CN208353236U - Synchrotrans realize isolated passive self-powered optocoupler three-phase synchronous rectification circuit - Google Patents

Abstract

A kind of isolated passive self-powered optocoupler three-phase synchronous rectification circuit of synchrotrans realization belongs to rectification circuit field；Including including three-phase synchronous rectification circuit, optical coupling isolation circuit, synchrotrans, AC power source and load；The three-phase synchronous rectification circuit includes metal-oxide-semiconductor Q1, Q2, Q3, Q4, Q5 and Q6；The synchrotrans include transformer T and three-phase synchronous transformer M；The optical coupling isolation circuit includes optocoupler D1, D2, D3, D4, D5 and D6 of same model；The ac power output is separately connected synchrotrans, three-phase synchronous rectification circuit and optical coupling isolation circuit, the synchronous transformation connects optical coupling isolation circuit, the optical coupling isolation circuit connects three-phase synchronous rectification circuit, the three-phase synchronous rectification circuit connection load；The utility model keeps trigger signal accurately reliable, improves rectification circuit stability, avoids dedicated single chip microcomputer driving circuit, simplifies control loop, reduces cost.

Description

Synchrotrans realize isolated passive self-powered optocoupler three-phase synchronous rectification circuit

Technical field

The utility model belongs to rectification circuit field more particularly to a kind of synchrotrans realize isolated passive self-powered light Coupling three-phase synchronous rectification circuit.

Background technique

Currently, the continuous improvement and new material more and more deep, scientific and technical with the energy-saving and emission-reduction policy of country It is developed, people increasingly pay attention to the raising of efficiency, and as the equipment of big power consumption, motor is also got over using the ratio of frequency converter timing Come higher.Frequency converter is the controlling electric energy that power frequency supply is transformed to another frequency using the on-off action of power semiconductor device The electric energy of AC power source is converted to direct current first by device, frequency converter, then is the alternating current of changeable frequency direct current Electrical change It is loaded to drive, the rectifier diode of rectification circuit is replaced using power MOSFET, gives full play to the low spy of its on state resistance Point can greatly reduce rectifier loss, to improve power-efficient.MOSFET tube device is rectified for rectifier diode Success or failure key is that can the trigger signal to MOSFET tube device synchronous with three-phase input voltage, and when synchronous rectification is most important Be for synchronous rectification control signal accurate reliable control.

According to the working principle of rectified three-phase circuit it is found that the angle of flow of each MOSFET pipe is answered in a complete cycle Less than or equal to 120 °, according to three-phase alternating current electrical characteristics, i.e. the rule of natural commutation point, AC signal is once changed every 60 ° Phase, and no matter when need to guarantee that upper bridge arm and lower bridge arm can only have a pipe conducting, if occurring two in the same set A or more than two pipes simultaneously turn on, it will lead to the catastrophe failures such as the phase fault of net side, make the MOSFET of commutating circuit Puncture and can not work, the reliable and stable important prerequisite item that is to ensure that commutating circuit and can work normally of synchronous triggering signal Part.

Summary of the invention

The utility model provides a kind of synchrotrans and realizes in view of the above-mentioned problems, overcome the deficiencies in the prior art Isolated passive self-powered optocoupler three-phase synchronous rectification circuit.

The technical solution of the utility model includes:

A kind of isolated passive self-powered optocoupler three-phase synchronous rectification circuit of synchrotrans realization, including three-phase synchronous rectification Circuit, optical coupling isolation circuit, synchrotrans, AC power source and load；The three-phase synchronous rectification circuit include metal-oxide-semiconductor Q1, Q2, Q3, Q4, Q5 and Q6；The synchrotrans include transformer T and three-phase synchronous transformer M；The optical coupling isolation circuit packet Include optocoupler D1, D2, D3, D4, D5 and D6 of same model；The ac power output is separately connected synchrotrans, three-phase Circuit of synchronous rectification and optical coupling isolation circuit, the synchronous transformation connect optical coupling isolation circuit, the optical coupling isolation circuit connection Three-phase synchronous rectification circuit, the three-phase synchronous rectification circuit connection load.

