CN1312614A - Electronic switch transition process softening techn utilizing additional coupled winding - Google Patents

Abstract

The present invention discloses a technology for softening electronic switch trasient process by using additional coupling winding generally used in general current transformer. Unlike other buffer and soft switch technology, it utilizes an additional coupling winding on the inductance element of current transformer, isolation diode and capacitor and discharge resistor with high resistance valve to form series-connection resonance when the switch is turned on by means of leakage inductance and capacitor to make absorption capacitor can resonate to feed energy under the condition of no producing circulating current to use simple quick energy conversion mode to obvisouly reduce defect of electronic switch turn-on and turn-off traisent process.

Description

Technology with the softening electronic switch transient process of additional coupling winding

The present invention relates to technology, be different from existing various buffer technology and soft switch technique, belong to electrician's subject, power electronics branch field with the softening electronic switch transient process of additional coupling winding.

By retrieval as can be known: the main power electronic technology periodical of domestic in recent years and IEEE, domestic and international famous relevant academic meeting paper collection all do not have to find and " with the technology of the additional softening electronic switch transient process of winding that is coupled " similar buffer technology and similar soft switch circuit.

The pulse chopping Semiconductor Converting Technology is the core of modern power electronics technology, and it constitutes the firm power convertor circuit in conjunction with high frequency all-controlling power electronics device and burst length ratio modulation control technology, is applied to various convertor assemblys.But, in the pulse chopping convertor circuit, owing to exist inductance, capacitance energy storage element and circuit to have distributed capacitance, lead-in inductance, device parasitic capacitance in the circuit, transformer leakage inductance etc., in speed-sensitive switch unsteady flow process, unavoidably there is the switch transient process, the voltage or the electric current of unusual high amplitude takes place; Because the desirable electronic switch of the right and wrong of power electronic device own, also have switch transit time, power electronic device is in this transient process like this, and the height that certainly exists its voltage waveform and current waveform overlaps, this overlapping adds high amplitude voltage or the electric current under the transient state, by switch power loss P _TExpression formula (1) knows that this switching loss is very big.At electric and electronic technical field, claim that this pulse chopping mode is the hard switching circuit.

$P_T=\frac{1}{T}\underset{\mathrm{\Δt}}{\∫}u\left(t\right)i\left(t\right)\mathrm{dt}$ , T is the switch work period, Δ t is the switch transient state time; (1)

The hard switching circuit causes that the loss of pulse chopping convertor circuit is big, electromagnetic interference is serious, reliability reduces, and along with the raising of switch operating frequency, this phenomenon is even more serious.For this reason, must be in Power Electronic Circuit adjunction buffer circuit (snubber).The adding of buffer circuit has changed the switch working point track of electronic power switch device, make its significantly minimizing of overlapping part of voltage waveform, current waveform during transition, and make the energy of transient process that the place of releasing arranged, reduced transient voltage, current peak significantly.Buffer technology is a kind of makeshift, though it has reduced the switching loss of electronic power switch device, improved the device functional reliability, but it is just transferred to this loss on the power resistor of buffer circuit, can not reduce the switching loss of convertor circuit at all, must force Power Limitation the application of high-power circuit.

