A low-wind-speed self-lifting voltage-boosting wide-input charging control method and system for a hundred-watt-level vertical-axis wind turbine

Abstract

The present application relates to the technical field of small wind power generation and energy storage control, and provides a low-wind-speed self-lifting voltage-increasing wide-input charging control method and system for a hundred-watt-level vertical axis wind turbine, which comprises the following steps: a low-voltage wake-up state is established to provide initial working power for a main control unit, a gate drive unit and the like; an intermediate bus capacitor is charged in a current-limiting manner, and the pre-charging is exited after the bus voltage reaches a preset threshold; a power conversion unit is driven to operate to charge a battery pack; when the rectifier-side voltage is in a low-voltage region, a joint control of limiting duty ratio, limiting current and limiting duty ratio change rate is adopted to expand the charging interval; dynamic large-current charging under source power limitation is performed; the battery pack voltage is stabilized after reaching an absorption threshold, and the floating maintenance state is entered when the absorption end condition is met; the floating charging voltage is maintained, and the large-current charging is switched back when the voltage falls back to a re-charging threshold. The method realizes the overall control of low-voltage start-up, weak-wind charging, wide-input adaptation and phase-coupled charging.

Description

Technical Field

[0001] This invention relates to the field of small-scale wind power generation and energy storage control technology, specifically to a low-wind-speed self-bootstrapping voltage boosting wide-input charging control method and system for 100-watt vertical axis wind turbines. Background Technology

[0002] In existing small vertical axis wind power systems, a common structure is a wind turbine driving a permanent magnet generator. The generator output is directly connected to a battery bank or DC bus after three-phase rectification. While this type of system is simple in structure, in actual operation, the lack of dynamic matching between the wind turbine's aerodynamic characteristics, the generator's internal resistance, the rectified voltage drop, and the battery bank's terminal voltage often prevents the system from operating at its optimal energy transfer state across most wind speed ranges. For a nominal 24-volt energy storage system, if the rectified voltage is only 13 to 14 volts at low wind speeds, traditional controllers without a boost module or only capable of operating in the high-voltage zone cannot enter the normal charging range. This is especially true when the battery bank is in a higher voltage state before or after absorption or float charging, making it more likely to experience a situation where "it can generate electricity but cannot charge," resulting in long-term waste of low-wind-speed energy.

[0003] While some existing small wind turbine controllers are equipped with boost modules, they often focus on conventional voltage regulation output and fail to address the coordination between low-voltage self-starting, power supply bootstrapping, intermediate bus pre-charging, and input slump suppression. This is particularly problematic in small vertical axis wind turbines, where the rotor's starting torque is limited, mechanical energy storage is small, and the equivalent source impedance on the rectifier side varies significantly. If the controller blindly applies load in the low-voltage region, it can easily cause a rapid drop in rectified voltage, rotor stagnation, and system power failure, leading to an ineffective cycle of repeated wake-up, power failure, and re-wake-up.

[0004] Furthermore, existing charging control systems typically treat energy harvesting from the source side and the battery charging phase separately. Specifically, during the high-current constant-current charging phase, the controller often excessively pursues a rapid response of the battery-side charging current, neglecting the non-collapse constraint on the wind turbine input side. During the absorption and float charging phases, it may maintain high dynamic regulation in the upstream stage, causing unnecessary power fluctuations and device switching losses. Therefore, simply adding a boost converter stage cannot fundamentally solve the energy capture and stable charging problems of small vertical axis wind turbines in low-wind-speed, wide-input, and 24-volt battery pack charging scenarios. Therefore, there is an urgent need to construct a complete control method that couples the low-voltage wake-up to the stage charging process. Summary of the Invention

[0005] To address the problems existing in the background technology, this invention proposes a low-wind-speed self-lifting voltage boosting wide-input charging control method and system for 100-watt vertical axis wind turbines. It achieves overall control that enables low-voltage start-up, weak-wind charging, wide-input adaptability, and staged charging coupling. It is particularly suitable for coreless disc permanent magnet generators and similar low-voltage, high-current small wind turbine systems, and has strong engineering practicality.

