TWI697181B - Dc-to-dc converter with a power factor correction function - Google Patents

Abstract

A DC-to-DC converter with a power factor correction function is provided for providing uninterruptible power supply to a load. The DC-to-DC converter with the power factor correction function includes a first circuit coupled to a live end of an AC power source, a second circuit coupled to the live end of the AC power source and a neutral end of the AC power source, and a third circuit coupled to the first circuit, the second circuit, and the neutral line end. The first circuit includes a first power switch circuit and a backup battery coupled in series to the first power switch. The first power switch circuit is coupled to the live end. The second circuit includes an energy storage unit and a second power switching circuit coupled in series to the energy storage unit. The energy storage unit is coupled to the live end and the first power switch circuit, and the second power switch circuit is coupled to the neutral end and the backup battery.

Description

DC-DC converter with power factor correction function

The invention relates to a DC-to-DC converter, in particular to a DC-to-DC converter with power factor correction function applied in an uninterruptible power system.

Generally speaking, when the converter with Power Factor Correction (PFC) function is applied to the battery mode of the current uninterruptible power system (UPS) under the 3kVA architecture, in the case of abnormal power grid or power outage Uninterrupted power supply for electrical appliances and other load equipment to provide backup AC power to maintain the normal operation of electrical equipment. Normally, the uninterruptible power supply system is used to maintain uninterrupted power supply for critical commercial equipment or precision instruments such as computers and servers to prevent data loss, communication interruption, or device control.

However, the current uninterruptible power supply system (UPS), when operating in the battery mode of the 3kVA architecture, is most commonly used with lead-acid batteries, which are large in size, short in life, and time-consuming and costly to maintain. And the traditional DC-to-DC converter is a push-pull (Push-Pull) architecture, which is different from the Boost boost circuit at one end of the AC power grid. In this way, it will occupy too much wiring area on the circuit board, increase the circuit board base material and process time, and due to the volume of the lead-acid battery and increase the Push-Pull circuit structure, the volume and cost of the uninterruptible power system will therefore increase .

To this end, how to design an improved DC-DC converter, especially in the simplification of the line architecture, to solve the aforementioned technical problems of increasing the volume and cost of the uninterruptible power system is the important research of the inventor of the present case Subject.

The purpose of the present invention is to provide a DC-to-DC converter with power factor correction function, which can solve the technical problems of increasing the volume and cost of the uninterruptible power system by simplifying the improvement of the line structure, thereby reducing the production cost and improving Production efficiency and the purpose of being portable.

In order to achieve the foregoing objective, the DC-DC converter with power factor correction function proposed by the present invention is applied to provide continuous power supply to the load in the commercial mode or battery mode. The DC-DC converter with power factor correction function includes : First circuit, coupled to the live terminal of the AC power supply; the first circuit includes a first power switch circuit and a backup battery coupled in series; wherein, the first power switch circuit is coupled to the live terminal; the second circuit, coupled to the AC The live terminal and the neutral terminal of the power supply, and the second circuit is coupled to the first circuit; the second circuit includes an energy storage unit and a second power switch circuit coupled in series; wherein the energy storage unit is coupled to the live terminal and the first power A switch circuit, the second power switch circuit is coupled to the neutral terminal and the backup battery; and a third circuit is coupled to the first circuit, the second circuit, and the neutral terminal; wherein, the third circuit is coupled to the The backup battery, the energy storage unit of the second circuit, and the second power switch circuit; wherein, when the AC power supply is normal, the AC power supply provides the mains mode power supply to the load through the second circuit and the third circuit; when the AC power supply is abnormal, The backup battery provides battery mode power supply to the load through the first power switch circuit, the second circuit, and the third circuit.

Further, in the DC-DC converter with power factor correction function, the first power switch circuit includes a first diode and a first transistor switch coupled in series; wherein, the first diode is coupled The energy storage unit connected to the live end and the second circuit, the first transistor switch is coupled to the backup battery.

Further, in the DC-DC converter with power factor correction function, the second power switch circuit includes a fourth transistor switch and a second transistor switch and a third transistor switch coupled in series; wherein, One end of the fourth transistor switch is coupled to the second transistor switch and the third transistor switch, and the other end of the fourth transistor switch is coupled to the backup battery and the third circuit; wherein, the second transistor switch is coupled to the energy storage The unit and the third circuit, the third transistor switch is coupled to the neutral terminal.

