CN106787706B - Coupling inductor hybrid lifting converter - Google Patents

Abstract

The invention provides a coupled-inductance hybrid boost converter, which is a novel topology structure of a boost converter fused with coupled inductance and multiple bootstrap circuits. In the present invention, the boosting capability of the converter is greatly improved by the repeated use of the secondary winding of the coupled inductor and the fusion of the multiple bootstrap circuits; One of the capacitors is a bootstrap capacitor, no additional capacitor is added, and the voltage of the second bootstrap capacitor is increased, so the cost does not increase, the boosting capability of the converter is improved, and the voltage stress of the switch tube is reduced. The last three freewheeling diodes realize zero-current turn-on, and the voltage stress of the output diode is fully reduced. It can be used in new energy system occasions.

Description

Coupled Inductor Hybrid Boost Converter

technical field

The present invention relates to a coupled-inductance hybrid boost converter. It is a step-up DC converter with high gain ratio.

Background technique

With the increasingly serious energy shortage and environmental pollution, the demand for renewable energy has become increasingly prominent, and more and more people in the world are looking forward to the use and development of renewable energy in daily life. Photovoltaic power generation systems, fuel cell systems, etc. have been widely used in today's production activities. However, due to the influence of parasitic parameters of conventional BOOST converters, its duty cycle cannot be too high, so the voltage of BOOST converters cannot be too high. The gain capability is low, the voltage stress of the switching tube is large, and the power loss is serious. Therefore, it is impossible for the BOOST converter to provide a high enough voltage gain ratio to increase the voltage to meet the needs of grid connection under the condition of high efficiency. For this reason, cascaded BOOST converters have appeared one after another, but when a higher boost ratio is achieved, the number of devices generated by the cascade increases, the problem of low efficiency is prominent, and the circuit becomes complicated. The emergence of coupled inductor technology has improved the ability of the converter to increase the gain, but it is also very serious to greatly reduce the efficiency of the converter due to voltage spikes caused by leakage inductance. Therefore, research on new high-gain converters has urgent practical needs and important theoretical significance.

SUMMARY OF THE INVENTION

Purpose of the invention: The present invention proposes a coupled-inductance hybrid boost converter that integrates coupled-inductance technology and bootstrap technology, which solves the problems of weak boosting capability and low efficiency of traditional converters, and can not only meet the needs of traditional converters On occasion, it is more competent for renewable energy power supply system.

Technical solutions:

A coupled-inductor hybrid boost converter, including a hybrid coupled-inductor network, a passive lossless clamp circuit, a filter capacitor C _o , a rectifier diode D _o and a resistive load R;

The hybrid coupled inductor network includes an input power supply V _in , a first bootstrap circuit and a second bootstrap circuit; the first bootstrap circuit includes a coupled inductor primary winding _LP , a coupled inductor secondary winding _LS , and a second bootstrap circuit. a rectifier diode D ₁ and a first boost capacitor C ₁ ; the second bootstrap circuit includes a coupled inductor secondary winding L _S , a third rectifier diode D ₃ , a switch S, a first boost capacitor C ₁ , a third two boosting capacitors C ₂ , and a third boosting capacitor C ₃ ;

The first boost capacitor C ₁ , the third boost capacitor C ₃ and the second rectifier diode D ₂ form a passive lossless clamping circuit;

The anode of the input power supply V _in is connected to the first end of the primary winding LP of the coupled inductor and the anode of the first rectifier diode D 1 at the same time, and the second end of the primary winding _LP is connected to the drain of the switch _S and the first end of the first rectifier diode D ₁ . The negative pole of a boosting capacitor _C1 is connected at the same time, and the first end of the secondary winding L _S of the coupled inductor is connected to the positive pole of the first boosting capacitor _C1 and the anode of the _second rectifier clamping diode D2 at the same time, and the coupled inductor pair The second end of the side winding _LS is connected to the cathode of the _first rectifier diode D1 and the cathode of the _second boost capacitor C2 at the same time; the anode of the third rectifier diode _D3 is connected to the cathode of the _second rectifier diode D2 and the third The positive pole of the boosting capacitor C3 is connected at the same time, the cathode of the _third rectifying diode _D3 is connected with the positive pole of the _{second boosting} capacitor C2 and the anode of the output diode Do at the same time, and the negative pole of the _third boosting capacitor C3 is connected with the filter capacitor The negative pole of C _o and the negative pole of the resistance load R are connected at the same time, and the cathode of the output diode _{Do is connected with the positive pole of the filter capacitor C o and} the positive pole of the resistance load R at the same time. The positive and negative poles of the capacitor are in the direction of the labels in Figure 1, and the positive and negative poles of the diode are in the direction of diode voltage stress.