[0006] To achieve the above objectives, the present invention adopts the following solution: A low-wind-speed self-boosting wide-input charging control method for 100-watt vertical axis wind turbines includes the following steps: Step 1: In the low-voltage wake-up state, the main control unit monitors the rectifier side voltage. When the rectifier side voltage meets the preset wake-up conditions, it controls the auxiliary bootstrap power supply unit to start and establish the initial working power supply for the main control unit, gate drive unit and sampling circuit. Step 2: After the main control unit is started, it controls the intermediate bus pre-charge unit to charge the intermediate bus capacitor in a current-limited manner, so that the intermediate bus capacitor rises to the preset working threshold, and then closes or exits the pre-charge path. Step 3: The main control unit drives the power conversion unit to start operation through the gate drive unit and begins charging the battery pack. Step 4: When the rectifier side voltage is still in the low voltage region, it enters the low voltage expansion state. The main control unit uses the rectifier side voltage not to collapse as a hard constraint and adopts the joint control of limiting duty cycle, limiting current and limiting duty cycle change rate to expand the low voltage range into a sustainable charging range. Step 5: When the power supply on the rectifier side is enhanced and the voltage on the battery pack side is lower than the absorption threshold, the system switches to a high-current charging state. The main control unit performs joint adjustment based on the power supply capacity on the rectifier side and the allowable charging current of the battery pack to execute dynamic high-current charging with limited source power. Step 6: When the battery pack side voltage reaches the absorption threshold, it enters the absorption charging state, and the main control unit maintains the battery pack side voltage near the absorption threshold; when the absorption end condition is met, it enters the float charging maintenance state. Step 7: In the float charging maintenance state, the main control unit maintains the battery pack near the float charging voltage; when the battery pack side voltage drops back to the recharge threshold, it switches back to the high current charging state.

[0007] Optionally, in step 1, the preset wake-up conditions include: the rectifier side voltage is higher than the set wake-up threshold, and the duration reaches the threshold.

[0008] Optionally, in step 4, it is checked whether any of the following collapse conditions are met. If so, the protection action of reducing the duty cycle, reducing the peak current, or entering the freeze cycle is immediately executed: ;or ;or ; In the formula, V rk It is the first k The rectifier-side voltage detected in each sampling cycle; V rk-1 It is the first k-1 The rectifier-side voltage detected in each sampling cycle; ΔV drop The threshold value for the allowable drop in input voltage is set, and it is a positive number. K collapse This is the threshold for the rate of decrease of the input voltage, and it is a positive number.

[0009] Optionally, in the low-voltage window expansion state of step 4, the drive is applied in a pulse envelope manner, the duty cycle is gradually increased within the working window, and the recovery of the rectifier side voltage is monitored within the intermittent window.

[0010] Optionally, in step 5, under the high-current charging state, the rectifier-side power or its proxy quantity is used as the adjustment benchmark, and the battery pack's allowable charging current is used as the upper limit for joint adjustment; when a single current sampling structure is adopted, the battery pack-side power proxy quantity is used as the optimization reference in the stage control; during the adjustment process, when the current extractable power of the rectifier side meets the charging target, charging is performed according to the set high-current charging target; when the rectifier side power supply is insufficient, the charging current target is automatically reduced so that the rectifier-side power is not excessively extracted; the low-voltage window expansion stage still uses the rectifier-side voltage not collapsing as a hard constraint.

[0011] Optionally, when the power conversion unit adopts a synchronous boost topology, the main control quantity is the boost duty cycle; when the power conversion unit adopts a non-reverse buck-boost topology, the main control quantity includes mode selection and in-mode duty cycle, and also includes topology compatibility control steps. Based on the comparison between the rectifier side voltage and the battery pack side voltage, select Boost mode, Buck-Boost mode, or Buck / Bypass mode; when the rectifier side voltage is lower than the battery pack side voltage, enter Boost mode; when the rectifier side voltage is close to the battery pack side voltage, enter Buck-Boost mode; when the rectifier side voltage is higher than the battery pack side voltage, enter Buck mode or bypass current limiting mode. A hysteresis interval is set at the mode switching boundary to prevent frequent and repeated mode switching.

[0012] Optionally, it also includes a protection shutdown procedure: when protection triggering conditions such as overvoltage, overcurrent, bus abnormality, overheating, reverse connection, short circuit, or continuous insufficient air supply input are detected, the main control unit shuts down the power conversion unit and retains the monitoring circuit; when the protection conditions return to normal and the re-wake-up conditions are met, it re-enters the low-voltage wake-up state.

