CN210899756U

CN210899756U - Novel magnetic integration low-input ripple current LED driving power supply

Info

Publication number: CN210899756U
Application number: CN201922069930.3U
Authority: CN
Inventors: 石勇; 冯浪浪; 李启凡; 宋扬
Original assignee: Shaanxi University of Science and Technology
Current assignee: Shaanxi University of Science and Technology
Priority date: 2019-11-26
Filing date: 2019-11-26
Publication date: 2020-06-30
Anticipated expiration: 2029-11-26

Abstract

The utility model discloses a novel integrated low input ripple current's of magnetism LED drive power supply, because current circuit is comparatively complicated, input current's ripple is great, needs great filter circuit, consequently, on the basis of original circuit topology, the improvement has become the integrated low input ripple current's of present novel magnetism LED drive power supply. And the novel circuit has simple circuit and small input current ripple. The LED driving power supply has two important indexes, namely power factor and efficiency, the design of the circuit realizes the correction of the power factor by controlling the on and off of two switching tubes, thereby realizing the maximization of the efficiency, realizing the aim of reducing the ripple wave of the input current by inductance and capacitance filtering, and ensuring that the parameters and indexes of the novel circuit achieve better effect.

Description

Novel magnetic integration low-input ripple current LED driving power supply

Technical Field

The utility model belongs to the technical field of low input current ripple AC-DC converter, concretely relates to novel integrated low input ripple current's of magnetism LED drive power supply.

Background

The LED lighting system is a novel lighting source system, has the advantages of remarkable energy conservation and emission reduction, and has comprehensively replaced the traditional light source. In LED lighting systems, the performance and efficiency of their driving power supplies is critical. The LED driving power has two important criteria, one is input power factor and the other is efficiency. It is important to find a circuit topology that is low in cost and has high efficiency and high power factor characteristics.

In recent two years, the LED lighting industry and related products thereof have made great breakthroughs in technology. With the widespread use of LEDs in people's lives and in underdeveloped areas, LEDs exhibit superior developmental advantages. Although the application of the LED light source in the field of common illumination is only a brand-new head corner, with the forward development of scientific technology, the luminous efficiency of the LED is also required to be continuously improved, meanwhile, the production cost is also greatly reduced, and the LED serving as a leader of the field of illumination in the century is unquestionable due to the inherent advantages of the LED.

The LED switching power supply is going to be miniaturized and high frequency, and the higher the frequency is, the smaller the switching power supply is. The switching power supply is therefore used in a wider range of applications, especially in high and new technology, and also in high and new technology products, more lightweight and compact. In addition, the application and development of the switching power supply technology also relatively save resources and energy.

Fig. 1 is a schematic diagram of a conventional high power factor LED driving power supply, which has the following problems: two-stage conversion, the circuit is complex; the Boost capacitor VA has large capacity; the circuit is complex, the input current ripple is large, and a large filter circuit is needed; magnetic elements cannot be designed in an integrated manner.

Disclosure of Invention

The utility model provides a novel integrated low input ripple current's of magnetism LED drive power supply does not need solitary power factor to rectify, has realized the single-stage transform, has simplified the circuit to the input current ripple is little.

In order to achieve the above object, the novel magnetically integrated LED driving power supply with low input ripple current comprises an AC/DC rectifier circuit, an LC filter circuitTransformer T₁Rectifier circuit and voltage stabilizing capacitor C_oSaid transformer T₁Primary side first winding N_p1Is connected with the drain electrode of the switch tube S1, and the transformer T₁Primary side secondary winding N_p2Is connected with the drain electrode of the switch tube S2, and the transformer T₁Primary side first winding N_p1End of same name and transformer T₁Primary side secondary winding N_p2The homonymous terminals of the two terminals are connected; the LC filter circuit comprises an energy storage inductor L₁Inductor L₂Inductor L₃And a capacitor Cs, the energy storage inductor L₁The inductor L2 and the inductor L3 are coupled to the transformer T₁In the magnetic core of (2).

Further, an inductance L₂Inductor L₃Is connected with the capacitor Cs in series to form a series branch circuit, and the series branch circuit and the transformer T are connected₁Primary side secondary winding N_p2And a switching tube S2, the energy storage inductor L₁End of synonym and inductance L₂The synonym end of (2) is connected.

Further, a transformer T₁Is a push-pull transformer.

Further, the AC/DC rectification circuit is a full-bridge rectification circuit.

