Zero-voltage turn-off zero-current turn-on high-gain Cuk converter

文档序号：1877984 发布日期：2021-11-23 浏览：4次中文

阅读说明：本技术 一种零电压关断零电流开通高增益Cuk变换器 (Zero-voltage turn-off zero-current turn-on high-gain Cuk converter ) 是由邾玢鑫蓝海赵宇辉支树播杨楠李振华王凯宏于 2021-08-23 设计创作，主要内容包括：一种零电压关断零电流开通高增益Cuk变换器,该变换器包括主电路、辅助电路；所述主电路包括Cuk变换器、至少一个外衣单元。Cuk变换器包含两个电感L1、L2,一个功率开关管S1,一个二极管D1和两个电容C1、C2。所述辅助电路包括零电流电感Lr、辅助电感Ls、零电压电容Cs、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,实现了软开关无损的目的,可以提高变换器效率。(A zero-voltage cut-off zero-current turn-on high-gain Cuk converter comprises a main circuit and an auxiliary circuit; the main circuit comprises a Cuk transducer, at least one garment unit. The Cuk converter comprises two inductors L1, L2, a power switch S1, a diode D1 and two capacitors C1, C2. The auxiliary circuit comprises a zero current inductor Lr, an auxiliary inductor Ls, a zero voltage capacitor Cs, 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, realizes the purpose of soft switching without loss, and can improve the efficiency of the converter.)

1. A zero-voltage cut-off zero-current turn-on high-gain Cuk converter is characterized by comprising a main circuit and an auxiliary circuit;

the main circuit comprises a Cuk transducer and at least one coat unit;

the Cuk converter comprises an inductor L1, a power switch tube S1, a capacitor C1, a diode D1, an inductor L2 and a capacitor C2;

one end of an inductor L1 is connected with the anode of an input power supply, the other end of the inductor L1 is respectively connected with the drain of a power switch tube S1 and one end of a capacitor C1, and the source of the power switch tube S1 is connected with the cathode of the input power supply; the other end of the inductor L2 is connected with one end of a capacitor C2; the other end of the capacitor C2 is respectively connected with the cathode of the diode D1, the drain of the power switch tube S1 and 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 the capacitor Cn1 is a port I, the other end of the capacitor Cn1 is respectively connected with the anode of the diode Dn1 and one end of the inductor Ln1, and the cathode of the diode Dn1 is the port II; the other end of the inductor Ln1 is connected with one end of a capacitor Cn2, and the other end of the capacitor Cn2 is a port c; the anode of the diode Dn1 is a port (r), and the other end of the inductor Ln1 is a port (c);

the port I is respectively connected to one end of an inductor L2 and the anode of a diode D1 in the Cuk converter, the port II is respectively connected to the other end of an inductor L2 and one end of a capacitor C2 in the Cuk 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 connected with the anode of a diode D4 and the other end of a capacitor C1 in the Cuk converter;

the other end of the zero-current inductor Lr is respectively connected with one end of a capacitor C11 in the first coat unit, one end of an inductor L2 in the Cuk converter and the anode of a diode D1;

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 auxiliary 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 cathode of the diode D4 is connected with the cathode of the input power supply;

the other end of the zero-voltage capacitor Cs is connected with the source electrode of the power switch tube S1, one end of the capacitor C1 and the other end of the main inductor L1 respectively.

2. The zero-voltage turn-off zero-current turn-on high-gain Cuk 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 of the first time 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 pole of the input power supply.

3. The zero-voltage turn-off zero-current turn-on high-gain Cuk converter according to claim 1, wherein: the grid electrode of the power switch tube S1 is connected with the controller.

