TWI581552B - Boost converter - Google Patents

Description

Boost converter

The present invention relates to a boost converter, and more particularly to a boost converter for electrically connecting a DC power source.

In many power generation systems, such as wind power, solar power, fuel cells, and hybrid vehicles, boost converters with high voltage conversion ratios (or high boost ratios) are needed to boost the output voltage of the front-end power generation terminals. To a higher voltage to provide power to the downstream load. In addition to the power supply system described above, boost converters with high voltage conversion ratios are also commonly used in other applications such as uninterruptible power systems (UPS), gas discharge headlamps (HID) for vehicles.

In view of this, many scholars have proposed many new high-boost converters, such as using the turns ratio of the coupled inductor to increase the voltage-gain ratio; or using the coupled inductor with a voltage doubler circuit, or with a switched capacitor. Voltage superposition is performed to further increase the voltage conversion ratio. However, the methods for improving the voltage conversion ratio mentioned above have their own shortcomings, including: some technologies use too many circuit components to cause complicated design, resulting in increased circuit cost, and some technologies use floating-type switches and must be isolated and driven; Some technologies require additional switches to implement active clamping circuits, which makes circuit analysis difficult. This inconvenience is often caused by the use of the upper boost converter.

The invention provides a boost converter device, which adopts a design of a double voltage circuit through a secondary side of two sets of coupled inductors, so that the energy storage units are superimposed to achieve a high boost ratio, and the use efficiency of the boost converter is improved. .

The invention provides a boost converter device electrically connected to a DC power source. Boost The conversion device includes a first coupled inductor, a second coupled inductor, a third coupled inductor, a fourth coupled inductor, a switch module, a first energy storage unit, a second energy storage unit, and a third storage The energy unit, a fourth energy storage unit and a fifth energy storage unit. The first coupled inductor is electrically connected to the DC power supply via a first leakage inductance for electrically coupling with a second coupled inductor, and the first coupled inductor is coupled in parallel with a first inductor. The third coupled inductor is electrically connected to the DC power source for electrically coupling with a fourth coupled inductor, and the third coupled inductor is coupled in parallel with a second inductor. The switch module is electrically connected to the first coupled inductor and the third coupled inductor. The first energy storage unit is electrically connected to the second coupled inductor via a first one-way communication unit. The second energy storage unit is electrically connected to the second coupled inductor via a second one-way communication unit. The third energy storage unit is electrically connected to the third coupled inductor via a second leakage inductance, and is electrically connected to the first coupled inductor via a third one-way conduction unit. The fourth energy storage unit is electrically connected to the fourth coupled inductor via a fourth one-way conduction unit. The fifth energy storage unit is electrically connected to the fourth coupled inductor via a fifth one-way conduction unit. The first energy storage unit, the second energy storage unit, the third energy storage unit, the fourth energy storage unit, and the fifth energy storage unit are connected in series, and the energy storage units connected in series are connected in parallel with a load.

The specific method of the present invention is to use a boost converter to pass the switching module to switch the charging and discharging operations of the inner loop of the boost converter, and to design the voltage doubler circuit on the secondary side of the two sets of coupled inductors. The energy storage units are superimposed to achieve a high boost ratio. In addition, when the switch module is turned off, the third energy storage unit recovers the energy of the first and second leakage inductors, thereby effectively clamping the voltage on the switch of the switch module. As such, the present embodiment is indeed suitable for application in high boost applications and improves the usability of the boost converter.

The above summary and the following examples are intended to be illustrative of the invention and the embodiments of the invention.

1‧‧‧Boost converter

L1‧‧‧First coupled inductor

L2‧‧‧Second coupled inductor

L3‧‧‧ Third coupled inductor

L4‧‧‧4th coupled inductor

LF‧‧‧first inductance

LS‧‧‧second inductance

Lk1‧‧‧First Leakage Inductance

Lk2‧‧‧Second leakage inductance

DS‧‧‧DC power supply

SM‧‧‧ switch module

S1‧‧‧ first switch

S2‧‧‧ second switch

C1~C5‧‧‧ energy storage unit, capacitor

D1~D5‧‧‧One-way unit, diode

RL‧‧ load

VGS1, VGS2, VDS1, VDS2, Vo‧‧‧ voltage

IL1, IL2, ILF, ILS, ID1, ID2, ID3, ID4, ID5, IN1, IN2, Ii, Io‧‧‧ Current

T, Ton‧‧‧

T0, t1, t2, t3‧‧‧ time

1 is a functional block diagram of a boost converter device according to an embodiment of the present invention.

2 is a circuit diagram of a boost converter device according to another embodiment of the present invention.

