Thyristor-based power grid power regulation system, integrated terminal and control method

Abstract

This invention discloses a thyristor-based power grid regulation system, a fusion terminal, and a control method, relating to AC voltage regulation technology in distribution networks. The system includes a master controller, a slave controller, a heartbeat monitoring module, and a metering module. The metering module collects real-time power grid operating parameters from the input and load sides. The heartbeat monitoring module determines whether the slave controller has malfunctioned based on the heartbeat pulse signal sent by the slave controller. When the slave controller is operating normally, the master controller sends a first control command to control the slave controller to generate a thyristor trigger pulse signal. When the slave controller malfunctions, the master controller stops sending the first control command and generates the thyristor trigger pulse signal itself. This invention, through master-slave controller redundancy design and automatic fault switching mechanism, enables the master controller to achieve low-latency switching when the slave controller crashes, thus ensuring uninterrupted power supply to downstream loads and guaranteeing power supply reliability and security.

Description

Technical Field

[0001] This invention relates to AC power regulation technology for power distribution networks, specifically a power regulation system, integrated terminal, and control method based on thyristors. Background Technology

[0002] In power distribution networks, dynamic voltage regulation of transformer outlet voltage is typically required to achieve energy conservation and loss reduction, cope with fluctuations in renewable energy sources, or meet the voltage demands of specific users. Currently, one of the mainstream voltage regulation technologies is the use of AC power regulators based on power electronic devices (such as three-phase thyristors). These regulators use a microcontroller to precisely calculate and generate trigger pulses, controlling the thyristor's conduction time within each power frequency cycle (phase-controlled chopping) or the number of waveforms conducting within multiple power frequency cycles (zero-crossing waveform dropping), thereby changing the effective value of the output voltage and achieving power regulation of the downstream load. Existing AC power regulators generally adopt a single controller architecture, where the controller (usually an MCU or DSP) simultaneously undertakes tasks such as real-time voltage regulation control (generating thyristor trigger pulses), data communication (interacting with a host computer), and status monitoring. In practical applications, this architecture poses a risk of global failure if the controller malfunctions due to software crashes, hardware damage, or external electromagnetic interference (such as EFT bursts). This can manifest in two ways: 1. Power outage risk: If all thyristors are turned off, the power supply to the downstream load will be interrupted; 2. Voltage runaway: If the thyristors are mistakenly triggered to full conduction or a fixed conduction angle, the output voltage may exceed the rated value, burning out sensitive equipment. This "single point of failure" mode severely impacts the reliability of the power supply and is unacceptable in applications requiring high power supply continuity.

[0003] To improve the reliability of AC power regulators, redundancy designs have been introduced, primarily in three ways: 1. Using dual controllers operating simultaneously and synchronizing their states via software communication. This method relies on a software handshake protocol for switching, resulting in long delays and failing to meet power supply continuity requirements. Furthermore, the logic of the primary and backup controllers is complex. 2. Adding an external watchdog timer. This uses an independent watchdog chip to detect controller crashes and reset them. During the reset process, the system remains uncontrolled. 3. Using dual controllers with a hardware switching switch for primary / backup switching. This hardware switching switch typically uses a mechanical relay. Mechanical relays have drawbacks in practical applications, including long operating times and the risk of secondary faults due to contact arcing. The switching process can also cause power interruptions.

[0004] In summary, even with redundant design, existing AC power regulators still cannot meet the power supply continuity requirements of important loads when applied to applications with high power supply continuity requirements. Summary of the Invention

[0005] The purpose of this invention is to solve the problem that existing AC power regulators cannot guarantee the continuity of power supply. It provides a thyristor-based power grid regulation system, integrated terminal and control method. Through the redundancy design of master and slave controllers and the automatic fault switching mechanism, the master controller can achieve low-latency switching when the slave controller fails. In this way, the power supply to the back-end load is not interrupted, thereby ensuring the reliability and safety of power supply.

[0006] The objective of this invention is mainly achieved through the following technical solutions:

[0007] A thyristor-based power grid control system includes a master controller, slave controllers, a heartbeat monitoring module, and a metering module, wherein:

[0008] The main controller is used to calculate and generate a first control command and send it to the slave controller according to a first set cycle and based on the real-time collected power grid operating parameters when the slave controller is operating normally; it is used to calculate and generate a thyristor trigger pulse signal according to a first set cycle and based on the real-time collected power grid operating parameters when the heartbeat monitoring module determines that the slave controller is faulty; it is used to generate the first control command again and send it to the slave controller after the heartbeat monitoring module determines that the slave controller fault has been cleared, and the main controller stops generating the thyristor trigger pulse signal after sending the first control command again.

[0009] The controller is used to receive the first control command sent by the main controller and generate a thyristor trigger pulse signal according to the first control command; it is also used to send a heartbeat pulse signal to the heartbeat monitoring module according to a second set period.

[0010] The heartbeat monitoring module is used to continuously receive heartbeat pulse signals sent from the controller, determine whether the controller has malfunctioned based on the received heartbeat pulse signals, and send the determination result to the main controller.

[0011] The metering module is used to collect grid operation parameters from the grid input side and load side in real time and send them to the main controller and slave controller.

[0012] Furthermore, the heartbeat monitoring module determines whether the slave controller has malfunctioned by detecting whether the level of the heartbeat pulse signal received within two consecutive second set periods changes. If the level of the heartbeat pulse signal received within two consecutive second set periods changes, the slave controller is determined to be operating normally; otherwise, the slave controller is determined to have malfunctioned. After determining that the slave controller has malfunctioned, the heartbeat monitoring module continues to acquire heartbeat pulse signals. When the level of the heartbeat pulse signal received within two consecutive second set periods changes, the slave controller is determined to have resumed normal operation. The heartbeat monitoring module sends the determination results of the slave controller malfunction and resumption of normal operation to the main controller.

