CN115566903B - A buck half-bridge soft-switching multi-channel current-sharing LED output converter - Google Patents

Abstract

The invention discloses a buck half-bridge soft switch multi-channel current equalizing LED output converter, which includes a DC power supply V _in , a switch tube S ₁ , a switch tube S ₂ , an energy storage inductance L _m , a diode D _i , and a capacitor C _k , load R _i , i∈{1~n}, k∈{1~(n‑1)}, i and k are the serial numbers of the output branches, and n is the total number of output branches. The present invention can realize n-channel constant current output by only using one inductor, has a very small number of inductors, and can effectively reduce the cost. Both switch tubes can realize zero-voltage turn-on, which greatly reduces switching loss.

Description

A buck half-bridge soft-switching multi-channel current-sharing LED output converter

technical field

The invention belongs to the technical field of power electronics, and in particular relates to a buck half-bridge soft switch multi-channel current-equalizing LED output converter, which is suitable for the fields of power electronics and the like.

Background technique

At present, in high-power occasions, LEDs are often connected in series and parallel. In order to improve its reliability and life, it is necessary to control the current balance between each string of LEDs. At present, the easiest way to achieve current sharing is to use the characteristics of capacitor charge balance for passive balancing. However, while realizing multi-channel current sharing, active switches and more inductive components are often required, and the switching loss of most active switches of converters is relatively large, resulting in low efficiency.

Contents of the invention

The object of the present invention is to provide a buck half-bridge soft-switching multi-channel current-sharing LED output converter for the above-mentioned problems in the prior art. The converter only uses two switch tubes, n diodes and one energy storage inductor to realize n constant current outputs. have a very small amount of inductance. At the same time, the two switch tubes both realize zero-voltage turn-on, which greatly reduces switching loss and improves efficiency.

Above-mentioned purpose of the present invention is achieved by the following technical means:

A buck half-bridge soft-switching multi-channel current-sharing LED output converter, including a DC power supply V _in , a switch tube S ₁ , a switch tube S ₂ , an energy storage inductor L _m , a diode D _i , a capacitor C _k , and a load R _i , i∈{1~n}, k∈{1~(n-1)}, i, k are output branch numbers, n is the total number of output branches,

When n is an even number:

The drain of the switch tube S1 is connected to the positive pole of _the DC power supply V _in , the drain of the switch tube S2 is connected to the source of the switch tube S1 _, the source of the switch tube _S2 is connected to the negative pole of the DC power supply V _in , and the DC power _supply V _in The negative pole of the energy storage inductor L _m is connected to the electrical ground GND, the _first connection end of the energy storage inductance L m is respectively connected to the source of the switch S1 and the drain of the switch S2 , and the second connection end of the energy storage inductance L _{m is} connected to the positive electrode of the capacitor C _p connected, p is an odd number, p=1, 3, ..., n-1,

When i=1, the cathode of the diode _D1 is connected to the cathode of the capacitor C1 , the anode _of the diode _D1 is connected to _the cathode of the load R1 , and the anode of the load R1 _is connected to the electrical ground GND,

When i=n, the anode of the diode D _n is connected to the negative pole of the capacitor C _n-1 , the cathode of the diode D _n is connected to the positive pole of the load R _n , and the negative pole of the load R _n is connected to the electrical ground GND,

When i≠1 and i≠n and i is an even number, the anode of the diode D _i is connected to the cathode of the capacitor C _i-1 , the cathode of the diode D _i is connected to the anode of the load R _i , and the cathode of the load R _i passes through the capacitor C _i is connected to the electrical ground GND,

When i≠1 and i≠n and i is an odd number, the cathode of diode D _i is connected to the cathode of capacitor C _i , the anode of diode D _i is connected to the cathode of load R _i , and the anode of load R _i passes through capacitor C _{i- 1} Connect to electrical ground GND.