FIG. 3 is a schematic diagram of the operation of the switch module of the boost converter according to another embodiment of the present invention in an on state.

4 is a schematic diagram of the operation of the switch module of the boost converter according to another embodiment of the present invention in an off state.

FIG. 5 is a schematic diagram of the operation of the switch module of the boost converter according to another embodiment of the present invention in an off state.

Figure 6 is a diagram showing voltage and current waveforms of a boost converter according to another embodiment of the present invention.

FIG. 7 is a graph showing a relationship between an output voltage and a duty cycle of a conventional boost converter circuit according to another embodiment of the present invention.

1 is a functional block diagram of a boost converter device according to an embodiment of the present invention. Please refer to Figure 1. A boost converter device 1 is electrically connected to a DC power source DS. The boost converter device 1 includes a first coupled inductor L1, a second coupled inductor L2, a third coupled inductor L3, a fourth coupled inductor L4, a switch module SM, a first energy storage unit C1, and a first The second energy storage unit C2, a third energy storage unit C3, a fourth energy storage unit C4, a fifth energy storage unit C5, and a control module (not shown). In practice, the boost converter 1 is, for example, a boost circuit, a DC-DC boost converter circuit, or a switched-coupled inductive boost circuit with a voltage doubler circuit for converting a low voltage. For high voltage output. This embodiment does not limit the aspect of the boost converter device 1.

The DC power source DS is, for example, a low-voltage DC power source, such as a photovoltaic power source through solar panels, wind power, water or natural energy power generation, a battery or other power source. After the DC power source DS is boosted and converted by the boost converter device 1 of the embodiment, The output voltage is applied to the load RL. This embodiment does not limit the aspect of the DC power source DS.

In detail, the first coupled inductor L1 is electrically coupled to the DC power source DS via a first leakage inductor Lk1 for electrically coupling with a second coupled inductor L2, and the first coupled inductor L1 is coupled in parallel with a first inductor LF. In addition, the third coupled inductor L3 is electrically connected to the DC power source DS for electrically coupling with a fourth coupled inductor L4, and the third coupled inductor L3 is coupled in parallel with a second inductor LS. The first inductor LF and the second inductor LS are, for example, magnetizing inductances in the transformer. This embodiment does not limit the aspects of the first inductor LF and the second inductor LS.

In practice, the first coupled inductor L1 and the second coupled inductor L2 are, for example, a first set of transformers. The third coupled inductor L3 and the fourth coupled inductor L4 are, for example, a second set of transformers. The first coupled inductor L1 and the second coupled inductor L2 are respectively disposed, for example, in the primary side winding and the secondary side winding of the first group of transformers. The third coupled inductor L3 and the fourth coupled inductor L4 are respectively disposed, for example, in the primary side winding and the secondary side winding of the second group of transformers. This embodiment does not limit the aspects of the first, second, third, and fourth coupled inductors L1, L2, L3, and L4.

It is worth mentioning that the turns ratio of the first coupled inductor L1 and the second coupled inductor L2 is 1 to N, and the turns ratio of the third coupled inductor L3 to the fourth coupled inductor L4 is 1 to N, and N is greater than zero. The value. That is to say, the turns ratio of the two sets of transformers is such that the number of turns of the primary side winding is equal to or smaller than the number of turns of the secondary side winding, for example, 1:1, 1:2, 1:3 or 1:N. For example, N is for example 2. The turns ratio of the first and second coupled inductors L1 and L2 is the same as the turns ratio of the third and fourth coupled inductors L3 and L4, and the turns ratio is 1:2.

In practice, the transformer has a primary side winding and a secondary side winding corresponding to magnetic coupling. The primary side winding is, for example, the first or third coupled inductor L1, L3. The secondary side winding is, for example, a second or fourth coupled inductor L2, L4. The transformer transmits or converts energy through the magnetically coupled primary side winding and the secondary side winding, for example, the number of turns of the secondary side winding is greater than the number of turns of the primary side winding, whereby the transformer raises the voltage, for example, 15 volts. The voltage is regulated to a voltage of 400V volts. Of course, once The number of turns of the side windings can be equal to the number of turns of the secondary windings, whereby the transformer transfers energy.

In addition, the first leakage inductance Lk1 is electrically connected to the first coupled inductor L1. The second leakage inductance Lk2 is electrically connected to the third coupled inductor L3. The electric energy stored by the first leakage inductance Lk1 cannot be transmitted to the second coupled inductor L2. The electric energy stored in the second leakage inductance Lk2 cannot be transmitted to the fourth coupled inductor L4. Therefore, the electrical energy stored by the first and second leakage inductances Lk1, Lk2 is used to turn on or off the third conduction conducting unit. For example, the electrical energy stored by the first and second leakage inductances Lk1, Lk2 reaches a voltage of a conductive diode, thereby turning on the third conduction conducting unit. On the contrary, after the electric energy stored in the first and second leakage inductances Lk1, Lk2 is released, the third unidirectional conduction unit D3 is turned off. The third unidirectional conduction unit D3 is, for example, a flywheel diode.

