KR102384581B1 - Boost converter with decoupling operation - Google Patents

Abstract

The present invention relates to a boost converter capable of performing both a boosting operation and an active decoupling operation. A boost converter according to an embodiment of the present invention includes a full-bridge rectification circuit for rectifying an AC power including first and second switching elements connected to at least one leg, the full-bridge rectification A decoupling circuit connected to the output terminal of the circuit, the decoupling circuit including a buffer capacitor and a decoupling inductor receiving power from the buffer capacitor, and controlling the first and second switching elements to charge power to the buffer capacitor or the and a control unit supplying power charged in a buffer capacitor to the decoupling inductor, and an output circuit connected to an output terminal of the decoupling circuit to receive power from the decoupling inductor.

Description

BOOST CONVERTER WITH DECOUPLING OPERATION

The present invention relates to a boost converter capable of performing both a boosting operation and an active decoupling operation.

The converter includes a diode and a power switching device, and converts power through current interruption using the diode and the power switching device. In particular, since the power switching element is controlled to be in an on-state or an off-state to regulate the current, the current or voltage in the converter rapidly changes, which generates noise. In order to prevent the generated noise from being provided to the load, a decoupling capacitor is generally provided in the converter.

1 is a circuit diagram of a conventional boost converter. Hereinafter, a decoupling operation performed in the conventional boost converter will be described with reference to FIG. 1 .

When the power switching element S is turned on, the AC current output from the AC voltage source Vac is converted into DC current through a plurality of diodes D1, D2, D3, and D4 connected in a full-bridge form. It is converted and stored in the inductor (L). Thereafter, when the power switching element S is controlled to be turned off, the DC current converted through the plurality of diodes D1 , D2 , D3 , and D4 and the DC current stored in the inductor L are provided to the load R.

At this time, noise due to the switching operation is generated in the power switching device S, and in order to prevent the noise from being provided to the load, the conventional boost converter includes a decoupling capacitor C connected in parallel with the load.

The decoupling capacitor C performs a passive decoupling operation. Specifically, the decoupling capacitor C flows the power of the AC component provided to the load to the ground, so that only the stable power of the DC component is supplied to the load.

For this function, a large capacity of the decoupling capacitor C is required, and accordingly, an electrolytic capacitor has been used as the decoupling capacitor C.

However, in recent years, electrolytic capacitors have been replaced with film capacitors in order to miniaturize converters, improve power conversion efficiency, and increase lifespan. can't do it right

Accordingly, there is a need for a converter capable of performing an active decoupling operation instead of a passive decoupling operation based on the capacitance of the capacitor.

An object of the present invention is to provide a boost converter in which a switching element used for a boosting operation and a switching element used for a decoupling operation are shared.

Another object of the present invention is to provide a boost converter capable of replacing an output capacitor for supplying a voltage to a load from an electrolytic capacitor to a film capacitor.

The objects of the present invention are not limited to the above-mentioned objects, and other objects and advantages of the present invention not mentioned may be understood by the following description, and will be more clearly understood by the examples of the present invention. It will also be readily apparent that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the appended claims.

The present invention controls two switching elements connected to one leg of a full-bridge rectifier circuit to charge or discharge a boosting inductor, and at the same time charge or discharge a buffer capacitor and a decoupling inductor according to the operation of the two switching elements. The switching element used for the boosting operation and the switching element used for the decoupling operation can be shared.

In addition, the present invention includes a decoupling circuit for performing an active decoupling operation inside a general AC-DC converter, so that an output capacitor for supplying a voltage to a load can be replaced with a film capacitor from an electrolytic capacitor.

According to the present invention, by sharing the switching element used for the boosting operation and the switching element used for the decoupling operation, it is possible to actively block the noise of the AC component that can be supplied to the load without a separate switching element for the decoupling operation.

In addition, according to the present invention, by replacing the output capacitor for supplying a voltage to the load from the electrolytic capacitor to the film capacitor, the boost converter can be miniaturized, the power conversion efficiency can be improved, and the lifespan can be increased.

In addition to the above-described effects, the specific effects of the present invention will be described together while describing specific details for carrying out the invention below.

