Power wireless quasi-synchronization control method and wireless grid-connected system

Abstract

The application discloses a power wireless quasi-synchronization synchronization control method and a wireless grid-connected system. The method comprises the following steps: a power grid signal wireless collector broadcasts a power grid signal after detecting that commercial power is restored; an AP main machine generates and broadcasts a commercial power existence sign according to the power grid signal; an AP auxiliary machine obtains a unit side electric signal and returns the electric signal to the AP main machine; the AP main machine calculates voltage, frequency and phase difference and broadcasts the voltage, frequency and phase difference to each unit controller; the controller automatically adjusts a speed regulating device and a voltage regulating device to make parameters approach preset threshold values; when grid-connected conditions are met, synchronization locking is started and the phase difference is locked in a preset range; subsequently, the AP main machine sends a closing permission signal to a handheld wireless quasi-synchronization indicator; an operator manually closes a commercial power switch after seeing the prompt and confirms that the closing has been completed through a display; the AP main machine broadcasts the confirmation signal; and the AP auxiliary machine transmits the confirmation signal to the unit controller and the grid-connected controller, so that the unit exits locking and turns into a grid-connected operation mode.

Description

Technical Field

[0001] This application relates to the field of power grid connection control technology, and in particular to a power wireless quasi-synchronous control method and wireless grid connection system. Background Technology

[0002] During the grid connection operation of power systems, quasi-synchronous control is a core technology to ensure the safe and stable grid connection of generating units and the power grid. Its core requirement is to ensure that the voltage, frequency, and phase of the generating unit to be connected are consistent with those of the grid side, avoiding problems such as inrush current and unit oscillation caused by deviations in grid connection parameters, thereby protecting power equipment and ensuring the safe operation of the power grid. Currently, existing power grid connection control mostly uses wired communication to transmit parameters and exchange control commands, which suffers from complex wiring, high construction costs, and difficult maintenance. Especially in outdoor, remote areas, or temporary power supply scenarios, wired wiring is limited by geographical conditions and has extremely poor flexibility. Furthermore, in existing quasi-synchronous control, the status confirmation of the mains switch is mostly done through decentralized operations, which cannot achieve quasi-synchronous automatic control or grid connection status feedback. In addition, operators need to confirm the switch status on multiple unit controllers separately, which is cumbersome, inefficient, and prone to problems such as untimely status synchronization and misoperation, leading to delayed switching of unit operating modes and affecting grid connection stability and safety. Furthermore, existing quasi-synchronous control suffers from delays in the calculation and transmission of synchronization parameters, insufficient phase locking accuracy, and a tendency for phase differences to exceed limits during closing, leading to inrush currents and damage to generating units and grid equipment. Therefore, there is an urgent need for a method that can overcome these technical shortcomings and achieve wireless, centralized, and high-precision quasi-synchronous control. Summary of the Invention

[0003] In view of this, embodiments of this application provide a power wireless quasi-synchronous control method and a wireless grid-connected system.

[0004] According to one aspect of this application, a wireless quasi-synchronization control method for power systems is provided, applied to a wireless grid-connected system. The wireless grid-connected system includes a power generation unit, a wireless relay unit, a wireless grid signal collector, a mains switch, and a handheld wireless quasi-synchronization indicator. The wireless relay unit includes an access point (AP) host and a display. The power generation unit includes a speed control device, a voltage regulation device, a generator controller, a grid-connected controller, and an AP auxiliary unit. The method includes: After the power grid signal wireless collector detects that the mains power supply has been restored on the power grid power supply side, it broadcasts the collected power grid side electrical signal. The AP host receives the grid-side electrical signal, generates and broadcasts a mains power presence indicator signal; The AP auxiliary unit receives the mains power presence flag signal and acquires and sends the power signal to the unit side corresponding to the AP main generator; The AP host calculates the key parameter difference based on the received grid-side electrical signal and the generator-side electrical signal, and broadcasts the key parameter difference. The AP auxiliary machine transmits the received key parameter difference to the unit controller. The unit controller controls the speed regulation device and voltage regulation device to reduce the key parameter difference according to the key parameter difference. When the key parameter difference meets the requirements of the preset grid connection threshold, the synchronization locking function is activated and the synchronization locking signal is reported to the AP host. The synchronization locking function is used to lock the phase difference between the power generation device and the grid power supply within a preset range. After receiving the synchronization lock signal, the AP host sends a closing permission signal to the handheld wireless quasi-synchronization indicator. The handheld wireless quasi-synchronization indicator then displays a closing permission status prompt, allowing the operator to close the mains switch upon receiving the closing permission status prompt. After closing the mains switch, the operator inputs a confirmation signal indicating that the mains switch is closed via the display. The AP host then broadcasts the confirmation signal indicating that the mains switch is closed. The AP auxiliary machine transmits the confirmation signal that the mains switch has been closed to the unit controller and the grid connection controller respectively. The unit controller exits the synchronization lock function, and the grid connection controller switches the power generation unit to grid-connected operation mode.

