High-gain soft-switching Boost converter

文档序号：1877986 发布日期：2021-11-23 浏览：4次中文

阅读说明：本技术 一种高增益软开关Boost变换器 (High-gain soft-switching Boost converter ) 是由邾玢鑫蓝海支树播杨楠李振华王凯宏黄悦华于 2021-08-23 设计创作，主要内容包括：一种高增益软开关Boost变换器,该变换器包括主电路、辅助电路；所述主电路包括Boost变换器、至少一个外衣单元。所述Boost变换器包含主电感L1、功率开关管S1、二极管D1、电容C1。所述辅助电路包括零电流电感Lr、辅助电感Ls、零电压电容Cr、二极管D2、D3、D4。本发明变换器实现了功率开关管的零电压关断和零电流导通,消除了功率开关管S1上的开关损耗,可以提高变换器的效率。(A high-gain soft-switching Boost converter comprises a main circuit and an auxiliary circuit; the main circuit comprises a Boost converter and at least one coat unit. The Boost converter comprises a main inductor L1, a power switch tube S1, a diode D1 and a capacitor C1. The auxiliary circuit comprises a zero current inductor Lr, an auxiliary inductor Ls, a zero voltage capacitor Cr, diodes D2, D3 and D4. The converter realizes zero voltage turn-off and zero current conduction of the power switch tube, eliminates the switching loss on the power switch tube S1, and can improve the efficiency of the converter.)

1. A high gain soft switching Boost converter, the converter comprising: a main circuit and an auxiliary circuit;

the main circuit comprises a Boost converter and at least one coat unit;

the Boost converter comprises a main inductor L1, a power switch tube S1, a diode D1 and a capacitor C1;

one end of a main inductor L1 is connected with the anode of an input power supply, the other end of the main inductor L1 is respectively connected with the drain of a power switch tube S1 and the anode of a diode D1, the source of the power switch tube S1 is connected with the cathode of the input power supply, the cathode of a diode D1 is connected with one end of a capacitor C1, and the other end of the capacitor C1 is connected with the cathode of the input power supply;

said garment unit comprising a capacitor Cn1, a capacitor Cn2, an inductance Ln1, a diode Dn1, n being a natural number and n being equal to or greater than 1, the garment unit comprising five ports: port I, port II, port III, port IV and port V;

one end of a capacitor Cn1 is connected with a port I, the other end of the capacitor Cn1 is respectively connected with one end of an inductor Ln1 and the anode of a diode Dn1, the other end of the inductor Ln1 is the port II, the cathode of the diode Dn1 is connected with one end of a capacitor Cn2, and the other end of the capacitor Cn2 is connected with the port III; the anode of the diode Dn1 is a port (r), and the cathode of the diode Dn1 is a port (c);

the port I is connected to the anode of a diode D1 in the Boost converter, the port II is connected to the cathode of a diode D1 in the Boost converter, and the port III is connected to the cathode of an input power supply;

the auxiliary circuit comprises a zero current inductor Lr, an auxiliary inductor Ls, a zero voltage capacitor Cs, diodes D2, D3 and D4;

one end of a zero current inductor Lr is respectively connected with one end of a capacitor C11 in the garment unit when n is 1, the anode of a diode D1 in the Boost converter and the other end of a main inductor L1;

the other end of the zero current inductor Lr is connected with the drain electrode of a power switch tube S1 in the Boost converter;

the cathode of the diode D2 is respectively connected with the anode of the input power supply and one end of the inductor L1;

the anode of the diode D2 is respectively connected with one end of the zero-voltage capacitor Cs and the cathode of the diode D3;

the anode of the diode D3 is connected with one end of the auxiliary inductor Ls;

the other end of the auxiliary inductor Ls is connected with the negative electrode of the input power supply and the source electrode of the power switch tube S1 respectively;

the other end of the zero-voltage capacitor Cs is connected with the source electrode of the power switch tube S1, the other end of the inductor Lr and the anode of the diode D4 respectively;

the cathode of the diode D4 is connected to the cathode of the diode D1 and one end of the capacitor C1.

