CN114390749A

CN114390749A - LED driving system for plant illumination and plant illumination system

Info

Publication number: CN114390749A
Application number: CN202111519763.3A
Authority: CN
Inventors: 华桂潮; 葛良安
Original assignee: Siwei Ecological Technology Hangzhou Co ltd
Current assignee: Siwei Ecological Technology Hangzhou Co ltd
Priority date: 2021-12-13
Filing date: 2021-12-13
Publication date: 2022-04-22

Abstract

The invention relates to an LED driving system for plant illumination and a plant illumination system, wherein the LED driving system comprises: the LED lamp comprises a constant voltage source and at least one first LED circuit, wherein the first LED circuit is electrically connected to two ends of the constant voltage source and comprises a plurality of lamp bead units and a DC/DC power processing circuit, the DC/DC power processing circuit is sequentially connected with the plurality of lamp bead units in series through a positive input end and a negative input end of the DC/DC power processing circuit, a positive output end of the DC/DC power processing circuit is electrically connected to a positive electrode of one of the lamp bead units in the first LED circuit, a negative output end of the DC/DC power processing circuit is electrically connected to a negative end of the constant voltage source, each lamp bead unit is composed of at least one LED lamp bead, at least one second LED circuit is electrically connected to two ends of the constant voltage source, and the second LED circuit is electrically connected to two ends of the constant voltage source. Through setting up DC/DC power processing circuit, can supply first LED circuit again with another direct current voltage with the voltage conversion of some lamp pearl units, improved lighting system's lighting efficiency.

Description

LED driving system for plant illumination and plant illumination system

Technical Field

The invention relates to the technical field of plant illumination, in particular to an LED driving system for plant illumination and a plant illumination system.

Background

In a conventional multi-path lighting system, a constant voltage source supplies power to a plurality of paths of LED light sources, and therefore, a constant voltage source having an output voltage higher than the voltage of the LED lights of all the paths needs to be selected to ensure that each path of LED lights can emit light, and in order to make the light emitted by each path of LED lights consistent, a current limiting module needs to be connected in series with each path of LED lights to limit the current of the path not to exceed a preset value.

However, in an indoor lighting system of a plant factory or a supplementary lighting system of a plant, each path of LED lamps forms one LED lamp, and plant cultivation areas are different, that is, lighting areas of each corresponding LED lamp are different, so that a long power supply line is required between the same constant voltage source and the LED lamp supplied with power, and loss on the power supply line increases with increasing distance, which results in that the LED lamp located farthest from the constant voltage source obtains a voltage that is reduced accordingly. Therefore, when the technical scheme of supplying power to the multiple LED lamps by the constant voltage source is used for plant illumination, the voltage of the LED lamps is likely to be higher than the output voltage of the constant voltage source.

In order to ensure that an LED lamp with a higher voltage (e.g., a remote LED lamp) can emit light normally, a constant voltage source with a higher output voltage is generally used in designing an illumination scheme, but the following problems exist in the lighting scheme: in the LED lamp with lower voltage, the difference between the rated value of the voltage and the output voltage of the constant voltage source is larger, the redundant voltage is absorbed by the current limiting module, the current limiting module generates excessive power, and the power is dissipated by heat energy. For plant lighting systems, lighting efficiency is extremely important, and such lighting schemes do not achieve high efficiency and suffer from large power losses.

Therefore, it is required to provide an LED driving system that makes full use of the power supply and improves the lighting efficiency, and can achieve automatic adjustment of the current or voltage in the LED circuit to solve the above technical problems.

Disclosure of Invention

In order to solve the technical problem, the invention provides an LED driving system for plant illumination. The technical problem of high power loss caused by high heat energy dissipation generated when redundant voltage is borne by the current limiting module in a branch where the LED lamp with low voltage is located in the prior art is solved.

The technical effects of the invention are realized as follows:

an LED driving system for plant lighting, comprising:

