CN112055448A - Flyback ripple suppression type electrolytic capacitor-free LED driving power supply - Google Patents
Flyback ripple suppression type electrolytic capacitor-free LED driving power supply Download PDFInfo
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- CN112055448A CN112055448A CN202010847946.7A CN202010847946A CN112055448A CN 112055448 A CN112055448 A CN 112055448A CN 202010847946 A CN202010847946 A CN 202010847946A CN 112055448 A CN112055448 A CN 112055448A
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
- H05B45/30—Driver circuits
- H05B45/345—Current stabilisation; Maintaining constant current
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
- H05B45/30—Driver circuits
- H05B45/355—Power factor correction [PFC]; Reactive power compensation
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
- H05B45/30—Driver circuits
- H05B45/36—Circuits for reducing or suppressing harmonics, ripples or electromagnetic interferences [EMI]
Abstract
The invention discloses an LED driving power supply based on Flyback ripple suppression type electrolytic-capacitor-free power supplies, and belongs to the technical field of power generation, power transformation or power distribution. The driving circuit comprises a full-bridge rectification filter circuit, a PFC (power factor correction) conversion circuit, a ripple suppression unit and a control unit. According to the invention, by constructing the isolated single-stage AC-DC converter, the LED driving circuit combining the PFC converter based on the Flyback circuit and the ripple suppression converter based on the full-bridge circuit, the ripple power decoupling is realized, the electrolytic capacitor is avoided, the energy cycle times in the circuit are reduced, the problem of out-of-control output voltage caused by instantaneous input power lower than required output power in a short time is solved, the requirements of no electrolytic capacitor, high power factor and high conversion efficiency are met, the service life of the LED driving power supply is prolonged, and the stability and efficiency of the LED driving power supply are improved.
Description
Technical Field
The invention discloses an LED driving power supply based on Flyback ripple suppression type electrolytic-capacitor-free power supply, relates to the design of an LED lighting driving power supply, and belongs to the technical field of power generation, power transformation or power distribution.
Background
Semiconductor Light Emitting Diodes (LEDs) have the advantages of high efficiency, long lifetime, environmental friendliness, and the like, and are widely used in various lighting applications. In the alternating current power supply occasion, the LED driving power supply needs to carry out input power factor correction, and because LED is as the load, its resistance is very little, and less ripple voltage will lead to great ripple current, takes place the stroboscopic, adopts the great electrolytic capacitor of appearance value to cushion usually, and the life of high quality electrolytic capacitor is far less than the life-span of LED chip. Therefore, in order to increase the service life of the LED driving power source, a capacitor for electrolysis needs to be removed.
Since the electrolytic capacitor is used to handle the unbalanced power between the input and output, the solution considered from the energy storage network itself mainly includes: the LED driving power supply is used for buffering double-frequency power based on a parallel structure and buffering double-frequency power based on a series structure, because the energy storage capacitor is not directly connected with the load in parallel, the capacitance value of the energy storage capacitor can be reduced in a mode of properly increasing direct current voltage or ripple voltage on the energy storage capacitor, so that the high-frequency capacitor with small capacitance value and long service life replaces an electrolytic capacitor, and the reliability of the LED driving power supply is improved.
At present, many researches are carried out to buffer double-frequency ripple power by analyzing an active power decoupling circuit, and based on the active power decoupling circuit with a parallel structure, when input power is greater than output power, redundant power is stored on an energy storage capacitor through the active power decoupling circuit, when the input power is less than the output power, the power stored in the energy storage capacitor compensates load through the active power decoupling circuit, and the minimum power processed by the active power decoupling circuit is double-frequency ripple power which is half; the active power decoupling circuit based on the series structure ensures that the alternating current component amplitudes of the ripple suppression capacitor and the energy storage capacitor are equal and the phases of the alternating current component amplitudes are opposite by controlling the active power decoupling circuit, so that the output current is constant, the power processed by the active power decoupling circuit is only very small ripple power, and the overall conversion efficiency of the LED driving power supply can be improved.
In an active power decoupling circuit topology based on a series structure, a capacitor is generally required to be introduced to the input side of the active power decoupling circuit to serve as an input source, and the active power decoupling circuit powered by an energy storage capacitor at the output side provides energy of the capacitor at the input side; or the input side of the active power decoupling circuit does not introduce a capacitor as an input source, and the alternating current input power supply directly provides energy to the active power decoupling circuit through the coupling inductor. Because the energy required for maintaining the voltage at the two ends of the input side of the active power decoupling circuit is from an alternating current input power supply, the hidden danger that the ripple eliminating capacitor voltage is out of control because the instantaneous input power is lower than the expected output power in a short time exists. At present, research has proposed that an auxiliary circuit is introduced to maintain the voltage of an input capacitor at a constant value, so as to ensure that the voltage of a ripple eliminating capacitor is not out of control, but the auxiliary circuit needs to additionally add a winding, a capacitor, a diode and the like, so that the circuit structure is complex, and the design cost and difficulty of driving are increased.
