SU490247A1 - Adjustable electric drive with asynchronized synchronous motor - Google Patents

Description

The system of rotational speed control, iie inferior to the quality of regulation of the driving current drives.

2. The drive must have overload capacity, limited only by the power of the power supply, and not by the dynamic properties of the engine.

3. The drive must have an automatic reactive power control system to value the stator in order to maintain it at an economically viable level.

The purpose of the invention is to expand the range of speed control and adjustable mobility and increase the quality of speed control over time.

A feature of the proposed electric drive is as follows.

The control system is not built in phase coordinates, as is usually done, but in synchronously rotating coordinates a, p, for which blocks of direct and inverse transforms of variable are introduced into the system. In coordinates a, (3 at steady state, all values characterizing engine operation are constant. Consequently, regular adjustments built at the specified coordinates at steady conditions exclude the occurrence of phase errors, i.e. filters in the control system do not affect the steady state mode.

To affect the stator current, its components are adjusted according to the axis, for which current-axis regulators are introduced into the system. This makes it possible to separately (independently) act on the electromotive motor torque (through the current regulator / d), and its reactive power (via current regulator / s).

Impact on the torque and reactive power of the engine can also be carried out through the components of the rotor current values (current regulators iy ,, and 13 / -) - This makes it possible to build several options for controlling the ASD, for example: by stator current, on rotor current, combined options.

In order to create a drive with an ASD of the properties of a DC drive with variable speed, a speed regulator with an intensity indicator was introduced into the system. This provides, firstly, the ability to automatically maintain the speed of the ASD at the target level regardless of the load on the shaft, and secondly, it enables the drive to be included in the automatic control system of the speed control system.

To impart the properties of a synchronous compensator controlled by reactive power to an electric drive with an ASD, a p-meter current meter was inserted into the system, i.e., the stator reactive current settings. This provides with the help of a current regulator on the p axis, in the nerves, the possibility of automatically maintaining the reactive power of the stator of the ASD on

the reference level regardless of the load on the shaft and the rotational speed, and secondly, it makes it possible to turn on the electric drive in the automatic control system of the reactive

power ASD.

The regulation system provides for compensation of the harmful effects of e. d. slip on the dynamics of the electric drive, for which the flowmeter of the blind rotor is introduced

but os. mc, p, slip meter and multiplier elements with dynamic links.

The regulation system is built according to the pressure gauge; Tsipu systems of subordinated regulation with

consistent correction so that the current controllers and the speed controller compensate for the main electromechanical and electromagnetic inertia of the ASD. This makes it possible to execute an electrical drive with high speed and ensure its high overload capacity, the value of which is limited by the power sources of the stator and rotor circuits, and not by the dynamic properties of the ASD.

Since the control system for the ASD is built on the use of slowly varying quantities (components on the axis, p), it can be 1) 1 real-life ociroBe of the UBSR elements developed by the electric drive of the electric current.

Pa figs. Figure 1 shows the functional scheme of the proposed electric drive with an ASD controlled by the stator currents on a rotor current (option I); in fig. 2 is a diagram of a simplified version of regulation by stator currents (variant I).

The scheme contains an asynchronous synchronous motor (ASD) 1, static reversible adjustable power supply sources of 2 phases

rotor of ASD, sensor of angular position 3 of rotor of ASD, speed sensor of ASD (tachogenerator) 4, block for direct conversion of 5 stator currents from phase values to synchronously rotating coordinates a, p, block n.

converting 6 rotor currents from phase ve. 1НЧНН to synchronously rotating coordinates, block of inverse conversion 7 from synchronously rotating coordinates to phase coordinates, measuring the difference of speeds: synchro-synchronous and

rotor (slip meter) 8, flux meter 9 of the rotor winding in axis a, meter of flux drift 10 of the rotor winding in axis p, stator current regulator 11 along a axis, stator current regulator 12 along p axis, task 13 current transducer along p axis (the source of the task is on the reactive power of the stator of the ASD), the integral elements are 14, the dynamic links 15 in the chains of positive links along e. d. rotation, speed controller (source of reference but the torque of the ASD) 16, filters 17 in the speed reference circuit, setpoint signal 18, speed reference, source 19 of the speed reference signal.

The stator winding of the ASD 1 is powered by a source of symmetric three-phase spontaneous voltage with a constant angular frequency of coj. Each phase of the rotor The ASD is powered by one of the reversible regulated power sources 2. The power sources of the rotor phases have a linear relationship between the input control voltage and the rectified voltage. On the ASD shaft, there is an angular position sensor 3 for the rotor with respect to synchronously rotating axes a, P whose output signals are proportional to the trigonometric functions of the angular position of the rotor for the ASD and cos y (where Y; is the electric angle of the rotor position with respect to the axes, p ). In addition, there is a speed sensor 4 on the ASD shaft.

Input blocks 5 and 6 perform direct transformations from phase coordinates "a, b, c to coordinates a, P: block 5 - for stator currents

2 o- f ,, a, Cos 0) t + i t ,, - Cos / co, +

(co, + | -);

- - i y4-sinco / + t ,. -510 (2n

2n hr. “. /, 2l 1 -) - b co, 4 -jj,

  3

6 - for rotor currents

2l

 7 lie / CosY + it, r-Cos.iy, - j) +

+ f ,, .cos (Y. + f-);

i V - r + iir-Sin Y r |) +

+ t ,,. Sin (Y. + f)

The output unit 7 performs the inverse transformation from the coordinates ц, ρ to the phase coordinates "a, b,

and „,, and

COZY, - fya - -Sin-Y,;

 arg

j.rg

and:, .., {/,. „. Cos (Y, -2i) -t / o.SinX

0

.X2l

)

 erg and arg- Cos (Y. -by) - f Sra-SinX

X (,. Hf).

