CN109688669A - A kind of High Power Factor no electrolytic capacitor LED drive power and its control method - Google Patents

Abstract

The present invention relates to a kind of High Power Factor no electrolytic capacitor LED drive power and its control methods, including rectification circuit, two-way crisscross parallel Boost circuit, auxiliary circuit and LED load etc.；The work of two-way crisscross parallel Boost circuit realizes power factor emendation function and current constant control in discontinuous conduct mode；Difference of the auxiliary circuit for symmetrical alternating current input instantaneous power and direct current output instantaneous power, to avoid that thin-film capacitor substitution electrolytic capacitor can be used, realize no electrolytic capacitor LED drive power using big capacity electrolyte capacitor；Low ripple output may be implemented by the coordinated control to crisscross parallel Boost circuit and auxiliary circuit and to the current constant control of LED load.

Description

A high power factor non-electrolytic capacitor LED driving power supply and its control method

technical field

The invention relates to the field of LED driving, in particular to a high power factor non-electrolytic capacitor LED driving power supply and a control method thereof.

Background technique

With its advantages of energy saving, environmental protection, high efficiency and long life, LED has become a new generation of green lighting source. With the increasing maturity of LED lighting technology, it will be widely used in various fields. The driving power supply is an indispensable part of LED lighting, and it is the key to ensure the quality and overall performance of LED lighting.

In the case of AC power supply, in order to meet the harmonic requirements of IEC61000-3-2, the LED driver must have a power factor correction function. For a high power factor LED drive power supply, the AC input voltage and current are in the same phase, the AC input instantaneous power contains twice the power frequency pulsation, and the output power is a constant value, which is equal to the average value of the input power. In order to balance the pulsating power between the AC input instantaneous power and the DC output instantaneous power, a large-capacity electrolytic capacitor is usually connected in parallel on the DC side.

Compared with long-life LED lamps, the service life of electrolytic capacitors is shorter, while the withstand voltage and capacitance of other types of capacitors are generally small, and electrolytic capacitors cannot be simply replaced. In the existing electrolytic capacitor-free LED drive power supply solutions, although the harmonic current injection method can realize electrolytic-free capacitorization, it reduces the power factor of the circuit; using inductors instead of capacitors as storage elements, although the reliability is high, but the volume increase, the cost increases. Therefore, the study of high power factor non-electrolytic capacitor LED driving power is of great significance to improve the quality of power consumption and prolong the service life of LED lamps.

SUMMARY OF THE INVENTION

In view of this, the purpose of the present invention is to propose a high power factor non-electrolytic capacitor LED driving power supply and a control method thereof, which can improve the quality of power consumption and prolong the service life of LED lamps.

The present invention adopts the following scheme to realize: a high power factor non-electrolytic capacitor LED driving power supply, comprising a first rectifier circuit B ₁ , an auxiliary circuit, two staggered parallel Boost circuits, an LED load, an input DC capacitor C _DC and an output capacitor C _O ;

The auxiliary circuit includes a first diode D ₁ , an auxiliary energy storage capacitor C ₁ , and an auxiliary circuit switch tube S ₃ ; the two-way interleaved parallel boost circuit includes a first inductor L ₁ , a second inductor L ₂ , a Two diodes D ₂ , a third diode D ₃ , a fourth diode D ₄ , a fifth diode D ₅ , the first switch S ₁ , the second switch S ₂ , the transformer T, the second rectifier circuit B ₂ ;

The input of the _first rectifier circuit B1 is connected to the AC power supply, and the positive output end of the _first rectifier circuit B1 is respectively connected to the anode of the first diode D1, _one end of the auxiliary energy storage capacitor _C1 and the input DC power one end of the capacitor C _DC , the negative output end of the _first rectifier circuit B1, the other end of the input DC capacitor C _DC , the source of the _first switch S1 and the _second switch S2 The sources of the first diode D1 are all grounded; the cathode of the _first diode D1 is respectively connected to one end of the first inductor L1, _one end of the _second inductor L2, and the source of the auxiliary circuit switch S3 _; the auxiliary circuit The other end of the energy storage capacitor _C1 is respectively connected to the drain _of the auxiliary circuit switch tube S3, the cathode of the _fourth diode D4, and the cathode of the _fifth diode D5; the other end of the _first inductor L1 One end is connected to the anode of the _second diode D2, the other end of the _second inductor L2 is connected to the anode of the third diode _D3 ; the cathodes of the _second diode D2 are respectively connected to the transformer The same-name terminal of the primary side of T, the anode of the _fifth diode D5, and the drain of the _first switch tube S1; the cathode of the third diode _D3 is connected to the primary side-named terminal of the transformer T, respectively The anode of the _fourth diode D4, the drain of the _second switch tube S2; the secondary side of the transformer T is connected to the input end of the _second rectifier circuit B2, the _second rectifier circuit B2 The output end is connected in parallel with the output capacitor _CO and the LED load.