[0013] Furthermore, when the time for receiving the first control command from the controller exceeds a set time limit threshold, the controller calculates and generates a thyristor trigger pulse signal according to the real-time collected power grid operating parameters according to a first set period, until the number of times the time for receiving the first control command from the controller is within the time limit threshold reaches a set number threshold, and then the controller generates a thyristor trigger pulse signal according to the first control command; wherein, the time limit threshold is greater than the first set period.

[0014] Furthermore, the thyristor of the power grid power regulation system is a three-phase thyristor voltage regulation module connected to the main controller and the slave controller. The three-phase thyristor voltage regulation module is used to receive thyristor trigger pulse signals sent by the main controller or the slave controller to realize load voltage regulation.

[0015] A thyristor is a semi-controlled device; its conduction requires a trigger signal, while its turn-off depends on the current flowing through it decreasing below its "holding current" (i.e., current crossing zero). When the downstream load is very small (small load) or completely empty (no load), the current flowing through the thyristor may consistently be lower than its holding current, causing the thyristor to fail to conduct stably after being triggered, or to experience irregular turn-off after conduction. This results in severe distortion of the output voltage waveform, voltage instability, or even runaway voltage, seriously affecting power quality and potentially damaging sensitive downstream equipment. Therefore, existing AC power regulators suffer from poor adaptability to small load / no-load conditions, and there is no effective solution for this situation. To address this issue, a further thyristor-based grid power regulation system includes a bypass switching module connected in parallel with the three-phase thyristor voltage regulation module. This bypass switching module is used to close during small load or no-load conditions, allowing grid current to directly supply power to the load through the bypass switching module.

[0016] Furthermore, the controller that generates the thyristor trigger pulse signal between the main controller and the slave controller is the controller with control authority. This controller compares the acquired real-time current of the downstream load with a set bypass switching threshold. When the time the real-time current of the downstream load is less than the bypass switching threshold exceeds a first set time threshold, it is determined to be a low-load or no-load condition. The controller with control authority then stops generating the thyristor trigger pulse signal, delays for the first set delay time, and then controls the bypass switching module to close, allowing the grid current to directly power the load through the bypass switching module. In bypass direct-through mode, the controller with control authority continues to acquire the real-time current of the downstream load and compares the acquired real-time current with a set voltage regulation recovery threshold. The values ​​are compared. When the real-time current of the back-end load is greater than the voltage regulation recovery threshold, the controller with control identifies whether there is an inductive load in the back-end load. If there is no inductive load, it is directly determined that the back-end load has returned to normal. The controller with control controls the bypass switching module to disconnect. After a second set delay time, the controller with control resumes generating the thyristor trigger pulse signal. If there is an inductive load, when the time for the real-time current of the back-end load to be greater than the voltage regulation recovery threshold exceeds the second set time threshold, it is determined that the load has returned to normal. The controller with control controls the bypass switching module to disconnect. After a second set delay time, the controller with control resumes generating the thyristor trigger pulse signal. The voltage regulation recovery threshold is greater than the bypass switching threshold.

[0017] Furthermore, the controller with control identifies whether the back-end load is inductive by means of the following: the controller with control calculates the slope characteristics of the current waveform within a specific time period over multiple consecutive cycles by using the current waveform sampling points collected by the metering module to determine whether the back-end load is inductive.

[0018] A fusion terminal integrates the aforementioned thyristor-based power grid regulation system, wherein the communication module of the fusion terminal enables remote information interaction with the master controller and slave controller of the power grid regulation system.

[0019] The control method for the above-mentioned thyristor-based power grid power regulation system includes a master-slave controller redundancy and fault switching method, wherein the master-slave controller redundancy and fault switching method includes the following steps:

[0020] Step S11: After the power grid power regulation system is powered on, the main controller calculates and generates the first control command according to the real-time collected power grid operating parameters according to the first set cycle, receives the first control command from the controller and generates a thyristor trigger pulse signal according to the first control command;

[0021] Step S12: The controller sends heartbeat pulse signals to the heartbeat monitoring module according to the second set cycle. The heartbeat monitoring module determines whether the controller is faulty by detecting whether the level of the heartbeat pulse signals received within two consecutive second set cycles changes. If the level of the heartbeat pulse signals received within two consecutive second set cycles changes, the controller is determined to be operating normally, and the main controller continues to send the first control command; if the level of the heartbeat pulse signals received within two consecutive second set cycles does not change, the controller is determined to be faulty, and the fault determination result of the controller is sent to the main controller, proceeding to step S13.

[0022] Step S13: The main controller calculates and generates thyristor trigger pulse signals according to the real-time collected power grid operating parameters according to the first set cycle;

[0023] Step S14: The heartbeat monitoring module determines that the controller continues to acquire heartbeat pulse signals after a fault. When the level of the heartbeat pulse signal received changes within two consecutive second set cycles, it determines that the controller has resumed normal operation and sends the determination result of the controller resuming normal operation to the main controller. The main controller then sends the first control command again and stops generating thyristor trigger pulse signals.

[0024] The control method for a thyristor-based power grid power regulation system further includes an adaptive bypass switching method. This adaptive bypass switching method is implemented after the power grid power regulation system is equipped with a bypass switching module. The controller that generates the thyristor trigger pulse signal between the main controller and the slave controller is the controller with control authority. The adaptive bypass switching method includes the following steps:

[0025] Step S21: The controller with control compares the real-time current of the back-end load with the set bypass switching threshold. When the real-time current of the back-end load is less than the bypass switching threshold for a period of time exceeding the first set time threshold, it is determined to be a small load or no-load condition. The controller with control stops generating thyristor trigger pulse signals, delays for the first set delay time, and then controls the bypass switching module to close, so that the grid current directly supplies power to the load through the bypass switching module.