Further, the on-time sequence of the switch tube S1 and the switch tube S2 is: switch tube S1 and switch tube S2 are turned on simultaneously, switch tube S1 is turned on and switch tube S2 is turned off, switch tube S1 and switch tube S2 are both turned on, switch tube S1 is turned off and switch tube S2 is turned on.

Further, the switching tube S1 and the switching tube S2 are MOS tubes.

Compared with the prior art, the utility model discloses following profitable technological effect has at least:

1) all magnetic elements can be designed in an integrated mode, so that extra filter inductance is not needed to be added to output, and the size can be effectively reduced.

2) The PFC and the DC/DC are combined together, so that the independent PFC is not needed, single-stage conversion is realized, and the circuit is simple;

3) pass through the filter circuit, so that the input current ripple is reduced, and push-pullThe ripple of the current and voltage output by the transformer is very small, so that no filter circuit is additionally added on the secondary side of the transformer, and C_sThe current stress is small; the input current has small ripple waves, and a large filter circuit is not needed;

4) and (3) realizing power factor correction: the processes of energy storage and energy release of the inductor are alternately performed by switching on and off the switching tube, so that the current well follows the change of the voltage waveform, and the current is sinusoidal, thereby achieving the function of power factor correction.

Drawings

FIG. 1 is a schematic diagram of a conventional high power factor LED driving power supply;

FIG. 2 is a schematic diagram of a novel magnetically integrated low input ripple current LED drive power supply;

FIG. 3 is a schematic diagram of an integrated magnetic original device;

FIG. 4 is a schematic diagram of an idealized operating waveform of the circuit;

FIG. 5 is a schematic view of the operational mode;

FIG. 6 is a schematic view of the second mode of operation;

fig. 7 is a schematic diagram of the third operation mode.

Detailed Description

In order to make the purpose and technical scheme of the utility model clearer and more convenient to understand. The present invention will be described in further detail with reference to the following drawings and examples, wherein the specific examples are provided for the purpose of illustration only and are not intended to be limiting.

In the description of the present invention, it is to be understood that the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless otherwise specified. In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the term "connected" is to be interpreted broadly, for example, as a fixed connection, a detachable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Referring to fig. 2, the novel magnetically integrated low-input ripple current LED driving power supply comprises an AC/DC rectifier, an LC filter circuit and a push-pull transformer T₁Rectifier circuit, voltage-stabilizing capacitor Co and switch tube S₁And a switching tube S₂By controlling the switching tube S₁And a switching tube S₂Is switched on and off to realize power factor correction through the transformer T₁To realize the conversion of DC/DC to provide a stable DC voltage to the load, a stabilizing capacitor Co is added across the load.

The AC/DC rectifier is a full-bridge rectifier circuit comprising a diode D₁Diode D₂Diode D₃And a diode D₄Diode D₁Diode D₂In the same bridge arm, diode D₃And a diode D₄In the same bridge arm. The LC filter circuit comprises an energy storage inductor L₁Inductor L₂Inductor L₃And a capacitor Cs, the rectifying circuit including a capacitor connected to the transformer T₁Secondary side diode D0₁And a diode D₀₂。

Cathode of diode D3 and energy storage inductor L₁Is connected with the same name end of the inductor L₁End of synonym and inductance L₂End of different name, transformer T₁Primary side first winding N_p1End of same name and transformer T₁Primary side secondary winding N_p2The homonymous terminals of the two terminals are connected; inductor L₂End of same name and inductance L₃Is connected with the same name end of the inductor L₃The second end of the capacitor Cs is connected with the anode of the diode D4, the source of the switch tube S1 and the switch tube S2, the drain of the switch tube S1 is connected with the transformer T₁Primary side first winding N_p1Is connected with the different name end of the switch tube S2, the drain electrode of the switch tube S2 and the transformer T₂Primary side secondary winding N_p2The different name ends of the two groups are connected; transformer T₁Secondary side first winding N_s1Dotted terminal of and diode D_o1Is connected to the anode of diode D_o1And diode D_o2Negative electrode and voltage-stabilizing capacitor C_oIs connected to the first terminal of the transformer T₁Secondary side first winding N_s1End of synonym and transformer T₁Secondary side secondary winding N_s2Different name end and voltage-stabilizing capacitor C_oIs connected to the second terminal of the transformer T₁Secondary side secondary winding N_s2Dotted terminal of and diode D_o1The positive electrode of (1) is connected; voltage-stabilizing capacitor C_oAre used for connecting loads R in parallel_o。

The input electric energy is subjected to AC/DC conversion, then ripple waves are filtered out through LC filtering, the input direct current voltage is converted into alternating current voltage through a transformer T1, and stable direct current output voltage is provided for a load through full-wave rectification.