Now, for energy-conservation, development for the support information technology, for the automation and the electromechanical integration of higher degree, social an urgent demand electronic power conversion device has higher efficient, better Electro Magnetic Compatibility, lower cost, higher operating frequency to be to obtain littler volume and weight.In order to reach above-mentioned target, people propose many new technologies to overcome the defective of buffer circuit.Domestic and international at present work in this respect can be divided into two big approach.One is improvement property method, and it is on the buffer technology basis, changes the mode of releasing of transient state energy, manages lossy buffer circuit is changed into loss-free buffer circuit; Its two way that discards tradition for proposing is in recent years constructed novel circuit topology, the hard switching circuit is changed into the revolutionary new method of soft switch (softswitch) circuit.The former wants additional diode, power inductor, capacitor, on traditional buffer circuit basis, remove power consumption resistance, with the electric field energy on the absorption capacitor, when opening, switching tube is converted to the magnetic energy of additional electrical sensor again, this magnetic energy feeds back to input voltage source or load in next off-phases with this energy, to constitute the very low buffer circuit of loss; Its property class is the same with traditional buffer circuit, can only solve switch and turn-off or open the buffering in one of them stage in two transient state stages, and the realization of transient state stage (as turn-offing) buffering is to be cost with the hard switching effect that increases another transient state stage (as open-minded), if the both will realize loss-free buffering, then circuit is quite complicated, the high electric current supplementary load loss that exist energy repeatedly to produce during feedback in addition, and depend on condition of work and the very difficult defectives such as comfort cushioning effect that under the different operating condition, obtain.The latter is then in order to overcome the former defective, the auxiliary active electric power electronic switching device that perhaps utilize to increase, diode, power inductor, capacitor etc., select suitable auxiliary control circuit, constitute auxiliary active resonance converter circuit, perhaps under the constraints of forceful electric power road, increase power inductor, capacitor etc., with special control method, make switching tube all be operated in no-voltage or zero current condition, switch is turn-offed or open two transient state stages and can both realize switch power loss minimum at each switch transient state transition period.Obviously, these two kinds of methods have all increased cost, volume, weight because of increasing power component etc.Generally speaking, the former cost is big, and effect is good inadequately, though the latter is better than the former on effect, except cost is bigger, also because of obstructed usefulness and the complexity that increased circuit and control, has been subjected to very big restriction so apply.And, in fact so-called lossless be non-existent, electric current flows in components and parts, must be accompanied by the certain power loss, all there is the repeatedly transmission of energy in above-mentioned two kinds of methods, therefore have loss inevitably.The complexity of this external circuit and control has also been brought the raising of cost and the reduction of reliability.For this reason, seek the better substitute technology or the more superior general soft switch circuit of cost performance of traditional buffer circuit, be the hot topic research and development problem of electric and electronic technical field always.

The object of the invention is that it is by means of one on the current transformer inductance element additional coupling winding, isolation diode and capacitor and high value discharge resistance, when opening, switch constitutes series resonance by leakage inductance and capacitor, make absorption capacitor produce resonance energy regenerative under the circulation hardly, significantly alleviate electronic switch in simple and direct power conversion mode and opened and turn-offed the defective of transient process, and proposed the technology that a kind of novel additional coupling of usefulness winding softens the electronic switch transient process.

