SU1410211A1 - Multimotor electric drive - Google Patents

Abstract

The invention relates to electrical engineering and can be used to synchronously rotate mechanically uncoupled shafts in a wide range of load variations. The aim of the invention is to increase the dynamic performance. For this purpose, a correction circuit 9, a circuit 10 for separating the maximum angular mismatch are entered into a multi-motor electric drive, and the semiconductor switch 8 is equipped with an input 11 for adjusting the tuning angle connected through a correction circuit 9 to the output of the circuit 10. The inputs of circuit 10 are connected to the outputs of sensors 4-6 rotors of synchronous motors 1-3. As a result, in all control modes of a multi-motor electric drive, the process of switching to the new value of the maximum angle error is accelerated and overshoot is eliminated when switching to a new mode of operation due to a change in load on one of the engines 1-3. 3 il. S SL

Description

: The invention relates to electrical engineering, in particular, to electric power of jIal, and can be used for synchronous rotation of mechanically uncoupled shafts in a wide range of load variation.

I The aim of the invention is to increase the 4 dynamic indicators.

I FIG. 1 shows a structural Q scheme of a three-motor electric drive; in fig. 2 is a schematic of the maximum angular inconsistency; In Fig 3, the time diagrams of the signals at the output of the elements of the electri- fs water.

The multi-motor electric drive contains N synchronous motors 1–3 (Fig. 1), each of which is equipped with rotor positioners 4–6, and circuit 7 for the separation of the signals of the rotor motor position sensor, the codes of which are connected to the outputs of the 4-6 positions of the rotor, and the output is connected to the input of the semiconductor 25 to | switch .8. The output of the switch 3 is connected to the root windings of synchronous motors 1-3, besides the electric drive contains a correction circuit 9 and a circuit 10 for maximizing the horizontal error, and the semiconductor switch 8 is provided with an input 11 for adjusting the angle of adjustment. Scheme 10 for maximal angular alignment ratios includes N + 1 RS-flip-flops 12-15 (Fig. 2), logical elements N OR 16 ;, N And 1 7 with direct AND inverse outputs 2 and 18. The output is element 2I 18 is connected to the input of the setpoint of the logical unit

(: N + 1) -ro of the RS flip-flop 15, the output of the i-oporo is the output of the maximum angular mismatch circuit 10, which through the correction circuit 9 is connected to the input 11 of the control angle of the commutator 8. Inputs of the setpoint logical zero RS-flip-flops 12-15 are combined and connected to the forward output of the logic element N And 17, the inputs of which are combined with the same input 50 of the logic element N OR 16 and are connected respectively to the outputs of the RS-flip-flops 12-14. The setpoint inputs of the logic unit of the RS-flip-flops 12-14 form the corresponding inputs of the circuit P | Odklyuchenny to the outputs of the sensors 4-6 rotor position. The output of the logic circuit N IZH 16 and the inverse output logi40

The IC circuit NI17 is connected to the input of logic circuits 2I18.

Multi-motor drive works as follows.

In the steady-state mode, the rotor of one of the engines, for example, the rotor of the engine 1 lags behind the rotors of the ostginsky engines by the angles π, π and let (fig 3). In this case, in accordance with the principle of operation of the separation circuit 7 signal of the rotor motor positioning sensor, the pulse sequence I is received from the sensor 4 of the motor 1 at the input of switch B, and the signal at the control input of the setting angle of switch 8 is zero. Then the motor 1 is the leader in the group or the leader and is in the self-switching mode with the zero setting angle of the switch, and the remaining motors are the slave and are in the stepping mode.

The mean value of the electromagnetic moment MD, developed by the motor 1, on the inter-switching interval is equal to

about 2. l Me, Meo7 2 where D is the intercommutation interval

(in e-radians);

Mao is the maximum value of the electromagnetic moment. The average value of the electromagnetic moment of the MDO developed by the jth motor in the stepping mode is determined by the expression.

M M3Q - sin () cos

in steady-state mode dl. all gamblers, equality is true (pg

3J MHi + | - c ,,:.

e MC- - moment of load on the j-th

engine;

QO is the average angular velocity of the engine at the inter-switching interval. in steady state; equivalent flux coupling of one synchronous motor;

R is the active resistance of the winding of a synchronous motor, and, the closer the load moment value to

five

ten

15

The jth motor to the value of the load moment on the driving motor, the smaller the value of &

In addition, in the steady-state mode, the pulses at the input of the selection circuit 10 of the maximum angular mismatch have a constant duration and the signal at the output of the correction circuit 9 at the moments of switching has a zero value, which determines the zero setting angle of the switching. Suppose now that for some reason the ratio of the load moments of the engines has changed, for example, the load moment of the engine 3 has increased. This will cause a gradual decrease in the current value of the angle mismatch, which in turn leads to a gradual decrease in the pulse output pulse (10 (And , e) making the maximum angle mismatch and to the occurrence of a negative voltage at the output of the correction circuit 9. The negative voltage at the input 11 of the control angle of the semiconductor switch Torus 8 translates it into the mode of the lagging commutation of the leader with an angle of 30.3 on the scale 6, proportional to this negative voltage. Then the average values of the electromagnetic moments on the inter-switching interval.

20

25

the engines developed will be a descriptive reduction of the mismatch due to the expressions

l

MS, (|) soz;

engine angle 3 and reduces overshoot to misalign the angle, although it does not exclude it at all. Tracing this situation, we will come

% Mao | sin- (|) cos (4 M j +9),

where j 2,3.

