CN103312241B - Tester in power-down state-the optimizing of a kind of large inertia load permanent magnet synchronous electric heavily throws control method - Google Patents

Abstract

A kind of optimizing making large inertia load permanent magnet synchronous electric tester in power-down state-heavily throw moment impact minimum heavily throws control method.Adopt given rotating speed ω before dropping into ^*suitable input parameter is obtained, in input instantaneously to given rotating speed ω with the mode of position compensation error delta θ real-time update and the mode of voltage inverter simulation ^*with position compensation error delta θ, voltage inverter anode-cathode voltage U _abcwith back electromotive force E _abcpropose certain error limitation; Before preparing to drop into, according to torque balance equation, given rotating speed ω when analyzing minimal impact ^*with the condition that position compensation error delta θ should meet; According to the anode-cathode voltage that real-time rotate speed ω and analog controller simulate with back electromotive force E _abcbetween difference in magnitude phase difference δ, constantly upgrades given rotational speed omega ^*with the difference DELTA ω of actual speed ω ^*with position compensation error delta θ, until start to drop into; Introduce the concept of voltage analog controller, analyze back electromotive force E _abcwith anode-cathode voltage U _abcbetween difference, obtain the region making input moment impact minimum.

Description

Tester in power-down state-the optimizing of a kind of large inertia load permanent magnet synchronous electric heavily throws control method

Technical field

Minimal impact control method is heavily thrown in optimizing when the present invention devises a kind of large inertia load permanent magnet synchronous AC machine drive system phase splitting or short interruptions of powering recovers, belongs to variable frequency ac drive technical field.

Background technology

In AC Drive field, permagnetic synchronous motor has compared with other motors such as induction machine that volume is little, lightweight, the remarkable advantage such as efficiency and output power density is high, detent torque is large, structure is simple, reliable and speed-regulating range width.Along with the research and development of novel permanent magnetic material and the reduction of permanent magnetic material production cost, the research and development technology of permagnetic synchronous motor is just progressively ripe, and it obtains and applies more and more widely in national defence, industrial and agricultural production and daily life etc.Modern permanent magnet synchronous machine has to high-power and trend that is high speed future development.

Along with the fast development of high-speed rail transportation and energy problem, problem of environmental pollution are increasingly serious, the traction electric machine of people to the energy-conservation rail locomotive of new generation of green proposes more and more higher requirement.Permagnetic synchronous motor has become a new research direction as the traction electric machine of locomotive.At present, research in this respect abroad makes some progress, and domestic relevant research is also in the starting stage.

In electric railway, contact line substantially all adopts single-phase segmentation phase changing type to power, at interval of certain distance, motorcycle pantograph all needs to enter an other power supply phase through a neutral section insulator, when passing in and out neutral section insulator, motorcycle pantograph must be electroless state, and now motor driven systems experienced by the process of a power-off-heavily throw; For the system of other permagnetic synchronous motor as power, as the kinematic system of electric automobile and various lathe, if there is restorability fault in short-term, such as have a power failure in short-term and the situation such as protective device startup in short-term, all can occur the process of power-off-heavily throw; Namely permagnetic synchronous motor is in operation and inevitably there is the generation of power-off-heavily throw process.

Also can deposit superincumbent problem for non-magneto, but as permagnetic synchronous motor compared with other motor, the difficult point again dropped into is that its rotor is the permanent magnet of constant excitation megnet, after a loss of power again in input process, excitation field is uncontrollable magnetic field.Between turnoff time, there is higher uncontrollable back electromotive force in three-phase windings; When again dropping into, need the effect considering back electromotive force.For permagnetic synchronous motor, when again dropping into, if ignore the change on the effect of back electromotive force or inappropriate consideration motor internal magnetic field Time and place, very large electric current and torque shock ends will be caused, large impulse current can damage electric machine control system, and large torque shock ends can cause the damage of internal structure of motor and mechanical transmission mechanism.

At present, the domestic transient analysis about permanent magnet synchronous electric tester in power-down state-heavily throw and the technique study how reducing to impact almost do not have, and relevant research mainly concentrates on the four-quadrant how realizing motor and runs without interruption and control and the accurately observation aspect, position of position-sensor-free.How the former aim mainly avoids power-off heavily to throw the appearance of process, makes its motor constantly switch in four-quadrant state as far as possible and realize current of electric uninterrupted operation.Current, the power-off of motor-heavily throw transient analysis mainly to concentrate on induction machine aspect, and the impact existed only is illustrated from emulation aspect that the size of impacting is relevant with the voltage added and phase place, but that specifically analyzes theoretically is few, and do not have not leave for from the angle of amount to determine which concrete influencing factor has and propose how to reduce to greatest extent the method for impact.

