Staggered power supply conversion system adapting to wide input voltage

文档序号：1864358 发布日期：2021-11-19 浏览：14次中文

阅读说明：本技术 适应宽输入电压的交错型电源转换系统 (Staggered power supply conversion system adapting to wide input voltage ) 是由周波吴建军周斌朗代志康海东于 2021-08-25 设计创作，主要内容包括：本发明提供的一种适应宽输入电压的交错型电源转换系统,包括交流输入单元、第一分压器件、第二分压器件、启动电路、变压器T1、变压器T2、采样及隔离控制模块Ⅰ、采样及隔离控制模块Ⅱ、输出整流滤波模块Ⅰ、输出整流滤波模块Ⅱ、输出保护模块、交错控制模块以及输出反馈单元；通过上述结构,能够适应不同等级交流电压输入并将交流电转换为直流电并提供给直流负载,在使用过程中无需改变抽头,简化使用方式,而且其能够具有可扩展的输出功率,具有更强的实用性,而且启动可靠,输出电压稳定,能够有效确保整个系统的供电稳定性。(The invention provides an alternating power supply conversion system adaptive to wide input voltage, which comprises an alternating current input unit, a first voltage division device, a second voltage division device, a starting circuit, a transformer T1, a transformer T2, a sampling and isolating control module I, a sampling and isolating control module II, an output rectifying and filtering module I, an output rectifying and filtering module II, an output protection module, an alternating control module and an output feedback unit, wherein the alternating current input unit is connected with the first voltage division device; through above-mentioned structure, can adapt to different grades alternating voltage input and convert the alternating current into the direct current and provide direct current load, need not to change in the use and take a percentage, simplify the using-way, it can have extensible output moreover, has stronger practicality, starts reliably moreover, and output voltage is stable, can effectively ensure entire system's power supply stability.)

1. An alternating power conversion system adapted to a wide input voltage, comprising: the device comprises an alternating current input unit, a first voltage division device, a second voltage division device, a starting circuit, a transformer T1, a transformer T2, a sampling and isolation control module I, a sampling and isolation control module II, an output rectifying and filtering module I, an output rectifying and filtering module II, an output protection module, an interleaving control module and an output feedback unit;

the alternating current input unit is used for converting alternating current into direct current and outputting the direct current, one end of the first voltage divider is connected to the output end of the alternating current input unit, and the first voltage divider is grounded through the second voltage divider;

one end of a primary winding of a transformer T1 is connected to a common connection point between a first voltage divider and an output end of an alternating current input unit, the other end of the primary winding of a transformer T1 is connected to a control end of a sample and isolation control module I, one end of a feedback winding of a transformer T1 is connected to a detection input end of the sample and isolation control module I, the other end of the feedback winding of the transformer T1 is grounded, one end of a secondary winding of a transformer T1 is connected to an input end of an output rectifying and filtering module I, the other end of the secondary winding of the transformer T1 is grounded, an output end of the output rectifying and filtering module I is connected with an input end of an output protection module, and an output end of the output protection module supplies power to a direct current load;

one end of a primary winding of the transformer T2 is connected to a common connection point of the first voltage divider and the second voltage divider, the other end of the primary winding of the transformer T1 is connected to a control end of the sample and isolation control module II, one end of a feedback winding of the transformer T2 is connected to a detection input end of the sample and isolation control module II, the other end of the feedback winding of the transformer T1 is grounded, one end of a secondary winding of the transformer T2 is connected to an input end of the output rectification filter module II, the other end of the secondary winding of the transformer T2 is grounded, and an output end of the output rectification filter module II is connected with an input end of the output protection module;

2. The interleaved power conversion system according to claim 1, wherein: the first voltage division device and the second voltage division device are both capacitance voltage division devices, and the capacitance values of the two capacitance voltage division devices are equal.

3. The interleaved power converter circuit as claimed in claim 1, wherein: the starting circuit comprises an input circuit and a delay switch control circuit;

the input circuit is used for carrying out voltage stabilization treatment on the direct current output by the alternating current input module and outputting the direct current;

and the input end of the delay switch control circuit is connected to the output end of the input circuit and is used for receiving the direct current output by the input circuit, delaying and conducting the direct current and outputting the direct current to the staggered control circuit.