a constant-voltage source for supplying a constant voltage,

the first LED circuit is electrically connected to two ends of the constant voltage source and comprises a plurality of lamp bead units and a DC/DC power processing circuit, the DC/DC power processing circuit is sequentially connected with the lamp bead units in series through a positive input end and a negative input end of the DC/DC power processing circuit, a positive output end of the DC/DC power processing circuit is electrically connected to a positive electrode of one of the lamp bead units in the first LED circuit, a negative output end of the DC/DC power processing circuit is electrically connected to a negative end of the constant voltage source, each lamp bead unit is composed of at least one LED lamp bead, and the DC/DC power processing circuit is used for detecting the current of the first LED circuit or the voltage of other lamp bead units except for a part of the lamp bead units in the first LED circuit so as to control the current or the voltage of a part of the lamp bead units to be equal to a preset value, the second LED circuit is electrically connected to two ends of the constant voltage source and comprises a plurality of lamp bead units connected in series. By arranging the DC/DC power handling circuit such that, when the voltage required for normal illumination of the first LED circuit is lower than the constant voltage source output voltage, the DC/DC power processing circuit is used for processing the power, the voltage of other lamp bead units except the part of the lamp bead units electrically connected with the two ends of the voltage control circuit is converted into another direct current voltage to be transmitted to the first LED circuit, the automatic adjustment of the current or the voltage in the first LED circuit is realized, thereby making the power supply fully utilized for illumination, and simultaneously adjusting the current or voltage of the first LED circuit to be equal to the corresponding preset value, the LED lamp beads in the first LED circuit can normally emit light, and the technical problem that in the prior art, too high heat energy dissipation is generated when redundant voltage is borne through the current limiting module in an LED branch circuit with low voltage required by illumination, so that large power loss is caused is solved.

Further, the DC/DC power processing circuit includes a DC/DC main circuit and a current control circuit, the current control circuit includes a proportional-integral circuit, the current control circuit is configured to control the current value of the first LED circuit to be equal to a current preset value by inputting the detected current value of the first LED circuit into the proportional-integral circuit to make the output voltage amplitude of the proportional-integral circuit adjust the input power of the DC/DC main circuit, and the output voltage amplitude of the proportional-integral circuit and the detected difference between the current value of the first LED circuit and the current preset value are in a proportional-integral relationship. Through setting up DC/DC main circuit and current control circuit for can detect the electric current of first LED circuit and input the detected value of this electric current into proportional-integral circuit, the input power of rethread proportional-integral circuit control DC/DC main circuit is in order to adjust the electric current of first LED circuit, thereby guarantees that the electric current of first LED circuit equals the current default, makes LED lamp pearl in the first LED circuit normally luminous.

Further, the DC/DC power processing circuit includes a DC/DC main circuit and a voltage control circuit, both ends of the voltage control circuit are electrically connected to both ends of any part of the lamp bead units in the first LED circuit, the voltage control circuit includes a proportional-integral circuit, the voltage control circuit is configured to input the detected voltage values of other lamp bead units except for the part of the lamp bead units electrically connected to both ends of the voltage control circuit in the first LED circuit into the proportional-integral circuit, so that the output voltage amplitude of the proportional-integral circuit adjusts the input power of the DC/DC main circuit to control the voltage at both ends of the part of the lamp bead units in the first LED circuit to be equal to a preset voltage value, and the output voltage amplitude of the proportional-integral circuit and the voltage value of other lamp bead units except for the part of the lamp bead units electrically connected to both ends of the voltage control circuit in the first LED circuit are equal to the preset voltage value The difference is proportional integral. Through setting up DC/DC main circuit and voltage control circuit for can detect the voltage of other lamp pearl units outside the some lamp pearl units of the well and voltage control circuit both ends electricity of first LED circuit and be connected and input this voltage's detected value to proportional-integral circuit, the input power of rethread proportional-integral circuit control DC/DC main circuit is in order to adjust the voltage at some lamp pearl unit both ends, make the voltage at some lamp pearl unit both ends equal the voltage default, thereby guarantee that the electric current of first LED circuit equals the electric current default of LED lamp pearl, make LED lamp pearl in the first LED circuit can normally give off light.

Further, the DC/DC main circuit is a non-isolated circuit.

Further, the DC/DC main circuit is a Boost circuit, the Boost circuit comprises a first controllable switch tube, a first diode and a first inductor, one end of the first inductor is electrically connected with the positive input end of the Boost circuit, the other end of the first inductor is electrically connected with the anode of the first diode, the negative electrode of the first diode is electrically connected with the positive output end of the Boost circuit, one end of the first controllable switch tube is electrically connected with the positive electrode of the first diode, the negative input end and the negative output end of the Boost circuit are both electrically connected with the other end of the first controllable switch tube, the current control circuit is used for detecting the current of the first LED circuit to control the duty ratio of the first controllable switch tube or the voltage control circuit is used for detecting the voltage values of other lamp bead units except a part of lamp bead units electrically connected with two ends of the voltage control circuit in the first LED circuit to control the duty ratio of the first controllable switch tube.

Further, the DC/DC main circuit is an isolation circuit.