1 is a view for explaining the operation of a conventional boost converter.
2 is a diagram schematically illustrating the configuration of a boost converter according to an embodiment of the present invention.
3A and 3B respectively illustrate exemplary circuits of the full bridge rectifier circuit shown in FIG. 2;
4A and 4B respectively illustrate exemplary circuits of the decoupling circuit shown in FIG. 2;
5 is a circuit diagram of a boost converter according to an embodiment of the present invention.
6 is a waveform diagram for explaining a decoupling operation through charging and discharging of a buffer capacitor and a decoupling inductor.
7A to 7C are views illustrating current flow for each mode shown in FIG. 6;

The above-described objects, features and advantages will be described below in detail with reference to the accompanying drawings, and accordingly, those of ordinary skill in the art to which the present invention pertains will be able to easily implement the technical idea of the present invention. In describing the present invention, if it is determined that a detailed description of a known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description will be omitted. Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to indicate the same or similar components.

In this specification, the first, second, etc. are used to describe various components, but these components are not limited by these terms. These terms are only used to distinguish one component from other components, and unless otherwise stated, it goes without saying that the first component may be the second component.

In addition, when it is described in this specification that a component is “connected”, “coupled” or “connected” to another component, the components may be directly connected or connected to each other, but other components may be formed between each component. It should be understood that elements may be “interposed”, or that each element may be “connected,” “coupled,” or “connected to,” through another element.

Also, as used herein, the singular expression includes the plural expression unless the context clearly dictates otherwise. In the present application, terms such as “consisting of” or “comprising” should not be construed as necessarily including all of the various components or various steps described in the specification, some of which components or some steps are It should be construed that it may not include, or may further include additional components or steps.

In addition, in this specification, when "A and / or B" is said, unless otherwise stated, it means A, B or A and B, and when said "C to D", it is Unless otherwise specified, it means C or more and D or less

The present invention relates to a boost converter capable of performing both a boosting operation and an active decoupling operation.

Hereinafter, a boost converter according to an embodiment of the present invention will be described in detail with reference to the drawings.

2 is a diagram schematically illustrating a configuration of a boost converter according to an embodiment of the present invention.

3A and 3B are diagrams respectively illustrating exemplary circuits of the full bridge rectifying circuit shown in FIG. 2 . 4A and 4B are diagrams respectively illustrating exemplary circuits of the decoupling circuit shown in FIG. 2 .

5 is a circuit diagram of a boost converter according to an embodiment of the present invention.

6 is a waveform diagram for explaining a decoupling operation through charging and discharging of a buffer capacitor and a decoupling inductor, and FIGS. 7A to 7C are diagrams illustrating current flow for each mode shown in FIG. 6 .

2, the boost converter 100 according to an embodiment of the present invention is a full-bridge rectifier circuit 110, a decoupling circuit 120, a control unit 130, and an output circuit ( 140) may be included. The boost converter 100 shown in FIG. 2 is according to an embodiment, and its components are not limited to the embodiment shown in FIG. 2 , and some components may be added, changed, or deleted as necessary. .

On the other hand, the control unit 130 to be described later is ASICs (application specific integrated circuits), DSPs (digital signal processors), DSPDs (digital signal processing devices), PLDs (programmable logic devices), FPGAs (field programmable gate arrays), processors (processors) ), controllers, microcontrollers, and microprocessors may be implemented as at least one physical element.

The full-bridge rectification circuit 110 may rectify the AC power Vac using a plurality of semiconductor devices connected in a full-bridge form. The full-bridge rectification circuit 110 includes two legs, and two pairs of semiconductor devices are connected to each leg in a totme-pole structure to rectify the AC power Vac.

Referring to FIG. 3A , the structure of the full bridge rectifier circuit 110 according to an example will be described. The full bridge rectifier circuit 110 has one end of the boosting inductor (Lb) connected to the system, the other of the boosting inductor (Lb). It may include a first leg 110a connected to the end and a second leg 110b connected in parallel to the first leg 110a. At this time, the first and second diodes D1 and D2 may be connected as a pair to the first leg 110a, and the first and second switching elements S1 and S2 to the second leg 110b. can be connected as a pair.

Basically, the positive AC current supplied from the AC power supply Vac is provided to the output terminal through the first diode D1 and the second switching element S2, and the negative AC current supplied from the AC power supply Vac is the second By being inverted through the second diode D2 and the first switching element S1 and provided to the output terminal, the AC power Vac may be full-wave rectified. To this end, the controller 130 may provide a switching control signal synchronized with the phase of the AC power source Vac to the first and second switching elements S1 and S2 .

