KR20210056696A - Boost converter with decoupling operation - Google Patents

Abstract

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

Description

Boost converter performing decoupling operation {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 in an ON state or an OFF state to intercept the current, the current or voltage in the converter rapidly changes, which generates noise. In order to prevent the noise generated in this way 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 a conventional boost converter will be described with reference to FIG. 1.

When the power switching element (S) is turned on and controlled, the AC current output from the AC voltage source (Vac) is converted into a DC current through a plurality of diodes (D1, D2, D3, 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.

In this case, noise is generated by the switching operation in the power switching element S, and in order to prevent such noise from being supplied to the load, the conventional boost converter includes a decoupling capacitor C connected in parallel with the load.

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

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. Film capacitors have a relatively small capacity compared to electrolytic capacitors, so that the passive decoupling operation described above is not It can't be done properly.

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 a capacitor.

An object of the present invention is to provide a boost converter that shares a switching element used for a boosting operation and a switching element used for a decoupling operation.

In addition, an object of the present invention is to provide a boost converter capable of replacing an output capacitor 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 that are not mentioned can be understood by the following description, and will be more clearly understood by examples of the present invention. In addition, it will be easily understood that the objects and advantages of the present invention can be realized by the means shown in the claims and combinations thereof.

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 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 that performs an active decoupling operation inside a general AC-DC converter, so that an output capacitor that supplies a voltage to a load can be replaced with a film capacitor from an electrolytic capacitor.

In the present invention, by sharing the switching element used for the boosting operation and the switching element used for the decoupling operation, noise of an AC component that can be supplied to the load can be actively blocked without a separate switching element for the decoupling operation.

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

In addition to the above-described effects, specific effects of the present invention will be described together with explanation of specific matters for carrying out the present invention.

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

The above-described objects, features, and advantages will be described later in detail with reference to the accompanying drawings, and accordingly, a person 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 subject matter of the present invention, a detailed description will be omitted. Hereinafter, preferred embodiments of 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 elements.

In the present specification, the first, second, etc. are used to describe various elements, but these elements are of course not limited by these terms. These terms are only used to distinguish one component from another component, and unless otherwise stated, the first component may be the second component.

In addition, in the present specification, when a component is described as being "connected", "coupled" or "connected" to another component, the components may be directly connected or connected to each other, but different components between each component It is to be understood that elements may be “interposed”, or each element may be “connected”, “coupled” or “connected” through other elements.

In addition, a singular expression used in the present specification includes a plurality of expressions unless the context clearly indicates otherwise. In the present application, terms such as “consisting of” or “comprising” should not be construed as necessarily including all of the various elements or various steps described in the specification, and some of the elements or some steps It may not be included, or it should be interpreted that it may further include additional components or steps.

In addition, in the present specification, when referred to as "A and/or B", it means A, B or A and B unless otherwise specified, and when referred to as "C to D", it is a special opposite Unless otherwise stated, it means that it is more than C and less than or equal to D.

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 showing the configuration of a boost converter according to an embodiment of the present invention.

3A and 3B are diagrams showing exemplary circuits of the full bridge rectifier circuit shown in FIG. 2, respectively. 4A and 4B are diagrams each showing an exemplary circuit 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 illustrating a decoupling operation through charging and discharging of a buffer capacitor and a decoupling inductor, and FIGS. 7A to 7C are diagrams illustrating current flows for each mode shown in FIG. 6.

2, the boost converter 100 according to an embodiment of the present invention includes a full-bridge rectifier circuit 110, a decoupling circuit 120, a control unit 130, and an output terminal circuit ( 140). 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. .

Meanwhile, the controller 130 to be described later includes application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), and processors. ), controllers, micro controllers, and microprocessors.

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, thereby rectifying the AC power Vac.

Referring to FIG. 3A, a structure of the full-bridge rectifier circuit 110 according to an example will be described. The full-bridge rectifier circuit 110 includes a boosting inductor Lb having one end connected to the system, and 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 in a pair to the first leg 110a, and the first and second switching elements S1 and S2 may be connected to the second leg 110b. Can be finalized in a pair.

Basically, the positive AC current supplied from the AC power source (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 source (Vac) is reduced. 2 As the diode D2 and the first switching element S1 are inverted and provided to the output terminal, the AC power Vac may be full-wave rectification. To this end, the controller 130 may provide a switching control signal synchronized to the phase of the AC power Vac to the first and second switching elements S1 and S2.

Referring to FIG. 3B, a structure of the full bridge rectifier circuit 110 according to another example will be described. As described in FIG. 3A, the full bridge rectifier circuit 110 includes a boosting inductor Lb, a first leg 110a, and It may include a second leg (110b). In this case, a pair of first and second diodes D1 and D2 may be formed and connected to the first leg 110a. The third and fourth switching elements S3 and S4 may be connected to the second leg 110b in a pair.

Basically, the positive AC supplied from the AC power 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 Vac is the second and second. 3 As the switching elements S2 and S3 are inverted and provided to the output terminal, the AC power Vac can be full-wave rectified. To this end, the controller 130 may provide each switching control signal synchronized to the phase of the AC power Vac to the first to fourth switching elements S1, S2, S3, and S4.