Further, the DC/DC main circuit is a Flyback circuit, the Flyback circuit includes a second controllable switch tube, a second diode and a transformer, the positive input end of the transformer is electrically connected with the positive input end of the Flyback circuit, the negative input end of the transformer is electrically connected with the negative input end of the Flyback circuit through the second controllable switch tube, the positive output end of the transformer is electrically connected with the positive end of the second diode, the negative end of the second diode is electrically connected with the positive output end of the Flyback circuit, the negative output end of the transformer is electrically connected with the negative output end of the Flyback circuit, the current control circuit is used for detecting the current of the first LED circuit to control the duty ratio of the first controllable switch tube or the voltage control circuit is used for detecting the voltage values of other units of the first LED circuit except for the portion of the lamp bead units electrically connected with the two ends of the voltage control circuit to control the lamp bead units of the first controllable switch tube Duty cycle.

Further, all components except the magnetic device in the DC/DC power processing circuit are integrated into an integrated circuit.

Further, the second LED circuit further comprises a current limiting module, and the current limiting module is sequentially connected with the plurality of lamp bead units in the second LED circuit in series.

In addition, a plant lighting system is also provided, and the LED driving system for plant lighting comprises the LED driving system for plant lighting.

As described above, the present invention has the following advantageous effects:

1) by arranging the DC/DC power handling circuit such that, when the voltage required for normal illumination of the first LED circuit is lower than the constant voltage source output voltage, the DC/DC power processing circuit is used for processing the power, the voltage of other lamp bead units except the part of the lamp bead units electrically connected with the two ends of the voltage control circuit is converted into another direct current voltage to be transmitted to the first LED circuit, the automatic adjustment of the current or the voltage in the first LED circuit is realized, thereby making the power supply fully utilized for illumination, and simultaneously adjusting the current or voltage of the first LED circuit to be equal to the corresponding preset value, the LED lamp beads in the first LED circuit can normally emit light, and the technical problem that in the prior art, too high heat energy dissipation is generated when redundant voltage is borne through the current limiting module in an LED branch circuit with low voltage required by illumination, so that large power loss is caused is solved.

2) Through setting up DC/DC main circuit and current control circuit for can detect the electric current of first LED circuit and input the detected value of this electric current into proportional-integral circuit, the input power of rethread proportional-integral circuit control DC/DC main circuit is in order to adjust the electric current of first LED circuit, thereby guarantees that the electric current of first LED circuit equals the current default, makes LED lamp pearl in the first LED circuit normally luminous.

3) Through setting up DC/DC main circuit and voltage control circuit for can detect the voltage of other lamp pearl units outside the some lamp pearl units of the well and voltage control circuit both ends electricity of first LED circuit and be connected and input this voltage's detected value to proportional-integral circuit, the input power of rethread proportional-integral circuit control DC/DC main circuit is in order to adjust the voltage at some lamp pearl unit both ends, make the voltage at some lamp pearl unit both ends equal the voltage default, thereby guarantee that the electric current of first LED circuit equals the electric current default of LED lamp pearl, make LED lamp pearl in the first LED circuit can normally give off light.

Drawings

In order to more clearly illustrate the technical solution of the present invention, the drawings used in the description of the embodiment or the prior art will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the invention, and that for a person skilled in the art it is also possible to derive other drawings from these drawings without inventive effort.

Fig. 1 is a schematic block diagram of an LED driving system for plant illumination according to an embodiment of the present disclosure;

fig. 2 is a schematic block diagram of another LED driving system for plant illumination provided in the embodiments of the present disclosure;

FIG. 3 is a schematic block diagram of a DC/DC main circuit and a current control circuit provided in an embodiment of the present disclosure;

FIG. 4 is a schematic block diagram of a DC/DC main circuit and a voltage control circuit provided in an embodiment of the present disclosure;

fig. 5 is a schematic block diagram of a DC/DC main circuit provided in an embodiment of the present disclosure when the DC/DC main circuit is a Boost circuit;

fig. 6 is a schematic block diagram of the DC/DC main circuit provided in the embodiment of the present disclosure when the DC/DC main circuit is a Flyback circuit;

FIG. 7 is a schematic block diagram of a current control circuit or a voltage control circuit provided by an embodiment of the present disclosure;

fig. 8 is a schematic block diagram of a current limiting module disposed in a second LED circuit in an LED driving system for plant illumination provided in an embodiment of the present disclosure.