The switch module SM is electrically connected to the first coupled inductor L1, the third coupled inductor L3, the first leakage inductor Lk1, and the second leakage inductor Lk2. In practice, the switch module SM is implemented, for example, by a plurality of power transistors, gate transistors, or field effect transistors. The switch module SM is controlled by the control signal, the pulse width modulation signal or the synchronization signal output by the control module. This embodiment does not limit the aspect of the switch module SM.

It is worth mentioning that the control module is electrically connected to the switch module SM. In practice, the control module is, for example, a central processing unit (CPU), a micro processing unit (MCU), a digital signal processor (Digital Signal Processor), or a control chip for performing signal calculation and processing in the boost converter device 1. Switch the job with the control switch. This embodiment does not limit the aspect of the control module.

Further, the control module controls the synchronous conduction or the synchronous cutoff of the plurality of switches in the switch module SM through the synchronization signal. The synchronization signal includes, for example, a plurality of identical pulse width modulation signals. That is to say, the switches in the switch module SM will be turned on or off simultaneously according to the synchronization signal.

A first energy storage unit C1 is electrically connected to the second coupled inductor L2 via a first one-way conduction unit D1. a second energy storage unit C2 via a second one-way unit D2 is electrically connected to the second coupled inductor L2. A third energy storage unit C3 is electrically connected to the third coupled inductor L3 via a second leakage inductance Lk2, and is electrically connected to the first coupled inductor L1 via a third one-way conduction unit D3. A fourth energy storage unit C4 is electrically connected to the fourth coupled inductor L4 via a fourth unidirectional conduction unit D4. A fifth energy storage unit C5 is electrically connected to the fourth coupled inductor L4 via a fifth one-way conduction unit D5.

In practice, the first, second, third, fourth, and fifth energy storage units C1, C2, C3, C4, and C5 are respectively realized by a capacitor or an electrolytic capacitor. This embodiment does not limit the aspects of the first, second, third, fourth, and fifth energy storage units C1, C2, C3, C4, and C5. The first energy storage unit C1, the second energy storage unit C2, the third energy storage unit C3, the fourth energy storage unit C4, and the fifth energy storage unit C5 are connected in series, and the energy storage units C1 and C2 are connected in series. C3, C4, C5 are connected in parallel with a load RL. That is, this embodiment can provide a higher output voltage to the load RL.

In addition, the first, second, third, fourth, and fifth unidirectional conduction units D1, D2, D3, D4, and D5 are respectively realized by a diode. The one-way conduction units D1, D2, D3, D4, and D5 are, for example, unidirectional components in the boost converter circuit, thereby limiting the flow of current in the boost converter circuit. This embodiment does not limit the aspects of the first, second, third, fourth, and fifth unidirectional conduction units D1, D2, D3, D4, and D5.

It is worth mentioning that the first and second one-way conduction units D1, D2, the first and second energy storage units C1, C2 are a full bridge type voltage doubler circuit. The fourth and fifth one-way conduction units D4, D5, the fourth and fifth energy storage units C4, C5 are another full bridge type voltage doubler circuit. That is to say, this embodiment has two sets of voltage doubler circuits. The operation of the boost converter device 1 of the present embodiment is as follows: for example, when the switch module SM is in an on state, the first coupled inductor L1 and the third coupled inductor L3, A leakage inductance Lk1, a second leakage inductance Lk2, a first inductance LF, and a second inductance LS are respectively in a charged state. The first coupled inductor L1 transfers the electrical energy to the second coupled inductor L2, thereby turning on the first unidirectional conduction unit D1 to charge the first energy storage unit C1. Similarly, the third coupled inductor L3 will be electric energy. It is passed to the fourth coupled inductor L4, thereby turning on the fourth unidirectional conduction unit D4 to charge the fourth energy storage unit C4. The second, third, and fifth energy storage units C2, C3, and C5 are in a discharged state, thereby supplying power to the load RL. That is, the first and fourth energy storage units C1, C4 are in a state of charge. The second, third, and fifth energy storage units C2, C3, and C5 are in a discharged state, thereby supplying power to the load RL.

