阅读说明：本技术 一种综合电源 (Integrated power supply ) 是由 吕佳栗 于 2019-09-03 设计创作，主要内容包括：本发明提供了一种综合电源,属于一种电源供电设备,该综合电源包括多个相互隔离、独立工作的线性稳压电源和开关电源,每路电源均具有过压、过流、短路等保护,本发明能够为设备提供工作源、测试标准源、数字模拟电源、继电器工作电源盒散热风扇电源等,该综合电源的输入为220V/50Hz市电,综合电源的输出为4～33V、+5V、+12V、±15V、-100V等多路直流电压电源,具有安全、可靠的工作特点。(The invention provides a comprehensive power supply, which belongs to power supply equipment, and comprises a plurality of linear stabilized voltage power supplies and a switching power supply which are isolated from each other and work independently, wherein each power supply has protection of overvoltage, overcurrent, short circuit and the like.)

1. An integrated power supply, comprising a plurality of mutually isolated switching power supplies and linear power supplies, by which 220V/50Hz mains power can be converted into 4-33V, +5V, +12V, + 15V or-100V DC voltage supplies, wherein:

the switch power supply comprises an input EMC suppression circuit, a rectification filter circuit, an input anti-impact circuit, a high-frequency inverter circuit, a high-frequency transformer, an output rectification filter circuit, a current and voltage sampling circuit and a drive and control protection circuit, wherein an input port of the input EMC suppression circuit is connected with 220V/50Hz commercial power, an output port of the input EMC suppression circuit is connected with an input port of the rectification filter circuit, the input anti-impact circuit is arranged in the rectification filter circuit and used for reducing the instant current during starting, an output port of the rectification filter circuit is connected with an input port of the high-frequency inverter circuit, the high-frequency transformer is arranged in the high-frequency inverter circuit as an executive device of the high-frequency inverter, an output port of the high-frequency inverter circuit is connected with an input port of the output rectification filter circuit, an output port of the output rectification, the output port of the current and voltage sampling circuit is connected with the input port of the driving and control protection circuit, and the output port of the driving and control protection circuit is connected with the control end of the high-frequency inverter circuit;

the linear power supply comprises an input EMC suppression circuit, an isolation transformer, a rectification filter circuit, a linear voltage stabilizing circuit, an output filter circuit and a current and voltage sampling feedback circuit, wherein an input port of the input EMC suppression circuit is connected with 220V/50Hz mains supply, an output port of the input EMC suppression circuit is connected with a primary winding of the isolation transformer, a secondary winding of the isolation transformer is connected with an input end of the rectification filter circuit, an output end of the rectification filter circuit is connected with an input end of the linear voltage stabilizing circuit, an output end of the linear voltage stabilizing circuit is connected with an input end of the output filter circuit, an output end of the output filter circuit is connected with a direct current output port, an input port of the current and voltage sampling feedback circuit is connected with a.

2. The integrated power supply of claim 1, wherein the input EMC suppression circuit comprises a voltage dependent resistor (RV 1), a common mode inductor, an X capacitor, and a Y capacitor, wherein:

the common mode inductor is divided into a first inductor (L1) and a second inductor (L2), and the first inductor (L1) and the second inductor (L2) are sequentially connected to a zero line and a live line in an alternating current circuit; the X capacitor and the Y capacitor are divided into a second capacitor (C2), a third capacitor (C3), a fourth capacitor (C4), a fifth capacitor (C5), a sixth capacitor (C6) and a seventh capacitor (C7); the second capacitor (C2), the piezoresistor (RV 1) and the third capacitor (C3) are arranged at the front end of the first inductor (L1), and the second capacitor (C2), the piezoresistor (RV 1) and the third capacitor (C3) are sequentially arranged between the zero line and the live line; the fourth capacitor (C4) is arranged between the first inductor (L1) and the second inductor (L2), and the second inductor (L2) is arranged between the zero line and the live line; the fifth capacitor (C5), the sixth capacitor (C6) and the seventh capacitor (C7) are arranged at the rear end of the second inductor (L2), the fifth capacitor (C5) is connected between the zero line and the live line in parallel, the sixth capacitor (C6) and the seventh capacitor (C7) are connected in series and then connected with the fifth capacitor (C5) in parallel, and the common point of the sixth capacitor (C6) and the seventh capacitor (C7) is grounded.