Wherein the reference numerals in the figures correspond to:

the LED lamp comprises a constant voltage source 1, a first LED circuit 2, an LED lamp bead 21, a DC/DC power processing circuit 22, a DC/DC main circuit 221, a current control circuit 222, a voltage control circuit 223, a second LED circuit 3, a current limiting module 31, a Boost circuit 4, a first controllable switch tube 41, a first diode 42, a first inductor 43, a Flyback circuit 5, a second controllable switch tube 51, a second diode 52 and a transformer 53.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

Example 1:

as shown in fig. 1-8, embodiments of the present specification provide an LED driving system for plant illumination, including:

the constant-voltage source 1 is provided with a constant-voltage source,

the LED lamp comprises at least one first LED circuit 2, the first LED circuit 2 is electrically connected with two ends of a constant voltage source 1, the first LED circuit 2 comprises a plurality of lamp bead units and a DC/DC power processing circuit 22, the DC/DC power processing circuit 22 is sequentially connected with the plurality of lamp bead units in series through a positive input end and a negative input end of the DC/DC power processing circuit 22, a positive output end of the DC/DC power processing circuit 22 is electrically connected with a positive electrode of one of the lamp bead units in the first LED circuit 2, a negative output end of the DC/DC power processing circuit 22 is electrically connected with a negative end of the constant voltage source 1, each lamp bead unit is composed of at least one LED lamp bead 21, the DC/DC power processing circuit 23 is used for detecting the current of the first LED circuit 2 or the voltage of other lamp bead units except for a part of the lamp bead units in the first LED circuit 2 so as to control the current or the voltage of the part of the lamp bead units to be equal to a preset value, and at least one second LED circuit 3, the second LED circuit 3 is electrically connected to both ends of the constant voltage source 1, and the second LED circuit 3 includes a plurality of lamp bead units connected in series.

Specifically, the lamp bead unit may be one LED lamp bead 21, or may be formed by connecting more than one LED lamp beads 21 in series or in parallel or in series-parallel, and the plurality of lamp bead units may be the same or different. In the embodiment, the lamp bead unit is used as one LED lamp bead 21 for explanation.

It should be noted that, in the existing plant lighting system, in order to ensure that the LED lamp with higher voltage (for example, a remote LED lamp) emits light normally, a constant voltage source with higher output voltage is generally selected when designing the lighting scheme, but the following problems may occur in the scheme: in the LED lamp with a lower voltage, the difference between the rated voltage value and the output voltage of the constant voltage source is larger, the excess voltage is absorbed by the current limiting module, and the current limiting module generates excessive power and dissipates the power by means of heat energy. For plant lighting systems, lighting efficiency is extremely important, and such lighting schemes cannot achieve high lighting efficiency, with large power losses.

Therefore, by arranging the DC/DC power processing circuit 22, when the voltage required by the normal illumination of the first LED circuit 2 is lower than the output voltage of the constant voltage source 1, the power is processed by the DC/DC power processing circuit 22, the processed power is transmitted to part of the LED lamp beads 21 or all of the LED lamp beads 21 in the first LED circuit 2, and the automatic adjustment of the current or the voltage in the first LED circuit 2 is realized, so that the power supply is fully utilized for the illumination, and meanwhile, the current or the voltage of the first LED circuit 2 is adjusted to be equal to the preset value, so that the LED lamp beads 21 in the first LED circuit 2 can normally emit light, thereby solving the technical problem that in the prior art, when the redundant voltage is borne by the current limiting module in the LED branch with lower illumination voltage, the excessive heat energy dissipation is generated, and the large power loss is caused.

Specifically, taking an example that the first LED circuit 2 is formed by directly connecting a plurality of LED lamp beads 21 and positive and negative input terminals of the DC/DC power processing circuit 22 in series, the DC/DC power processing circuit 22 includes the following three connection modes:

in a first embodiment, the negative input of the DC/DC power processing circuit 22 serves as the negative terminal of the first LED circuit 2, as shown in fig. 1;

in the first embodiment, the positive input of the DC/DC power processing circuit 22 serves as the positive terminal of the first LED circuit 2;

in another embodiment, the positive input of the DC/DC power processing circuit 22 is electrically connected to the negative terminal of the lamp bead unit in the first LED circuit 2, and the negative input of the DC/DC power processing circuit 22 is electrically connected to the first LED circuit 2; the positive terminal of the other lamp bead unit is electrically connected as shown in fig. 2.

Preferably, the lamp bead unit of the first LED circuit 2 and the lamp bead unit of the second LED circuit 3 are disposed in different light fixtures.

In the LED driving system of the present application, one constant voltage source 1 may be electrically connected to a plurality of first LED circuits 2, all of the first LED circuits 2 may be provided with one DC/DC power processing circuit 22, or some of the first LED circuits 2 may be provided with the DC/DC power processing circuit 22.