[0026] Step S22: In bypass direct-through mode, the controller with control continues to acquire the real-time current of the downstream load and compares the acquired real-time current of the downstream load with the set voltage regulation recovery threshold. When the real-time current of the downstream load is greater than the voltage regulation recovery threshold, the controller with control identifies whether there is an inductive load in the downstream load. If there is no inductive load, it is directly determined that the downstream load has recovered to normal, and the controller with control controls the bypass switching module to disconnect. After a second set delay time, the controller with control resumes generating the thyristor trigger pulse signal. If there is an inductive load, when the time for the real-time current of the downstream load to be greater than the voltage regulation recovery threshold exceeds the second set time threshold, it is determined that the load has recovered to normal, and the controller with control controls the bypass switching module to disconnect. After a second set delay time, the controller with control resumes generating the thyristor trigger pulse signal. Wherein, the voltage regulation recovery threshold is greater than the bypass switching threshold.

[0027] Existing methods using thyristor chopping essentially adjust the duty cycle through switching to directly change the pulse width of the voltage applied across the load. That is, by changing the average or effective value of the load voltage, a method of controlling the electrical signal (voltage) waveform parameters is used to ultimately achieve continuous regulation of the load power. Wavelet dropping, on the other hand, achieves voltage regulation on a multi-cycle scale by periodically triggering and blocking the thyristor. Wavelet dropping regulates voltage by controlling the on / off ratio of multiple complete waveforms, belonging to periodic control. From the perspective of means and results, this invention is a technical solution for regulating load power using chopping and wavelet dropping as voltage regulation methods.

[0028] In summary, the present invention has the following advantages compared with the prior art: (1) By introducing a master-slave device control architecture, the present invention ensures that when the master controller fails, the system can automatically and with low latency switch to the backup controller to take over the control, thereby ensuring the continuity of the voltage regulation function and the continuity of the back-end power supply, avoiding power outage accidents caused by controller crashes, and thus solving the reliability problem of power outage caused by single point of failure.

[0029] (2) This invention achieves intelligent switching of the system's operating mode under different load conditions by adding an adaptive bypass switching function. Under light load or no-load conditions, it automatically switches to bypass direct-through mode to avoid the weaknesses of thyristor operation and ensure stable and high-quality output voltage; under normal load conditions, it switches back to thyristor voltage regulation mode to perform fine power regulation. In this way, this invention can solve the problems of control failure and voltage distortion under light load / no-load conditions. Attached Figure Description

[0030] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0031] Figure 1 This is a system block diagram of a power grid power regulation system in a specific embodiment of the present invention;

[0032] Figure 2 This is a flowchart of a master-slave controller redundancy and fault switching method in a specific embodiment of the present invention;

[0033] Figure 3 This is a flowchart of an adaptive bypass switching method based on operating conditions in a specific embodiment of the present invention. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0035] Example 1:

[0036] like Figure 1 As shown, a thyristor-based power grid control system includes a main controller, a slave controller, a heartbeat monitoring module, and a metering module. The main controller is used to: generate a first control command and send it to the slave controller according to a first set cycle and based on real-time collected power grid operating parameters during normal operation of the slave controller; calculate and generate a thyristor trigger pulse signal according to the first set cycle and based on real-time collected power grid operating parameters when the heartbeat monitoring module determines a fault in the slave controller; and generate the first control command again and send it to the slave controller after the heartbeat monitoring module determines that the slave controller fault has been cleared. The main controller stops generating thyristor trigger pulse signals after sending the first control command again. The slave controller receives the first control command sent by the main controller and generates a thyristor trigger pulse signal according to the first control command; it also sends a heartbeat pulse signal to the heartbeat monitoring module according to a second set cycle. The heartbeat monitoring module continuously receives the heartbeat pulse signal sent by the slave controller, determines whether the slave controller has malfunctioned based on the received heartbeat pulse signal, and sends the determination result to the main controller. The metering module collects power grid operating parameters from the power grid input side and load side in real time and sends them to the main controller and the slave controller.

[0037] In this embodiment, both the master controller and the slave controller employ high-performance microprocessors, such as the AT32F403A chip, forming a master-slave redundant control architecture. During normal operation, a "slave-master control, master-monitor" mode is used. That is, routine voltage regulation commands are directly executed by the slave controller. The master controller handles more advanced tasks, such as communicating with the host computer, processing complex algorithms, storing historical data, and monitoring the slave controller's status in real time via a heartbeat monitoring module.

[0038] In this embodiment, during normal operation of the slave controller, the process of the master controller generating the first control command is as follows: a. Real-time acquisition of power grid operating parameters (such as input voltage, current, output load current, power factor, etc.). b. Calculation of the required voltage adjustment ratio based on the voltage regulation target (e.g., maintaining the output voltage at 220V±2%) and real-time parameters. c. Selection of control mode (chopping or dropout) based on load type (resistive / inductive) and current operating condition (light load / heavy load). d. Calculation of specific control command values, for example: chopping mode: calculate the conduction angle α, and then convert it into the command "chopping X%" (where X% = (180°-α) / 180° * 100%); dropout mode: calculate the on / off ratio, for example, 3 cycles on and 1 cycle off, then the command is "dropout 25%" (because the off ratio is 25%, the actual output voltage is 75%). e. Encoding the command into a data frame (containing command type, value, checksum, etc.) and sending it to the slave controller.

[0039] The process of generating a trigger pulse signal from the controller based on the first control command includes: a. parsing the command to obtain the control type and value; b. converting the command type into power electronic level control parameters.

[0040] Chopper command: Converts the percentage to the conduction angle α (e.g., "Chopper 30%" corresponds to α=180°*(1-0.3)=126°).