3. The integrated power supply of claim 1, wherein the rectifying and smoothing circuit in the switching power supply comprises a rectifying bridge and a PFC circuit, the input anti-surge circuit is disposed between the rectifying bridge and the PFC circuit, and the PFC circuit comprises an eighth capacitor (C8) and a ninth capacitor (C9) for filtering, wherein: the input anti-shock circuit comprises a first resistor (R1), a second resistor (R2) and a first relay (K1), wherein the first resistor (R1) and the second resistor (R2) are connected in series and then connected into the circuit, the first relay (K1) is connected across the first resistor (R1) and the second resistor (R2) in a bridging mode, when the control circuit drives the first relay (K1) to be disconnected, alternating current is rectified by a rectifier bridge and then limited to flow to an eighth capacitor (C8) and a ninth capacitor (C9) in the PFC circuit through the first resistor (R1) and the second resistor (R2) to be charged, and when voltages of the eighth capacitor (C8) and the ninth capacitor (C9) reach a threshold value, the control circuit closes the first relay (K1).

4. The integrated power supply of claim 1, wherein the high frequency inverter circuit employs LLC resonant soft switching technology.

5. The integrated power supply of claim 1, wherein the gate of the control MOS transistor in the output rectifying and filtering circuit is driven by a charge pump.

6. The integrated power supply of claim 1, wherein the linear voltage regulator circuit comprises a regulating tube, a reference voltage source, a sampling circuit and an error amplifying circuit, wherein a sampling resistor in the sampling circuit outputs a sampling voltage by sampling, the sampling voltage is compared with the reference voltage, and after the comparison result is amplified by the error amplifying circuit, the conduction degree of the regulating tube is controlled to keep the output voltage stable.

7. The integrated power supply of claim 1, wherein the output filter circuit comprises a negative temperature coefficient NTC resistor (R12) and a twelfth inductor (L12), a twenty-second inductor (L22), the twelfth inductor (L12) and the twenty-second inductor (L22) are used for suppressing the output instantaneous current, the twelfth inductor (L12) and the twenty-second inductor (L22) are respectively installed in the positive loop and the negative loop, the negative temperature coefficient NTC resistor (R12) is installed in the positive loop circuit, and the negative temperature coefficient NTC resistor (R12) is increased or decreased according to the output instantaneous current intensity.

Technical Field

The invention belongs to power supply equipment, and particularly relates to a comprehensive power supply.

Background

The power supply circuit refers to the circuit design, the circuit form and the characteristics of a power supply part for supplying power to electric equipment. There are both ac and dc power supplies. The existing power supply circuit has single function, is suitable for certain or several electric equipment and cannot be used as a universal comprehensive power supply. In particular, in ground-specific test equipment, power needs to be supplied to various electric devices, such as: load working source, test standard source, digital analog power supply, relay working power supply box radiator fan power supply etc. at this moment, on the one hand need change the commercial power, on the other hand still need consider reliability and security, in order to satisfy special test equipment's power demand, urgently need a comprehensive power and satisfy current technical blank.

Disclosure of Invention

Aiming at the defects, the comprehensive power supply provided by the invention comprises a plurality of linear voltage-stabilized power supplies and a switching power supply which are isolated from each other and work independently, each power supply has protection of overvoltage, overcurrent, short circuit and the like, the comprehensive power supply can provide a working source, a test standard source, a digital analog power supply, a relay working power supply box cooling fan power supply and the like for equipment, the input of the comprehensive power supply is 220V/50Hz commercial power, the output of the comprehensive power supply is a multi-path direct-current voltage power supply of 4-33V, +5V, +12V, + 15V, -100V and the like, and the comprehensive power supply has the characteristics of safety and reliability in working.