4. The interleaved power conversion system of claim 3 further comprising: the input circuit comprises a resistor R1, a resistor R2, an NMOS tube Q1, a diode D1, a resistor R3, a triode Q2 and a voltage regulator tube ZD 1;

the positive electrode of the diode D1 is used as the input end of the transmission circuit, the negative electrode of the diode D1 is connected to the drain electrode of the NMOS tube Q1 through a resistor R2, the negative electrode of the diode D1 is connected to the grid electrode of the NMOS tube Q1 through a resistor R1, the grid electrode of the NMOS tube Q1 is connected with the negative electrode of the voltage regulator tube ZD1, the positive electrode of the voltage regulator tube ZD1 is grounded, and the source electrode of the NMOS tube Q1 is connected to one end of the resistor R3;

the base electrode of the triode Q2 is connected with the source electrode of the NMOS tube Q1, the collector electrode of the triode Q2 is connected with the grid electrode of the NMOS tube Q1, the emitter electrode of the triode Q2 is connected with the other end of the resistor R3, and the common connection point between the resistor R3 and the emitter electrode of the triode Q1 serves as the output end of the input circuit.

5. The interleaved power conversion system of claim 3 further comprising: the delay control circuit comprises a resistor R5, a resistor R6, a capacitor C4, a capacitor C3, a control chip U1, a resistor R9, a capacitor C5, a resistor R6, a resistor R8, a resistor R7, a PMOS tube Q3, a diode D3, a triode Q4, a diode D4, a capacitor C6, a resistor R10, a resistor R11, a voltage regulator tube ZD2 and a diode D2;

the control chip U1 is a PPS3701 chip;

one end of the capacitor C3 is connected with one end of the resistor R5, the other end of the capacitor C3 is grounded, the other end of the resistor R5 is grounded through a resistor R4, a common connection point between the resistor R5 and the capacitor C3 is connected to the output end of the input circuit, and a common connection point between the resistor R4 and the resistor R5 is connected to a pin 3 and a pin 4 of the control chip U1; the common connection point between the resistor R4 and the resistor R5 is grounded through a capacitor C4;

one end of the resistor R9 is connected to the output end of the input circuit, the other end of the resistor R9 is grounded through a capacitor C5, a common connection point between the resistor R9 and the capacitor C5 is connected to a pin 5 of the control chip U1, a pin 2 of the control chip U1 is grounded, and a pin 6 of the control chip U1 is connected to the cathodes of the diode D3 and the diode D2;

one end of the resistor R6 is connected to the source electrode of the PMOS tube Q3, the other end of the resistor R6 is connected to the anode of the diode D3 through the resistor R8, the common connection point between the resistor R6 and the resistor R8 is connected to the grid electrode of the PMOS tube Q3, the source electrode of the PMOS tube Q3 is connected to the output end of the input circuit, and the drain electrode of the PMOS tube Q3 is connected to the 4 pins of the control chip U1 through the resistor R7;

the triode Q4 is a P-type triode, an emitter of the triode Q4 is connected to the output end of the input circuit, a collector of the triode Q4 is connected with the anode of the diode D4, the cathode of the diode D4 is grounded through a capacitor C6, a common connection point between the capacitor C6 and the diode D4 serves as the output end of the time delay switch circuit, the emitter of the triode Q4 is connected to the base of the triode Q4 through a resistor R10, the base of the triode Q4 is connected to the cathode of a voltage regulator tube ZD2 through the resistor R11, and the anode of the voltage regulator tube ZD2 is connected with the anode of the diode D2.

6. The interleaved power conversion system according to claim 1, wherein: the output protection module comprises a current detection circuit, an output switch control circuit, a voltage detection circuit and a power supply circuit;

the power supply input end of the current detection circuit is used as the input end of the output protection module and is connected with the output ends of the output rectification filter module I and the output rectification filter module II, and the power supply output end of the current detection circuit is connected with the power supply input end of the output switch control circuit and is used for detecting the output current of the direct-current power supply and outputting a current detection signal to the output switch control circuit;

the voltage detection circuit is used for detecting the voltages output by the output rectifying and filtering module I and the output rectifying and filtering module II and outputting a voltage detection signal to the output switch control circuit;

the current detection input end of the output switch control circuit is connected with the output end of the current detection circuit, the voltage detection input end of the output switch control circuit is connected with the output end of the voltage detection circuit, and the output switch control circuit is used for receiving the voltage detection signal and the current detection signal and turning off a power supply loop of the direct current load when overvoltage or overcurrent occurs;