Disclosure of Invention
The invention aims to provide an LED driving power supply based on Flyback ripple suppression type electrolytic-capacitor-free, which can simultaneously meet the requirements of power factor correction and constant output current, has the advantages of no electrolytic capacitor, high power factor and high conversion efficiency, prolongs the service life of the LED driving power supply, improves the stability and the efficiency of the LED driving power supply, and solves the technical problem of potential hazard of capacitor voltage runaway caused by the fact that instantaneous input power is lower than expected output power in a short time in an active power decoupling circuit based on a series structure.
The invention adopts the following technical scheme for realizing the aim of the invention:
a Flyback ripple suppression type electrolytic capacitor-free LED driving power supply comprises: full-bridge rectification filter circuit, flyback PFC converter circuit, full-bridge circuit-based ripple suppression circuit, the control unit, wherein, flyback PFC converter circuit includes: the high-frequency transformer comprises a primary winding, a secondary main winding, a main power switch tube, a first power diode and an output energy storage capacitor; the ripple suppression unit includes: the high-frequency transformer comprises a secondary side auxiliary winding, a second power diode, a first power switch tube, a second power switch tube, a third power switch tube, a fourth power switch tube, an inductor and a ripple suppression capacitor; the control unit includes: a PFC controller and a ripple rejection controller. The single-phase alternating-current input power supply is connected with the middle point of a bridge arm of the full-bridge rectification filter circuit, a primary side circuit of the flyback PFC conversion circuit is connected to an output direct-current bus of the full-bridge rectification filter circuit, the flyback PFC conversion circuit is coupled with the ripple suppression unit, an output energy storage capacitor is connected with the ripple suppression capacitor in series, an LED load is connected to two ends of a series branch formed by the two capacitors in parallel, and a PFC controller in the control unit controls the output current of the LED driving power supply to realize circuit PFC; the ripple suppression controller controls ripple voltage at two ends of the ripple suppression capacitor, ripple suppression is achieved, and constant output current of the LED is achieved.
The positive output terminal of the direct current side of the full-bridge rectifier filter circuit is connected with one end of a primary winding of a high-frequency transformer, the negative output terminal of the direct current side of the full-bridge rectifier filter circuit is connected with the source electrode of a main power switch tube, the other end of the primary winding of the high-frequency transformer is connected with the drain electrode of the main power switch tube, one end of a secondary winding of the high-frequency transformer is connected with the anode of a first power diode, the cathode of the first power diode is connected with the positive electrode end of an output energy storage capacitor, the other end of the secondary winding of the high-frequency transformer is connected with the negative electrode end of the output energy storage capacitor, the positive electrode end of the output energy storage capacitor is connected with the anode of an LED load, one end of a secondary auxiliary winding of the high-frequency transformer is connected with the anode of a second power diode, the cathode of the second power diode is connected with the drain electrode of the first power switch tube and the drain electrode of a third The source electrode of the tube is connected, the source electrode of the first power switch tube and the drain electrode of the second power switch tube are connected with one end of the inductor, the other end of the inductor is connected with one end of the ripple suppression capacitor, and the source electrode of the third power switch tube, the drain electrode of the fourth power switch tube and the cathode of the LED load are connected with the other end of the ripple suppression capacitor. One end of the primary winding of the high-frequency transformer, which is connected with the drain electrode of the main power switch tube, and one end of the secondary winding of the high-frequency transformer, which is connected with the anode of the first power diode, are homonymous ends, and one end of the primary winding of the high-frequency transformer, which is connected with the drain electrode of the main power switch tube, and one end of the secondary winding of the high-frequency transformer, which is connected with the anode of the second power diode, are homonymous ends.
Designing turn ratio N of secondary main winding and auxiliary winding of high-frequency transformerS1:NS2To the output voltage ratio Vo1: Vo2Mismatch, the following relationship is satisfied: n is a radical ofS1:NS2<Vo1:Vo2When the ripple suppression unit does not work, the magnetic current flows to the secondary side main winding, and energy is transferred to the output energy storage capacitor to output a first output voltage; when the ripple suppression unit works, magnetic current flows to the auxiliary winding on the secondary side, and energy is transferred to the ripple suppression capacitor to output a second output voltage.
The control unit includes: the PFC controller works in a DCM mode and controls the main power switching tube to enable output current to follow reference current of the main power switching tube, so that circuit PFC is realized; the ripple suppression controller detects double-frequency ripple voltage in the first output voltage, the double-frequency ripple voltage is used as a reference value of the second output voltage after being inverted, all full-bridge power switching tubes in the ripple suppression unit are controlled through an accurately designed feedback loop to enable the second output voltage to follow the reference value of the second output voltage, ripple suppression is achieved, in each switching period, a carrier signal and a clock signal of the PFC controller are synchronized, and the ripple suppression controller is guaranteed to work under a correct time sequence.