The switch tube S is a MOS tube or an IGBT.

The coupled-inductance hybrid boost converter operates in a working mode.

Beneficial effects: the secondary winding LS of the coupled inductor in the coupled inductor hybrid boost converter of the present invention is used in both bootstrap circuits, and in addition, the second boost capacitor _{C 2} and the third boost capacitor C 2 and the third boost capacitor The first boost capacitor C ₁ in the first bootstrap circuit is used for charging C ₃ , so the voltage gain of the coupled-inductor hybrid boost converter can be improved as much as possible under the condition of as few devices as possible. At the same time, the passive lossless clamp circuit composed of the first boost capacitor C ₁ , the third boost capacitor C ₃ and the second rectifier diode D ₂ , namely the clamp diode, effectively reduces the voltage stress of the switch tube and effectively absorbs The energy of the leakage inductance of the coupling inductor is reduced, and the voltage of the _third boosting capacitor C3 is increased due to the existence of the first boosting capacitor _C1 , so that the voltage stress of the output diode _Do can be effectively reduced.

It can be found from Figure 16 that there is no excessive voltage spike in the voltage waveform across the switching tube of the converter, and it can be found from Figure 17 that the voltage stress of the output diode is very low.

Description of drawings

FIG. 1 is a schematic diagram of the coupled-inductor hybrid boost converter according to the first embodiment.

Figure 2 is an equivalent circuit diagram of a coupled-inductor hybrid boost converter.

为耦合电感副边绕组的电流，i_Do为输出二极管D_o的电流，i_DS为流过开关管S的电流，i_in为输入电源的电流，i_D1为第一整流二极管D₁的电流，i_D2为第二整流二极管D₂的电流，i_D3为第三整流二极管D₃的电流，i_C1为第一升压电容C₁的电流，i_C2为第二升压电容C₂的电流，i_C3为第三升压电容C₃的电流，

为耦合电感原边绕组的电压，

为耦合电感副边绕组的电压。Figure 3 is the modal diagram of the coupled inductor hybrid boost converter. In Figure 3, i _LM is the excitation current of the primary winding of the coupled inductor, i _LK is the leakage inductance current of the primary winding of the coupled inductor,

is the current of the secondary winding of the coupled inductor, i _Do is the current of the output diode D _o , i _DS is the current flowing through the switch S, i _in is the current of the input power supply, i _D1 is the current of the first rectifier diode D ₁ , i _D2 is the current of the second rectifier diode D ₂ , i _D3 is the current of the third rectifier diode D ₃ , i _C1 is the current of the first boost capacitor C ₁ , i _C2 is the current of the second boost capacitor C ₂ , i _C3 is the current of the _third boost capacitor C3,

is the voltage of the primary winding of the coupled inductor,

is the voltage on the secondary winding of the coupled inductor.

Figure 4 is an equivalent diagram of the first switching mode of the coupled-inductor hybrid boost converter.

Figure 5 is an equivalent diagram of the second switching mode of the coupled-inductor hybrid boost converter.

Figure 6 is an equivalent diagram of the third switching mode of the coupled-inductor hybrid boost converter.

Figure 7 is an equivalent diagram of the fourth switching mode of the coupled-inductor hybrid boost converter.

Figure 8 is an equivalent diagram of the fifth switching mode of the coupled-inductor hybrid boost converter.

Figure 9 is an equivalent diagram of the sixth switching mode of the coupled-inductor hybrid boost converter.

Figure 10 is an equivalent diagram of the seventh switching mode of the coupled-inductor hybrid boost converter.

Figure 11 is an equivalent diagram of the eighth switching mode of the coupled-inductor hybrid boost converter.