7. The interleaved power conversion system of claim 6 further comprising: the current detection circuit comprises a resistor R12, a resistor R13, a resistor R14, a resistor R15, a resistor R16, a resistor R18, a capacitor C9, a capacitor C13 and a control chip U2;

the resistor R12 is a current detection resistor, one end of the resistor R12 is used as the input end of the current detection circuit and is connected to the output end of the output rectifying and filtering module I, and the other end of the resistor R12 is used as the power supply output end of the current detection circuit;

the control chip U2 is an LT6108 chip, 8 pins of the control chip U2 are connected to a common connection point between a resistor R12 and an output end of a direct-current power supply through a resistor R13, 7 pins of the control chip U2 are connected to a common connection point between a resistor R12 and an output end of the direct-current power supply, one end of a resistor R14 is connected to a common connection point between a resistor R12 and an output end of an output rectification filter module I, the other end of the resistor R14 is grounded through a resistor R15, a common connection point between a resistor R14 and a resistor R15 is connected to a 2 pin of the control chip U2, a pin 1 of the control chip U2 is connected to a resistor R12 serving as one end of an output end of a current detection circuit, a pin 6 of the control chip U2 is grounded after being connected in series through a resistor R9 and a resistor R18, a common connection point between a resistor R16 and a resistor R18 is connected to a pin 5 of the control chip U2, a pin 5 of the control chip U2 is grounded through a capacitor C13, the pin 4 of the control chip U2 is grounded, and the pin 3 of the control chip U2 serves as a detection output end of the current detection circuit.

8. The interleaved power conversion system of claim 6 further comprising: the output switch control circuit comprises a PMOS (P-channel metal oxide semiconductor) tube Q5, a triode Q6, a triode Q7, a triode Q8, a resistor R17, a resistor R19, a resistor R20, a resistor R21, a resistor R22, a resistor R23, a resistor R32, a capacitor C10, a capacitor C11, a diode D5, a diode D6, a diode D8, a diode D9 and a control chip U3;

the control chip U3 is a PPS3701 chip;

the source of the PMOS transistor Q5 is used as the power input end of the output switch control circuit, the drain of the PMOS transistor Q1 is used as the power output end of the output switch control circuit, the source of the PMOS transistor Q1 is connected with the negative electrode of the voltage regulator ZD3, the positive electrode of the voltage regulator ZD3 is connected with the gate of the PMOS transistor Q5, the source of the PMOS transistor Q5 is connected with the gate of the PMOS transistor Q5 through a resistor R20, the source of the PMOS transistor Q5 is connected with one end of a capacitor C10, the other end of the capacitor C10 is connected with the gate of the PMOS transistor Q5 through a resistor R21, the source of the PMOS transistor Q5 is connected with the gate of the PMOS transistor Q11 through a capacitor C11, the gate of the PMOS transistor Q11 is connected with the positive electrode of a diode D11 through a resistor R11, the negative electrode of the diode D11 is connected with the collector of the triode Q11, the emitter of the triode Q11 is connected with the 6 pin of the control chip U11, the base of the triode Q11 is connected with the negative electrode of the diode D11, and the positive electrode of the power output end of the diode Q11;

the triode Q6 is a P-type triode, the emitter of the triode Q6 is connected to the source of a PMOS tube Q5, the collector of the triode Q6 is connected to the gate of a PMOS tube Q5, the emitter of the triode Q6 is connected to the base of the triode Q6 through a resistor R17, the base of the triode Q6 is connected to the anode of a diode D5, the cathode of the diode D5 is connected to the collector of the triode Q8 through a resistor R19, the emitter of the triode Q8 is connected to the 1 pin of a control chip U3, the base of the triode Q8 is connected to the cathode of a diode D8 through a resistor R32, the anode of the diode D8 is connected to the output end of the power supply circuit, the collector of the triode Q8 is also connected to the cathode of a diode D10, and the anode of the diode D10 is connected to the first output end of the voltage detection circuit;

9. The interleaved power conversion system of claim 6 further comprising: the voltage detection circuit comprises a resistor R29, a resistor R28, a resistor R27, a resistor R26, a diode D11, a capacitor C16 and a capacitor C17;

one end of a resistor R29 is connected to the output end of the output rectifying and filtering module I, the other end of the resistor R29 is connected to one end of a resistor R27 through a resistor R28, the other end of the resistor R27 is grounded, the common connection point of the resistor R29 and the resistor R28 is grounded through a capacitor C17, the common connection point of the resistor R29 and the resistor R28 is connected with the cathode of a diode D11, the anode of the diode D11 is connected to the common connection point between the resistor R28 and the resistor R27, the common connection point between the resistor R28 and the resistor R27 is grounded through a capacitor C16, the common connection point between the resistor 28 and the resistor R27 is connected with one end of a resistor R26, the other end of a resistor R26 serves as the detection output end of the voltage detection circuit, and the common connection point of the resistor R29 and the resistor R28 serves as the first output end of the voltage detection circuit.

