CN101340143B

CN101340143B - Switch converter of high power factor

Info

Publication number: CN101340143B
Application number: CN2008103030997A
Authority: CN
Inventors: 马丽娟
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-11-30
Filing date: 2008-07-25
Publication date: 2011-01-12
Anticipated expiration: 2028-07-25
Also published as: CN101340143A

Abstract

The invention relates to a switch converter with a higher power factor, the converter is characterized in that: the correction of the power factor is completed at the same time of the voltage conversion, the problem of increased voltage of an energy storage capacitor is solved, power switches M1 and M2 can work at a zero voltage state (ZVS) and a zero current state (ZCS), the M1 and M2 can simultaneously drive a transformer T and an inductor Lpfc, the transformer T, a leakage inductor Lr, the inductor Lpfc and a capacitor can be connected in parallel or in series to form a serial-parallel network, when the Lpfc is connected with the Lr or transformer T in series, the function of the Lpfc can be completed by the leakage inductor Lr or the transformer T, thereby saving one inductor which is more expensive and costs; and the characteristics leads the switch converter to become a practical circuit structure.

Description

Switch converter of high power factor

Technical field

The present invention is a kind of switch converters with high power factor, belongs to field of power electronics.

Background technology

The mode that at present typical switch converters adopts full-bridge rectification to add electric capacity changes the input AC electricity into direct current.The power factor of this mode is about 0.6, has higher harmonic component, brings very big pollution to electrical network.Therefore add power factor emendation function in increasing area and the national requirements converter, to reduce the pollution of switch converters to electrical network.Mostly traditional converter that has power factor correction is two-step scheme, uses two controllers, and a voltage and an input current that is used for controlling on the storage capacitor makes input current follow the variation of input voltage, becomes sinusoidal wave; Another is used for the output voltage of control change device, makes it to keep constant.This converter has very high power factor and good output characteristic, but complex structure, the cost height, and power is through twice processing, and power density is low.Referring to accompanying drawing 1: prior art 1.

Occurred single-level power factor correction (PFC) converter that structure is simple, cost is low, power density is high in recent years, it can be realized simultaneously to the correction of input current waveform with to the adjustment of output voltage.In this converter, have only a controller, shared device for power switching is so have comparatively simple circuit configuration and lower cost.Referring to accompanying drawing 2: prior art 2.But the subject matter of sort circuit is:

1, the voltage of storage capacitor is subjected to the influence of load, when voltage exceeds the ability to bear of electric capacity, components and parts damage accident can take place.

2, the voltage stress of device for power switching is big, and switching loss is big, and heating is serious.

Summary of the invention

The present invention proposes a kind of succinct circuit framework, can realize power factor correction (PFC) function, finish the function of voltage transformation simultaneously, and the voltage of storage capacitor is superelevation not, approximate the output voltage of traditional full-bridge rectification filtering, device for power switching can be operated in no-voltage (ZVS) and zero current (ZCS) on off state, ZVS, ZCS can make the loss of device for power switching alleviate, heating reduces, electromagnetic interference (EMI) descends, and these characteristics make the present invention become very practical circuit framework.

To achieve these goals, the present invention includes: diode D1, D2, D9, D10, storage capacitor C5, capacitor C 1, C2, C9, C10 and diode D1, D2, D9, the D10 parallel connection, the source electrode of power switch M1 be connected in storage capacitor C5 two ends after the drain electrode of M2 is connected, capacitor C 8 is connected with inductance L pfc, connect with transformer T again, in this series arm, inductance L pfc can be replaced by the leakage inductance Lr of transformer T, the output winding of transformer T connects rectifying and wave-filtering device or balancing network, for load provides suitable voltage or electric current, referring to Fig. 3: the first embodiment of the present invention, Ta1, Tb1, Tb2 is the different windings of transformer T, above-mentioned inductance L pfc and transformer T, capacitor C 8, components and parts such as C6 have multiple connected mode, for example connect with C8 after Lpfc and the T parallel connection again; Lpfc only connects with C8, increases C6 in addition and connects with transformer T; Lpfc connects or the like with C8, C6, referring to second embodiment of the invention, the 3rd embodiment, the 4th embodiment, the 5th embodiment, the 6th embodiment, the 7th embodiment with after T is in parallel again.Be familiar with these professional personnel and on the basis of this thinking, also can make multiple circuit distortion, still belong to category of the present invention.These converters can be single channel output, also can be multichannel output; Direct current output can be provided, also can provide to exchange output, but also both and deposit.