Further, in the DC-DC converter with power factor correction function, the third circuit includes a second diode, a third diode, a first capacitor, and a second capacitor coupled in series; wherein, The second diode is coupled to the fourth transistor of the second circuit and the backup battery of the first circuit, the third diode is coupled to the energy storage unit of the second circuit and the second transistor, the first capacitor and the second The capacitor is coupled to the neutral terminal and the third transistor switch of the second circuit.

Further, in the DC-DC converter with power factor correction function, when operating in the mains mode, and when the DC-DC converter is operating in the positive half cycle: the first transistor switch is turned off, the second The transistor switch is turned on, the third transistor switch is turned on, and the fourth transistor switch is turned off, and the energy storage unit is an energy storage operation; and the first transistor switch is turned off, the second transistor switch is turned off, and the third transistor switch It is turned off and the fourth transistor switch is turned off, and the energy storage unit is operated for energy release.

Further, in the DC-DC converter with power factor correction function, when operating in the mains mode, and when the DC-DC converter is operating in a negative half cycle: the first transistor switch is turned off, the second The transistor switch is turned on, the third transistor switch is turned on, and the fourth transistor switch is turned off, and the energy storage unit is an energy storage operation; and the first transistor switch is turned off, the second transistor switch is turned off, and the third transistor switch It is turned off and the fourth transistor switch is turned off, and the energy storage unit is operated for energy release.

Further, in the DC-DC converter with power factor correction function, when operating in battery mode, and when the DC-DC converter is operating in the positive half cycle: the first transistor switch is turned on, the second power The crystal switch is turned on, the third transistor switch is turned on, and the fourth transistor switch is turned on, and the energy storage unit is an energy storage operation; and the first transistor switch is turned on, the second transistor switch is turned off, the third transistor switch is turned on, and the first The four transistor switch is turned on, and the energy storage unit is operated for energy release.

Further, in the DC-DC converter with power factor correction function, when operating in battery mode, and when the DC-DC converter is operating in a negative half cycle: the first transistor switch is turned on, the second power The crystal switch is turned on, the third transistor switch is turned on, and the fourth transistor switch is turned on, and the energy storage unit is an energy storage operation; and the first transistor switch is turned on, the second transistor switch is turned on, the third transistor switch is turned on, and the fourth The transistor switch is turned off, and the energy storage unit operates for energy release.

Further, in the DC-DC converter with power factor correction function, the energy storage unit is an inductor, and the backup battery is a lithium battery.

When using the DC-DC converter with power factor correction function according to the present invention, if the AC power is normal, the AC power is provided to the load through the second circuit and the third circuit Power supply in mains mode, where the second circuit and the third circuit can perform voltage conversion processing (for example: Boost) on the AC power supply and provide it to the load; if the AC power supply is abnormal (for example: surge, undervoltage or power failure), The first power switch circuit of the first circuit and the second power switch circuit of the second circuit can be controlled by the on and off of the circuit, so that the power output by the backup battery can enter the second circuit and the second circuit through the first power switch circuit The three circuits perform voltage conversion processing, so that the backup battery provides battery mode power supply to the load through the first power switch circuit, the second circuit, and the third circuit.

For this reason, when the AC power supply is abnormal, only the first power switch circuit can make the backup battery perform voltage conversion processing through the second circuit and the third circuit, and does not need to be independent of the AC power supply flow path. For other voltage conversion circuits (such as Push-Pull converters), the present invention simplifies the improvement of the circuit architecture, does not need to occupy additional circuit board volume and wiring area, can reduce the circuit board substrate and process time, and thus solve the uninterrupted power supply The technical problem of increasing the volume and cost of the system has achieved the goals of reducing production costs, improving production efficiency and being portable for use.

In order to further understand the technology, means and effects of the present invention to achieve the intended purpose, please refer to the following detailed description and drawings of the present invention. I believe that the features and characteristics of the present invention can be gained an in-depth and specific understanding However, the accompanying drawings are provided for reference and explanation only, and are not intended to limit the present invention.