During this rectification process, a boosting operation may be performed. More specifically, during the rectification process, the boosting inductor Lb may charge the power output from the AC power 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 any AC power source (Vac). For example, the full bridge rectification circuit 110 may be connected to a system (eg, commercial AC power) and rectify the AC power Vac supplied from the system.

Meanwhile, the full bridge rectification circuit 110 may be implemented as various circuits for rectifying 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, for convenience of description, it is assumed that the full bridge rectifier circuit 110 has the structure shown in FIG. 3A.

The decoupling circuit 120 may actively remove noise generated from a diode or a switching element in the full bridge rectifier 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 a passive element, an inductor and a capacitor, 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 can be used for a boosting operation and a decoupling operation, 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. It may include a receiving decoupling inductor Ld.

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 and off 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 corresponding current as a DC voltage (1). In addition, the buffer capacitor Cb and the decoupling inductor Ld may form a closed-circuit according to the states of the first and second switching elements S1 and S2, and at this time, the buffer capacitor Cb The power stored in may be provided to the decoupling inductor Ld (2). A method of controlling the on/off of the first and second switching elements S1 and S2 by the control unit 130 for this operation will be described later.

Referring again to FIG. 4A, the structure of the decoupling circuit 120 will be described in detail, 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 end of the buffer capacitor Cb and the negative terminal (-) of the full bridge rectifier circuit 110.

Depending on the state of the first and second switching elements S1 and S2, the AC power supply Vac, the buffer capacitor Cb, and the output terminal circuit 140 may form a closed circuit, and the buffer capacitor Cb is an AC power supply. 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 form 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, in order to form the movement path of the power described above, that is, so that the decoupling inductor Ld is charged only by the power stored in the buffer capacitor Cb. can do.

4B, the decoupling circuit 120 is connected in series to 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. Can include.

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

Meanwhile, 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 a boosting operation and power by a decoupling operation may be supplied to the output terminal circuit 140.

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

Hereinafter, a boosting operation and a 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 illustrated 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) can 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 terminal capacitor (Co) to output the output voltage (Vout). Can be supplied.

First, the boosting operation will be described.

The controller 130 may perform a boosting operation by controlling the first and second switching elements S1 and S2. In other words, the controller 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 terminal circuit 140. It can be discharged.

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

The controller 130 may turn on at least one of the first and second switching elements S1 and S2 according to the phase of the input power. More specifically, the first switching element S1 may be turned on in a phase in which the magnitude of the input voltage Vin is positive. 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 second switching element S2 may be turned on. 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 the 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 may measure the first and second switching elements S1 based on the magnitude and phase of the input voltage Vin. , S2) can be controlled.

Subsequently, the control unit 130 may turn off the first and second switching elements S1 and S2 to supply power charged in the boosting inductor Lb to the output terminal circuit 140.

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 Vac is provided to the output terminal circuit 140, but the power charged in the boosting inductor Lb may also 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. The boosting operation may be performed by controlling all of the signals to be turned off and discharging the power charged in the boosting inductor Lb to the output terminal 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 from the AC power 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 in 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 description, signals output from the control unit 130 to control on/off of the first and second switching elements S1 and S2 are respectively referred to as first and second switching control signals Q1 and Q2. It should 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 a timing signal Ts generated therein. Specifically, the control unit 130 compares the size of the timing signal Ts and a plurality of reference sizes (T _max *d _DS1 , T _max *d _DS2 ) to compare the first and second switching control signals Q1 and Q2. The reference size may be set in advance 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 illustrated in FIG. 6 is illustrated assuming 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 element S2, and the second switching control signal Q2 may be applied to the first switching element S1. Can be applied to.

In one example, when power is charged in the buffer capacitor Cb, the controller 130 controls the first and second switching elements S1 and S2 to turn on 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 high first and second switching control signals Q1 and Q2. Accordingly, the buffer voltage Vb may decrease and the decoupling current im2 may increase.

Specifically, referring 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 Vac may flow through the boosting inductor Lb. As a result, the boosting current im1 may increase.

In addition, since the first and second switching elements S1 and S2 are turned on, the buffer capacitor Cb and the decoupling inductor Ld can form a closed circuit, and the power charged in the buffer capacitor Cb is the decoupling inductor. (Ld) can 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 control unit 130 controls at least one of the first and second switching elements S1 and S2 to turn off to be charged 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 at least one of the first and second switching elements S1 and S2. More specifically, in mode 2, the controller 130 may output a high value first switching control signal Q1 and a low value second switching control signal Q2. In addition, the controller 130 may output low-value first and second switching control signals Q1 and Q2 in mode 3. Accordingly, the decoupling current im2 may decrease and the output voltage Vout may increase.

First, referring to FIG. 7B in detail, 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 Vac Current may flow through the boosting inductor Lb, and accordingly, the boosting current im1 may increase.

Also, since the second switching element S2 is in a turned-off state, no current flow may occur between the buffer capacitor Cb and the decoupling inductor Ld. However, regardless of the states 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 the output terminal. It may be provided in the circuit 140. Accordingly, the decoupling current im2 may decrease.