The transformer T1 is controlled to convert the input dc voltage into ac voltage by adjusting the turn-on and turn-off of the two switching tubes S1 and S2 after rectification, and provides a stable output voltage to the load through full-wave rectification. Moreover, the aim of correcting the power factor can be achieved by adjusting the on and off of the switch tube S1 and the switch tube S2, so that the efficiency is maximized. And the aim of reducing the ripple of the input current is achieved through the filtering of the inductor L1 and the capacitor Cs, so that the parameters and indexes of the novel circuit achieve better effects.

FIG. 3 is a schematic diagram of an integrated magnetic source device, an energy storage inductor L₁Inductor L2 and inductor L3 are coupled to transformer T₁To achieve magnetic integration.

Fig. 4 includes the conduction timing of the switch S1 and the switch S2, and the conduction timing of the switch S1 and the switch S2 is: switch tube S1 and switch tube S2 are turned on simultaneously, switch tube S1 is turned on and switch tube S2 is turned off, switch tube S1 and switch tube S2 are both turned on, switch tube S1 is turned off and switch tube S2 is turned on.

The working principle of the utility model is as follows:

firstly, alternating current passes through an AC/DC full-bridge rectification circuit, rectified current passes through an LC filter circuit, and then the switching tube S1 and the switching tube S2 are controlled to be switched on or off so that the inductive energy storage process and the energy supply process for a load are alternately carried out, and the function of power factor correction is achieved; the input dc voltage is then converted into an ac voltage by the transformer T1, and a stable voltage output is provided to the load by full-wave rectification. LED drive power supply have three kinds of mode, LED drive power supply is according to mode one, mode three, mode two and mode three order periodic work in proper order.

In the first working mode, when the switch tube S1 is turned on and the switch tube S2 is turned off, the energy of the energy storage inductor L1 and the DC voltage passing through the AC/DC are applied to the primary side primary winding N of the transformer T1_p1Two terminals, and a primary secondary winding N of the transformer T1_p2Since the current flows in the previous period, voltages of upper negative and lower positive are induced;

in the second working mode, when the switch tube S2 is turned on and the switch tube S1 is turned off, the voltage is applied to the primary secondary winding N of the transformer T1_p2Two-terminal, primary secondary winding N of transformer T1_p2Voltage V across_p2Is up positive and down negative, and is the same as the set positive direction, otherwise, the primary side first winding N of the transformer T1_p1Since the current is from bottom to top in the last cycle, a voltage of positive top and negative bottom is induced after the switching tube S1 is turned off;

in the third operating mode, when the switch tube S1 and the switch tube S2 are both in the conducting state, the secondary diode D of the transformer is connected to the secondary diode D₀₁And a diode D₀₂The secondary side of the transformer T1 is short-circuited by being conducted at the same time, the primary side voltage and the secondary side voltage of the transformer T1 are 0, the inductor L1 stores energy at the moment, and the primary side first winding N of the transformer T1 is connected with the primary side first winding N_p1Voltage Vp1 at two ends and primary secondary winding N of transformer T1_p2The voltage Vp2 across cancels out. At this time, the voltage-stabilizing capacitor C_OAnd the load is connected in parallel, so that the load has stable voltage output.

The L0 in the traditional circuit is used for filtering and rectifying, the circuit adopts a push-pull transformer, the voltage output after the rectification of a switch power supply of the push-pull transformer is basically direct current, no alternating current component exists, and the electric energy with very small voltage ripple and current ripple can be obtained without filtering by a filter inductor.

Analyzing the working mode:

FIG. 5 shows a first operating mode, in which the switch tube S is opened and closed₁Conducting and switching tube S₂The inductor L is switched off, the alternating current passes through the rectifier bridge, the LC filtering is carried out, and the ripple wave is filtered out₁The energy is released, and the AC component of the primary current of the transformer flows through the inductor L₂Inductor L₃And a capacitor C_sThe direct current component flows through the inductor L₁(ii) a Output voltage equal to V_s1Then passes through a rectifier diode D_O1And a voltage-stabilizing capacitor C_OTo guarantee the voltage across the load.