The DC/DC power processing circuit 22 in this application has two embodiments:

in one embodiment, as shown in fig. 3, the DC/DC power processing circuit 22 comprises a DC/DC main circuit 221 and a current control circuit 222, the current control circuit 222 comprises a proportional-integral circuit, the current control circuit 222 is configured to control the current value of the first LED circuit 2 to be equal to a current preset value by inputting the detected current value of the first LED circuit 2 into the proportional-integral circuit to make the output voltage amplitude of the proportional-integral circuit adjust the input power of the DC/DC main circuit 221 so as to control the current value of the first LED circuit 2 to be equal to the current preset value, and the output voltage amplitude of the proportional-integral circuit and the difference between the detected current value of the first LED circuit 2 and the current preset value are in proportional-integral relation.

Wherein, the current control circuit 222 is configured to detect a current of the first LED circuit 2 connected to the input end of the DC/DC main circuit 221, a detected value of the current of the first LED circuit 2 and a preset current value are input into the proportional-integral circuit, an output voltage amplitude of the proportional-integral circuit and a difference between the detected value and the preset value of the current of the first LED circuit 2 are in a proportional-integral relationship, so as to control the DC/DC main circuit 221 through the output voltage of the proportional-integral circuit, so that a processing power (input power) of the DC/DC main circuit 221 changes along with the change of the output voltage amplitude of the proportional-integral circuit, thereby adjusting the processing power (input power) of the DC/DC main circuit 221 to adjust the current of the first LED circuit 2 to be equal to the preset current value, the preset current value is a rated current calculated according to a connection manner of the plurality of bead units 24 in the first LED circuit 2, namely, the current of the first LED circuit 2 when the LED lamp bead 21 in the first LED circuit 2 emits light normally.

For example, when the output voltage of the constant voltage source 1 is higher and the voltage required for the normal light emission of the LED lamp bead 21 in one of the first LED circuits 2 is relatively lower, the current of the first LED circuit 2 is higher than the preset value in the current control circuit 222, at this time, the proportional-integral circuit in the current control circuit 222 outputs a control signal to control the duty ratio or the switching frequency of the controllable switching tube in the DC/DC main circuit 221, so that the input power of the DC/DC main circuit 221 is gradually reduced, thereby reducing the current of the first LED circuit 2, and this adjustment process is circulated until the detection value of the current of the first LED circuit 2 is equal to the preset value.

In another embodiment, as shown in fig. 4, the DC/DC power processing circuit 22 includes a DC/DC main circuit 221 and a voltage control circuit 223, two ends of the voltage control circuit 223 are electrically connected to two ends of any part of the lamp bead units in the first LED circuit 2, the voltage control circuit 223 includes a proportional integral circuit, the voltage control circuit 223 is configured to input the detected voltage values of other lamp bead units except the part of the lamp bead units electrically connected to two ends of the voltage control circuit 223 in the first LED circuit 2 into the proportional integral circuit so that the output voltage amplitude of the proportional integral circuit adjusts the input power of the DC/DC main circuit 221 to control the voltage at two ends of the part of the lamp bead units in the first LED circuit 2 to be equal to a preset voltage value, and the output voltage amplitude of the proportional integral circuit and the difference between the voltage values at two ends of the part of the lamp bead units in the first LED circuit 2 and the preset voltage value are in a proportional integral relationship.

Any part of the lamp bead units in the first LED circuit 2 may be all the lamp bead units in the first LED circuit 2, or may be lamp bead units sequentially connected in series in the first LED circuit 2, or may be any one of the lamp bead units in the first LED circuit 2.

It should be noted that the voltage value detected by the voltage control circuit 223 is the voltage value of all other lamp bead units except the part of the lamp bead units electrically connected to the two ends of the voltage control circuit 223 in the first LED circuit 2.

Specifically, when the DC/DC power processing circuit 23 is configured to detect voltages of other lamp bead units outside the partial lamp bead units in the first LED circuit 2 to control the voltages of the partial lamp bead units to be equal to the preset value, where the other lamp bead units outside the partial lamp bead units in the first LED circuit 2 refer to all other lamp bead units outside the partial lamp bead units electrically connected to two ends of the voltage control circuit 223 in the first LED circuit 2.