When n is an odd number as described above:

The drain of the switch tube S1 is connected to the positive pole of _the DC power supply V _in , the drain of the switch tube S2 is connected to the source of the switch tube S1 _, the source of the switch tube _S2 is connected to the negative pole of the DC power supply V _in , and the DC power _supply V _in The negative pole of the energy storage inductor L _m is connected to the electrical ground GND, _the first connection end of the energy storage _inductor L m is respectively connected to the source of the switch tube S1 and the drain electrode of the switch tube S2 , and the second connection end of the energy storage inductor L _m is connected to the positive electrode of the capacitor C _q connected, q is an odd number, q=1, 3, ..., n-2,

When i=1, the cathode of the diode _D1 is connected to the cathode of the capacitor C1 , the anode _of the diode _D1 is connected to _the cathode of the load R1 , and the anode of the load R1 _is connected to the electrical ground GND,

When i=n, the cathode of the diode D _n is connected to the second connection end of the energy storage inductance L _m , the anode of the diode D _n is connected to the negative pole of the load R _n , and the positive pole of the load R _n is connected to the electrical ground through the capacitor C _n-1 GND,

When i≠1 and i≠n and i is an even number, the anode of the diode D _i is connected to the cathode of the capacitor C _i-1 , the cathode of the diode D _i is connected to the anode of the load R _i , and the cathode of the load R _i passes through the capacitor C _i is connected to the electrical ground GND,

When i≠1 and i≠n and i is an odd number, the cathode of diode D _i is connected to the cathode of capacitor C _i , the anode of diode D _i is connected to the cathode of load R _i , and the anode of load R _i passes through capacitor C _{i- 1} Connect to electrical ground GND.

As mentioned above, the load R _i is the light-emitting diode LED _i parallel filter capacitor C _oi , the anode of the light-emitting diode LED _i serves as the positive pole of the load R _i , and the cathode of the light-emitting diode LED _i serves as the negative pole of the load R _i .

As mentioned above, the converter is divided into six working modes:

Mode 1: switch tube S ₁ is turned on with zero voltage, switch tube S ₂ is turned off, diode D _r is subjected to forward voltage to conduct, diode D _v and diode D _n are subjected to reverse voltage to cut off, capacitors C ₁ ~ C _{(n- 2)} Charging, the capacitor C _(n-1) is clamped, the energy storage inductor L _m stores energy, r is an even number, r=2, 4,..., n-2, v is an odd number, v=1 ,3,...,n-1,

Mode 2: The switch tube S ₁ remains on, the switch tube S ₂ keeps off, the diode D _t is subjected to the forward voltage and is turned on, the diode D _v is subjected to the reverse voltage to cut off, and the capacitor C ₁ ~ C _(n-1) is charged, L _m stores energy, t is an even number, t=2, 4,..., n,

Mode 3: The switch tube S ₁ is disconnected, the switch tube S ₂ remains off, the diode D _t is subjected to the forward voltage to conduct, the diode D _v is subjected to the reverse voltage to cut off, and the capacitor C ₁ ~ C _(n-1) is charged, The energy storage inductance L _m releases energy, charges the junction capacitance of the switch tube _S1 , discharges the junction capacitance of the switch tube S2 , and provides zero-voltage turn _- on _conditions for the switch tube S2 ,

Mode 4: The switch tube S ₁ remains off, the switch tube S ₂ is turned on with zero voltage, the diode D _u is subjected to the forward voltage and conducts, the diode D _t and the diode D ₁ are subjected to the reverse voltage and cut off, and the capacitor C ₁ is clamped. Capacitor C ₂ ~ C _(n-1) discharges, energy storage inductor L _m stores energy, u is an odd number, u=3, 5,..., n-1,

Mode 5: The switch tube S ₁ is kept off, the switch tube S ₂ is kept on, the diode D _v is turned on under the forward voltage, the diode D _t is cut off under the reverse voltage, and the capacitors C ₁ ~ C _(n-1) are discharged, L _m stores energy,

Mode 6: The switch tube S ₁ remains off, the switch tube S ₂ is off, the diode D _v is turned on under the forward voltage, the diode D _t is cut off under the reverse voltage, and the capacitor C ₁ ~ C _(n-1) is discharged, L _m releases energy, discharges the junction capacitance of the switch tube S1 , charges the junction capacitance _of the switch tube S2 , and provides zero- _voltage turn _- on conditions for the switch tube S1 .