[0005] In one optional embodiment, the AP host receives the grid-side electrical signal, generates and broadcasts a mains power presence indicator signal, including: The AP host receives the mains signal from the grid side, and when it determines that the mains voltage is within a preset normal range based on the mains signal, it generates and broadcasts a mains presence flag signal.

[0006] In one optional embodiment, the AP host calculates the key parameter difference based on the received grid-side electrical signal and the generator-side electrical signal, and broadcasts the key parameter difference, including: The AP host calculates the key parameter difference in real time based on the received grid-side electrical signals and generator-side electrical signals, and broadcasts the key parameter difference, which includes voltage difference, frequency difference, and phase difference.

[0007] In an optional embodiment, the method further includes: The AP host receives a confirmation signal from the operator indicating that the mains power switch has been disconnected via a display, and then broadcasts the confirmation signal. The AP auxiliary unit transmits a confirmation signal that the mains power switch has been disconnected to the grid-connected controller, which then switches the power generation unit to islanded load operation mode.

[0008] In one alternative embodiment, the timing for the operator to input a confirmation signal that the mains switch has been disconnected via the display includes mains maintenance after grid connection; the timing for the operator to input a confirmation signal that the mains switch has been closed via the display includes both first grid connection and second grid connection.

[0009] In one optional embodiment, the wireless relay unit further includes a protocol conversion module; the AP host broadcasts a confirmation signal that the mains switch has been closed, including: The AP host receives the confirmation signal that the mains switch has been closed. The protocol conversion module performs protocol conversion on the confirmation signal that the mains switch has been closed. The AP host then broadcasts the protocol-converted confirmation signal that the mains switch has been closed.

[0010] In one optional embodiment, the power generation device includes at least one; after receiving the synchronization lock signal, the AP host sends a closing permission signal to the handheld wireless quasi-synchronization indicator, including: After receiving the synchronization lock signals from all power generation devices, the AP host sends a closing permission signal to the handheld wireless quasi-synchronization indicator.

[0011] In an optional embodiment, the method further includes: The display shows the status of the grid-side electrical signal, the generator-side electrical signal corresponding to each power generation device, the key parameter difference, and the synchronization lock function.

[0012] In one optional embodiment, the preset range is -5° to 5°.

[0013] According to another aspect of this application, a wireless grid-connected system is provided for executing the above-described power wireless quasi-synchronous control method, comprising: The system includes at least one power generation device, a wireless relay unit, a grid signal wireless collector, a mains switch, and a handheld wireless quasi-synchronization indicator. The wireless relay unit includes an AP host, a protocol conversion module, and a display. Each power generation device is equipped with a speed control device, a voltage regulation device, a generator controller, a grid connection controller, and an AP auxiliary unit.

[0014] Using the above technical solution, the present application provides a power wireless quasi-synchronization control method and wireless grid-connected system. This method establishes a wireless network between a grid signal wireless collector and an AP host, collecting and broadcasting electrical signals from the grid side and each generating unit in real time. The AP host calculates the voltage difference, frequency difference, and phase difference and broadcasts this information to all unit controllers. The controllers automatically adjust speed and voltage regulation devices to synchronize the units with the grid within 10-30 seconds, locking the phase difference within ±5°. The operator only needs to manually close the mains power switch after receiving a "closing permission" prompt on the handheld wireless quasi-synchronization indicator. Then, the operator confirms "closed" on the integrated display of the wireless relay unit. The system then wirelessly broadcasts the synchronization, allowing all units to exit the lockout and enter grid-connected operation mode. Simultaneously, this method also supports mains power maintenance scenarios: after manual tripping, the operator confirms "disconnected" on the display, automatically switching all units to islanded operation with load, and supporting the entire secondary grid connection process after mains power is restored.

