Bridgeless power factor correction converter

Abstract

A bridgeless power factor improvement converter according to one embodiment of the present application includes a power input unit for receiving power, first and second rectifying units for rectifying the received power, and a power factor improvement switching unit connected to the first and second rectifying units and improving a power factor according to on / off operation. The second rectifying unit includes a second upper switch and a second lower switch, wherein the second upper switch is driven by a driving power source connected to the power factor improvement switching unit.

Description

Technical Field

[0001] The present invention relates to a bridgeless power factor improvement converter, and more particularly, to a bridgeless power factor improvement converter driven by a small drive power supply. Background Technology

[0002] In the case of converters that convert input power, the power factor is reduced due to phase mismatch between voltage and current caused by rectifier diodes, capacitors, etc. in the converter's circuitry. To solve this problem, the power factor can be improved by using devices such as capacitors, and more recently, the waveform of the current has been altered while controlling the current through the converter between the AC power supply and the load.

[0003] In various topologies, power factor can be corrected by using a full-bridge control current to control the magnitude and phase. PFC topologies can be applied in various ways depending on the use and purpose, such as buck converters and boost converters. However, boost converters for power factor improvement have limitations in ensuring high efficiency. Therefore, bridgeless power factor improvement converters that do not require bridge diodes are used. However, since bridgeless power factor improvement converters have switches not located on their underside, the problem is that the switch drive unit of the boost converter used for power factor improvement cannot be used as is. Summary of the Invention

[0004] Technical issues

[0005] The technical problem to be solved by the present invention is to provide a bridgeless power factor improvement converter driven by a small drive power supply.

[0006] Technical solution

[0007] To address the above technical problems, a bridgeless power factor correction converter according to an embodiment of the present invention includes: a power input unit for receiving power; a first rectifier unit and a second rectifier unit for rectifying the received power; and a power factor correction switching unit connected to the first rectifier unit and the second rectifier unit and improving the power factor according to an on / off operation, wherein the second rectifier unit includes a second upper switch and a second lower switch, and wherein the second upper switch is driven by a drive power supply connected to the power factor correction switching unit.

[0008] In addition, it includes: a first switch driving unit for driving a power factor improvement switch unit; a second switch driving unit for driving a second upper switch; and a third switch driving unit for driving a second lower switch, wherein the second switch driving unit can receive power from the drive power supply of the first switch driving unit.

[0009] In addition, the second switch driving unit may include: a control unit for controlling the gate voltage of the second upper switch; and a bootstrap circuit unit for receiving drive power from the drive power supply of the first switch driving unit and supplying power to the control unit.

[0010] In addition, the bootstrap circuit unit may include a capacitor and a diode connected to the drive power supply of the first switch drive unit.

[0011] Furthermore, one end of the capacitor in the bootstrap circuit unit is connected to the control unit, and the other end is connected to the source of the MOSFET switch, which is the second upper switch; and the anode of the diode in the bootstrap circuit unit is connected to the drive power supply of the first switch drive unit, and the cathode can be connected to the node between the capacitor and the control unit.

[0012] In addition, the power factor improvement switching unit may include two MOSFET switches whose sources are connected to each other.

[0013] In addition, the sources of the two MOSFET switches of the power factor improvement switching unit can be connected to the drive power supply of the power factor improvement switching unit.

[0014] In addition, the first rectifier unit includes an upper diode and a lower diode, wherein one end of the power factor improvement switch unit is connected to the node between the upper diode and the lower diode, and the other end can be connected to the node between the second upper switch and the second lower switch.

[0015] In addition, the power input unit can receive either AC or DC power.

[0016] In addition, the power input unit may include an inductor.

[0017] In addition, an output capacitor connected to the output terminals of the first rectifier unit and the second rectifier unit may be included.

[0018] To address the above technical problems, a bridgeless power factor correction converter according to another embodiment of the present invention includes: a power input unit for receiving power; a first rectifier unit and a second rectifier unit for rectifying the input power; and a power factor correction switching unit connected to the first rectifier unit and the second rectifier unit and improving the power factor according to an on / off operation, wherein the first rectifier unit includes a first upper switch and a first lower switch, wherein the second rectifier unit includes a second upper switch and a second lower switch, and wherein the first upper switch and the second upper switch are connected to and driven by the power factor correction switching unit.

