load.

[0160] Improving end-point voltage quality: By balancing the three-phase current and reducing line voltage drop, the end-point voltage can be increased by 10-50V. As shown in a case study of a transformer substation, after the treatment, the end-point voltage increased from 146V to over 200V, completely resolving issues such as air conditioners failing to start and appliances burning out, and reducing the user complaint rate to zero.

[0161] Highly adaptable and interference-free: Supports Dy / Yy connected transformer areas, and can operate stably in areas with a load rate of 20%~100%; generates no harmonics and does not interfere with the centralized meter reading system; LORA communication has strong anti-blocking ability, with a communication success rate of ≥99.9% in densely built-up urban village environments, meeting the control needs of complex transformer areas.

[0162] The technical solutions provided by the embodiments of the present invention have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the embodiments of the present invention. The descriptions of the embodiments above are only for helping to understand the principles of the embodiments of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the embodiments of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A three-phase imbalance mitigation system based on 0-millisecond seamless commutation, characterized in that, include: The main controller is used to collect three-phase current and voltage data on the low-voltage side of the transformer in real time, receive load information uploaded by the commutator, and generate the optimal commutation command. At least one commutator is communicatively connected to the main controller for receiving commutation commands and performing seamless load commutation operations with zero milliseconds. The commutator includes a commutation main circuit and a control module. The commutation main circuit achieves uninterrupted load switching through the coordinated action of thyristors and relays.

2. The three-phase imbalance control system based on 0-millisecond seamless commutation according to claim 1, characterized in that: The commutation main circuit includes: Three-phase live wire interface and neutral wire interface; Three sets of relay switches and their corresponding parallel-connected unidirectional thyristors; The control module controls the activation and deactivation of the relay switch through the drive circuit, and, in conjunction with the unidirectional conduction and zero-crossing turn-off characteristics of the unidirectional thyristor, achieves seamless current transfer during the commutation process.

3. The three-phase imbalance mitigation system based on 0-millisecond seamless commutation according to claim 1, characterized in that: The main controller and the commutator communicate via a LoRa wireless communication module. The main controller is equipped with a 4G communication module for uploading the station's operating data to the backend system.

4. A three-phase imbalance mitigation method based on 0-millisecond seamless commutation, characterized in that, The following steps are involved: S1: The main controller monitors the three-phase current and neutral line current on the low-voltage side of the transformer in real time and calculates the three-phase unbalance ε. S2: When ε exceeds the preset threshold, the main controller combines the current working phase and load current of each commutator to generate the target commutation combination scheme; S3: The commutator receives the commutation command and completes seamless commutation with zero milliseconds by controlling the coordinated action of the relay and thyristor; S4: After the phase commutation is completed, the main controller updates the load distribution data of the transformer area and repeats steps S1-S3 until the three-phase imbalance stabilizes within the threshold range.

5. The three-phase imbalance mitigation method based on 0-millisecond seamless commutation according to claim 4, characterized in that: The formula for calculating the three-phase unbalance ε in step S1 is: ε= (Imax - Imin) / Imax × 100% Where Imax is the maximum value of the three-phase current and Imin is the minimum value of the three-phase current.

6. The three-phase imbalance mitigation method based on 0-millisecond seamless commutation according to claim 4, characterized in that: The specific process of 0-millisecond seamless commutation in step S3 includes: At time t1: The control module issues commands to release the primary phase relay and trigger the primary phase thyristor to turn on, and to activate the target phase auxiliary relay and trigger the target phase thyristor to turn on. At time t2: The relay completes its operation, and the primary thyristor is triggered and forward biased to maintain power supply; At time t3: When the voltage crosses zero, the target phase thyristor is turned on by forward bias and the original phase thyristor is turned off by negative bias, and the current is seamlessly transferred to the target phase; At time t4: The control module issues commands to release the auxiliary relay and engage the main relay of the target phase; At time t5: The main relay is energized, the thyristor is bypassed, and the commutation process ends.

7. The three-phase imbalance mitigation method based on 0-millisecond seamless commutation according to claim 4, characterized in that: In step S2, the target commutation combination scheme is generated using an AI intelligent balancing algorithm. This algorithm calculates the commutation priority P using the following formula: P = α×ΔI + β×Udrop + γ×C Where ΔI is the current deviation of the phase where the commutator is located, Udrop is the voltage drop at the end, C is the cumulative number of commutator operations, and α, β, and γ are weighting coefficients with α+β+γ=1.

8. The three-phase imbalance mitigation method based on 0-millisecond seamless commutation according to claim 4, characterized in that: The current transfer time Δt during the commutation process in step S3 satisfies: Δt = |Ua| = |Ub|, that is, the line voltage of line voltage |Uab| crosses zero, Δt = 0ms.

9. A computer device, comprising a memory and a processor, characterized in that, When the processor executes a program stored in the memory, it implements the method as described in any one of claims 4-8.

10. A computer-readable storage medium storing a computer program, characterized in that, When the program is executed by the processor, it implements the method as described in any one of claims 4-8.

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