In order to achieve the above purpose, the embodiment of the invention adopts the following technical scheme:

an integrated power supply, comprising a plurality of mutually isolated switching power supplies and linear power supplies, by which 220V/50Hz mains power can be converted into 4-33V, +5V, +12V, + 15V or-100V DC voltage supplies, wherein: the switch power supply comprises an input EMC suppression circuit, a rectification filter circuit, an input anti-impact circuit, a high-frequency inverter circuit, a high-frequency transformer, an output rectification filter circuit, a current and voltage sampling circuit and a drive and control protection circuit, wherein an input port of the input EMC suppression circuit is connected with 220V/50Hz commercial power, an output port of the input EMC suppression circuit is connected with an input port of the rectification filter circuit, the input anti-impact circuit is arranged in the rectification filter circuit and used for reducing the instant current during starting, an output port of the rectification filter circuit is connected with an input port of the high-frequency inverter circuit, the high-frequency transformer is arranged in the high-frequency inverter circuit as an executive device of the high-frequency inverter, an output port of the high-frequency inverter circuit is connected with an input port of the output rectification filter circuit, an output port of the output rectification, the output port of the current and voltage sampling circuit is connected with the input port of the driving and control protection circuit, and the output port of the driving and control protection circuit is connected with the control end of the high-frequency inverter circuit; the linear power supply comprises an input EMC suppression circuit, an isolation transformer, a rectification filter circuit, a linear voltage stabilizing circuit, an output filter circuit and a current and voltage sampling feedback circuit, wherein an input port of the input EMC suppression circuit is connected with 220V/50Hz mains supply, an output port of the input EMC suppression circuit is connected with a primary winding of the isolation transformer, a secondary winding of the isolation transformer is connected with an input end of the rectification filter circuit, an output end of the rectification filter circuit is connected with an input end of the linear voltage stabilizing circuit, an output end of the linear voltage stabilizing circuit is connected with an input end of the output filter circuit, an output end of the output filter circuit is connected with a direct current output port, an input port of the current and voltage sampling feedback circuit is connected with a.

Preferably, the input EMC suppression circuit comprises a varistor, a common mode inductor, an X capacitor and a Y capacitor, wherein: the common mode inductor is divided into a first inductor and a second inductor, and the first inductor and the second inductor are sequentially connected to a zero line and a live line in an alternating current circuit; the X capacitor and the Y capacitor are divided into a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor and a seventh capacitor; the second capacitor, the piezoresistor and the third capacitor are arranged at the front end of the first inductor, and the second capacitor, the piezoresistor and the third capacitor are sequentially arranged between the zero line and the live line; the fourth capacitor is arranged between the first inductor and the second inductor, and the second inductor is arranged between the zero line and the live line; the fifth capacitor, the sixth capacitor and the seventh capacitor are arranged at the rear end of the second inductor, the fifth capacitor is connected between the zero line and the live line in parallel, the sixth capacitor and the seventh capacitor are connected in series and then connected with the fifth capacitor in parallel, and the common point of the sixth capacitor and the seventh capacitor is grounded.

Preferably, the rectifying and filtering circuit in the switching power supply includes a rectifying bridge and a PFC circuit, the input protection circuit is disposed between the rectifying bridge and the PFC circuit, and the PFC circuit includes an eighth capacitor and a ninth capacitor for filtering, where: the input anti-shock circuit comprises a first resistor, a second resistor and a first relay, the first resistor and the second resistor are connected in series and then connected into the circuit, the first relay is bridged at two ends of the first resistor and the second resistor, when the control circuit drives the first relay to be disconnected, alternating current is rectified by a rectifier bridge and then limited to flow to an eighth capacitor and a ninth capacitor in the PFC circuit through the first resistor and the second resistor for charging, and when the voltage of the eighth capacitor and the ninth capacitor is charged to a threshold value, the control circuit closes the first relay.