It further, further include the first voltage stabilizing element, the second voltage stabilizing element, third voltage stabilizing element, the 4th voltage stabilizing element, Five voltage stabilizing elements and the 6th voltage stabilizing element；First voltage stabilizing element includes resistance R31 and zener diode DZ1, and described second Voltage stabilizing element includes resistance R32 and zener diode DZ2, and the third voltage stabilizing element includes resistance R33 and zener diode DZ3, the 4th voltage stabilizing element include resistance R34 and zener diode DZ4, and the 5th voltage stabilizing element includes resistance R35 and pressure stabilizing Diode DZ5, the 6th voltage stabilizing element includes resistance R36 and zener diode DZ6；One end of the resistance R31 and pressure stabilizing The emitter of the cathode connection optocoupler D1 output end of diode DZ1, and connect with the grid of Q1, the other end of resistance R31 and surely Press the input terminal a of the anode connection commutating circuit of diode DZ1；One end of the resistance R32 and the cathode of zener diode DZ2 The emitter of optocoupler D2 output end is connected, and is connect with the grid of Q2, the other end of resistance R32 and the sun of zener diode DZ2 The negative output terminal N of pole connection rectification output loop；It is defeated that one end of resistance R33 with the cathode of zener diode DZ3 connects optocoupler D3 The emitter of outlet, and connect with the grid of Q3, the other end of resistance R33 is connected with the anode of zener diode DZ3 to be rectified back The input terminal b on road；One end of resistance R34 connects the emitter of optocoupler D4 output end, and and Q4 with the cathode of zener diode DZ4 Grid connection, the other end of resistance R34 connects the input terminal c of commutating circuit with the anode of zener diode DZ4；Resistance R35 One end the emitter of optocoupler D5 output end is connected with the cathode of zener diode DZ5, and connect with the grid of Q5, resistance R35 The other end connected with the anode of zener diode DZ5 rectification output loop negative output terminal N；One end of resistance R36 and pressure stabilizing The emitter of the cathode connection optocoupler D6 output end of diode DZ6, and connect with the grid of Q6, the other end of resistance R36 and surely Press the negative output terminal N of the anode connection rectification output loop of diode DZ6.

Further, the AC power source be 220V, the AC power source after transformer T, respectively with optocoupler D4, The diode cathode of D6, D2 are connected with the diode cathode of optocoupler D1, D3, D5, and the net of the rectified three-phase circuit is surveyed and three-phase Synchrotrans M is connected, the current collection of the triode of the output end and optocoupler D4, D6, D2, D1, D3, D5 of three-phase synchronous transformer M Pole passes through resistance R24, resistance R26, resistance R22, resistance R21, resistance R23 respectively and connects with resistance R25.

Further, the three-phase synchronous rectification circuit is connected using three-phase bridge rectifier circuit mode, three phase rectifier electricity The low-voltage coil of the input terminal connection transformer T on road, output end of the output end of transformer T as three-phase synchronous transformer M.

Further, the cathode connection metal-oxide-semiconductor Q1 of the anode of the optocoupler D1 input terminal diode, D4 input terminal diode Source electrode and metal-oxide-semiconductor Q4 drain electrode, the anode of optocoupler D3 input terminal diode, D6 input terminal diode cathode connect metal-oxide-semiconductor The drain electrode of the source electrode and metal-oxide-semiconductor Q6 of Q3, the anode of optocoupler D5 input terminal diode, the cathode of D2 input terminal diode connect MOS The cathode of the drain electrode of the source electrode and metal-oxide-semiconductor Q2 of pipe Q5, optocoupler D1, D3, D5 input terminal diode passes through resistance R40 connection optocoupler The anode of D2, D4, D6 input terminal diode；The grid of the emitter connection metal-oxide-semiconductor Q1 of optocoupler D1 output end, optocoupler D2 output end Emitter connection metal-oxide-semiconductor Q2 grid, optocoupler D3 output end emitter connection metal-oxide-semiconductor Q3 grid, optocoupler D4 output end Emitter connection metal-oxide-semiconductor Q4 grid, optocoupler D5 output end emitter connection metal-oxide-semiconductor Q5 grid, optocoupler D6 output end Emitter connection metal-oxide-semiconductor Q61 grid；The grid of metal-oxide-semiconductor Q2, Q4, Q6 pass through the second voltage stabilizing element, the 4th pressure stabilizing member respectively Part, the 6th voltage stabilizing element are connected with the source level of metal-oxide-semiconductor Q2, Q4, Q6, and the source level of metal-oxide-semiconductor Q2, Q4, Q6 link together；Metal-oxide-semiconductor The grid of Q1, Q3, Q5 pass through the first voltage stabilizing element respectively, third voltage stabilizing element, the 5th voltage stabilizing element and metal-oxide-semiconductor Q1, Q3, Q5's Source level is connected.

