WO2015180107A1

WO2015180107A1 - Dc power source circuit

Info

Publication number: WO2015180107A1
Application number: PCT/CN2014/078829
Authority: WO
Inventors: 王合球
Original assignee: 深圳欧陆通电子有限公司
Priority date: 2014-05-29
Filing date: 2014-05-29
Publication date: 2015-12-03

Abstract

A DC power source circuit, comprising a PFC rectifier module (10), and further comprising a boost module (20) and a resonant converter (30). The input of the boost module is connected to the output of the PFC rectifier module, the output of the boost module is connected to the input of the resonant converter, and the output of the resonant converter is the output of the DC power source circuit.

Description

Title of Invention: A DC Power Supply Circuit

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[1] The present invention relates to the field of power supplies, and more particularly to a DC power supply circuit.

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[2] The DC power supply circuit is generally a two-stage structure. The first stage is a PFC rectifier circuit, which is used to rectify the AC voltage and increase the power factor value to reduce the harmonics to provide DC power to the second stage. The second stage is A DC-DC conversion circuit for converting a voltage to meet an output voltage specification.

[3] In the DC power supply circuit, the output voltage terminal is connected with an electrolytic capacitor for voltage regulation in parallel. If the electrolytic capacitor is used for a long time, the electrolyte may leak, resulting in a large capacitance error of the electrolytic capacitor. Therefore, electrolysis The life of the capacitor determines the service life of the DC power supply, especially for the LED power supply. Therefore, how to avoid the use of electrolytic capacitors is the key to improving the service life of the power supply.

[4] The technical problem to be solved by the present invention is that, in view of the defect that the DC power supply has a low service life due to the use of an electrolytic capacitor in the prior art, a DC power supply circuit is provided, which can improve the life of the DC power supply without using an electrolytic capacitor. .

[5] The technical solution adopted by the present invention to solve the technical problem thereof is: constructing a DC power supply circuit, including

a PFC rectifier module, the DC power supply circuit further includes a boosting module and a resonant converter, and an input end of the boosting module is connected to an output end of the PFC rectifier module, and an output end of the boosting module is connected to the An input end of the resonant converter, an output end of the resonant converter being an output end of the DC power supply circuit.

[6] In the DC power supply circuit of the present invention, the boosting module includes a first inductor, a first switching transistor, a first diode, and a first capacitor, wherein the first end of the first inductor Connecting a positive output end of the PFC rectifier module, a second end of the first inductor is respectively connected to a positive pole of the first diode and a first end of the first switch transistor, the first diode The negative terminal is connected to the first end of the first capacitor, and the second end of the first switch tube and the second end of the first capacitor are respectively connected to the negative output end of the PFC rectifier module. [7] In the DC power supply circuit of the present invention, the resonant converter includes a square wave conversion circuit, a resonance circuit, a rectifier circuit, and a filter circuit that are sequentially connected.

[8] In the DC power supply circuit of the present invention, the square wave conversion circuit is a half bridge inverter circuit or a full bridge inverter circuit.

[9] In the DC power supply circuit of the present invention, the resonant circuit includes a transformer, the rectifying circuit includes a second switching tube and a third switching tube, and the same name and different ends of the primary winding of the transformer The first end and the second output end of the square wave conversion circuit are respectively connected, and the same end of the first secondary winding of the transformer is connected to the first end of the second switching tube, and the first end of the transformer a different end of the second secondary winding is connected to the first end of the third switching tube, and a different end of the first secondary winding of the transformer is connected to a same end of the second secondary winding of the transformer, The second end of the second switch tube and the second end of the third switch tube are grounded.

[10] In the DC power supply circuit of the present invention, the filter circuit includes a second inductor, a second capacitor, and a third capacitor, wherein the first end of the second inductor is connected to the first pair of the transformer a second end of the second inductor is a positive output end of the DC power supply circuit, and a second capacitor is connected between the first end of the second inductor and ground, A third capacitor is coupled between the second end of the second inductor and ground.

