CN1089409A

CN1089409A - Six-phase non-feedback inversion transformation technique

Info

Publication number: CN1089409A
Application number: CN 93106472
Authority: CN
Inventors: 刘建平
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-01-07
Filing date: 1993-05-29
Publication date: 1994-07-13
Anticipated expiration: 2013-05-29
Also published as: CN1028138C

Abstract

A kind of six-phase non-feedback inversion transformation technique belongs to the electronic engineering technical field.Major loop of the present invention is made up of chopper, two groups of three-phase independence inverter bridge and Six-Phase Asynchronous Motors.The present invention is characterised in that, the mutual inductance reactor winding by chopper joins with inverter bridge, in 12 thyristors of inverter bridge, always have four or two successively, alternate conduction.The present invention is used for the frequency control of asynchronous motor.

Description

Six-phase non-feedback inversion transformation technique

The invention belongs to the electronic engineering technical field, be specifically related to a kind of six-phase non-feedback inversion transformation technique that is used for variable frequency speed modulation of asynchronous motor.

At present, adopt the AC speed regulating scheme of electronics inversion transformation technique, have higher efficient, wide speed regulating range and level and smooth regulating characteristics have begun in the electric drive field of engineering technology, have obtained using comparatively widely, and have obtained better effects.Chinese patent, H02P7/63, application number are respectively " AC frequency control apparatus and inverter circuit thereof " and " economical RHVC " just wherein representative of genus of 88101020.0,89200379.0.Foregoing invention and utility model all have certain strong point, improving inverter commutation performance, reducing component number and cost, minimizing motor harmonic current and employing can make the reactive current energy feed back to the feedback rectifier of power supply, constituted a kind of new inverse method respectively.Yet, foregoing invention and utility model, all have reactive current energy feedback defective, cause maximum output AC voltage of inverter and transform and its application in electromotor load power to can not get due raising, and, the voltage that the motor winding is born can not become the near sinusoidal ripple, and power factor is lower, does not have fully energy-conservation effect.

Task of the present invention is to seek and a kind ofly can overcomes the defective that prior art exists, and realizes reactive current energy feedback method is not improved voltage quality and effectively energy-conservation.

Concrete technical scheme of the present invention is as follows:

With four triode thyristor T ₇, T ₈, T ₉, T ₁₀, two mutual inductance reactor L with former pair of limit winding ₁₁, L ₁₂, and L ₂₁L ₂₂, two diode D ₃, D ₄With two capacitor C ₂, C ₃Form chopper; By 12 triode thyristor T ₁₁～T ₁₆, T ₂₁～T ₂₆, constitute two groups of three-phase independence inverter bridge.The connecting relation of chopper and inverter bridge as shown in Figure 1, Fig. 1 is an inversion major loop line map.Under the cooperatively interacting of chopper and inverter bridge, form each thyristor conducting (90+ δ) ° inversion process to 30 ° of six phase asynchronous machine changes of current interval average out to.Six-Phase Asynchronous Motors used in the present invention, be to utilize the ordinary three-phase synchronous body, design that the basic principle of design is to guarantee that former circle electromotive force is constant with the hexagon mode of connection, winding pitch becomes full pitch, makes whole winding electromotive force vector be tending towards circular.The concrete course of work of the present invention is like this: as thyristor T ₇, T ₉Conducting, capacitor C ₂Then charging, its polarity are " one " right side " ten ", a left side.At triggering and conducting T ₈, T ₁₀During thyristor, two times of dc voltage values oppositely are added in mutual inductance reactance L ₂₁Former limit winding, and act on the common cathode point of left side inverter bridge, simultaneously, the mutual inductance reactor is paid the limit winding L ₂₂Correspondingly induce two times of voltages, and act on the common anode spot of the right inverter bridge.Again through 60 ° of interval triggering and conducting T ₇, T ₉The time, by mutual inductance reactor L ₁₁And L ₁₂Former pair of winding, reverse shutoff voltage is acted on common anode spot and the right inverter bridge common cathode point of left side inverter bridge, turn-off corresponding thyristor with this reverse voltage.At interval 60 ° successively of the trigger impulses of six phase inverter bridge, conducting (90+ δ) ° matches with chopper shutoff effect, constitutes 12 conducting phase of 30 ° of average out at interval, and in this stage, each thyristor conducting is in proper order: T ₁₁, T ₂₆, T ₁₆, T ₂₁→ T ₁₁, T ₂₁→ T ₁₁, T ₂₂, T ₂₁, T ₁₂→ T ₂₂, T ₁₂→ T ₁₃, T ₂₂, T ₁₂, T ₂₃→ T ₁₃, T ₂₃→ T ₂₄, T ₁₃, T ₂₃, T ₁₄→ T ₂₄, T ₁₄→ T ₁₅, T ₂₄, T ₁₄, T ₂₅→ T ₁₅, T ₂₅→ T ₂₆, T ₁₅, T ₂₅, T ₁₆→ T ₂₆, T ₁₆→ T ₁₁, T ₂₆, T ₁₆, T ₂₁From the thyristor conducting in proper order, clear regularity being arranged, following four, two, four, two phenomenon, that is to say, after four thyristor conductings, is two thyristor conductings; After two thyristor conductings, then another is that four thyristors are in conducting surely.12 thyristors of two groups of inverter bridge have at least two thyristors to be in conducting state, the voltage that makes asynchronous machine can obtain continuing at any time in commutation course.Thereby the thyristor ON time is during greater than 90 °, and the leakage inductance electromotive force of winding forms positive and negative counteracting when the change of current.Make condition that can not open feedback in the motor windings.