[0015] The beneficial effects of this method include: 1. Innovatively achieves wireless quasi-synchronous control, abandoning the traditional wired communication method. It constructs a wireless network through AP host, AP auxiliary unit and wireless communication module to realize the wireless transmission of synchronization parameters, control commands and status signals. No complicated wiring is required, reducing construction costs and maintenance difficulty, improving the flexibility of control method, and is suitable for outdoor, remote areas and temporary power supply scenarios. 2. A centralized status confirmation mechanism is adopted, with the wireless relay unit as the core of status confirmation. Operators only need to perform one operation to complete the status synchronization of all units, which solves the problems of cumbersome operation and untimely synchronization in the existing decentralized confirmation, improves operation efficiency and reduces the risk of misoperation. 3. Optimize the quasi-synchronous control process. The AP auxiliary machine calculates the synchronization parameters in real time, and the unit controller automatically adjusts the frequency and voltage. Combined with the built-in synchronization detection logic, high-precision phase locking is achieved (phase difference locked within ±5°, closing phase difference ≤3°), which effectively avoids the generation of inrush current, protects the unit and grid equipment, and improves grid connection stability and safety. 4. Clarify the timing for status confirmation of wireless relay units, covering key scenarios such as mains power maintenance and secondary grid connection, to ensure timely and accurate switching of unit operation modes, and to guarantee the continuity of power supply to the load and the reliability of grid operation; 5. The entire control method has a clear process and strong operability. The synchronous parameter calculation and transmission delay is low, and the status confirmation response is rapid. It can be widely used in the wireless grid-connected control of various power units (such as diesel generators, photovoltaic units, etc.) and has strong practicality and promotion value.

[0016] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0017] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 A flowchart illustrating a power wireless quasi-synchronous control method provided in an embodiment of this application is shown. Figure 2 A schematic diagram of the structure of a wireless network system provided in an embodiment of this application is shown. Detailed Implementation

[0018] The present application will be described in detail below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the present application can be combined with each other.

[0019] This embodiment provides a power wireless quasi-synchronous control method applied to a wireless grid-connected system. The wireless grid-connected system includes a power generation device, a wireless relay unit, a wireless grid signal collector, a mains switch, and a handheld wireless quasi-synchronous indicator. The wireless relay unit includes an access point (AP) host and a display. The power generation device includes a speed control device, a voltage regulation device, a generator controller, a grid-connected controller, and an AP auxiliary unit. Figure 1 As shown, the method includes: Step 101: After the power grid signal wireless collector detects that the mains power supply has been restored on the power grid power supply side, it broadcasts the collected power grid side electrical signal. Step 102: The AP host receives the grid-side electrical signal, generates and broadcasts a mains power presence indicator signal; Step 103: The AP auxiliary unit receives the mains power presence flag signal, acquires and sends the corresponding generator side electrical signal to the AP main unit generator; Step 104: The AP host calculates the key parameter difference based on the received grid-side electrical signal and the generator-side electrical signal, and broadcasts the key parameter difference. Step 105: The AP auxiliary machine transmits the received key parameter difference to the unit controller. The unit controller controls the speed regulation device and voltage regulation device to reduce the key parameter difference according to the key parameter difference. When the key parameter difference meets the requirements of the preset grid connection threshold, the synchronization locking function is activated and the synchronization locking signal is reported to the AP host. The synchronization locking function is used to lock the phase difference between the power generation device and the grid power supply within a preset range. Step 106: After receiving the synchronization lock signal, the AP host sends a closing permission signal to the handheld wireless quasi-synchronization indicator. The handheld wireless quasi-synchronization indicator provides a closing permission status prompt so that the operator can close the mains switch under the closing permission status prompt. After closing the mains switch, the operator inputs a confirmation signal that the mains switch has been closed through the display. The AP host broadcasts the confirmation signal that the mains switch has been closed. Step 107: The AP auxiliary machine transmits the confirmation signal that the mains switch has been closed to the unit controller and the grid connection controller respectively. The unit controller exits the synchronization lock function, and the grid connection controller switches the power generation unit to grid-connected operation mode.