10: First circuit

11: The first power switch circuit

12: Backup battery

20: Second circuit

21: Energy storage unit

22: Second power switch circuit

30: Third circuit

D1: the first diode

D2: Second diode

D3: third diode

D4: Fourth diode

L1: Energy storage unit

200: load

300: input filter circuit

400: inverter

500: output filter circuit

Q1: The first transistor switch

Q2: Second transistor switch

Q3: third transistor switch

Q4: Fourth transistor switch

C1: the first capacitor

C2: second capacitor

L: FireWire

N: Neutral terminal

Lns1: the first energy storage path

Lns2: second energy storage path

Lns3: third energy storage path

Lns4: fourth energy storage path

Lnr1: the first energy release path

Lnr2: the second energy release path

Lnr3: The third energy release path

Lnr4: the fourth energy release path

B1: Backup battery

FIG. 1 is a schematic structural diagram of an embodiment of a DC-DC converter with power factor correction function configured in an uninterruptible power system according to the present invention; FIG. 2 is a circuit schematic diagram of the embodiment of the DC-DC converter with power factor correction function of the present invention; FIG. 3 is an embodiment of the DC-DC converter with power factor correction function of the present invention operating in The schematic diagram of the first energy storage path in the mains mode and the positive half cycle operation; FIG. 4 is the first embodiment of the DC-DC converter with power factor correction function according to the present invention operating in the mains mode and the positive half cycle operation. A schematic diagram of an energy release path; FIG. 5 is a schematic diagram of a second energy storage path when the embodiment of the DC-DC converter with power factor correction function according to the present invention operates in a commercial power mode and operates in a negative half cycle; FIG. 6 is a diagram The second energy-releasing path diagram of the embodiment of the DC-DC converter with power factor correction function in the invention operating in the mains mode and negative half-cycle operation; FIG. 7 is the DC with power factor correction function of the invention The schematic diagram of the third energy storage path when the embodiment of the DC converter operates in the battery mode and the positive half cycle operation; FIG. 8 is the embodiment of the DC-DC converter with power factor correction function according to the present invention. FIG. 9 is a schematic diagram of a third energy release path during battery mode and positive half cycle operation; FIG. 9 is the first embodiment of the DC-to-DC converter with power factor correction function of the present invention operating in battery mode and negative half cycle operation. Four energy storage path diagrams; FIG. 10 is a schematic diagram of a fourth energy release path when the embodiment of the DC-DC converter with power factor correction function of the present invention operates in battery mode and negative half cycle operation; and FIG. 11 is Another embodiment of the DC-to-DC converter with power factor correction function according to the present invention is a schematic diagram of a fifth energy release path when operating in a commercial power mode and operating in a negative half cycle.

The following is a description of the embodiments of the present invention by specific specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied by other different specific examples. Various details in the description of the present invention can also be modified and changed based on different viewpoints and applications without departing from the spirit of the present invention.

It should be noted that the structure, proportion, size, number of elements, etc. shown in the drawings in this specification are only used to match the contents disclosed in the specification for those familiar with this technology to understand and read, not to limit the invention. The implementation of the limited conditions, so it does not have the technical significance, any structural modification, proportional relationship change or size adjustment, without affecting the effectiveness of the present invention can be achieved and the purpose can be achieved, should fall within this The technical content disclosed by the invention can be covered.

The technical content and detailed description of the present invention are explained below in conjunction with the drawings.

Please refer to FIG. 1 and FIG. 2, wherein FIG. 1 is a schematic structural view of an embodiment of a DC-DC converter with power factor correction function configured in a continuous power system according to the present invention; FIG. 2 is a schematic view of the present invention The circuit schematic diagram of the embodiment of the DC-DC converter with power factor correction function. One embodiment of the DC-DC converter with power factor correction function of the present invention is applied to provide continuous power supply to the load 200 in the commercial mode or the battery mode. The DC-DC converter with power factor correction function includes: A circuit 10, a second circuit 20, and a third circuit 30.

Among them, the first circuit 10 is coupled to the live terminal L of the AC power supply; the first circuit 10 includes a first power switch circuit 11 and a backup battery 12 coupled in series B1, which is a lithium battery in this embodiment); wherein, the first power switch circuit 11 is coupled to the live terminal. In detail, the first power switch circuit 11 includes a first diode D1 and a first transistor switch Q1 coupled in series; wherein, the first diode D1 is coupled to the live terminal L and the energy storage of the second circuit 20 In the unit 21 (element labeled L1 in the figure, which is an inductor in this embodiment), the first transistor switch Q1 is coupled to the backup battery B1.