[0019] In addition, the first switch can be driven by a power supply connected to the second switch.

[0020] To address the above technical problems, a bridgeless power factor correction converter according to another embodiment of the present invention includes: a power input unit for receiving power; a first rectifier unit and a second rectifier unit for rectifying the input power; and a power factor correction switching unit connected to the first rectifier unit and the second rectifier unit and improving the power factor according to an on / off operation, wherein the first rectifier unit includes a first upper switch and a first lower switch, and wherein the first upper switch is driven by a drive power supply connected to the power factor correction switching unit.

[0021] Beneficial effects

[0022] According to embodiments of the present invention, the switches of the bridgeless power factor correction converter can be driven using a small amount of drive power. Furthermore, the rectifier unit can be driven using the line frequency or even when DC power is applied. Additionally, the drive circuit can be implemented using capacitors with small capacitance. Attached Figure Description

[0023] Figure 1 This is a block diagram of a bridgeless power factor improvement converter according to an embodiment of the present invention.

[0024] Figures 2 to 9 A comparative example of a bridgeless power factor improvement converter according to an embodiment of the present invention is shown.

[0025] Figure 10 This is an exemplary circuit diagram of a bridgeless power factor improvement converter according to an embodiment of the present invention.

[0026] Figure 11 and Figure 12 This is a view used to illustrate a power factor improvement converter according to an embodiment of the present invention.

[0027] Figure 13 This is a block diagram of a bridgeless power factor improvement converter according to another embodiment of the present invention.

[0028] Figure 14 This is an exemplary circuit diagram of a bridgeless power factor improvement converter according to another embodiment of the present invention.

[0029] Figure 15 This is a block diagram of a bridgeless power factor improvement converter according to another embodiment of the present invention.

[0030] Figure 16 This is an exemplary circuit diagram of a bridgeless power factor improvement converter according to another embodiment of the present invention. Detailed Implementation

[0031] In the following, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0032] However, the technical concept of the present invention is not limited to the embodiments described, but can be implemented in various forms, and within the scope of the technical concept of the present invention, one or more constituent elements can be selectively combined or substituted between embodiments.

[0033] Furthermore, unless explicitly defined and described, the terms (including technical and scientific terms) used in the embodiments of the present invention may be interpreted as meanings that can be commonly understood by those skilled in the art, and commonly used terms, such as those defined in dictionaries, may be interpreted in light of the contextual meaning of the relevant art.

[0034] Furthermore, the terminology used in this specification is for describing embodiments and is not intended to limit the invention.

[0035] In this specification, unless explicitly stated in the phrase, the singular form may include the plural form, and when described as “at least one (or more than one) of A, B and C”, it may include one or more of all combinations that can be combined with A, B and C.

[0036] Furthermore, when describing components of embodiments of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are intended only to distinguish components from other components, and they do not limit the nature, order, or sequence of the components.

[0037] Furthermore, when a component is described as being “connected,” “coupled,” or “interconnected” to another component, the component is not only directly connected, coupled, or interconnected to the other component, but may also include situations where the “connection,” “coupling,” or “interconnection” is made due to another component between the other components.

[0038] Furthermore, when described as being formed or arranged "above" or "below" in relation to each component, "above" or "below" means not only the case where two components are in direct contact, but also the case where one or more other components are formed or arranged between the two components. Additionally, when expressed as "above" or "below," it can include meanings based on a component that include not only the upward direction but also the downward direction.

[0039] Figure 1 This is a block diagram of a bridgeless power factor improvement converter according to an embodiment of the present invention.

[0040] According to an embodiment of the present invention, a bridgeless power factor improvement converter 100 includes a power input unit 110, a first rectification unit 120, a second rectification unit 130, and a power factor improvement switching unit 140, and may further include a switch driving unit (not shown) and a drive power supply 150 for driving the switches included in the bridgeless power factor improvement converter 100.