Referring to FIG. 3b, the structure of the full-bridge rectifier circuit 110 according to another example is described. The full-bridge rectifier circuit 110 includes a boosting inductor Lb, a first leg 110a and A second leg 110b may be included. In this case, the first and second diodes D1 and D2 may be connected as a pair to the first leg 110a. The third and fourth switching elements S3 and S4 may be connected as a pair to the second leg 110b.

Basically, the positive AC supplied from the AC power source Vac is provided to the output terminal through the first and fourth switching elements S1 and S4, and the negative AC current supplied from the AC power source Vac is applied to the second and second switching devices S1 and S4. 3 By being inverted through the switching elements S2 and S3 and provided to the output terminal, the AC power Vac may be full-wave rectified. To this end, the controller 130 may provide each of the switching control signals synchronized with the phase of the AC power source Vac to the first to fourth switching elements S1 , S2 , S3 , and S4 .

In this rectification process, a boosting operation may be performed. More specifically, in the rectification process, the boosting inductor Lb may charge power output from the AC power source Vac, and the charged power may be provided to the output terminal circuit 140 to be described later. To this end, the controller 130 may control the first and second switching elements S1 and S2, which will be described later.

The above-described full-bridge rectification circuit 110 may be connected to an arbitrary AC power source (Vac). For example, the full-bridge rectification circuit 110 may be connected to a grid (eg, commercial AC power) and may rectify the AC power Vac supplied from the grid.

Meanwhile, the full-bridge rectification circuit 110 may be implemented as various circuits for rectifying the AC power Vac, including a pair of switching elements connected in a totem pole structure, in addition to the circuits shown in FIGS. 3A and 3B . However, in the following description, it is assumed that the full-bridge rectifier circuit 110 has the structure shown in FIG. 3A for convenience of description.

The decoupling circuit 120 may actively remove noise generated from a diode or a switching element in the full-bridge rectification circuit 110 . That is, the decoupling circuit 120 may perform an active decoupling operation.

For the active decoupling operation, the decoupling circuit 120 may include an inductor and a capacitor, which are passive elements, and a switching element for charging or discharging the two passive elements. It is characterized in that the used switching elements are shared. That is, the first and second switching elements S1 and S2 shown in FIG. 3A may be used for a boosting operation and a decoupling operation at the same time, and each operation will be described later.

When the decoupling circuit 120 is described in detail with reference to FIG. 4A , the decoupling circuit 120 is connected to the output terminal of the full-bridge rectifier circuit 110 and supplies power from the buffer capacitor Cb and the buffer capacitor Cb. The receiving decoupling inductor Ld may be included.

The power output from the full bridge rectifier circuit 110 is stored in the buffer capacitor Cb (1) and supplied to the inductor (2), so that noise in the signal output from the full bridge rectifier circuit 110 can be removed. . This operation may be performed by turning on/off of the first and second switching elements S1 and S2 in the full-bridge rectifier circuit 110 .

More specifically, the current output from the full-bridge rectifier circuit 110 may be provided to the buffer capacitor Cb according to the states of the first and second switching elements S1 and S2, and in this case, the buffer capacitor Cb ) can store the current as a DC voltage (1). In addition, depending on the states of the first and second switching elements S1 and S2, the buffer capacitor Cb and the decoupling inductor Ld may form a closed-circuit, and in this case, the buffer capacitor Cb The power stored in may be provided to the decoupling inductor Ld (2). A method for the controller 130 to control the on/off of the first and second switching elements S1 and S2 for this operation will be described later.

When the structure of the decoupling circuit 120 is described in detail again with reference to FIG. 4A , one end of the buffer capacitor Cb is connected to the positive terminal (+) of the full-bridge rectifier circuit 110, and the decoupling inductor Ld is It may be connected between the other terminal of the buffer capacitor Cb and the negative terminal (-) of the full-bridge rectifier circuit 110 .

According to the states of the first and second switching elements S1 and S2, the AC power supply Vac, the buffer capacitor Cb, and the output circuit 140 may form a closed circuit, and the buffer capacitor Cb is an AC power supply. It can be charged by (Vac) (1). In addition, according to the first and second switching elements S1 and S2, the first and second switching elements S1 and S2, the buffer capacitor Cb, and the decoupling inductor Ld may constitute a closed circuit, and the buffer Power stored in the capacitor Cb may be provided to the decoupling inductor Ld (2).