Technical scheme of the present invention is: at the main electrode two ends of electronic power switch pipe S1 in parallel one by isolating with speed-sensitive switch diode D1, the DC series circuit that high frequency is noninductive absorption capacitor C1 forms, the connection of isolating diode D1 be make its positive polarity and electronic power switch pipe S1 positive pole on line towards identical (to power MOSFET tube, make the positive pole of the drain electrode of S1 and D1 the most close exactly, IGBT is managed, make the positive pole of the collector electrode of S1 and D1 the most close exactly), here (being Fig. 1) is exactly that positive pole with isolating diode D1 is connected with the positive pole of electronic power switch pipe S1, the negative pole of D1 is connected with capacitor C1 one end, the negative pole of another termination S1 of C1, the negative pole of electronic power switch pipe S1 also is connected to the negative pole of input voltage source, the public point of the series circuit that is made of D1 and C1 is connected to another and isolates a end with speed-sensitive switch diode D2, the connection of isolating diode D2 constitutes the forward tandem-type connection for making itself and D1, the negative pole that is D1 is the most close with the positive pole of D2 on line, here be exactly that negative pole with D1 is connected with the positive pole of D2, the other end of D2 is connected to an end of the RC circuit of being made up of high-frequency isolation capacitor C2 and resistor R 1 in parallel, the negative pole that is D2 here is connected with RC circuit in parallel, the other end that C2 is in parallel with R1, be connected on the additional coupling winding L a of high frequency transformer TX1, the former limit winding L p of TX1 is exactly the original former limit of a current transformer winding, Ls is original limit winding of current transformer, additional coupling winding L a and the shared magnetic core of Lp, La is identical with the umber of turn of Lp, it is that the polarity of the induced potential of La when the S1 conducting is connected with the polarity formation forward of D2 that the connection of La requires, make the charged electric potential of C1 and the induced potential of La on circuit, constitute the electromotive force stack, the non-same polarity (do not have and beat * point end) that is La here is connected with the other end of R1 parallel connection with C2, the other end of La, be that end of the same name (beating * point end) is in parallel with the end of the same name (beating * point end) of the former limit of TX1 winding L p, be connected to input voltage source V1 positive pole jointly, the non-same polarity of Lp (do not have and beat * point end) is connected to the positive pole of switching tube, the end of the same name of La is in parallel with the end of the same name of the former limit of TX1 winding L p, be connected to the input voltage source positive pole jointly, with the induced potential that guarantees above-mentioned La correct polarity is arranged, like this for original convertor circuit, the component parameter requirement that is increased partly is, i.e. selection to Fig. 1 circuit parameter is that the power capacity of La is C1U _S1 ²F/2, U _S1Be the ceiling voltage of electronic switching tube S1 when turn-offing, f is the converter switches frequency, the turn ratio of La and Lp is 1, the value of high frequency is noninductive absorption capacitor C1 should be chosen the transient state magnetic energy that is added in when can basic absorption S1 turn-offing on the switching tube S1, voltage when switching tube is turn-offed, current waveform (working point track) obviously staggers, lap is minimum, high frequency capacitor C2 typical case value is more than the twice of C1, resistor R 1 typical value is 1/2.2C2f, be that the electric energy that C2 should guarantee C1 is absorbed all is transferred to input source by C2, stay on the C2 on the load circuit of inferior limit Ls and partly, the electric charge that R1 should will remain on the C2 in the switch one-period is released substantially, so that the voltage on the C2 is very low, reach and be no more than 1/10th of the last charging voltage of original C1, its foundation is to the RC circuit, its time constant is about 2.2 o'clock electric charges on the capacitor and has discharged substantially, with do not add any buffering and compare with the basic converter circuit of soft switch circuit, Fig. 1 circuit only increases C1, C2, D1, D2, R1 reaches five elements of additional coupling winding L a with the shared magnetic core of the original high frequency transformer TX1 of current transformer, these components and parts all are smaller power, just can under lowest loss, finish the absorption of inductance transient state magnetic field energy when turn-offing, capacitive field can discharge under the LC series resonance of TX1 leakage inductance Lleak and C=C1C2/ (C1+C2) composition input source when opening, and because C2, R1 is to the buffer action of DC circuit, on this inductance element, do not produce tangible electric current circulation, the loss of not obvious increase inductance element does not significantly strengthen turn-on consumption yet; In addition since the absorption of these energy with discharge all electronic switch open and turn-off that two dynamic processes finish, thereby do not influence the work of current transformer steady-state process.

This technology is common to general converter circuit, can solve the circuit defect problem that electronic power switch produces in opening and turn-off two transient process with minimum additional passive components and parts, the simplest and the most direct power conversion form, least cost cost, less supplementary load loss mode.

In the above description:

Fig. 1 is the basic circuit diagram of the present invention that is proposed.

Fig. 2 is the equivalent circuit diagram of Fig. 1 circuit when electronic switch S1 opens.

Fig. 3 is the equivalent circuit diagram of Fig. 1 circuit when electronic switch S1 turn-offs.

The basic circuit diagram that Fig. 4 uses in the DC converter output circuit for the present invention.

The basic circuit diagram that Fig. 5 uses in two-tube converter circuit for the present invention.

Fig. 6 is the Computer Simulation oscillogram of Fig. 1 circuit.