Further, the voltage setting value of the auxiliary energy storage capacitor _C1 must be greater than N times the LED load voltage, so that when the _first switch S1 or the _second switch S2 is turned on, the fourth diode and the fifth diode are in the off state, where N is the turns ratio of the transformer T.

The present invention also provides a control method based on the power supply described above, specifically: detecting the output power of the _first rectifier circuit B1 and the output power of the LED driving power supply;

When the output power of the _first rectifier circuit B1 is greater _than the output power _of the LED driving power supply, the auxiliary circuit switch _S3 is controlled to be turned off, and the auxiliary circuit does not work. The switching frequency realizes the output constant current, and the excess energy is stored in the auxiliary energy storage capacitor _C1 by adjusting the dead time of the _first switch S1 and the _second switch S2;

When the output power of the first rectifier circuit B1 is less _than the output power of the LED driving power supply, the output constant current is realized by adjusting the switching frequency _of the _first switch tube S1 and the _second switch tube S2, and the auxiliary circuit switch tube S3 is in the first _A switch S1 or the _second switch S2 is turned on for a period of time before it is turned off, and by controlling the duty cycle _D of the auxiliary circuit switch S3, the auxiliary energy storage capacitor voltage _C1 is maintained within a power frequency cycle. set value.

Further, when the output power of the first rectifier circuit B1 is greater _than the output power of the LED driving power supply, the working process of the high power factor non-electrolytic capacitor LED driving power supply includes the following six modes:

Mode ₁ : The first switch S1 is turned on, the _second switch S2 is turned off, and the AC voltage is rectified by the _first rectifier circuit B1 and then passes through the _first diode D1, the _second diode D2, The _first switch S1 charges the _first inductor L1, and the _second inductor L2 releases energy to the LED load through the _first diode D1, the third diode _D3 , and the _first switch S1;

Mode 2: the current of the second inductor L ₂ decreases to 0, the third diode D ₃ is turned off, and the first inductor L ₁ continues to charge;

Mode 3: The first switch tube S ₁ is turned off, and the first inductor L ₁ is released to the auxiliary energy storage capacitor C ₁ through the first diode D ₁ , the second diode D ₂ , and the fifth diode D ₅ energy, the auxiliary energy storage capacitor C ₁ stores energy;

Mode 4: The _second switch S2 is turned on, the _first switch S1 is turned off, and the AC voltage is rectified by the _first rectifier circuit B1 and then passes through the _first diode D1, the third diode _D3 , The _second switch S2 charges the _second inductor L2, and the _first inductor L1 releases energy to the LED load through the _first diode D1, the _second diode D2, and the _second switch S2;

Mode 5: The current of the _first inductor L1 decreases to 0, the _second diode D2 is turned off, and the _second inductor L2 continues to charge;

Mode 6: The second switch S ₂ is turned off, and the second inductor L ₂ is released to the auxiliary energy storage capacitor C ₁ through the first diode D ₁ , the third diode D ₃ , and the fourth diode D ₄ energy, the auxiliary energy storage capacitor _C1 stores energy.