[0020] In this embodiment, as Figure 2 As shown, 1-generator (e.g., diesel generator, one generator is used as an example in the figure), 2-wireless repeater unit, 3-speed control device, 4-voltage regulation device, 5-unit controller (e.g., DSEG8600 controller), 6-grid controller, 7-AP auxiliary unit, 8-AP host, 9-protocol conversion module, 10-grid load side, 11-mains switch (mains circuit breaker), 12-grid power supply side, 13-handheld wireless quasi-synchronization indicator, 14-grid electrical signal wireless collector. The wireless repeater unit consists of a protocol conversion controller, an AP host, and an integrated display (not shown in the figure). The AP host and the AP auxiliary units of each generator form a wireless network.

[0021] The specific process includes: when the mains power is restored on the power grid side, the grid power signal wireless collector (14) broadcasts the collected grid side voltage, frequency, and phase signals (with timestamps to ensure synchronization) through the wireless network. For example, the AP host receives the grid side electrical signal, generates and broadcasts the mains power presence flag signal, including: the AP host receives the grid side electrical signal, and when it is determined that the mains voltage is within the preset normal range based on the grid side electrical signal, it generates and broadcasts the mains power presence flag signal. Among them, after receiving these signals, the AP host (8) generates a "mains power presence" flag signal according to the preset normal range of mains power (such as 220V±10%), and broadcasts it to all AP auxiliary units (7) through the wireless network. After receiving the flag, the AP auxiliary unit obtains the voltage, frequency, phase, and other unit-side electrical signals of its own unit (generator) from the corresponding unit controller (5) through the CAN bus, and reports them to the AP host. For example, the AP host calculates the key parameter difference in real time based on the received grid-side electrical signals and the generator-side electrical signals, and broadcasts the key parameter difference, which includes voltage difference, frequency difference, and phase difference. The AP host calculates the key parameter difference (voltage difference ΔU, frequency difference Δf, phase difference Δφ) in real time based on the grid-side and generator-side signals, and broadcasts it to all AP auxiliary units at a period of no more than 0.5 seconds. The AP auxiliary units then transmit the parameter difference to their respective generator controllers, which automatically control the speed regulating device (3) and voltage regulating device (4) to gradually bring the generator voltage and frequency closer to the grid within 10 to 30 seconds. When ΔU, Δf, and Δφ all meet the preset grid connection thresholds (e.g., ΔU≤5%, Δf≤0.2Hz, Δφ≤10°), the generator controller activates the synchronization locking function, stabilizes the phase difference within ±5° by finely adjusting the generator speed through closed-loop control, and reports the locking signal to the AP host. For example, the power generation device includes at least one; after receiving the synchronization lock signal, the AP host sends a closing permission signal to the handheld wireless quasi-synchronization indicator, including: after receiving the synchronization lock signals of all power generation devices, the AP host sends a closing permission signal to the handheld wireless quasi-synchronization indicator. The AP host only sends a closing permission signal to the handheld wireless quasi-synchronization indicator (13) after receiving the lock signals of all units to be connected to the grid, and the indicator lights up the "closing permission" indicator. After seeing the prompt, the operator manually closes the mains switch (11) (at this time, since the phase is locked, the actual closing phase difference is ≤3°, and the inrush current is extremely small), and then walks to the integrated display of the wireless relay unit (2) and clicks to confirm "Mains switch is closed". For example, the wireless relay unit also includes a protocol conversion module; the AP host broadcasts the confirmation signal that the mains switch is closed, including: the AP host receives the confirmation signal that the mains switch is closed, the protocol conversion module performs protocol conversion on the confirmation signal that the mains switch is closed, and the AP host broadcasts the protocol-converted confirmation signal that the mains switch is closed.The confirmation signal is broadcast to all AP auxiliary units via the wireless network through the protocol conversion module (9) and the AP host, and then transmitted to the unit controller and grid controller (6) via the CAN bus. The unit controller immediately exits the synchronization lock, and the grid controller switches the power generation unit to the grid-connected operation mode (such as fixed power output), completing the entire wireless, centralized, and high-precision quasi-synchronous grid connection process.

[0022] In an optional embodiment, the method further includes: receiving a confirmation signal from an operator indicating that the mains power switch has been disconnected via a display; broadcasting the confirmation signal to the AP host indicating that the mains power switch has been disconnected; transmitting the confirmation signal to the grid-connected controller via the AP auxiliary unit; and switching the power generation unit to islanded load operation mode via the grid-connected controller.

[0023] In one alternative embodiment, the timing for the operator to input a confirmation signal that the mains switch has been disconnected via the display includes mains maintenance after grid connection; the timing for the operator to input a confirmation signal that the mains switch has been closed via the display includes both first grid connection and second grid connection.

