JPS5858892A - Controller for commutatorless motor - Google Patents

Abstract

PURPOSE:To enable commutation of a commutatorless motor without interrupting a DC link current by varying the output powers of compensating coil and field coil power converters in a direction for accelerating the commutation of an armature current. CONSTITUTION:Pulse signals A-C of 120 deg. in phase difference and 180 deg. in width obtained through a gate pulse calculator 19 of a reverse converter 4 from a position detector 6 are converted into a constant width signal of 6 pulses per one cycle of a load through an AND circuit 211, an OR circuit 212, an NOT circuit 213, a monostable multivibrator 214 and an OR circuit 215. A phase input signal outputted via the deviation of a compensating coil current from an arithmetic amplifier 218 is selected when the output of the circuit 215 is H level, a throttle phase signal from a throttle phase setter 217 is selected when the output of the circuit 215 is H level, and a field current controller 18 becoming the input signal PH of the gate pulse calculator 22 of a compensating coil power converter 9 is constructed similarly to the compensating coil current control circuit 21.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of operating a fine commutator motor at low speed, particularly for a DC type commutatorless motor. , electric motor bending link electric i! 71' Concerning a control device for a non-commutator motor that can stably commutate the motor current without intermittent current.11-flow type non-commutator motor converts AC-DC power into a H-flat converter. It is common to convert this into a smoothing reactor and supply the ordered power to the armature winding of the motor with a specified phase by a reverse converter. Commutation of ``#@machine current by an inverse converter, that is, straight t゛屹current 111 machine alternating current 1 m
F) '+ a fixed order l2 Therefore, the action of changing is usually '
This is done by the induction ratio of the motor. That is, the arm to be turned off of the thyristor supplying the inverter is turned off by this electromotive force. However, when the motor is stopped or rotating at low speed, stable commutation cannot be performed because this countermotive force is absent or has a small value.

For this reason, conventionally, when rotating at low speed, '! An intermittent starting method is generally used in which the DC link current is intermittent for each commutation of the 4 am current. 1- as a commutatorless motor?
If we consider a 6-pulse type with 6 rotations per cycle, the IFI DC rinsing current must be intermittent 6 times per cycle.The DC circuit usually has an accelerator connected to it. Therefore, the intermittent current takes time to rise and fall, and a sharp intermittent current waveform cannot be obtained. Under such operating conditions, the instantaneous value of the motor's output torque is approximately proportional to the DC link current, that is, the intermittent current value. The higher the intermittent frequency, the greater the amount of pulsation.This may cause rotational irregularities in the motor, or increase in shaft torsional vibration when a torque pulsation frequency that matches the shaft resonance frequency of the mechanical system is applied for a long period of time. There are some unfavorable operating characteristics.Therefore, when using the conventional intermittent starting method, there is a method of outputting an average torque sufficiently smaller than the rated torque,
A method has been implemented in which the frequency range in which intermittent starting is performed is made as narrow as possible.

On the other hand, various known motor structures I: as non-commutator motors have been put into practical use.

An example of this is a so-called synchronous motor with compensation winding, which includes a compensation winding in addition to the armature winding and field winding.

This motor can compensate for armature reaction by flowing a compensation winding current proportional to the armature current, and has advantages such as stable control, increased overload capacity, and quick response, and is suitable for applications with large load fluctuations. It is expected to be applied to applications where rapid acceleration/deceleration is possible. The rotor of this type of motor usually has a laminated iron core, and it can be considered that there is no damper winding in which the field and compensation windings are equally eccentric.

An object of the present invention is to provide a control device for a non-commutator motor that can be operated without using the intermittent starting method at the time of starting when a synchronous motor with a compensation winding 1 is operated as a non-commutator motor. be.

FIG. 1 is a block diagram showing an embodiment of the present invention. The main circuit configuration is a known one, 1,11゜11 is a three-phase power supply, 2 is a transducer, 3 is a DC reactor, 4 is an inverter, numeral is a motor, 51 is an armature winding, 52 is a field. Magnetic winding, 53 is a compensation winding.

6 is a position WIt detector, 2 is a speed detector, 8 is a field winding power converter, and 9 is a compensation winding power converter.

The configuration of the control circuit is as follows: 10 is a speed command, 13 is a speed control circuit, 14 is a current open side circuit, 15 is a gate pulse calculation circuit, and 16 is a field current command.

JT is a field current calculation circuit, 18 is a field winding current control circuit, 19 is a gate pulse calculation circuit, 20 is a compensation winding current calculation circuit, 21 is a compensation winding current control circuit, and 22 is a gate pulse calculation circuit. 23 is a gate pulse calculation circuit M, j4#Is of the inverter 4, and 26 is a current detector.The field winding current control circuit 18 and the compensation winding current control circuit 21 are the gist of the present invention. As an example, a configuration example of the compensation winding current control circuit 21 is shown in the 21st M1m.

211 is an AND circuit, 1111°215 is an OR circuit, 2
13 is a knot circuit, 214 is a monostable multivibrator, 21C is a switch, 21r is a throttle phase setter, 21
81'! Operational amplifier, PH is the phase input signal.