The decoupling circuit 120 further includes a current limiting diode Dr to form a movement path of power described above, that is, to allow the decoupling inductor Ld to be charged only by the power stored in the buffer capacitor Cb. can do.

4B, the decoupling circuit 120 is connected in series with the decoupling inductor Ld to limit the current flow so that power is supplied only from the buffer capacitor Cb to the decoupling inductor Ld. A current limiting diode Dr. may include

The current limiting diode Dr may prevent the current from being provided to the decoupling inductor Ld when the buffer capacitor Cb is charged by the current output from the full bridge rectifier circuit 110 (1). In addition, when the power charged in the buffer capacitor Cb is supplied to the decoupling inductor Ld (2), the current-limiting diode Dr. reverses the current from the coupling inductor to the buffer capacitor Cb due to overcharging of the inductor. reverse current) can be prevented from flowing.

On the other hand, when the diode limits the current, a reverse voltage may be applied to the diode, and when a reverse voltage exceeding the withstand voltage of the diode is applied, the diode may be damaged. To prevent this, the decoupling circuit 120 may further include a snubber capacitor Cs connected in parallel to the current limiting diode Dr.

The output terminal circuit 140 may be connected to the output terminal of the decoupling circuit 120 . Power by the boosting operation and power by the decoupling operation may be supplied to the output circuit 140 .

More specifically, the controller 130 may control the first and second switching elements S1 and S2 to perform a boosting operation, and thus the boosted power may be provided to the output circuit 140 . In addition, the controller 130 may control the first and second switching elements S1 and S2 to perform a decoupling operation, and accordingly, the power stored in the decoupling inductor Ld may be provided to the output circuit 140 . there is.

Hereinafter, the boosting operation and the decoupling operation will be described in detail by taking the entire circuit of the boost converter 100 shown in FIG. 5 as an example. The full bridge rectification circuit 110 shown in FIG. 5 may follow the example shown in FIG. 3A , and the decoupling circuit 120 may follow the example shown in FIG. 4B .

The output terminal circuit 140 shown in FIG. 5 may include an output terminal capacitor Co connected to the output terminal of the decoupling circuit 120 and a load R receiving an output voltage Vout from the output terminal capacitor Co. The output capacitor Co may store the current provided from the output terminal of the decoupling circuit 120 in the form of an output voltage Vout, and the load R is connected in parallel with the output capacitor Co to obtain an output voltage Vout. can be supplied.

First, the boosting operation will be described.

The controller 130 may control the first and second switching elements S1 and S2 to perform a boosting operation. In other words, the control unit 130 controls the first and second switching elements S1 and S2 to charge power in the boosting inductor Lb or transfer the power charged in the boosting inductor Lb to the output circuit 140 . can be discharged.

Specifically, the controller 130 may turn on at least one of the first and second switching elements S1 and S2 to charge power in the boosting inductor Lb.

The controller 130 may turn-on control of at least one of the first and second switching elements S1 and S2 according to the phase of the input power. More specifically, in a phase in which the magnitude of the input voltage Vin is positive, the turn-on control of the first switching element S1 may be performed. Accordingly, a positive AC current may be provided to the boosting inductor Lb, and the boosting inductor Lb may be charged by the corresponding current. On the other hand, in a phase in which the magnitude of the input voltage Vin is negative, the turn-on control of the second switching element S2 may be performed. Accordingly, the negative AC current may be inverted and provided to the boosting inductor Lb, and the boosting inductor Lb may be charged by the corresponding current.

For this operation, the boost converter 100 of the present invention may further include a voltage sensor 150 connected to an output terminal of the AC power Vac. The voltage sensor 150 may measure the input voltage Vin and provide it to the controller 130 , and the controller 130 controls the first and second switching elements S1 based on the magnitude and phase of the input voltage Vin. , S2) can be controlled.

Subsequently, the controller 130 may supply the power charged in the boosting inductor Lb to the output circuit 140 by turning off the first and second switching elements S1 and S2 .

When the first and second switching elements S1 and S2 are turned off, the AC power Vac, the boosting inductor Lb, and the output terminal circuit 140 may form a closed circuit. Accordingly, not only the power output from the AC power source Vac may be provided to the output terminal circuit 140 , but also the power charged in the boosting inductor Lb may be supplied.