[0013] A low-wind-speed self-bootstrapping wide-input charging control system for 100-watt vertical axis wind turbines includes a wind turbine, a coreless disc permanent magnet AC generator, a rectifier interface, an intermediate bus pre-charge unit, an auxiliary self-bootstrapping power supply unit, a power conversion unit, an intermediate bus capacitor, a battery pack, a gate drive unit, a sampling unit, a main control unit, and a battery charging management unit. The output end of the wind turbine is connected to the power input end of the coreless disc permanent magnet AC generator; the three-phase AC output end of the permanent magnet AC generator is connected to the AC input end of the rectifier interface. The DC output terminal of the rectifier interface is connected to the energy input terminal of the auxiliary bootstrap power supply unit, the energy input terminal of the intermediate bus precharge unit, and the input side of the power conversion unit, respectively. The power supply output terminal of the auxiliary bootstrap power supply unit is connected to the power supply terminals of the main control unit and the gate drive unit, respectively. The control output terminal of the main control unit is connected to the control input terminal of the intermediate bus pre-charge unit; The intermediate bus capacitor is connected to the output side of the power conversion unit; the output side of the power conversion unit is connected to the power port of the battery pack via the intermediate bus capacitor; the control terminal of the power conversion unit is connected to the drive output terminal of the gate drive unit; and the control signal input terminal of the gate drive unit is connected to the signal output terminal of the main control unit. The sampling unit's input terminals are respectively connected to the DC output side of the rectifier interface, both ends of the intermediate bus capacitor, and the power port of the battery pack. The signal output terminal of the sampling unit is connected to the sampling signal input terminal of the main control unit; The detection port of the battery pack is connected to the sampling input of the battery charging management unit, and the battery charging management unit is bidirectionally connected to the main control unit. The main control unit has a built-in hierarchical state machine, which includes at least low-voltage wake-up, pre-charge / bootstrapping, low-voltage windowing, high-current charging, absorption charging, float charging maintenance, and protection shutdown states.

[0014] Optionally, the intermediate bus pre-charge unit is a controlled current-limited pre-charge unit, which draws power from the DC output side of the rectifier interface and receives the pre-charge control signal issued by the main control unit; the auxiliary bootstrap power supply unit can be implemented by using an oscillator plus a pulse transformer, a charge pump, an ultra-low voltage boost chip or an equivalent discrete circuit to establish the initial working power supply for the main control unit, the gate drive unit and the sampling circuit.

[0015] Optionally, the sampling unit acquires the rectifier-side voltage V. r , Rectifier side current I r Battery pack side voltage V b Intermediate bus voltage V bus and the battery pack side current I b .

[0016] The beneficial effects of this invention are as follows: First, by cooperating with the auxiliary bootstrap power supply unit and the intermediate bus pre-charge unit, this solution enables the main control unit to reliably establish a working power supply even when the rectifier side voltage is lower than the minimum operating voltage required for the normal operation of the power conversion unit, thus breaking through the limitation of the input starting voltage of the traditional 24-volt energy storage system.

[0017] Secondly, by setting a low-voltage expansion window state and combining it with pulse envelope boost control, this solution can safely transfer the low-voltage rectified energy that was originally unusable to the battery pack side under low wind speeds, significantly expanding the system's working wind speed range. By setting input collapse priority protection logic and monitoring the voltage drop rate and bus maintenance capability on the rectifier side in real time, the probability of small vertical axis wind turbines being dragged down by electrical loads in weak wind areas is significantly reduced.

[0018] Third, this solution achieves continuous and stable control throughout the entire process, from low-voltage wake-up, pre-charge / bootstrapping, low-voltage windowing, high-current charging, absorption charging to float charging maintenance, by deeply coupling the source-side wide input conversion with the stage charging of the battery pack.

[0019] In addition, this solution is particularly suitable for coreless disc permanent magnet generators and similar low-voltage, high-current small wind turbine systems, and has strong engineering applicability. Attached Figure Description

[0020] Figure 1 This is a flowchart of the control state machine in an embodiment of the present invention; Figure 2 This is a block diagram of the overall system structure in an embodiment of the present invention. Detailed Implementation

[0021] To make the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the given embodiments are merely one implementation method and do not represent all embodiments.

