SU1647840A1 - Staged electric drive - Google Patents

Description

FIG. one

The invention relates to electrical engineering, in particular to an automated electric drive, and can be used in asynchronous cascades with a controlled rotary valve group (rotary frequency converter with an intermediate DC circuit), for example, for shaft fans, pumps for drainage plants.

The aim of the invention is to reduce electric power losses when an asynchronous motor with a phase-rotor is undercharged by indirectly controlling its reactive power.

Figure 1 shows the functional diagram of the cascade electric drive; Fig. 2 shows a replacement circuit for an asynchronous motor with a phase-rotor; Fig. 3 shows the curve of the dependence of the average rectified current id on the angle "and control of the EMF-rotor converter, corresponding to the nominal heat loss in an asynchronous motor with a phase rotor.

The cascade electric drive contains an asynchronous electric motor 1 (Fig. 1), the phase rotor of which is connected to the terminals of the alternating current of the converter 2 of the EMF-rotor, made in the form of a controlled DC valve converter which is connected to the DC buses of the source 3 additional EMF, made in the form of a controlled DC converter. The rectified current circuit includes a current sensor 4, the output of which is connected to the first input of the first adder 5 having four inputs, the second, third and fourth inputs being connected respectively to the outputs of the nonlinearity unit 6, the main parameter controller 7 and the limit unit 8. The output of the adder 5 is connected to the input of the regulator 9 of the average rectified current, the output of which is connected to the control input of the source 3 of the additional EMF. The circuit includes the sensor 10 of the main control parameter, the output of which is connected to the input of the second adder 11, the second input of which is connected to the setpoint controller 12 of the main control parameter, and the output through the regulator 7 of the main control parameter and the restriction unit 8 to the control input of the EMF converter 2 rotor Elements 4, 5 and 9 form a current loop 13 closed to the source of the additional emf, and elements 7, 10 and 11 form the main control parameter loop 14 closed to the EMF-rotor converter.

Figure 2 shows the active resistance of the 15 stator phase of the asynchronous electric motor 1 (p), the inductive resistance of the 16 stator phase of the asynchronous

electric motor 1 (xt), active resistance 17 of the rotor phase of the asynchronous electric motor 1, reduced to the stator (yy}, inductive resistance 18 of the rotor phase of the asynchronous electric motor 1, connected to the stator (х2), active resistance 19 of the magnetizing branch of the asynchronous electric motor 1 (rm) , inductive resistance 20 of the magnetization branch of the induction motor 1 (xm),

5 resistance is equivalent to 21 mechanical power of asynchronous electric motor 1 ()

The device for automatic control of the cascade electric drive works as follows.

To adjust the main control parameter (for example, the angular velocity of the asynchronous motor 1), a driver signal is generated in the controller 12, which is compared in the adder 11 with the main feedback signal from the main control parameter sensor 10, the resulting difference

0, the control signal is fed to the input of the regulator 7 of the main control parameter, and from it through the limiting unit 8 to the control input of the EMF-rotor converter 2. Thus, at the control input

5, converter 2 generates a signal proportional to its control angle or some function of that angle (for example, cosine). In addition, this signal is fed to the input of nonlinearity unit 6, which forms a reference for controlling the average rectified current. The output of the nonlinearity unit 6 is fed to the second input of the adder 5, to the first input of which a signal is supplied from the current sensor 4.

5 The output signal of the adder 5 is fed to the input of the regulator 9, which generates a control signal for the source 3 of the additional emf.

0 An increase in the load on the shaft of the asynchronous electric motor 1 (if the load decreases, the process goes in the opposite direction) leads to a decrease in the control angle of the EMF-rotor converter 2, and therefore to an increase in the torque of the motor 1, which is proportional to the product of the rectified current Id and the cosine of the angle control transducer 2,

A change in the control angle ag will entail some change in the task / ur control of the current Id. This is necessary for the CLR to use as fully as possible; asynchronous electric motor i at Tt plut and is due to the fact that the total heat loss in the asynchronous motor, oe - hangs from the average rectifier tokz, and from the angle of control the elg 2 of the rotor is transformed. There is an unambiguous non-linear effect. The specified current depends on the angle of the evo- lution of the converter of the 2 emf-rotor at which the total heat from the coil in dz.a.ele 1 equal nominal It is precisely on dependence and modeling that is block 6

Analyze c-sci this dependency is to use goluchens on the basis of the replacement scheme e - and asynchronous gv / atel