Based on the above circuit configuration, the operation of the 1=compensation winding current control circuit 21 will be explained. , other ridges A, B shown in Figure 2,
C is 120 electrical angles as shown in the characteristic diagram shown in Figure 183.
A ignition pulse for thyristor 1 of the inverter 4 is sent at the time of one up edge and one down edge of each signal with a 180 degree wide pulse having a different dark phase. When the signals A, B, and C pass through the AND circuit 211 and the OR circuit 212, a three-cycle square wave is output from C2 for each cycle of the load. This signal and the knot circuit 213
By inputting the signal passed through the gate to a monostable multivibrator 214 triggered by each up edge and combining it with an OR circuit 215 with seven outputs, a constant width signal of 6 pulses per load cycle is generated as shown in Fig. 3. be superior. On the other hand, the operational amplifier 218 is connected to the compensation winding current calculation circuit 20.
A phase input signal is output based on the deviation between the reference value of the current detector 25 and the detected value from the current detector 25. On the other hand, the throttle phase setter 211 is set to a negative value so that the throttle phase is set.
These two sets of signals are switched by a switch 215 in accordance with the output of the OR circuit 215. When the output of the OR circuit 2 to 5 is at a high level, the throttle phase setter 211 is energized. Therefore, as shown in Fig. 3, the symbol PH is a negative constant value for a predetermined period of time from the time when the gate firing pulse of the inverse converter 4 is given, and for other times of 7, the value of the operational amplifier is The output is output as is.This signal is generated using the cosine wave control method, that is, the dominant delay angle of the thyristor of the compensation winding power converter 9.
The phase l2 determined by PHKCosdc becomes the signal for firing.

FIG. 4 shows a detailed explanation of the present invention in which the armature winding current is conducted in the positive direction in the U phase and in the negative direction in the W phase. In this figure, the relative position of the stator and rotor is such that the effective commutation advance angle β is 30 degrees and represents the position immediately before the positive current commutates from the U phase to the V phase. At this time, the compensation winding current IC and the field winding current 1f flow in a direction that cancels the reaction of the armature current in the electric machine, and the direction coincides with the motor magnetic flux φμ field winding axis. In this state, a gate firing pulse is sent to the thyristor of the armature V phase. Simultaneously, the compensation winding current is changed in a direction 52 to decrease from the current direction. During the commutation period, the U-phase and V-phase windings of the motor are short-circuited, and if you try to reduce io at this time, the U-phase current will increase due to the transformer action of the armature and rotor side windings. decreases. In other words, the magnetic flux of the motor cannot change suddenly due to large actance.

This is a station where the armature-side and two-rotor-side winding currents change mutually so as to keep the magnetic flux constant. On the other hand, since the DC link current of the non-commutator motor has a substantially constant value, the V-phase current increases by the amount that the U-phase current decreases, thereby performing commutation operation. Note 1
In this actual weaving example, the phase input is changed to give a change in io at the time of commutation, but the same effect can be obtained even if the flow reference value is changed.
’-like actions. In the explanation of section 1, the case was described in which a means for changing the compensation winding power was provided, but the configuration of the field winding current control circuit 18 in FIG. 181 is also the same as that shown in FIG. It suffices if the set value of the setting device 211 is set to a positive value minus the direction in which the field current 1f is increased. That is, based on the idea from FIG. 114, it is sufficient to increase if in order to increase the V-phase current.

In this way, the present invention utilizes the mutual transformer action between the armature and rotor windings to transfer the armature current, and is stable even without using the induced voltage caused by the rotation of the motor. It is possible to perform a suitable commutation. As a means of commutation operation using transformer action, it is possible to consider a method using only a power converter for compensation winding, a method using only a power converter for field winding, or a method using both in combination.
Either method may be used.

Further, the torque pulsation in this operation is similar to that in normal operating conditions because the DC link current is almost constant and there is almost no distortion of the magnetic flux during commutation. Therefore, the operation according to the present invention is performed in the range where intermittent starting has conventionally been performed, and when the back electromotive force is established, the normal operation mode C is started.
: By switching, it is possible to perform safe operation with less torque pulsation over the entire speed range.

[Brief explanation of the drawing]

FIG. 131 is a block diagram showing one practical example of the present invention, and FIG. 2 is a block diagram of the compensation winding current control circuit of FIG. 1. Figure 3 is a signal time characteristic diagram for explaining the operation of the circuit in Figure 2. Figure J4 is a model diagram of motor energization for detailed explanation of the present invention. 1.11.12... Three-phase power supply, 2... Olfactory transducer. 3...DC reactor, 4...Inverse converter, mutual...
Electric motor, 6... Position detector, 7... Speed detector, 8
... Field winding power converter, 9... Compensation winding power converter. 10... Speed command device, 13... Speed control circuit, 14
...Current control circuit, 15, 19.24...Gate pulse calculation circuit, 16...Field current command device, 11...
Field current calculation circuit, 18... field winding current control circuit,
20... Compensation winding current calculation circuit, 2)... Compensation winding current control circuit. 2. Illustration 3. 4. Cause U - W

Claims (1)

[Claims] A synchronous motor having an armature winding, a field winding, and a compensation winding; In the first means for changing the output power of the power converter that supplies power to the compensation winding by the rotation mr timing transmission of the tortoise armature current. A second means for changing the output power of the motor is provided in the direction of promoting commutation of the armature current in the low speed rotation region of the motor. Compensation winding by means of membrane combination.By changing the power of the field winding, the commutation of the armature current can be achieved without continuing the DC link current of the power converter for the child winding. A control device for a no-kilometer motive that allows you to hit the ball.