The second circuit 20 is coupled to the live terminal L and the neutral terminal N of the AC power source, and the second circuit 20 is coupled to the first circuit 10; the second circuit 20 includes an energy storage unit 21 and a second power switch circuit coupled in series 22; wherein, the energy storage unit L1 is coupled to the live terminal L and the first power switch circuit 11, the second power switch circuit 22 is coupled to the neutral terminal N and the backup battery B1. In detail, the second power switch circuit 22 includes a fourth transistor switch Q4 and a second transistor switch Q2 and a third transistor switch Q3 coupled in series; one end of the fourth transistor switch Q4 is coupled to the second Transistor switch Q2 and third transistor switch Q3, and the other ends of fourth transistor switch Q4 are coupled to backup battery B1 and third circuit 30; wherein second transistor switch Q2 is coupled to energy storage unit L1 and third In circuit 30, the third transistor switch Q3 is coupled to the neutral terminal N.

The third circuit 30 is coupled to the first circuit 10, the second circuit 20, and the neutral terminal N; wherein, the third circuit 30 is coupled to the backup battery B1 of the first circuit 10, the energy storage unit L1 of the second circuit 20, and Second power switch circuit 22. In detail, the third circuit 30 includes a second diode D2, a third diode D3, a first capacitor C1, and a second capacitor C2 coupled in series; wherein, the second diode D2 is coupled to the second circuit The fourth transistor switch Q4 of 20 and the backup battery B1 of the first circuit 10, the third diode D3 is coupled to the energy storage unit L1 of the second circuit 20 and the second transistor switch Q2, the first capacitor C1 and the first The two capacitors C2 are coupled to the neutral terminal N and the third transistor switch Q3 of the second circuit 20.

Incidentally, the aforementioned respective transistor switches may be, for example but not limited to, metal oxide semiconductor field effect transistors (MOSFET), double carrier junction transistors (BJT) or insulated gate bipolar transistors (IGBT) .

In the embodiment of the present invention, the DC-to-DC converter with power factor correction function is coupled to the input filter circuit 300, which may be an EMI filter circuit for filtering electromagnetic interference of the input AC power supply (Electromagnetic Interference, EMI) and other noises (as shown in Figure 1), and the DC-DC converter with power factor correction function is coupled to the DC-DC converter with power factor correction function by coupling the inverter 400 The DC power output from the converter is converted to AC power, and the output filter circuit 500 is coupled to the EMI filter circuit to filter out noise such as electromagnetic interference output to the load 200. When the AC power supply is normal, the AC power supply provides power to the load 200 through the second circuit 20 and the third circuit 30 in the mains mode; when the AC power supply is abnormal, the backup battery B1 passes through the first power switch circuit 11 and the second circuit 20 and the third circuit 30 provide battery mode power supply to the load 200.

Please refer to FIG. 3 and FIG. 4. FIG. 3 is a schematic diagram of a first energy storage path when the embodiment of the DC-DC converter with power factor correction function according to the present invention operates in a commercial mode and is operating in a positive half cycle; FIG. 4 is a schematic diagram of a first energy release path when the embodiment of the DC-DC converter with power factor correction function according to the present invention operates in the commercial mode and operates in the positive half cycle. The DC-to-DC converter with power factor correction function described above operates in the mains mode (when the AC power supply is normal), and when the DC-to-DC converter is operating in the positive half cycle: as shown in FIG. 3, by controlling the first The transistor switch Q1 is turned off, the second transistor switch Q2 is turned on, the third transistor switch Q3 is turned on, and the fourth transistor switch Q4 is turned off. At this time, the energy storage unit L1 is an energy-storing operation; When the energy storage unit L1 is During the energy storage operation, the live terminal L, the energy storage unit L1, the second transistor switch Q2, the third transistor switch Q3, and the neutral terminal N form a first energy storage path Lns1 for storing energy in the energy storage unit L1; and As shown in FIG. 4, by controlling the first transistor switch Q1 to turn off, the second transistor switch Q2 to turn off, the third transistor switch Q3 to turn off, and the fourth transistor switch Q4 to turn off, at this time, the energy storage unit L1 is an energy-releasing operation; when the energy storage unit L1 is an energy-releasing operation, the live terminal L, the energy storage unit L1, the third diode D3, the first capacitor C1 and the neutral terminal N are formed The first energy release path Lnr1 of the energy storage unit L1 releases energy.