2. A high-gain soft-switching Boost converter according to claim 1, wherein:

of the n garment units, the garment unit,

the port (r) of the second garment unit is connected to the port (r) in the first garment unit,

the port of the second garment unit is connected to the port in the first garment unit,

the port of the second coat unit is connected to the negative pole of the input power supply;

the port (r) of the third garment unit is connected to the port (r) in the second garment unit,

the port of the third garment unit is connected to the port in the second garment unit,

the port of the third coat unit is connected to the negative pole of the input power supply;

.... and so on;

the port (r) of the nth garment unit is connected to the port (r) in the (n-1) th garment unit,

the port of the nth garment unit is connected to the port of the (n-1) th garment unit,

the port of the nth coat unit is connected to the negative electrode of the input power supply;

two ends of the capacitor Cn2 are respectively connected with two ends of the load RL.

3. A high-gain soft-switching Boost converter according to claim 1, wherein: the grid electrode of the power switch tube S1 is connected with the PWM controller.

4. A high-gain soft-switching Boost converter according to claim 1, wherein: when the power switch tube S1 is conducted, the power switch tube S1 is conducted under the condition of zero current due to the action of the zero current inductor Lr, and the conduction loss of the power switch tube S1 is eliminated;

when the power switch tube S1 is turned off, due to the effect of the zero-voltage capacitor Cs, the power switch tube S1 is turned off under the zero-voltage condition, and the turn-off loss of the power switch tube S1 is eliminated.

5. A high-gain soft-switching Boost converter according to claim 1, wherein: when the transducer comprises two garment units, the working process of the circuit is divided into 9 working modes:

the first mode is as follows:

at the beginning of the mode, the main switch S1 is conducted under the ZCS condition because the magnitude and direction of the current on the zero-current inductor Lr and the inductor L1 cannot be suddenly changed; in this mode, the diodes D1, D3, D11, D21 are turned on, the inductors L1, L11, L21 are discharged, the auxiliary inductor Ls is charged, the capacitors C11, C21, Cr are discharged, and the capacitors C1, C12, C22 are charged; the diode D3 is turned on, and resonance starts between the auxiliary inductor Ls and the zero-voltage capacitor Cs; therefore, the Cs voltage falls sinusoidally, and the Ls current rises sinusoidally; in the working process, the main inductor L1 is linearly reduced, the zero current inductor Lr is linearly increased, the current of the auxiliary inductor Ls is sinusoidally increased, and when the currents of the diodes D1, D11 and D21 are reduced to zero, the mode is ended;

mode two:

in this mode, the diodes D1, D11, and D21 are turned off, the inductor L1 in the main circuit starts to charge, and the current increases linearly; the capacitors C1, C12 and C22 start to discharge and are charged with the capacitors C2, C11 and C12; the inductance L11, Lr, L21 current increases linearly; the auxiliary inductor Ls and the zero-voltage capacitor Cs continue to resonate, when the voltage across the zero-voltage capacitor Cs in the auxiliary circuit reaches the negative input voltage-Vin, the diode D2 starts to conduct under ZVS condition, the Cr voltage is clamped at this level, and the mode ends;

mode three:

in this mode, since the inductor Ls resonates with the zero-voltage capacitor Cs, energy is stored when a current flows through the inductor Ls; when the voltage on the capacitor Cs reaches a negative input voltage-Vin, the inductor Ls can continue to flow current through the diode D2 to feed back energy to the input power supply; the working state of the components in the main circuit is the same as the previous mode; when the current of the inductor Ls is reduced to zero and the diode D2 is cut off, the mode ends;

and a fourth mode:

in this mode, the auxiliary circuit stops operating; the working state of the components in the main circuit is the same as the previous mode, and the load is continuously supplied with power by C22; when the power switch tube S1 is turned off, the mode ends;

a fifth mode:

in mode five, due to the existence of zero voltage Cs, the power switch tube S1 is turned off under ZVS; in this mode, the working state of the components in the main circuit is the same as that of the previous mode, and the load is continuously supplied with power by the C22; the inductor L1 current linearly discharges Cs, and when Vcs reaches zero, the inductor L1 current linearly charges Cs; when Vcs reaches Vc1-Vin, diode D4 begins to conduct under ZVS conditions, the Cr voltage is clamped at this level, and the mode ends;