Specifically, the voltage control circuit 223 is configured to detect a voltage value of a portion of the first LED circuit 2 other than the portion of the lamp bead units electrically connected to the two ends of the voltage control circuit 223, and input a voltage detection value and a preset voltage value of the portion of the first LED circuit other than the portion of the lamp bead units electrically connected to the two ends of the voltage control circuit 223 into the proportional integral circuit, where an output voltage amplitude of the proportional integral circuit is proportional-integral with a difference between the voltage detection value and the preset voltage value, so as to control the DC/DC main circuit 221 through the output voltage of the proportional integral circuit, so that a processing power (input power) of the DC/DC main circuit 221 changes along with a change in the output voltage amplitude of the proportional integral circuit, thereby adjusting the processing power (input power) of the DC/DC main circuit 221 to adjust the voltages at the two ends of the portion of the lamp bead units to be equal to the preset voltage value, the voltage preset value is a rated voltage calculated according to the connection mode of the two ends of a part of the lamp bead units, namely, the voltage of the two ends of the part of the lamp bead units when the LED lamp beads 21 in the first LED circuit 2 normally emit light.

It should be noted that, the power of the first LED circuit 2 is redistributed by the DC/DC main circuit 221, so that the current of the other lamp bead units except for the part of the lamp bead units electrically connected to the two ends of the voltage control circuit 223 is equal to the preset current value or the voltage of the other lamp bead units except for the part of the lamp bead units electrically connected to the two ends of the voltage control circuit 223 is equal to the preset voltage value, thereby ensuring that the other lamp bead units except for the part of the lamp bead units electrically connected to the two ends of the voltage control circuit 223 can normally emit light.

In the present application, when the DC/DC main circuit 221 is a non-isolated circuit, the control method is described as the current control circuit 222: the DC/DC main circuit 221 may be implemented by a Boost circuit, as shown in fig. 5, the DC/DC main circuit 221 is a Boost circuit 4, the Boost circuit 4 includes a first controllable switch tube 41, a first diode 42 and a first inductor 43, one end of the first inductor 43 is electrically connected to a positive input terminal of the Boost circuit 4, the other end of the first inductor 43 is electrically connected to a positive electrode of the first diode 42, a negative electrode of the first diode 42 is electrically connected to a positive output terminal of the Boost circuit 4, one end of the first controllable switch tube 41 is electrically connected to a positive electrode of the first diode 42, a negative input terminal and a negative output terminal of the Boost circuit 4 are electrically connected to the other end of the first controllable switch tube 41, a current control circuit 222 is configured to detect a current of the first LED circuit 2 to control a duty ratio of the first controllable switch tube 41, or a voltage control circuit 223 is configured to detect a voltage value of other than a bead unit electrically connected to two ends of the voltage control circuit 223 in the first LED circuit 2 to control a bead unit of the first controllable switch tube 41 Duty cycle.

In the first LED circuit 2 with a lower rated voltage, the current detection value in the current control circuit 222 will be higher than the current preset value, and at this time, the proportional-integral circuit outputs a control signal to control the duty ratio D to decrease until the current detection value is equal to the current preset value. The rated voltage of the first LED circuit 2 is the voltage at the two ends of the first LED circuit 2 when the LED lamp bead 21 in the first LED circuit 2 emits light normally.

In the present application, when the DC/DC main circuit 221 is an isolation circuit, the current control circuit 222 is used as a control method in the present embodiment, and the embodiment is as follows:

as shown in fig. 6, the DC/DC main circuit 221 is a Flyback circuit 5, the Flyback circuit 5 includes a second controllable switch 51, a second diode 52 and a transformer 53, a positive input terminal of the transformer 53 is electrically connected to a positive input terminal of the Flyback circuit 5, a negative input terminal of the transformer 53 is electrically connected to a negative input terminal of the Flyback circuit 5 through the second controllable switch 51, a positive output terminal of the transformer 53 is electrically connected to a positive terminal of the second diode 52, a negative terminal of the second diode 52 is electrically connected to a positive output terminal of the Flyback circuit 5, a negative output terminal of the transformer 53 is electrically connected to a negative output terminal of the Flyback circuit 5, the current control circuit 222 is configured to detect a current of the first LED circuit 2 to control a duty ratio of the first controllable switch tube 41, or the voltage control circuit 223 is configured to detect a voltage value of a portion of the first LED circuit 2 other than a portion of the lamp bead units electrically connected to two ends of the voltage control circuit 223 to control the duty ratio of the first controllable switch tube 41.

The positive output end of the Flyback circuit 5 is electrically connected to any node B in the first LED circuit 2, the negative output end is electrically connected to a node a in the first LED circuit 2, the voltage of the node a is lower than that of the node B, and the node a and the node B are connection nodes between the LED lamp beads 21 or the lamp bead units in the first LED circuit 2.