[0024] In the above embodiments, after the power generation unit has successfully completed grid connection and is operating stably, if planned power outages such as mains line maintenance are required, the operator first manually disconnects the mains switch, and then inputs a confirmation signal of "Mains switch disconnected" through the integrated display of the wireless relay unit. This signal is then transmitted to the AP host via the protocol conversion module and broadcast by the AP host to all AP auxiliary units via the wireless network, and then transmitted to each grid-connected controller via the CAN bus. The grid-connected controller then controls the power generation unit to switch from grid-connected operation mode to islanded load-carrying operation mode, whereby the power generation unit independently undertakes the power supply for all loads, thereby safely isolating the mains side without interrupting the power supply to users. Correspondingly, the operator inputs a confirmation signal of "Mains switch closed" through the display, covering two situations: initial grid connection and secondary grid connection (reconnection after mains power is restored). During the first grid connection, the operator completes phase locking and manually closes the circuit breaker, then confirms the closing to initiate grid-connected operation. During the second grid connection, after mains maintenance is completed and power is restored, the generating unit remains in islanded mode. Synchronization adjustment and phase locking must be re-executed, and the operator manually closes the circuit breaker again and confirms the closing via the display, thus switching back from islanded mode to grid-connected operation mode. This design allows a single wireless quasi-synchronous control method to fully cover the entire lifecycle of "grid connection → mains maintenance disconnection → islanded operation → second grid connection after mains restoration." The operator only needs to complete one confirmation on the centralized display to synchronize the operating modes of all units, improving the automation and operational reliability of grid-connected control across multiple units and scenarios.

[0025] In one optional embodiment, the method further includes: displaying the status of the grid-side electrical signal, the generator-side electrical signal corresponding to each power generation device, the key parameter difference, and the synchronization lock function on the display.

[0026] This embodiment describes the centralized monitoring function of the integrated display in the wireless relay unit, which is the core of the human-machine interaction for the entire wireless quasi-synchronous control method. Specifically, the display presents real-time data such as grid-side voltage, frequency, and phase from the grid signal wireless acquisition device. Simultaneously, it displays the generator-side electrical signals (voltage, frequency, phase), key parameter differences (voltage difference ΔU, frequency difference Δf, phase difference Δφ), and the synchronization locking function status of each generator (e.g., "adjusting," "phase locked," "locked," "closing allowed") for each generator unit (e.g., "closing allowed"). Operators do not need to check each generator controller individually; they can centrally monitor the grid connection preparation progress and synchronization accuracy of all generator units on the wireless relay unit's display. When the parameter differences of all generator units meet the preset threshold and the status is displayed as "locked," the operator can safely proceed to the mains switch to manually close the circuit. In addition, the display is used to receive confirmation signals from operators indicating that the mains switch is closed or disconnected, and broadcasts these status commands to all units via the AP host, thus forming a visualized, centralized, and closed-loop control process. This design greatly improves the operational transparency and efficiency in multi-unit grid-connected scenarios, avoids status omissions or misjudgments caused by scattered viewing, and further ensures the safety and reliability of the grid connection process.

[0027] By applying the technical solution of this embodiment, a wireless network is constructed between the grid signal wireless collector and the AP host to collect and broadcast electrical signals from the grid side and each generating unit in real time. The AP host calculates the voltage difference, frequency difference, and phase difference and broadcasts them to all unit controllers. The controllers automatically adjust the speed and voltage regulation devices to synchronize the units with the grid within, for example, 10 to 30 seconds, and lock the phase difference within ±5°. After receiving the "closing permission" prompt on the handheld wireless quasi-synchronization indicator, the operator manually closes the mains power switch and then confirms "closed" on the integrated display of the wireless relay unit. The system then synchronizes all units through wireless broadcast to exit the lockout and enter grid-connected operation mode. At the same time, this method also supports mains power maintenance scenarios: after manually tripping the switch and confirming "disconnected" on the display, all units automatically switch to islanded load operation and support the entire process of secondary grid connection after mains power is restored.