It goes to realize the requirement of softening electronic switch transient process with technical method cleverly.Its basic circuit is seen Fig. 1, and Fig. 1 opens equivalent circuit Fig. 2 and Fig. 3 with blocking interval at electronic switch.Ia is the equivalent current of additional energy regenerative circuit among Fig. 2, and Lleak is the equivalent leakage inductance of transformer, has also indicated the sense of current of circuit among the figure.Know that thus its know-why is on traditional RCD type buffer circuit basis, remove the high power discharge resistance R of power consumption, also needn't the secondary power inductor, but by the coupling of the small-power on the inductance element that is attached in current transformer winding L a, when the umber of turn of the umber of turn of La and Lp is identical, according to the Faraday's electromagnetic induction law in the physics, the auxiliary coupling winding of this and the shared magnetic core of original inductance element has produced induced potential when the switching tube conducting, the value VLa of this induced potential equals input source voltage V1, the polarity of this induced potential is that the electromotive force on the capacitor C1 that makes after this induced potential and the energy storage forms the electromotive force stack, to have the inductance magnetic field energy that will produce when absorb turn-offing transient state with this electromotive force is converted to voltage on the charging capacitor C1 of electric field energy function and brings up to and be higher than input source voltage, be exactly that the energy level of electric field energy is improved by energy, utilize the buffer action of capacitor C2 and high resistance measurement R1, being enough to not form substantially on inductance element electric current loop flows down, this electric field energy is discharged to input voltage source V1 and output loading with the charge discharge form, be different from traditional loss-free buffer circuit, the release of this electric field energy is to constitute the formed resonance current of series resonance with inductor leakage inductance Lleak and absorption capacitor, resonance current flows to input voltage source V1 or passes to load by transformer with SIN function amount form when electronic switching tube is opened, the characteristics of SIN function amount are that amplitude is an initial point with zero, increase gradually, L and C value are very little, therefore harmonic period is very short, does not only enlarge markedly opening of switching tube and shoves but also make the opening process of electronic switch softening.Discharge resistance R1 is used for the charge discharging resisting on the isolating capacitor C2 is fallen, because resistance is higher, own loss is lower.Utilization is connected in parallel on absorption capacitor on electronic power switch pipe transient state magnetic field energy when absorbing switching tube and disconnecting inductor, be converted to the electric field energy that is stored in the absorption capacitor, the roughly the same traditional RCD type of this process buffer circuit, but owing to the low-loss discharge process that has thereafter, so the capacity of absorption capacitor can be got greatly, be turn-offed the buffering purpose preferably to reach.Be not subjected under the converter operating infulence with this simplest passive soft buffering method, also can not influence under the converter steady-state working condition, only in the simplest switch periods, utilize and turn-off or open two transient state stages, just can reach softening two transient process of turn-offing and open simultaneously, realize effectively utilizing the purpose of transient state energy with minimum additional components and parts, the simplest and the most direct power conversion form, least cost cost, less supplementary load loss mode.From optimizing angle, this technology has high performance-price ratio.Compare with traditional RCD type buffer circuit, the Power Resistor that the soft buffer circuit of this kind need not consume energy, and only increase the auxiliary winding of a small-power and prevent the isolating diode of electric current circulation and the discharge resistance of isolating capacitor and smaller power.But point out this technology can not deal with problems the electronic power switch pipe self that is not very serious parasitic capacitance open the effect problem of shoving.Fig. 6 is exactly the Computer Simulation oscillogram of basic circuit Fig. 1 of the present invention's proposition.The voltage, the current waveform that have shown electronic switching tube S1 in Fig. 6 know easily that therefrom the invention new technology that Fig. 1 uses can reach the softening requirement of turn-offing and opening two transient process simultaneously.Also shown the current waveform by C2 and R1 in Fig. 6, known easily that therefrom the electric energy of C1 mainly arrives input source and time limit Ls circuit by the C2 energy regenerative, the electric energy of R1 loss seldom.So Fig. 1 has embodied the invention characteristics that can solve the circuit defect problem that electronic power switch produces with minimum additional passive components and parts, the simplest and the most direct power conversion form, least cost cost, less supplementary load loss mode in opening and turn-off two transient process.

Because the basic circuit that the present invention proposes only relates to input voltage source and inductance element, general current transformer all contains these two parts, so can think that this invention technology is a kind of current techique.The technical method of invention proposition is generalized on the general current transformer according to this, and its concrete exemplifying embodiment is seen Fig. 1, Fig. 5, Fig. 6.