The energy of the ripple suppression unit is not provided by the intermediate capacitor and is directly generated by the flyback PFC conversion circuit, so that the energy cycle number in the circuit is reduced; the energy that keeps ripple suppression electric capacity both ends voltage required comes from the AC input electricity in every switching cycle, exist in a certain period of time, instantaneous input power is less than required output power and leads to ripple suppression electric capacity both ends voltage out of control, introduce the full-bridge circuit among the ripple suppression unit, through the ripple suppression electric capacity voltage that produces the interchange, needn't add other auxiliary circuit and increase the direct current value that ripple suppression electric capacity voltage, directly offset ripple voltage, the energy transformation according to output energy storage capacitor in the unit cycle obtains output energy storage capacitor's appearance value expression:
ω＝2π/Tline，Tlinefor the period of the input AC voltage, PoTo output power, Vo1_aveFor outputting DC voltage, Δ V, of the storage capacitoro1For the ripple voltage of output energy storage capacitor, can be through producing suitable ripple voltage and direct current voltage to reduce energy storage capacitor appearance value, realize going electrolytic capacitor, output energy storage capacitor and ripple suppression electric capacity are high frequency capacitor in the circuit.
The alternating current component amplitude of voltage equals and opposite phase on ripple suppression electric capacity and the output energy storage electric capacity, makes load current be direct current output, and the last permission of output energy storage electric capacity has great ripple voltage peak value and its ripple component homoenergetic to offset through the voltage ripple component on the ripple suppression electric capacity, and the expression of instantaneous output power is on the ripple suppression electric capacity:
vo2(t) is the instantaneous voltage on the ripple rejection capacitor, and in order to ensure that the voltage on the ripple rejection capacitor is not out of control any more, it is always true that the instantaneous input power is greater than the instantaneous output power on the ripple rejection capacitor, that is:
by adopting the technical scheme, the invention has the following beneficial effects:
(1) the invention provides an LED driving power supply based on Flyback ripple suppression type electrolytic capacitor, which reduces the capacitance value of an energy storage capacitor by generating proper direct current voltage and ripple voltage on the energy storage capacitor, eliminates or reduces double frequency ripple of output current by replacing the electrolytic capacitor with a high-frequency capacitor, can realize power factor correction and constant output current at the same time, meets the requirements of LED driving characteristics, and prolongs the service life of LED driving.
(2) According to the Flyback ripple suppression type electrolytic capacitor-free LED driving power supply, the capacitor is not introduced into the energy input side of the ripple suppression unit to serve as an input source, energy is directly provided to the ripple suppression unit through the Flyback PFC conversion circuit and the coupling inductor, the energy cycle frequency in the circuit is reduced, the processing power of the active power decoupling circuit is further reduced, and the driving conversion efficiency is improved.
(3) The Flyback ripple suppression type electrolytic capacitor-free LED driving power supply provided by the invention solves the problem that the capacitor voltage is out of control in a short time due to the fact that the instantaneous input power is lower than the required output power, and improves the LED driving stability and efficiency.
Drawings
Fig. 1 is a circuit diagram of an LED driving power supply based on a Flyback ripple suppression type electrolytic capacitor-less according to the present invention.
Fig. 2(a) and fig. 2(b) are circuit diagrams of a PFC controller and a ripple suppression controller in an LED driving power control unit according to the present invention, respectively.
FIG. 3(a) and FIG. 3(b) are the ripple rejection capacitor voltage V in the power frequency cycleo2Schematic diagram of the cause of the runaway and schematic diagram of the principle of solving the voltage runaway by reducing the instantaneous output power on the ripple suppression capacitor.
Fig. 4 is a waveform diagram of the switching period of the LED driving power supply of the present invention.
Fig. 5 is an equivalent circuit diagram of an operating mode 1 of an LED driving power supply according to an embodiment of the invention.
Fig. 6 is an equivalent circuit diagram of the LED driving power supply working mode 2 according to the embodiment of the invention.
Fig. 7 is an equivalent circuit diagram of the operating mode 3 of the LED driving power supply according to the embodiment of the invention.
Fig. 8 is an equivalent circuit diagram of the LED driving power source working mode 4 according to the embodiment of the invention.
FIG. 9 shows an embodiment of the present invention in which the LED driving power supply operates at the input voltage VinInput voltage V at 110VAC/50HzinAnd an input current IinA waveform diagram of (a).
FIG. 10 shows the present inventionThe LED driving power supply of the embodiment works at an input voltage VinOutput voltage V at 110VAC/50HzOAnd an input current IOA waveform diagram of (a).
FIG. 11 shows an embodiment of the present invention in which the LED driving power supply operates at the input voltage VinOutput voltage V of energy storage capacitor when being 110VAC/50Hzo1And ripple suppression capacitor output voltage Vo2A waveform diagram of (a).