[0028] The beneficial effects of this method include: 1. Innovatively achieves wireless quasi-synchronous control, abandoning the traditional wired communication method. It constructs a wireless network through AP host, AP auxiliary unit and wireless communication module to realize the wireless transmission of synchronization parameters, control commands and status signals. No complicated wiring is required, reducing construction costs and maintenance difficulty, improving the flexibility of control method, and is suitable for outdoor, remote areas and temporary power supply scenarios. 2. A centralized status confirmation mechanism is adopted, with the wireless relay unit as the core of status confirmation. Operators only need to perform one operation to complete the status synchronization of all units, which solves the problems of cumbersome operation and untimely synchronization in the existing decentralized confirmation, improves operation efficiency and reduces the risk of misoperation. 3. Optimize the quasi-synchronous control process. The AP auxiliary machine calculates the synchronization parameters in real time, and the unit controller automatically adjusts the frequency and voltage. Combined with the built-in synchronization detection logic, high-precision phase locking is achieved (phase difference locked within ±5°, closing phase difference ≤3°), which effectively avoids the generation of inrush current, protects the unit and grid equipment, and improves grid connection stability and safety. 4. Clarify the timing for status confirmation of wireless relay units, covering key scenarios such as mains power maintenance and secondary grid connection, to ensure timely and accurate switching of unit operation modes, and to guarantee the continuity of power supply to the load and the reliability of grid operation; 5. The entire control method has a clear process and strong operability. The synchronous parameter calculation and transmission delay is low, and the status confirmation response is rapid. It can be widely used in the wireless grid-connected control of various power units (such as diesel generators, photovoltaic units, etc.) and has strong practicality and promotion value.

[0029] In a specific application scenario, the execution process of the above method includes: Step 1: Detect mains power status and activate grid connection mode.

[0030] 1.1 During uninterrupted emergency power supply, after the mains power is restored on the grid power supply side, a secondary grid connection is required. To reduce the cabling involved in this process, this method uses a wireless approach. The wireless transmission signal is timestamped for signal synchronization. The wireless relay unit AP host in the system collects the mains power signal in real time through the grid power signal wireless collector. When the mains voltage is detected to be within the preset normal range, the AP host generates a mains power presence flag signal through the CAN bus controller and broadcasts the flag signal to all unit controllers in the system through the wireless network (composed of the AP host and each AP auxiliary unit). The signals are synchronized through timestamps throughout the entire process. 1.2 Based on the mains power presence indicator signal, the operator manually sets the controller of each unit to grid-connected mode, activates the quasi-synchronous control logic of the unit, and puts the unit into grid-connected preparation state.

[0031] Step 2: Calculation and transmission of wireless synchronization parameters.

[0032] 2.1 The AP auxiliary unit establishes a stable wireless communication connection with the AP main unit to collect electrical signals from the grid side and the generator side in real time (the grid side electrical signals are obtained through the grid electrical signal wireless collector, and the generator side electrical signals are obtained through the generator controller). 2.2 The AP host calculates key parameters for quasi-synchronous synchronization in real time based on the collected electrical signals, including voltage difference ΔU, frequency difference Δf, and phase difference Δφ. 2.3 The AP host will broadcast the calculated ΔU, Δf, and Δφ to the AP auxiliary unit via the wireless network, and the AP auxiliary unit will then transmit them to the unit controller via the CAN bus.

[0033] Step 3: Unit synchronization adjustment and phase locking.

[0034] 3.1 After receiving the synchronization parameters broadcast by the AP host, each unit controller, in conjunction with its own preset quasi-synchronization control threshold, automatically controls the speed control device to adjust the unit frequency and controls the voltage regulation device to adjust the unit voltage, so that the unit's voltage and frequency gradually synchronize with the mains power side. This frequency and voltage regulation process lasts for 10 to 30 seconds. 3.2 The unit controller has built-in synchronization detection logic to determine in real time whether the received ΔU, Δf, and Δφ meet the preset grid connection threshold. When all three meet the threshold requirements, the synchronization locking function is activated to lock the phase difference between the unit and the mains power within ±5°. The locking time can be flexibly configured according to actual operating requirements. 3.3 During the synchronization lock period, the operator holds a wireless quasi-synchronization indicator and checks the status at the mains switch. At this time, the "closing permission" indicator light on the indicator will be constantly lit, indicating to the operator that the closing operation can be performed. The operator does not need to pay attention to the slip direction, which reduces the difficulty of operation.

[0035] Step 4: Close the mains power switch and confirm its status.

