A multi-magnetic-core variable inductance control method based on light adjustment and application thereof

Abstract

This invention discloses a multi-core variable inductor control method based on illumination adjustment and its application in a boost converter. The method acquires real-time ambient light intensity information through an ambient light sensor and transmits the collected light data to a controller. The controller controls the excitation current of the control winding in the multi-core variable inductor according to a preset illumination threshold, thereby adjusting the equivalent inductance value of the variable inductor. By adjusting the inductance value, the boost converter dynamically switches between continuous conduction mode (CCM), boundary conduction mode (BCM), and discontinuous conduction mode (DCM) to adapt to different illumination conditions and load requirements. This method can improve the dynamic response capability, maximum power point tracking efficiency, and overall energy conversion efficiency of photovoltaic systems under different irradiance intensities, exhibiting good environmental adaptability and broad application prospects.

Description

Technical Field

[0001] This invention relates to the fields of power electronics and new energy technology, and in particular to a control method for a multi-magnetic-core segmented variable inductor (MCS-VI) based on illumination regulation and its application in a photovoltaic boost DC-DC power converter. Background Technology

[0002] In recent years, with the widespread deployment of photovoltaic power generation systems and their rapid development in distributed energy systems, the efficient operation and fast dynamic response of power converters have become a research hotspot. Traditional photovoltaic boost converters typically rely on fixed inductors or complex parallel inductor switching structures to achieve maximum power point tracking (MPPT) and output voltage regulation. However, under conditions of drastic fluctuations in solar irradiance or frequent changes in load conditions, the system response speed of fixed inductors is limited, and overall system efficiency is difficult to achieve simultaneously.

[0003] Existing variable inductor regulation methods mainly rely on magnetically controlled inductors (such as core saturation control and magnetically controlled material modulation) or multi-inductor switching methods. However, these methods generally suffer from problems such as complex structure, cumbersome control strategy, slow response and high cost, which limit their large-scale application in distributed photovoltaic systems.

[0004] Especially under dynamic lighting conditions, photovoltaic output power fluctuates frequently, and the inductor cannot be adjusted in real time, leading to problems such as decreased MPPT efficiency, increased power loss, and system instability, which urgently need to be addressed. Therefore, designing a variable inductor adjustment method that is fast-responding, simple in structure, and flexible in control has become an important direction for improving the performance of photovoltaic systems. Summary of the Invention

[0005] This invention discloses a variable inductor (MCS-VI) based on a multi-core structure and its application method in a light-adaptive photovoltaic boost system. The system can automatically adjust the inductance value in multiple levels according to changes in ambient light intensity, thereby driving the photovoltaic boost module to achieve optimal switching between continuous conduction mode (CCM), critical conduction mode (BCM), and intermittent conduction mode (DCM), improving the energy conversion efficiency and dynamic response capability of the photovoltaic system under strong, medium, and weak light conditions.

[0006] The core device of this invention is a multi-core variable inductor, the structure of which includes:

[0007] A main magnetic core segment is used to couple the main winding to achieve basic energy transmission.

[0008] At least two outer magnetic core segments (left and right) are wound with control windings to control whether the magnetic core enters saturation state through current excitation, thereby adjusting the total magnetic circuit reluctance and thus affecting the equivalent inductance value of the main winding.

[0009] The equivalent inductance value of the variable inductor of the present invention is determined by the parallel relationship of the reluctance of the main magnetic core and the outer magnetic core, and can be expressed as:

[0010] (1) Wherein:

[0011] N Number of turns in the main winding;

[0012] The main magnetic core section reluctance is affected by the permeability. control;

[0013] The reluctance of the outer magnetic core (composed of left and right magnetic cores) is controlled by whether or not it is saturated.

[0014] The outer magnetic core is used to divide the system into multiple inductance levels based on its saturation state:

[0015] If neither the left nor right magnetic core is saturated:

[0016] (2)

[0017] If only one side of the magnetic core is saturated:

[0018] (3)

[0019] If both the left and right magnetic cores are saturated:

[0020] (4)

[0021] The inductor is adjusted digitally to control the excitation current in the winding to be discrete 0A or 1A, that is:

[0022] (5)

[0023] This converts the inductance value into three stable levels, suitable for different light intensities.

[0024] This invention further proposes an illumination-adaptive inductor control method, comprising the following logical relationships:

[0025] (6)

[0026] in:

[0027] The current light intensity (lux) is measured by the light acquisition module;

[0028] L1>L2>L3 correspond to the inductor positions where both magnetic cores are saturated, one side is saturated, and both sides are unsaturated, respectively.

[0029] Through the above-mentioned equivalent inductance value switching, the inductor current of the photovoltaic Boost system... It can automatically adjust the waveform shape to achieve optimal operating conditions. Based on the Boost converter formula:

[0030] (7)

[0031] When L decreases As L increases, the system is more likely to enter DCM (inductor current is completely zero); as L increases, it tends to CCM (inductor current is continuously non-zero).