Further, when the output power of the first rectifier circuit B1 is less _than the output power of the LED driving power supply, the working process of the high power factor non-electrolytic capacitor LED driving power supply includes the following six modes:

Mode ₁ : The first switch S1 is turned on, the _second switch S2 is turned off, and the AC voltage is rectified by the _first rectifier circuit B1 and then passes through the _first diode D1, the _second diode D2, The _first switch S1 charges the _first inductor L1, and the _second inductor L2 releases energy to the LED load through the _first diode D1, the third diode _D3 , and the _first switch S1;

Mode 2: the current of the second inductor L ₂ decreases to 0, the third diode D ₃ is turned off, and the first inductor L ₁ continues to charge;

Mode ₃ : The auxiliary circuit switch S3 is turned on, the AC voltage is rectified by the _first rectifier circuit B1 and then connected to the auxiliary energy storage capacitor _C1 in series, and the auxiliary circuit switch _S3 , the _second diode D2, the first A switch tube S1 charges the _first inductor L1, and the auxiliary energy storage capacitor _C1 releases energy _;

Mode 4: The first switch S ₁ , the auxiliary circuit switch S ₃ are turned off, the second switch S ₂ is turned on, and the AC voltage is rectified by the first rectifier circuit B ₁ and then passes through the first diode D ₁ , the first The three diodes D ₃ and the second switch S ₂ charge the second inductor L ₂ , and the first inductor L 1 is charged to the second inductor L ₁ through the first diode D ₁ , the second diode D ₂ , and the second switch S ₂ . LED load releases energy;

Mode 5: The current of the _first inductor L1 decreases to 0, the _second diode D2 is turned off, and the _second inductor L2 continues to charge;

Mode ₆ : The auxiliary circuit switch S3 is turned on, the AC voltage is rectified and connected in series with the auxiliary energy storage capacitor _C1 , and the auxiliary circuit switch S3, the _third diode _D3 , and the _second switch S2 are paired The second inductor L ₂ is charged, and the auxiliary energy storage capacitor C ₁ releases energy.

Compared with the prior art, the present invention has the following beneficial effects: the present invention includes a rectifier circuit, a two-way staggered parallel boost circuit, an auxiliary circuit, an LED load, etc.; Correction function and constant current control; the auxiliary circuit is used to balance the difference between the instantaneous power of AC input and the instantaneous power of DC output, so as to avoid the use of large-capacity electrolytic capacitors, and film capacitors can be used instead of electrolytic capacitors to realize LED drive power without electrolytic capacitors; The coordinated control of the interleaved parallel boost circuit and the auxiliary circuit can realize low ripple output and constant current control of the LED load.

Description of drawings

FIG. 1 is a circuit diagram of a high power factor electrolytic capacitor-free LED driving power supply according to an embodiment of the present invention.

2 is a schematic diagram of driving waveforms of each switch tube when the output power of the first rectifier circuit B1 is greater _than the output power of the LED driving power supply according to an embodiment of the present invention.

3 is a schematic diagram of each working mode of the LED driving power supply when the output power of the first rectifier circuit B1 is greater _than the output power of the LED driving power supply according to the embodiment of the present invention.

4 is a schematic diagram of driving waveforms of each switch tube when the output power of the first rectifier circuit B1 is less _than the output power of the LED driving power supply according to an embodiment of the present invention.

5 is a schematic diagram of each working mode of the LED driving power supply when the output power of the first rectifier circuit B1 is less _than the output power of the LED driving power supply according to the embodiment of the present invention.

FIG. 6 is a schematic diagram of a control principle of a high power factor non-electrolytic capacitor LED driving power supply according to an embodiment of the present invention.

Detailed ways

The present invention will be further described below with reference to the accompanying drawings and embodiments.

It should be noted that the following detailed description is exemplary and intended to provide further explanation of the application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

It should be noted that the terminology used herein is for the purpose of describing specific embodiments only, and is not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly dictates otherwise, the singular is intended to include the plural as well, furthermore, it is to be understood that when the terms "comprising" and/or "including" are used in this specification, it indicates that There are features, steps, operations, devices, components and/or combinations thereof.

As shown in FIG. 1 , this embodiment provides a high power factor non-electrolytic capacitor LED driving power supply, including a first rectifier circuit B ₁ , an auxiliary circuit, two staggered parallel boost circuits, an LED load, an input DC capacitor C _DC and output capacitor C _O ;

The auxiliary circuit includes a first diode D ₁ , an auxiliary energy storage capacitor C ₁ , and an auxiliary circuit switch tube S ₃ ; the two-way interleaved parallel boost circuit includes a first inductor L ₁ , a second inductor L ₂ , a Two diodes D ₂ , a third diode D ₃ , a fourth diode D ₄ , a fifth diode D ₅ , the first switch S ₁ , the second switch S ₂ , the transformer T, the second rectifier circuit B ₂ ;