The utility model has the advantages that compared with the existing technology

The utility model realizes that metal-oxide-semiconductor trigger signal is synchronous with AC-input voltage using optocoupler, is believed using single phase ac Number zero crossing or three-phase ac signal natural commutation point control optocoupler internal diode on-off, to drive inside optocoupler The on-off of triode realizes that circuit of synchronous rectification provides the synchronous rectification driving control signal with isolation features for MOSFET, Synchronization is provided for the outlet side of optocoupler also by synchrotrans while alternating current input power supplying provides power supply to rectification major loop Power supply influences the on-off of triode inside optocoupler by the on-off and AC power source of diode simultaneously, optocoupler light emitting diode With the common participation of synchronizing voltage device, duplicate protection can be provided to the generation of synchronization signal.Keep trigger signal accurately reliable, improves Rectification circuit stability, avoids dedicated single chip microcomputer driving circuit, simplifies control loop, reduces cost, cancels optocoupler External power supply power supply, realizes passive drive, solves the problems, such as that synchronous commutating control circuit is complicated and control signal reliability is low.

Detailed description of the invention

Fig. 1 is the structure diagram of the utility model.

Fig. 2 is transformer T circuit diagram.

Fig. 3 is three-phase synchronous transformer M circuit diagram.

Fig. 4 is the circuit diagram of the utility model.

Specific embodiment

The utility model is described in detail below with reference to attached drawing.

Specific embodiment one

The isolated passive self-powered optocoupler three-phase synchronous rectification circuit of a kind of synchrotrans realization, as shown in Figure 1, including three Be synchronised rectification circuit, optical coupling isolation circuit, synchrotrans, AC power source and load；The three-phase synchronous rectification circuit packet Include metal-oxide-semiconductor Q1, Q2, Q3, Q4, Q5 and Q6；The synchrotrans include transformer T and three-phase synchronous transformer M；The optocoupler Isolation circuit includes optocoupler D1, D2, D3, D4, D5 and D6 of same model；The ac power output is separately connected synchronous change Depressor, three-phase synchronous rectification circuit and optical coupling isolation circuit, the synchronous transformation connect optical coupling isolation circuit, the light-coupled isolation Circuit connection three-phase synchronous rectification circuit, the three-phase synchronous rectification circuit connection load.

The course of work: by the power MOSFET tube of same model as rectifying device in three-phase synchronous rectification circuit, optocoupler every Trigger signal is generated by the optocoupler of same model from circuit, controls optocoupler internal diode using the natural commutation point of AC signal On-off provide the synchronous rectification with isolation features to drive the on-off of triode inside optocoupler for circuit of synchronous rectification Driving control signal, while exchange supplies electricity to power supply while rectification major loop provides signal also by synchrotrans to optocoupler Input terminal provides power supply signal, to control the on-off of triode inside optocoupler, make the on-off of triode inside optocoupler simultaneously by The on-off of diode and the influence of ac signal, the common participation of optocoupler light emitting diode and synchronizing voltage device, can also be right The generation of synchronization signal provides duplicate protection, keeps trigger signal accurately reliable, improves rectification circuit stability.