Preferably, the high-frequency inverter circuit adopts an LLC resonant soft switching technology.

Preferably, the gate of the control MOS transistor in the output rectifying and filtering circuit is driven by a charge pump.

Preferably, the linear voltage stabilizing circuit comprises an adjusting tube, a reference voltage source, a sampling circuit and an error amplifying circuit, wherein a sampling resistor in the sampling circuit outputs sampling voltage through sampling, the sampling voltage is compared with the reference voltage, and after a comparison result is amplified by the error amplifying circuit, the conduction degree of the adjusting tube is controlled, so that the output voltage is kept stable.

Preferably, the output filter circuit comprises a negative temperature coefficient NTC resistor, a twelfth inductor and a twenty-second inductor, the twelfth inductor and the twenty-second inductor are used for suppressing the instantaneous current at the output end, the twelfth inductor and the twenty-second inductor are respectively installed in the positive loop and the negative loop, the negative temperature coefficient NTC resistor is installed in the positive loop circuit, and the negative temperature coefficient NTC resistor is selectively increased or decreased according to the intensity of the output instantaneous current.

The comprehensive power supply has the following beneficial effects:

the comprehensive power supply has the following technical characteristics: inputting 220V/50Hz commercial power and outputting a plurality of paths of direct current voltage; each path of output power supply is isolated from each other; the input and output over-voltage and under-voltage protection and the output over-current, short circuit and over-temperature protection functions are provided; the soft start technology is adopted, so that the impact current is extremely low; the single-path output fault does not influence the use of other paths of power supplies; the modularized design, safe and reliable, use and maintain convenient.

The integrated power supply has the following main functions:

the capacity of outputting 9 paths of direct current power supplies is provided; each output power supply has real-time abnormal state detection and protection functions (the abnormal state mainly comprises short circuit, overload, undervoltage, overvoltage and the like); the output voltage of the DC 4-33V power supply can be controlled by an external 0-5V analog signal; the whole body is provided with a normal (abnormal) double-color indicator lamp and an output signal end; all power supplies are mutually isolated with reference to the ground and provided with an output voltage limiting function; the power supply startup stable time is not more than 0.5S (auxiliary power supply +5V, two-way isolation).

Drawings

FIG. 1 is a schematic view of the overall structure of the present invention;

FIG. 2 is a block diagram of a switching regulator design according to the present invention;

FIG. 3 is a block diagram of a linear voltage regulator design according to the present invention;

FIG. 4 is an input EMC suppression circuit of the present invention;

FIG. 5 is an input anti-shock circuit of the present invention;

FIG. 6 shows a high frequency inverter and output rectifier circuit according to the present invention;

FIG. 7 is a waveform diagram of an LLC resonant half-bridge of the invention;

FIG. 8 is a synchronous rectification circuit in accordance with the present invention;

FIG. 9 is a waveform of gate voltage generated by the additional winding in the present invention;

FIG. 10 is a schematic diagram of a voltage regulator circuit according to the present invention;

FIG. 11 is an output filter circuit of the present invention;

FIG. 12 is a schematic front view of the present invention;

FIG. 13 is a top view of the present invention;

fig. 14 is a side view of the present invention.

Detailed Description

The invention will be further explained with reference to the accompanying drawings in which:

as shown in fig. 1, an integrated power supply includes 9 mutually isolated switching power supplies and linear power supplies, through which 220V/50Hz mains power can be converted into 4-33V, +5V, +12V, + 15V or-100V DC voltage power supplies, and the 220V mains power outputs DC power through each AC-DC module. When one module is damaged or fails, the work of other modules is not influenced. Each module has protection such as overvoltage, overcurrent and short circuit, and when a certain load is abnormal, the power module can protect itself to prevent the module from being damaged. A microprocessor and a communication module can be optionally arranged in the comprehensive power supply, and the output voltage and the load current can be monitored through an upper computer.