10. The interleaved power conversion system of claim 6 further comprising: the power supply circuit comprises a capacitor C14, a triode Q9, a resistor R30, a resistor R31, a voltage regulator tube ZD4 and a capacitor C15;

the collector of the triode Q9 is used as the input end of the power circuit, the emitter of the triode Q9 is grounded after being connected in series with the capacitor C15 through the resistor R31, the common connection point between the capacitor C15 and the resistor R31 is used as the output end of the power circuit, the collector of the triode Q9 is grounded through the capacitor C14, the collector of the triode Q9 is connected to the base of the triode Q9 through the resistor R30, the base of the triode Q9 is connected with the negative electrode of the voltage regulator tube ZD4, and the positive electrode of the voltage regulator tube ZD4 is grounded.

Technical Field

The present invention relates to power supply systems, and particularly to an interleaved power supply conversion system adapted to wide input voltage.

Background

In mine power supply of coal mines, AC127V, AC380V, AC660V and AC1140V are generally provided with alternating current voltage specifications, in mine equipment, some direct current equipment needs to be powered by direct current, and in the prior art, AC-DC conversion equipment is generally adopted to convert alternating current into direct current and supply the direct current equipment with the direct current equipment, but the prior conversion system has the following defects: the voltage range of input alternating current of the existing alternating current-direct current conversion equipment is generally 85V-265V, alternating current is converted into about 200V by adopting a power frequency transformer, alternating current-direct current conversion is carried out through an AC-DC converter, and in order to adapt to wide-range voltage input, a mode of multiple groups of input taps is generally adopted: the AC127V group of taps, the AC380V group of taps, the AC660V group of taps, and the AC1140V group of taps, different input voltages need to change the connection mode of the taps, so that the use is very inconvenient, and safety risks exist, for example, the AC-DC conversion device is burnt and even more serious safety accidents are caused if the tap is forgotten to change and high voltage is connected; although the ACDC converter with a low-power ultra-wide input voltage in the prior art (applied to an intelligent electric meter, and also partially applied to the underground coal mine) basically adopts a stacked flyback power supply mode in principle. The power supply adopting the mode has the defects that the output power cannot be expanded, the power is not large, and the requirement of the actual working condition cannot be met.

Moreover, the conventional AC-DC conversion circuit has the problems of unreliable start-up and low safety of output direct current.

Therefore, in order to solve the above technical problems, it is necessary to provide a new technical means.

Disclosure of Invention

In view of the above, an object of the present invention is to provide an interleaved power conversion system suitable for wide input voltage, which can be adapted to ac voltage inputs of different levels, convert ac power into dc power and provide the dc power to a dc load, and does not need to change a tap during use, thereby simplifying a use method, and which has scalable output power, higher practicability, reliable start-up, stable output voltage, and can effectively ensure power supply stability of the entire system.

The invention provides an alternating power supply conversion system adaptive to wide input voltage, which comprises an alternating current input unit, a first voltage division device, a second voltage division device, a starting circuit, a transformer T1, a transformer T2, a sampling and isolating control module I, a sampling and isolating control module II, an output rectifying and filtering module I, an output rectifying and filtering module II, an output protection module, an alternating control module and an output feedback unit, wherein the alternating current input unit is connected with the first voltage division device;

Further, the first voltage divider and the second voltage divider are both capacitance voltage dividers, and the capacitance values of the two capacitance voltage dividers are equal.