[11] In the DC power supply circuit of the present invention, the DC power supply circuit further includes:

[12] It is used to detect the output voltage of the DC power supply circuit, and turn off the overvoltage protection module of the PFC rectifier module when the voltage detection value is greater than the voltage preset value.

[13] In the DC power supply circuit of the present invention, the DC power supply circuit further includes:

[14] It is used to detect the output current of the DC power circuit and turn off the overcurrent protection module of the PFC rectifier module when the current detection value is greater than the current preset value.

[15] In the DC power supply circuit of the present invention, the DC power supply circuit further includes:

[16] It is used to detect the temperature of the DC power supply circuit and turn off the over-temperature protection module of the PFC rectifier module when the temperature detection value is greater than the temperature preset value.

[17] In the DC power supply circuit of the present invention, the DC power supply circuit further includes:

[18] An EMI filter connected to the PFC rectifier circuit and used to suppress electromagnetic interference signals.

[19] Implementing the technical solution of the present invention, the PFC rectifier module rectifies and performs power on the AC input voltage Factor correction, but because the bandwidth of the PFC rectifier module is narrow and the loop response is slow, the DC voltage output by the PFC rectifier module is very unstable. However, since the boost module can boost the DC voltage outputted by the PFC rectifier module, the DC voltage can be quickly adjusted to achieve stability, which can make up for the instability of the output voltage of the PFC rectifier module, and achieve the purpose of replacing the electrolytic capacitor. Finally, the resonant converter converts the DC voltage output from the boost module to meet the output voltage specification. Moreover, the resonant converter can be completely independent of the electrolytic capacitor compared to the prior art DC/DC converter. Therefore, the DC power supply circuit of this embodiment can omit the electrolytic capacitor, thereby increasing the life of the DC power supply.

DRAWINGS

[20] The present invention will be further described below in conjunction with the accompanying drawings and embodiments, in which:

1 is a logic diagram of a first embodiment of a DC power supply circuit of the present invention;

2 is a circuit diagram of a second embodiment of a DC power supply circuit of the present invention.

detailed description

1 is a logic diagram of a first embodiment of a DC power supply circuit of the present invention. The DC power supply circuit includes a PFC rectifier module 10, a boost module 20 and a resonant converter 30, and an input terminal of the boost module 20. Connected to the output of the PFC rectifier module 10, the output of the boost module 20 is coupled to the input of the resonant converter 30, and the output of the resonant converter 30 is the output of the DC power supply circuit. In the DC power supply circuit of the embodiment, the PFC rectifier module 10 rectifies the AC input voltage and performs power factor correction. However, since the bandwidth of the PFC rectifier module 10 is narrow, the loop response is slow. Therefore, the PFC rectifier module 10 The output DC voltage is very unstable. However, since the boosting module 20 can boost the DC voltage outputted by the PFC rectifier module 10, the DC voltage can be quickly adjusted to achieve stability, which can compensate for the instability of the output voltage of the PFC rectifier module 10, and achieve the purpose of replacing the electrolytic capacitor. Finally, the resonant converter 30 converts the DC voltage outputted by the boosting module 20 to meet the output voltage index, and the resonant converter 30 can be completely independent of the electrolysis compared to the prior art DC/DC converter. capacitance. Therefore, the DC power supply circuit of this embodiment can omit the electrolytic capacitor, thereby increasing the life of the DC power source.

2 is a circuit diagram of a second embodiment of a DC power supply circuit according to the present invention. The DC power supply circuit includes a fuse F1, an EMI filter, a PFC rectifier module, a boost module, and a resonant converter, which are sequentially connected, and each part is described below. : [25] The EMI filter includes a common mode inductor L1, a capacitor C1 and a capacitor C2, wherein the first end of the common mode inductor L1 is connected to the first end of the AC input voltage through the fuse F1, and the second end of the common mode inductor L1 is connected. The second end of the common mode inductor L1 is connected to the first input end of the PFC rectifier module, and the fourth end of the common mode inductor L1 is connected to the second input end of the PFC rectifier module. The capacitor C1 is connected between the first end and the second end of the common mode inductor L1, and the capacitor C2 is connected between the third end and the fourth end of the common mode inductor L2.