a sixth mode:

when the diode D4 is turned on, mode six begins, the diode D4 starts to be turned on under ZVS condition, and the current of the inductor L1 passes through Lr, D4, C1, D4 and uin; inductor current of L11 flows through C11, Lr, D4; the inductor current of L21 is divided into two paths, firstly flows through C21, C11, Lr, D4 and C1, and then flows through D21, an output stage (C22// RL) and C12; c1, C12 and C22 are charged, C11 and C21 are charged, and the current of all inductors is reduced; this mode ends when the capacitance C21 current drops to zero;

a seventh mode:

when the current of the capacitor C21 is reduced to zero, a mode seven begins, in the mode, the current of the capacitor C21 is increased in a reverse direction, and the inductive current of L11 is divided into two paths and flows through C11, Lr and D4 firstly; then flows through C21, D21 and the output stage (C22// RL); the current state of the rest inductors is the same as the previous mode, C1, C21 and C22 are charged, C11 and C12 are discharged, and the current of all inductors is reduced; this mode ends when the capacitance C11 current drops to zero;

the mode is eight:

when the current of the capacitor C11 is reduced to zero, a mode eight begins, in the mode, the current of the capacitor C11 is increased in a reverse direction, the inductance current of L1 is divided into two paths, and the two paths firstly flow through Lr, D4 and C1; then flows through C11, C21 and the output stage (C22// RL); the inductor current of L11 flows through C21, D21, the output stage (C22// RL) and C1; the current states of the other inductors are the same as the previous mode, C1, C11, C21 and C22 are charged, C12 is discharged, and all inductor currents are reduced; when the inductor Lr current decreases to zero, the mode ends;

the mode is nine:

when the inductor Lr current decreases to zero, the mode nine begins, in which the capacitors C1, C12, and C22 begin to charge and the capacitors C11 and C21 begin to discharge; the current on inductor L1 begins to decrease linearly; this mode ends when the power switch S1 is conducting.

Technical Field

The invention relates to a direct current-direct current converter, in particular to a high-gain soft switching Boost converter.

Background

In the conventional switching power supply technology, a Boost coat circuit well realizes high voltage gain, but in a high-gain DC/DC converter, in order to reduce the cost of the converter and improve the power density of the converter, the working frequency of a switching tube of the converter needs to be improved. However, there are still difficulties in achieving high frequency operation of the converter. The main reason is that as the operating frequency of the converter is increased, the switching loss of the switching tube is correspondingly increased, which further reduces the operating efficiency of the converter and increases the heat productivity. In addition, the heat sink volume and weight also increase. The increase in switching frequency mainly causes the following two problems:

(1) the problem of switching losses: in the switching process of the power switch tube, the voltage and the current of the power switch tube are not zero, and an overlapping area appears, and the area is the switching loss of the power switch tube. The switching loss and the switching frequency have a linear relation, and the switching loss can be obviously increased after the switching frequency is increased.

(2) Emi (electromagnetic interference) electromagnetic interference effects: when the converter operates at high frequency, the voltage and current change faster, the waveform will overshoot significantly, the switching tubes will have to produce higher du/dt and di/dt, which will have an impact on the power supply itself and surrounding electronics, and switching noise, and EMI problems will become more severe after further increase of the switching frequency.

Aiming at the problems of the existing high-gain DC/DC converter, the soft switching technology is adopted, so that the switching loss can be reduced to zero theoretically, and meanwhile, the interference of EMI problems to electronic devices can be reduced.

Disclosure of Invention

The invention provides a high-gain soft switching Boost converter, which enables a power switching tube to realize zero voltage turn-off and zero current turn-on through an auxiliary circuit and reduces the switching loss on the power switching tube in the circuit.

The technical scheme adopted by the invention is as follows:

a high-gain soft-switched Boost converter, the converter comprising: a main circuit and an auxiliary circuit;