[0041] The power input unit 110 receives power. Here, the power input unit 110 can receive AC power or DC power. The input power is rectified by the first rectifier unit 120, the second rectifier unit 130, and the power factor improvement switch unit 140, and the power factor is improved.

[0042] The first rectifier unit 120 rectifies the input power. The first rectifier unit 120 consists of an upper diode and a lower diode, and can rectify the received input power. Alternatively, the first rectifier unit 120 can rectify the received input power using a switch instead of a diode. The upper and lower diodes can be connected in parallel to the power input unit 110.

[0043] The second rectifier unit 130 rectifies the power output from the bridgeless power factor correction converter 100. The second rectifier unit 130 may include a second upper switch and a second lower switch. The second upper switch and the second lower switch may be connected in parallel to the (-) terminal of the power input unit 110. The second upper switch of the second rectifier unit 130 is driven by a drive power supply 150 included in a switch drive unit that drives the power factor correction switch unit 140. When driving each switch, a drive power supply is required to be connected to each of the corresponding switches and to supply power. When driving the second upper switch, the number of drive power supplies used to drive the switches can be reduced by using the drive power supply 150 included in the switch drive unit that drives the power factor correction switch unit 140 together.

[0044] Power factor improvement switching unit 140 is connected to the first rectifier unit 120 and the second rectifier unit 130 to improve the power factor according to on / off operations. One end of the power factor improvement switching unit 140 is connected to the node between the upper and lower diodes of the first rectifier unit 120, and the other end is connected to the node between the second upper switch and the second lower switch of the second rectifier unit 130 to improve the power factor through on / off operations. The specific process of improving the power factor will be described in detail later.

[0045] Figures 2 to 9A comparative example of a bridgeless power factor improvement converter according to an embodiment of the present invention is shown. Although described as a comparative example, the bridgeless power factor improvement converter according to an embodiment of the present invention may naturally include some configurations.

[0046] To improve the power factor, the voltage and current of the input AC circuit must be in phase. To improve the power factor, methods such as... Figure 2 The boost converter shown is an example. Since a negative voltage cannot be applied to the input of the boost converter, a bridge diode is used to rectify the AC voltage. The diodes in the bridge diode change their conduction state according to the AC voltage frequency (50Hz / 60Hz), and the diodes and switches operate at high frequencies (tens of kHz or higher). The number of components in the current conduction path depends on the switch state.

[0047] [Table 1]

[0048] Connect 1 2 Turn off 0 3

[0049] Boost converters have limitations in ensuring high efficiency due to conduction losses occurring in the bridge diodes. Figure 3 This is an example of a bridgeless power factor improvement converter that does not use bridge diodes. Figure 3 The circuit can be equivalently represented as Figure 4 As shown in the diagram, the power input unit is directly connected to the first rectifier unit, the main switch, and the second rectifier unit. When using such a converter, the power factor can be improved when AC power is applied because the current becomes frequency-synchronized with the voltage according to the on / off operation of the main switch. Figure 3 In a bridgeless power factor improvement converter, the number of components located on the current conduction path varies depending on the state of the switch, as follows.

[0050] [Table 2]

[0051] Connect 2 0 Turn off 0 2

[0052] and Figure 2 Compared to boost power factor improvement converters, the number of devices in the current conduction path is reduced, and in particular, an efficiency improvement can be expected due to the reduced number of diodes. However, both diodes remain conducting in the switch-off state. To reduce the number of conducting diodes when the switch is off, such as... Figure 5As shown, a switch can be applied to the second rectifier unit. A MOSFET can be used as the switch. In this case, the operation depending on the switch state is the same as in the case using a diode, as described previously. When the switch is off, the current passes through both a switch and a diode. In this way, by replacing the diode with a MOSFET having a low Rds.on (drain-source resistance in the on-state), an improvement in efficiency can be expected.