[0041] Drop Wave Command: Converts the percentage to the number of on / off cycles (for example, "drop wave 20%" means 20% off, so if the total number of cycles in the cycle group is set to 5, then 1 cycle will be off and 4 cycles will be on).

[0042] c. Generate a trigger pulse based on the converted parameters:

[0043] Chopping: A trigger pulse (pulse width typically tens to hundreds of microseconds) is emitted after a delay of α angle at the start of each half-wave (voltage zero-crossing point). Dropping: A trigger pulse is emitted immediately at the start of each half-wave in the conduction cycle (N_on consecutive cycles) (i.e., α=0°), and no trigger pulse is emitted in the turn-off cycle (N_off cycles). d. The trigger pulse is amplified by the drive circuit and then sent to the thyristor gate.

[0044] In this embodiment, the relationship between the first control command and the trigger pulse is as follows: the control command is a high-level, abstract strategy description (such as "chopping 30%)", while the slave controller converts it into a specific, real-time generated trigger pulse signal (i.e., the specific trigger time and pulse width for each cycle). This is a "strategy-execution" decomposition, where the master controller is responsible for strategy calculation, and the slave controller is responsible for real-time execution.

[0045] In this embodiment, when the slave controller fails, the master controller takes over the slave controller's real-time triggering function: a. The master controller collects grid operating parameters in real time. b. It directly calculates power electronic control parameters based on the voltage regulation target (i.e., it no longer generates high-level instructions, but directly calculates the conduction angle α or the number of on / off cycles). c. Then, the real-time triggering module inside the master controller generates trigger pulse signals based on these parameters (for chopper control: the master controller needs to detect the voltage zero-crossing point in real time, then calculate the trigger delay time based on α, and then output the trigger pulse; for wave dropping control: the master controller needs to count the power frequency cycles, triggering immediately when each half-wave crosses zero during the conduction cycle, and not triggering during the turn-off cycle). d. The trigger pulse is output from the master controller's output port, passing through the drive circuit to the thyristor.

[0046] In this embodiment, the first control command generated by the main controller based on the grid status is a high-level strategy command (such as "chop 30%)", which is an application-oriented abstract command. The controller performs real-time calculations to transform the abstract command into power electronic level parameters (such as conduction angle α = 108°). The hardware output of the trigger pulse involves precise timing control. There is a three-level signal conversion and cooperative control relationship between the high-level command issued by the main controller and the thyristor trigger pulse generated by the controller. Its technical essence is a decoupled architecture of "strategy-algorithm-execution". This decoupled architecture is quite common in existing technologies, and its specific implementation will not be elaborated here. In this embodiment, the calculation and generation of the first control command and thyristor trigger pulse signal based on the real-time collected grid operating parameters are based on existing technologies, which will also not be elaborated here.

[0047] In this embodiment, the heartbeat monitoring module determines whether the slave controller is faulty by detecting changes in the level of the received heartbeat pulse signal within two consecutive second-set periods. If the level of the received heartbeat pulse signal changes within two consecutive second-set periods, the slave controller is determined to be operating normally; otherwise, a fault is determined. After determining a fault in the slave controller, the heartbeat monitoring module continues to acquire heartbeat pulse signals. When the level of the received heartbeat pulse signal changes within two consecutive second-set periods, the slave controller is determined to have resumed normal operation. The heartbeat monitoring module sends the determination results of the slave controller's fault and resumption of normal operation to the main controller. In a specific implementation of this embodiment, the heartbeat monitoring module can also be implemented as an independent logic unit built in hardware based on existing technology. In a specific implementation of this embodiment, the slave controller sends pulse waveforms at 1ms intervals, and the heartbeat monitoring module detects changes in the level of the received heartbeat pulse signal at 1ms intervals. If no level change is detected for two consecutive periods, a fault is determined in the slave controller, and the main controller controls the thyristor.

[0048] The metering module in this embodiment includes an incoming-side metering module and an outgoing-side metering module. The incoming-side metering module measures the grid operating parameters on the input side and outputs synchronization pulses to the master and slave controllers. The outgoing-side metering module measures the grid operating parameters on the load side and outputs synchronization pulses to the master and slave controllers. The grid operating parameters include voltage, current, power, frequency, and other parameters. Both the incoming-side and outgoing-side metering modules in this embodiment include a metering chip and voltage and current transformers connected to the metering chip. In specific implementations, the voltage transformer is preferably ZMPT107-1, the current transformer is preferably TA12-100, and the metering chip is preferably V9203. This embodiment achieves the following through parameter acquisition by the incoming-side metering module: grid synchronization signal capture—real-time detection of the incoming voltage zero-crossing point to provide a phase reference for thyristor triggering; grid operating parameter monitoring—acquiring input voltage, current, frequency, and phase angle for voltage regulation strategy calculation (such as chopper / dropout mode selection). This embodiment achieves the following through parameter acquisition by the outgoing line metering module: real-time load condition judgment—monitoring the effective value of the load-side current and driving bypass switching decisions; voltage regulation closed-loop control feedback—comparing the output voltage / current sample with the set value and dynamically adjusting the conduction angle. This embodiment calculates and generates thyristor trigger pulse signals based on data acquired by the incoming and outgoing line metering modules, and then controls the three-phase thyristor voltage regulation module to regulate voltage. This is based on existing technology and will not be elaborated further here.

[0049] In this embodiment, when the time it takes for the controller to receive the first control command exceeds a set time-out threshold, the controller calculates and generates a thyristor trigger pulse signal according to the real-time collected power grid operating parameters at a first set cycle. This continues until the number of times the controller continuously receives the first control command within the time-out threshold reaches a set threshold. Then, the controller generates the thyristor trigger pulse signal again based on the first control command. The time-out threshold is greater than the first set cycle. Thus, in this embodiment, a malfunction of the main controller can prevent the normal issuance of the thyristor trigger pulse signal, thereby ensuring the voltage regulation function. Both the main controller and the slave controller in this embodiment are equipped with watchdog chips, which automatically restart and reset in the event of a fault.