Fig. 1 is applicable to single tube converter circuit and half-bridge converter circuit.Fig. 1 expansion is obtained Fig. 6, it is applicable to the multitube converter circuit, as double tube positive exciting formula circuit, full bridge circuit, low side electronic switching tube S1 and the peripheral component D1 thereof that be connected with the negative pole of input voltage source V1 this moment, D2, C1, C2, same Fig. 1 of connection of the non-same polarity of the non-same polarity of the former limit winding L p of R1 and high frequency transformer TX1 and additional coupling winding L a, additional coupling winding L a is identical with the umber of turn of Lp, here the components and parts that increased are S2, C3, D3, their connection is the positive pole that the positive pole of high-end electronic switching tube S2 is met input voltage source V1, the end reconfiguration of the same name of the former limit winding L p of high frequency transformer TX1 is on the negative pole of high-end electronic switching tube S2, on this contact, also be connected with the negative pole of isolating with speed-sensitive switch diode D3, the positive pole of diode D3 connects the end of the noninductive absorption capacitor C3 of high frequency, the end of the same name of additional coupling winding L a also is connected with the positive pole of D3, the other end of absorption capacitor C3 is connected with the positive pole of high-end electronic switching tube S2, be exactly that the polarity of the induced potential that additional coupling winding L a produces during with the synchronous conducting of S2 at electronic power switch pipe S1 is connected with the polarity formation forward of isolating diode D2 like this, make the charged electric potential of capacitor C1 and C3 on circuit, constitute the electromotive force stack with the additional induced potential that is coupled winding L a, can finish two synchronous working switching tube S1 simultaneously with minimum additional components and parts like this, the requirement of the softening transient process of S2.

Fig. 1 expansion is obtained Fig. 5, it is applicable to the DC converter output circuit, as single-ended forward formula DC converter half-wave output circuit, both-end DC converter all-wave output circuit, the electronic power switch pipe S1 of Fig. 1 is replaced with sustained diode 3, and with output inductor L0 replacement high frequency transformer TX1, additional coupling winding L a and the shared magnetic core of L0, constitute coupling inductor L0, the original winding of L0 is as the former limit winding L p of coupling inductor, additional coupling winding L a is identical with the umber of turn of Lp, the non-same polarity of Lp links together with the additional non-same polarity that is coupled winding L a and together is connected on the positive pole of output loading end, the polarity of the induced potential that additional coupling winding L a produces when sustained diode 3 conductings is connected with the polarity formation forward of isolating diode D2, make the charged electric potential of capacitor C1 constitute the electromotive force stack with the additional induced potential that is coupled winding L a on circuit, the energy regenerative direction is that output loading R0 is held.

Claims (3)