Figure 12 shows the input voltage V _in = 40V, the output voltage V _o =380V, the ordinate of the voltage difference V _GS between the drain and the source of the switch tube is 20 volts/cell, and the ordinate of the current i _D3 of the _third rectifier diode D3 The coordinate is 2.5 A/cell, the _ordinate of the current i _Do of the output diode Do is 2 A/cell, and the unit is the experimental waveform of 10 ms/cell.

Figure 13 shows the input voltage V _in = 40V, the output voltage V _o =380V, the ordinate of the voltage difference V _GS between the drain and source ends of the switch tube is 20V/cell, and the vertical axis of the current i _S at both ends of the gate source of the switch tube The coordinates are 20 A/cell, the ordinate of the current i _C3 of capacitor C3 is ₁₀ A/cell, and the unit is the experimental waveform of 10 ms/cell.

Figure 14 shows the input voltage V _in =40V, the output voltage V _o =380V, the ordinate of the voltage difference V _GS between the drain and source of the switch tube is 20V/cell, the current i _C2 of the second boost capacitor C ₂ is The ordinate is 10 A/cell, the ordinate of the current i _C1 of the first boost capacitor _C1 is 20 A/cell, and the unit is the experimental waveform of 10 ms/cell.

Figure 15 shows the input voltage V _in =40V, the output voltage V _o =380V, the ordinate of the voltage difference V _GS between the drain and source of the switch tube is 20V/cell, and the ordinate of the current i _D1 of the _first rectifier diode D1 The coordinates are 5 A/cell, the ordinate of the current i _D2 of the _second rectifier diode D2 is 30 A/cell, and the unit is the experimental waveform of 10 ms/cell.

Figure 16 shows the input voltage V _in = 40V, the output voltage V _o = 380V, the ordinate of the voltage difference V _GS between the drain and source ends of the switch is 20V/cell, and the vertical axis of the voltage V _DS across the gate and source of the switch The coordinate is 50 volts/cell, the ordinate of the current i _in of the input power supply is 30 A/cell, the ordinate of the voltage V _in of the input power supply is 50 volts/cell, and the unit is 10 ms/cell Experimental waveform .

Figure 17 shows the input voltage V _in =40V, the output voltage V _o =380V, the ordinate of the voltage difference V _GS between the drain and source ends of the switch tube is 20V/cell, and the ordinate of the voltage V _Do of the output diode D _o is Experimental waveform at 50 volts/cell in units of 10 ms/cell.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings.

Embodiment 1: Referring to FIG. 1 to specifically describe the implementation of this embodiment, the coupled-inductor hybrid boost converter described in this embodiment includes two bootstrap circuits, a passive lossless clamping circuit, a switch, a Filter capacitor C _o , a rectifier output diode D _o and a resistive load R,

One of the two bootstrap circuits includes a coupled inductor primary _LP , a coupled inductor secondary winding LS , a first rectifier diode D ₁ and a first boost capacitor _{C 1} , and the other bootstrap circuit includes a coupled inductor. The secondary winding L _S of the inductor, the third rectifier diode D ₃ , the switch S, the first boost capacitor C ₁ , the second boost capacitor C ₂ , and the third boost capacitor C ₃ ,

The passive lossless clamp circuit includes a first boost capacitor C ₁ , a third boost capacitor C ₃ and a second rectifier diode D ₂ ,

The anode of the input power supply V _in is connected to the first end of the primary winding LP of the coupled inductor and the anode of the first rectifier diode D 1 at the same time, and the second end of the primary winding _LP is connected to the drain of the switch _S and the first end of the first rectifier diode D ₁ . The negative pole of a boosting capacitor _C1 is connected, and the first end of the secondary winding L _S of the coupled inductor is connected to the positive pole of the first boosting capacitor _C1 and the anode of the _second rectifier diode D2 at the same time, and the secondary winding L of the coupled inductor is connected simultaneously. The second end of _S is connected to the cathode of the _first rectifier diode D1 and the cathode of the _second boost capacitor C2 at the same time; the anode of the third rectifier diode _D3 is connected to the cathode of the _second rectifier diode D2 and the _third capacitor C3 The anodes of the rectifier diodes D3 are connected simultaneously, the cathodes of the third rectifier diodes _D3 are connected to the anodes of the _second boost capacitor C2 and the anodes of the output diodes _D0 are simultaneously connected.