[0053] [Table 3]

[0054] Connect 2 0 Turn off 1 1

[0055] To drive the switches included in the converter, a switch driver unit (gate driver), i.e., a switch driver circuit, is required. Since the switches in a boost PFC converter are located on the low side, it has the advantage of being relatively easy to implement the power supply and drive circuitry included in the switch driver unit. On the other hand, because there are switches not located on the low side, i.e., there are switches located on the upper side, bridgeless power factor improvement converters require relatively complex switch driver units. When the switches are applied to the second rectifier unit, they can be used as follows... Figure 6 The various configurations of the switches are shown. That is, the switches can be configured in various ways depending on the location of the inductor and the rectifier unit to which the inductor is connected. Devices such as the first rectifier unit, which switch at high speeds, may generate a relatively large amount of electromagnetic noise. Therefore, as... Figure 6 (B) or Figure 6 As shown in (D), when the first rectifier unit is directly connected to the AC power supply, it may be disadvantageous in terms of electromagnetic noise (EMI). To reduce electromagnetic noise, such as... Figure 6 (A) or Figure 6 As shown in (C), this can be implemented by adding an inductor between the AC power supply and the first rectifier unit. Because Figure 6 (A) and Figure 6 (C) and Figure 6 (B) and Figure 6 (D) Since there are different connection points between the input power and the inductor, the switching on of the second rectifier unit changes according to the polarity of the input power. In other words, this relationship reverses the on / off states of the upper and lower switches of the second rectifier unit.

[0056] A bridgeless PFC converter, including a switch drive unit, can be like... Figure 7The configuration is shown. The two MOSFETs included in the main switch require a switch drive unit referenced to their source terminals, and if the source terminals are set to be in contact with each other (common source), there is an advantage that the two MOSFETs can share a single switch drive unit. In this case, power can be generated by a separate converter. Because the switch drive unit is used as a reference, similar to a boost converter, the lower switch included in the second rectifier unit is easily implemented. In this case, power can be generated by a separate converter or a linear regulator.

[0057] On the other hand, the high-side switch included in the second rectifier unit requires a switch drive unit that references the source terminal of the upper switch. This can then be achieved in various ways to generate electricity.

[0058] First, such as Figure 7 As shown, this can be achieved using a separate converter (auxiliary converter). The converter can use the auxiliary converter to generate auxiliary power. Therefore, it can be achieved by generating another output in the auxiliary converter. However, this has the disadvantage of complicating the auxiliary converter. In addition, a switch driver unit is needed to drive each switch, and three power supplies are needed to drive the control unit of the switch driver unit.

[0059] Or, such as Figure 8 As shown, a bootstrap circuit can be used. A bootstrap circuit can be used to drive a half-bridge switch. The bootstrap circuit utilizes a diode and a capacitor, and generates power by receiving power from another switch driver unit. This reduces the power supply required by the switch driver unit to two. When using the drive power of the lower switch, the bootstrap circuit charges the energy in the capacitor when the lower switch is on, and uses the energy stored in the capacitor when the lower switch is off. Therefore, to maintain the voltage of the capacitor, the lower switch must be turned on periodically. If the second rectifier unit operates synchronously with the line frequency at 50Hz or 60Hz, the capacitor is charged every few milliseconds. Therefore, to maintain a sufficient power level in the capacitor, a disadvantage exists that a large capacitor is required compared to the case of operation at several kHz.

[0060] Bridgeless power factor correction converters (PFDs) are used to receive AC power and generate DC power, but depending on the user's needs, they may require operation even when DC power is being input. In the case of boost PFDs, a bridge diode is used, and the switch is located on the lower side, making converter operation easy even when DC power is applied. However, in the case of bridgeless PFDs, the operation differs depending on the wiring of the DC power. That is, as... Figure 9As shown, the diodes and the second rectifier unit switch, which operate according to the polarity of the DC power supply, vary depending on the connection state of the power input unit, the first rectifier unit, the main switch, and the second rectifier unit.

[0061] like Figure 9 As shown in (A), when the inductor is located between the power input unit and the first rectifier unit, the lower switch of the second rectifier unit is always on when the DC power supply is positive. At this time, since the lower switch uses power generated relative to ground, it can maintain a continuous on-state. Figure 9 As shown in (B), when the DC power supply is negative, the upper switch of the second rectifier unit is always on. To drive the upper switch, a power supply referenced to the source terminal of the corresponding switch is required. At this time, when the bootstrap circuit is used to generate power, it is not charged because the lower switch is not on. Therefore, it is difficult to use the bootstrap circuit to drive the upper switch in this situation. If the bootstrap circuit is used, its use may be limited because it is affected by the on / off state of the lower switch.