Please refer to FIG. 5 and FIG. 6. FIG. 5 is a schematic diagram of a second energy storage path when the embodiment of the DC-DC converter with power factor correction function according to the present invention operates in a commercial mode and operates in a negative half cycle; FIG. 6 is a schematic diagram of a second energy release path when the embodiment of the DC-DC converter with power factor correction function according to the present invention operates in a commercial power mode and operates in a negative half cycle. The DC-to-DC converter with power factor correction function described above operates in the mains mode (when the AC power supply is normal), and when the DC-to-DC converter is operating in a negative half cycle: as shown in FIG. 5, by controlling the first Transistor switch Q1 is off, second transistor switch Q2 is on, third transistor switch Q3 is on and fourth transistor switch Q4 is off. At this time, the energy storage unit L1 is an energy storage operation; when the energy storage unit L1 is During the energy storage operation, the neutral terminal N, the third transistor switch Q3, the second transistor switch Q2, the energy storage unit L1, and the live terminal L form a second energy storage path Lns2 that stores energy to the energy storage unit L1.

As shown in FIG. 6, by controlling the first transistor switch Q1 to turn off, the second transistor switch Q2 to turn off, the third transistor switch Q3 to turn off, and the fourth transistor switch Q4 to turn off, at this time, the energy storage unit L1 is the energy release operation; when the energy storage unit L1 is the energy release operation, the neutral terminal N, The second capacitor C2, the second diode D2, the fourth transistor switch Q4, the second transistor switch Q2, the energy storage unit L1, and the live terminal L form a second energy release path Lnr2 for energy release of the energy storage unit L1. Incidentally, for the energy releasing operation of the energy storage unit L1, since the second transistor switch Q2 and the fourth transistor switch Q4 are in an off state, the second energy releasing path Lnr2 of the energy storing unit L1 to release energy This is achieved through the freewheeling path provided by the reverse (parasitic) diode of the second transistor switch Q2 and the reverse (parasitic) diode of the fourth transistor switch Q4.

Please refer to FIG. 7 and FIG. 8. FIG. 7 is a schematic diagram of a third energy storage path when the embodiment of the DC-DC converter with power factor correction function of the present invention operates in a battery mode and is operating in a positive half cycle; FIG. 8 is a schematic diagram of a third energy release path when the embodiment of the DC-DC converter with power factor correction function of the present invention operates in a battery mode and operates in a positive half cycle. The DC-to-DC converter with power factor correction function described above operates in battery mode (when the AC power supply is abnormal), and when the DC-to-DC converter is operating in the positive half cycle: as shown in FIG. 7, by controlling the first The transistor switch Q1 is turned on, the second transistor switch Q2 is turned on, the third transistor switch Q3 is turned on, and the fourth transistor switch Q4 is turned on. At this time, the energy storage unit L1 is an energy storage operation; when the energy storage unit L1 is an energy storage During operation, the positive electrode of the backup battery B1, the first transistor switch Q1, the first diode D1, the energy storage unit L1, the second transistor switch Q2, the fourth transistor switch Q4, and the negative electrode of the backup battery B1 are formed The third energy storage path Lns3 storing energy for the energy storage unit L1.

As shown in FIG. 8, by controlling the first transistor switch Q1 to turn on, the second transistor switch Q2 to turn off, the third transistor switch Q3 to turn on, and the fourth transistor switch Q4 to turn on, at this time, the energy storage unit L1 is released Can operate; when the energy storage unit L1 is the energy release operation, the anode of the backup battery B1, the first transistor switch Q1, the first diode D1, the energy storage unit L1, the third diode D3, the first capacitor C1, the third transistor switch Q3, the fourth transistor switch Q4, and the negative electrode of the backup battery B1 form a third energy release path Lnr3 for releasing energy of the energy storage unit L1.