Embodiment 2: This embodiment further describes the coupled-inductance hybrid boost converter described in Embodiment 1. In this embodiment, the switch S is a MOS transistor or an IGBT.

Embodiment 3: This embodiment is described in detail with reference to FIGS. 2 to 11 . This embodiment further describes the coupled-inductance hybrid boost converter described in Embodiment 1. In this embodiment, the operation of the converter is Run in working mode.

The working principle and working process of the present invention are as follows:

原边理想变压器N_P、副边理想变压器N_S、副边漏电感

等效电路图如图2。The equivalent circuit of the coupled inductance of the coupled inductance hybrid boost converter of the present invention is the excitation inductance L _M , the leakage inductance

Primary ideal transformer _NP , secondary ideal transformer N _S , secondary leakage inductance

The equivalent circuit diagram is shown in Figure 2.

输出二极管D_o的电流为i_Do，流过开关管S的电流为i_DS，输入电源的电流为i_in，第一整流二极管D₁的电流为i_D1，第二整流二极管D₂的电流为i_D2，第三整流二极管D₃的电流为i_D3，第一升压电容C₁的电流为i_C1，第二升压电容C₂的电流为i_C2，第三升压电容C₃的电流为i_C3，耦合电感原边绕组的电压为耦合电感副边绕组的电压为

波形如图3所示，其工作过程分为8个开关模态，分别为第一种开关模态至第八种开关模态，电阻R为负载，具体描述如下：The excitation current of the primary winding of the coupled inductance of the coupled inductance hybrid boost converter of the present invention is i _LM , the leakage inductance current of the primary winding of the coupled inductance is i _LK , and the current of the secondary winding of the coupled inductance is

The current of the output diode D _o is i _Do , the current flowing through the switch S is i _DS , the current of the input power supply is i _in , the current of the first rectifier diode D ₁ is i _D1 , and the current of the second rectifier diode D ₂ is i _D2 , the current of the third rectifier diode D ₃ is i _D3 , the current of the first boost capacitor C ₁ is i _C1 , the current of the second boost capacitor C ₂ is i _C2 , and the current of the third boost capacitor C ₃ is i _C3 , the voltage on the primary winding of the coupled inductor is The voltage on the secondary winding of the coupled inductor is

The waveform is shown in Figure 3. Its working process is divided into 8 switching modes, which are the first switching mode to the eighth switching mode, and the resistance R is the load. The specific description is as follows:

The first switching mode corresponds to [t ₀ , t ₁ ] in Figure 3: the equivalent circuit is shown in Figure 4, the switch _S is turned on at time t ₀ , the primary winding LP of the coupled inductor is charged, and the secondary winding of the coupled inductor is charged. L ₂ freewheels together with the first boost capacitor C ₁ and the second boost capacitor C ₂ through the output diode _{Do, and the output capacitor C o supplies} power to the load R.

The second switching mode corresponds to [t ₁ , t ₂ ] in Fig. 3: the equivalent circuit is shown in Fig. 5. At time t ₁ , the output diode D ₀ is turned off, the third rectifier diode D ₃ is turned on, and the coupled inductor is The side winding LP continues to charge, the coupled inductor secondary winding _{L 2} stores energy, the third boost capacitor C ₃ discharges, the first boost capacitor C ₁ and the third boost capacitor C ₂ are charged, and the output capacitor C _{o supplies} the load R powered by.

The third switching mode corresponds to [t ₂ , t ₃ ] in FIG. 3 : the equivalent circuit is shown in FIG. 6 , at time t ₂ the first rectifier diode D ₁ is turned on, and the primary winding LP of the coupled _inductor continues to charge, The coupled inductor secondary winding L ₂ continues to store energy, the third boost capacitor C ₃ discharges, the first boost capacitor C ₁ and the second boost capacitor C ₂ continue to charge, and the output capacitor C _o supplies power to the load R.

The fourth switching mode, corresponding to [t ₃ , t ₄ ] in Figure 3: the equivalent circuit shown in Figure 7, the third rectifier diode D ₃ is turned off at t ₃ , the primary winding LP of the coupled _inductor continues to charge, and the coupling The inductor secondary winding L ₂ continues to store energy, the first boost capacitor C ₁ continues to charge, and the output capacitor C _o supplies power to the load R.