[0022] Example 1 This invention provides a low-wind-speed self-boosting wide-input charging control method for 100-watt vertical axis wind turbines, preferably applied to a 300-watt vertical axis wind turbine; such as Figure 1 The flowchart shown includes the following steps: Step 1: In low-voltage wake-up mode, the main control unit continuously monitors the rectifier-side voltage V. r When V r Above the wake-up threshold V wake_on And the duration reaches T wake When the main control unit determines that the air source meets the startup conditions, it controls the auxiliary bootstrap power supply unit to start. The purpose of setting the duration criterion is to avoid the instantaneous voltage spike at the beginning of rotation from falsely triggering the main control unit to power on. The auxiliary bootstrap power supply unit can be implemented using an oscillator plus a pulse transformer, a charge pump, an ultra-low voltage boost chip, or an equivalent discrete circuit to establish the initial operating power supply for the main control unit, the gate drive unit, and the sampling circuit.

[0023] Step 2, Pre-charge / Bootstaff State: After the auxiliary power supply is established, the system enters the pre-charge / bootstaff state. The main control unit controls the intermediate bus pre-charge unit to charge the intermediate bus capacitor in a current-limited manner, so that the intermediate bus voltage V... bus The threshold V rises to the point where the main control unit and gate drive unit can operate stably. bus_on If the power conversion unit is a synchronous boost topology, a controlled short-pulse conduction strategy can be preferred for the low-side switching devices to gradually build up the inductor current and bus voltage. If the power conversion unit is a Buck-Boost topology, current-limited charging can be performed on the output side or bus side by pre-charging. The core of the pre-charging stage is not to quickly increase the bus voltage, but to establish a sustainable closed-loop condition without dragging down the rectifier input. When the intermediate bus voltage V... bus Reaching the preset working threshold V bus_on Then, close or exit the precharge path.

[0024] Step 3: After pre-charging is completed, the main control unit outputs a control signal to the power conversion unit through the gate drive unit, driving the power conversion unit to officially start operation and begin charging the battery pack.

[0025] Step 4, Low-pressure window expansion state: When the system detects V bus When the operating conditions are met and the rectifier-side voltage is still in the low-voltage region, it enters the low-voltage window expansion state. This state uses a limited duty cycle D. lim Current limit I lim and duty cycle change rate d D / d tJoint constraint control. The main control unit applies power stage drive in a pulse envelope manner, that is, gradually increasing the duty cycle within a short working window, and observing V within an intermittent window. r Recovery status. Check if any of the following collapse conditions are met. If so, immediately execute commands to reduce duty cycle, reduce peak current, or enter freeze cycle N. f Protective actions: ;or ;or ; In the formula, V rk It is the first k The rectifier-side voltage detected in each sampling cycle; V rk-1 It is the first k-1 The rectifier-side voltage detected in each sampling cycle; ΔV drop The threshold value for the allowable drop in input voltage is set, and it is a positive number. K collapse The input voltage drop rate threshold is a positive number. In this way, the low-voltage window state does not aim for the instantaneous maximum boost capacity, but prioritizes "maintaining sustainability at the source and ensuring uninterrupted power supply to the system," which can gradually push low rectified energy of thirteen to fourteen volts into the twenty-four-volt battery pack.

[0026] Step 5, High-current charging state: When the rectifier side's power supply capability is enhanced, and the battery pack side voltage V b When the voltage drops below the absorption threshold Vabs, the system switches to a high-current charging state. In this state, the main control unit replenishes energy to the battery pack with a large charging current. As the state of charge of the battery pack increases, the terminal voltage of the battery pack gradually rises. The main control unit then adjusts the charging current based on the rectifier-side power handling capacity and the upper limit of the battery pack's allowable charging current I. max Joint regulation should be carried out.

[0027] Among them, rectifier side power P in,k Defined as: ; In the formula, P in，K V represents the rectifier-side power corresponding to the Kth sampling period; r,k It is the rectifier-side voltage detected in the kth sampling period; I r,k It is the rectifier-side current detected in the kth sampling period; When using a single current sampling structure, the power surcharge on the battery pack side can also be used as an optimization reference in stage control. However, during the low-voltage windowing stage, the constraint of preventing voltage collapse on the rectifier side should still be considered. The power surcharge on the battery pack side is defined as follows: ; This represents the battery pack power corresponding to the kth sampling period; The battery pack side voltage detected in the kth sampling period; This represents the battery pack side current detected in the kth sampling period.