Summary of the invention

The technical problem solved

In order to farthest reduce impact during current large inertia load permanent magnet synchronous electric tester in power-down state-heavily throw, proposing and a kind ofly making heavily to throw impulse current and the minimum control method for improving of torque.

Technical scheme

Tester in power-down state-the optimizing of a kind of large inertia load permanent magnet synchronous electric heavily throws control method, it is characterized in that step is as follows:

Step 1: directly cannot measure the anode-cathode voltage of control system after inverter between turnoff time, utilize the voltage analog controller VSC of design, the inverter three-phase simulation reference output voltage u that closed-loop control system current between analog computation turnoff time produces _α ^*, u _b ^*and u _c ^*:

$u_a*=\frac{u_d}{2}[V_1\left(t\right)-V_2\left(t\right)]-\frac{u_d}{6}\underset{i}{\overset{5}{\mathrm{\Σ}}}[V_i\left(t\right)-V_{i+1}\left(t\right)]$

$u_b*=\frac{u_d}{2}[V_3\left(t\right)-V_4\left(t\right)]-\frac{u_d}{6}\underset{i}{\overset{5}{\mathrm{\Σ}}}[V_i\left(t\right)-V_{i+1}\left(t\right)]$

$u_c*=\frac{u_d}{2}[V_5\left(t\right)-V_6\left(t\right)]-\frac{u_d}{6}\underset{i}{\overset{5}{\mathrm{\Σ}}}[V_i\left(t\right)-V_{i+1}\left(t\right)]$

Wherein: i=1,3,5, t >=0, u _dfor inverter direct-flow side busbar voltage, V ₁(t), V ₃(t), V ₅t () is respectively inverter α, brachium pontis IGBT device switch controlling signal on b, c three-phase, V ₂(t), V ₄(t), V ₆t () is respectively inverter α, brachium pontis IGBT device switch controlling signal under b, c three-phase;

Step 2: the permagnetic synchronous motor three phase back-emf e before heavily being thrown by voltage sensor senses _α, e _b, e _c, calculate in optimal-search control device:

Δu _a ^*＝u _α ^*-e _α

Δu _b ^*＝u _b ^*-e _b

Δu _c ^*＝u _c ^*-e _c

Obtain three-phase voltage difference DELTA u _a ^*, Δ u _b ^*with Δ u _c ^*;

Step 3: according to three-phase voltage difference DELTA u _a ^*, Δ u _b ^*with Δ u _c ^*, calculate phase difference by zero passage analytic approach, utilize simultaneously ${U_{\mathrm{\α}}}^{*}=\sqrt{\frac{1}{2\mathrm{\π}}{\∫}_0^{2\mathrm{\π}}{\left({u_{\mathrm{\α}}}^{*}\right)}^2\mathrm{d\ωt}}$ With $E_{\mathrm{\α}}=\sqrt{\frac{1}{2\mathrm{\π}}{\∫}_0^{2\mathrm{\π}}{\left(e_{\mathrm{\α}}\right)}^2\mathrm{d\ωt}}$ Calculating voltage difference in magnitude Δ U _α ^*=U _α ^*-E _α, Δ U _b ^*=U _b ^*-E _bwith Δ U _c ^*=U _c ^*-E _c;

When the error of phase difference exceed ± 1% error range time, change position compensation angle Δ θ ^*for Δ θ=Δ θ ^*± Δ θ ^** 0.01, when the error of voltage amplitude value difference exceed ± 1% error range time, changing speed error value Δ ω is Δ ω ^*=Δ ω ± Δ ω * 0.02;

Until meet error condition;

Step 4: according to ω and Δ ω before heavily throwing ^*calculate given rotating speed ω when dropping into ^*: ω ^*=ω+Δ ω ^*; With position compensation angle Δ θ, real time position is compensated: θ ^*=θ ± Δ θ; According to the torque balance equation of control system, given rotating speed ω ^*be less than real-time rotate speed ω: ω heavily throwing moment ^*=ω-Δ ω ^*, wherein Δ ω ^*>=0;

Step 5: when phase difference and difference in magnitude meet ± 1% error range, optimal-search control device is found to drop into and is impacted minimum point in an electrical cycle: Δ u _a ^*phase place 0, π, or arbitrfary point, above approaching, the error angle of arbitrfary point exists scope within time, send drop into order, given speed no longer according to real-time rotate speed upgrade, the control of the controlled device of the controllable devices in inverter, makes the electric control system of permagnetic synchronous motor again put into operation.