[0050] In this embodiment, the thyristors in the power grid power regulation system are three-phase thyristor voltage regulation modules connected to the master and slave controllers. These modules receive thyristor trigger pulse signals from the master or slave controllers to regulate the load voltage. This embodiment's three-phase thyristor voltage regulation module includes six pairs of anti-parallel thyristors, corresponding to phases A, B, and C respectively, and is the core power unit for voltage regulation. Its trigger signal originates from the controller currently in control. In specific implementation, this embodiment uses anti-parallel thyristor groups (such as 40TPS12), one pair per phase, to achieve full-wave AC control. To ensure strong electrical isolation and rapid triggering, this embodiment also includes a trigger circuit composed of high-speed optocouplers (such as HCPL-316J) and gate drive resistors. This trigger circuit is specifically located on the line between the master / slave controllers and the three-phase thyristor voltage regulation module. To suppress voltage spikes, this embodiment also includes an RC snubber circuit connected in parallel with the thyristors.

[0051] This embodiment also includes a bypass switching module connected in parallel with the three-phase thyristor voltage regulating module. The bypass switching module is used to close under low load or no-load conditions, allowing grid current to directly power the load through the bypass switching module. The bypass switching module in this embodiment consists of three sets of bypass switches connected in parallel across the three-phase thyristor voltage regulating module. When the bypass switch is closed, the grid current directly bypasses the three-phase thyristor voltage regulating module to power the downstream load. In specific implementation, the bypass switching module is implemented using a mechanical relay or a solid-state relay (SSR). Mechanical relays (such as G7L-2A-BUBJ-CB) are low-cost and suitable for scenarios with infrequent switching. Solid-state relays (SSRs) (such as CPC1976B) can achieve zero-voltage switching (arc-free) and are suitable for high-frequency switching. For applications with frequent switching or higher switching speed requirements, a static transfer switch (STS) composed of fully controlled devices such as solid-state relays or IGBTs can also be used to achieve faster, arc-free switching.

[0052] like Figure 2 As shown, the control method for the thyristor-based power grid regulation system includes a master-slave controller redundancy and fault switching method, wherein the master-slave controller redundancy and fault switching method includes the following steps:

[0053] Step S11: After the power grid power regulation system is powered on, the main controller calculates and generates a first control command based on the real-time collected power grid operating parameters according to a first set cycle. The slave controller receives the first control command and generates a thyristor trigger pulse signal based on the first control command. In this embodiment, after the power grid power regulation system is powered on, the slave controller is assumed to be operating normally and in control. The main controller enters monitoring mode, and the slave controller generates a precise thyristor trigger pulse signal based on the first control command sent by the main controller (such as "chop 30%" or "drop 20%").

[0054] Step S12: The slave controller sends heartbeat pulse signals to the heartbeat monitoring module according to the second set period. The heartbeat monitoring module determines whether the slave controller is faulty by detecting whether the level of the heartbeat pulse signals received within two consecutive second set periods changes. If the level of the heartbeat pulse signals received within two consecutive second set periods changes, it is determined that the slave controller is operating normally, and the master controller continues to send the first control command; if the level of the heartbeat pulse signals received within two consecutive second set periods does not change, it is determined that the slave controller is faulty, and the fault determination result of the slave controller is sent to the master controller, proceeding to step S13. In this embodiment, the slave controller sends pulses to the heartbeat monitoring module through an internal timer at the second set period (this is a fixed period, set to 1ms in this embodiment). If the heartbeat monitoring module fails to receive the pulses from the slave controller within two consecutive second set periods (set to 2ms in this embodiment), it determines that the slave controller is faulty (such as crashing or communication interruption).

[0055] Step S13: The main controller calculates and generates thyristor trigger pulse signals according to the real-time collected power grid operating parameters according to the first set cycle. In this embodiment, when a slave controller fault is determined, the main controller immediately executes the control takeover procedure: (a) The main controller switches to master control mode and calculates and generates thyristor trigger pulses. (b) The main controller reports a slave fault alarm through the display or communication interface.

[0056] Step S14: The heartbeat monitoring module determines that the slave controller continues to acquire heartbeat pulse signals after a fault. If the level of the received heartbeat pulse signal changes within two consecutive second-set cycles, it determines that the slave controller has resumed normal operation and sends the determination result to the master controller. The master controller then sends the first control command again and stops generating thyristor trigger pulse signals. In this embodiment, when the slave controller resumes normal operation (e.g., after a watchdog reset) and can respond to heartbeats again, a safety time can be set according to the actual operating conditions. The master controller will only return control to the slave controller at a certain safety time. In specific implementation, this embodiment can still choose to continue to hold control. After the fault is recovered, the master controller can autonomously decide whether to return control, improving system flexibility.

[0057] like Figure 3 As shown, this embodiment also includes an adaptive bypass switching method based on operating conditions. The controller that generates the thyristor trigger pulse signal between the master controller and the slave controller is the controller with control authority. The adaptive bypass switching method based on operating conditions includes the following steps:

[0058] Step S21: The controller with control compares the real-time current of the back-end load with the set bypass switching threshold. When the real-time current of the back-end load is less than the bypass switching threshold for a period of time exceeding the first set time threshold, it is determined to be a small load or no-load condition. The controller with control stops generating thyristor trigger pulse signals, delays for the first set delay time, and then controls the bypass switching module to close, so that the grid current directly supplies power to the load through the bypass switching module.

