CN111542152A - Ultraviolet light source system with automatic feedback correction function of light intensity and its application - Google Patents

Abstract

An ultraviolet light source system with automatic light intensity feedback correction function and its application, the ultraviolet light source system comprises a power converter; a current collector; an ultraviolet light source; a photosensitive sensor; The set light intensity is output to the inner loop controller after calculation; and the inner loop controller controls the current value output by the power converter after processing the electrical signal fed back by the current collector and the signal output by the outer loop controller. The dual-loop control of the ultraviolet LED in the present invention can feedback the changes of the system current and light intensity from time to time, and the controller effectively adjusts the control end of the power converter, eliminates the influence of the ultraviolet LED's own light decay and power supply current changes, and ensures that the ultraviolet LED The output light power is constant to ensure the effectiveness of the UV light source.

Description

Ultraviolet light source system with automatic feedback correction function of light intensity and its application

technical field

The invention belongs to the technical field of semiconductors, in particular to an ultraviolet light source system with an automatic feedback correction function of light intensity and its application.

Background technique

Ultraviolet LEDs are gradually replacing the position of mercury lamps, and they are constantly entering people's production and life, and are used in printing, medical treatment, plant lighting, water treatment, disinfection and sterilization and other fields. However, the UV LED manufacturing process is not perfect, and the light intensity decays faster than blue LED or red LED during long-term work. The weakening of light intensity will inevitably affect the use effect of UV LED and reduce the performance in application.

In order to obtain a constant UV light intensity output, it is necessary to control the design of the UV LED.

SUMMARY OF THE INVENTION

In view of this, one of the main purposes of the present invention is to provide an ultraviolet light source system with automatic light intensity feedback correction function and its application, in order to at least partially solve at least one of the above technical problems.

In order to achieve the above purpose, as an aspect of the present invention, a UV light source system with automatic light intensity feedback correction function is provided, including:

The power converter converts the electric energy of the power supply into an adjustable current to supply the ultraviolet light source;

The current collector is used to detect the input current value and feed it back to the inner loop controller;

Ultraviolet light source, emit light intensity signal;

The photosensitive sensor converts the light intensity signal into an electrical signal and amplifies it and feeds it back to the outer loop controller;

The outer loop controller outputs the electrical signal fed back by the photosensitive sensor and the set light intensity to the inner loop controller after calculation; and

The inner loop controller controls the current value output by the power converter after processing the electrical signal fed back by the current collector and the signal output by the outer loop controller.

As another aspect of the present invention, an application of the above-mentioned ultraviolet light source system in the fields of printing, medical treatment, plant lighting, water treatment or disinfection and sterilization is also provided.

Based on the above technical solutions, it can be known that the ultraviolet light source system with the automatic light intensity feedback correction function of the present invention and its application have at least one of the following advantages over the prior art:

1. The present invention provides an ultraviolet light source with an automatic feedback correction function of light intensity. By controlling the input current of the ultraviolet LED to compensate the light decay part, the ultraviolet LED can work within the required light intensity range;

2. The dual-loop control of the ultraviolet LED in the present invention can feedback the changes of the system current and light intensity from time to time, and the controller can effectively adjust the control end of the power converter to eliminate the influence of the light decay of the ultraviolet LED itself and the change of the power supply current, so as to ensure The output light power of the UV LED is constant, ensuring the effectiveness of the UV light source.

Description of drawings

Fig. 1 is the structural principle block diagram of the ultraviolet light source with light intensity automatic feedback correction function in the embodiment of the present invention;

2 is a block diagram of a dual-loop control system in an embodiment of the present invention;

3 is a logical block diagram of automatic feedback control light intensity in an embodiment of the present invention;

FIG. 4 is a driving waveform diagram of an inner loop controller in an embodiment of the present invention.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

The invention discloses an ultraviolet light source system with an automatic feedback correction function of light intensity, comprising:

The power converter converts the electric energy of the power supply into an adjustable current to supply the ultraviolet light source;

The current collector is used to detect the input current value and feed it back to the inner loop controller;

Ultraviolet light source, emit light intensity signal;

The photosensitive sensor converts the light intensity signal into an electrical signal and amplifies it and feeds it back to the outer loop controller;

The outer loop controller outputs the electrical signal fed back by the photosensitive sensor and the set light intensity to the inner loop controller after calculation; and

The inner loop controller controls the current value output by the power converter after processing the electrical signal fed back by the current collector and the signal output by the outer loop controller.

In some embodiments of the present invention, the wavelength of the ultraviolet light source is less than 320 nm.

In some embodiments of the present invention, the ultraviolet light source includes at least one of an ultraviolet LED, a mercury lamp, a xenon lamp, or an ultraviolet fluorescent lamp.

In some embodiments of the present invention, the ultraviolet LED includes a single ultraviolet LED or a module composed of a plurality of ultraviolet LEDs.