Further, the starting circuit comprises an input circuit and a delay switch control circuit;

the input circuit is used for carrying out voltage stabilization treatment on the direct current output by the alternating current input module and outputting the direct current;

Further, the input circuit comprises a resistor R1, a resistor R2, an NMOS tube Q1, a diode D1, a resistor R3, a triode Q2 and a voltage regulator ZD 1;

Further, the delay control circuit comprises a resistor R5, a resistor R6, a capacitor C4, a capacitor C3, a control chip U1, a resistor R9, a capacitor C5, a resistor R6, a resistor R8, a resistor R7, a PMOS tube Q3, a diode D3, a triode Q4, a diode D4, a capacitor C6, a resistor R10, a resistor R11, a voltage regulator tube ZD2 and a diode D2;

the control chip U1 is a PPS3701 chip;

Further, the output protection module comprises a current detection circuit, an output switch control circuit, a voltage detection circuit and a power supply circuit;

Further, the current detection circuit comprises a resistor R12, a resistor R13, a resistor R14, a resistor R15, a resistor R16, a resistor R18, a capacitor C9, a capacitor C13 and a control chip U2;

Further, the output switch control circuit comprises a PMOS tube Q5, a triode Q6, a triode Q7, a triode Q8, a resistor R17, a resistor R19, a resistor R20, a resistor R21, a resistor R22, a resistor R23, a resistor R32, a capacitor C10, a capacitor C11, a diode D5, a diode D6, a diode D8, a diode D9 and a control chip U3;

the control chip U3 is a PPS3701 chip;

Further, the voltage detection circuit comprises a resistor R29, a resistor R28, a resistor R27, a resistor R26, a diode D11, a capacitor C16 and a capacitor C17;

Further, the power supply circuit comprises a capacitor C14, a triode Q9, a resistor R30, a resistor R31, a voltage regulator tube ZD4 and a capacitor C15;

The invention has the beneficial effects that: the invention can adapt to the input of alternating voltage with different grades, convert alternating current into direct current and provide the direct current for a direct current load, does not need to change a tap in the using process, simplifies the using mode, has extensible output power, stronger practicability, reliable starting and stable output voltage, and can effectively ensure the power supply stability of the whole system.

Drawings

The invention is further described below with reference to the following figures and examples:

FIG. 1 is a schematic structural diagram of the present invention.

Fig. 2 is a schematic diagram of the start-up circuit of the present invention.

Fig. 3 is a schematic circuit diagram of an output protection module according to the present invention.

Detailed Description

The invention is described in further detail below with reference to the drawings of the specification:

the invention provides an alternating power supply conversion system adaptive to wide input voltage, which comprises an alternating current input unit, a first voltage division device, a second voltage division device, a starting circuit, a transformer T1, a transformer T2, a sampling and isolating control module I, a sampling and isolating control module II, an output rectifying and filtering module I, an output rectifying and filtering module II, an output protection module, an alternating control module and an output feedback unit, wherein the alternating current input unit is connected with the first voltage division device;

the input end of the starting circuit is connected to a common connection point of the first voltage dividing device and the second voltage dividing device, the output end of the starting circuit is connected with a power supply end of the staggered control module, a control end of the staggered control module is connected with control input ends of the sampling and isolating control module I and the sampling and isolating control module II, a feedback input end of the staggered control module is connected with an output end of an output feedback unit, an input end of the output feedback unit is connected to an input end of the output protection module, and the staggered control module controls the transformer T1 and the transformer T2 to work alternately. The alternating current input unit comprises an EMC filtering and surge suppressing module and a rectifying module, wherein the EMC filtering and surge suppressing module is used for filtering and surge suppressing protection of alternating current, and then the alternating current is rectified by the rectifying module; the output feedback unit comprises an output sampling module and an isolation feedback control module, wherein the output sampling module is used for collecting voltage signals output by an isolation control module I and a sampling and isolation control module II and outputting the voltage signals to the isolation feedback control module, the isolation feedback control module is used for isolating and feeding back feedback voltage signals to the interleaving control module for protecting the interleaving control module, the sampling and isolation control module I, the sampling and isolation control module II, the output rectifying and filtering module I, the output rectifying and filtering module II, the EMC filtering and surge suppression module, the rectifying module output sampling module and the isolation feedback control module in the prior art can be adopted, the details are not repeated, and the interleaving control module is used for respectively outputting PWM control signals to the sampling and isolation control module I and the sampling and isolation control module II, two way PWM control signal's phase place is opposite, thereby make sampling and isolation control module I, sampling and isolation control module II work in turn, and the duty ratio through controlling PWM control signal controls entire system's output, thereby make entire system have the power output scope of broad, stronger adaptability has, through the structure, can adapt to different grades alternating voltage input and change alternating current into direct current and provide direct current load, need not to change in the use and take a percentage, simplify the user mode, and it can have extensible output, stronger practicality has, and the start is reliable, output voltage is stable, can effectively ensure entire system's power supply stability.