FIG. 6 shows the second operation mode, in which the switch tube S is turned on or off₁Switch off and switch tube S₂Conducting, passing the alternating current through a rectifier bridge, filtering by LC, filtering to remove ripple wave, and providing an inductor L₁The AC component of the primary current of the transformer flows through the inductor L in sequence to release energy₂Inductor L₃And a capacitor C_s(ii) a The DC component of the primary current of the transformer flows through the inductor L₁Output voltage equal to V_s2Then passes through a rectifier diode D_O2And a voltage-stabilizing capacitor C_OTo guarantee the voltage across the load.

FIG. 5 shows the third operating mode, in which the switch tube S is opened and closed₁And a switching tube S₂All are conducted, alternating current passes through a rectifier bridge and then is filtered by an LC (inductance-capacitance) filter to filter out ripples, and an inductor L₁In the energy storage, the AC component of the primary side current of the transformer flows through the inductor L in sequence₂Inductor L₃And a capacitor C_s(ii) a The DC component of the primary current of the transformer flows through the inductor L₁Output voltage equal to V_CoVoltage stabilizing capacitor C_OTo guarantee the voltage across the load.

The traditional circuit adopts two-stage conversion, the function of power factor correction is achieved through a Boost circuit, the change of DC/DC is realized through a transformer, stable direct current voltage is output to a load, the circuit can realize the function of power factor correction and combine PFC and DC/DC together, the switching tube S1 and the switching tube S2 are switched on and off, the LED driving power supply comprises three switching modes, the LED driving power supply has the functions of power factor correction and ripple reduction, and magnetic integration enables the circuit design to be simpler, the cost to be lower, the size to be smaller, the circuit has good practicability, and the circuit has flexibility compared with the traditional mode.

The LED driving power supply has two important indexes, namely power factor and efficiency, the design of the circuit realizes the correction of the power factor by controlling the on and off of two switching tubes, thereby realizing the maximization of the efficiency, realizing the aim of reducing the ripple wave of the input current by inductance and capacitance filtering, and ensuring that the parameters and indexes of the novel circuit achieve better effect.

The above contents are only for explaining the technical idea of the present invention, and the protection scope of the present invention cannot be limited thereby, and any modification made on the basis of the technical solution according to the technical idea of the present invention all fall within the protection scope of the claims of the present invention.

Claims

1. The novel magnetically integrated LED driving power supply with low input ripple current is characterized by comprising an AC/DC (alternating current/direct current) rectifying circuit, an LC (inductance-capacitance) filtering circuit and a transformer T which are sequentially connected₁Rectifier circuit and voltage stabilizing capacitor C_oSaid transformer T₁Primary side first winding N_p1Is connected with the drain electrode of the switch tube S1, and the transformer T₁Primary side secondary winding N_p2Is connected with the drain electrode of the switch tube S2, and the transformer T₁Primary side first winding N_p1End of same name and transformer T₁Primary side secondary winding N_p2The homonymous terminals of the two terminals are connected; the LC filter circuit comprises an energy storage inductor L₁Inductor L₂Inductor L₃And a capacitor Cs, the energy storage inductor L₁The inductor L2 and the inductor L3 are coupled to the transformer T₁In the magnetic core of (2).

2. The novel magnetically-integrated low-input-ripple-current LED driving power supply according to claim 1, wherein the inductor L is₂Inductor L₃Is connected with the capacitor Cs in series to form a series branch circuit, and the series branch circuit and the transformer T are connected₁Primary side secondary winding N_p2And a switching tube S2, the energy storage inductor L₁End of synonym and inductance L₂The synonym end of (2) is connected.

3. The novel magnetically integrated low input ripple current LED driver power supply of claim 1, wherein said transformer T is configured to provide a dc current to said LED driver power supply₁Is a push-pull transformer.

4. The novel magnetically-integrated low-input-ripple-current LED driving power supply according to claim 1, wherein the AC/DC rectification circuit is a full-bridge rectification circuit.

5. The novel magnetically-integrated low-input-ripple-current LED driving power supply according to claim 1, wherein the turn-on timings of the switch tube S1 and the switch tube S2 are as follows: switch tube S1 and switch tube S2 are turned on simultaneously, switch tube S1 is turned on and switch tube S2 is turned off, switch tube S1 and switch tube S2 are both turned on, switch tube S1 is turned off and switch tube S2 is turned on.

6. The novel magnetically-integrated low-input-ripple-current LED driving power supply according to claim 1, wherein the switch tube S1 and the switch tube S2 are both MOS tubes.