As shown in FIG. 2, the switching power supply comprises an input EMC suppression circuit, a rectification filter circuit, an input anti-shock circuit, a high-frequency inverter circuit, a high-frequency transformer, an output rectification filter circuit, a current-voltage sampling circuit and a drive and control protection circuit, wherein an input port of the input EMC suppression circuit is connected with 220V/50Hz commercial power, an output port of the input EMC suppression circuit is connected with an input port of the rectification filter circuit, the input anti-shock circuit is arranged inside the rectification filter circuit and used for reducing the instant current during starting up, an output port of the rectification filter circuit is connected with an input port of the high-frequency inverter circuit, the high-frequency transformer is arranged in the high-frequency inverter circuit as an executive device of the high-frequency inverter, an output port of the high-frequency inverter circuit is connected with an input port of the output rectification filter circuit, an output port, the output port of the current and voltage sampling circuit is connected with the input port of the driving and control protection circuit, and the output port of the driving and control protection circuit is connected with the control end of the high-frequency inverter circuit.

As shown in FIG. 3, the linear power supply comprises an input EMC suppression circuit, an isolation transformer, a rectification filter circuit, a linear voltage stabilizing circuit, an output filter circuit and a current and voltage sampling feedback circuit, wherein an input port of the input EMC suppression circuit is connected with 220V/50Hz mains supply, an output port of the input EMC suppression circuit is connected with a primary winding of the isolation transformer, a secondary winding of the isolation transformer is connected with an input port of the rectification filter circuit, an output port of the rectification filter circuit is connected with an input port of the linear voltage stabilizing circuit, an output port of the linear voltage stabilizing circuit is connected with an input port of the output filter circuit, an output port of the output filter circuit is connected with a DC output port, an input port of the current and voltage sampling feedback circuit is connected with a DC output port, an output port of the current and voltage sampling circuit, the isolation transformer performs voltage reduction treatment, and the alternating current converted into the alternating current with different amplitudes enters the linear voltage stabilizing circuit after being rectified and filtered. When the output voltage amplitude is large, the voltage is stabilized by adopting an adjusting tube; when the output amplitude is lower than 28V, the voltage is stabilized by adopting a special LDO chip.

It should be noted that EMC is also called electromagnetic compatibility, which refers to the ability of devices and systems to work normally in their electromagnetic environment without creating electromagnetic disturbance that cannot be borne by anything in the environment, EMC includes electromagnetic interference EMI and electromagnetic immunity EMS, and the definition includes two aspects, first, the devices should work normally in a certain electromagnetic environment, that is, the devices should have a certain electromagnetic immunity (EMS); secondly, the electromagnetic disturbance generated by the equipment cannot generate excessive influence on other electronic products, namely electromagnetic disturbance (EMI).

Wherein, switching power supply and linear power supply all include EMC suppression circuit, as shown in fig. 3, and input EMC suppression circuit includes piezo-resistor RV1, common mode inductance, X electric capacity and Y electric capacity, wherein: the common-mode inductor is divided into a first inductor L1 and a second inductor L2, and the first inductor L1 and the second inductor L2 are sequentially connected to a zero line and a live line in an alternating current circuit; the X capacitor and the Y capacitor are divided into a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6 and a seventh capacitor C7; the second capacitor C2, the piezoresistor RV1 and the third capacitor C3 are arranged at the front end of the first inductor L1, and the second capacitor C2, the piezoresistor RV1 and the third capacitor C3 are sequentially arranged between the zero line and the live line; the fourth capacitor C4 is arranged between the first inductor L1 and the second inductor L2, and the second inductor L2 is arranged between the zero line and the live line; a fifth capacitor C5, a sixth capacitor C6 and a seventh capacitor C7 are arranged at the rear end of the second inductor L2, the fifth capacitor C5 is connected between the zero line and the live line in parallel, the sixth capacitor C6 and the seventh capacitor C7 are connected in series and then connected with the fifth capacitor C5 in parallel, and the common point of the sixth capacitor C6 and the seventh capacitor C7 is grounded.