Compared with the prior art, the present invention has the following beneficial effects:

1. Only one inductor can be used to achieve n-channel constant current output, with a very small number of inductors, which can effectively reduce costs.

2. Both switch tubes can realize zero-voltage turn-on, which greatly reduces switching loss.

Description of drawings

Figure 1(a) is a schematic diagram of the circuit structure of a buck half-bridge soft-switching multi-channel current-sharing LED output converter with an even number of output branches;

Figure 1(b) is a schematic diagram of the circuit structure of a buck half-bridge soft-switching multi-channel current-sharing LED output converter with an odd number of output branches;

Fig. 2 is the schematic diagram of the circuit structure of the buck half-bridge soft switch multi-channel current sharing LED output converter with output branch n=4 in embodiment 3;

Fig. 3(a) is a schematic diagram of working mode 1 of the buck half-bridge soft-switching multi-channel current sharing LED output converter with output branch n=4 in embodiment 3;

Figure 3(b) is a schematic diagram of working mode 2 of the buck half-bridge soft-switching multi-channel current sharing LED output converter with output branch n=4 in embodiment 3;

Figure 3(c) is a schematic diagram of working mode 3 of the buck half-bridge soft switch multi-channel current sharing LED output converter with output branch n=4 in embodiment 3;

Figure 3(d) is a schematic diagram of working mode 4 of the buck half-bridge soft-switching multi-channel current sharing LED output converter with output branch n=4 in embodiment 3;

Figure 3(e) is a schematic diagram of working mode 5 of the buck half-bridge soft-switching multi-channel current sharing LED output converter with output branch n=4 in embodiment 3;

Figure 3(f) is a schematic diagram of working mode 6 of the buck half-bridge soft switch multi-channel current-sharing LED output converter with output branch n=4 in embodiment 3;

Figure 4(a) is a waveform diagram of the voltage of the switch tubes S ₁ and S ₂ and the driving signal magnified 100 times;

Figure 4(b) is a waveform diagram of the currents of the switch tubes S ₁ and S ₂ ;

Figure 4(c) is the output current waveform diagram of the output branch of the buck half-bridge soft-switching multi-channel current-sharing LED output converter.

Detailed ways

In order to facilitate those of ordinary skill in the art to understand and implement the present invention, the present invention will be described in further detail below in conjunction with the examples. It should be understood that the implementation examples described here are only used to illustrate and explain the present invention, and are not intended to limit the present invention.

Example 1

For the convenience of subsequent description and analysis, the definitions of parameters such as voltage and current of circuit components are as follows:

A buck half-bridge soft switch multi-channel current sharing LED output converter, including n output branches, n≥3. d ₁ and d ₂ are respectively defined as the duty cycle of the conduction time of the switch tubes S ₁ and S ₂ ; T _s is defined as the time of one switching cycle; f _s1 and f _s2 are defined as the switching frequency of the switch tubes S ₁ and S ₂ ; V _ds1 and V _ds2 are defined as the voltages at both ends of the switching tubes S ₁ and S ₂ , and the direction is from the drain to the source of the switching tubes S ₁ and S ₂ ; I _s1 and I _s2 are defined as the voltages at both ends of the switching tubes S ₁ and S ₂ The direction of the current is the same as V _ds1 and V _ds2 ; V _gs1 and V _gs2 are defined as the driving signals of the gates of the switching tubes S ₁ and S ₂ , and the direction is from the gate to the source of the switching tubes S ₁ and S ₂ ; V _LEDi (i=1, 2, ..., n) is defined as the voltage across the light-emitting diode LED _i (i = 1, 2, ..., n), and the direction is shown in Figure 1(a) and Figure 1(b) display and load R _i in the same direction; I _LEDi (i=1, 2, ..., n) is defined as the average current on the light-emitting diode LED _i (i = 1, 2, ..., n), and the direction is the same as V _LEDi (i=1, 2,..., n) in the same direction; I _Di (i=1, 2,..., n) is defined as diode D _i (i=1, 2,..., n) The average current on the diode D _i (i=1, 2, ..., n) in the direction from the anode to the cathode; V _Ck (k = 1, 2, ..., n-1) is defined as the capacitance C _k (k=1, 2, ..., n-1) the voltage at both ends, the direction is shown in Figure 1 (a) and Figure 1 (b); Q C _kch (k = 1, 2, ..., n -1) is defined as the amount of charge charged by the capacitor C _k (k=1, 2,..., n-1) in one switching cycle; Q C _kdis (k=1, 2,..., n-1) It is defined as the amount of charge discharged by the capacitor C _k (k=1, 2, ..., n-1) in one switching cycle; the input voltage is defined as the DC power supply voltage V _in , and the direction is shown in Figure 1 (a) and Figure 1 ( b) as shown.