In some embodiments of the present invention, the relative positions of the ultraviolet light source and the photosensitive sensor are fixed.

In some embodiments of the present invention, the ultraviolet light source system further includes an overcurrent and overvoltage protector for protecting the ultraviolet light source.

In some embodiments of the present invention, an upper limit of light intensity is set at the input end of the outer loop controller, and exceeding the set upper limit of light intensity is an invalid input.

In some embodiments of the present invention, the current collector includes a sampling resistor or a Hall sensor.

In some embodiments of the present invention, the control modes of the outer loop controller and the inner loop controller support analog control, digital control or mixed analog-digital control;

In some embodiments of the present invention, the control algorithms of the outer loop controller and the inner loop controller support PID control, fuzzy control or machine learning.

The invention also discloses the application of the above-mentioned ultraviolet light source system in the fields of printing, medical treatment, plant lighting, water treatment or disinfection and sterilization.

In an exemplary embodiment, an ultraviolet light source system with automatic light intensity feedback correction function of the present invention includes: a power converter 1 , a current collector 2 , an ultraviolet LED 3 , a photosensitive sensor 4 , and an outer loop controller 5 , Inner loop controller 6, overcurrent and overvoltage protector 7. The power converter 1 is connected to a power source, and is used for converting a current that meets the needs. The photosensitive sensor 4 receives the light intensity signal emitted by the ultraviolet LED 3 and converts the electrical signal, and feeds back the electrical signal amplified by a certain proportion to the outer loop controller 5. The amplified light intensity collects the electrical signal and the set light intensity is controlled in the outer loop. After the operation in the converter 5, the output signal is sent to the inner loop controller 6; the inner loop controller 6 processes the current acquisition signal and the transmission signal of the outer loop controller 5, and outputs the control signal to adjust the output current value of the power converter.

Among them, the control topology structure of the outer loop controller 5 and the inner loop controller 6 supports not only single-loop control, but also inner-loop and outer-loop dual-loop control, multi-loop control and its derivative topology control; the control mode supports analog control, Digital control, analog-digital hybrid control; control algorithm supports PID control, fuzzy control, machine learning and other control algorithms.

The inner loop controller 6 outputs a high-level signal to turn on the power converter 1, and adjusts the current in the ultraviolet LED 3 by controlling the high-level duty cycle.

Among them, setting the light intensity at the input end of the outer loop controller 5 and exceeding the upper limit set by the inner loop controller 5 are invalid inputs.

Among them, the overcurrent and overvoltage protector 7 protects the ultraviolet LED 3 from being damaged by high voltage and high current breakdown.

Among them, the current collector 2 is used to detect the input current value and feed it back to the inner loop controller 6 .

The photosensitive sensor 4 is used for receiving the light intensity signal sent by the ultraviolet LED 3 and feeding it back to the outer loop controller 5 .

Among them, the wavelength of the ultraviolet LED 3 is less than 320 nm, and it may be a module composed of a single ultraviolet LED or a plurality of ultraviolet LEDs.

Among them, the relative positions of the ultraviolet LED 3 and the photosensitive sensor 4 in the system are fixed.

The technical solutions of the present invention will be further described below through specific embodiments and accompanying drawings. It should be noted that the following specific embodiments are only for illustration, and the protection scope of the present invention is not limited thereto.

As shown in FIG. 1 , this embodiment discloses an ultraviolet light source system with automatic light intensity feedback correction function, which mainly includes: a power converter 1, a current collector 2, an ultraviolet LED 3, a photosensitive sensor 4, and an outer loop controller 5. Inner loop controller 6, overcurrent and overvoltage protector 7.

The power conversion 1 in this embodiment is connected to a power supply, and is used to convert the current into a required current, and convert the electric energy of the power supply into an adjustable current for the ultraviolet LED. The current collector 2 in this embodiment can choose to use a sampling resistor, a Hall sensor or other current collection elements. The current collector 2 is used to detect the change of the output current and transmit the collected current signal to the inner loop controller 6, The photosensitive sensor is used to receive the light intensity signal sent by the ultraviolet LED 3 , and the light intensity signal is converted into a weak electric signal, and after being amplified, it is transmitted to the outer loop controller 5 as a negative feedback electric signal of the outer loop circuit.

As shown in FIG. 2 , the controller in this embodiment is divided into an inner loop controller 6 and an outer loop controller 5 . The photosensitive sensor 4 receives the light intensity emitted by the ultraviolet LED and converts it into an electrical signal, which is fed back to the outer loop controller 5 after a certain amplification. to the inner loop controller 6.

The inner loop controller 6 compares the electrical signal fed back by the current collector 2 with the electrical signal output by the outer loop controller 5, and the compared electrical signal is processed inside the inner loop controller to control the output current of the power converter.