At T ₁₁, T ₂₆, T ₁₆, T ₂₁And T ₇, T ₉During conducting, forward voltage is added on the a-c'-b and b'-c-a' two winding branch roads of six phase motor, makes that current values is close on two branch roads.As thyristor T ₁₁, T ₂₁Conducting (30+ δ) °, thyristor T ₂₆, T ₁₆During conducting (90+ δ) °, trigger T ₈, T ₁₀Conducting, thereby T ₇, T ₉Be turned off capacitor C ₁Reverse charging.At this moment, L ₂₁Because of C ₂Two times of direct voltages of last impact then block brachium pontis T under the left inverter bridge ₁₆, L ₂₂Also be bordering on two times voltage, block brachium pontis T on the right inverter bridge because of induction has ₂₆, make T ₁₆And T ₂₆Turn-off at once, asynchronous machine a and a' end are by T ₁₁, T ₁₂Two thyristor single services.At this moment, electric current diminishes between asynchronous machine winding b'-a', and the leakage inductance electric potential direction is pointed to the a' end by b'; At a-b' section winding, to big variation, the leakage inductance electric potential direction is pointed to a end by b' to electric current by little.When selecting suitable angle of flow increment δ for use, above-mentioned two sections winding leakage inductance electromotive forces can be tending towards offsetting.Equally, in a-b section and b-a' section, winding leakage inductance electromotive force also is tending towards positive negative and disappears.Because asynchronous machine a, a' end maintains the voltage effect, the electric current that still has numerical value slightly to reduce along winding two branch roads flows through, makes whole winding induced potential to carry out phase shift continuously.Former pair of winding of two mutual inductance reactance matches with chopper on the one hand, finishes corresponding shutoff effect, on the other hand again because of self character, the electric current that flows through can not suddenlyd change, the change of current is played useful booster action, form inside and outside the condition that makes the not feedback of reactive current energy.

As thyristor T ₂₂, T ₂₁Conducting moment, winding a-c' section electric current changes to little direction, and at this moment, the direction of leakage inductance electromotive force is then pointed to the c' end by a, at c'-b section winding current by little to big variation, then the leakage inductance electromotive force points to the c' end from b.The series relationship of above-mentioned two sections windings still can make positive negative potential be tending towards offsetting.At another winding branch road, the leakage inductance electromotive force in like manner is tending towards offsetting.Phase change takes place in the whole induced potential of winding along with carrying out continuously of handoff procedure, the magnetic field of the magnetic field energy before the commutation course after by the change of current utilizes.Therefore six phase inversion transformation techniques by " four, two, four, two " only alternate conduction is successively arranged in 12 thyristors of inverter bridge, have guaranteed the continued presence and the not feedback of commutation course reactive current energy of induced potential in the motor windings.

The present invention has an embodiment:

Chopper selects for use four to be KP-300A, 1200V thyristor; Two groups of relatively independent three phase inverter bridges are selected 12 KP-200A, 1200V thyristor for use; Silicon cell is selected four 2P-200A, 1200V for use; Select two self-control 0.6mH, 100A reactor for use; C ₁, C ₃Capacitor is selected 800 μ F, 600V electrolytic capacitor for use; Capacitor C ₂Select the capacitance insulation film of 200 μ F, 1200V for use.

Accompanying drawing 2 of the present invention is the groove electromotive force vectogram that 4 utmost points, 36 groove asynchronous machines are changed system into the hexagon wiring.

The present invention has good effect:

1, overcomes the reactive current energy feedback defective that lags behind in the inversion process, realized six phases, 12 pulsation non-feedback inversion transformation processes.

2, improved inversion efficiency, made the maximum output AC voltage of inverter bridge and asynchronous machine bearing power, all made moderate progress.

3, can make that voltage is similar to sine wave on the asynchronous machine winding, when using the dc chopper pressure regulation, the power factor of converter plant can be bordering on 1.0.

4, the present invention can reduce energy consumption, saves energy significantly, has important practical significance.

Claims

1, a kind of six-phase non-feedback inversion transformation technique, its major loop comprise chopper (1), two groups of three-phase independence inverter bridge (2), hexagon mode of connection asynchronous motor, and the present invention is characterised in that chopper (1) is by four triode thyristor T ₇, T ₈, T ₉, T ₁₀, two capacitor C ₂, C ₃With two former pair of limit winding mutual inductance reactor L arranged ₁₁, L ₁₂, L ₂₁, L ₂₂Constitute; Two groups of three-phase independence inverter bridge are by 12 triode thyristor T ₁₁-T ₁₆, T ₂₁-T ₂₆Form; Six-Phase Asynchronous Motors is formed by the common threephase asynchronous transformation of the way.

2, six-phase non-feedback inversion transformation technique as claimed in claim 1 is characterized in that, chopper joins by its former pair of limit winding of mutual inductance reactor and two groups of inverter bridge.

3, six-phase non-feedback inversion transformation technique as claimed in claim 1 is characterized in that, in 12 triode thyristors of inverter bridge, always have four or two successively, alternate conduction.

4, six-phase non-feedback inversion transformation technique as claimed in claim 1 is characterized in that, the Six-Phase Asynchronous Motors winding adopts the hexagon connection.