The fifth switching mode corresponds to [t ₄ , t ₅ ] in Figure 3: the equivalent circuit is shown in Figure 8, at t ₄ the switch S is turned off, the parasitic capacitance of the switch begins to charge, and the first boost capacitor C ₁ Continue charging, and the output capacitor C _o supplies power to the load R.

The sixth switching mode corresponds to [t ₅ , t ₆ ] in FIG. 3 : the equivalent circuit is shown in FIG. 9 , the second rectifier diode D ₂ is turned on at time t ₅ , and the third boost capacitor C ₃ starts to charge, The first boost capacitor C ₁ begins to discharge, and the output capacitor C _o supplies power to the load R.

The seventh switching mode, corresponding to [t ₆ , t ₇ ] in Figure 3: the equivalent circuit shown in Figure 10, at t ₆ the output diode D _o is turned on, the first rectifier diode D ₁ is turned off, and the third rectifier diode D 1 is turned off. _The voltage capacitor C3 continues to charge, the first voltage boost capacitor _C1 and the _second voltage increase capacitor C2 are discharged, and the input power supply supplies power to the output capacitor _C0 and the load R.

The eighth switching mode corresponds to [t ₇ , t ₈ ] in FIG. 3 : the equivalent circuit shown in FIG. 11 , the diode D ₂ is turned off at time t ₇ , the first boost capacitor C ₁ and the second boost capacitor C 1 C ₂ discharges, and the input power supplies power to the output capacitor C _o and the load R.

From the above analysis, the gain expression can be obtained as:

Among them, D is the duty ratio of the switch tube S, and N is the turns ratio of the secondary side and the primary side of the coupled inductor.

The above is only the preferred embodiment of the present invention, it should be pointed out that: for those skilled in the art, without departing from the principle of the present invention, several improvements and modifications can also be made, and these improvements and modifications are also It should be regarded as the protection scope of the present invention.

Claims (3)

1. The hybrid lifting converter of coupling inductance is characterized in that: comprises a hybrid lifting coupling inductance network, a passive lossless clamping circuit and a filter capacitor C_oRectifier diode D_oAnd a resistive load R;

the hybrid power-lifting coupling inductance network comprises an input power supply V_inA first bootstrap circuit and a second bootstrap circuit; the first bootstrap circuit comprises a primary winding L of a coupling inductor_PSecondary winding L of coupled inductor_SA first rectifying diode D₁And a first boost capacitor C₁(ii) a The second bootstrap circuit comprises a secondary winding L of a coupling inductor_SA third rectifying diode D₃Switch tube S and first boost capacitor C₁A second boost capacitor C₂A third boost capacitor C₃；

The first boost capacitor C₁A third boost capacitor C₃And a second rectifying diode D₂Forming a passive lossless clamping circuit;

the input power supply V_inThe positive pole of the primary winding L is connected with the primary winding L of the coupling inductor_PFirst terminal of, first rectifying diode D₁Are connected simultaneously, the primary winding L_PThe second end of the first switch tube S, the drain electrode of the switch tube S and the first boost capacitor C₁Are connected simultaneously, and a secondary winding L of the inductor is coupled_SFirst terminal of and first boost capacitor C₁Positive electrode, second rectifying clampDiode D₂Coupled with the secondary winding L of the inductor_SSecond terminal and first rectifying diode D₁Cathode of (1), second boost capacitor C₂The cathodes are connected at the same time; third rectifier diode D₃Anode of and a second rectifying diode D₂Cathode of (2), third boost capacitor C₃Are connected at the same time, a third rectifier diode D₃Cathode and second boost capacitor C₂Anode, output diode D_oAre connected simultaneously, and a third boost capacitor C₃Negative electrode and filter capacitor C_oIs connected with the negative pole of the resistance load R at the same time, and an output diode D_oCathode and filter capacitor C_oThe positive electrode of the resistive load R and the positive electrode of the resistive load R are connected at the same time.

2. The coupled inductor hybrid boost converter of claim 1, wherein: the switch tube S is an MOS tube or an IGBT.

3. The coupled inductor hybrid boost converter of claim 1, wherein: the work of the coupling inductor hybrid lifting converter operates according to a working mode.

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