1. soften the technology of electronic switch transient process with additional coupling winding, it is characterized in that: at the main electrode two ends of electronic power switch pipe (S1) isolating diode (D1) in parallel, the DC series circuit that the noninductive absorption capacitor of high frequency (C1) is formed, the connection of isolating diode (D1) for the positive pole that makes its anodal and electronic power switch pipe (S1) on line towards identical, the positive pole of isolating diode (D1) is connected with the positive pole of electronic power switch pipe (S1), the negative pole of isolating diode (D1) is connected with capacitor (C1) end, the negative pole of another termination electronic power switch pipe (S1) of capacitor (C1), the negative pole of electronic power switch pipe (S1) is also to the negative pole of input voltage source (V1), be connected to an end of the speed-sensitive switch isolating diode (D2) of another isolation usefulness by the isolating diode (D1) and the public point of the series circuit of capacitor (C1) formation, the connection of isolating diode (D2) constitutes the forward tandem-type connection for making itself and isolating diode (D1), the negative pole that is isolating diode (D1) is the most close with the positive pole of isolating diode (D2) on line, the negative pole of isolating diode (D1) is connected with the positive pole of isolating diode (D2), the negative pole of isolating diode (D2) is connected to an end of the RC circuit of being made up of high-frequency isolation capacitor (C2) and resistor (R1) in parallel, the negative pole of isolating diode (D2) is connected with RC circuit in parallel, the high-frequency isolation capacitor (C2) and resistor (R1) other end in parallel, be connected on the non-same polarity of additional coupling winding (La) of high frequency transformer (TX1), former limit winding (Lp) of transformer (TX1) is exactly the original former limit of a current transformer winding, (Ls) be original limit winding of current transformer, additional coupling winding (La) and the shared magnetic core in former limit winding (Lp), the end of the same name of additional coupling winding (La) is in parallel with the end of the same name of transformer (TX1) former limit winding (Lp), be connected to input voltage source (V1) positive pole jointly, the non-same polarity of former limit winding (Lp) is connected to the positive pole of switching tube (S1), with the induced potential that guarantees above-mentioned additional coupling winding (La) correct polarity is arranged, additional coupling winding (La) is identical with the umber of turn of former limit winding (Lp), it is to make the polarity of adding the induced potential of coupling winding (La) when electronic power switch pipe (S1) conducting form forward with the polarity of isolating diode (D2) to be connected that the connection of additional coupling winding (La) requires, and makes the charged electric potential of capacitor (C1) and the additional induced potential that is coupled winding (La) constitute the electromotive force stack on circuit.

2. the technology of the softening electronic switch transient process of the additional coupling of usefulness according to claim 1 winding, it is characterized in that: be used for the multitube convertor circuit, the low side electronic switching tube (S1) and the peripheral component (D1) thereof that are connected with the negative pole of input voltage source (V1), isolating diode (D2), capacitor (C1), high-frequency isolation capacitor (C2), the non-same polarity of the former limit winding (Lp) of resistor (R1) and high frequency transformer (TX1) is constant with the connection of the non-same polarity of additional coupling winding (La), additional coupling winding (La) is identical with the umber of turn of former limit winding (Lp), the components and parts that increased are high-end electronic switching tube (S2), absorption capacitor (C3), diode (D3), their connection is the positive pole that the positive pole of high-end electronic switching tube (S2) is met input voltage source (V1), the end reconfiguration of the same name of the former limit winding (Lp) of high frequency transformer (TX1) is on the negative pole of high-end electronic switching tube (S2), on this contact, also be connected with the negative pole of isolating with speed-sensitive switch diode (D3), the positive pole of diode (D3) connects an end of the noninductive absorption capacitor of high frequency (C3), the end of the same name of additional coupling winding (La) also is connected with the positive pole of (D3), the other end of absorption capacitor (C3) is connected with the positive pole of high-end electronic switching tube (S2), be exactly to make the polarity of the induced potential that additional coupling winding (La) produces during with high-end electronic switching tube (S2) conducting synchronously at electronic power switch pipe (S1) form forward to be connected like this, make the charged electric potential of capacitor (C1) and absorption capacitor (C3) on circuit, constitute electromotive force and superpose with the induced potential that adds the winding (La) that is coupled with the polarity of isolating diode (D2).

3. the technology of the softening electronic switch transient process of the additional coupling of usefulness according to claim 1 winding, it is characterized in that: the output circuit that is used for DC converter, electronic power switch pipe (S1) replaces with fly-wheel diode (D3), and with output inductor (L0) replacement high frequency transformer (TX1), additional coupling winding (La) and (L0) shared magnetic core, constitute coupling inductor (L0), the original winding of coupling inductor (L0) is as the former limit winding (Lp) of coupling inductor, additional coupling winding (La) is identical with the umber of turn of former limit winding (Lp), the non-same polarity of former limit winding (Lp) links together with the additional non-same polarity that is coupled winding (La) and together is connected on the positive pole of output loading end (R0), the polarity of the induced potential that additional coupling winding (La) produces when fly-wheel diode (D3) conducting is connected with the polarity formation forward of isolating diode (D2), make the charged electric potential of capacitor (C1) constitute the electromotive force stack with the additional induced potential that is coupled winding (La) on circuit, the energy regenerative direction is that output loading (R0) is held.

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