The lagging switching of the leader leads to a decrease in the electromagnetic moment developed by each motor, but the relative decrease in the moment for each of them is different: for the leader

Ma oh,

er for the rest of the slave engines

MaJ.cos ()

Mlj cos Aifj Therefore, the most noticeable will be the reduction in torque for an engine with a maximum angular mismatch, and it is for him that the transition to a new angle mismatch value will be accelerated. This process will continue until

0

five

ABOUT

0

five

while this engine 3 has a maximum angle mismatch and while it decreases. If the engine angle mismatch 3 changes so much that it is not the maximum, then the system will switch to testing the signal from another motor that has the maximum mismatch, and the motor angle difference mismatch 3 is no longer monitored until for some reason it will not be maximized again. I

If the angle mismatch of the engine 3 remains maximal for the whole group of engines, it will decrease until the average value of the electromagnetic moment of the engine 3 at the inter-switching interval approaches the value required for rotation of the engine 3 at the same speed as the leading engine . When this happens, the angle mismatch will cease to decrease, and at input 1.1 of the switching angle of the semiconductor switch 8, the voltage will gradually approach the zero value, and the switching setting angle will also approach zero, which will increase the electromagnetic moment of all motors, and this in turn, prevents excessive reduction of mismatch on

engine angle 3 and reduces overshoot to misalign the angle, although it does not exclude it at all. Tracing this situation, we will come

Consider the situation when the commutation setting angle is zero, and the angle mismatch of the engine 3 should increase, for example, when it is adjusted during the testing

increased load torque. An increase in motor mismatch 3 leads to the appearance of a positive voltage at the control input of the commutation setting angle of the semiconductor switch 8. In this case, the driving motor switches to the forward switching mode with the setting angle 0, the average electromagnetic moment at the inter-switching interval at the driving motor decreases, and for the engine 3 with the maximum angle misalignment it increases, which allows to force an increase in its mismatch

5. 14

net corner. When approaching the misalignment in angle to the value, it is necessary for Mjf to rotate engine 3 at the same speed as the driving motor, the signal at the output of circuit 9 cor- cularly decreases to zero, causing an increase in the average value of e; the electromagnetic moment of the leading DE | igatel and reducing it at the engine 3 with a maximum angle mismatch ei, which, in turn, in this situation reduces the overshoot for the angle mismatch.

j

I Lack of control over the mismatch of the angle of the engines, for which the condition is satisfied

.c

affects the common-mode rotation mode

nor the entire group of engines, since this mode can only be disturbed by moving with a maximum misalignment ei in the angle.

 Consequently, in both cases, the device accelerates the process of transferring the new value of the maximum p4 agreement in the angle and improves

Damic indicators of the proposed

motor-driven electric drive.

F

formula image shadows

I Multi-motor electric drive, С (Jarger N synchronous motors, each of which is equipped with a rotor position sensor, the output circuit C1 of the rotor position sensor I and the lagging engine, whose inputs

116

associated with the outputs of the rotor position sensors, and the output is connected to the input of a semiconductor switch, the output of which is connected to the main windings of synchronous motors, characterized in that, in order to improve the dynamic performance, a circuit is introduced

correction, the maximum angular mismatch isolation circuit, and the semiconductor switch is equipped with an adjustment angle adjustment input, the maximum angular mismatch isolation circuit is composed of N + 1 RS flip-flops and logic elements N OR, N AND with forward and inverse outputs, logic 2I, the output of which is connected to the installation input, of a logical unit (N + 1) -ro RS-trigger, whose output forms the output of the maximum angular mismatch circuit, which is connected to the angle adjustment input switch settings through the correction circuit, the setpoint inputs of the logical zero of all RS-flip-flops are combined and connected to the direct output of the N logic gate. And the inputs of which are combined with the same inputs of the N-OR logic gate and connected respectively to the RS-trigger outputs, the inputs of the logical unit which form the inputs of the allocation circuit of the maximum angular error, connected respectively to the outputs of the rotor position sensors, and the output of the logic circuit N OR and the inverse output of the logic circuit N AND , are connected to the inputs of logic circuit 2I.

FIG. g

Claims (1)

A multi-motor drive containing N synchronous motors, each of which is equipped with a rotor position sensor, a circuit for extracting the signals of the rotor position sensor of the jet engine, the inputs of which are connected to the outputs of the rotor position sensors, and the output is connected to the input of the semiconductor switch, the output of which is connected to the armature windings of synchronous motors , characterized in that, in order to increase dynamic performance, introduced a correction scheme, a scheme for highlighting the maximum angular mismatch, and a semiconductor The nickel switch is equipped with an input for adjusting the angle of adjustment, and the maximum angular misalignment allocation circuit is composed of N + 1 RS-flip-flops and logical elements N OR, N AND with direct and inverse outputs, logic element 2I, the output of which is connected to the installation input, logical unit ( N + 1) -ro RS-flip-flop, the output of which forms the output of the maximum angular misalignment allocation circuit, which is connected to the angle control input ^- the switch settings through the correction circuit, the logic zero settings of all RS-t the triggers are combined and connected to the direct output of the logical element N AND, the inputs of which are combined with the same inputs of the logical element N OR and connected respectively to the outputs of the RS-triggers, the installation inputs of the logical units of which form the inputs of the maximum angular error detection circuit connected respectively to the outputs of the position sensors rotor, and the output of the logic circuit N OR and the inverse output of the logic circuit N AND are connected to the inputs of the logic circuit 2I.