A buck half-bridge soft-switching multi-channel current-sharing LED output converter, with a total of n output branches, n greater than or equal to 3, including DC power supply V _in , switching tube S ₁ , switching tube S ₂ , and energy storage inductor L _m , diode D _i (i=1, 2,..., n), capacitor C _k (k=1, 2,..., n-1), load R _i (i=1, 2,... , n), where the load R _i can be equivalent to a light-emitting diode LED _i (i=1, 2,..., n) connected in parallel with a filter capacitor C _oi (i=1, 2,..., n), which emits light The anode of the diode LED _i serves as the positive pole of the load R _i , and the cathode of the light emitting diode LED _i serves as the negative pole of the load R _i .

when n is even

The drain of the switch tube S1 is connected to the positive pole of _the DC power supply V _in . _The drain of the switching tube S2 is connected to the source of the switching tube S1 , _the source of the switching tube S2 is connected to the negative pole of the DC power supply V _in , and the negative pole of _the DC _power supply Vin is connected to the electrical ground GND. The first connection end of the energy storage inductance L _m is respectively connected to the source of the switch S1 and the drain of the switch S2 , and _the second _connection end of the energy storage inductance L _m is connected to the capacitor C _p (p is an odd number, p=1 , 3,..., n-1) are connected to the positive pole.

When i=1, the cathode of the diode _D1 is connected to the cathode of the capacitor C1 , the anode _of the diode _D1 is connected to _the cathode of the load R1 , and the anode of the load R1 _is connected to the electrical ground GND,

When i=n, the anode of the diode D _n is connected to the negative pole of the capacitor C _n-1 , the cathode of the diode D _n is connected to the positive pole of the load R _n , and the negative pole of the load R _n is connected to the electrical ground GND,

When i≠1 and i≠n and i is an even number, the anode of the diode D _i is connected to the cathode of the capacitor C _i-1 , the cathode of the diode D _i is connected to the anode of the load R _i , and the cathode of the load R _i passes through the capacitor C _i is connected to the electrical ground GND,

When i≠1 and i≠n and i is an odd number, the cathode of diode D _i is connected to the cathode of capacitor C _i , the anode of diode D _i is connected to the cathode of load R _i , and the anode of load R _i passes through capacitor C _{i- 1} Connect to electrical ground GND.

To simplify the analysis, assume:

(1) All switches, diodes, capacitors, and inductors are ideal devices.

(2) Capacitance values of capacitors C ₁ ~ C _(n-1) are all equal.

(3) The energy storage inductor L _m works in CCM (continuous inductor current) mode.

The converter can be divided into six working modes:

Mode 1: The switch tube S ₁ is turned on at zero voltage, the switch tube S ₂ is turned off, the diode D _r (r is an even number, r=2, 4, ..., n-2) is subjected to forward voltage conduction, and the diode D _v (v is an odd serial number, v=1, 3, ..., n-1) and diode D _n withstand reverse voltage cut-off, capacitor C ₁ ~ C _(n-2) charges, capacitor C _{(n-1 )} is clamped, the energy storage inductor L _m stores energy.