FIG. 12 shows an embodiment of the present invention in which the LED driving power supply operates at the input voltage VinAnd (3) a waveform diagram of the ripple suppression effect of the output voltage at 110VAC/50 Hz.
The reference numbers in the figures illustrate: 1 is a full-bridge rectification filter circuit, 2 is a flyback PFC conversion circuit, 3 is a ripple suppression unit, 4 is a control unit, 5 is an LED load, and Q is1Is a main power switch tube, S1、S2、S3、S4Is a first, a second, a third and a fourth power switch tube, NPIs a primary winding of a high-frequency transformer, NS1Is a secondary primary winding of a high-frequency transformer, NS2Is a secondary auxiliary winding of a high-frequency transformer, Dr1、Dr2、Dr3、Dr4Is a first, a second, a third and a fourth rectifying diode D1、D2Is a first and a second power diode, Co1For outputting energy-storage capacitors, Co2For ripple rejection capacitance, LfIs an inductor.
Detailed Description
The technical scheme of the invention is explained in detail in the following with reference to the attached drawings.
The invention discloses an LED driving power supply based on Flyback ripple suppression type electrolytic-capacitor-free LED driving power supply, as shown in figure 1, comprising: the device comprises a full-bridge rectification filter circuit 1, a flyback PFC conversion circuit 2, a ripple suppression unit 3 based on the full-bridge circuit, and a control unit 4 comprising a PFC controller and a ripple suppression controller. Single-phase ac input power supply VinThe full-bridge rectifier filter circuit 1 is connected with the middle point of a bridge arm, an output direct current bus of the full-bridge rectifier filter circuit 1 is connected with a primary side circuit of a flyback PFC (power factor correction) conversion circuit 2, the flyback PFC conversion circuit 2 is coupled with a ripple suppression unit 3, and PFC control in a control unit 4The controller controls the output current to realize the PFC of the circuit; the ripple suppression controller controls ripple voltage at two ends of the ripple suppression capacitor to realize ripple suppression, and the output energy storage capacitor is connected with the LED load to realize constant output current of the LED.
The full-bridge rectification filter circuit 1 includes: first rectifying diode Dr1And a second rectifying diode Dr2A bridge arm and a third rectifier diode D connected in seriesr3And a fourth rectifying diode Dr4The other bridge arm is formed.
The flyback PFC converter circuit 2 includes: primary winding N of high-frequency transformerPAnd main power switch tube Q1Primary circuit formed by connecting in series and secondary main winding N of high-frequency transformerS1A first power diode D1An output energy storage capacitor Co1A secondary main circuit, a direct current side positive output end of a full-bridge rectification filter circuit 1 and a primary winding N of a high-frequency transformer which are connected in seriesPIs connected to the primary winding N of the high-frequency transformerPThe other end of the main power switch tube Q1Is connected to the drain of the main power switch tube Q1The source of the high-frequency transformer is connected with the negative output end of the direct current side of the full-bridge rectification filter circuit 1, and the secondary side main winding N of the high-frequency transformerS1And a first power diode D1Is connected to the anode of a first power diode D1Cathode and output energy storage capacitor Co1Is connected with the positive polarity end of the output energy storage capacitor Co1Negative terminal of and secondary main winding N of high-frequency transformerS1Is connected with the other end of the output energy storage capacitor Co1Is connected to the anode of the LED load.
The ripple suppression unit 3 includes: secondary auxiliary winding N of high-frequency transformerS2A second power diode D2A first power switch tube S1A second power switch tube S2The third power switch tube S3The fourth power switch tube S4Inductor LfRipple suppression capacitor Co2Secondary auxiliary winding N of high-frequency transformerS2And a second power diode D2Is connected to the anode of a second power diode D2Cathode, first power switchClosing pipe S1Drain electrode of the third power switch tube S3Is connected with the drain electrode of the high-frequency transformer, and a secondary side auxiliary winding N of the high-frequency transformerS2Another end of the first power switch tube S2Source electrode of, fourth power switch tube S4Is connected with the source electrode of the first power switch tube S1Source electrode of the first power switch tube S2Drain electrode of (1), inductor LfIs connected to one end of an inductor LfAnother terminal of (1) and ripple rejection capacitor Co2Is connected to the positive terminal of the third power switch tube S3Source electrode of, fourth power switch tube S4Drain electrode of (1), ripple suppression capacitor Co2Is connected with the negative end and outputs an energy storage capacitor Co1Negative terminal and ripple rejection capacitor Co2Is connected to the positive terminal of the ripple rejection capacitor Co2Is connected to the negative pole of the LED load. Primary winding N of high-frequency transformerPAnd main power switch tube Q1One end of the drain electrode is connected with the secondary side main winding N of the high-frequency transformerS1And a first power diode D1The ends connected with the anode are the same name ends, and the primary winding N of the high-frequency transformerPAnd main power switch tube Q1One end of the drain electrode is connected with the auxiliary winding N of the secondary side of the high-frequency transformerS2And a second power diode D2The ends of the anode connected are the same name ends.