[0059] Step S22: In bypass direct-through mode, the controller with control continues to acquire the real-time current of the downstream load and compares it with the set voltage regulation recovery threshold. When the real-time current of the downstream load is greater than the voltage regulation recovery threshold, the controller with control identifies whether the downstream load has an inductive load. If there is no inductive load, the downstream load is directly determined to be back to normal, and the controller with control disconnects the bypass switching module. After a second set delay time, the controller with control resumes generating a thyristor trigger pulse signal. If there is an inductive load, the load is determined to be back to normal when the time for the real-time current of the downstream load to be greater than the voltage regulation recovery threshold exceeds the second set time threshold. The controller with control disconnects the bypass switching module, and after a second set delay time, the controller with control resumes generating a thyristor trigger pulse signal. The voltage regulation recovery threshold is greater than the bypass switching threshold. Specifically, "downstream load back to normal" means that the downstream load is not under low load or no-load conditions.

[0060] When the downstream load is a resistive device, the current and voltage waveforms are standard sine waves, and their characteristics are easy to extract. When the downstream load is an inductive device, the current waveform will exhibit a shape similar to a square wave, and the voltage waveform will be a sine wave. Therefore, chopping in the few milliseconds before the current crosses zero is almost useless for power regulation, so a chopping delay needs to be added. For inductive devices, the ideal inductance L is assumed to be a constant. However, in actual electromagnetic devices, the coil is usually wound on an iron core to enhance the magnetic field. The permeability of the iron core material (such as silicon steel sheet) is not linear; it has a limit. When the current is small, the core is not saturated, and the permeability is very high, so the inductance L is also large. According to V = L * di / dt, a large L will suppress rapid changes in current, causing the current to rise slowly, which conforms to the theoretical waveform. However, when the applied voltage is high enough and the duration is long enough, the current continues to increase, and the magnetic flux density in the iron core reaches its physical upper limit (saturation magnetic flux density Bs). At this point, the iron core is like a "full cup," unable to store any more magnetic field energy. Once saturated, the permeability of the iron core drops sharply to near the level of air, causing the inductance L of the coil to become extremely small instantaneously. The impedance Z of the device, which was originally R + jωL (where L is very large), suddenly becomes almost solely the DC resistance of the coil winding, a resistance that is typically very small.

[0061] For resistive loads, since the current and voltage are in phase, the current instantaneously returns to zero along with the voltage at the moment of switching, and no sudden energy change occurs during switching. Therefore, this embodiment adopts an immediate switching method, which improves the system response speed. When an inductive load is present, the current phase lags behind the voltage. In bypass shoot-through mode, if a sudden switch to thyristor chopper control occurs, two serious problems may arise due to the release of inductor stored energy: first, high dv / dt may cause thyristor false triggering; second, current discontinuity may cause voltage spikes. Therefore, this embodiment delays switching when an inductive load is present, providing time for the inductor stored energy to be released, thereby avoiding the risks of voltage breakdown and magnetic saturation during the transient process of inductive load switching.

[0062] Based on the above phenomena, in this embodiment, the controller with control authority uses the current waveform sampling points collected by the metering module to calculate the slope characteristics of the current waveform within a specific time period over multiple consecutive cycles to determine whether the downstream load is inductive. Then, it adjusts the power of the corresponding downstream load using a corresponding algorithm. In specific implementation, this embodiment uses the outgoing-side metering module to capture the load-side current waveform at a sampling rate of not less than 4 kHz, starting at time t0 after the grid voltage crosses zero, and extracting the waveform for a duration T. w For a current data segment of 200 μs, perform linear fitting on the data segment and calculate the current change rate k = Δi / Δt; if the current change rate is greater than or equal to the current change rate threshold k... thIf the current change rate is less than the current change rate threshold k, it is determined to be a resistive load. th This is determined to be an inductive load. In this embodiment, the current change rate threshold k... th The value is based on the system's rated voltage V. N and minimum identifiable inductance L min Dynamic adjustment, the calculation formula is: k th =(η*V N ) / L min η is the safety factor, used as an engineering correction factor, with a value ranging from 0.15 to 0.25. In this embodiment, a value of 0.2 is preferred. min The value is 1mH. In this embodiment, different strategies are adopted for the two different waveforms: square wave control is used for inductive loads to avoid magnetic saturation, while sine wave control is used for resistive loads to ensure power quality.

[0063] In this embodiment of the adaptive bypass switching method, the controller with control continuously reads the real-time current of the downstream load through the outgoing line metering module. When the real-time current of the downstream load is detected to be below the bypass switching threshold for a period of time (e.g., 3 seconds), the system is determined to enter a low-load or no-load operating condition. The controller with control performs the following operations:

[0064] (a) Stop sending any trigger signals to the thyristor voltage regulation module.

[0065] (b) Delay for a short period of time (e.g., 20ms, to ensure that all thyristors have been turned off).

[0066] (c) When the three sets of switches of the bypass switching module are closed, the grid current directly supplies power to the load through the bypass. The system enters the "bypass direct mode". In this embodiment, the trigger signal is stopped first, then a 20ms delay is made to ensure that the thyristor is turned off, and then the bypass switch is closed, which can avoid voltage transient fluctuations.

[0067] In bypass pass-through mode, the controller continues to monitor the real-time current of the downstream load. When the real-time current of the downstream load is detected to be higher than the voltage regulation recovery threshold, if there is no inductive load, the downstream load is directly determined to have returned to normal. If there is an inductive load, the downstream load is determined to have returned to normal only if the time for the real-time current of the downstream load to be higher than the voltage regulation recovery threshold exceeds a second set time threshold (set to 1 minute in this embodiment). After the downstream load returns to normal, the controller with control performs the following operations:

[0068] (a) The three sets of switches of the control bypass switching module are disconnected.

[0069] (b) Delay for a short period of time (e.g., 5ms to ensure the switch is stable when disconnected).