[0028] The following charging given logic is preferred: If P in,k If the available power allows, charging will proceed according to the set high-current charging target; if the rectifier-side power supply is insufficient, the charging current target will be automatically reduced to meet the system's requirements. P in,k It is not over-extracted. In other words, this embodiment does not perform fixed-current charging during the high-current charging phase, but rather performs dynamic high-current charging with limited source power. From the perspective of the electrical characteristics of the charging process, the high-current charging phase is mainly used to quickly restore the battery pack capacity. At this time, the charging current is relatively large, and the voltage on the battery pack side gradually increases with the increase of the charged energy.

[0029] Step 6, Absorbing charging state: When V is detected b Reaching the absorption threshold V abs Afterwards, the system switches to the absorption charging state. In this state, the control objective switches to maintaining the battery pack side voltage at V. abs Nearby, constant voltage control or current-limiting constant voltage control can be used. During the absorption and charging phase, the main control unit maintains a relatively high charging voltage, while the charging current continuously decreases as the battery pack gradually fills. When the absorption and charging duration reaches T... abs Or the battery pack side current I b Descending to the wake threshold I tail At this time, the system switches to float charge maintenance state.

[0030] Step 7, Float Charge Maintenance: In float charge mode, the main control unit maintains the battery pack at a lower float charge voltage V. float Nearby, a smaller charging current is used for long-term maintenance to reduce the risk of overcharging. During the float charging phase, only a small current is used to maintain the battery pack voltage to compensate for self-discharge and maintain charge over a long period. When the battery pack is idle or under load, causing the voltage to drop to the recharge threshold V, rebulk At that time, the system switches back to high-current charging mode.

[0031] By switching between the three stages of high-current charging, absorption charging, and float charging, a complete charging management process from rapid energy replenishment to stable maintenance can be achieved. Through the above-mentioned charging stage management, the main control unit is compatible with valve-regulated sealed lead-acid batteries and other energy storage batteries configured through parameter tables.

[0032] Regarding protection shutdown, if overvoltage, overcurrent, bus abnormality, device overtemperature, reverse connection, short circuit, or persistent insufficient fan input is detected, the system shuts down the main power stage while retaining necessary monitoring circuits. If conditions return to normal and the wake-up criteria are met, the main control unit can re-enter the low-voltage wake-up state. To improve field adaptability, various thresholds in the main control unit, including V... wake_on V bus_on V collapse V abs V float V rebulk T abs and I tail All parameters can be given by the parameter table and do not constitute a limitation on the present invention.

[0033] Example 2 Based on the method described in Embodiment 1, such as Figure 2 The system structure diagram shown in this embodiment provides a low wind speed self-lifting voltage boosting wide input charging control system for 100-watt vertical axis wind turbines. The wind turbine drives a coreless disc permanent magnet AC generator to generate electricity, and the generator output is rectified and then enters the controller input terminal.

[0034] The system includes a wind turbine, a coreless disc-type permanent magnet AC generator, a rectifier interface, an auxiliary self-bootstrapping power supply unit, an intermediate bus pre-charge unit, a power conversion unit, an intermediate bus capacitor, a battery pack, a gate drive unit, a sampling unit, a main control unit, and a battery charging management unit.

[0035] Specifically, the output end of the wind turbine is connected to the power input end of the coreless disc permanent magnet AC generator; the three-phase AC output end of the permanent magnet AC generator is connected to the AC input end of the rectifier interface. The rectifier interface can adopt an uncontrolled rectifier bridge, a synchronous rectifier bridge, or other low-dropout rectification methods. Under low wind speed and low voltage conditions, a low-dropout rectification method is preferred to reduce front-end conduction losses. The rectified output is connected to the auxiliary bootstrap power supply unit on one hand and to the input end of the power conversion unit on the other. The DC output end of the rectifier interface is connected to the energy input end of the auxiliary bootstrap power supply unit, the energy input end of the intermediate bus pre-charge unit, and the input side of the power conversion unit, respectively.