Please refer to FIG. 9 and FIG. 10. FIG. 9 is a schematic diagram of a fourth energy storage path when the embodiment of the DC-DC converter with power factor correction function of the present invention operates in a battery mode and operates in a negative half cycle; FIG. 10 is a schematic diagram of a fourth energy release path when the embodiment of the DC-DC converter with power factor correction function of the present invention operates in a battery mode and operates in a negative half cycle. The DC-to-DC converter with power factor correction function described above operates in battery mode (when the AC power supply is abnormal), and when the DC-to-DC converter is operating in a negative half cycle: as shown in FIG. 9, by controlling the first The transistor switch Q1 is turned on, the second transistor switch Q2 is turned on, the third transistor switch Q3 is turned on, and the fourth transistor switch Q4 is turned on. At this time, the energy storage unit L1 is an energy storage operation; when the energy storage unit L1 is an energy storage During operation, the positive electrode of the backup battery B1, the first transistor switch Q1, the first diode D1, the energy storage unit L1, the second transistor switch Q2, the fourth transistor switch Q4, and the negative electrode of the backup battery B1 are formed The fourth energy storage path Lns4 storing energy for the energy storage unit L1.

As shown in FIG. 10, by controlling the first transistor switch Q1 to turn on, the second transistor switch Q2 to turn on, the third transistor switch Q3 to turn on, and the fourth transistor switch Q4 to turn off, at this time, the energy storage unit L1 is released Can operate; when the energy storage unit L1 is the energy release operation, the anode of the backup battery B1, the first transistor switch Q1, the first diode D1, the energy storage unit L1, the second transistor switch Q2, the third transistor The switch Q3, the second capacitor C2, the second diode D2, and the negative electrode of the backup battery B1 form a fourth energy release path Lnr4 for releasing energy of the energy storage unit L1.

Please refer to FIG. 11, which is a fifth energy-releasing circuit of another embodiment of the DC-DC converter with power factor correction function according to the present invention when it is operated in the mains mode and operates in the negative half cycle Path schematic. It is roughly the same as the embodiment shown in FIG. 6 when it is operating in the commercial power mode and is operating in the negative half cycle, but this embodiment is newer than the previous embodiment by adding a fourth diode D4, which is coupled at one end The energy storage unit L1, the second transistor switch Q2, and the third diode D3 are connected. The other end of the fourth diode D4 is coupled to the second diode D2 and the second capacitor C2.

As shown in FIG. 11, by controlling the first transistor switch Q1 to turn off, the second transistor switch Q2 to turn off, the third transistor switch Q3 to turn off, and the fourth transistor switch Q4 to turn off, at this time, the energy storage unit L1 is the energy release operation; when the energy storage unit L1 is the energy release operation, the neutral terminal N, the second capacitor C2, the fourth diode D4, the energy storage unit L1 and the live terminal L form the energy storage unit L1 energy release The fifth energy release path Lnr5. Compared to the second energy release path Lnr2 shown in FIG. 6, the fifth energy release path Lnr5 shown in FIG. 11 avoids passing through the fourth transistor switch Q4 and the second transistor switch Q2 in the path, which can effectively reduce the power The conduction loss and switching loss of the crystal switch, the additional power consumption and the delay of the reaction time caused by the parasitic resistance and parasitic capacitance of the device can further improve the conversion efficiency, circuit response and reduce the operating cost.

As mentioned above, when the DC-DC converter with power factor correction function according to the present invention is used, if the AC power supply is normal, the AC power supply provides the mains mode power supply to the load 200 through the second circuit 20 and the third circuit 30 , Where the second circuit 20 and the third circuit 30 can perform voltage conversion processing (for example: Boost) on the AC power supply to the load; if the AC power supply is abnormal (for example: surge, undervoltage or power failure), the first The first power switch circuit 11 of the circuit 10 and the second power switch circuit 22 of the second circuit 20 can be controlled by the on and off of the circuit, so that the power output by the backup battery B1 can enter the first power switch circuit 11 The second circuit 20 and the third circuit 30 perform voltage conversion processing to make the backup battery B1 The first power switch circuit 11, the second circuit 20, and the third circuit 30 provide battery mode power supply to the load.

For this reason, when the AC power is abnormal, only the first power switch circuit 11 can make the backup battery B1 perform the voltage conversion process through the second circuit 20 and the third circuit 30, without the need to independently flow through the AC power supply. For other voltage conversion circuits (such as Push-Pull converters) outside the path, the present invention improves through simplified circuit architecture, does not need to occupy additional circuit board volume and wiring area, and can reduce circuit board substrate and process time, and Solve the technical problems of increasing the volume and cost of the uninterruptible power system, and achieve the goals of reducing production costs, improving production efficiency, and being portable for use.