4. The zero-voltage turn-off zero-current turn-on high-gain Cuk 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 zero-voltage turn-off zero-current turn-on high-gain Boost converter according to claim 1, 2, 3 or 4, wherein when two garment units are included, the operation of the circuit is divided into 10 operation 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 and D21 are turned on, the inductors L1, L11 and L21 are discharged, the auxiliary inductor Ls is charged, the capacitors C1, C11 and C21 are charged, and the capacitors Cs, C2, C12 and C22 are discharged; when the diode D3 is turned on, 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; when the zero current inductance Lr decreases linearly to zero, the mode ends;

mode two:

in this mode, the diodes D1, D11, and D21 are turned off, the inductor L1 and the zero-current inductor Lr in the main circuit start to charge, and the current linearly increases; the capacitors C1, C11 and C21 start to discharge, the capacitors C2, C12 and C22 are charged, and the currents of the inductors L11, Lr and L21 are increased 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 Cs voltage is clamped at this level, and the mode ends;

mode three:

in the third mode, because the inductor Ls is in resonance with the zero-voltage capacitor Cs, energy is stored when current flows through the inductor Ls; when the voltage on Cs reaches the negative input voltage-Vin, inductor Ls will freewheel through diode D2 to feed back energy to the input power; 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 current of the inductor L1 is discharged Cs linearly, and when VCS reaches zero, the current of the inductor L1 is charged Cs linearly; when VCs reaches Vc1-Vin, diode D4 begins to conduct under ZVS conditions, the Cs voltage is clamped at this level, and the mode ends;

a sixth mode:

when diode D21 turns on, mode six begins, diode D4 begins to turn on under ZVS condition, and the current of inductor L1 passes through C1, D4 and uin; the inductor current of L2 flows through Lr, D4 and C2; inductor current of L11 flows through C11, Lr, D4 and C12; the inductor current of L21 is divided into two paths, firstly flows through C21, C11, Lr, D4 and the output stage (C22// RL), and then flows through D21, C12 and the output stage (C22// RL); c1, C2, C12 and C22 are charged, C11 and C21 are discharged, and all inductor currents are reduced; this mode ends when the capacitance C21 current drops to zero;

a seventh mode:

when the capacitor C21 current decreases to zero, mode seven begins, in which the capacitor C21 current increases in reverse, and the inductor current of L11 flows through C21, D21; the inductor current of L21 flows through D21, C12 and the output stage (C22// RL); the current states of other inductors are the same as the previous mode, C1, C2, C12, C21 and C22 are charged, C11 is discharged, and the currents of all inductors are 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 L2 is divided into two paths, the two paths firstly flow through C11, C21, D21 and C12, and then flow through Lr, D4 and C2; the current states of other inductors are the same as the previous mode, C1, C1, C11, C12, C21 and C22 are charged, C12 is discharged, and all inductor currents are reduced; when the current of the inductor Lr is reduced to zero, the mode is ended;

the mode is nine:

when the inductor Lr current decreases to zero, a mode nine begins, in which the inductor Lr current increases in a reverse direction, and the inductor current of L2 flows through C11, C21, D21, and C12; the current states of other inductors are the same as the previous mode, C1, C1, C12, C21 and C22 are charged, C11 is discharged, and the currents of all other inductors are reduced; when the current of the inductor Lr is reversely increased to the input inductor current, D4 zero current is turned off, and the mode is ended;

and a modality of ten:

when the D4 is turned off with zero current and the D1 and D11 are turned on, the mode ten starts; the inductive current of L1 is divided into three paths; first through C1, D1 and uin, then through C1, C11, D11, C2 and uin, and finally through C1, C11, C21, D21, C12 and uin; inductor current of L2 flows through D1 and C2, inductor current of L11 flows through D11, C2 and C12, inductor current of L21 flows through D21, C12 and the output stage (C22// RL); c1, C11, C21 charge, C2, C12, C22 discharge, and all inductor currents drop.

Technical Field

The invention relates to a direct current-direct current converter, in particular to a zero-voltage turn-off zero-current turn-on high-gain Cuk converter.

Background

In the existing switching power supply technology, the Cuk 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 increased, but at present, the realization of high-frequency operation of the converter is still difficult. 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 zero-voltage off zero-current on high-gain Cuk converter, which enables the switching loss of a power switching tube to transfer energy back to a main circuit when the working condition of the power switching tube is changed 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 zero-voltage cut-off zero-current turn-on high-gain Cuk converter comprises a main circuit and an auxiliary circuit;