The trigger circuit of the patent No. 20520398658.2 is made of diode rectifier bridge, optocoupler and power module of voltage regulation, no External power supply module is only needed, and is difficult to realize accurate synchronization, while the reverse recovery characteristic extender that diode is intrinsic The part turn-off time will lead to transformer short-circuit, and control precision is low, poor reliability, so this patent considers isolated passive self-powered Optocoupler synchronizes trigger circuit to replace diode to form, to improve the rectification reliability of entire circuit.

Specific embodiment two

Specifically, as shown in figure 4, further including the first voltage stabilizing element, the second voltage stabilizing element, third voltage stabilizing element, the 4th steady Press element, the 5th voltage stabilizing element and the 6th voltage stabilizing element；First voltage stabilizing element includes resistance R31 and zener diode DZ1, Second voltage stabilizing element includes resistance R32 and zener diode DZ2, and the third voltage stabilizing element includes resistance R33 and pressure stabilizing Diode DZ3, the 4th voltage stabilizing element include resistance R34 and zener diode DZ4, and the 5th voltage stabilizing element includes resistance R35 With zener diode DZ5, the 6th voltage stabilizing element includes resistance R36 and zener diode DZ6；One end of the resistance R31 The emitter of optocoupler D1 output end is connected with the cathode of zener diode DZ1, and is connect with the grid of Q1, and resistance R31's is another End connects the negative output terminal N of rectification output loop with the anode of zener diode DZ1；One end of the resistance R32 and pressure stabilizing two The emitter of the cathode connection optocoupler D2 output end of pole pipe DZ2, and connect with the grid of Q2, the other end of resistance R32 and pressure stabilizing The negative output terminal N of the anode connection rectification output loop of diode DZ2；One end of resistance R33 and the cathode of zener diode DZ3 The emitter of optocoupler D3 output end is connected, and is connect with the grid of Q3, the other end of resistance R33 and the sun of zener diode DZ3 The negative output terminal N of pole connection rectification output loop；It is defeated that one end of resistance R34 with the cathode of zener diode DZ4 connects optocoupler D4 The emitter of outlet, and connect with the grid of Q4, it is defeated that the other end of resistance R34 connects rectification with the anode of zener diode DZ4 The negative output terminal N in circuit out；One end of resistance R35 connects the emitter of optocoupler D5 output end with the cathode of zener diode DZ5, And connect with the grid of Q5, the other end of resistance R35 connects the negative output of rectification output loop with the anode of zener diode DZ5 Hold N；One end of resistance R36 connects the emitter of optocoupler D6 output end with the cathode of zener diode DZ6, and connects with the grid of Q6 It connects, the other end of resistance R36 connects the negative output terminal N of rectification output loop with the anode of zener diode DZ6.

Specific embodiment three

Specifically, as shown in Fig. 2, the AC power source be 220V, the AC power source after transformer T, respectively with The diode cathode of optocoupler D4, D6, D2 are connected with the diode cathode of optocoupler D1, D3, D5, and the net of the rectified three-phase circuit is surveyed It is connected with three-phase synchronous transformer M, the output end of three-phase synchronous transformer M and the triode of optocoupler D4, D6, D2, D1, D3, D5 Collector pass through resistance R24, resistance R26, resistance R22, resistance R21, resistance R23 respectively and connected with resistance R25, be optocoupler The triode of D4, D6, D2, D1, D3 and D5 are powered, to control the energization of triode electric power loop.

Specific embodiment four

Specifically, the three-phase synchronous rectification circuit is connected using three-phase bridge rectifier circuit mode, rectified three-phase circuit Input terminal connection transformer T low-voltage coil, output end of the output end of transformer T as three-phase synchronous transformer M.