The Flyback ripple suppression type electrolytic capacitor-free LED driving power supply shown in figure 1 is designed to have a turn ratio N of a high-frequency transformerS1:NS2Voltage to voltage ratio Vo1:Vo2Mismatch, the following relationship is satisfied: n is a radical ofS1:NS2<Vo1: Vo2High frequency transformer in main power switch tube Q1The main power switch tube Q is electrified in the conduction time1After the power supply is turned off, the magnetic current needs to be kept flowing, and when the ripple suppression unit 3 does not work, the magnetic current flows to the secondary side main winding NS1The winding inductance is denoted Lmag_NS1Energy is transferred to the output storage capacitor Co1Output Vo1(ii) a When the ripple suppression unit 3 operates, a magnetic current flows to the secondary auxiliary winding NS2The winding inductance is denoted Lmag_NS2To be able toThe quantity is transferred to the ripple rejection capacitor Co2Output Vo2。
The control unit includes: fig. 2(a) is a schematic diagram of a PFC controller circuit, and fig. 2(b) is a schematic diagram of a ripple rejection controller circuit. The flyback PFC controller works in a DCM mode and controls a main power switch tube Q1To make the output current IoRealizing a circuit PFC following the reference current; ripple rejection controller detects Vo1The ripple voltage is used as output V after being invertedo2Reference voltage V ofo2_refControlling a full-bridge power switch tube S through an accurately designed feedback loop1-S4，Vo2And the reference voltage is followed to realize ripple suppression, and in each switching period, a carrier signal and a clock signal of the PFC controller are synchronized, so that the ripple suppression controller is ensured to work under a correct time sequence.
FIG. 3(a) shows ripple rejection capacitor C in the power frequency cycleo2Voltage Vo2The reason for runaway is schematically shown in FIG. 3(b) for suppressing the capacitance C by reducing the rippleo2Instantaneous output power Po2(t) schematic diagram for solving voltage runaway principle. Maintaining voltage V across ripple rejection capacitoro2The energy required is from the ac input source V in each switching cycleinExistence of [ ta,tb]Instantaneous input power P in timein(t) is less than Vo2(t) required instantaneous output Power Po2(t), resulting in an output Vo2Runaway, as shown in FIG. 3 (a). The ripple suppression unit 3 of the present invention generates AC V through a full bridge circuito2No need of adding other auxiliary circuits to increase Vo2DC value of the capacitor C for suppressing rippleo2Instantaneous output power Po2(t) is decreased to ensure at [ ta,tb]The internal power curve is shown in FIG. 3(b), and is higher than the instantaneous input power P only for a small timein(t), which can be approximately ignored, under which condition Vo2There is almost no runaway, thereby optimizing the ripple suppression effect.
Fig. 4 is a waveform diagram in a unit switching period, fig. 5 to 8 are working modes in the unit switching period, each switching period has 4 time intervals, namely 4 working modes, and the LED driving power supply periodically works in sequence from working mode 1 to working mode 4.
FIG. 5 shows the working mode 1[ t ]0-t1]When the main power switch tube Q1On, the switching cycle is from time t0And starting. A primary winding of the high-frequency transformer obtains energy from alternating current input, and primary current rises from zero; when main power switch tube Q1At turn-off, the interval between the segments is at t1And (6) ending. During this time, the main power switch tube Q1The peak input switch current of (a) may be calculated as follows:
Tonis a main power switch tube Q1On-time of Lmag_NPPrimary winding N of high-frequency transformerPThe average input current I of the switching cyclein_avg(t) and Peak switching Current Iin_pk(t) the relational expression is:
TSis the switching period, and the effective value V of the input voltage is assumed to be zero power lossin_rmsInput current effective value Iin_rmsAnd the output power POThe relational expression between them is:
main power switch tube Q under instantaneous voltage1Peak switching current I ofQ1_pkThe expression of (t) is:
first power diode D1Reverse voltage V acrossD1_RCan be expressed as: vD1_R＝Vin(t)+Vo1(t), a second power diode D2Reverse voltage V acrossD2_RCan be expressed as:
FIG. 6 shows the working mode 2[ t ]1-t2]Main power switch tube Q1Is turned off and the ripple suppression unit is still not operating. Connecting only the secondary primary winding N of the high-frequency transformerS1A first power diode D1And an output energy storage capacitor Co1The circuit of (a) provides a freewheeling loop for the transformer current. Therefore, during this time interval, the transformer inductance energy is transferred to the output energy storage capacitor, output Vo1. First power diode D1The peak switch current in the main power switch tube Q is equal to1Medium peak switching current, main power switching tube Q1Voltage V acrossds_Q1Expression (c): vds_Q1＝Vin(t)+Vo1(t) because of the secondary auxiliary winding N of the high-frequency transformerS2The voltage of both ends is higher than the voltage V of the ripple suppression capacitoro2(t), therefore the second power diode D2Forward bias, voltage V at two ends of full-bridge ripple suppression circuitds_FBCan be expressed as:
FIG. 7 shows the working mode 3[ t ]2-t3]When the control signal vcAnd a carrier signal Vtr2At t when overlapping2At the moment, the ripple suppression unit starts to work, and the high-frequency transformer current starts to flow from the secondary side main winding NS1Commutation secondary auxiliary winding NS2. Thus, the residual inductive energy of the high-frequency transformer is transferred to the ripple-suppression capacitor, and the output Vo2. Secondary auxiliary winding NS2Is proportional to the square of the number of turns and can be expressed as:
main power switch tube Q1Voltage Vds_Q1Expression (c):
first power diode D1Voltage VD1_RExpression (c):
FIG. 8 shows the working mode 4[ t ]3-t4]To achieve high power factor, the flyback PFC converter circuit is designed to operate in DCM. There is a very short time interval t before the start of the next switching cycle3-t4]The high frequency transformer current remains zero until the next switching cycle. Since the magnetic current is already zero, the state of the ripple suppression unit is not important in this time interval. The ripple suppression unit may also be turned off during time intervals, if desired.