[0032] Therefore, the structure and method proposed in this invention have the following advantages:

[0033] First, the control strategy is intelligent and efficient, and can adaptively adjust the operating mode to improve the system stability and energy efficiency under different lighting conditions;

[0034] Second, the multi-core variable inductor structure is novel, with high adjustment precision, and achieves full electromagnetic control, eliminating the need for mechanical switching devices;

[0035] Third, the control current is a binary discrete quantity, which facilitates logic scheduling by the controller and results in a fast response speed.

[0036] In summary, this invention is innovative, practical, and has broad prospects for engineering application in the construction of photovoltaic intelligent voltage boosting systems. Attached Figure Description

[0037] To more clearly illustrate the technical solution of the present invention, the structure and control flow of the present invention will be further described below with reference to the accompanying drawings. The accompanying drawings are for illustrative purposes only and do not constitute any limitation on the present invention.

[0038] Figure 1 This is a schematic diagram of the structural connection between the multi-core variable inductor (MCS-VI) based on light intensity adjustment and the photovoltaic boost system of the present invention;

[0039] Figure 2 This is a control flowchart of the multi-core variable inductor based on changes in ambient light intensity in this invention;

[0040] Figure 3 This is a schematic diagram showing the correspondence between different lighting levels (such as cloudy, overcast, and sunny) and the working states of the multi-core variable inductor in this invention.

[0041] Figure 4This invention relates to the Boost inductor current waveform under different lighting conditions. The diagram illustrates the changes in conduction mode under the multi-core variable inductor control strategy. Detailed Implementation

[0042] This invention provides a multi-core variable inductor control method based on illumination adjustment, applied to photovoltaic boost systems. This method utilizes a multi-core variable inductor (MCS-VI) and dynamically adjusts the inductance value in conjunction with real-time changes in illumination intensity, thereby optimizing the performance of the photovoltaic system under different illumination conditions. Specifically, the system adjusts the core saturation state according to changes in external ambient illumination intensity to achieve multi-level adaptive adjustment of the inductance value, enabling the system to operate efficiently and stably under strong light, weak light, and moderate illumination conditions.

[0043] The core structure of the multi-core variable inductor includes a main core and multiple outer cores. The main core provides the basic inductance, while the outer cores are wound around a control winding. The current in the control winding is adjusted via a switch to change the saturation state of the outer cores, thereby altering the total inductance. Under low light conditions, the outer cores are unsaturated, resulting in a higher inductance; under strong light conditions, they are saturated, resulting in a lower inductance. Changes in light intensity are sensed in real time by a light acquisition module. The controller outputs corresponding control signals based on different light intensities, adjusting the control current to switch the saturation state of the cores, thus achieving automatic adjustment of the inductance.

[0044] Specifically, this invention employs a discrete current control strategy, whereby the current in the control winding switches only between 0A and 1A to drive the outer magnetic core into two operating states: saturated and unsaturated. When the control current is 0A, the outer magnetic core remains in a linear (unsaturated) state; when the control current is 1A, the outer magnetic core enters a saturated state, thereby achieving inductance adjustment. Through this simple and efficient control method, this invention significantly simplifies the inductance adjustment process, reduces the reliance on multiple MOS switches and complex control logic required in traditional systems, and lowers system hardware costs and control latency.

[0045] Under low-light conditions (such as cloudy days), the system ensures maximum inductance by keeping the outer magnetic core completely unsaturated, thus guaranteeing the photovoltaic system operates in CCM (Continuous Compactor Mode). In this mode, current flows continuously, the inductor current does not return to zero, and the system effectively reduces current fluctuations, ensuring system stability and continuous output. Under medium-light conditions (such as partly cloudy days), some of the outer magnetic core is saturated, the inductance value is moderate, and the system operates in BCM (Basic Compactor Mode). In this mode, the inductor current drops slightly to zero at the end of each cycle, adapting to changes in moderate light conditions, reducing energy loss, and improving conversion efficiency. Finally, under strong-light conditions (such as sunny days), the outer magnetic core is fully saturated, the inductance value drops to minimum, and the system operates in DCM (Digital Compactor Mode). In DCM mode, the inductor current returns to zero completely within each cycle, enabling faster response to rapidly changing light conditions, improving the system's dynamic performance and rapid adjustment capabilities.

[0046] In practical applications, the system adjusts the saturation state of the outer magnetic core based on real-time changes in light intensity, intelligently switching between different operating modes to ensure that the photovoltaic system is always in optimal working condition under varying lighting environments. The advantage of this method lies in the discrete control current, which simplifies the control loop, reduces the need for hardware switching frequency, and simultaneously improves response speed and control accuracy. By precisely adjusting the inductance value, the system can achieve optimal operating conditions under various lighting environments, avoiding efficiency losses caused by light fluctuations in traditional solutions, improving the MPPT efficiency of the photovoltaic system, and significantly reducing power fluctuations and improving system response speed, especially under complex environmental conditions.