Mode 2: The switch tube S ₁ keeps on, the switch tube S ₂ keeps off, the diode D _t (t is an even number, t=2, 4, ..., n) is subjected to forward voltage conduction, and the diode D _v (v is an odd number, v=1, 3, ..., n-1) Under reverse voltage cut-off, capacitors C ₁ ~ C _(n-1) are charged, and L _m stores energy.

Mode 3: switch tubeS ₁disconnect, switch tubeS ₂kept disconnected, the diodeD. _t(t is an even number, t=2, 4, ..., n) withstand forward voltage conduction, the diodeD. _v(v is an odd serial number, v=1, 3, ..., n-1) withstand reverse voltage cut-off, capacitanceC ₁~ C _(n-1)Charging, energy storage inductanceL _mRelease energy, to the switch tube S₁Junction capacitance charging, switching tubeS ₂Junction capacitance discharge, for the switching tubeS ₂Provides a zero voltage turn-on condition.

Mode 4: The switch tube S ₁ remains off, the switch tube S ₂ is turned on with zero voltage, and the diode D _u (u is an odd number, u=3, 5, ..., n-1) is turned on with forward voltage, Diode D _t (t is an even number, t=2, 4, ..., n) and diode D ₁ are cut off with reverse voltage, capacitor C ₁ is clamped, capacitor C ₂ ~ C _(n-1) is discharged, The energy storage inductor L _m stores energy.

Mode 5: The switch tube S ₁ remains off, the switch tube S ₂ keeps on, the diode D _v (v is an odd number, v=1, 3, ..., n-1) is subjected to forward voltage conduction, the diode D _t (t is an even number, t=2, 4, ..., n) withstands the reverse voltage cut-off, capacitors C ₁ ~ C _(n-1) discharge, L _m stores energy.

Mode 6: switch tubeS ₁kept open, the switch tubeS ₂disconnected, diodeD. _v(v is an odd serial number, v=1, 3, ..., n-1) Under the forward voltage conduction, the diodeD. _t(t is an even number, t=2, 4, ..., n) withstand reverse voltage cut-off, capacitanceC ₁~ C _(n-1)discharge,L _mrelease energy to the switching tubeS ₁junction capacitance discharge, the switching tubeS ₂Junction capacitance charging, for the switch tubeS ₁Provides a zero voltage turn-on condition.

Example 2

A buck half-bridge soft-switching multi-channel current-sharing LED output converter, with a total of n output branches, n greater than or equal to 3, including DC power supply V _in , switching tube S ₁ , switching tube S ₂ , and energy storage inductor L _m , diode D _i (i=1, 2,..., n), capacitor C _k (k=1, 2,..., n-1), load R _i (i=1, 2,... , n), where the load R _i can be equivalent to a light-emitting diode LED _i (i=1, 2,..., n) connected in parallel with a filter capacitor C _oi (i=1, 2,..., n), which emits light The anode of the diode LED _i serves as the positive pole of the load R _i , and the cathode of the light emitting diode LED _i serves as the negative pole of the load R _i .

when n is odd

The drain of the switch tube S1 is connected to the positive pole of _the DC power supply V _in . _The drain of the switching tube S2 is connected to the source of the switching tube S1 , _the source of the switching tube S2 is connected to the negative pole of the DC power supply V _in , and the negative pole of _the DC _power supply Vin is connected to the electrical ground GND. The first connection end of the energy storage inductance L _m is respectively connected to the source of the switch S1 and the drain of the switch S2 , and _the second _connection end of the energy storage inductance L _m is connected to the capacitor C _q (q is an odd number, q=1 , 3,..., n-2) are connected to the positive pole.