In this embodiment, the first voltage divider and the second voltage divider are both capacitance voltage dividers, and the capacitance values of the two capacitance voltage dividers are equal, in fig. 1 and 2, C1 represents the first capacitance voltage divider, and C2 represents the second capacitance voltage divider; through the structure, a good voltage division effect can be achieved, a peak clipping effect can be achieved, and each voltage division device can be formed by connecting one capacitor or more than two capacitors in series.

In the prior art, the stable starting of the interleaving control module is also a technical problem, so in this embodiment, the starting circuit includes an input circuit and a delay switch control circuit;

the input circuit is used for carrying out voltage stabilization treatment on the direct current output by the alternating current input module and outputting the direct current;

Specifically, the method comprises the following steps: the input circuit comprises a resistor R1, a resistor R2, an NMOS tube Q1, a diode D1, a resistor R3, a triode Q2 and a voltage regulator tube ZD 1;

The delay control circuit comprises a resistor R5, a resistor R6, a capacitor C4, a capacitor C3, a control chip U1, a resistor R9, a capacitor C5, a resistor R6, a resistor R8, a resistor R7, a PMOS tube Q3, a diode D3, a triode Q4, a diode D4, a capacitor C6, a resistor R10, a resistor R11, a voltage regulator tube ZD2 and a diode D2;

the control chip U1 is a PPS3701 chip;

After direct current is input, the grid voltage of the NMOS tube Q1 is gradually increased, when the grid voltage is increased to a set value, the NMOS tube is conducted, so that direct current is output, when the current is overlarge, the voltage of the upper end (the end connected with the source electrode of the NMOS tube) of the resistor R3 is increased, so that the triode Q2 is conducted, the grid voltage of the NMOS tube Q1 is reduced, the NMOS tube is in a state of tending to cut off (not completely cut off), the current is reduced, and a good current-limiting protection effect is formed.

The capacitor C3 is used for energy storage buffering, namely, the triode Q4 is switched on when the voltage of the capacitor C3 reaches a set value, so that the voltage requirement of the interleaved control circuit at the starting moment is met, the resistor R5 and the resistor R4 detect the terminal voltage of the capacitor C3, when the terminal voltage is input to a pin 3 and a pin 4 of the control chip U1, the control chip U1 judges whether the voltage of the capacitor C3 is larger than the set voltage value or not, if not, a high-level signal is output by the pin 6, and the triode Q4 does not act and is in a cut-off state; if so, a low level signal is output through pin 6, so as to pull down the base voltage of the transistor Q4, so that the transistor Q4 is turned on, thereby supplying power to the subsequent interleaving control module.

As described above, when the capacitor C3 is in the charging energy storage state, the pin 6 of the control chip U1 is set to a high level, the PMOS transistor Q3 is turned off, and after the pin 6 of the control chip U1 outputs a low-level control signal, the transistor Q4 is turned on, and at this time, the voltage of the capacitor C3 is also reduced along with the turn-on of the Q4, so that the voltages input to the pin 4 and the pin 3 of the control chip U1 are reduced, and even the input voltages at the pin 4 and the pin 3 are lower than a set value, so that the transistor Q4 is turned off again, and the subsequent control chip of the AC-DC power supply cannot be reliably started and stably operated; therefore, when the 6 pin of the control chip U1 outputs a low level, the gate voltage of the PMOS transistor Q3 is pulled low, the PMOS transistor Q3 is turned on, at this time, the resistor R7 and the capacitor R5 form a parallel structure, and the resistance value at this time is smaller than that of the original R5, so that the input voltages of the 4 pin and the 3 pin are maintained in a state larger than a set voltage value, thereby ensuring that the triode Q4 is continuously turned on, and ensuring the power supply stability of the interleaving control circuit.

In this embodiment, the output protection module includes a current detection circuit, an output switch control circuit, a voltage detection circuit, and a power circuit;

and the input end of the power supply circuit is connected with the output ends of the output rectifying and filtering module I and the output rectifying and filtering module II, and the output end of the power supply circuit provides working electricity for the output switch control circuit. Based on above-mentioned structure, can accurately detect output voltage and the electric current of output rectifier and filter module I and output rectifier and filter module II to in time carry out power-off protection when excessive pressure or overcurrent, and have less shutoff spark at the outage in-process, thereby ensure the power consumption safety.