Specifically, the voltage dependent resistor mainly suppresses pulse signals such as surge voltage, lightning stroke and the like introduced from an input alternating current end, is a voltage limiting type protection device, and utilizes the nonlinear characteristic of the voltage dependent resistor, when overvoltage appears between two electrodes of the voltage dependent resistor, the voltage dependent resistor can clamp the voltage to a relatively fixed voltage value, so that the protection of a rear-stage circuit is realized. The main parameters of the varistor are: voltage dependent voltage, current capacity, junction capacitance, response time, etc.; the common mode inductor, the X capacitor and the Y capacitor form an LC filter circuit which is mainly used for inhibiting conducted interference and radiated interference.

Because alternating current needs to be connected with a large-capacity electrolytic capacitor for filtering after being rectified, at the moment of switching on the alternating current power supply, the initial voltage of the capacitor is zero, namely short circuit, the power supply can charge the capacitor with large current, and the charging current at the moment can be 10-20 times higher than the average current, so that the voltage of an alternating current power grid can be seriously interfered. In order to suppress the occurrence of such a large current surge, an anti-surge circuit needs to be connected in series between the rectifier circuit and the filter capacitor to solve this problem. The high-voltage power supply and the onboard power supply are provided with the anti-impact circuit shown in fig. 5, specifically, the rectifying and filtering circuit in the switching power supply comprises a rectifying bridge and a PFC circuit, the input anti-impact circuit is arranged between the rectifying bridge and the PFC circuit, and the PFC circuit comprises an eighth capacitor C8 and a ninth capacitor C9 for filtering, wherein: the input anti-shock circuit comprises a first resistor R1, a second resistor R2 and a first relay K1, wherein the first resistor R1 and the second resistor R2 are connected in series and then connected into the circuit, the first relay K1 is connected across the first resistor R1 and the second resistor R2 in a bridging mode, when the control circuit drives the first relay K1 to be disconnected, alternating current is rectified by a rectifier bridge and then limited to flow to an eighth capacitor C8 and a ninth capacitor C9 in the PFC circuit through the first resistor R1 and the second resistor R2 to be charged, and when voltages of the eighth capacitor C8 and the ninth capacitor C9 reach a threshold value, the control circuit closes the first relay K1.

It should be noted that, when the input ac is switched on, the ac is rectified by the rectifier bridge, then the current is limited by the resistors R1 and R2 to charge the capacitor, and when the capacitor voltage is charged to a certain value, the normally open contact of the relay K1 is switched on by the control circuit, so that the impact current caused by the capacitive load characteristic of the capacitor is reduced. In order to improve the efficiency of the whole machine and reduce the heat productivity of the power supply of the whole machine, the output rectification filtering adopts a synchronous rectification mode. After the input 220V alternating current passes through the EMC suppression circuit. And entering an anti-impact circuit, wherein the anti-impact circuit is used for reducing the instantaneous current of starting. The anti-impact current circuit outputs a bus voltage which is rectified and filtered and then serves as a high-frequency inverter circuit, and outputs a high-voltage PWM wave under the action of the PWM control circuit and the driving circuit. The high-voltage PWM wave acts on the primary side of the output transformer, and is used for isolating the input and output stages on one hand, and on the other hand, the rear-stage load is guaranteed not to influence the front-stage circuit. The secondary of the transformer is connected with a rectifying and filtering circuit to obtain 1000V high-voltage electricity, and a voltage and current acquisition circuit acquires output voltage and current in real time, so that the voltage and current acquisition circuit acts on a protection circuit on one hand and feeds back the output voltage and current to a control circuit part on the other hand to realize closed-loop voltage stabilization control.

It should be further noted that, the output power of the high-voltage power supply and the onboard power supply is not lower than 300W, so that a large capacitor is required for storing energy, and the AC-DC conversion is realized through rectification and filtering. In fig. 5, KB1 is a bridge rectifier stack, and C8 and C9 are large-capacitance filter capacitors. The rectifier bridge stack and the large-capacitance filter capacitor together obtain relatively clean direct-current voltage.