When i=1, the cathode of the diode _D1 is connected to the cathode of the capacitor C1 , the anode _of the diode _D1 is connected to _the cathode of the load R1 , and the anode of the load R1 _is connected to the electrical ground GND,

When i=n, the cathode of the diode D _n is connected to the second connection end of the energy storage inductance L _m , the anode of the diode D _n is connected to the negative pole of the load R _n , and the positive pole of the load R _n is connected to the electrical ground through the capacitor C _n-1 GND,

When i≠1 and i≠n and i is an even number, the anode of the diode D _i is connected to the cathode of the capacitor C _i-1 , the cathode of the diode D _i is connected to the anode of the load R _i , and the cathode of the load R _i passes through the capacitor C _i is connected to the electrical ground GND,

When i≠1 and i≠n and i is an odd number, the cathode of diode D _i is connected to the cathode of capacitor C _i , the anode of diode D _i is connected to the cathode of load R _i , and the anode of load R _i passes through capacitor C _{i- 1} Connect to electrical ground GND.

The working mode of the converter is similar to that of Embodiment 1, and will not be repeated here.

Example 3

A buck half-bridge soft-switching multi-channel current-sharing LED output converter, n is an even number of 4, and the others are the same as in Embodiment 1, as shown in FIG. 2 .

To simplify the analysis, assume:

(1) All switches, diodes, capacitors, and inductors are ideal devices.

(2) The capacitance values of the capacitors C _k (k=1, 2, . . . , n−1) are all equal.

(3) The energy storage inductor L _m works in CCM (continuous inductor current) mode.

As shown in Figure 2, the converter can be divided into six working modes.

Mode 1: switch tube S ₁ is turned on with zero voltage, switch tube S ₂ is turned off, diode D ₂ is turned on with forward voltage, diodes D ₁ , D ₃ and D ₄ are cut off with reverse voltage, capacitors C ₁ and C ₂ Charging, the capacitor C ₃ is clamped, and the energy storage inductor L _m stores energy.

Mode 2: switch tube S ₁ keeps on, switch tube S ₂ keeps off, diodes D ₂ and D ₄ are turned on with forward voltage, diodes D ₁ and D ₃ are cut off with reverse voltage, capacitors C ₁ and C ₂ and C ₃ charges, L _m stores energy.

Mode 3: switch tube S ₁ is disconnected, switch tube S ₂ remains off, diodes D ₂ and D ₄ are turned on under forward voltage, diodes D ₁ and D ₃ are cut off under reverse voltage, capacitors C ₁ and C ₂ and C ₃ charge, the energy storage inductor L _m releases energy, charges the junction capacitance of the switch tube S ₁ , discharges the junction capacitance of the switch tube S ₂ , and provides zero-voltage turn-on conditions for the switch tube S ₂ .

Mode 4: The switch tube S ₁ is kept off, the switch tube S ₂ is turned on with zero voltage, the diode D ₃ is turned on under the forward voltage, the diodes D ₁ , D ₂ and D ₄ are turned off under the reverse voltage, and the capacitor C ₁ is clamped Bit, capacitors C ₂ and C ₃ discharge, energy storage inductor L _m stores energy.

Mode 5: switch tube S ₁ remains off, switch tube S ₂ keeps on, diodes D ₁ and D ₃ are turned on with forward voltage, diodes D ₂ and D ₄ are cut off with reverse voltage, capacitors C ₁ and C ₂ and C ₃ discharge, L _m stores energy.

Mode 6: The switch tube S ₁ remains disconnected, the switch tube S ₂ is disconnected, the diodes D ₁ and D ₃ are turned on under the forward voltage, the diodes D ₂ and D ₄ are turned off under the reverse voltage, and the capacitors C ₁ and C ₂ and C ₃ discharge, L _m releases energy, discharges the junction capacitance of the switch tube S ₁ , charges the junction capacitance of the switch tube S ₂ , and provides zero-voltage turn-on conditions for the switch tube S ₁ .

From the above modal capacitor charging and discharging process, we can get:

（1）

(1)

The charge balance formula combined with balancing capacitors:

（2）

(2)

Combining formulas (1) and (2), we can get:

（3）

(3)

Therefore, using the charge balancing mechanism of the capacitor, the current of each output branch of the converter can be automatically balanced.