The input of the _first rectifier circuit B1 is connected to the AC power supply, and the positive output end of the _first rectifier circuit B1 is respectively connected to the anode of the first diode D1, _one end of the auxiliary energy storage capacitor _C1 and the input DC power one end of the capacitor C _DC , the negative output end of the _first rectifier circuit B1, the other end of the input DC capacitor C _DC , the source of the _first switch S1 and the _second switch S2 The sources of the first diode D1 are all grounded; the cathode of the _first diode D1 is respectively connected to one end of the first inductor L1, _one end of the _second inductor L2, and the source of the auxiliary circuit switch S3 _; the auxiliary circuit The other end of the energy storage capacitor _C1 is respectively connected to the drain _of the auxiliary circuit switch tube S3, the cathode of the _fourth diode D4, and the cathode of the _fifth diode D5; the other end of the _first inductor L1 One end is connected to the anode of the _second diode D2, the other end of the _second inductor L2 is connected to the anode of the third diode _D3 ; the cathodes of the _second diode D2 are respectively connected to the transformer The same-name terminal of the primary side of T, the anode of the _fifth diode D5, and the drain of the _first switch tube S1; the cathode of the third diode _D3 is connected to the primary side-named terminal of the transformer T, respectively The anode of the _fourth diode D4, the drain of the _second switch tube S2; the secondary side of the transformer T is connected to the input end of the _second rectifier circuit B2, the _second rectifier circuit B2 The output end is connected in parallel with the output capacitor _CO and the LED load.

In this embodiment, the voltage setting value of the auxiliary energy storage capacitor _C1 must be greater than N times the LED load voltage, so that when the _first switch S1 or the _second switch S2 is turned on, the fourth Both the diode and the fifth diode are in the off state, where N is the turns ratio of the transformer T.

The present embodiment also provides a control method based on the power supply described above, specifically: detecting the output power of the _first rectifier circuit B1 and the output power of the LED driving power supply;

When the output power of the _first rectifier circuit B1 is greater _than the output power _of the LED driving power supply, the auxiliary circuit switch _S3 is controlled to be turned off, and the auxiliary circuit does not work. The switching frequency realizes the output constant current, and the excess energy is stored in the auxiliary energy storage capacitor _C1 by adjusting the dead time of the _first switch S1 and the _second switch S2; among them, the driving waveform of each switch is shown in Figure 2 shown.

When the output power of the first rectifier circuit B1 is less _than the output power of the LED driving power supply, the output constant current is realized by adjusting the switching frequency _of the _first switch tube S1 and the _second switch tube S2, and the auxiliary circuit switch tube S3 is in the first _A switch S1 or the _second switch S2 is turned on for a period of time before it is turned off, and by controlling the duty cycle _D of the auxiliary circuit switch S3, the auxiliary energy storage capacitor voltage _C1 is maintained within a power frequency cycle. set value. Among them, the driving waveform of each switch tube is shown in FIG. 4 .

In this embodiment, when the output power of the first rectifier circuit B1 is greater _than the output power of the LED driving power supply, the working process of the high power factor non-electrolytic capacitor LED driving power supply includes the following six modes, as shown in FIG. 3 . Show:

Mode ₁ : The first switch S1 is turned on, the _second switch S2 is turned off, and the AC voltage is rectified by the _first rectifier circuit B1 and then passes through the _first diode D1, the _second diode D2, The _first switch S1 charges the _first inductor L1, and the _second inductor L2 releases energy to the LED load through the _first diode D1, the third diode _D3 , and the _first switch S1; as shown in the figure (a) in 3;

Mode 2: The current of the second inductor L ₂ is reduced to 0, the third diode D ₃ is turned off, and the first inductor L ₁ continues to charge; as shown in (b) in Figure 3

Mode 3: The first switch tube S ₁ is turned off, and the first inductor L ₁ is released to the auxiliary energy storage capacitor C ₁ through the first diode D ₁ , the second diode D ₂ , and the fifth diode D ₅ energy, the auxiliary energy storage capacitor _C1 stores energy; as shown in (c) in Figure 3;