Specific embodiment five

Specifically, as shown in figure 3, the cathode of the anode of the optocoupler D1 input terminal diode, D4 input terminal diode connects Connect the drain electrode of the source electrode and metal-oxide-semiconductor Q4 of metal-oxide-semiconductor Q1, the cathode of the anode of optocoupler D3 input terminal diode, D6 input terminal diode Connect the drain electrode of the source electrode and metal-oxide-semiconductor Q6 of metal-oxide-semiconductor Q3, the yin of the anode of optocoupler D5 input terminal diode, D2 input terminal diode Pole connects the drain electrode of the source electrode and metal-oxide-semiconductor Q2 of metal-oxide-semiconductor Q5, and the cathode of optocoupler D1, D3, D5 input terminal diode passes through resistance R40 Connect the anode of optocoupler D2, D4, D6 input terminal diode；The grid of the emitter connection metal-oxide-semiconductor Q1 of optocoupler D1 output end, optocoupler The grid of the emitter connection metal-oxide-semiconductor Q2 of D2 output end, the grid of the emitter connection metal-oxide-semiconductor Q3 of optocoupler D3 output end, optocoupler The grid of the emitter connection metal-oxide-semiconductor Q4 of D4 output end, the grid of the emitter connection metal-oxide-semiconductor Q5 of optocoupler D5 output end, optocoupler The grid of the emitter connection metal-oxide-semiconductor Q61 of D6 output end；The grid of metal-oxide-semiconductor Q2, Q4, Q6 pass through the second voltage stabilizing element respectively, the Four voltage stabilizing elements, the 6th voltage stabilizing element are connected with the source level of metal-oxide-semiconductor Q2, Q4, Q6, and the source level of metal-oxide-semiconductor Q2, Q4, Q6 are connected to one It rises；The grid of metal-oxide-semiconductor Q1, Q3, Q5 pass through the first voltage stabilizing element, third voltage stabilizing element, the 5th voltage stabilizing element and metal-oxide-semiconductor respectively The source level of Q1, Q3, Q5 are connected.

First voltage stabilizing element, the second voltage stabilizing element, third voltage stabilizing element, the 4th voltage stabilizing element, the 5th voltage stabilizing element Play stabilization with emitter output voltage of the 6th voltage stabilizing element to optocoupler output, improve metal-oxide-semiconductor Q1, Q2, Q3, Q4, The stability of Q5 and Q6 grid voltage.

Specific embodiment six

When transformer T is connected, three-phase synchronous rectification circuit is in running order, bridge arm on metal-oxide-semiconductor Q1, Q3, Q5 composition, Metal-oxide-semiconductor Q4, Q6, Q2 form lower bridge arm, and the low-voltage coil end of transformer T generates three-phase alternating current and is sent into three-phase synchronous rectification electricity Road, according to the characteristic of three-phase alternating current, synchronization can make and only make two optocoupler conductings, such as a certain moment of three-phase alternating current When a phase voltage maximum, b phase voltage minimum, the secondary side winding method of synchrotrans is utilized to can guarantee that the output of V1 and V6 incudes Potential makes the transistor collector reliable power supply of D1 and D6 work, while electric current flows into optocoupler D1 input terminal diode from a point Anode, then flowed out from the cathode of optocoupler D1 input terminal diode, the diode current flow of optocoupler D1, while three poles of optocoupler D1 at this time Optocoupler D1 is connected under the excitation of V1 power supply in the collector of pipe, generates G1 gate pole trigger signal, and then metal-oxide-semiconductor Q1 triggering is led Logical, then electric current flows into the anode of optocoupler D6 input terminal diode, then the cathode from optocoupler D6 input terminal diode through resistance R40 Outflow, and optocoupler D6 is connected under the excitation of V6 power supply in the collector of the triode of optocoupler D6, generates G6 gate pole triggering letter Number, then metal-oxide-semiconductor Q6 triggering and conducting forms current loop so that metal-oxide-semiconductor Q1, Q6 be made to simultaneously turn on as load RL power supply.