Beneficial effect

This method has the following advantages: according to the Optimal Input point calculated, and greatly reduces the impulse current and impact torque of heavily throwing moment.What native system realized is that the minimal impact of a closed-loop system heavily throws process, and the transient process avoided after heavily throwing from open loop to closed loop is impacted.

Accompanying drawing explanation

Fig. 1: be general structure block diagram of the present invention;

Fig. 2: be the three-phase voltage difference curve between three-phase simulation reference output voltage and three phase back-emf;

Fig. 3: be control system operational flow diagram of the present invention.

Embodiment

Now in conjunction with the embodiments, the present invention is described further for accompanying drawing:

Technical scheme of the present invention is: when the driving AC shutdown transient with large inertia load permagnetic synchronous motor being detected, disconnects control end K switch A.When above-mentioned AC service restoration being detected, according to the given rotational speed omega being slightly less than this value of current real-time rotate speed ω ^*voltage analog controller is utilized to calculate the three-phase simulation reference output voltage value of current closed-loop control system inverter, use voltage sensor senses three phase back-emf now, result is between the two compared in optimal-search control device, if difference is between the two in certain scope, by optimal-search control device, the heavy cultellation calculating and find minimal impact is heavily thrown; If difference is not between the two in certain error range, correct given rotating speed error delta ω ^*with compensated position angle Δ θ, until meet input condition.

Step of the present invention:

Step 1: directly cannot measure the anode-cathode voltage of control system after inverter between turnoff time, utilize the voltage analog controller VSC of design, the inverter three-phase simulation reference output voltage u that closed-loop control system current between analog computation turnoff time produces _α ^*, u _b ^*and u _c ^*.Namely $u_a*=\frac{u_d}{2}[V_1\left(t\right)-V_2\left(t\right)]-\frac{u_d}{6}\underset{i}{\overset{5}{\mathrm{\Σ}}}[V_i\left(t\right)-V_{i+1}\left(t\right)],$ $u_b*=\frac{u_d}{2}[V_3\left(t\right)-V_4\left(t\right)]-\frac{u_d}{6}\underset{i}{\overset{5}{\mathrm{\Σ}}}[V_i\left(t\right)-V_{i+1}\left(t\right)],$ $u_c*=\frac{u_d}{2}[V_5\left(t\right)-V_6\left(t\right)]-\frac{u_d}{6}\underset{i}{\overset{5}{\mathrm{\Σ}}}[V_i\left(t\right)-V_{i+1}\left(t\right)]$ Wherein, i=1,3,5, t >=0, u _dfor inverter direct-flow side busbar voltage, V ₁(t), V ₃(t), V ₅t () is respectively inverter α, brachium pontis IGBT device switch controlling signal on b, c three-phase.V ₂(t), V ₄(t), V ₆t () is respectively inverter α, brachium pontis IGBT device switch controlling signal under b, c three-phase.

Step 2: the permagnetic synchronous motor three phase back-emf e before heavily being thrown by voltage sensor senses _α, e _b, e _c, by Δ u in the optimal-search control device of design _a ^*=u _α ^*-e _α, Δ u _b ^*=u _b ^*-e _bwith Δ u _c ^*=u _c ^*-e _cobtain three-phase voltage difference DELTA u _a ^*, Δ u _b ^*with Δ u _c ^*.

Step 3: optimal-search control device is according to three-phase voltage difference DELTA u _a ^*, Δ u _b ^*with Δ u _c ^*, calculate phase difference by zero passage analytic approach, utilize ${U_{\mathrm{\α}}}^{*}=\sqrt{\frac{1}{2\mathrm{\π}}{\∫}_0^{2\mathrm{\π}}{\left({u_{\mathrm{\α}}}^{*}\right)}^2\mathrm{d\ωt}}$ With $E_{\mathrm{\α}}=\sqrt{\frac{1}{2\mathrm{\π}}{\∫}_0^{2\mathrm{\π}}{\left(e_{\mathrm{\α}}\right)}^2\mathrm{d\ωt}}$ The voltage effective value calculating voltage difference in magnitude Δ U calculated _α ^*=U _α ^*-E _α, Δ U _b ^*=U _b ^*-E _bwith Δ U _c ^*=U _c ^*-E _c.Whether the error of both judgements all meets ± 1% error range.When phase difference does not meet, by correction position offset angle Δ θ, make new Δ θ=Δ θ ± Δ θ * 0.01; When difference in magnitude does not meet, by correcting speed error value Δ ω ^*, make new Δ ω ^*=Δ ω ^*± Δ ω ^** 0.02; Mode is above utilized constantly to correct, until meet error condition.