On the other hand, when the switch module SM is in the off state, the first and second leakage inductances Lk1, Lk2 release electric energy, thereby turning on the third one-way conduction unit D3. The electric energy released by the first and second leakage inductances Lk1 and Lk2 charges the third energy storage unit C3, whereby the electric energy is recovered and the electric energy is accumulated on the switch module SM, thereby achieving the effective clamp switch module SM. The voltage on it.

In addition, a part of the electric energy of the first inductance LF is transmitted through the third one-way conduction unit D3 to charge the third energy storage unit C3. Another portion of the electrical energy of the first inductance LF and the electrical energy of the direct current power supply DS will be converted to the second coupled inductor L2 through the first coupled inductor L1, thereby turning on the second unidirectional conduction unit D2 to charge the second energy storage unit C2. Similarly, a part of the electric energy of the second inductor LS passes through the third one-way conduction unit D3 to charge the third energy storage unit C3. Another portion of the electrical energy of the second inductor LS and the electrical energy of the direct current power source DS are converted to the fourth coupled inductor L4 through the third coupled inductor L3, thereby turning on the fifth unidirectional conduction unit D5 to charge the fifth energy storage unit C5. That is to say, the second, third and fifth energy storage units C2, C3, C5 are in a charging state, and the first and fourth energy storage units C1, C4 are in a discharging state to supply power to the load RL.

Thereafter, when the switch module SM is still in the off state, the power of the first and second leakage inductances Lk1, Lk2 is released, and the third one-way conduction unit D3 is turned off. The electric energy stored in the first inductor LF is all converted to the second coupled inductor L2 through the first coupled inductor L1, thereby turning on the second unidirectional conduction unit D2 to charge the second energy storage unit C2. Similarly, the electrical energy stored in the second inductor LS is all converted to the fourth coupled inductor L4 through the third coupled inductor L3, thereby turning on the fifth unidirectional conduction unit D5 to charge the fifth energy storage unit C5. In other words, the second and fifth energy storage units C2, C5 The system is in a state of charge, and the first, third, and fourth energy storage units C1, C3, and C4 are in a discharged state to supply power to the load RL.

Based on the above, the embodiment uses a switched inductive boost converter as a structure, and a double voltage circuit is used on the secondary side of the transformer, so that the energy storage units C1, C2, C3, C4, and C5 are superimposed to achieve High boost ratio. The architecture of the switched inductive boost converter includes, for example, a switch module SM, a first coupled inductor L1, a first leakage inductance Lk1, a first inductor LF, a third one-way conduction unit D3, and a third energy storage unit C3. The third coupled inductor L3, the second leakage inductor Lk2, and the second inductor LS. In addition, when the switch module SM is turned off, the energy of the first and second leakage inductances Lk1 and Lk2 is recovered by the third energy storage unit C3, thereby effectively clamping the voltage on the power switch of the switch module SM. . And because the voltage on the output load end is superimposed through the energy storage units C1, C2, C3, C4, and C5, the problem of effectively reducing the withstand voltage of each of the energy storage units C1, C2, C3, C4, and C5 can be achieved. In this way, the volume of each of the energy storage units C1, C2, C3, C4, and C5 can be reduced, and a larger margin can be obtained in selecting each of the energy storage units C1, C2, C3, C4, and C5.

In addition, when the conventional step-up power converter operates at a high step-up ratio, due to the parasitic components in the circuit, it will cause a large conduction loss when the duty cycle is too large; therefore, the switching mode of the conventional step-up power converter The duty cycle of the group is limited, making the conventional step-up power converter unable to achieve the higher boost ratio. Furthermore, since the voltage stress on the switch module is equal to the output voltage on the output load terminal, it is necessary to use a switch with a higher voltage stress but a higher on-resistance, which will increase the conduction loss on the switch, so it is not suitable. Applied in high boost applications. However, this embodiment can overcome the problems caused by the conventional boost type power converter described above.

2 is a circuit diagram of a boost converter device according to another embodiment of the present invention. Please refer to Figure 2. For convenience of description, the switch module SM of the present embodiment includes two switches S1 and S2 for explanation. The switch module SM includes a first switch S1 and a second switch S2. For convenience of explanation, the first of the coupled inductors L1, L2, L3, L4 The terminal is, for example, a current input terminal, and the second terminal of the coupling inductors L1, L2, L3, L4 is, for example, a current output terminal.