[0062] like Figure 9 As shown in (C), with the inductor located between the power input unit and the second rectifier unit, the upper switch of the second rectifier unit is always on when the DC power supply is positive. To drive the upper switch, a power supply referenced to the source terminal of the corresponding switch is required. In this case, when the bootstrap circuit is used to generate power, it is not charged because the lower switch is not on. Therefore, it is difficult to use the bootstrap circuit to drive the upper switch in this situation. If the bootstrap circuit is used, its use may be limited because it is affected by the on / off state of the lower switch. Figure 9 As shown in (D), when the DC power supply is negative, the lower switch of the second rectifier unit is always on. At this time, since the lower switch uses power generated relative to ground, it can maintain a continuous on state.

[0063] In the bridgeless power factor improvement converter 100 according to an embodiment of the present invention, since the second upper switch of the second rectifier unit 130 is connected to the drive power supply 150 included in the switch drive unit for driving the power factor improvement switch unit 140, the implementation of the auxiliary converter for generating auxiliary power is simplified. Furthermore, since the bootstrap circuit receives power from the main switch drive unit and operates independently of the conduction state of the second lower switch of the second rectifier unit 130, it is easy to use the second rectifier unit 130 at line frequency or the bridgeless power factor improvement converter in the case of DC power supply. Moreover, while the bootstrap circuit is configured to receive the drive power supply 150 of the switch drive unit that drives the power factor improvement switch unit 140, it may be affected by the conduction state of the main switch. However, the power factor improvement switch unit 140 does not switch when 1) the bridgeless power factor improvement converter itself is not operating, or 2) the bridgeless power factor improvement converter is unloaded. In this case, since the second rectifier unit 130 does not need to operate, there is no problem.

[0064] Figure 10 This is an exemplary circuit diagram of a bridgeless power factor improvement converter according to an embodiment of the present invention.

[0065] The bridgeless power factor correction converter is configured with a power input unit 110, a first rectifier unit 120, a second rectifier unit 130, and a power factor correction switching unit 140, and includes: a first switch drive unit 171 for driving the power factor correction switching unit 140; a second switch drive unit 172 for driving the second upper switch 131 of the second rectifier unit 130; and a third switch drive unit 173 for driving the second lower switch 132 of the second rectifier unit 130, wherein the second switch drive unit 172 can receive power from the drive power supply 150 of the first switch drive unit 171. The power input unit 110 may include a power supply unit 111 and an inductor 112, and an output capacitor 190 may be connected to an output terminal.

[0066] According to the embodiment, when the power factor improvement switching unit 140 is turned on, energy is stored in the inductor 112 of the power input unit 110, and when the power factor improvement switching unit 140 is not turned on, the diode in the first rectifier unit 120 is turned on and transfers the energy stored in the inductor 112 to the output capacitor 190. At this time, the current of the inductor 112 and the voltage of the output capacitor 190 can be controlled by adjusting the duty cycle of the power factor improvement switching unit 140. The switch drive units 171, 172, and 173 connected to each switch control the on / off state of the corresponding switches 140, 131, and 132 according to the signals input to them.

[0067] The power factor improvement switching unit 140 may include two MOSFET switches whose sources are connected to each other. The first switch driving unit 171 may include: a control unit 181 for controlling the gate voltages of the two MOSFET switches of the power factor improvement switching unit 140; and a drive power supply 150 for supplying power to the control unit 181. Specifically, a drive power supply 150 of the first switch driving unit 171 is connected to the sources of the two MOSFETs of the power factor improvement switching unit 140, and the control unit 181 can simultaneously control the gate voltages of the two MOSFET switches of the power factor improvement switching unit 140.

[0068] The first rectifier unit 120 includes an upper diode and a lower diode. One end of the power factor improvement switch unit 140 is connected to the node between the upper diode and the lower diode, and the other end can be connected to the node between the second upper switch 131 and the second lower switch 132.