Characteristics of the present invention are: the series-parallel network that above-mentioned capacitor C 8, C6, inductance L pfc, transformer T form always has an end and exchanges end (AC) and link.Diode D1, D2, D9, D10 participate in energy storage and the exergonic process of capacitor C 8, capacitor C 6, transformer T, leakage inductance Lr, inductance L pfc directly, are not only from dc terminal: i.e. storage capacitor C5 absorbs energy.Be stored in the magnetization energy of energy and the transformer T of capacitor C 8, C6, leakage inductance Lr, inductance L pfc, a part is to circulate between capacitor C 8, C6, Lr, Lpfc, T, a part passes to load by transformer T, has only the sub-fraction unloading in capacitor C 5 the insides, and capacitor C 5 releases energy when power switch M1 or M2 conducting, so the voltage of C5 does not uprise.D1, D2, D9, D10 work on off state, can reach the effect that improves power factor like this.When the parameter of the series-parallel network that constitutes as C8, C6, Lpfc, transformer T was fit to, M1, M2 just can be operated in no-voltage (ZVS) and zero current (ZCS) on off state.

Description of drawings

Fig. 1: prior art 1

Fig. 2: prior art 2

Fig. 3: first embodiment of the invention circuit diagram

Fig. 4-1: operating state 1

Fig. 4-2: operating state 2

Fig. 4-3: operating state 3

Fig. 4-4: operating state 4

Fig. 5: the voltage of first embodiment of the invention key point, current waveform

Fig. 6: second embodiment of the invention circuit diagram

Fig. 7: third embodiment of the invention circuit diagram

Fig. 8: fourth embodiment of the invention circuit diagram

Fig. 9: fifth embodiment of the invention circuit diagram

Figure 10: sixth embodiment of the invention circuit diagram

Figure 11: seventh embodiment of the invention circuit diagram

Figure 12: eighth embodiment of the invention circuit diagram

Figure 13: ninth embodiment of the invention circuit diagram

Figure 14: tenth embodiment of the invention circuit diagram

Figure 15: eleventh embodiment of the invention circuit diagram

Embodiment

Fig. 3 first embodiment of the invention.Ta1, Tb1, Tb2 are the different windings of isolating transformer T.Lr is the leakage inductance of this transformer, and Lr colonizes in transformer inside, also can use outside independent inductance.D7, D8 can be external diodes, also can be the body diodes of M1, M2.M1, M2 can be field effect transistor (Mos), also can be the power devices of other type, for example triode etc.C0 provides the high frequency channel of each course of work.AC is an input ac power.

Method of attachment is: diode D1, D2, D9, D10 are connected ac input end, and capacitor C 5 is used for stored energy.Capacitor C 1, C2, C9, C10 and diode D1, D2, D9, D10 are in parallel.The switching speed that C1, C2, C9, C10 can slow down diode D1, D2, D9, D10 has reduced the EMI noise.The source electrode of power switch M1 be connected in storage capacitor C5 two ends after the drain electrode of M2 is connected.Capacitor C 8 is connected with inductance L pfc, connects with transformer T again.In this example, the function of inductance L pfc is finished by leakage inductance Lr, saves a PFC inductance (Lpfc).Output winding Tb1, the Tb2 of transformer T connects rectifying and wave-filtering device or balancing network, for load provides suitable voltage or electric current.M1, M2 are Mos pipes, also can be the switching devices of other type such as triode.Rectifier diode also can adopt the mode of synchronous rectification.The output of transformer T can have a plurality of windings, exports different voltages, satisfies the unequally loaded requirement.Analyze for convenient, herein only for example with single channel output.

Fig. 4-1, Fig. 4-2, Fig. 4-3, Fig. 4-4 have pointed out the crucial course of work, are concrete analysis below:

During the positive half cycle of AC:

Operating state 1, Fig. 4-1: M2 conducting in this state, M1 turn-offs, and AC side electric energy through power switch M2, diode D2, is finished energy storage and excitation process by the former limit winding Ta1 and the leakage inductance Lr of capacitor C 8, transformer.

Operating state 2, Fig. 4-2: M1, M2 all turn-off in this state, and the energy of winding Ta1 and leakage inductance Lr is transferred to C5 by D8, D10, and the D8 conducting means that M1 is can no-voltage (ZVS) open-minded.

Operating state 3, Fig. 4-3: M2 turn-offs in this state, the M1 conducting, the energy storage of Ta1 and Lr is shifted to C5 by M1, D10, and after the energy of Lr discharged and finishes, capacitor C 8 was given the reverse excitation of Ta1, Lr by D9, M1, storage capacitor C5 gives Ta1, Lr excitation once more by M1 simultaneously.