Aid for next p / 112 2

p2 rm - {.2 2

 "} {2}

i p

1 (fi-7) g, p equation

Vi /, i

I- - ii - 2,

. n + where {) is the tog of the othera,

12 - given to the stator

fm -tg magnetization; D P J - total thermal goat-pvi in the asynchronous motor;

2g, P - T; + j (X 4 Xmj, Z12 - - (rm JXiJ

Bring the Egna K Bi an erik current at a z on the first t phono is associated with an IM corrected current by the following relation

(what

., y2. |, .e-b2

(four)

To s

O.2- yrofi control of airframe 2 EMF-island,

K - coupling of the transformation of the EMF of an induction motor 11

2 - the phase of the TC given to the stator, and the rotor (for the tf2 under consideration - –12}

If you take to ensure that the losses of AP2 are equal to nominal, then equations (1) - (4) form (system of equations, analogue-: km expressing the desired dependence. Such dependence, calculated, for example, MTM 613-10 prl any theoretically smoke control corners of the 2 emf-poropa converter, shown

i f FI.Z.

When, since nonlinearity unit 6 is to simulate this zlissimos-o, a signal proportional to the control angle of the transducer is applied to its input.

UWHB KlCQ,

and the output signal after non-linear conversion is proportional to the average rectified current

Ijbt hb kg iq

where Ki, K2 coefficient, g.opogosh p alnosti

Pr, the operation of the drive NOT i -.ry arise neperp 3Ki pr which has a static memory) more than the time of the asynchronous movement of the Pope. The converter-1 converter of the ZDS-rotor is equal to zero, so this will not be enough for what you want “rrsg0-o It is controlled from the OEC of Chaye Sun. This means that it is valid e -.pe j oJ-d PTK medium & mtr, CHHL gc - On -crrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr. r i.c v-ic: i yu gt / Ps - i, oks1 ssgm. shred te (CH 20 chul / lm. 3t) u / ij;

.

the regulator and a о d i tcr is a common bi TssofVl rriv, then h. iv treobrazo

u b,) C1 o f a

(sp

AT 5

her - About the decree. NOp3C

25 rcovn) It is pr / vl - s tokg 1a m BOSO and jule, according to. About j, i g ophthalmic igt isioa later,.

Thus i5r.33Cii npi, at 30ijp Haroycj, f 0u bj v J. a Cc.30 t / psgtochnogo -ok r-gaaae zze cf., match.Y | 1, and i hrls-i to r - Gm lost m from the asynchronous dvlelee eregulated- L1 oovap ie t, gz pa, 0Ј yg: a prefielder4ch is due to -is enene s vi lz prevented 35 lay 1 transistor 2 EMF of the rotor With mntno Po1 "ps isozg. rpc Spc OBSTc-, r.Lii pet pa transform 2t l with specialty, oleaning (for example ry.pol.polchechiv by nc .fostuyu controlled by t: m and x) asynchronous stator - wigatelg f 1pause the nausea of the emptiness of theo 0 5yiK comp. Nsvaz; 45 peaKTiisf ld qyag, second character, associated with the ng-v egyan ti, the transducer of the lagging control, un - used as a quality source 3

50 additional SLM a and ii call the consumption of a drive with; mi-aon reactive power.

Claims (1)

Claims of the invention of the Cascade electrical transducer with constants55 of an electrical motor with fzЈ, -. (A switch, connected to the terminals of the transfer current of the EMF-rotor converter, the source of the additional EMF, 1 are made in the form of a controlled vein ( DC current and connected via a current sensor to the DC buses of the EMF-rotor converter, the average rectified current controller connected by the output to the control input of the secondary EMF source, and the input to the output of the pendulous adder connected by the first input to the output the current sensor, the sensor and the setpoint of the main control parameter connected by the outputs to the inputs of the second adder, the output of which is connected to the input of the regulator of the main control parameter, characterized in that, in order to reduce energy losses at short time Asynchronous motor with a phase rotor by indirect control of its reactive power, a limiting unit and a nonlinearity unit are introduced, realizing five The dependence of the average rectified current on the control angle of the EMF-rotor converter, corresponding to the nominal heat loss in an induction motor with a phase-rotor, and the EMF-rotor converter is made in the form of a controlled DC converter and is equipped with a control input combined with the input of the named nonlinearity unit, the second input of the first adder and connected to the output of the limiting unit, the input of which is combined with the first additional input of the first adder and connected to the output of the main control parameter controller, while the output of the nonlinearity unit is connected to the second auxiliary input of the first adder. Yu Fi2,2 -160 -PO -80 -W W DO PO SO W