[0069] The second switch driving unit 172 may be configured with: a control unit 182 for controlling the gate voltage of the second upper switch 131; and a bootstrap circuit unit 160 for receiving power from the drive power supply 150 of the first switch driving unit 171 and supplying power to the control unit 182.

[0070] The bootstrap circuit unit 160 may be configured with a capacitor and a diode connected to the drive power supply 150 of the first switch drive unit 171. One end of the capacitor in the bootstrap circuit unit 160 is connected to the control unit 182, and the other end is connected to the source of a MOSFET switch, which is the second upper switch 131; the anode of the diode in the bootstrap circuit unit 160 is connected to the drive power supply 150 of the first switch drive unit 171, and the cathode may be connected to the node between the capacitor and the control unit 182. In the bootstrap circuit unit 160 configured as described above, when the power factor improvement switch unit 140 is turned on, such as Figure 11 The P1 path is formed as shown to receive power from the drive power supply 150 and charge the capacitor; and when the power factor improvement switch unit 140 is turned off, the energy charged in the capacitor can be used to drive the control unit 182. A resistor can be used in series with a diode to limit the current flowing when the capacitor is charging.

[0071] In this way, since the bootstrap circuit unit 160 is connected to the drive power supply 150 of the first switch drive unit 171, there are no limitations in its use compared to the case of using a switch drive unit with a lower switch (second lower switch 132).

[0072] Control units 181, 182, and 183 may include isolation functions to isolate signals. Additionally, separate power circuitry may be included to generate power for the switch drive units 171, 172, and 173. For example, the power circuitry may use a linear regulator, an isolated or non-isolated converter, etc.

[0073] like Figure 12 As shown, diode 161 in bootstrap circuit unit 160 can block reverse voltage when the output voltage is applied in the opposite direction. Path P2 is the current path of the bridgeless power factor correction converter, and path P3 is the bootstrap reverse voltage path. Diode 161 in bootstrap circuit unit 160 can be used to block the bootstrap reverse voltage path. For this purpose, it is necessary to use diode 161 with a breakdown voltage higher than the output voltage.

[0074] Figure 13 This is a block diagram of a bridgeless power factor improvement converter according to another embodiment of the present invention; and Figure 14 This is an exemplary circuit diagram of a bridgeless power factor improvement converter according to another embodiment of the present invention. Figure 13 and Figure 14 In the detailed description of a bridgeless power factor improvement converter according to another embodiment of the present invention, the terms corresponding to... Figures 1 to 12 The description of the bridgeless power factor improvement converter partially overlaps with the description of the bridgeless power factor improvement converter.

[0075] A bridgeless power factor correction converter 200 according to another embodiment of the present invention includes: a power input unit 210 for receiving power; a first rectifier unit 220 and a second rectifier unit 230 for rectifying the received power; and a power factor correction switching unit 240 connected to the first rectifier unit 220 and the second rectifier unit 230 for improving the power factor according to an on / off operation. The first rectifier unit 220 includes a first upper switch 221 and a first lower switch 222, and the second rectifier unit 230 includes a second upper switch 231 and a second lower switch 232. The first upper switch 221 and the second upper switch 231 can be driven by a drive power supply 251 connected to a control unit 281 for controlling the drive of the power factor correction switching unit 240. Here, the first lower switch 222 can be driven by a drive power supply 252 connected to the control unit 283, which controls the drive of the second lower switch 232.

[0076] According to another embodiment of the present invention, the first rectifier unit 220 of the bridgeless power factor correction converter 200 may be configured with a switch instead of a diode. That is, the first rectifier unit 220 is configured with a first lower switch 222 and a first upper switch 221 corresponding to the second rectifier unit 230, and the first upper switch 221 can be driven by a drive power supply 251 connected to a first switch drive unit 271 for controlling the drive of the power factor correction switch unit 240. In this way, the drive power supply used to drive the upper switch 221 of the first rectifier unit 220 and the upper switch 231 of the second rectifier unit 230 can be reduced. Furthermore, the first lower switch 222 can be driven by a drive power supply 252 connected to a third switch drive unit 273 for controlling the drive of the second lower switch 232. In this way, the drive power supply used to drive the lower switch (first lower switch 222) of the first rectifier unit 220 can be reduced. In other words, the power factor improvement switching unit 240, the first upper switch 221, the first lower switch 222, the second upper switch 231, and the second lower switch 232 can be driven using only two driving power supplies 251 and 252.