Operating state 4, Fig. 4-4: M1, M2 all turn-off in this state, and the energy storage of winding Ta1 and leakage inductance Lr is transferred to C5 by C8, D9, D7, and the D7 conducting means that M2 is can no-voltage open-minded.

The course of work during AC negative half period is similar during to positive half cycle.

Fig. 5 is voltage, the current waveform of first embodiment of the invention key point.

1 first row I (AC) is the high frequency waveforms of input current, ignores the burr of near zero-crossing point, and as can be seen: its envelope is approximately sine wave shape, and phase place is consistent with input voltage.

2 second row V (AC) and V (C5) are the contrasts of ac input voltage and storage capacitor C5 voltage, and as can be seen: the voltage of storage capacitor C5 is approximately equal to the crest voltage of input voltage, does not have the extra-high pressure phenomenon.

3 the third lines are drive waveforms of power switch M1, M2, represent with different amplitudes, so that distinguish.

4 fourth line I (D9) are the current waveforms of a diode in the rectifier bridge, and as can be seen: the electric current that flows through rectifier bridge is a high-frequency current.

5 fifth line Id (M2) are the current waveforms that flows through M2, and as can be seen: power switch M2 is no-voltage (ZVS) conducting, and when M2 turn-offed, the electric current that flows through M2 had begun to descend, and illustrate that M2 will be operated in zero current (ZCS) on off state under the condition that is fit to.

Fig. 6 is the second embodiment of the present invention, increases capacitor C 6 in this example, increases capacitor C 6 and can make the voltage at C5 two ends more stable, and the power output of converter increases.

Fig. 7 is the third embodiment of the present invention, has increased the inductance L pfc in the series arm in this example, its objective is that to make the technique for coiling of transformer T simpler.

Fig. 8 is the fourth embodiment of the present invention, and the PFC inductance L pfc in this example is in parallel with transformer T and leakage inductance Lr, and purpose is to reduce the influence of transformer T to the thermal energy storage process of Lpfc, can make power factor better.

Fig. 9 is the fifth embodiment of the present invention, and being increases C6 on the basis of the 4th embodiment, can make to make the voltage at C5 two ends more stable, and the power output of converter is bigger.

Figure 10 is the sixth embodiment of the present invention, and transformer T connects with C6 in this example, PFC inductance L pfc connects with C8, and not contact makes transformer T and PFC inductance L pfc influence each other littler like this in the middle of two series arms.Make the adjusting of power factor convenient, power output is bigger.

Figure 11 is the seventh embodiment of the present invention, the capacitor C 11 that adds in this example, and when transactional analysis, the C8 of equivalent second embodiment of the invention; The capacitor C 12 that adds in this example is when transactional analysis, and the C6 of equivalent second embodiment of the invention can make the rated voltage drop by half of C6.

Figure 12 is the eighth embodiment of the present invention, and the load in this example is an AC characteristic, and load is connected to by voltage, current balance type network above the output winding of isolating transformer, for example gaseous discharge lamp, ultrasonic unit etc.

Figure 13 is the ninth embodiment of the present invention, is input as three-phase alternating current in this example.

Figure 14 is a tenth embodiment of the invention, Ta, Tb is two windings of isolating transformer T, Lr is the leakage inductance of this transformer, Lr colonizes in transformer inside, but also can use outside independent inductance, D7, D8 can be external diode, also can be M1, the body diode of M2, M1, M2 can be field effect transistor (Mos), also can be the power device of other type, triode for example, coupling method is: former limit winding Ta one end connects the alternating current AC of input, and capacitor C 1 is in parallel with diode D1, and capacitor C 2 is in parallel with diode D2, diode D1, the D2 series connection, mid point connects the other end of former limit winding; The source electrode of switching tube M1 is connected with the drain electrode of M2, and mid point connects the other end of AC power supplies; The negative electrode of D1 links to each other with the drain electrode of M1, connects the positive pole of C5 again; The anode of D2 links to each other with the source electrode of M2, connects the negative pole of C5 again; The secondary winding Tb of transformer T connects rectifier diode D3, D4, D5, D6, connects load through behind the filter capacitor, if load does not need rectification or filtering, also can omit the process of rectifying and wave-filtering.As from the foregoing: transformer T both had been connected in the work loop of PFC, be connected in the work loop of isolated converter again, that is: transformer T had both participated in power factor correction (PFC) process, had also participated in the process of isolation voltage conversion, can save the PFC energy storage inductor of a costliness like this.This example is compared simpler with top each example, but the voltage at C5 two ends is higher.