Mode 4: The _second switch S2 is turned on, the _first switch S1 is turned off, and the AC voltage is rectified by the _first rectifier circuit B1 and then passes through the _first diode D1, the third diode _D3 , The _second switch S2 charges the _second inductor L2, and the _first inductor L1 releases energy to the LED load through the _first diode D1, the _second diode D2, and the _second switch S2; as shown in the figure (d) in 3;

Mode 5: The current of the first inductor L ₁ is reduced to 0, the second diode D ₂ is turned off, and the second inductor L ₂ continues to charge; as shown in (e) in Figure 3;

Mode 6: The second switch S ₂ is turned off, and the second inductor L ₂ is released to the auxiliary energy storage capacitor C ₁ through the first diode D ₁ , the third diode D ₃ , and the fourth diode D ₄ energy, the auxiliary energy storage capacitor _C1 stores the energy; as shown in (f) in Figure 3.

In this embodiment, when the output power of the first rectifier circuit B1 is less _than the output power of the LED driving power supply, the working process of the high power factor non-electrolytic capacitor LED driving power supply includes the following six modes, as shown in FIG. 5 . Show:

Mode ₁ : The first switch S1 is turned on, the _second switch S2 is turned off, and the AC voltage is rectified by the _first rectifier circuit B1 and then passes through the _first diode D1, the _second diode D2, The _first switch S1 charges the _first inductor L1, and the _second inductor L2 releases energy to the LED load through the _first diode D1, the third diode _D3 , and the _first switch S1; as shown in the figure (a) in 5;

Mode 2: the current of the second inductor L ₂ is reduced to 0, the third diode D ₃ is turned off, and the first inductor L ₁ continues to charge; as shown in (b) in Figure 5;

Mode ₃ : The auxiliary circuit switch S3 is turned on, the AC voltage is rectified by the _first rectifier circuit B1 and then connected to the auxiliary energy storage capacitor _C1 in series, and the auxiliary circuit switch _S3 , the _second diode D2, the first A switch tube S ₁ charges the first inductor L ₁ , and the auxiliary energy storage capacitor C ₁ releases energy; as shown in (c) in Figure 5;

Mode 4: The first switch S ₁ , the auxiliary circuit switch S ₃ are turned off, the second switch S ₂ is turned on, and the AC voltage is rectified by the first rectifier circuit B ₁ and then passes through the first diode D ₁ , the first The three diodes D ₃ and the second switch S ₂ charge the second inductor L ₂ , and the first inductor L 1 is charged to the second inductor L ₁ through the first diode D ₁ , the second diode D ₂ , and the second switch S ₂ . The LED load releases energy; as shown in (d) in Figure 5;

Mode 5: The current of the first inductor L ₁ is reduced to 0, the second diode D ₂ is turned off, and the second inductor L ₂ continues to charge; as shown in (e) in Figure 5;

Mode ₆ : The auxiliary circuit switch S3 is turned on, the AC voltage is rectified and connected in series with the auxiliary energy storage capacitor _C1 , and the auxiliary circuit switch S3, the _third diode _D3 , and the _second switch S2 are paired The second inductor L ₂ charges, and the auxiliary energy storage capacitor C ₁ releases energy; as shown in (f) in Figure 5.

Preferably, as shown in FIG. 6 , a digital controller can be used to collect the input and output power of the driving power supply, and generate a driving signal to control the work of each switch tube. The digital controller calculates the input power (ie the output power of the first rectifier bridge B ₁ ) by collecting the output voltage and current values of the first rectifier bridge B ₁ , and compares it with the voltage and current sampling values of the load (LED load) calculated from the sampled values. The output power of the LED driving power supply is compared. When the input power is greater _than the output power, the switch tube S3 is turned off, and the auxiliary circuit does not work. _The switching frequency _of the main circuit switch tubes S1 and S2 is adjusted by collecting the LED load current to achieve constant output. The excess energy is stored in the auxiliary energy storage capacitor C ₁ by adjusting the dead time of the switches S ₁ and S ₂ (the dead time is calculated from the input power and output power of the LED power supply); when the input power is less than the output power When the LED load current is collected, the switching frequency _of the main circuit switches S1 and _S2 is adjusted to realize the output constant current, and the voltage across the auxiliary energy storage capacitor _C1 is collected as the voltage feedback signal to generate the drive signal _of the switch S3. , control the switch tube _S3 to work, keep the voltage across the auxiliary energy storage capacitor _C1 at a set value in a power frequency cycle, thereby solving the problem of instantaneous power imbalance between the input and output of the LED drive power supply, and effectively reducing the output filter. The capacity of the capacitor can be replaced by a film capacitor instead of an electrolytic capacitor to achieve an electrolytic capacitor-free LED drive power supply.