As shown in fig. 6, the high-frequency inverter circuit inverts a bus voltage (a voltage obtained by converting 220V ac into dc) into a high-frequency ac voltage, and outputs a dc signal after coupling by a transformer, thereby mainly realizing power conversion and electrical isolation. The output rectifying filter circuit is used for rectifying an alternating current signal output by the transformer into direct current voltage, filtering alternating current components by the filter circuit to obtain clean direct current, the full bridge is a power unit of the whole power supply, and the direct current is inverted into alternating current with a certain frequency or variable frequency through opening and closing of the switch. The PWM driver output signal will be switched in to the full bridge. And sampling the output signal by a sampling transformer and inputting the output signal into a PWM controller to realize voltage feedback.

Specifically, the LLC resonant soft switching circuit has the advantages that: firstly, the system works under the ZVS condition in the whole load range (including light load), thereby realizing high efficiency; the working frequency variation range is narrow, so that the design of a high-frequency transformer and an input filter is facilitated; the voltage stress of the switch used at the primary side is clamped on the input voltage, and the voltage of the two diodes at the secondary side is always equal to twice of the output voltage of the center-tapped transformer. Therefore, the conduction loss of a single switching tube and the primary copper loss of a single transformer are reduced, and the efficiency is effectively improved.

The main operating waveforms of the LLC resonant half bridge are shown in fig. 7. In the figure, Vgs1 and Vgs2 are driving waveforms of Q1 and Q2 respectively, Ir is an inductor current waveform of a resonant inductor Lr, Im is a current waveform of a leakage inductor Lm of a transformer, Id1 and Id2 are waveforms of a secondary side output rectifying diode respectively, and Ids1 is a conduction current of Q1, and the waveform diagram is divided into 6 stages according to different working states.

The synchronous rectification circuit adopts an improved topological structure, as shown in fig. 8, the synchronous rectification circuit is used for generating driving signals of VF1 and VF2 by using gate voltages of VF1 and VF2 from input capacitors C1 and C2, and input and output voltages of the driving circuit are shown in fig. 9. The grid of the control MOS tube in the output rectifying and filtering circuit adopts the driving mode of a charge pump. The synchronous rectification working process is as follows:

1) period 0 to t 0: in the period, both Ut1 and Ut2 are in positive half cycles, Ut2= Ut2m, and VD4 is positively biased to be on, and VD3 is reversely biased to be off. Ut2 charges capacitor Cl through VD4 and capacitor C2 is clamped by the forward voltage drop of VD 4. After the charging is finished, Ug1= Ut2m-Ud > Ut, Ug2= -Ud, where Ud is the conduction voltage drop of VD4, and at this time, VF1 is conducted in the reverse direction, and VF2 is blocked in the forward direction.

2) time period t 0-t 1: and Ut2=0 in the period, VD3 and VD4 are cut off, the capacitor Cl discharges to the capacitor C2 until the voltages on the two capacitors are equal, and Ug1= Ug2= Ut2m-Ud = Usb > Ut. Since both Ug1 and Ug2 are higher than Ut, both VF1 and VF2 are in the on state, and L releases energy to maintain the load current continuous.

3) time period t 1-t 2: in the period, UT2= -UT2m, VD3 is conducted in the forward direction, VD4 is conducted in the reverse bias mode, Ut2 charges a capacitor C2 through VD3, UT2m-UD = Usa > Ut after charging is finished, Ug1= -Ud, VF1 is blocked in the forward direction, and VF2 is conducted in the reverse direction.

4) time period t 2-t 3: during the time period Ut2=0, VD3 and VD4 are both turned off, and the capacitor C2 discharges to C1 until the voltages on the two capacitors are equal, then Ug1= Ug2= Ut2m-Ud = Usb > Ut. Since both Ug1, Ug2 are higher than Ut, both VF1 and VF2 are in the on state, and L releases energy to maintain the load current continuous.