In this embodiment, the current detection circuit includes a resistor R12, a resistor R13, a resistor R14, a resistor R15, a resistor R16, a resistor R18, a capacitor C9, a capacitor C13, and a control chip U2;

In this embodiment, the output switch control circuit includes a PMOS transistor Q5, a transistor Q6, a transistor Q7, a transistor Q8, a resistor R17, a resistor R19, a resistor R20, a resistor R21, a resistor R22, a resistor R23, a resistor R32, a capacitor C10, a capacitor C11, a diode D5, a diode D6, a diode D8, a diode D9, and a control chip U3;

the control chip U3 is a PPS3701 chip;

3 of the control chip U3 is used as a current detection input end of the output switch control circuit, 4 pins of the control chip U3 are used as a voltage detection input end of the output switch control circuit, and 5 pins of the control chip U3 are connected with an output end of the power supply circuit. Through the structure, when the control chip U3 judges that overvoltage or overcurrent exists currently, power-off protection can be executed in time, and the response speed is high.

In this embodiment, the voltage detection circuit includes a resistor R29, a resistor R28, a resistor R27, a resistor R26, a diode D11, a capacitor C16, and a capacitor C17;

In this embodiment, the power circuit includes a capacitor C14, a transistor Q9, a resistor R30, a resistor R31, a voltage regulator ZD4, and a capacitor C15;

the collector of the triode Q9 is used as the input end of the power circuit, the emitter of the triode Q9 is grounded after being connected in series with the capacitor C15 through the resistor R31, the common connection point between the capacitor C15 and the resistor R31 is used as the output end of the power circuit, the collector of the triode Q9 is grounded through the capacitor C14, the collector of the triode Q9 is connected to the base of the triode Q9 through the resistor R30, the base of the triode Q9 is connected with the negative pole of the voltage regulator tube ZD4, and the positive pole of the voltage regulator tube ZD4 is grounded, so that stable working electricity can be provided for the output switch control circuit, wherein the input end of the voltage detection circuit is further provided with a diode D7, as shown in FIG. 3, so as to ensure the stability of the circuit.

The protection execution principle of the output protection module is as follows:

when the output rectifying and filtering module I or the output rectifying and filtering module II outputs direct current which flows through R12, the direct current enters an output switch control circuit and enters a power supply circuit through a diode D7, and the power supply circuit provides direct current for the base electrodes of a triode Q7 and a triode Q8 after voltage stabilization;

because of the existence of the switch circuit capacitor C10 and the capacitor C11, the capacitors C4 and C5 are charged at this time, the PMOS tube Q5 is not conducted, meanwhile, the current detection circuit samples a current signal and inputs the current signal into the control chip U3, the 3 pin of the control chip U3 receives the current detection signal, the control chip U3 receives the voltage detection signal and judges whether the current and the current voltage are larger than the set value, if so, the 6 pin of the control chip U3 outputs a high level, the 1 pin outputs a low level, at this time, the triode Q7 is cut off, the triode Q8 is conducted, the triode Q6 is conducted, so that the PMOS tube Q5 is in a cut-off state, if the voltage and the voltage are normal, at this time, namely, there is no overcurrent or overvoltage state, the 6 pin of the control chip U3 outputs a low level, the 1 pin outputs a high level, the triode Q7 is conducted, the triode Q8 is conducted, because there is no bias voltage between the base and the emitter, then the transistor Q8 is turned off, the transistor Q6 is turned off, and when the voltages of the capacitor C10 and the capacitor C11 reach the reverse bias voltage of the PMOS transistor Q5, the PMOS transistor Q5 is turned on, so that the output switch control circuit supplies power to the subsequent load.

In the working process, if the control chip U3 monitors that there is an overcurrent or an overvoltage, the control circuit outputs a low level from pin 1 first to turn on the transistor Q8, so that the transistor Q6 is turned on to turn off the PMOS transistor Q5, and the pin 6 of the control chip U3 outputs a high level to turn off the transistor Q7, so that the PMOS transistor Q5 is in a stable off state.

In the voltage detection circuit, the common connection point of the resistor R29 and the resistor R28 also provides a voltage signal to the collector of the transistor Q8, and the voltage signal is used for keeping the transistor Q6 turned off when the input voltage and current of the output protection module are normal, so that the Q6 is prevented from misoperation, and the stability of the whole system is ensured.

Finally, the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting, although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all of them should be covered in the claims of the present invention.

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