As will be appreciated by those skilled in the art, the embodiments of the present application may be provided as a method, a system, or a computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the present application. It will be understood that each flow and/or block in the flowcharts and/or block diagrams, and combinations of flows and/or blocks in the flowcharts and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to the processor of a general purpose computer, special purpose computer, embedded processor or other programmable data processing device to produce a machine such that the instructions executed by the processor of the computer or other programmable data processing device produce Means for implementing the functions specified in one or more of the flowcharts and/or one or more blocks of the block diagrams.

These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory result in an article of manufacture comprising instruction means, the instructions An apparatus implements the functions specified in a flow or flows of the flowcharts and/or a block or blocks of the block diagrams.

These computer program instructions can also be loaded on a computer or other programmable data processing device to cause a series of operational steps to be performed on the computer or other programmable device to produce a computer-implemented process such that The instructions provide steps for implementing the functions specified in one or more of the flowcharts and/or one or more blocks of the block diagrams.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention in other forms. Any person skilled in the art may use the technical content disclosed above to make changes or modifications to equivalent changes. Example. However, any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solutions of the present invention still belong to the protection scope of the technical solutions of the present invention.

Claims (5)

1. a kind of High Power Factor no electrolytic capacitor LED drive power, it is characterised in that: including the first rectification circuit B₁, auxiliary electricity Road, two-way crisscross parallel Boost circuit, LED load, input direct-current capacitor C_DCAnd output capacitance C_O；

The auxiliary circuit includes first diode D₁, auxiliary energy storage capacitor C₁And auxiliary circuit switch pipe S₃；The two-way Crisscross parallel Boost circuit includes the first inductance L₁, the second inductance L₂, the second diode D₂, third diode D₃, the four or two pole Pipe D₄, the 5th diode D₅, first switch tube S₁, second switch S₂, transformer T, the second rectification circuit B₂；

The first rectification circuit B₁Input meet AC power source, the first rectification circuit B₁Positive output end be respectively connected to First diode D₁Anode, auxiliary energy storage capacitor C₁One end and input direct-current capacitor C_DCOne end, it is described first rectification Circuit B₁Negative output terminal, the input direct-current capacitor C_DCThe other end, the first switch tube S₁Source electrode and described Two switching tube S₂Source grounding；The first diode D₁Cathode be respectively connected to the first inductance L₁One end, second electricity The L of sense₂One end, auxiliary circuit switch pipe S₃Source electrode；The auxiliary energy storage capacitor C₁The other end be respectively connected to auxiliary electricity Way switch pipe S₃Drain electrode, the 4th diode D₄Cathode, the 5th diode D₅Cathode；The first inductance L₁The other end It is connected to the second diode D₂Anode, the second inductance L₂The other end be connected to third diode D₃Anode；Described Two diode D₂Cathode be respectively connected to the original side of the same name of transformer T, the 5th diode D₅Anode, first switch tube S₁ Drain electrode；The third diode D₃Cathode be respectively connected to the primary side different name end of transformer T, the 4th diode D₄Anode, Second switch S₂Drain electrode；The secondary side of the transformer T is connected to the second rectification circuit B₂Input terminal, described second Rectification circuit B₂Output end and be connected to output capacitance C_OAnd the LED load.

2. a kind of High Power Factor no electrolytic capacitor LED drive power according to claim 1, it is characterised in that: described Auxiliary energy storage capacitor C₁Voltage setting value be greater than N times of LED load voltage, wherein N for transformer T turn ratio.