[0070] (c) Restore the trigger control of the three-phase thyristor voltage regulation module, and the system enters the "thyristor voltage regulation mode".

[0071] In this embodiment, the real-time load current is compared with the preset bypass switching threshold and voltage regulation recovery threshold. The bypass switching threshold is a minimum value, which is set to 0.5A in this embodiment. The voltage regulation recovery threshold is set to 1.0A in this embodiment.

[0072] In this embodiment, the design of the voltage regulation recovery threshold being greater than the bypass switching threshold forms a hysteresis loop, which can effectively prevent the system from experiencing frequent and unstable mode switching when the load current fluctuates just around the threshold.

[0073] This embodiment has the following advantages in practical implementation:

[0074] Extremely high power supply reliability: Through the redundant design of the master-slave controller and the automatic fault switching mechanism, the single point of failure problem of traditional single-controller power regulation devices is solved. Even if the master controller fails, the backup controller can seamlessly take over, ensuring uninterrupted power supply to the downstream loads, greatly improving the reliability and security of the system.

[0075] Excellent adaptability to all operating conditions: The system solves the problem of unstable operation of thyristors under low load / no-load conditions, leading to voltage distortion, through the operating condition adaptive bypass switching function. The system can intelligently switch between voltage regulation and shoot-through modes, ensuring the provision of high-quality and stable power under any load conditions, thus broadening the application scenarios of the device.

[0076] The advanced and flexible system architecture: The clear division of labor in the "slave controller, master monitor" mode makes the slave controller firmware extremely stable and streamlined, and less prone to errors; while the master controller can carry out complex communication, data processing and human-machine interaction functions, which facilitates future function expansion and software upgrades, and improves the maintainability and scalability of the system.

[0077] Improving power quality: By switching to bypass under low load, harmonics and voltage fluctuations caused by irregular switching of thyristors are avoided, ensuring the power quality for downstream users, and especially protecting sensitive equipment.

[0078] Example 2:

[0079] A converged terminal integrates the thyristor-based power grid regulation system described in Embodiment 1. The converged terminal and the master and slave controllers of the power grid regulation system achieve remote information interaction through a communication module. In this embodiment, the power grid regulation system is a logical function extension unit of the converged terminal, rather than a physically integrated component within the converged terminal. The converged terminal receives real-time operating status data, fault records, and power quality parameters from the master and slave controllers. Furthermore, the converged terminal can generate voltage regulation strategy optimization instructions based on the received data and distribute them to the master and slave controllers. Thus, the converged terminal performs data aggregation, edge computing, and collaborative control functions.

[0080] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A thyristor-based power grid control system, characterized in that, It includes a main controller, slave controllers, a heartbeat monitoring module, and a metering module, among which: The main controller is used to calculate and generate a first control command and send it to the slave controller according to a first set cycle and based on the real-time collected power grid operating parameters when the slave controller is operating normally; it is used to calculate and generate a thyristor trigger pulse signal according to a first set cycle and based on the real-time collected power grid operating parameters when the heartbeat monitoring module determines that the slave controller is faulty; it is used to generate the first control command again and send it to the slave controller after the heartbeat monitoring module determines that the slave controller fault has been cleared, and the main controller stops generating the thyristor trigger pulse signal after sending the first control command again. The controller is used to receive the first control command sent by the main controller and generate a thyristor trigger pulse signal according to the first control command; it is also used to send a heartbeat pulse signal to the heartbeat monitoring module according to a second set period. The heartbeat monitoring module is used to continuously receive heartbeat pulse signals sent from the controller, determine whether the controller has malfunctioned based on the received heartbeat pulse signals, and send the determination result to the main controller. The metering module is used to collect grid operation parameters from the grid input side and load side in real time and send them to the main controller and slave controller; During normal operation of the controller, the process by which the main controller generates the first control command is as follows: a. Real-time acquisition of power grid operating parameters; b. Calculate the required voltage adjustment ratio based on the voltage regulation target and real-time parameters; c. Select the control mode based on the load type and current operating conditions; d. Calculate the specific control command values; e. Encode the instruction into a data frame and send it to the slave controller; The controller generates a trigger pulse signal based on the first control command, including: a. Parse the instructions to obtain the control type and value; b. Convert the command type into power electronic level control parameters; c. Generate a trigger pulse based on the converted parameters; In the event of a controller failure, the master controller takes over the real-time triggering function of the slave controller: a. The main controller collects power grid operating parameters in real time; b. Calculate the power electronic control parameters directly based on the voltage regulation target; c. Then, the real-time triggering module inside the main controller generates trigger pulse signals based on these parameters; d. The trigger pulse is output from the output port of the main controller and passes through the drive circuit to the thyristor.

2. The thyristor-based power grid regulation system according to claim 1, characterized in that, The heartbeat monitoring module determines whether the slave controller is faulty by detecting whether the level of the heartbeat pulse signal received within two consecutive second set periods changes. If the level of the heartbeat pulse signal received within two consecutive second set periods changes, the slave controller is determined to be operating normally; otherwise, the slave controller is determined to be faulty. The heartbeat monitoring module determines that it continues to acquire heartbeat pulse signals after the controller fails, and determines that the controller has resumed normal operation when the level of the heartbeat pulse signal received changes within two consecutive second set cycles. The heartbeat monitoring module will send the judgment results of controller failure and recovery to normal operation to the main controller.

3. The thyristor-based power grid regulation system according to claim 1, characterized in that, When the time for receiving the first control command from the controller exceeds a set time limit threshold, the controller calculates and generates a thyristor trigger pulse signal according to the real-time collected power grid operating parameters according to a first set period, until the number of times the time for receiving the first control command from the controller is within the time limit threshold reaches a set number threshold, and then the controller generates a thyristor trigger pulse signal according to the first control command; wherein, the time limit threshold is greater than the first set period.

