SU699617A1 - Power-diode electric motor - Google Patents

Description

(54) VENTILATION ELECTRIC MOTOR

The invention relates to the field of electrical engineering and can be used to create a motor with zero-clock commutation. A valve motor containing measles is known to be connected obkutyko to the output of the inverter and an inductor with an excitation winding connected to the inverter's DC circuit and connected via a cutting diode to an additional power source 1. A disadvantage of the known electric motor is the complexity of its operation. The closest in technical essence to the proposed invention is a valve POWER, containing measles with a multisection winding connected to the output of an inverter with natural commutation and clock synchronization of the core voltage and having an inductor with an excitation winding and an additional power source excitation circuit 2. The disadvantage of the known engine is not enough high overload capacity and stability, especially in dynamic modes, Goal and Regained - improving surge capacity and stability of the engine -. The goal is achieved by the fact that the excitation winding and its power supply are interconnected in series and connected in parallel to the choke, and the power supply is equipped with a regulator covered by a rigid non-linear positive feedback on the current consumption, capri 1p, current cut-off. The invention is illustrated by the drawings, where FIG. 1 is a schematic diagram of a valve motor Q with an excitation controller, FIG. 2 shows in relative terms the current-voltage characteristics of the excitation controller and current distribution in a valve engine; FIG. 3 shows structural diagram of the valve motor with the proposed excitation controller, and in FIG. 4 — the characteristics of the engine; The electric switch contains a three-phase synchronous motor (SD) 1, a current inverter on controlled semiconductor valves ( iristorah) i, controllable rectifier 3, a pulse phase control system (IFSB) .invertorom 4, audio CD excitation winding 5; source independent of excitation. 6 f the control unit of this source 7, smoothing choke 8 node of non-linear positive feedback., On load current - cut-off 9, SIFU rectifier 10. The drawings give the following conventions: I. - graph of excitation current, necessary (required) to provide a constant magnitude of the magnetic flux into the gap ("p const), 12 is a graph of the excitation current as a function of the load current in the current cut-off interval, 13 is a graph of the change in the positive current feedback signal with a cut-off ( ), 14- schedule The change in the cyi / SMapHoro control signal at the input of the independent excitation source, Lu 15, shows the graph of the variation of the excitation current as a function of rigid continuous positive feedback on the load current UBX g in%. n. lh control inputs, respectively, of a rectifier, an inverter, an independent, excitation source. ;. A continuous positive positive feedback current feedback signal. - the same external feedback with cut-off. The constant voltage source 6. (Fig. 1) together with the control unit 7, -Winding, excitation 5 synchronous motor 1, smoothing throttle 8 and cut-off node 9 constitute the excitation regulator. It is loaded through the excitation winding 5 of the engine 1 to the throttle 8, In the idling mode of the valves; The synchronous machine 1's excitation motor is provided with an independent power source of the excitation control, and its electric angle the rotor frequency (rotor speed) is determined by the ratio: first harmonic of the motor's phased voltage, inductance of mutual inductance along the longitudinal. the axes of the synchronous machine, brought to the stator winding, the excitation current when the LED is idling. .In static loading of a motor, its speed is determined based on the characteristic described by the expression: fmt coiM, - mi. A: g (4 (+ C) -3, .2 (4, -0) GP1, H is the first harmonic of the output current of the inverter and the shear angle between this current and., The stator voltage CM, U, L, .- - total inductance of the synchronous machine along axis m d and t, - active resistance of the phase of the winding box, synchronous motor, I T | - reduced excitation current to the winding, synchronous motor, 0 - load angle of the SD, from which it follows that the slope (rigidity) of the speed (mechanical) characteristics of the system at any point depends on the ratios me5 (bdu @ C- | j -jV and F; at an unregulated excitation current (3 const) and s the control parameter tse with an increase in the resistance impedance on the shaft gradually, the load angle 9 increases the engine speed, thus giving the speed mechanical characteristic positive rigidity, making it impossible for the engine to work steadily under load. Statism requires a change., the motor winding current, and hence the current of the independent power source as a function of the load current for a certain,., based on the requirements of p The generalized analytical law for the regulation of the excitation current as a function of load and speed for a given control parameter (n) const) is obtained from the above equation for the speed characteristic tick and: U, coscp, + (- t) smfq), + 6) smQf smtfj i-ad E ° (W-D sinCq), + © Link this current to the load current to obtain, for example, stable static mechanical characteristics of the final (negative) one. stiffness is detected through the magnetic flux in the air gap of the synchronous motor, which must remain constant tf -const

and the current in the excitation winding should vary according to characteristic 11, fig.