Utilize triode inside the on-off and optocoupler of the natural commutation point control optocoupler internal diode of three-phase ac signal The on-off of triode inside optocoupler is carried out while being driven to the presence or absence of collector supply pumping signal, is not required to photoelectric coupled circuit external additional Power supply, due to it avoids and was caused in the past in natural commutation point to the power supply of optocoupler inside transistor collector since diode is solid because always Some reverse recovery characteristics extend the device turn-off time and cause bridge arm or lower bridge arm simultaneously there are two metal-oxide-semiconductor conducting to Make transformer short-circuit.The common participation of optocoupler light emitting diode and synchrotrans can provide the generation of synchronization signal double It protects again.It is synchronous with three-phase input voltage to further realize metal-oxide-semiconductor trigger signal, using three-phase synchronous rectification principle, optocoupler every Can be according to the phase conduction of three-phase alternating current from optocoupler D1-D6 in circuit, i.e., bridge arm, lower bridge arm respectively have one on synchronization Metal-oxide-semiconductor simultaneously turns on, and provides the synchronous rectification driving control signal with isolation features for three-phase synchronous rectification circuit, makes to trigger Signal is accurately reliable, improves rectification circuit stability, avoids dedicated single chip microcomputer driving circuit, simplifies control loop, Reduce cost.

Due to the simplification of control loop, the circuit of synchronous rectification modularization of optocoupler self-powered can both be can be applied to high frequency Switching Power Supply can also be integrated in the inside of alternating current generator, and the accessory power supply of optocoupler self-driving circuit is by rectification circuit The synchronized transformer of input terminal provides, and synchronous with rectifier bridge holding, then optocoupler self-powered does not need additional power supply power supply, from And realize passive, it effectively prevents the intrinsic reverse recovery characteristic of diode and extends the device turn-off time and cause transformer short Road.Optocoupler interior light emitting diodes are to the detection of natural commutation point and synchrotrans to optocoupler inside triode power supply Switching can provide duplicate protection to the output of synchronously control driving signal.

Above embodiments are exemplary description of this patent, do not limit its protection scope, those skilled in the art Member can also be changed its part, as long as it does not exceed the essence of this patent, within the protection scope of the present patent.

Claims (5)

1. a kind of synchrotrans realize isolated passive self-powered optocoupler three-phase synchronous rectification circuit, which is characterized in that including three Be synchronised rectification circuit, optical coupling isolation circuit, synchrotrans, AC power source and load；The three-phase synchronous rectification circuit packet Include metal-oxide-semiconductor Q1, Q2, Q3, Q4, Q5 and Q6；The synchrotrans include transformer T and three-phase synchronous transformer M；The optocoupler Isolation circuit includes optocoupler D1, D2, D3, D4, D5 and D6 of same model；The ac power output is separately connected synchronous change Depressor, three-phase synchronous rectification circuit and optical coupling isolation circuit, the synchronous transformation connect optical coupling isolation circuit, the light-coupled isolation Circuit connection three-phase synchronous rectification circuit, the three-phase synchronous rectification circuit connection load.

2. synchrotrans realize isolated passive self-powered optocoupler three-phase synchronous rectification circuit according to claim 1, special Sign is, further includes the first voltage stabilizing element, the second voltage stabilizing element, third voltage stabilizing element, the 4th voltage stabilizing element, the 5th voltage stabilizing element With the 6th voltage stabilizing element；First voltage stabilizing element includes resistance R31 and zener diode DZ1, the second voltage stabilizing element packet Resistance R32 and zener diode DZ2 are included, the third voltage stabilizing element includes resistance R33 and zener diode DZ3, the 4th pressure stabilizing Element includes resistance R34 and zener diode DZ4, and the 5th voltage stabilizing element includes resistance R35 and zener diode DZ5, institute Stating the 6th voltage stabilizing element includes resistance R36 and zener diode DZ6；One end of the resistance R31 and the yin of zener diode DZ1 Pole connects the emitter of optocoupler D1 output end, and connect with the grid of Q1, the other end of resistance R31 and zener diode DZ1's The input terminal a of anode connection commutating circuit；It is defeated that one end of the resistance R32 with the cathode of zener diode DZ2 connects optocoupler D2 The emitter of outlet, and connect with the grid of Q2, it is defeated that the other end of resistance R32 connects rectification with the anode of zener diode DZ2 The negative output terminal N in circuit out；One end of resistance R33 connects the emitter of optocoupler D3 output end with the cathode of zener diode DZ3, And connect with the grid of Q3, the other end of resistance R33 connects the input terminal b of commutating circuit with the anode of zener diode DZ3；Electricity One end of resistance R34 connects the emitter of optocoupler D4 output end with the cathode of zener diode DZ4, and connect with the grid of Q4, electricity The other end of resistance R34 connects the input terminal c of commutating circuit with the anode of zener diode DZ4；One end of resistance R35 and pressure stabilizing two The emitter of the cathode connection optocoupler D5 output end of pole pipe DZ5, and connect with the grid of Q5, the other end of resistance R35 and pressure stabilizing The negative output terminal N of the anode connection rectification output loop of diode DZ5；One end of resistance R36 and the cathode of zener diode DZ6 The emitter of optocoupler D6 output end is connected, and is connect with the grid of Q6, the other end of resistance R36 and the sun of zener diode DZ6 The negative output terminal N of pole connection rectification output loop.