[0036] Specifically, the power supply output terminal of the auxiliary bootstrap power supply unit is connected to the power supply terminals of the main control unit and the gate drive unit, respectively. The auxiliary bootstrap power supply unit is used to supply power to the rectifier side voltage V when the system starts up. r Reaching the wake-up threshold V wake_on And the duration reaches T wakeAt that time, an initial operating power supply is established for the main control unit, gate drive unit, and sampling circuit through an oscillator, pulse transformer, charge pump, ultra-low voltage boost chip, or equivalent discrete circuit. The wake-up threshold V... wake_on The voltage is lower than the minimum operating voltage required for the power conversion unit to operate normally.

[0037] Specifically, the control output terminal of the main control unit is connected to the control input terminal of the intermediate bus pre-charge unit. After the main control unit is powered on, it sends a pre-charge control signal to the intermediate bus pre-charge unit. The intermediate bus capacitor is connected to the output side of the power conversion unit. The output side of the power conversion unit is connected to the power port of the battery pack via the intermediate bus capacitor.

[0038] Specifically, the control terminal of the power conversion unit is connected to the drive output terminal of the gate drive unit. The control signal input terminal of the gate drive unit is connected to the signal output terminal of the main control unit. The main control unit outputs a control signal to the power conversion unit through the gate drive unit, driving the power conversion unit to start operation. The power conversion unit adopts a buck-boost topology, specifically a synchronous boost topology or a non-reverse synchronous Buck-Boost topology. When the power conversion unit adopts a synchronous boost topology, the main control quantity is the boost duty cycle; when the power conversion unit adopts a non-reverse buck-boost topology, the main control quantity includes mode selection and duty cycle within the mode, and also includes a topology-compatible control step: based on the comparison result between the rectifier side voltage and the battery pack side voltage, select Boost mode, Buck-Boost mode, or Buck / bypass mode; wherein, when the rectifier side voltage is lower than the battery pack side voltage, enter Boost mode; when the rectifier side voltage is close to the battery pack side voltage, enter Buck-Boost mode; when the rectifier side voltage is higher than the battery pack side voltage, enter Buck mode or bypass current limiting mode; a hysteresis interval is set at the mode switching boundary to prevent high-frequency repeated mode switching.

[0039] Specifically, the control output terminal of the main control unit is connected to the gate drive unit, outputting PWM / enable / mode control signals to the gate drive unit. The sampling input terminal of the sampling unit is connected to the DC output side of the rectifier interface, both ends of the intermediate bus capacitor, and the power port of the battery pack. The signal output terminal of the sampling unit is connected to the sampling signal input terminal of the main control unit. In this embodiment, the main control unit prioritizes sampling the rectifier side voltage V. r , Rectifier side current I r Battery pack side voltage V b Intermediate bus voltage V bus and the battery pack side current I b .

[0040] Specifically, the detection port of the battery pack is connected to the sampling input of the battery charging management unit. The battery charging management unit is bidirectionally signal-connected to the main control unit. The main control unit has a built-in hierarchical state machine, which includes at least the following states: low-voltage wake-up, pre-charge / bootstrapping, low-voltage windowing, high-current charging, absorption charging, float charging maintenance, and protection shutdown. The main control unit uses this hierarchical state machine to switch between states, thereby controlling the transition from low-voltage wake-up to staged charging.

[0041] In summary, the method in this invention includes: establishing an initial working power supply for the main control unit, gate drive unit, etc., in a low-voltage wake-up state; current-limited charging of the intermediate bus capacitor, exiting pre-charging after the bus voltage reaches a preset threshold; driving the power conversion unit to charge the battery pack; when the rectifier side voltage is in the low-voltage region, using combined control of limiting duty cycle, current, and duty cycle change rate to expand the charging range; when the rectifier side power supply is enhanced and the battery pack side voltage is lower than the absorption threshold, joint adjustment is performed based on the rectifier side power supply capacity and the battery pack's allowable charging current to execute dynamic high-current charging under limited source power; after the battery pack voltage reaches the absorption threshold, it is stabilized, and if the absorption termination condition is met, it switches to a float charging maintenance state; the float charging voltage is maintained, and when the voltage drops back to the charging threshold, it switches back to high-current charging. This method, through the collaborative design of various structures, achieves overall control that allows for low-voltage start-up, charging in weak winds, wide input adaptability, and coupled stage charging.