The above operation illustrates that the Flyback ripple suppression type electrolytic capacitor-free LED driving power supply of the present invention realizes single-stage power conversion. At time intervals t0-t1]And energy is transmitted from an alternating current power supply to a primary winding of the high-frequency transformer. At time intervals t1-t2]The high-frequency transformer will transfer most of its energy to output Vo1. At time intervals t2-t3]During this period, the high-frequency transformer transfers its residual energy to the output Vo2. In one switching cycle, the high frequency transformer is only charged and discharged once, while energy is transferred from the input to the output.
FIG. 9 shows an embodiment of the present invention in which the LED driving power supply operates at the input voltage Vin110VAC/50Hz, input voltage VinInput current IinAnd (4) waveform diagrams. Designing the main power switch Q1Operating frequency fs_Q1100kHz, first to fourth power switch tubes S1-S4Operating frequency fs_FB100kHz, high frequency transformer NP:NS1:NS280:80:40, output energy storage capacitor Co160uF, ripple rejection capacitor Co222uF, inductance LfAt 28uH, output power PoIt was 17.5W. Input voltage VinInput current IinThe waveform diagram verifies that the proposed LED driving power supply implements PFC.
FIG. 10 shows the operation of the LED driving power supply according to the embodiment of the present inventionAt an input voltage Vin110VAC/50Hz, output voltage VOInput current IOAnd (4) waveform diagrams. Designing parameters of the LED driving power supply as above, the average value V of the output voltage is verifiedo50VDC, average value of output current IoThe ripple suppression is basically realized under the condition of no electrolytic capacitor, and the LED driving design requirement is met.
FIG. 11 shows an embodiment of the present invention in which the LED driving power supply operates at the input voltage Vin110VAC/50Hz, output energy storage capacitor Co1Output voltage Vo1And ripple suppression capacitor Co2Output voltage Vo2The waveform diagram shows the voltage value in the control circuit, namely the voltage value is sampled by 0.1 time, the ripple suppression of the LED driving power supply can be realized, and simultaneously V is showno2The voltage can not be out of control and well follows the given voltage Vo2_ref。
FIG. 12 shows an embodiment of the present invention in which the LED driving power supply operates at the input voltage Vin110VAC/50Hz, ripple suppression effect waveform diagram of output voltage, and output voltage (V) without ripple suppression unito1-Vo2) Comparing the waveforms, the actual output waveform VoThe ripple voltage is obviously reduced, the LED driving power supply is verified to have good ripple rejection capability, and the stability of the LED driving power supply is improved.
Claims (6)
1. An LED drive power supply based on Flyback ripple suppression type electrolytic-capacitor-free LED drive power supply is characterized by comprising:
the middle point of a bridge arm of the full-bridge rectification filter circuit is connected with a single-phase alternating current input power supply;
a primary side branch of the flyback PFC conversion circuit is connected between a positive and negative polarity direct current output bus of the full-bridge rectification filter circuit to form a primary side loop, and a secondary side branch of the flyback PFC conversion circuit is connected in series with an output energy storage capacitor to form a secondary side loop;
the ripple suppression unit is used for converting partial energy coupled from the primary side loop of the flyback PFC converter into ripple voltage and applying the ripple voltage to a ripple suppression capacitor connected to an output port, the ripple suppression capacitor is connected with the output energy storage capacitor in series to form the output port of the LED driving circuit, and the amplitude of the alternating current component of the voltage of the ripple suppression capacitor is equal to that of the alternating current component of the voltage of the output energy storage capacitor and the phase of the alternating current component of the voltage of the output energy storage capacitor is opposite; and a process for the preparation of a coating,
and the control unit is used for carrying out closed-loop control on the output current of the LED driving circuit, generating a primary side loop switch control signal of the flyback PFC conversion circuit working in a DCM mode, extracting frequency-doubled ripple voltage from the output energy-storage capacitor voltage, inverting the frequency-doubled ripple voltage, generating a ripple suppression capacitor voltage reference value, and generating a ripple suppression unit switch control signal of which the ripple suppression capacitor voltage follows the reference value.