[0047] Furthermore, the discretization of current control (0A and 1A) simplifies system control, reduces the need for high-frequency switching in traditional systems, lowers hardware complexity, and reduces system power consumption and cost. Discrete current switching ensures the simplicity and stability of the control signal, improving system reliability and long-term operational stability.

[0048] Experimental verification shows that the multi-core variable inductor control method based on adaptive light intensity control described in this invention can achieve rapid adjustment of the inductance value and switch to the corresponding operating mode according to different lighting conditions. Compared with the traditional method of using MOSFETs for inductor switching, this method has a simpler structure, more direct control, faster response characteristics, and higher operational stability. In actual testing, the system can successfully switch between continuous conduction mode, discontinuous conduction mode, and critical conduction mode under different lighting environments, demonstrating good dynamic adaptability and energy conversion efficiency. In this embodiment, the Boost power converter used operates at a frequency of 100kHz, with a duty cycle set to 75%, and the load is a resistive load. Under the above conditions, the system can achieve rapid switching control of the equivalent inductance value and stably complete the dynamic switching between CCM, DCM, and BCM, further verifying the feasibility and superiority of this method in multi-mode matching, and proving that this method has high practicality and application potential under complex lighting conditions.

[0049] In summary, the multi-core variable inductor control method based on adaptive light intensity regulation provided by this invention has significant technical advantages, can effectively improve the energy efficiency, response speed and stability of photovoltaic boost systems, and has good adaptability and efficiency in practical applications.

Claims

1. A multi-core variable inductor control method based on illumination adjustment, applicable to boost DC-DC power converter systems integrating multi-core variable inductors, characterized in that, The method includes: S1: Real-time acquisition of ambient light intensity data via a light sensor, and conversion of the data into a digital signal output; S2: The digital signal is transmitted to the controller, which divides the current light intensity into multiple levels according to a preset light intensity threshold range; S3: Based on the current light intensity level, the controller controls the excitation current of the control winding in the multi-core segment according to the light intensity level; S4: The excitation current acts on the control windings of different peripheral magnetic core segments, causing them to enter a magnetic saturation state or remain in the linear region, thereby changing the magnetic circuit structure and equivalent inductance value of the multi-core variable inductor. S5: Based on the change in the equivalent inductance value, guide the boost DC-DC power converter system to automatically switch between continuous conduction mode (CCM), boundary conduction mode (BCM), and discontinuous conduction mode (DCM); S6: Through the dynamic adjustment of the above conduction mode, the energy transmission efficiency of the boost DC-DC power converter system is optimized and the maximum power point tracking (MPPT) performance is improved under different lighting conditions and load fluctuations.

2. The method for controlling a multi-core variable inductor based on illumination adjustment according to claim 1, characterized in that, The light sensor is a digital light module with an I²C interface, and the controller is a microcontroller with PWM control function.

3. The method for controlling a multi-core variable inductor based on illumination adjustment according to claim 1, characterized in that, The multi-core variable inductor includes: A central magnetic core segment is equipped with a main winding for power transmission; At least two outer core segments, each with an independent control winding, and using magnetic materials with different permeabilities.

4. The method for controlling a multi-core variable inductor based on illumination adjustment according to claim 1, characterized in that, The material of the outer magnetic core segment is an easily saturated magnetic powder core or a ferrite core.

5. The method for controlling a multi-core variable inductor based on illumination adjustment according to claim 1, characterized in that, The light intensity levels are divided into strong light zone, medium light zone and weak light zone, which correspond to the discontinuous conduction mode, boundary conduction mode and continuous conduction mode of the boost DC-DC power converter system, respectively.

6. The method for controlling a multi-core variable inductor based on illumination adjustment according to claim 3, characterized in that, The controller switches the current value of the control winding according to the light intensity level to control whether the outer magnetic core segment is saturated.

7. The method for controlling a multi-core variable inductor based on illumination adjustment according to claim 1, characterized in that, The equivalent inductance value of the multi-core variable inductor has discrete variation characteristics, corresponding to different saturation combination states of the peripheral core segments.

8. The method for controlling a multi-core variable inductor based on illumination adjustment according to claim 1, characterized in that, The boost-type DC-DC power converter system dynamically adjusts the boost ratio by regulating the equivalent inductance value of the multi-core variable inductor to adapt to the working requirements under different light intensity conditions.

9. The method for controlling a multi-core variable inductor based on illumination adjustment according to claim 1, characterized in that, The controller periodically samples and averages the digital signal, and triggers a conduction mode switching control process when it detects that the light intensity level has crossed a critical threshold.

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