The first, second, third, fourth and fifth unidirectional conduction units shown in FIG. 2 are respectively a diode D1, D2, D3, D4, D5. The first, second, third, fourth and fifth energy storage units are respectively a capacitor C1, C2, C3, C4, C5. The first switch S1 and the second switch S2 are respectively a gate transistor. The drain of the first switch S1 is electrically connected to the first leakage inductance Lk1. The first leakage inductance Lk1 is electrically connected to the first end of the first coupled inductor L1. The source of the first switch S1 is electrically connected to the second leakage inductance Lk2. The second leakage inductance Lk2 is electrically connected to the first end of the third coupled inductor L3. The drain of the second switch S2 is electrically connected to the second end of the first coupled inductor L1. The source of the second switch S2 is electrically connected to the second end of the third coupled inductor L3.

The first and second inductors LF, LS of the present embodiment operate in a continuous conduction mode (CCM). The inductance values of the first and second inductors LF and LS are the same. The output capacitors C1, C2, C3, C4, and C5 have large capacitance values and can be regarded as constant voltage sources. The turns ratio of the first and second coupled inductors L1, L2 is 1 to N, and the turns ratio of the third and fourth coupled inductors L3, L4 is 1 to N, and N is a value greater than zero. The turns ratio of the first and second coupled inductors L1, L2 is the same as the turns ratio of the third and fourth coupled inductors L3, L4.

The control module outputs a synchronization signal to the first switch S1 and the second switch S2 of the switch module SM to control the synchronous conduction or synchronous cutoff of the first switch S1 and the second switch S2. That is to say, the control module controls the on/off pulse width modulation signal of the first switch S1 to be synchronized with the pulse width modulation signal that controls the on or off of the second switch S2.

The first end of the first coupled inductor L1 is electrically connected to the anode of the DC power source DS and the first switch S1 of the switch module SM via a first leakage inductance Lk1. The second end of the first coupled inductor L1 is electrically connected to the first pole of the diode D3 and the second switch S2 of the switch module SM. The first end of the second coupled inductor L2 is electrically connected between the diode D1 and the diode D2. The second end of the second coupled inductor L2 is electrically connected to the capacitor C1 and the electric Between C2. The first end of the fourth coupled inductor L4 is electrically connected between the diode D4 and the diode D5. The second end of the fourth coupled inductor L4 is electrically connected between the capacitor C4 and the capacitor C5.

The first end of the third coupled inductor L3 is electrically connected to the first switch S1 and the capacitor C3 of the switch module SM via a second leakage inductance Lk2. The second end of the third coupled inductor L3 is electrically connected to the cathode of the DC power source DS and the second switch S2 of the switch module SM.

For example, when the first and second switches S1 and S2 are in an on state, the DC power source DS is charged to the first coupled inductor L1, the third coupled inductor L3, the first leakage inductor Lk1, the second leakage inductor Lk2, and the first inductor. LF and second inductor LS. The first coupled inductor L1 converts electrical energy to the second coupled inductor L2, and the electrical energy flows through the diode D1 to charge the capacitor C1. Similarly, the third coupled inductor L3 converts electrical energy to the fourth coupled inductor L4, and the electrical energy flows through the diode D4 to charge the capacitor C4. That is to say, the capacitors C1 and C4 are in a charged state. The capacitors C2, C3, and C5 are in a discharged state, thereby supplying power to the load RL.

When the first and second switches S1, S2 are in the off state, the electrical energy stored by the first and second leakage inductances Lk1, Lk2 will be released to turn on the diode D3. A portion of the electrical energy of the first inductance LF and the electrical energy of the direct current power supply DS will charge the capacitor C3. The first coupled inductor L1 converts electrical energy to the second coupled inductor L2, and the electrical energy flows through the diode D2 to charge the capacitor C2. Similarly, the third coupled inductor L3 converts electrical energy to the fourth coupled inductor L4, and the electrical energy flows through the diode D5 to charge the capacitor C5. That is to say, the capacitors C2, C3, and C5 are in a charged state. The capacitors C1 and C4 are in a discharged state, thereby supplying power to the load RL.

Then, after the electric energy stored in the first and second leakage inductances Lk1, Lk2 is released, the diode D3 is turned off. The first inductor LF is discharged to the first coupled inductor L1, and the first coupled inductor L1 converts the electrical energy to the second coupled inductor L2, and the electrical energy is passed through the diode D2 to charge the capacitor C2. Similarly, the second inductor LS is discharged to the third coupled inductor L3, and the third coupled inductor L3 converts the electric energy to the fourth coupled inductor L4, and the electric energy is charged to the capacitor C5 via the diode D5. That is to say, the capacitors C2 and C5 are in a charged state. Capacitance C1, C3, and C4 are in a discharged state, thereby supplying power to the load RL.

Next, the detailed operation of the boost converter device 1 will be further explained.

FIG. 3 is a schematic diagram of the operation of the switch module of the boost converter according to another embodiment of the present invention in an on state. Please refer to Figure 3. Please also cooperate with the timing diagram of the voltage and current waveforms in Figure 6.