2. The Flyback ripple suppression type electrolytic capacitor-free LED driving power supply as claimed in claim 1, wherein the primary loop of the Flyback PFC conversion circuit comprises: the high-frequency transformer primary winding comprises a high-frequency transformer primary winding and a main power switch tube, wherein one end of the high-frequency transformer primary winding is connected with a positive polarity direct current output bus of a full-bridge rectification filter circuit; the secondary side loop of the flyback PFC converter circuit comprises: the high-frequency transformer comprises a high-frequency transformer secondary winding, a first power diode and an output energy storage capacitor, wherein one end of the high-frequency transformer secondary winding is connected with the anode of the first power diode, the cathode of the first power diode is connected with the positive end of the output energy storage capacitor, the negative end of the output energy storage capacitor is connected with the other end of the high-frequency transformer secondary main winding, and one end of the high-frequency transformer primary winding, which is connected with the drain electrode of a main power switch tube, and one end of the high-frequency transformer secondary main winding, which is connected with the anode of the first power diode, are homonymous ends.
3. The Flyback ripple suppression type electrolytic capacitor-less LED driving power supply according to claim 2, wherein the ripple suppression unit comprises: the high-frequency transformer secondary side auxiliary winding comprises a high-frequency transformer secondary side auxiliary winding, a second power diode, a full-bridge inverter circuit, an inductor and a ripple suppression capacitor, wherein one end of the high-frequency transformer secondary side auxiliary winding is connected with the anode of the second power diode, the cathode of the second power diode is connected with a common junction of a bridge arm of the full-bridge inverter circuit, the other end of the high-frequency transformer secondary side auxiliary winding is connected with a common junction of another bridge arm of the full-bridge inverter circuit, a branch formed by serially connecting the inductor and the ripple suppression capacitor is connected to the midpoint of the bridge arm of the full-bridge inverter circuit, and the end, connected with the drain electrode of a main power switch tube, of the high-frequency transformer primary side winding and the end.
4. The Flyback ripple suppression type electrolytic capacitor-free LED driving power supply as claimed in claim 1, wherein the turn ratio N of the secondary side main winding to the auxiliary winding of the high-frequency transformer isS1:NS2And the voltage ratio V of the secondary side output of the flyback PFC conversion circuit to the output of the ripple suppression unito1:Vo2Mismatch, the following relationship is satisfied: n is a radical ofS1:NS2<Vo1:Vo2。
5. The Flyback ripple suppression type electrolytic capacitor-less LED driving power supply as claimed in claim 1, wherein the power supply is based on the expression:
determining the capacitance value C of an output energy-storage capacitoro1，ω＝2π/Tline，TlinePeriod of AC voltage output for single-phase AC input power supply, PoIs the output power of the LED drive circuit, Vo1_aveFor outputting DC voltage, Δ V, of the storage capacitoro1To output the ripple voltage of the energy storage capacitor.
6. The Flyback ripple suppression type electrolytic capacitor-free LED driving power supply as claimed in claim 5, wherein the Flyback ripple suppression type electrolytic capacitor-free LED driving power supply is based on the instantaneous input power Pin(t) is greater than ripple rejection capacitance Co2Upper instantaneous output power Po2(t), i.e., according to the relationship:
determining a suitable output energy storage capacitor Co1Ripple voltage Δ V ofo1Value of (a), pin(t)minIs the minimum value of instantaneous input power, po2(t)maxCapacitor C for suppressing rippleo2Maximum value of upper instantaneous output power, VoAnd outputting voltage for the LED driving circuit.