In addition, the backup battery B1 of the present invention is not a traditional lead-acid battery, but a lithium battery. The conventional known lead-acid batteries have the disadvantages of large volume, heavy weight, and short service life. For this reason, the DC-DC converter with power factor correction function described in the present invention has other advantages such as small size, light weight, better service life and reliability.

The above is only the detailed description and drawings of the preferred embodiments of the present invention, but the features of the present invention are not limited to this, and are not intended to limit the present invention. All the scope of the present invention should be applied for the following patent scope Subject to the spirit of the patent application scope of the present invention and the embodiments of similar changes, should be included in the scope of the present invention, any person familiar with the art in the field of the present invention, can easily think of changes or Modifications can be covered in the patent scope of the following case.

10: First circuit

11: The first power switch circuit

12: Backup battery

20: Second circuit

21: Energy storage unit

22: Second power switch circuit

30: Third circuit

200: load

300: input filter circuit

400: inverter

500: output filter circuit

Claims (13)

A DC-DC converter with power factor correction function is applied to provide continuous power supply of a mains mode or a battery mode to a load. The DC-DC converter with power factor correction function includes: a first circuit , Coupled to a live terminal of an AC power source; the first circuit includes a first power switch circuit and a backup battery coupled in series; wherein, the first power switch circuit is coupled to the live terminal, the first power The switch circuit includes a first diode and a first transistor switch coupled in series; a second circuit is coupled to the live terminal and a neutral terminal of the AC power supply, and the second circuit is coupled to the The first circuit; the second circuit includes an energy storage unit and a second power switch circuit coupled in series; wherein, the energy storage unit is coupled to the live terminal and the first power switch circuit, the second power switch circuit Coupled to the neutral terminal and the backup battery, the first diode is coupled to the live terminal and the energy storage unit of the second circuit, the first transistor switch is coupled to the backup battery; and a A third circuit, coupled to the backup battery of the first circuit, the energy storage unit of the second circuit, the second power switch circuit and the neutral terminal; wherein, when the AC power supply is normal, the AC The power supply provides the mains mode power supply to the load through the second circuit and the third circuit; when the AC power supply is abnormal, the backup battery passes through the first power switch circuit, the second circuit, and the third circuit pair The load provides the battery mode power supply; wherein, the second power switch circuit includes a fourth transistor switch and a second transistor switch and a third transistor switch coupled in series, the fourth transistor switch One end coupled The second transistor switch and the third transistor switch, the other end of the fourth transistor switch is coupled to the backup battery and the third circuit, the second transistor switch is coupled to the energy storage unit and the first Three circuits, the third transistor switch is coupled to the neutral terminal. The DC-to-DC converter with power factor correction function as described in item 1 of the patent scope, wherein the third circuit includes a second diode, a third diode, and a first coupled in series A capacitor and a second capacitor; wherein, the second diode is coupled to the fourth transistor of the second circuit and the backup battery of the first circuit, and the third diode is coupled to the second circuit The energy storage unit and the second transistor, the first capacitor and the second capacitor are coupled to the neutral terminal and the third transistor switch of the second circuit. The DC-to-DC converter with power factor correction function as described in item 2 of the patent application scope, wherein when operating in the mains mode and when the DC-to-DC converter is operating for a positive half cycle: the first The transistor switch is turned off, the second transistor switch is turned on, the third transistor switch is turned on, and the fourth transistor switch is turned off, the energy storage unit is an energy storage operation; and the first transistor switch is turned off, The second transistor switch is turned off, the third transistor switch is turned off and the fourth transistor switch is turned off, and the energy storage unit is operated for energy release. The DC-to-DC converter with power factor correction function as described in item 3 of the patent application scope, wherein, when the energy storage unit is in an energy storage operation, the live end, the energy storage unit, and the second transistor switch , The third transistor switch and the neutral terminal form a first energy storage path; and when the energy storage unit is in energy release operation, the live end, the energy storage unit, the third diode, the The first capacitor and the neutral terminal form a first energy release path. The DC-to-DC converter with power factor correction function as described in item 2 of the patent application scope, wherein when operating in the mains mode and when the DC-to-DC converter is operating in a negative half cycle: the first The transistor switch is turned off, the second