[0042] The specific embodiments of the present invention have been described in detail above with reference to the figures, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and these variations still fall within the protection scope of the present invention.

Claims

1. A low-wind-speed self-boosting wide-input charging control method for 100-watt vertical axis wind turbines, characterized in that, Includes the following steps: Step 1: In the low-voltage wake-up state, the main control unit monitors the rectifier side voltage. When the rectifier side voltage meets the preset wake-up conditions, it controls the auxiliary bootstrap power supply unit to start and establish the initial working power supply for the main control unit, gate drive unit and sampling circuit. Step 2: After the main control unit is started, it controls the intermediate bus pre-charge unit to charge the intermediate bus capacitor in a current-limited manner, so that the intermediate bus capacitor rises to the preset working threshold, and then closes or exits the pre-charge path. Step 3: The main control unit drives the power conversion unit to start operation through the gate drive unit and begins charging the battery pack. Step 4: When the rectifier side voltage is still in the low voltage region, it enters the low voltage expansion state. The main control unit uses the rectifier side voltage not to collapse as a hard constraint and adopts the joint control of limiting duty cycle, limiting current and limiting duty cycle change rate to expand the low voltage range into a sustainable charging range. Step 5: When the power supply on the rectifier side is enhanced and the voltage on the battery pack side is lower than the absorption threshold, the system switches to a high-current charging state. The main control unit performs joint adjustment based on the power supply capacity on the rectifier side and the allowable charging current of the battery pack to execute dynamic high-current charging with limited source power. Step 6: When the battery pack side voltage reaches the absorption threshold, it enters the absorption charging state, and the main control unit maintains the battery pack side voltage near the absorption threshold; when the absorption end condition is met, it enters the float charging maintenance state. Step 7: In the float charging maintenance state, the main control unit maintains the battery pack near the float charging voltage; when the battery pack side voltage drops back to the recharge threshold, it switches back to the high current charging state.

2. The low-wind-speed self-lifting voltage boosting wide-input charging control method for 100-watt vertical axis wind turbines according to claim 1, characterized in that: In step 1, the preset wake-up conditions include: the rectifier side voltage is higher than the set wake-up threshold, and the duration reaches the threshold.

3. The low-wind-speed self-lifting voltage boosting wide-input charging control method for 100-watt vertical axis wind turbines according to claim 1, characterized in that: In step 4, it is checked whether any of the following collapse conditions are met. If so, the protection action of reducing the duty cycle, reducing the peak current command, or entering the freeze cycle is immediately executed: ;or ;or ; In the formula, V rk It is the first k The rectifier-side voltage detected in each sampling cycle; V rk-1 It is the first k-1 The rectifier-side voltage detected in each sampling cycle; ΔV drop The threshold value for the allowable drop in input voltage is set, and it is a positive number. K collapse This is the threshold for the rate of decrease of the input voltage, and it is a positive number.

4. The low-wind-speed self-boosting voltage boosting wide-input charging control method for 100-watt vertical axis wind turbines according to claim 3, characterized in that: In step 4, under the low-voltage expansion window state, the drive is applied in a pulse envelope manner, the duty cycle is gradually increased within the working window, and the recovery of the rectifier side voltage is monitored within the intermittent window.

5. The low-wind-speed self-boosting voltage boosting wide-input charging control method for 100-watt vertical axis wind turbines according to claim 1, characterized in that: In step 5, under the high-current charging state, the rectifier-side power or its proxy quantity is used as the adjustment benchmark, and the battery pack's allowable charging current is used as the upper limit for joint adjustment; when a single current sampling structure is used, the battery pack-side power proxy quantity is used as the optimization reference in the stage control. During the adjustment process, when the current extractable power on the rectifier side meets the charging target, charging is performed according to the set high current charging target; when the power supply on the rectifier side is insufficient, the charging current target is automatically reduced so that the power on the rectifier side is not excessively extracted; the low-voltage windowing stage still takes the rectifier side voltage not collapsing as a hard constraint.