The converter of this embodiment shown in Figure 3(a)~(f) is simulated on the Psim platform, as shown in Figure 4(a)~(c) is the buck half-bridge soft switch four-way current sharing LED Simulate the main waveform. The main parameters of the simulation are set as follows: DC power supply voltage V _in =200V, switching frequency f _s1 = f _s2 =67kHz, duty cycle d ₁ =0.4, d ₂ =0.5, energy storage inductance L _m =25uH, capacitor C ₁ = C ₂ = C ₃ =2uF, filter capacitors C _o1 , C _o2 , C _o3 , C _o4 =10uF, and the equivalent impedances of loads R ₁ , R ₂ , R ₃ , and R ₄ are 100Ω, 80Ω, 60Ω, and 40Ω, respectively.

Among them, Figure 4(a) is the waveform diagram of the voltage of the switch tubes S ₁ and S ₂ and the driving signal magnified 100 times, Figure 4(b) is the waveform diagram of the current of the switch tubes S ₁ and S ₂ , and Figure 4(c) is the waveform diagram of the branch current.

Based on the above analysis and simulation, the buck half-bridge soft-switching multi-channel current-sharing LED output converter has the following advantages:

1. Only one inductor can be used to achieve n-channel constant current output, with a very small number of inductors, which can effectively reduce costs.

2. Both active switching tubes can realize zero-voltage turn-on, which greatly reduces switching loss.

So this converter is very suitable for LED drive.

The above disclosures are only preferred embodiments of the present invention, but the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention shall be covered by this disclosure. within the scope of protection of the invention. Therefore, the protection scope of the present invention should be within the protection scope of the claims and some improvements made without departing from the principle of the present invention should all fall within the protection scope of the present invention.

Claims (1)