[0036] 4.1 At any time when the phase is locked, the operator can manually close the mains circuit breaker (mains switch). Since the phase has been stably locked, the actual phase difference when closing is ≤3°, which effectively avoids the generation of inrush current. 4.2 After successful closing, the operator manually selects and confirms "Main power switch closed" on the integrated display of the wireless relay unit to complete the centralized confirmation of the main power switch status; 4.3 After receiving the status confirmation signal from the integrated display, the protocol conversion controller of the wireless relay unit sends the signal to the AP host via the CAN bus. The AP host immediately broadcasts the signal to all AP slaves via the wireless network. Each AP slave then sends the status command to the corresponding unit controller via the CAN bus. 4.4 After receiving the "mains switch closed" command, each unit controller immediately exits the synchronization lock function, switches to grid-connected operation mode, and outputs power in coordination with the mains power at a fixed power level.

[0037] Step 5: Centralized status confirmation mechanism for wireless relay units.

[0038] This method achieves centralized confirmation of the status of mains power switches through wireless relay units. Its core mechanism includes confirmation method, components, process, and timing, as detailed below: 5.1 Confirmation method.

[0039] The actual status (closed / open) of the mains-side circuit breaker directly determines the unit's operating mode: when the mains switch is open, the unit needs to switch from fixed power output to islanded load operation; when the mains switch is closed, the unit needs to switch to grid-connected operation mode, coordinating with the mains power output. This method uses a wireless relay unit as a centralized status confirmation point. Operators only need to perform a status confirmation operation once on the wireless relay unit to synchronize the status signal to all unit controllers via the wireless network, eliminating the need for distributed operations and improving operational efficiency and the accuracy of status synchronization.

[0040] 5.2 Composition of wireless relay unit.

[0041] The wireless repeater unit consists of a protocol conversion controller, an AP host, and an integrated display. The protocol conversion controller is connected to the AP host (main AP wireless communication module) via a CAN bus. The AP host, as the central node of the entire wireless network, is responsible for receiving the status confirmation signal from the integrated display and transmitting the signal to all AP auxiliary units via wireless broadcast. The integrated display is used by operators to input status confirmation commands and displays the current mains power switch status and system operating parameters in real time.

[0042] 5.3 Status Confirmation Process.

[0043] 5.3.1 On the integrated display interface, the operator selects the command "Main power switch is off" or "Main power switch is on" according to the actual status of the mains power switch (closed / open); 5.3.2 The integrated display sends the status commands input by the operator to the protocol conversion controller, which then transmits the commands to the AP host via the CAN bus; 5.3.3 After receiving the status command, the AP host immediately broadcasts it to all AP slaves in the system via the wireless network; 5.3.4 After receiving the broadcast status command, each AP auxiliary unit sends the command to the corresponding local controller (such as DSEG8600 or COMAP controller) via the CAN bus. 5.3.5 Each unit controller updates its internal operating logic based on the received status instructions: if it receives the instruction "the mains switch is open", the controller controls the unit to switch to island mode and perform island load operation; if it receives the instruction "the mains switch is closed", the controller controls the unit to switch to grid-connected operation mode and output in coordination with the mains power.

[0044] 5.4 When to confirm status.

[0045] 5.4.1 Timing of Mains Power Maintenance after Initial Grid Connection: After the generating unit has been connected to the mains power and is stably outputting a fixed power, if mains power maintenance is required, the operator should first manually disconnect the mains power switch, and then confirm "Mains power switch is disconnected" on the integrated display of the wireless relay unit. After receiving this status command, the controllers of each generating unit should immediately switch to islanded load operation mode to ensure the continuity of power supply to the load. 5.4.2 Preparation time before secondary grid connection: When the mains power is restored to normal and the unit has completed phase locking through step three, the operator manually closes the mains power switch and then confirms "mains power switch is closed" on the integrated display of the wireless relay unit. After receiving the status command, the controller of each unit exits the synchronization lock and switches to the grid-connected operation mode to complete the secondary grid connection.