Specifically, the current control circuit 222 or the voltage control circuit 222 can be implemented by fig. 7, when the current control circuit 222 is used as a control circuit, the negative phase input terminal of the operational amplifier in the current control circuit 222 is connected to Ic, i.e. the detection signal of the current in the first LED circuit 2; when the voltage control circuit 223 is used as a control circuit, the negative phase input end of the operational amplifier is connected with Vc, that is, the voltage detection signals of the other lamp bead units except the part of the lamp bead units electrically connected with the two ends of the voltage control circuit 223 in the first LED circuit 2. The non-inverting input end of the operational amplifier is connected with a reference signal, and the reference signal is used for setting a current preset value or a voltage preset value. The operational amplifier output end is connected with a driving unit, and outputs a PWM signal according to the voltage of the operational amplifier output end, the duty ratio or frequency of the PWM signal changes with the change of the operational amplifier input voltage, and the PWM signal is output to the control end of the controllable switch tube in the DC/DC main circuit 221 to control the conduction and disconnection of the controllable switch tube, thereby controlling the processing power of the DC/DC main circuit 221.

The following description will be made by taking an example in which the current control circuit 222 controls the duty ratio change of the PWM signal: when the output voltage of the constant voltage source 1 is high and the rated voltage of the first LED circuit 2 is relatively low, the current in the first LED circuit 2 is higher than the rated current, that is, the detection value Ic is higher than the preset value Vr, so that the output voltage of the operational amplifier is reduced, the duty ratio of the PWM signal output by the driving unit is reduced, and thus the duty ratio of the controllable switching tube in the DC/DC main circuit 221 is reduced, the processing power (input power) of the DC/DC main circuit 221 is reduced, the current of the first LED circuit 2 is also reduced, that is, Ic is reduced, and the adjustment process is cycled until the detection value Ic is equal to the preset value Vr.

Preferably, the components in the DC/DC power processing circuit 22 are integrated into one integrated circuit. Here, the components refer to all elements except the magnetic device.

Preferably, as shown in fig. 8, the second LED circuit 3 further includes a current limiting module 31, and the current limiting module 31 and the plurality of lamp bead units in the second LED circuit 3 are sequentially connected in series.

Example 2:

the embodiment of the specification provides a plant lighting system, which comprises a plurality of LED driving systems for plant lighting in the embodiment 1. A plant lighting system includes a plurality of LED driving systems in embodiment 1, that is, a plurality of constant voltage sources 1, and each constant voltage source 1 is electrically connected to a plurality of first LED circuits 2 configured with DC/DC power processing circuits 22, so as to realize accurate control of the LED driving systems corresponding to different plant lighting areas.

Although the present invention has been described by way of preferred embodiments, the present invention is not limited to the embodiments described herein, and various changes and modifications may be made without departing from the scope of the present invention.

In this document, the terms front, back, upper and lower are used to define the components in the drawings and the positions of the components relative to each other, and are used for clarity and convenience of the technical solution. It is to be understood that the use of the directional terms should not be taken to limit the scope of the claims.

The embodiments and features of the embodiments described herein above can be combined with each other without conflict.

While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

1. An LED driving system for plant lighting, comprising:

a constant voltage source (1),

at least one first LED circuit (2), the first LED circuit (2) is electrically connected to two ends of the constant voltage source (1), the first LED circuit (2) comprises a plurality of lamp bead units and a DC/DC power processing circuit (22), the DC/DC power processing circuit (22) is sequentially connected in series through a positive input end, a negative input end and the plurality of lamp bead units, a positive output end of the DC/DC power processing circuit (22) is electrically connected to a positive electrode of one of the lamp bead units in the first LED circuit (2), a negative output end of the DC/DC power processing circuit (22) is electrically connected to a negative end of the constant voltage source (1), the lamp bead unit is composed of at least one LED lamp bead (21), and the DC/DC power processing circuit (23) is used for detecting the current of the first LED circuit (2) or the voltage of other lamp bead units except for a part unit in the first LED circuit (2) to control the current or the voltage of the other lamp bead units except for the part unit in the first LED circuit (2) The voltage of part of the lamp bead units is equal to the preset value,

the LED lamp comprises at least one second LED circuit (3), wherein the second LED circuit (3) is electrically connected to two ends of the constant voltage source (1), and the second LED circuit (3) comprises a plurality of lamp bead units which are connected in series.