4. The thyristor-based power grid regulation system according to any one of claims 1 to 3, characterized in that, The thyristors in the power grid power regulation system are three-phase thyristor voltage regulation modules connected to the main controller and the slave controller. The three-phase thyristor voltage regulation module is used to receive thyristor trigger pulse signals sent by the main controller or the slave controller to realize load voltage regulation.

5. The thyristor-based power grid regulation system according to claim 4, characterized in that, It also includes a bypass switching module connected in parallel with the three-phase thyristor voltage regulation module. The bypass switching module is used to close under small load or no-load conditions so that the grid current can directly supply power to the load through the bypass switching module.

6. The thyristor-based power grid regulation system according to claim 5, characterized in that, The controller that generates the thyristor trigger pulse signal between the main controller and the slave controller is the controller with control authority. This controller compares the acquired real-time current of the downstream load with a set bypass switching threshold. If the time the real-time current of the downstream load is less than the bypass switching threshold exceeds a first set time threshold, it is determined to be a low-load or no-load condition. The controller with control authority then stops generating the thyristor trigger pulse signal, delays for the first set delay time, and then controls the bypass switching module to close, allowing the grid current to directly power the load through the bypass switching module. In bypass direct-through mode, the controller with control authority continues to acquire the real-time current of the downstream load and compares it with a set voltage regulation recovery threshold. In comparison, when the real-time current of the back-end load exceeds the voltage regulation recovery threshold, the controller with control identifies whether there is an inductive load in the back-end load. If there is no inductive load, it directly determines that the back-end load has returned to normal, and the controller with control disconnects the bypass switching module. After a second set delay time, the controller with control resumes generating the thyristor trigger pulse signal. If there is an inductive load, when the time for the real-time current of the back-end load to exceed the voltage regulation recovery threshold exceeds the second set time threshold, it determines that the load has returned to normal, and the controller with control disconnects the bypass switching module. After a second set delay time, the controller with control resumes generating the thyristor trigger pulse signal. Here, the voltage regulation recovery threshold is greater than the bypass switching threshold.

7. The thyristor-based power grid regulation system according to claim 6, characterized in that, The controller with control identifies whether the back-end load is inductive by means of the following: the controller with control calculates the slope characteristics of the current waveform within a specific time period over multiple consecutive cycles by using the current waveform sampling points collected by the metering module to determine whether the back-end load is inductive.

8. A converged terminal, characterized in that, The fusion terminal integrates the thyristor-based power grid regulation system according to any one of claims 1 to 7, and the communication module of the fusion terminal enables remote information interaction with the master controller and slave controller of the power grid regulation system.

9. A control method for a thyristor-based power grid power regulation system according to any one of claims 1 to 7, characterized in that, This includes a master-slave controller redundancy and fault switching method, which includes the following steps: Step S11: After the power grid power regulation system is powered on, the main controller calculates and generates the first control command according to the real-time collected power grid operating parameters according to the first set cycle, receives the first control command from the controller and generates a thyristor trigger pulse signal according to the first control command; Step S12: The controller sends heartbeat pulse signals to the heartbeat monitoring module according to the second set cycle. The heartbeat monitoring module determines whether the controller is faulty by detecting whether the level of the heartbeat pulse signals received within two consecutive second set cycles changes. If the level of the heartbeat pulse signals received within two consecutive second set cycles changes, the controller is determined to be operating normally, and the main controller continues to send the first control command; if the level of the heartbeat pulse signals received within two consecutive second set cycles does not change, the controller is determined to be faulty, and the fault determination result of the controller is sent to the main controller, proceeding to step S13. Step S13: The main controller calculates and generates thyristor trigger pulse signals according to the real-time collected power grid operating parameters according to the first set cycle; Step S14: The heartbeat monitoring module determines that the controller continues to acquire heartbeat pulse signals after a fault. When the level of the heartbeat pulse signal received changes within two consecutive second set cycles, it determines that the controller has resumed normal operation and sends the determination result of the controller resuming normal operation to the main controller. The main controller then sends the first control command again and stops generating thyristor trigger pulse signals.

10. The control method for a thyristor-based power grid power regulation system according to claim 9, characterized in that, It also includes an adaptive bypass switching method based on operating conditions. This method is implemented after the power grid power regulation system is equipped with a bypass switching module. The controller that generates the thyristor trigger pulse signal between the main controller and the slave controller is the controller with control authority. The adaptive bypass switching method based on operating conditions includes the following steps: Step S21: The controller with control compares the real-time current of the back-end load with the set bypass switching threshold. When the real-time current of the back-end load is less than the bypass switching threshold for a period of time exceeding the first set time threshold, it is determined to be a small load or no-load condition. The controller with control stops generating thyristor trigger pulse signals, delays for the first set delay time, and then controls the bypass switching module to close, so that the grid current directly supplies power to the load through the bypass switching module. Step S22: In bypass direct-through mode, the controller with control continues to acquire the real-time current of the downstream load and compares the acquired real-time current of the downstream load with the set voltage regulation recovery threshold. When the real-time current of the downstream load is greater than the voltage regulation recovery threshold, the controller with control identifies whether there is an inductive load in the downstream load. If there is no inductive load, it is directly determined that the downstream load has recovered to normal, and the controller with control controls the bypass switching module to disconnect. After a second set delay time, the controller with control resumes generating the thyristor trigger pulse signal. If there is an inductive load, when the time for the real-time current of the downstream load to be greater than the voltage regulation recovery threshold exceeds the second set time threshold, it is determined that the load has recovered to normal, and the controller with control controls the bypass switching module to disconnect. After a second set delay time, the controller with control resumes generating the thyristor trigger pulse signal. The voltage regulation recovery threshold is greater than the bypass switching threshold.

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