Figure 15 is an eleventh embodiment of the invention, in this example, Ta1, Ta2, Tb is the different windings of isolating transformer (T), Lr-a1 is the leakage inductance of Transformer Winding Ta1, Lr-a2 is the leakage inductance of Transformer Winding Ta2, D7, D8 can be external diode, also can be M1, the body diode of M2, M1, M2 can be field effect transistor (Mos), also can be the power device of other type, for example triode etc., wherein, Ta1, Ta2 can regard as the Transformer Winding Ta of first embodiment of the invention split and obtains, and Ta1 inserts the PFC loop then, and Ta2 inserts the isolated converter loop.This example is compared with the tenth example, can reduce the voltage at C5 two ends.

Below only being that some specific embodiment is specifically introduced, is not that the present invention is done any type of restriction, and any those skilled in the art all can utilize said method and content to make multiple change, conversion, still belong in the scope of technical solution of the present invention.

Claims

1. the switch converters with high power factor is characterized in that,

First diode (D1), second diode (D2), the 9th diode (D9), the tenth diode (D10) constitute rectification and freewheeling circuit, connected mode is that the anode of first diode (D1) is connected with the negative electrode of second diode (D2), the anode of the 9th diode (D9) is connected with the negative electrode of the tenth diode (D10), form two series arms, the anode of second diode and the tenth diode is connected to form common oedoeagus again, and the negative electrode of first diode and the 9th diode is connected to form common cloudy end again;

First electric capacity (C1), second electric capacity (C2), the 9th electric capacity (C9), the tenth electric capacity (C10) are respectively with first diode (D1), second diode (D2), the 9th diode (D9), (D10) is in parallel for the tenth diode;

The source electrode of first power switch (M1) is connected with the drain electrode of second power switch (M2), the source electrode of the drain electrode of first power switch (M1) and second power switch (M2) is connected respectively to the positive pole and the negative pole of storage capacitor (C5), and the positive pole of storage capacitor (C5) and negative pole are connected to the common cloudy end of above-mentioned rectification and freewheeling circuit and are total to oedoeagus;

The former limit winding of PFC inductance (Lpfc), transformer (T), the 8th electric capacity (C8) and the 6th electric capacity (C6) constitute the LC network, one end of LC network connects the ac input end of switch converters, the other end of this LC network is connected on the node that the drain electrode series connection of the source electrode of first power switch (M1) and second power switch (M2) forms, wherein, the PFC inductance is parasitic leakage inductance of transformer itself or the outside independent inductance that is provided with;

The output winding of transformer (T) connects rectifying and wave-filtering device or balancing network, for load provides suitable voltage or electric current.

2. the switch converters with high power factor according to claim 1 is characterized in that, there are following four kinds of connected modes in described LC network:

Mode 1:PFC inductance (Lpfc) only connect with the 8th electric capacity (C8) with after the former limit winding of transformer (T) is in parallel, the 6th electric capacity (C6) omission;

Mode 2:PFC inductance (Lpfc) is connected with the 8th electric capacity (C8), and the former limit winding of transformer (T) is connected with the 6th electric capacity (C6);

Mode 3:PFC inductance (Lpfc) is connected with the 8th electric capacity (C8), the 6th electric capacity (C6) with after the former limit winding of transformer (T) is in parallel simultaneously;

Mode 4: the former limit winding of transformer (T) is connected with the 8th electric capacity (C8), the 6th electric capacity (C6) simultaneously, and PFC inductance (Lpfc) is the leakage inductance of transformer.

3. the switch converters with high power factor according to claim 1 is characterized in that, this LC network makes first power switch, second power switch work in zero voltage switch (ZVS) state and Zero Current Switch (ZCS) state when parameter is fit to.

4. the switch converters with high power factor according to claim 1, it is characterized in that, this converter is single channel output or multichannel output, it provides and exchanges output or direct current output or interchange and export both with direct current and deposit the rectifying and wave-filtering device employing diode rectification or the synchronous rectification of this converter.

5. the switch converters with high power factor according to claim 1, it is characterized in that, first electric capacity (C1), second electric capacity (C2), the 9th electric capacity (C9), the tenth electric capacity (C10) are respectively with first diode (D1), second diode (D2), the 9th diode (D9), (D10) is in parallel for the tenth diode, can slow down the switching speed of first diode (D1), second diode (D2), the 9th diode (D9), the tenth diode (D10), reduce the EMI noise.