2. The LED driving system for plant lighting according to claim 1, characterized in that the DC/DC power processing circuit (22) comprises a DC/DC main circuit (221) and a current control circuit (222), the current control circuit (222) comprising a proportional-integral circuit, the current control circuit (222) being arranged to control the current value of the first LED circuit (2) to be equal to a current preset value by inputting the detected current value of the first LED circuit (2) into the proportional-integral circuit such that the output voltage amplitude of the proportional-integral circuit adjusts the input power of the DC/DC main circuit (221) to control the current value of the first LED circuit (2) to be equal to the current preset value, the output voltage amplitude of the proportional-integral circuit and the detected difference between the current value of the first LED circuit (2) and the current preset value being in a proportional-integral relation.

3. The LED driving system for plant illumination according to claim 1, wherein the DC/DC power processing circuit (22) comprises a DC/DC main circuit (221) and a voltage control circuit (223), two ends of the voltage control circuit (223) are electrically connected to two ends of any part of the lamp bead units in the first LED circuit (2), the voltage control circuit (223) comprises a proportional integral circuit, and the voltage control circuit (223) is configured to control the voltage across the part of the lamp bead units in the first LED circuit (2) to be equal to a preset voltage value by inputting the detected voltage value of the other lamp bead units except the part of the lamp bead units in the first LED circuit (2) which are electrically connected to two ends of the voltage control circuit (223) into the proportional integral circuit so that the output voltage amplitude of the proportional integral circuit adjusts the input power of the DC/DC main circuit (221) to control the voltage across the part of the lamp bead units in the first LED circuit (2) to be equal to the preset voltage value, the output voltage amplitude of the proportional-integral circuit and the difference between the voltage value of the other lamp bead units except the part of the lamp bead units electrically connected with the two ends of the voltage control circuit (223) in the first LED circuit (2) and the preset voltage value are in proportional-integral relation.

4. The LED driving system for plant lighting according to claim 2 or 3, characterized in that the DC/DC main circuit (221) is a non-isolated circuit.

5. The LED driving system for plant lighting according to claim 4, wherein the DC/DC main circuit (221) is a Boost circuit (4), the Boost circuit (4) comprises a first controllable switch tube (41), a first diode (42) and a first inductor (43), one end of the first inductor (43) is electrically connected with a positive input end of the Boost circuit (4), the other end of the first inductor (43) is electrically connected with a positive electrode of the first diode (42), a negative electrode of the first diode (42) is electrically connected with a positive output end of the Boost circuit (4), one end of the first controllable switch tube (41) is electrically connected with a positive electrode of the first diode (42), a negative input end and a negative output end of the Boost circuit (4) are both electrically connected with the other end of the first controllable switch tube (41), and the current control circuit (222) is used for detecting the current of the first LED circuit (2) to control the first controllable switch tube (41) And the duty ratio of the switch tube (41) or the voltage control circuit (223) is used for detecting the voltage values of other lamp bead units except the part of the lamp bead units electrically connected with the two ends of the voltage control circuit (223) in the first LED circuit (2) so as to control the duty ratio of the first controllable switch tube (41).

6. The LED driving system for plant lighting according to claim 2 or 3, characterized in that the DC/DC main circuit (221) is an isolation circuit.

7. The LED driving system for plant lighting according to claim 6, wherein the DC/DC main circuit (221) is a Flyback circuit (5), the Flyback circuit (5) comprises a second controllable switch tube (51), a second diode (52) and a transformer (53), a positive input terminal of the transformer (53) is electrically connected with a positive input terminal of the Flyback circuit (5), a negative input terminal of the transformer (53) is electrically connected with a negative input terminal of the Flyback circuit (5) through the second controllable switch tube (51), a positive output terminal of the transformer (53) is electrically connected with a positive terminal of the second diode (52), a negative terminal of the second diode (52) is electrically connected with a positive output terminal of the Flyback circuit (5), a negative output terminal of the transformer (53) is electrically connected with a negative output terminal of the Flyback circuit (5), the current control circuit (222) is used for detecting the current of the first LED circuit (2) to control the duty ratio of the first controllable switch tube (41) or the voltage control circuit (223) is used for detecting the voltage values of other lamp bead units except for a part of lamp bead units electrically connected with two ends of the voltage control circuit (223) in the first LED circuit (2) to control the duty ratio of the first controllable switch tube (41).

8. The LED driving system for plant lighting according to claim 1, wherein all components except the magnetic device in the DC/DC power processing circuit (22) are integrated into one integrated circuit.

9. The LED driving system for plant lighting according to claim 1, wherein the second LED circuit (3) further comprises a current limiting module (31), and the current limiting module (31) and the plurality of lamp bead units in the second LED circuit (3) are sequentially connected in series.

10. A plant lighting system comprising a plurality of LED driving systems for lighting a plant as claimed in any one of claims 1 to 9.