Step 4: according to ω and Δ ω before heavily throwing ^*calculate given rotating speed ω when dropping into ^*, i.e. ω ^*=ω+Δ ω ^*; Position compensation angle Δ θ obtained above is utilized to compensate real time position, i.e. θ ^*=θ ± Δ θ.According to the torque balance equation of control system, in order to when making heavily to throw need balancing moment try one's best little, given rotating speed ω ^*the real-time rotate speed ω heavily throwing moment should be slightly less than.I.e. ω ^*=ω-Δ ω ^*, wherein Δ ω ^*>=0.

Step 5: when the phase difference judged in step 3 and difference in magnitude all meet ± 1% error range time, the minimum point of input impact found by optimal-search control device in an electrical cycle, i.e. Δ u _a ^*phase place 0, π, or arbitrfary point, above approaching, the error angle of arbitrfary point exists scope within time, send and drop into order, given speed no longer upgrades according to real-time rotate speed, and the controllable devices in inverter starts the control of controller by the present invention's design.Thus the electric control system of permagnetic synchronous motor is put into operation again.

Primary structure of the present invention is as follows:

1. rotational speed setup module: the correction error rotating speed Δ ω calculated according to the instantaneous real-time rotate speed ω before input and optimal-search control device ^*obtain the given speed ω dropping into moment ^*.

2. voltage analog controller VSC: analog computation inverter output voltage.

3. optimal-search control device: correct given rotating speed error delta ω ^*with position compensation angle Δ θ, select the best input moment.

4. buffer capacitor C: power-cut time cushioning effect.

5. inverter control K switch A: the controlled power switch such as relay, contactor.

6. three-phase full-bridge inverter

7. three-phase permanent magnet synchronous motor

Objective for implementation of the present invention is three-phase permanent magnet synchronous motor, and this motor application is in the large inertia loads such as electric traction, electric automobile, screw.

Embodiment: power-off-optimizing heavily throws system block diagram as shown in Figure 1, comprising given module, VSC voltage analog controller, optimal-search control device, pi controller, the conversion module of CVCM electric current to voltage, the assembly such as control module, buffer capacitor C, three-phase full-bridge inverting circuit, testing circuit of voltage dq-abc conversion of rotating speed.Its operation principle is: when large inertia load permagnetic synchronous motor runs with constant speed ω, detect that Alternating Current Power Supply side power supply disconnects, and the busbar voltage of motor due to the existence of electric capacity can not at once power-off, close the controllable devices of all inverters, make it all be in closed condition; After detecting that AC has electricity, detect the actual speed ω of motor at that time, actual speed ω is deducted less margin of error Δ ω ^*as given rotating speed ω ^*, Negotiation speed closed-loop system obtains certain control voltage signal u _abc, utilize analog controller to calculate corresponding control voltage signal u _abcinverter three-phase simulation reference output voltage that should be corresponding will with the back electromotive force E detected _abcamplitude and phase place contrast, obtains difference in magnitude and phase difference; Judge its difference whether within certain error range, if met, obtain new given rotating speed ω according to such control mode ^*, when the phase place of back electromotive force arrives π and position heavily throw, in one-period, have six such numerical points; If do not met, by optimal-search control device, given rotating speed error amount Δ ω and feedback position offset angle Δ θ is adjusted, thus rejudge according to process above.

The present invention introduces its execution mode for railway permagnetic synchronous motor, is specifically divided into following step:

1. when detecting that AC has voltage to occur, according to current actual speed ω, certain error tachometer value Δ ω is in a small amount deducted ^*after the value that obtains as given rotating speed.The measurement of real-time rotate speed can derive from encoder, resolver or calculate according to back electromotive force.

2. according to three-phase voltage control signal u _abcthe three-phase simulation reference output voltage substantially identical with being truly loaded into motor end is obtained in voltage analog controller

3. to the real-time back-emf value E detected _abcwith three-phase simulation reference output voltage amplitude and phase difference carry out certain judgement.

If two kinds of error magnitude errors 4. between the two with phase error δ ^*do not meet certain error tolerance, to given rotating speed ω ^*correct with the error delta ω of actual speed ω and the position compensation angle Δ θ of feedback position θ.The balancing moment T making it drop into need instantaneously _ewith q shaft current i _qlittle, thus the inverter anode-cathode voltage U reducing input as far as possible _abcwith back electromotive force E _abcbetween amplitude and phase difference.