1. A buck half-bridge soft-switching multi-channel current-sharing LED output converter, including a DC power supply V _in , characterized in that it also includes a switch tube S ₁ , a switch tube S ₂ , an energy storage inductor L _m , a diode D _i , Capacitance C _k , load R _i , i∈{1~n}, k∈{1~(n-1) }, i, k are output branch numbers, n is the total number of output branches, When n is an even number: The drain of the switch tube S1 is connected to the positive pole of _the DC power supply V _in , the drain of the switch tube S2 is connected to the source of the switch tube S1 _, the source of the switch tube _S2 is connected to the negative pole of the DC power supply V _in , and the DC power _supply V _in The negative pole of the energy storage inductor L _m is connected to the electrical ground GND, the _first connection end of the energy storage inductance L m is respectively connected to the source of the switch S1 and the drain of the switch S2 , and the second connection end of the energy storage inductance L _{m is} connected to the positive electrode of the capacitor C _p connected, p is an odd number, p=1, 3, ..., n-1, When i=1, the cathode of the diode _D1 is connected to the cathode of the capacitor C1 , the anode _of the diode _D1 is connected to _the cathode of the load R1 , and the anode of the load R1 _is connected to the electrical ground GND, When i=n, the anode of the diode D _n is connected to the negative pole of the capacitor C _n-1 , the cathode of the diode D _n is connected to the positive pole of the load R _n , and the negative pole of the load R _n is connected to the electrical ground GND, When i≠1 and i≠n and i is an even number, the anode of the diode D _i is connected to the cathode of the capacitor C _i-1 , the cathode of the diode D _i is connected to the anode of the load R _i , and the cathode of the load R _i passes through the capacitor C _i is connected to the electrical ground GND, When i≠1 and i≠n and i is an odd number, the cathode of diode D _i is connected to the cathode of capacitor C _i , the anode of diode D _i is connected to the cathode of load R _i , and the anode of load R _i passes through capacitor C _{i- 1} Connect to the electrical ground GND, When the n is an odd number: The drain of the switch tube S1 is connected to the positive pole of _the DC power supply V _in , the drain of the switch tube S2 is connected to the source of the switch tube S1 _, the source of the switch tube _S2 is connected to the negative pole of the DC power supply V _in , and the DC power _supply V _in The negative pole of the energy storage inductor L _m is connected to the electrical ground GND, _the first connection end of the energy storage _inductor L m is respectively connected to the source of the switch tube S1 and the drain electrode of the switch tube S2 , and the second connection end of the energy storage inductor L _m is connected to the positive electrode of the capacitor C _q connected, q is an odd number, q=1, 3, ..., n-2, When i=1, the cathode of the diode _D1 is connected to the cathode of the capacitor C1 , the anode _of the diode _D1 is connected to _the cathode of the load R1 , and the anode of the load R1 _is connected to the electrical ground GND, When i=n, the cathode of the diode D _n is connected to the second connection end of the energy storage inductance L _m , the anode of the diode D _n is connected to the negative pole of the load R _n , and the positive pole of the load R _n is connected to the electrical ground through the capacitor C _n-1 GND, When i≠1 and i≠n and i is an even number, the anode of the diode D _i is connected to the cathode of the capacitor C _i-1 , the cathode of the diode D _i is connected to the anode of the load R _i , and the cathode of the load R _i passes through the capacitor C _i is connected to the electrical ground GND, When i≠1 and i≠n and i is an odd number, the cathode of diode D _i is connected to the cathode of capacitor C _i , the anode of diode D _i is connected to the cathode of load R _i , and the anode of load R _i passes through capacitor C _{i- 1} Connect to the electrical ground GND, The load R _i is a light-emitting diode LED _i parallel filter capacitor C _oi , the anode of the light-emitting diode LED _i serves as the positive pole of the load R _i , and the cathode of the light-emitting diode LED _i serves as the negative pole of the load R _i , The converter is divided into six working modes: Mode 1: switch tube S ₁ is turned on with zero voltage, switch tube S ₂ is turned off, diode D _r is subjected to forward voltage to conduct, diode D _v and diode D _n are subjected to reverse voltage to cut off, capacitors C ₁ ~ C _{(n- 2)} Charging, the capacitor C _(n-1) is clamped, the energy storage inductor L _m stores energy, r is an even number, r=2, 4,..., n-2, v is an odd number, v=1 ,3,...,n-1, Mode 2: The switch tube S ₁ remains on, the switch tube S ₂ keeps off, the diode D _t is subjected to the forward voltage and is turned on, the diode D _v is subjected to the reverse voltage to cut off, and the capacitor C ₁ ~ C _(n-1) is charged, L _m stores energy, t is an even number, t=2, 4,..., n, Mode 3: The switch tube S ₁ is disconnected, the switch tube S ₂ remains off, the diode D _t is subjected to the forward voltage to conduct, the diode D _v is subjected to the reverse voltage to cut off, and the capacitor C ₁ ~ C _(n-1) is charged, The energy storage inductance L _m releases energy, charges the junction capacitance of the switch tube _S1 , discharges the junction capacitance of the switch tube S2 , and provides zero-voltage turn _- on _conditions for the switch tube S2 , Mode 4: The switch tube S ₁ remains off, the switch tube S ₂ is turned on with zero voltage, the diode D _u is subjected to the forward voltage and conducts, the diode D _t and the diode D ₁ are subjected to the reverse voltage and cut off, and the capacitor C ₁ is clamped. Capacitor C ₂ ~ C _(n-1) discharges, energy storage inductor L _m stores energy, u is an odd number, u=3, 5,..., n-1, Mode 5: The switch tube S ₁ is kept off, the switch tube S ₂ is kept on, the diode D _v is turned on under the forward voltage, the diode D _t is cut off under the reverse voltage, and the capacitors C ₁ ~ C _(n-1) are discharged, L _m stores energy, Mode 6: The switch tube S ₁ remains off, the switch tube S ₂ is off, the diode D _v is turned on under the forward voltage, the diode D _t is cut off under the reverse voltage, and the capacitor C ₁ ~ C _(n-1) is discharged, L _m releases energy, discharges the junction capacitance of the switch tube S1 , charges the junction capacitance _of the switch tube S2 , and provides zero- _voltage turn _- on conditions for the switch tube S1 .

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