[0077] Specifically, the power factor improvement switching unit 230 can be controlled by a control unit 281, which is driven by a drive power supply 251 included in the first switch driving unit 271. The first upper switch 221 can be controlled by a fourth switch driving unit 274, and the fourth switch driving unit 274 can include: a control unit 284 for controlling the gate voltage of the first upper switch 221; and a bootstrap circuit unit 262 for receiving power from the drive power supply 251 of the first switch driving unit 171 and supplying power to the control unit 284. Similarly, the second upper switch 231 can be controlled by a second switch driving unit 272, and the second switch driving unit 272 can include: a control unit 282 for controlling the gate voltage of the second upper switch 231; and a bootstrap circuit unit 262 for receiving power from the drive power supply 251 of the first switch driving unit 171 and supplying power to the control unit 282.

[0078] Figure 15 This is a block diagram of a bridgeless power factor improvement converter according to another embodiment of the present invention; and Figure 16 This is an exemplary circuit diagram of a bridgeless power factor improvement converter according to another embodiment of the present invention. Figure 15 and Figure 16 In the detailed description of a bridgeless power factor improvement converter according to another embodiment of the present invention, the terms corresponding to... Figures 1 to 14 The description of the bridgeless power factor improvement converter partially overlaps with the description of the bridgeless power factor improvement converter.

[0079] A bridgeless power factor correction converter 300 according to another embodiment of the present invention includes: a power input unit 310 for receiving power; and a power factor correction switching unit 340 connected to a first rectifier unit 320 and a second rectifier unit 330 for rectifying the input power, and improving the power factor according to on / off operations by connecting to the first rectifier unit 320 and the second rectifier unit 330. The first rectifier unit 320 includes a first upper switch 321 and a first lower switch 322, wherein the first upper switch 321 is driven by a drive power supply 350 connected to a first switch drive unit 371, which includes a control unit 381 for controlling the drive of the power factor correction switching unit 340. In the bridgeless power factor correction converter 300 according to another embodiment of the present invention, the first rectifier unit 320 is configured with the first upper switch 321 and the first lower switch 322, and the second rectifier unit 330 may be configured with an upper diode 331 and a lower diode 332. At this time, the first upper switch 321 is driven by the drive power supply 350 of the first switch drive unit 371 connected to the drive unit 340 for controlling the power factor improvement switch unit, thereby potentially reducing the drive power supply used to drive the first upper switch 321.

[0080] Those skilled in the art will understand that this embodiment can be implemented in modified forms without departing from the basic characteristics described above. Therefore, the disclosed methods should be considered illustratively rather than restrictively. The scope of the invention is shown in the claims rather than in the foregoing description, and all differences within the equivalent scope are to be interpreted as included in the invention.

Claims

1. A bridgeless power factor correction converter, comprising: A power input unit configured to receive power; The first rectifier unit and the second rectifier unit are configured to rectify the received power. as well as A power factor improvement switching unit, connected to the first rectifier unit and the second rectifier unit, is configured to improve the power factor based on on / off operations. The second rectifier unit includes a second upper switch and a second lower switch, and The second upper switch is driven by a drive power supply connected to the power factor improvement switch unit.

2. The bridgeless power factor correction converter according to claim 1, comprising: A first switch driving unit is configured to drive the power factor improvement switch unit; A second switch driving unit is configured to drive the second upper switch; as well as A third switch driving unit is configured to drive the second down switch. The second switch driving unit receives power from the driving power supply of the first switch driving unit.

3. The bridgeless power factor correction converter according to claim 2, wherein, The second switch driving unit includes: A control unit configured to control the gate voltage of the second upper switch; and The bootstrap circuit unit is configured to receive power from the drive power supply of the first switch drive unit and supply the power to the control unit.