That is, the control unit 130 turns on at least one of the first and second switching elements S1 and S2 to charge power in the boosting inductor Lb, and then the first and second switching elements S1 and S2. A boosting operation may be performed by controlling all of the s to be turned off to discharge the power charged in the boosting inductor Lb to the output circuit 140 .

Next, the decoupling operation will be described.

The controller 130 may control the first and second switching elements S1 and S2 to charge power in the buffer capacitor Cb or supply the power charged in the buffer capacitor Cb to the decoupling inductor Ld. . Through this, noise of the AC component generated in the AC power source Vac and the full-bridge rectifier circuit 110 may be removed.

This decoupling operation may be performed by controlling the first and second switching elements S1 and S2 used for the above-described boosting operation. In other words, the decoupling operation may be performed together with the above-described boosting operation.

Hereinafter, for convenience of explanation, signals output from the controller 130 to control on/off of the first and second switching elements S1 and S2 are respectively applied to the first and second switching control signals Q1 and Q2. to be referred to as In addition, the current flowing through the boosting inductor Lb is referred to as the boosting current im1, the current flowing through the decoupling inductor Ld is referred to as the decoupling current im2, and the voltage applied to the buffer capacitor Cb is referred to as the buffer voltage Vb. do.

Referring to FIG. 6 , the controller 130 may generate first and second switching control signals Q1 and Q2 according to the internally generated timing signal Ts. Specifically, the controller 130 compares the magnitude of the timing signal Ts with the plurality of reference magnitudes (T _max *d _DS1 , T _max *d _DS2 ) to control the first and second switching control signals Q1 and Q2. The reference size may be preset according to the on-duty d _DS1 of the first switching element S1 and the on-duty d _DS2 of the second switching element S2 .

Meanwhile, the waveform diagram shown in FIG. 6 is illustrated on the assumption that the input voltage Vin has a positive value. Accordingly, when the input voltage Vin is negative, the first switching control signal Q1 may be applied to the second switching device S2, and the second switching control signal Q2 may be applied to the first switching device S1. may be authorized for

In one example, when power is charged in the buffer capacitor Cb, the controller 130 turns on the first and second switching elements S1 and S2 to decouple the power charged in the buffer capacitor Cb. It can be supplied to the inductor (Ld).

Referring back to FIG. 6 , in mode 1 , the controller 130 may output first and second switching control signals Q1 and Q2 having a high value. Accordingly, the buffer voltage Vb may decrease and the decoupling current im2 may increase.

Specifically with reference to FIG. 7A, since the first and second switching elements S1 and S2 are turned on in mode 1, the AC current output from the AC power source Vac can flow in the boosting inductor Lb and , the boosting current im1 may increase accordingly.

In addition, since the first and second switching elements S1 and S2 are turned on, the buffer capacitor Cb and the decoupling inductor Ld may form a closed circuit, and the power charged in the buffer capacitor Cb is the decoupling inductor. (Ld) may be provided. Accordingly, the buffer voltage Vb may decrease and the decoupling current im2 may increase.

In another example, when power is charged in the decoupling inductor Ld, the controller 130 turns off at least one of the first and second switching elements S1 and S2 to turn off the charge in the decoupling inductor Ld. Power may be supplied to the output terminal circuit 140 .

Referring back to FIG. 6 , in mode 2 and/or mode 3, the controller 130 may turn-off control at least one of the first and second switching elements S1 and S2. More specifically, in mode 2 , the controller 130 may output the first switching control signal Q1 having a high value and may output the second switching control signal Q2 having a low value. In addition, the controller 130 may output the first and second switching control signals Q1 and Q2 having a low value in mode 3 . Accordingly, the decoupling current im2 may decrease and the output voltage Vout may increase.

First, in detail with reference to FIG. 7B , when the first switching element S1 is turned on and the second switching element S2 is turned off in mode 2, the AC output from the AC power source Vac A current may flow in the boosting inductor Lb, and accordingly, the boosting current im1 may increase.

In addition, since the second switching element S2 is turned off, current flow may not occur between the buffer capacitor Cb and the decoupling inductor Ld. However, regardless of the state of the first and second switching elements S1 and S2 , the decoupling inductor Ld and the output terminal circuit 140 may form a closed circuit, and the power charged in the decoupling inductor Ld is applied to the output terminal It may be provided in the circuit 140 . Accordingly, the decoupling current im2 may decrease.