3. a kind of control method based on High Power Factor no electrolytic capacitor LED drive power of any of claims 1 or 2, It is characterized in that: the first rectification circuit B of detection₁Output power and LED drive power output power；

As the first rectification circuit B₁Output power be greater than LED drive power output power when, control auxiliary circuit switch pipe S₃ Shutdown, auxiliary circuit do not work, by adjusting first switch tube S₁With second switch S₂Switching frequency realize output constant current, By adjusting first switch tube S₁With second switch S₂Dead time excess energy is stored in auxiliary energy storage capacitor C₁In；

As the first rectification circuit B₁Output power be less than LED drive power output power when, pass through adjust first switch tube S₁ With second switch S₂Switching frequency realize output constant current, auxiliary circuit switch pipe S₃In first switch tube S₁Or second switch Pipe S₂Shutdown is connected for the previous period, by controlling auxiliary circuit switch pipe S₃Duty ratio D, make auxiliary in a power frequency period Storage capacitor voltage C₁It is maintained at a setting value.

4. a kind of control method of High Power Factor no electrolytic capacitor LED drive power according to claim 3, feature It is: as the first rectification circuit B₁Output power be greater than LED drive power output power when, the High Power Factor is without electricity The course of work for solving capacitor LED drive power includes following six mode:

Mode 1: first switch tube S₁Conducting, second switch S₂Shutdown, alternating voltage is through the first rectification circuit B₁Pass through after rectification First diode D₁, the second diode D₂, first switch tube S₁To the first inductance L₁Charging, the second inductance L₂Pass through first diode D₁, third diode D₃, first switch tube S₁It releases energy to LED load；

2: the second inductance L of mode₂Electric current is reduced to 0, third diode D₃Cut-off, the first inductance L₁Continue to charge；

Mode 3: first switch tube S₁Shutdown, the first inductance L₁Pass through first diode D₁, the second diode D₂, the 5th diode D₅ To auxiliary energy storage capacitor C₁It releases energy, auxiliary energy storage capacitor C₁Store energy；

Mode 4: second switch S₂Conducting, first switch tube S₁Shutdown, alternating voltage is through the first rectification circuit B₁Pass through after rectification First diode D₁, third diode D₃, second switch S₂To the second inductance L₂Charging, the first inductance L₁Pass through first diode D₁, the second diode D₂, second switch S₂It releases energy to LED load；

5: the first inductance L of mode₁Electric current is reduced to 0, the second diode D₂Cut-off, the second inductance L₂Continue to charge；

Mode 6: second switch S₂Shutdown, the second inductance L₂Pass through first diode D₁, third diode D₃, the 4th diode D₄ To auxiliary energy storage capacitor C₁It releases energy, auxiliary energy storage capacitor C₁Store energy.

5. a kind of control method of High Power Factor no electrolytic capacitor LED drive power according to claim 3, feature It is: as the first rectification circuit B₁Output power be less than LED drive power output power when, the High Power Factor is without electricity The course of work for solving capacitor LED drive power includes following six mode:

Mode 1: first switch tube S₁Conducting, second switch S₂Shutdown, alternating voltage is through the first rectification circuit B₁Pass through after rectification First diode D₁, the second diode D₂, first switch tube S₁To the first inductance L₁Charging, the second inductance L₂Pass through first diode D₁, third diode D₃, first switch tube S₁It releases energy to LED load；

2: the second inductance L of mode₂Electric current is reduced to 0, third diode D₃Cut-off, the first inductance L₁Continue to charge；

Mode 3: auxiliary circuit switch pipe S₃Conducting, alternating voltage is through the first rectification circuit B₁After rectification with auxiliary energy storage capacitor C₁ Series connection, passes through auxiliary circuit switch pipe S₃, the second diode D₂, first switch tube S₁To the first inductance L₁Charging, auxiliary energy storage electricity Hold C₁It releases energy；

Mode 4: first switch tube S₁, auxiliary circuit switch pipe S₃Shutdown, second switch S₂Conducting, alternating voltage are whole through first Current circuit B₁Pass through first diode D after rectification₁, third diode D₃, second switch S₂To the second inductance L₂Charging, the first electricity Feel L₁Pass through first diode D₁, the second diode D₂, second switch S₂It releases energy to LED load；

5: the first inductance L of mode₁Electric current is reduced to 0, the second diode D₂Cut-off, the second inductance L₂Continue to charge；

Mode 6: auxiliary circuit switch pipe S₃Conducting, the rectified rear and auxiliary energy storage capacitor C of alternating voltage₁Series connection passes through auxiliary electricity Way switch pipe S₃, third diode D₃, second switch S₂To the second inductance L₂Charging, auxiliary energy storage capacitor C₁It releases energy.