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112867204A (en) * | 2021-02-08 | 2021-05-28 | 杭州优特电源有限公司 | Auxiliary power supply |
| CN114205954A (en) * | 2021-12-30 | 2022-03-18 | 福州大学 | Electrolytic-capacitor-free control method for improved Sepic-LED driving circuit |
| CN114679816A (en) * | 2021-12-31 | 2022-06-28 | 福州大学 | Intermediate capacitor current control method for electrolytic capacitor-free single-stage LED drive circuit |
| WO2022248329A1 (en) | 2021-05-28 | 2022-12-01 | Signify Holding B.V. | A driver for driving a load, such as a led load |
| CN117595644A (en) * | 2024-01-18 | 2024-02-23 | 武汉理工大学 | Electrolytic capacitor-free V2G converter based on ripple reverse compensation |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN204652713U (en) * | 2015-02-15 | 2015-09-16 | 深圳市天绿地节能环保科技有限公司 | A kind of LED drive power of no electrolytic capacitor |
| CN105517253A (en) * | 2016-01-27 | 2016-04-20 | 福州大学 | Compound auxiliary winding TiBuck-Flyback single-stage LED driving circuit |
| CN105871194A (en) * | 2016-05-31 | 2016-08-17 | 福州大学 | Step-down Cuk/Flyback single-stage low-ripple-wave LED drive circuit based on flyback converter auxiliary winding |
| CN106332355A (en) * | 2016-09-06 | 2017-01-11 | 上海大学 | Non-isolated non-electrolytic capacitor LED driving power supply based on Boost and Flyback circuit integration |
| CN108601146A (en) * | 2018-05-11 | 2018-09-28 | 福州大学 | A kind of high-power factor and output ripple and low Flyback/Sepic LED drive circuits |
| CN110536517A (en) * | 2019-09-27 | 2019-12-03 | 福州大学 | A kind of single-stage isolated type no electrolytic capacitor LED drive power and its control method |
| CN111432524A (en) * | 2020-04-15 | 2020-07-17 | 福州大学 | Single-stage non-isolated high-power-factor electrolytic-capacitor-free L ED driving power supply |
-
2020
- 2020-08-21 CN CN202010847946.7A patent/CN112055448B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN204652713U (en) * | 2015-02-15 | 2015-09-16 | 深圳市天绿地节能环保科技有限公司 | A kind of LED drive power of no electrolytic capacitor |
| CN105517253A (en) * | 2016-01-27 | 2016-04-20 | 福州大学 | Compound auxiliary winding TiBuck-Flyback single-stage LED driving circuit |
| CN105871194A (en) * | 2016-05-31 | 2016-08-17 | 福州大学 | Step-down Cuk/Flyback single-stage low-ripple-wave LED drive circuit based on flyback converter auxiliary winding |
| CN106332355A (en) * | 2016-09-06 | 2017-01-11 | 上海大学 | Non-isolated non-electrolytic capacitor LED driving power supply based on Boost and Flyback circuit integration |
| CN108601146A (en) * | 2018-05-11 | 2018-09-28 | 福州大学 | A kind of high-power factor and output ripple and low Flyback/Sepic LED drive circuits |
| CN110536517A (en) * | 2019-09-27 | 2019-12-03 | 福州大学 | A kind of single-stage isolated type no electrolytic capacitor LED drive power and its control method |
| CN111432524A (en) * | 2020-04-15 | 2020-07-17 | 福州大学 | Single-stage non-isolated high-power-factor electrolytic-capacitor-free L ED driving power supply |
Non-Patent Citations (5)
| Title |
|---|
| MAODONG TANG等: "Elimination of Electrolytic Capacitor in AC/DC LED Driver with Ripple Cancellation Based on Series Compensation Structure", 《2021 IEEE 1ST INTERNATIONAL POWER ELECTRONICS AND APPLICATION SYMPOSIUM (PEAS)》 * |
| WU CHEN等: "Elimination of an Electrolytic Capacitor in AC/DC Light-Emitting Diode (LED) Driver With High Input Power Factor and Constant Output Current", 《IEEE TRANSACTIONS ON POWER ELECTRONICS》 * |
| 史永胜等: "单级PFC反激式LED电源的研究与设计", 《光电子技术》 * |
| 徐茜: "《中国优秀博硕士学位论文全文数据库(硕士)工程科技Ⅱ辑》", 15 June 2022 * |
| 柯顺元等: "一种减少输出纹波的单级反激LED驱动电路", 《电源学报》 * |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112867204A (en) * | 2021-02-08 | 2021-05-28 | 杭州优特电源有限公司 | Auxiliary power supply |
| CN112867204B (en) * | 2021-02-08 | 2023-04-18 | 杭州优特电源有限公司 | Auxiliary power supply |
| WO2022248329A1 (en) | 2021-05-28 | 2022-12-01 | Signify Holding B.V. | A driver for driving a load, such as a led load |
| CN114205954A (en) * | 2021-12-30 | 2022-03-18 | 福州大学 | Electrolytic-capacitor-free control method for improved Sepic-LED driving circuit |
| CN114679816A (en) * | 2021-12-31 | 2022-06-28 | 福州大学 | Intermediate capacitor current control method for electrolytic capacitor-free single-stage LED drive circuit |
| CN114679816B (en) * | 2021-12-31 | 2023-05-23 | 福州大学 | Intermediate capacitance current control method for single-stage LED driving circuit without electrolytic capacitor |
| CN117595644A (en) * | 2024-01-18 | 2024-02-23 | 武汉理工大学 | Electrolytic capacitor-free V2G converter based on ripple reverse compensation |
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