Next, as described in detail with reference to FIG. 7C , in mode 3, since both the first and second switching elements S1 and S2 are turned off, as described above in the boosting operation, the AC power supply (Vac) and the boosting inductor (Lb), the output circuit 140 may form a closed circuit. Accordingly, the power charged in the boosting inductor Lb may be supplied to the output circuit 140 , and accordingly, the boosting current im1 may decrease.

Meanwhile, regardless of the state of the first and second switching elements S1 and S2 , the decoupling inductor Ld and the output terminal circuit 140 may form a closed circuit, and the power charged in the decoupling inductor Ld is applied to the output terminal. It may be provided in the circuit 140 . Accordingly, the decoupling current im2 may decrease.

Meanwhile, FIG. 7B shows that the first switching element S1 is turned on and the second switching element S2 is turned off as the input voltage Vin has a positive value, but the input voltage ( When Vin) has a negative value, the first switching element S1 may be controlled to be turned off and the second switching element S2 may be controlled to be turned on.

In another example, the control unit 130 may turn off the first and second switching elements S1 and S2 to charge power in the buffer capacitor Cb.

Referring back to FIG. 6 , in mode 3 , the controller 130 may output the first and second switching control signals Q1 and Q2 having a low value. Accordingly, the buffer voltage Vb may increase.

7c, since the first and second switching elements S1 and S2 are turned off in mode 3, the AC power supply Vac, the boosting inductor Lb, the buffer capacitor Cb, and the output terminal The circuit 140 may form a closed circuit. Accordingly, the power output from the AC power source Vac and the power charged in the boosting inductor Lb may be supplied to the output terminal circuit 140 , and accordingly, the boosting current im1 may decrease.

Meanwhile, in mode 3, since the buffer capacitor Cb is located on the movement path of power, a voltage may be charged in the buffer capacitor Cb, and accordingly, the buffer voltage Vb may increase.

Meanwhile, in the aforementioned modes 1 to 3, the load R may be supplied with the output voltage Vout stored in the output terminal capacitor Co and consumed. Accordingly, in mode 1 in which power is not supplied to the output capacitor Co, the output voltage Vout may decrease due to power consumption of the load R. On the other hand, in mode 2 and mode 3 in which power is supplied to the output capacitor Co, the output voltage Vout may increase or decrease or exhibit a low increase rate.

The controller 130 may perform the decoupling operation together with the boosting operation by controlling the first and second switching elements S1 and S2 so that the above-described operations of mode 1 to mode 3 are sequentially performed. In other words, the controller 130 may perform the decoupling operation together with the boosting operation by repeating charging and discharging of the buffer capacitor Cb and the decoupling inductor Ld.

Meanwhile, the controller 130 may adjust the buffer voltage Vb by adjusting the operation time of mode 1 and/or mode 2 .

Referring back to FIG. 6 , in the charging period Tc, the operation time of mode 1 may be short and the operation time of mode 2 may be long. As described above, when the operations of mode 1 to mode 3 are sequentially performed, as the operation time of mode 1 is shorter, the amount of power discharged from the buffer capacitor Cb may be small. Meanwhile, as the operation time of mode 2 increases, the amount of power to be provided to the buffer capacitor Cb, that is, the amount of power stored in the boosting inductor Lb, may increase. Accordingly, in the charging period Tc in which the operation time of mode 1 is short and the operation time of mode 2 is long, the buffer voltage Vb may increase as a result.

On the other hand, in the discharge period Td, the operation time of mode 1 may be long and the operation time of mode 2 may be short. Similarly, when the operations of mode 1 to mode 3 are sequentially performed, the longer the operation time of mode 1 is, the greater the amount of power discharged from the buffer capacitor Cb. Meanwhile, as the operation time of mode 2 is shorter, the amount of power to be provided to the buffer capacitor Cb, that is, the amount of power stored in the boosting inductor Lb, may decrease. Accordingly, in the discharge period Td, the buffer voltage Vb may decrease as a result.

As shown in FIG. 6 , the operating times of mode 1 and mode 2 may be determined according to the on-duties d _DS1 and d _DS2 of the first and second switching elements S1 and S2 . Accordingly, the controller 130 compares the timing signal Ts with reference sizes determined by the on-duties d _DS1 and d _DS2 of the first and second switching elements S1 and S2, and compares the first and second 2 By outputting the switching signals Q1 and Q2, the operation time of mode 1 and mode 2 can be adjusted.