If two kinds of error magnitude errors 5. between the two with phase error δ ^*all meet certain error tolerance, detect the back electromotive force E in nearest cycle _abcbest switching point, close to after send heavy voted signal op and KA-M and make given rotating speed no longer change according to actual speed, relay K A is worked, the controllable devices starting to control power inverter according to control signal works accordingly.

Finally, after dropping into successfully, current closed-loop is added in the controls.

Claims (1)

1. tester in power-down state-the optimizing of large inertia load permanent magnet synchronous electric heavily throws a control method, it is characterized in that step is as follows:

Step 1: directly cannot measure the anode-cathode voltage of control system after inverter between turnoff time, utilize the voltage analog controller VSC of design, the inverter three-phase simulation reference output voltage u that closed-loop control system current between analog computation turnoff time produces _α ^*, u _b ^*and u _c ^*:

$u_a*=\frac{u_d}{2}[V_1\left(t\right)-V_2\left(t\right)]-\frac{u_d}{6}\underset{i}{\overset{5}{\mathrm{\Σ}}}[V_i\left(t\right)-V_{i+1}\left(t\right)]$

$u_b*=\frac{u_d}{2}[V_3\left(t\right)-V_4\left(t\right)]-\frac{u_d}{6}\underset{i}{\overset{5}{\mathrm{\Σ}}}[V_i\left(t\right)-V_{i+1}\left(t\right)]$

$u_c*=\frac{u_d}{2}[V_5\left(t\right)-V_6\left(t\right)]-\frac{u_d}{6}\underset{i}{\overset{5}{\mathrm{\Σ}}}[V_i\left(t\right)-V_{i+1}\left(t\right)]$

Wherein: i=1,3,5, t >=0, u _dfor inverter direct-flow side busbar voltage, V ₁(t), V ₃(t), V ₅t () is respectively inverter α, brachium pontis IGBT device switch controlling signal on b, c three-phase, V ₂(t), V ₄(t), V ₆t () is respectively inverter α, brachium pontis IGBT device switch controlling signal under b, c three-phase;

Step 2: the permagnetic synchronous motor three phase back-emf e before heavily being thrown by voltage sensor senses _α, e _b, e _c, calculate in optimal-search control device:

Δu _a ^*＝u _α ^*-e _α

Δu _b ^*＝u _b ^*-e _b

Δu _c ^*＝u _c ^*-e _c

Obtain three-phase voltage difference DELTA u _a ^*, Δ u _b ^*with Δ u _c ^*;

Step 3: according to three-phase voltage difference DELTA u _a ^*, Δ u _b ^*with Δ u _c ^*, calculate phase difference by zero passage analytic approach, utilize simultaneously ${U_{\mathrm{\α}}}^{*}=\sqrt{\frac{1}{2\mathrm{\π}}{\∫}_0^{2\mathrm{\π}}{\left({u_{\mathrm{\α}}}^{*}\right)}^2\mathrm{d\ωt}}$ With $E_{\mathrm{\α}}=\sqrt{\frac{1}{2\mathrm{\π}}{\∫}_0^{2\mathrm{\π}}{\left(e_{\mathrm{\α}}\right)}^2\mathrm{d\ωt}}$ Calculating voltage difference in magnitude Δ U _α ^*=U _α ^*-E _α, Δ U _b ^*=U _b ^*-E _bwith Δ U _c ^*=U _c ^*-E _c;

When the error of phase difference exceed ± 1% error range time, change position compensation angle Δ θ ^*for Δ θ=Δ θ ^*± Δ θ ^** 0.01, when the error of voltage amplitude value difference exceed ± 1% error range time, changing speed error value Δ ω is Δ ω ^*=Δ ω ± Δ ω * 0.02;

Until meet error condition;

Step 4: according to ω and Δ ω before heavily throwing ^*calculate given rotating speed ω when dropping into ^*: ω ^*=ω+Δ ω ^*; With position compensation angle Δ θ, real time position is compensated: θ ^*=θ ± Δ θ; According to the torque balance equation of control system, given rotating speed ω ^*be less than real-time rotate speed ω: ω heavily throwing moment ^*=ω-Δ ω ^*, wherein Δ ω ^*>=0;

Step 5: when phase difference and difference in magnitude meet ± 1% error range, optimal-search control device is found to drop into and is impacted minimum point in an electrical cycle: Δ u _a ^*phase place 0, π, or arbitrfary point, above approaching, the error angle of arbitrfary point exists scope within time, send drop into order, given speed no longer according to real-time rotate speed upgrade, the control of the controlled device of the controllable devices in inverter, makes the electric control system of permagnetic synchronous motor again put into operation.