In interval one (t0~t1), t0≦ time t<t1. When the time t=t0, the first switch S1 and the second switch S2 are simultaneously turned on, and the diodes D2, D3, and D5 are reverse biased off. The input voltage is across the first and third coupled inductors L1, L3 of the primary winding, and the energy is stored in magnetic energy at the first and second inductances LF, LS. At the same time, the energy of the primary winding is transmitted to the second and fourth coupled inductors L2 and L4 of the secondary winding, and respectively charges the output capacitors C1 and C4 through the diodes D1 and D4, respectively, and supplies energy to the load RL. . The currents ILF and ILS on the first inductor LF and the second inductor LS have a linear rising waveform, and the waveforms of the currents IN1 and IN2 of the second and fourth coupled inductors L2 and L4 of the secondary winding also have a linear rising waveform, as shown in the figure. 6 is drawn.

4 is a schematic diagram of the operation of the switch module of the boost converter according to another embodiment of the present invention in an off state. Please refer to Figure 4. Please also cooperate with the timing diagram of the voltage and current waveforms in Figure 6.

In interval two (t1~t2), t1≦ time t<t2. When the time t=t1, the first and second switches S1 and S2 are simultaneously turned off, and the diodes D1 and D4 are reverse biased off. The diode D3 is forced to conduct due to the release of energy by the first and second leakage inductances Lk1, Lk2. Since the energy of the first and second leakage inductances Lk1, Lk2 is released to the output capacitor C3, the energy is recovered and does not accumulate on the first and second switches S1, S2, thereby effectively clamping the first and second switches The voltage on S1 and S2. A part of the energy of the first inductor LF and the second inductor LS charges the output capacitor C3 through the diode D3, and transmits the energy of the other part and the energy provided by the input voltage to the second winding of the secondary side. And the fourth coupled inductors L2, L4, the output capacitors C2 and C5 are charged through the diodes D2 and D5, and the load RL is energized.

At this time, the current ILF and ILS waveforms are linearly falling. The waveforms of the currents IN1, IN2 of the second and fourth coupled inductors L2, L4 of the secondary winding respectively have a linear rising waveform. This is because the current ILF on the first inductance LF is equal to the current IL1 on the first leakage inductance Lk1 plus the current on the first coupling inductance L1 of the primary side winding. Moreover, since the slope of the first inductor LF current ILF decreases is smaller than the slope of the current IL1 drop of the first leakage inductor Lk1, the second coupled inductor L2 current waveform of the secondary winding has a linear rising waveform and is mapped back to the primary winding. The first coupled inductor L1.

Similarly, the current ILS on the second inductor LS is equal to the current IL2 on the second leakage inductance Lk2 plus the current on the third coupled inductor L3 of the primary winding. Because the slope of the second inductor LS current ILS decreases is smaller than the slope of the current IL2 drop of the second leakage inductor Lk2, the fourth coupled inductor L4 current waveform of the secondary winding has a linear rising waveform and is mapped back to the primary winding. The third coupled inductor L3 is as shown in FIG.

FIG. 5 is a schematic diagram of the operation of the switch module of the boost converter according to another embodiment of the present invention in an off state. Please refer to Figure 5. Please also cooperate with the timing diagram of the voltage and current waveforms in Figure 6.

In interval three (t2~t3), t2≦ time t<t3. The first and second switches S1, S2 remain in an off state, and the diodes D1, D3, D4 remain reverse biased off. At this time, the energy stored on the first and second leakage inductances Lk1, Lk2 is released, and the current on the diode D3 falls to zero and is turned off. The energy on the first and second inductors LF, LS is transmitted through the first and third coupled inductors L1, L3 of the primary winding to the second and fourth coupled inductors L2, L4 of the secondary winding to provide an output. Load RL energy. The current ILF and ILS waveforms of the first and second inductors LF, LS have linearly falling waveforms, respectively. The waveforms of the currents IN1 and IN2 of the second and fourth coupled inductors L2, L4 of the secondary winding have a linear decreasing waveform, as shown in FIG.

When the interval three ends, the circuit action returns to the interval one and enters the next switching cycle. This embodiment does not limit the operational aspect of the boost converter device 1.