The controller 130 may continuously increase the buffer voltage Vb by repeatedly outputting the first and second switching signals Q1 and Q2 corresponding to the charging period Tc, and may continuously increase the buffer voltage Vb corresponding to the discharging period Td. By repeatedly outputting the first and second switching signals Q1 and Q2, the buffer voltage Vb may be continuously decreased.

The controller 130 may adjust the charging period Tc and the discharging period Tc so that a constant output voltage Vout from which the AC component is removed is provided to the load R.

As described above, the boost converter 100 of the present invention can not only perform the boosting operation that the conventional AC-DC converter can perform, but also perform an active decoupling operation so that the AC component to the load R is removed. It can provide a stable DC voltage.

Accordingly, according to the present invention, the electrolytic capacitor for the passive decoupling operation may be replaced with the film capacitor. That is, according to the present invention, the output terminal capacitor (Co) providing a voltage to the load (R) can be implemented as a film capacitor.

As described above, in the present invention, the noise of the AC component that can be supplied to the load R without a separate switching element for the decoupling operation is reduced by sharing the switching element used for the boosting operation and the switching element used for the decoupling operation. can be actively blocked.

In addition, in the present invention, by replacing the output capacitor (Co) for supplying voltage to the load (R) from the electrolytic capacitor to the film capacitor, it is possible to miniaturize the boost converter 100, improve the power conversion efficiency, and lifespan can increase

As described above, the present invention has been described with reference to the illustrated drawings, but the present invention is not limited by the embodiments and drawings disclosed in this specification, and various methods can be obtained by those skilled in the art within the scope of the technical spirit of the present invention. It is obvious that variations can be made. In addition, although the effects according to the configuration of the present invention have not been explicitly described and described while describing the embodiments of the present invention, it is natural that the effects predictable by the configuration should also be recognized.

Claims (12)

a full-bridge rectifying circuit for rectifying AC power, including first and second switching elements connected to at least one leg;
a decoupling circuit connected to an output terminal of the full-bridge rectification circuit, the decoupling circuit including a buffer capacitor and a decoupling inductor receiving power from the buffer capacitor;
a control unit controlling the first and second switching elements to charge power to the buffer capacitor or to supply power charged in the buffer capacitor to the decoupling inductor; and
an output circuit connected to the output terminal of the decoupling circuit to receive power from the decoupling inductor;
The decoupling circuit is
a current limiting diode connected in series to the decoupling inductor to limit current flow so that power is supplied from the buffer capacitor to the decoupling inductor, and a snubber capacitor connected in parallel to the current limiting diode;
the current limiting diode is disposed between the buffer capacitor and the decoupling inductor;
The control unit is
When power is charged in the buffer capacitor, a first mode in which the first and second switching elements are turned on to supply the power charged in the buffer capacitor to the decoupling inductor, the decoupling inductor is charged with power a second mode of supplying power charged in the decoupling inductor to the output circuit by turning-off control of at least one of the first and second switching elements, and turn-off control of the first and second switching elements to control the first and second switching elements so that a third mode of charging power to the buffer capacitor is sequentially performed
boost converter.
According to claim 1,
The full bridge rectification circuit is connected to the grid to rectify the AC power supplied from the grid.
boost converter.
According to claim 1,
The full-bridge rectification circuit includes a boosting inductor having one end connected to the grid, a first leg connected to the other end of the boosting inductor, and a second leg connected in parallel to the first leg,
First and second diodes are connected to the first leg, and the first and second switching elements are connected to the second leg
boost converter.
The method of claim 1,
One end of the buffer capacitor is connected to the positive terminal of the full-bridge rectifier circuit,
The decoupling inductor is connected between the other end of the buffer capacitor and the negative terminal of the full-bridge rectifier circuit.
boost converter.
delete delete According to claim 1,
The output circuit is
an output capacitor connected to the output terminal of the decoupling circuit;
and a load receiving the output voltage from the output capacitor.
boost converter.
8. The method of claim 7,
The output capacitor is a film capacitor.
boost converter.
According to claim 1,
The control unit turns on at least one of the first and second switching elements to charge power in the boosting inductor in the full-bridge rectifier circuit.
boost converter.
delete delete delete

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