The control inputs of the power supply of the 2 phases of the rotor of the ASD are connected to the outputs of the inverse transform unit 7. The inputs of this unit, in addition to the outputs of the rotor angular position 3 sensor, are connected to the outputs of the stator current regulator 11 along the a axis and the stator current regulator 12 along the p axis.

Negative feedback on the stator current in axis a and the reference signal is applied to the input of the proportional-integral controller 11. This signal comes from a proportional or proportional-integral speed controller 16. The negative speed feedback from the 4-speed sensor and a reference signal is sent to the input of the speed controller. The task signal is received

From the signal source 19 of the manual or automatic control of the drive through the signal setter 18 and the filter 17, this is also done in a controlled DC drive.

, The input of the proportional-integral controller 12 is supplied with negative feedback on the stator current in the p axis and the reference signal. This signal comes from a current reference converter 13, to the input of which a reactive power reference signal is applied to the stator circuit of the ASD. This signal comes from the body of a manual or automatic control of the reactive power of the drive.

The feedbacks on the stator currents in axes a and p are fed to the controllers 11 and 12 from the input unit 5, the functions of which are described above. In addition, positive feedbacks are made to the inputs of these regulators on the components along the axes, and p e. d. the rotor slip of the ASD from the multiplying elements 14 through the dynamic links 15. The transfer functions of the links 15 are selected by the inverse transfer functions of the adjusters 11 and 12, respectively.

The inputs of the multiplying elements 14 are connected to the meter 8 (slip meter) of the synchronous speed difference and the rotor speed, as well as to the meters 9 and 10

rotor flux linkage along axes and p. The components of the flux couplers are fed to the inputs of the stator and rotor currents from the input blocks 5 and 6.

Below are considered the established operating modes of the proposed electric drive (all variables are taken in relative units).

The torque of the ASD and the reactive power of its stator circuit can be determined from the following relationships:

ijf

 W

.

3s

as

: ts

 w - w

Q. 5

Claims (2)

I Ic Is 55 in the case of a sufficiently powerful supply network, it is permissible to assume that / „(Y, const, t / 3 -0. In addition, with a small active resistance of the stator winding, the ASD is obtained that U1 as Oh, f, const. tOs 65 7 / s ys Q; -. / ". In the absence of loading on the ASD shaft, the actual value of the speed равно is equal to the value of co, due to the operation of the speed controller 16. The signal at the output of this controller is zero, and therefore the stator current along the a axis is equal to due to the operation of the current controller 11 : iyg iaso-O, i.e., m 0. Due to the operation of current regulator 12, a current i. ,,, g g-t is maintained in the stator | 3 axis. e. reactive power of the stator circuit is equal to the specified value: P Q. If there is a load on the ASD shaft, a signal appears at the output of the speed regulator (O. Current controller 11 for assigning r, holds, p. Current controller 12 operates in the same manner as described above. Due to positive connections along. and without, the regulators 11 and 12 in the established modes of the electric drive compensate for the slip slip in the rotor windings on the axis of the air. According to their choice of transfer functions of the controls of the currents and speed of the electric drive, they give dynamic properties similar to the properties of a constant electric drive current, re In order to select the transfer functions of the regulators, methods of synthesizing subordinate control systems with successive corrections are applied. Fig. 2 shows the simplified varnant of the proposed electric drive. The effect is achieved by eliminating the current conversion of 6 rotor currents from phase values to synchronously rotating coordinates. In the circuit in Fig. 1, this block is used in the calculation of the flow linkage C (meters 9 and 10). In the simplified scheme, the indicated flux-linked are computed in a simplified way (measurers 9 and 10) using only the stator currents i .j, and g. As mentioned above, it is possible to build a control system based on only rotor currents, i.e., without a conversion unit 5, but with the conversion of a conversion unit 6. All other elements remain unchanged. The subject matter of the invention is 1. An adjustable electric drive with an asynchronized synchronous motor, comprising reversible adjustable sources of power for the phases of the rotor, an angular position sensor of the rotor with respect to a synchronously rotating coordinate system, speed and slip sensors, regulators and sensors of the active and reactive components of the stator current, that, in order to expand the range of speed regulation, to improve the quality of regulation in dynamics, the regulators of the active and reactive components of the current the controller is made in the form of proportional-integral regulators, the auxiliary input of the regulator of the active component of the stator current through the dynamic link of the flexible communication is connected to the output of the multiplying element whose inputs are connected to the meter of the rotor flux-coupling component along the axis of the RNA to the slip sensor, the auxiliary input of the regulator the reactive component of the stator current through a dynamic flexible coupling is connected to the output of the second multiplier element, the inputs of which are connected to the component meter rotor oocoaturation along the a axis and to the slip sensor, while as the measuring components of the rotor flux couplings along the axis of the air, the su.mra elements are replaced, the first inputs of which are connected respectively to the outputs of the stator active current sensors, the second inputs an additional variable converter, the inputs of which are connected to the outputs of the rotor phase current sensors and to the outputs of the rotor angular position sensor with respect to synchronously rotating coordinate axes. 2. The electric actuator according to claim I, characterized in that the input of the setting of the active component of the stator current is connected to the output of the speed regulator (proportional or proportional-integral). fc 77G I I r r r r