Internal and external faults in the system may cause high voltage or high current, resulting in breakdown of the UV LED3. The overcurrent and overvoltage protector 7 in this embodiment can detect high voltage or high current, turn off the output of the power converter, and protect the ultraviolet LED 3 . The UV LED3 is a module composed of a single LED or multiple UV LEDs with a wavelength of less than 400 nm; since the light intensity signal collected by the photosensitive sensor 4 is related to the distance of the UV LED3, the relative position of the UV LED3 and the photosensitive sensor 4 in the system is fixed. .

Taking the buck synchronous rectification circuit as an example below, the control process of the present invention will be described with reference to FIG. 3 . The examples are only used to explain the present invention, not to limit the scope of the present invention.

Set the UV LED light intensity signal received by the photosensitive sensor to output P _f after passing through the analog front end, and the given light intensity signal is P _g , then the difference between the light intensity and the feedback light intensity ΔP,

ΔP= _Pg - _Pf

Taking the PID control algorithm as an example, the output electrical signal calculated by the outer loop controller is calculated as:

Among them, K _P , K _I and K _D are the proportional, integral and differential coefficients set in the outer loop controller.

The output signal _Ig of the outer loop controller is used as the input signal of the inner loop controller.

The current collector collects I _f and feeds it back to the inner loop controller, and makes a difference with the output signal Ig of the outer loop controller to obtain ΔI,

_ΔI = _Ig -If

The inner loop controller internally calculates the duty cycle D of the output control terminal

Among them, K' _P , K' _I and K' _D are the proportional, integral and differential coefficients set in the inner loop controller.

D is the output duty cycle of the inner loop controller, see Figure 4.

The power converter has two signal input terminals: the control signal terminal HO and the synchronous rectification signal terminal LO. When D=0, HO outputs a low level, the upper switch tube of the power transmitter is turned off, and the circuit is in a stagnant state;

When D≥1, the upper switch tube of the power transmitter is in a normally open state, and the current flowing through the UV LED is the ratio of the internal resistance of the LED load of the supply voltage, which is the maximum current of the system;

When 0<D<I, the upper switch tube of the power converter is in the on time t _on , and the current of the UV LED is provided by the power supply after passing through the upper switch tube and the inductor; when the upper switch tube of the power converter is turned off at the time t _{In off} , the current of the UV LED is provided by the inductor and flows back through the lower switch tube; the constant current supply of the UV LED is realized by using the characteristics of the inductor itself, and then the constant power output of the UV LED is realized.

It can be seen that the automatic feedback ultraviolet light source system provided by the present invention can timely and effectively change the power supply current by feeding back the change of the light intensity, so as to ensure the stability of the ultraviolet light intensity.

The specific embodiments described above further describe the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above-mentioned specific embodiments are only specific embodiments of the present invention, and are not intended to limit the present invention. Within the spirit and principle of the present invention, any modifications, equivalent replacements, improvements, etc. made should be included within the protection scope of the present invention.

Claims (10)

1. An ultraviolet light source system with an automatic light intensity feedback correction function, comprising:

the power converter converts the electric energy of the power supply into adjustable current to supply to the ultraviolet light source;

the current collector is used for detecting an input current value and feeding back the input current value to the inner loop controller;

an ultraviolet light source for emitting a light intensity signal;

the photosensitive sensor converts the light intensity signal into an electric signal, amplifies the electric signal and feeds the electric signal back to the outer ring controller;

the outer ring controller outputs the electric signal fed back by the photosensitive sensor and the set light intensity to the inner ring controller after operation; and

and the inner-loop controller is used for controlling the current value output by the power converter after processing the electric signal fed back by the current collector and the signal output by the outer-loop controller.

2. The UV light source system of claim 1,

the wavelength of the ultraviolet light source is less than 320 nm.

3. The UV light source system of claim 1,

the ultraviolet light source comprises at least one of an ultraviolet LED, a mercury lamp, a xenon lamp or an ultraviolet fluorescent lamp.

4. The UV light source system of claim 3,

the ultraviolet LED comprises a single ultraviolet LED or a module consisting of a plurality of ultraviolet LEDs.

5. The UV light source system of claim 1,

the relative position of the ultraviolet light source and the photosensitive sensor is fixed.

6. The UV light source system of claim 1,

the ultraviolet light source system also comprises an overcurrent and overvoltage protector for protecting the ultraviolet light source.

7. The UV light source system of claim 1,

and setting an upper limit of light intensity at the input end of the outer ring controller, wherein the light intensity exceeding the upper limit of the set light intensity belongs to invalid input.

8. The UV light source system of claim 1,

the current collector comprises a sampling resistor or a Hall sensor.

9. The UV light source system of claim 1,

the control mode of the outer ring controller and the inner ring controller supports analog control, digital control or analog-digital mixed control;

the control algorithms of the outer ring controller and the inner ring controller support PID control, fuzzy control or machine learning.

10. Use of the uv light source system according to any one of claims 1 to 9 in the fields of printing, medical treatment, plant lighting, water treatment or disinfection and sterilization.

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