[26] In the PFC rectifier module, the diodes D1, D2, D3, and D4 form a diode rectifier bridge, and the two input ends of the diode rectifier bridge are respectively connected to the third end and the fourth end of the common mode inductor L1, and the diode rectifier bridge The positive output is connected to the first end of the inductor L4 and the first end of the capacitor C3, the second end of the inductor L4 is connected to the anode of the diode D5 and the drain of the MOS transistor Q1, and the cathode of the diode D5 is connected to the first end of the capacitor C4. The second end of the capacitor C3, the source of the MOS transistor Q1, and the second end of the capacitor C4 are respectively connected to the negative output terminal of the diode rectifier bridge.

[27] In the boost module, the first end of the inductor L3 is connected to the cathode of the diode D5, the second end of the inductor L3 is connected to the anode of the diode D6 and the drain of the MOS transistor Q2, and the cathode of the diode D6 is connected to the capacitor C5 first. The source of the MOS transistor Q2 and the second terminal of the capacitor C5 are respectively connected to the negative output terminal of the diode rectifier bridge.

[28] In the resonant converter, the resonant converter includes a square wave conversion circuit, a resonance circuit, a rectifier circuit, and a filter circuit which are sequentially connected. The square wave conversion circuit selects a half bridge inverter circuit. In the half bridge inverter circuit, the drain of the MOS transistor Q3 and the first end of the capacitor C7 are respectively connected to the cathode of the diode D6, and the source of the MOS transistor Q3 is connected to the MOS. The second end of the capacitor C7 is connected to the first end of the capacitor C8, and the source of the MOS transistor Q4 and the second end of the capacitor C8 are respectively connected to the negative output end of the diode rectifier bridge. In the resonant circuit, the same end of the primary winding of the transformer TX2 is connected to the second end of the capacitor C7, and the different end of the primary winding of the transformer TX2 is connected to the source of the MOS transistor Q3 through the capacitor C6, and the first secondary side of the transformer TX2 The opposite end of the winding is connected to the same end of its second secondary winding. In the rectifier circuit, the same name of the first secondary winding of the transformer TX2 is connected to the drain of the MOS transistor Q5, and the different terminal of the second secondary winding of the transformer TX2 is connected to the drain of the MOS transistor Q6, the source of the MOS transistor Q5. It is grounded together with the source of MOS transistor Q6. In the filter circuit, the first end of the inductor L5 is connected to the different end of the first secondary winding of the transformer TX2, and the capacitor C9 is connected between the first end of the inductor L5 and the ground, and the capacitor C10 is connected. Connected between the second end of the inductor L5 and the ground.

[29] It should be noted that the driving of the gates of the MOS transistors Q1, Q2, Q3, Q4, Q5, Q6 is not shown.

It should be understood that in practical applications, a corresponding driver is required.

[30] The following explains the working principle of the DC power supply circuit: When there is an AC input voltage input, the AC input voltage is suppressed by the fuse Fl and the common mode inductor L1, and then sent to the diode rectifier bridge for rectification. Then, the power factor value is boosted by controlling the on and off of the MOS transistor Q1 to supply a DC voltage to the boost module. Next, in the boosting module, the inductor L3 is charged and discharged by controlling the on and off of the MOS transistor Q2, so that the voltage of the capacitor C5 reaches a stable high DC voltage. In the resonant converter, the DC voltage outputted by the boosting module is converted into a square wave voltage by controlling the on and off of the MOS transistors Q3 and Q4, and is loaded on the primary winding of the transformer TX2, coupled by the transformer TX2, and then passed. The on/off of the MOS transistors Q5 and Q6 is controlled so that the voltage on the capacitor C9 is a DC voltage, and the DC voltage is filtered by the inductor L5 and the capacitor C10 to output a power supply to meet the power supply requirement of the load.