Figure 6 is a diagram showing the power of the boost converter 1 according to another embodiment of the present invention Pressure and current waveforms. Please refer to Figure 6. Figure 6 shows two voltage waveform diagrams and six current waveform diagrams, including the gate voltages VGS1, VGS2 of a switch S1, S2; the voltages VDS1, VDS2 between the drain and the source of a switch S1, S2 Waveform; current IL1, IL2 waveforms of first and second leakage inductances Lk1, Lk2; current ILF, ILS waveforms of first and second inductances LF, LS; current ID3 waveform of one diode D3; The currents ID1 and ID4 waveforms of the bodies D1 and D4; the current ID2 and ID5 waveforms of the diodes D2 and D5; and the currents IN1 and IN2 of the second and fourth coupled inductors L2 and L4. The interval Ton is the conduction time of the conduction switch module SM. The interval T is the duty cycle of a switch module SM. This embodiment does not limit the state of the voltage and current waveforms of the boost converter device 1.

FIG. 7 is a graph showing a relationship between an output voltage and a duty cycle of a conventional boost converter circuit according to another embodiment of the present invention. Please refer to Figure 7. FIG. 7 is a graph showing six output voltage-responsibility periods, including an output voltage-response period curve of a boost converter of the present embodiment, and an output voltage of a conventional double-voltage coupled inductive boost converter. The duty cycle curve, the output voltage of a conventional switched inductive boost converter - the duty cycle curve, the output voltage of a conventional boost converter - the duty cycle curve, a conventional stacked boost type forward The output voltage-duty cycle curve of the converter, and the output voltage-response period curve of a conventional stacked boost-type flyback converter.

As can be seen from FIG. 7, this embodiment can achieve the purpose of boosting in a small duty cycle. For example, in the case of boosting to 200 volts, this embodiment can achieve boosting to 200 volts with a duty cycle of about 0.5. Conventional double-voltage coupled inductive boost converters, conventional switched inductive boost converters, conventional boost converters, conventional stacked boost forward converters, and conventional stacked boost converters The flyback converters must be boosted to 200 volts with a duty cycle of approximately 0.7 to 0.9. In brief, this embodiment improves the problem that other boost converters have to achieve a high boost ratio, resulting in an excessively large duty cycle resulting in inefficient efficiency.

In summary, the present invention is a boost converter device that includes a switch module, The first inductive inductor, the first leakage inductance, the first inductance, the third one-way conduction unit, the third energy storage unit, the third coupling inductance, the second leakage inductance, and the second inductance switching inductive boost converter are The structure uses a voltage doubler circuit on the secondary side of the two sets of coupled inductors, so that the energy storage units are superimposed to achieve a high boost ratio. In addition, when the switch module is turned off, the third energy storage unit recovers the energy of the first and second leakage inductors, thereby effectively clamping the voltage on the switch of the switch module. Moreover, since the voltage on the output load terminal is superimposed through the capacitors, the problem of effectively reducing the withstand voltage of each capacitor can be achieved, so that the volume of each capacitor can be reduced. In addition, in this embodiment, the voltage division on each capacitor can be adjusted through the turns ratio, so that the voltage stress of the switch of the switch module can be limited to a required range, and has great advantages in selecting circuit components. . As such, the present embodiment is indeed suitable for application in high boost applications and improves the usability of the boost converter.

The above description is only an embodiment of the present invention, and is not intended to limit the scope of the invention.

1‧‧‧Boost converter

L1‧‧‧First coupled inductor

L2‧‧‧Second coupled inductor

L3‧‧‧ Third coupled inductor

L4‧‧‧4th coupled inductor

LF‧‧‧first inductance

LS‧‧‧second inductance

Lk1‧‧‧First Leakage Inductance

Lk2‧‧‧Second leakage inductance

DS‧‧‧DC power supply

SM‧‧‧ switch module

C1~C5‧‧‧ energy storage unit

D1~D5‧‧‧One-way unit

RL‧‧ load

Claims (13)