Next, referring to FIG. 7C in detail, since both the first and second switching elements S1 and S2 are turned off in mode 3, the AC power supply Vac and the boosting inductor are as described in the boosting operation. (Lb), the output terminal circuit 140 may form a closed circuit. Accordingly, 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, regardless of the states 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 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. When Vin) has a negative value, the first switching element S1 may be turned off and the second switching element S2 may be turned on.

In another example, the controller 130 may charge power in the buffer capacitor Cb by turning off the first and second switching elements S1 and S2.

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

Referring to FIG. 7C, since the first and second switching elements S1 and S2 are turned off in mode 3, AC power Vac, boosting inductor Lb, buffer capacitor Cb, and output terminal The circuit 140 may form a closed circuit. Accordingly, the power output from the AC power 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 above-described modes 1 to 3, the load R may consume and receive the output voltage Vout stored in the output terminal capacitor Co. 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 modes 2 and 3 in which power is supplied to the output capacitor Co, the output voltage Vout may increase or decrease or may exhibit a low increase rate.

The controller 130 may perform a decoupling operation together with a boosting operation by controlling the first and second switching elements S1 and S2 to sequentially perform the operations of the modes 1 to 3 described above. In other words, the controller 130 may perform a decoupling operation together with a 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 section 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 smaller. 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 where 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. Likewise, when the operations of mode 1 to mode 3 are sequentially performed, the amount of power discharged from the buffer capacitor Cb may increase as the operation time of mode 1 increases. Meanwhile, as the operation time of mode 2 decreases, 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 operation time of mode 1 and mode 2 may be determined according to _{on-duties d DS1} and d _{DS2 of the first and second switching elements S1 and S2.} Accordingly, the control unit 130 compares the timing signal Ts with the reference sizes determined by _{the on-duties d DS1} and d _{DS2 of the first and second switching elements S1 and S2,} 2 By outputting the switching signals Q1 and Q2, the operating 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, or The buffer voltage Vb may be continuously decreased by repeatedly outputting the first and second switching signals Q1 and Q2.

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

As described above, the boost converter 100 of the present invention not only performs a boosting operation that can be performed by a conventional AC-DC converter, but also performs an active decoupling operation, thereby removing an AC component from the load R. It can provide a stable DC voltage.

Accordingly, according to the present invention, an electrolytic capacitor for a passive decoupling operation can be replaced with a 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, the present invention shares the switching element used for the boosting operation and the switching element used for the decoupling operation, thereby reducing the noise of the AC component that can be supplied to the load R without a separate switching element for the decoupling operation. Can be actively blocked.

In addition, the present invention can reduce the size of the boost converter 100 by replacing the output capacitor (Co) supplying voltage to the load (R) with a film capacitor from the electrolytic capacitor, it is possible to improve the power conversion efficiency, and Can increase.

As described above with reference to the drawings illustrated for the present invention, the present invention is not limited by the embodiments and drawings disclosed in the present specification, and various by a person skilled in the art within the scope of the technical idea of the present invention. It is obvious that transformations can be made. In addition, even if not explicitly described and described the effects of the configuration of the present invention while describing the embodiments of the present invention, it is natural that the predictable effects of the configuration should also be recognized.

Claims (12)

A full-bridge rectifier 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 rectifier circuit and including a buffer capacitor and a decoupling inductor supplied with power from the buffer capacitor;
A controller configured to control the first and second switching elements to charge power to the buffer capacitor or to supply power charged to the buffer capacitor to the decoupling inductor; And
And an output terminal circuit connected to the output terminal of the decoupling circuit to receive power from the decoupling inductor.
Boost converter.
The method of claim 1,
The full bridge rectifier circuit is connected to the grid to rectify AC power supplied from the grid.
Boost converter.
The method of claim 1,
The full bridge rectification circuit includes a boosting inductor having one end connected to the system, 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 a 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.
The method of claim 1,
The decoupling circuit includes a current limiting diode connected in series to the decoupling inductor to limit current flow so that power is supplied only from the buffer capacitor to the decoupling inductor.
Boost converter.
The method of claim 5,
The decoupling circuit includes a snubber capacitor connected in parallel to the current limiting diode.
Boost converter.
The method of claim 1,
The output circuit is
An output terminal capacitor connected to the output terminal of the decoupling circuit,
Including a load receiving an output voltage from the output terminal capacitor
Boost converter.
The method of claim 7,
The output terminal capacitor is a film capacitor
Boost converter.
The method of claim 1,
The control unit controls at least one of the first and second switching elements to be turned on to charge power to the boosting inductor in the full bridge rectifier circuit.
Boost converter.
The method of claim 1,
The control unit controls the first and second switching elements to be turned on to supply power charged in the buffer capacitor to the decoupling inductor.
Boost converter.
The method of claim 1,
The control unit controls at least one of the first and second switching elements to turn off to supply power charged in the decoupling inductor to the output terminal circuit.
Boost converter.
The method of claim 1,
The control unit is configured to charge power to the buffer capacitor by turning off the first and second switching elements.
Boost converter.

Images