4. The bridgeless power factor correction converter according to claim 3, wherein, The bootstrap circuit unit includes a capacitor and a diode connected to the drive power supply of the first switch drive unit.

5. The bridgeless power factor correction converter according to claim 4, wherein, One end of the capacitor in the bootstrap circuit unit is connected to the control unit, and the other end is connected to the source of the MOSFET switch, which is the second upper switch. In this configuration, the anode of the diode in the bootstrap circuit unit is connected to the drive power supply of the first switch drive unit, and the cathode is connected to the node between the capacitor and the control unit.

6. The bridgeless power factor correction converter according to claim 1, wherein, The power factor improvement switching unit includes two MOSFET switches, the sources of which are connected to each other.

7. The bridgeless power factor correction converter according to claim 6, wherein, The sources of the two MOSFET switches in the power factor improvement switching unit are connected to the drive power supply of the power factor improvement switching unit.

8. The bridgeless power factor correction converter according to claim 1, wherein, The first rectifier unit includes an upper diode and a lower diode, and One end of the power factor improvement switching unit is connected to the node between the upper diode and the lower diode, and the other end is connected to the node between the second upper switch and the second lower switch.

9. The bridgeless power factor correction converter according to claim 1, wherein, The power input unit receives AC power or DC power.

10. The bridgeless power factor correction converter according to claim 1, wherein, The power input unit includes an inductor.

11. The bridgeless power factor correction converter of claim 1, comprising: Output capacitors connected to the output terminals of the first rectifier unit and the second rectifier unit.

12. A bridgeless power factor correction converter, comprising: A power input unit configured to receive power; The first rectifier unit and the second rectifier unit are configured to rectify the received power. as well as A power factor improvement switching unit, connected to the first rectifier unit and the second rectifier unit, is configured to improve the power factor based on on / off operations. The first rectifier unit includes a first upper switch and a first lower switch. The second rectifier unit includes a second upper switch and a second lower switch, and The first upper switch and the second upper switch are connected to and driven by the power factor improvement switching unit.

13. The bridgeless power factor correction converter according to claim 12, wherein, The first down switch is driven by a drive power supply connected to the second down switch.

14. The bridgeless power factor correction converter of claim 12, comprising: A first switch driving unit is configured to drive the power factor improvement switch unit; A second switch driving unit is configured to drive the second upper switch; as well as A third switch driving unit is configured to drive the second down switch. The second switch driving unit receives power from the driving power supply of the first switch driving unit.

15. The bridgeless power factor correction converter according to claim 14, wherein, The second switch driving unit includes: A control unit configured to control the gate voltage of the second upper switch; and The bootstrap circuit unit is configured to receive power from the drive power supply of the first switch drive unit and supply the power to the control unit.

16. The bridgeless power factor correction converter according to claim 15, wherein, The bootstrap circuit unit includes a capacitor and a diode connected to the drive power supply of the first switch drive unit.

17. The bridgeless power factor correction converter according to claim 16, wherein, One end of the capacitor in the bootstrap circuit unit is connected to the control unit, and the other end is connected to the source of the MOSFET switch, which is the second upper switch. In this configuration, the anode of the diode in the bootstrap circuit unit is connected to the drive power supply of the first switch drive unit, and the cathode is connected to the node between the capacitor and the control unit.

18. The bridgeless power factor correction converter according to claim 12, wherein, The power factor improvement switching unit includes two MOSFET switches, the sources of which are connected to each other.

19. The bridgeless power factor correction converter according to claim 18, wherein, The sources of the two MOSFET switches in the power factor improvement switching unit are connected to the drive power supply of the power factor improvement switching unit.

20. A bridgeless power factor correction converter, comprising: A power input unit configured to receive power; The first rectifier unit and the second rectifier unit are configured to rectify the received power. as well as A power factor improvement switching unit, connected to the first rectifier unit and the second rectifier unit, is configured to improve the power factor based on on / off operations. The first rectifier unit includes a first upper switch and a first lower switch. The first upper switch is connected to and driven by the power factor improvement switch unit's drive power supply.

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