6. The low-wind-speed self-bootstrapping wide-input charging control method for 100-watt vertical axis wind turbines according to claim 1, characterized in that: When the power conversion unit adopts a synchronous boost topology, the main control quantity is the boost duty cycle; when the power conversion unit adopts a non-reverse buck-boost topology, the main control quantity includes mode selection and duty cycle within the mode, and also includes topology compatibility control steps. Based on the comparison between the rectifier side voltage and the battery pack side voltage, select Boost mode, Buck-Boost mode, or Buck / Bypass mode; when the rectifier side voltage is lower than the battery pack side voltage, enter Boost mode; when the rectifier side voltage is close to the battery pack side voltage, enter Buck-Boost mode; when the rectifier side voltage is higher than the battery pack side voltage, enter Buck mode or bypass current limiting mode. A hysteresis interval is set at the mode switching boundary to prevent frequent and repeated mode switching.

7. The low-wind-speed self-lifting voltage boosting wide-input charging control method for 100-watt vertical axis wind turbines according to claim 1, characterized in that: It also includes a protection shutdown procedure: when overvoltage, overcurrent, bus abnormality, overheating, reverse connection, short circuit, or continuous insufficient air supply input protection trigger conditions are detected, the main control unit shuts down the power conversion unit and retains the monitoring circuit; when the protection conditions return to normal and the re-wake-up conditions are met, it re-enters the low-voltage wake-up state.

8. A low-wind-speed self-boosting wide-input charging control system for 100-watt vertical axis wind turbines, used to implement the method as described in any one of claims 1-7, characterized in that: It includes a wind turbine, a coreless disc-type permanent magnet AC generator, a rectifier interface, an intermediate bus pre-charge unit, an auxiliary self-bootstrapping power supply unit, a power conversion unit, an intermediate bus capacitor, a battery pack, a gate drive unit, a sampling unit, a main control unit, and a battery charging management unit. The output end of the wind turbine is connected to the power input end of the coreless disc permanent magnet AC generator; the three-phase AC output end of the permanent magnet AC generator is connected to the AC input end of the rectifier interface. The DC output terminal of the rectifier interface is connected to the energy input terminal of the auxiliary bootstrap power supply unit, the energy input terminal of the intermediate bus precharge unit, and the input side of the power conversion unit, respectively. The power supply output terminal of the auxiliary bootstrap power supply unit is connected to the power supply terminals of the main control unit and the gate drive unit, respectively. The control output terminal of the main control unit is connected to the control input terminal of the intermediate bus pre-charge unit; The intermediate bus capacitor is connected to the output side of the power conversion unit; the output side of the power conversion unit is connected to the power port of the battery pack via the intermediate bus capacitor; the control terminal of the power conversion unit is connected to the drive output terminal of the gate drive unit; and the control signal input terminal of the gate drive unit is connected to the signal output terminal of the main control unit. The sampling unit's input terminals are respectively connected to the DC output side of the rectifier interface, both ends of the intermediate bus capacitor, and the power port of the battery pack. The signal output terminal of the sampling unit is connected to the sampling signal input terminal of the main control unit; The detection port of the battery pack is connected to the sampling input of the battery charging management unit, and the battery charging management unit is bidirectionally connected to the main control unit. The main control unit has a built-in hierarchical state machine, which includes at least low-voltage wake-up, pre-charge / bootstrapping, low-voltage windowing, high-current charging, absorption charging, float charging maintenance, and protection shutdown states.

9. A low-wind-speed self-lifting voltage boosting wide-input charging control system for 100-watt vertical axis wind turbines according to claim 8, characterized in that: The intermediate bus pre-charge unit is a controlled current-limited pre-charge unit, which draws power from the DC output side of the rectifier interface and receives the pre-charge control signal issued by the main control unit; the auxiliary bootstrap power supply unit can be implemented by using an oscillator plus a pulse transformer, a charge pump, an ultra-low voltage boost chip or an equivalent discrete circuit to establish the initial working power supply for the main control unit, the gate drive unit and the sampling circuit.

10. A low-wind-speed self-lifting voltage boosting wide-input charging control system for 100-watt vertical axis wind turbines according to claim 8, characterized in that: The sampling unit acquires the rectifier-side voltage V. r , Rectifier side current I r Battery pack side voltage V b Intermediate bus voltage V bus and the battery pack side current I b .

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