3. synchrotrans realize isolated passive self-powered optocoupler three-phase synchronous rectification circuit according to claim 2, special Sign is, the AC power source is 220V, the AC power source after transformer T, respectively with two poles of optocoupler D4, D6, D2 Pipe cathode is connected with the diode cathode of optocoupler D1, D3, D5, and the net of the three-phase synchronous rectification circuit is surveyed and three-phase synchronous transformation Device M is connected, and the output end of three-phase synchronous transformer M leads to respectively with the collector of the triode of optocoupler D4, D6, D2, D1, D3, D5 Resistance R24, resistance R26, resistance R22, resistance R21, resistance R23 is crossed to connect with resistance R25.

4. synchrotrans realize isolated passive self-powered optocoupler three-phase synchronous rectification circuit according to claim 3, special Sign is, the three-phase synchronous rectification circuit is connected using three-phase bridge rectifier circuit mode, three-phase synchronous rectification circuit it is defeated Enter the low-voltage coil of end connection transformer T, output end of the output end of transformer T as three-phase synchronous transformer M.

5. synchrotrans realize isolated passive self-powered optocoupler three-phase synchronous rectification circuit according to claim 4, special Sign is, the anode of the optocoupler D1 input terminal diode, the source electrode of the cathode connection metal-oxide-semiconductor Q1 of D4 input terminal diode and The drain electrode of metal-oxide-semiconductor Q4, the anode of optocoupler D3 input terminal diode, the cathode of D6 input terminal diode connect the source electrode of metal-oxide-semiconductor Q3 With the drain electrode of metal-oxide-semiconductor Q6, the anode of optocoupler D5 input terminal diode, the cathode of D2 input terminal diode connect the source of metal-oxide-semiconductor Q5 The cathode of the drain electrode of pole and metal-oxide-semiconductor Q2, optocoupler D1, D3, D5 input terminal diode is defeated by resistance R40 connection optocoupler D2, D4, D6 Enter to hold the anode of diode；The grid of the emitter connection metal-oxide-semiconductor Q1 of optocoupler D1 output end, the emitter of optocoupler D2 output end connect The grid of metal-oxide-semiconductor Q2, the grid of the emitter connection metal-oxide-semiconductor Q3 of optocoupler D3 output end are connect, the emitter of optocoupler D4 output end connects The grid of metal-oxide-semiconductor Q4, the grid of the emitter connection metal-oxide-semiconductor Q5 of optocoupler D5 output end are connect, the emitter of optocoupler D6 output end connects Connect the grid of metal-oxide-semiconductor Q61；The grid of metal-oxide-semiconductor Q2, Q4, Q6 pass through the second voltage stabilizing element respectively, and the 4th voltage stabilizing element, the 6th is steady Pressure element is connected with the source level of metal-oxide-semiconductor Q2, Q4, Q6, and the source level of metal-oxide-semiconductor Q2, Q4, Q6 link together；Metal-oxide-semiconductor Q1, Q3, Q5's Grid passes through the first voltage stabilizing element, third voltage stabilizing element respectively, and the 5th voltage stabilizing element is connected with the source level of metal-oxide-semiconductor Q1, Q3, Q5.