Current distribution in the excitation regulator of the valve engine under the condition of maintaining constant

magnetic flux (c.onat) is determined by the replacement scheme:

- .41-

to

dr r-M-ri-t g

- + U

dfl sp

5p

Eg is the emf of an independent power source of the excitation winding at idling 5 during a valve motor. dfl input (smooth component). current, inverter, t mt tjC g - coefficient taking into account the switching process 9 () 2fo) f, l, e1ive resistance, respectively, of the excitation winding, smoothing throttle and internal resistance of the independent power source. It indicates that with E -ronsi .. the current of the excitation winding itself will not change according to the proportional law (according to characteristic 15, Fig. 2) due to the internally positive rigid feedback due to the input current of the inverter realized by the proposed excitation regulator . The coefficient of this feedback K ,: S e depends on the ratios of the resistances of the elements of the excitation controller and, 8 in the general case, can be adjustable. To form the law of regulation f - (,) or Е - | (Jni) i characteristics 11 of FIG. 2, an independent power source (which can be controlled controlled rectifiers, electric machines or magnetic amplifiers with a DC output) is covered by external positive, hard, non-linear feedback, for example, load current with cut-off. The operation of this node (9), and, in general, the excitation controller is illustrated in FIG. where the cutoff signal is depicted by characteristic 13, and the total input

signal of independent source ntlTan - 14,

Excitation current is now determined by expression;

+ 3

f, + r, -i-ti

 d

where H is the emf of independent control of the power source.

E (C

in .. In,

ten

the gain of the independent excitation source over voltage, the input signal of the excitation channel, determined by the idling conditions of the valve engine. ".. Chzst - current cutoff signal,, (,) Kj - gain factor, current cutoff signal, Ka. tgc (cM.x-Ky 11 of Fig. 2),, 6 cut-off current. Consequently, the resulting excitation current function 3f - V i dp + 2 d | 5 / dft d / Jo ,, allows approximation fairly accurately. modify the desired - characteristic (11) ff (-mi) (see Fig.2) by two piecewise linear sections, one of which (15) in the load current range from zero to the cut-off current is due to internal positive feedback and the other (12 - from the cut-off current; ki to its maximum value - external positive rigid feedback on the load current with the cut-off. The parameters K and K are determined when the desired characteristic (11) is approximated by two segments (12) and (15) ). By the magnitude of the maximum required current of the excitation winding (f.) And by the maximum To the voltage of the source of independent excitation 11, the power of this source is determined by adjusting Fz-const: TJ, UBH3fH-V i- d / 5o,; "2Xa" J e "J 2 dft J4Drtl - ,, UBv-b (o) J IT is the power source voltage selected according to the idling conditions of the valve engine. Due to the demagnetizing nature of the longitudinal root reaction from the load current and the absence of a rotor position sensor, the valve engine is similar to an uncompensated DC collector machine with a loosely fixed brush mechanism very sensitive outrage any channel, exhibited by the current through the load. Moreover, at small angles of advance unlocking - the gates In the inverter providing the best use of the synchronous machine / 3, f 4-5, the limit of the dynamic stability of the sietem is generally limited to the inverter. for small coscpi, this limit is limited by the allowable motor current. Analysis of engine transfer function over this current t /, / j (P) i CP) (: P wfP) where W (P) is the characteristic 4th order valve motor polynomial, W, (P), WjCP) are the corresponding 3rd order polynomials on the control actions from the input circuit of the investor cig, and excitation LEDs Uf shows that in the absence of regulation on the input channel of the inverter or on the excitation channel of the synchronous machine, the valve engine is unstable, since some coefficients characteristic equations are negative. Relatively simply stable jobs i. The stabilization of the velocity of the VD at any voltage maturity is ensured by acting on the excitation channel with the help of this excitation regulator. This follows from the equation given to the electric equilibrium stator through the excitation channel in the circuit of this regulator without current cutoff. . Tde. - full, brought to the stator, flux linkage of the excitation winding of the synchronous motor (h,) or i / p).) "SRPd P f; a ,, 5Gf, + C) c, 2 Lp - Le + c; , k .d W + nj + r p-, bo + n, + geh „-. b Lao / Kd tKd damper winding diabetes on the longitudinal axis and its inductance. An analysis of this equation shows the presence in the excitation channel of an internal positive feedback on the load current and its derivative simultaneously, i.e. . o, P-fb, Uroc S TbT acting in the direction of the compensation, no demagnetizing component of the load. At. 1, bo, (o) .- g-4, g-a,. ° L p t g (G) () t where t d Uy K a,. Kg - coefficient of independent source voltage. Now, the transfer function of the VD with regulation using a controller without current cut-off is expressed by the equation:,. ) W, (P) + UyCP)) WgCP)), o, P + b, where w (P) WfP) -: 5rpTb. which corresponds to the structural scheme of figure 2. Analysis W (P) shows the fulfillment of the conditions for the stability of the VD. When regulating with cp - const in the whole range of loads in the operator expression (), the term takes into account the action of the cutoff channel, and the transfer function of the system will be: j / p)) w, (P) iU .b (, ni.i TYPJ where W (P} W2 (: P) -Wp (-P) / (P), / P), which corresponds to the complete block diagram of the valve motor with this controller, is shown in Fig. 2. Thus, the electric motor can be used for mechanisms both with a smoothly changing load (pumps, fans) and a variable or sharply variable

load (blowers, piston compressors, etc.).

Claims (2)

1. US patent number 2133919, CL 318138, .1940. 2.Arakel A.K. and others. The valve electric drive with a synchronous motor and a three-way inverter. M., Energie, 1977, p.144. R , ch (