transistor switch is turned on, the third transistor switch is turned on, and the fourth transistor switch is turned off, the energy storage unit is an energy storage operation; and the first transistor switch is turned off, The second transistor switch is turned off, the third transistor switch is turned off and the fourth transistor switch is turned off, and the energy storage unit is operated for energy release. The DC-to-DC converter with power factor correction function as described in item 5 of the patent application scope, wherein, when the energy storage unit is an energy storage operation, the neutral terminal, the third transistor switch, the first The two transistor switches, the energy storage unit and the live terminal form a second energy storage path; and when the energy storage unit is in energy release operation, the neutral terminal, the second capacitor and the second diode , The fourth transistor switch, the second transistor switch, the energy storage unit and the live end form a second energy release path. The DC-to-DC converter with power factor correction function as described in item 2 of the patent application scope, wherein when operating in the battery mode and when the DC-to-DC converter is operating in a positive half cycle: the first The transistor switch is turned on, the second transistor switch is turned on, the third transistor switch is turned on, and the fourth transistor switch is turned on, the energy storage unit is for energy storage operation; and the first transistor switch is turned on, the second When the transistor switch is turned off, the third transistor switch is turned on, and the fourth transistor switch is turned on, the energy storage unit operates for energy release. The DC-DC converter with power factor correction function as described in item 7 of the patent application scope, wherein, when the energy storage unit is in energy storage operation, a positive electrode of the backup battery, the first transistor switch, The first diode, the energy storage unit, the second transistor switch, the fourth transistor switch, and a negative electrode of the backup battery form a third energy storage path; and when the energy storage unit is an energy release During operation, the anode of the backup battery, the first transistor switch, the first diode, the energy storage unit, the third diode, the first capacitor, the third transistor switch, the The fourth transistor switch and the negative electrode of the backup battery form a third energy release path. The DC-to-DC converter with power factor correction function as described in item 2 of the patent application scope, wherein when operating in the battery mode and when the DC-to-DC converter is operated for a negative half cycle: the first The transistor switch is turned on, the second transistor switch is turned on, the third transistor switch is turned on, and the fourth transistor switch is turned on, the energy storage unit is for energy storage operation; and the first transistor switch is turned on, the second When the transistor switch is turned on, the third transistor switch is turned on, and the fourth transistor switch is turned off, the energy storage unit is operated for energy release. The DC-DC converter with power factor correction function as described in item 9 of the patent application scope, wherein, when the energy storage unit is in energy storage operation, a positive electrode of the backup battery, the first transistor switch, The first diode, the energy storage unit, the second transistor switch, the fourth transistor switch, and a negative electrode of the backup battery form a fourth energy storage path; and When the energy storage unit is in energy release operation, the positive electrode, the first transistor switch, the first diode, the energy storage unit, the second transistor switch, and the third transistor of the backup battery The switch, the second capacitor, the second diode, and the negative electrode of the backup battery form a fourth energy release path. The DC-DC converter with power factor correction function as described in item 2 of the patent scope, wherein the third circuit further includes a fourth diode; wherein, one end of the fourth diode is coupled to the The energy storage unit, the second transistor switch and the third diode, the other end of the fourth diode is coupled to the second diode and the second capacitor. The DC-to-DC converter with power factor correction function as described in item 11 of the patent application scope, wherein when operating in the mains mode and when the DC-to-DC converter is operated for a negative half cycle: the first The transistor switch is turned off, the second transistor switch is turned on, the third transistor switch is turned on and the fourth transistor switch is turned off, the energy storage unit is an energy storage operation; and the first transistor switch is turned off, The second transistor switch is turned off, the third transistor switch is turned off and the fourth transistor switch is turned off, and the energy storage unit is operated for energy release. The DC-to-DC converter with power factor correction function as described in item 12 of the patent application scope, wherein, when the energy storage unit is in an energy storage operation, the neutral terminal, the third transistor switch, the first Two transistor switches, the energy storage unit and the live terminal form a second energy storage path; and when the energy storage unit is in energy release operation, the neutral terminal, the second capacitor and the fourth diode , The energy storage unit and the live end form a fifth energy release path.

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