A boost converter device is electrically connected to a DC power source. The boost converter device includes: a first coupled inductor electrically connected to the DC power source via a first leakage inductor for electrically coupling with a second coupled inductor. The first coupled inductor is connected in parallel with a first inductor; a third coupled inductor is electrically connected to the DC power source for electrically coupling with a fourth coupled inductor, and the third coupled inductor is connected in parallel with a second inductor a switch module electrically connecting the first coupled inductor and the third coupled inductor; and a first energy storage unit electrically connected to the second coupled inductor via a first one-way conduction unit; The energy storage unit is electrically connected to the second coupled inductor via a second one-way conduction unit; the third energy storage unit is electrically connected to the third coupled inductor via a second leakage inductance, and via a third one-way The first coupling inductor is electrically connected to the first coupling inductor; the fourth energy storage unit is electrically connected to the fourth coupling inductor via a fourth one-way conduction unit; and the fifth energy storage unit is connected to the fifth Guide unit Electrically connecting the fourth coupled inductor; wherein the first energy storage unit, the second energy storage unit, the third energy storage unit, the fourth energy storage unit, and the fifth energy storage unit are connected in series, and are connected in series The energy storage unit is connected in parallel with a load; wherein, when the switch module is in an off state, the first leakage inductance and the second leakage inductance release electrical energy, thereby turning on the third one-way conduction unit, wherein the first leakage current Sense of the electrical energy released by the second leakage inductance will charge the third energy storage unit to avoid accumulation of electrical energy in the switch module. The boost converter device of claim 1, further comprising a control module, wherein the control module outputs a synchronization signal to a first switch and a second switch of the switch module to control the first switch and The second switch is turned on or off synchronously. The boost converter device of claim 2, wherein the first end of the first coupled inductor is electrically connected to the anode of the DC power source and the first switch of the switch module via the first leakage inductance, the first A second end of the coupled inductor is electrically connected to the first pole of the third one-way unit and the second switch of the switch module. The boost converter device of claim 2, wherein the first end of the third coupled inductor is electrically connected to the first switch and the third energy storage unit of the switch module via the second leakage inductance, The second end of the third coupled inductor is electrically connected to the cathode of the DC power source and the second switch of the switch module. The boost converter device of claim 2, wherein the first end of the second coupled inductor is electrically connected to the first unidirectional pass unit and the second unidirectional pass unit, and the second end of the second coupled inductor Electrically connecting the first energy storage unit and the second energy storage unit, the first end of the fourth coupled inductor is electrically connected to the fourth unidirectional conduction unit and the fifth unidirectional conduction unit, and the fourth coupled inductor The second end is electrically connected to the fourth energy storage unit and the fifth energy storage unit. The boost converter device of any one of claims 1 to 5, wherein when the switch module is in an on state, the DC power source is charged to the first leakage inductance, the first coupled inductor, the first inductor, and the a second leakage inductance, the third coupled inductor and the second inductor, the first coupled inductor converting electrical energy to the second coupled inductor, and the electrical energy flowing through the first one-way conduction unit to charge the first energy storage unit, The third coupled inductor converts electrical energy to the fourth coupled inductor, and the electrical energy flows through the fourth unidirectional pass unit to charge the fourth energy storage unit. The boost converter device of claim 6, wherein the third energy storage unit recovers energy of the first leakage inductance and the second leakage inductance when the switch modules are turned off to clamp the switch module Voltage. A boost converter according to any one of claims 1 to 5, wherein the switch mode When the group is in an off state, the first leakage inductance and the second leakage inductance release electrical energy to turn on the third one-way conduction unit, and the first leakage inductance and the second leakage inductance release the electrical energy to the first The third energy storage unit is charged, and the first inductor and a portion of the second inductor pass through the third unidirectional conduction unit to charge the third energy storage unit, and another portion of the first inductor and the DC power source The electrical energy is converted to the second coupled inductor through the first coupled inductor, such that the second unidirectional conduction unit is turned on to charge the second energy storage unit, and another portion of the electrical energy of the second inductor and the power of the DC power source pass through the The third coupled inductor is switched to the fourth coupled inductor such that the fifth unidirectional conduction unit is turned on to charge the fifth energy storage unit. The boost converter device of claim 8, wherein the first leakage inductance and the second leakage inductance are discharged, the third one-way conduction unit is turned off, and the first inductor is discharged to the first coupled inductor. The first coupled inductor converts electrical energy to the second coupled inductor, the electrical energy is charged to the second energy storage unit via the second one-way conduction unit, and the second inductor is discharged to the third coupled inductor, the third coupled inductor Converting electrical energy to the fourth coupled inductor, the electrical energy is passed through the fifth one-way conduction unit to charge the fifth energy storage unit. The boost converter according to any one of claims 3 to 5, wherein the first end is a current input end of each of the coupled inductors, and the second end is a current output end of each of the coupled inductors. The boost converter device of claim 1, wherein the first coupled inductor and the second coupled inductor are a first transformer, and the first coupled inductor and the second coupled inductor have a turns ratio of 1 to N, The third coupled inductor and the fourth coupled inductor are a second transformer, and the third coupled inductor and the fourth coupled inductor have a turns ratio of 1 to N, and N is a value greater than zero. The boost converter device of claim 1, wherein the inductance of the first coupled inductor is the same as the inductance of the third coupled inductor, and the first coupling inductor and the second coupled inductor have the same turns ratio. a third coupled inductor and the fourth coupling The turns ratio of the inductor. The boost converter device of claim 2, wherein the first inductor and the second inductor are respectively a magnetizing inductance, and the one-way conducting units are respectively a diode, and the energy storage units are respectively a capacitor. The first switch and the second switch are respectively a gate transistor.