[31] Finally, it should be noted that the square wave conversion circuit in this embodiment may also be a full bridge inverter circuit.

[32] In addition, preferably, the DC power supply circuit of the present invention may further include at least one of an overvoltage protection module, an overcurrent protection module, and an overtemperature protection module. The overvoltage protection module is configured to detect an output voltage of the DC power supply circuit, and turn off the PFC rectifier module when the voltage detection value is greater than a voltage preset value. The overcurrent protection module is configured to detect an output current of the DC power supply circuit, and turn off the PFC rectifier module when the current detection value is greater than a current preset value. The over temperature protection module is configured to detect the temperature of the DC power supply circuit, and turn off the PFC rectifier module when the temperature detection value is greater than the temperature preset value.

The above description is only the preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications, combinations and changes may be made to the present invention. Any modifications, equivalent substitutions, improvements, etc. within the spirit and scope of the invention are intended to be included within the scope of the appended claims.

Claims

Claim

A DC power supply circuit, comprising a PFC rectifier module, wherein the DC power supply circuit further includes a boosting module and a resonant converter, and an input end of the boosting module is connected to an output end of the PFC rectifier module, An output end of the boosting module is connected to an input end of the resonant converter, and an output end of the resonant converter is an output end of the DC power supply circuit.

The DC power supply circuit according to claim 1, wherein the boosting module comprises a first inductor, a first switching transistor, a first diode, and a first capacitor, wherein the first inductor is first The first end of the first inductor is connected to the positive end of the first diode and the first end of the first switch tube, the first diode A cathode of the first capacitor is connected to a first end of the first capacitor, and a second end of the first capacitor is connected to a negative terminal of the PFC rectifier module.

A DC power supply circuit according to claim 2, wherein said resonant converter comprises a square wave converting circuit, a resonant circuit, a rectifying circuit and a filtering circuit which are sequentially connected.

The DC power supply circuit according to claim 3, wherein the square wave conversion circuit is a half bridge inverter circuit or a full bridge inverter circuit.

The DC power supply circuit according to claim 3, wherein the resonant circuit comprises a transformer, the rectifying circuit comprises a second switching tube and a third switching tube, and the same-name end of the primary winding of the transformer The different ends are respectively connected to the first output end and the second output end of the square wave conversion circuit, and the same end of the first secondary winding of the transformer is connected to the first end of the second switch tube, the transformer a different end of the second secondary winding is connected to the first end of the third switching tube, and the different end of the first secondary winding of the transformer is connected to the same end of the second secondary winding of the transformer. The second end of the second switch tube and the second end of the third switch tube are grounded. The DC power supply circuit according to claim 5, wherein the filter circuit comprises a second inductor, a second capacitor, and a third capacitor, wherein the second inductor The first end is connected to the different end of the first secondary winding of the transformer, the second end of the second inductor is a positive output end of the DC power circuit, and the second capacitor is connected to the second inductor Between the first end and the ground, the third capacitor is coupled between the second end of the second inductor and ground.

The DC power supply circuit according to claim 1, wherein the DC power supply circuit further comprises:

It is used for detecting the output voltage of the DC power supply circuit, and turning off the overvoltage protection module of the PFC rectifier module when the voltage detection value is greater than the voltage preset value.

It is used for detecting the output current of the DC power supply circuit, and turning off the overcurrent protection module of the PFC rectifier module when the current detection value is greater than the current preset value.

It is used to detect the temperature of the DC power supply circuit, and turn off the over temperature protection module of the PFC rectifier module when the temperature detection value is greater than the temperature preset value.

An EMI filter connected to the PFC rectifier circuit and used to suppress electromagnetic interference signals.