Through the synchronous rectification technology, under the heavy current output state, the rectification loss is effectively reduced, the overall efficiency of the power supply is improved, and the size of the power supply module is reduced.

In this embodiment, the high voltage power supply and the onboard power supply both use a dedicated PWM control chip UCC28950, and the control IC is a new product that optimizes functions, improves functions, and exits on the basis of the industry standard of UCCx895 series phase shift controllers of TI corporation, and provides the highest frequency and conversion efficiency for the present power supply system with high performance requirements. UCC28950 employs advanced full-bridge control and aggressive synchronous rectifier output control, the primary signal is allowed to become delayed to ensure ZVS is operating properly over a wide range of load currents and input voltages, and the load currents naturally adjust the secondary synchronous rectifier switching delay time, ultimately maximizing efficiency.

Specifically, the linear voltage-stabilizing power supply enters an isolation transformer for voltage reduction after passing through an EMC suppression circuit, and is input into the linear voltage-stabilizing power supply after being rectified. Considering the overall heat dissipation of the linear power supply, the input voltage amplitude of each linear power supply needs to be considered, and the input voltage amplitude should be ensured to be close to the output voltage +3V as much as possible.

As shown in fig. 10, the linear voltage stabilizing circuit includes an adjusting tube, a reference voltage source, a sampling circuit and an error amplifying circuit, wherein a sampling resistor in the sampling circuit outputs a sampling voltage by sampling, the sampling voltage is compared with the reference voltage, and after a comparison result is amplified by the error amplifying circuit, the conduction degree of the adjusting tube is controlled to keep the output voltage stable. At the moment, the adjusting tube works in an amplifying region, when the output voltage changes, the feedback voltage also changes, the adjusting tube is changed to the same degree, and the output voltage is dynamically adjusted. For low voltage output power, a special LDO chip may be used.

As shown in fig. 11, in order to ensure that the ripple noise of the output signal is as small as possible, reduce the crosstalk between the power supply and the load, and isolate the influence of the load on the power supply, an EMC suppression circuit is designed at the output end of the power supply. The output filter circuit comprises a negative temperature coefficient NTC resistor R12, a twelfth inductor L12 and a twenty-second inductor L22, wherein the twelfth inductor L12 and the twenty-second inductor L22 are used for suppressing the instantaneous current of the output end, the twelfth inductor L12 and the twenty-second inductor L22 are respectively installed in a positive loop and a negative loop, the negative temperature coefficient NTC resistor R12 is installed in the positive loop circuit, and the negative temperature coefficient NTC resistor R12 is selectively increased or decreased according to the intensity of the output instantaneous current.

The shell of the integrated power supply is subjected to conductive oxidation treatment, and the structure edges and corners are blunt. The alternating current input interface adopts a standard computer power socket form, the input interface is provided with a fuse box, a fuse tube is easy to replace, meanwhile, a manual switch is installed on one side of the power line interface, and a multistage filter is arranged in the alternating current input. As shown in fig. 12, 13, and 14, the appearance of the integrated power supply is schematically illustrated, and in order to ensure that the power supply has good heat dissipation characteristics, a metal housing is used, and the metal housing is subjected to conductive oxidation treatment, and meanwhile, the housing is integrally formed, so that the heat dissipation area of the power supply is increased. In order to fully ensure the transportation condition, the power weighing piece is reinforced (such as glue pouring, fastening screws and the like).

It should be noted that, the power supply adopts fan forced air cooling, and when in use, only the fan needs to be kept track of whether the fan rotates, so that the semiconductor elements in the power supply are prevented from being damaged and aged due to over-temperature, and the service life of the power supply is prolonged. Meanwhile, the main circuit board of the power supply is subjected to three-proofing treatment, so that the power supply can work well in a humid environment. The internal structure of the power supply system enhances the anti-vibration capability, all the direct-insertion elements are subjected to glue dispensing treatment, and all the screws are fixed by adopting thread fastening glue.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.