[0046] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0047] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A method for quasi-synchronous control of power wireless circuits, characterized in that, The method is applied to a wireless grid-connected system, which includes a power generation unit, a wireless repeater unit, a wireless grid signal collector, a mains switch, and a handheld wireless quasi-synchronization indicator. The wireless repeater unit includes an access point (AP) host and a display. The power generation unit includes a speed control device, a voltage regulation device, a generator controller, a grid-connected controller, and an AP auxiliary unit. After the power grid signal wireless collector detects that the mains power supply has been restored on the power grid power supply side, it broadcasts the collected power grid side electrical signal. The AP host receives the grid-side electrical signal, generates and broadcasts a mains power presence indicator signal; The AP auxiliary unit receives the mains power presence flag signal and acquires and sends the power signal to the unit side corresponding to the AP main generator; The AP host calculates the key parameter difference based on the received grid-side electrical signal and the generator-side electrical signal, and broadcasts the key parameter difference. The AP auxiliary machine transmits the received key parameter difference to the unit controller. The unit controller controls the speed regulation device and voltage regulation device to reduce the key parameter difference according to the key parameter difference. When the key parameter difference meets the requirements of the preset grid connection threshold, the synchronization locking function is activated and the synchronization locking signal is reported to the AP host. The synchronization locking function is used to lock the phase difference between the power generation device and the grid power supply within a preset range. After receiving the synchronization lock signal, the AP host sends a closing permission signal to the handheld wireless quasi-synchronization indicator. The handheld wireless quasi-synchronization indicator then displays a closing permission status prompt, allowing the operator to close the mains switch upon receiving the closing permission status prompt. After closing the mains switch, the operator inputs a confirmation signal indicating that the mains switch is closed via the display. The AP host then broadcasts the confirmation signal indicating that the mains switch is closed. The AP auxiliary machine transmits the confirmation signal that the mains switch has been closed to the unit controller and the grid connection controller respectively. The unit controller exits the synchronization lock function, and the grid connection controller switches the power generation unit to grid-connected operation mode.

2. The method according to claim 1, characterized in that, The AP host receives the grid-side electrical signal, generates and broadcasts a mains power presence indicator signal, including: The AP host receives the mains signal from the grid side, and when it determines that the mains voltage is within a preset normal range based on the mains signal, it generates and broadcasts a mains presence flag signal.

3. The method according to claim 1, characterized in that, The AP host calculates the key parameter difference based on the received grid-side electrical signal and the generator-side electrical signal, and broadcasts the key parameter difference, including: The AP host calculates the key parameter difference in real time based on the received grid-side electrical signals and generator-side electrical signals, and broadcasts the key parameter difference, which includes voltage difference, frequency difference, and phase difference.

4. The method according to claim 1, characterized in that, The method further includes: The AP host receives a confirmation signal from the operator indicating that the mains power switch has been disconnected via a display, and then broadcasts the confirmation signal. The AP auxiliary unit transmits a confirmation signal that the mains power switch has been disconnected to the grid-connected controller, which then switches the power generation unit to islanded load operation mode.

5. The method according to claim 4, characterized in that, The timing for operators to input a confirmation signal that the mains power switch has been disconnected via the display includes mains power maintenance after initial grid connection; the timing for operators to input a confirmation signal that the mains power switch has been closed via the display includes both initial and secondary grid connection.

6. The method according to claim 1, characterized in that, The wireless repeater unit also includes a protocol conversion module; the AP host broadcasts a confirmation signal that the mains switch has been closed, including: The AP host receives the confirmation signal that the mains switch has been closed. The protocol conversion module performs protocol conversion on the confirmation signal that the mains switch has been closed. The AP host then broadcasts the protocol-converted confirmation signal that the mains switch has been closed.

7. The method according to any one of claims 1 to 6, characterized in that, The power generation device includes at least one; after receiving the synchronization lock signal, the AP host sends a closing permission signal to the handheld wireless quasi-synchronization indicator, including: After receiving the synchronization lock signals from all power generation devices, the AP host sends a closing permission signal to the handheld wireless quasi-synchronization indicator.

8. The method according to claim 7, characterized in that, The method further includes: The display shows the status of the grid-side electrical signal, the generator-side electrical signal corresponding to each power generation device, the key parameter difference, and the synchronization lock function.

9. The method according to any one of claims 1 to 6, characterized in that, The preset range is -5° to 5°.

10. A wireless network system, characterized in that, The method for performing power wireless quasi-synchronous control as described in any one of claims 1 to 9 includes: The system includes at least one power generation device, a wireless relay unit, a grid signal wireless collector, a mains switch, and a handheld wireless quasi-synchronization indicator. The wireless relay unit includes an AP host, a protocol conversion module, and a display. Each power generation device is equipped with a speed control device, a voltage regulation device, a generator controller, a grid connection controller, and an AP auxiliary unit.

Images