JPS59106891A - Rotary electric machine - Google Patents

Abstract

PURPOSE:To accurately perform a speed control by increasing or decreasing the current command value of a commutatorless motor by a low or high speed switching signal in the amount corresponding to the variation in the torque, thereby minimizing the variation in the torque at the low or high speed switching time. CONSTITUTION:A low or high speed signal generator 17 is set at its output to ''1'' at the low speed time and to a value for supplementing the variation in the torque at the high speed time, and a suitable current command signal is fed to a current limiter 9 by a multiplier 16 without varying the output of a speed control amplifier 8. In other words, the generator 17 for obtaining the output of a low or high speed discriminator 15 does not perform the signal correcting function of the multiplier 16 at the low speed time, and multiplies by the multiplier 16 the output value of the amplifier 8 by the output value corresponding to the variation in the torque of the generator 17 at the high speed time. Accordingly, the armature current can be increased by the current command obtained by adding the current correcting value corresponding to the variation in the torque without increasing the output of the amplifier 8 at the high speed switching time.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a control device that completely reduces torque variation IMJ that occurs when switching the motor control advance angle (hereinafter referred to as β angle) of a non-commutated motor.

In general, a synchronous motor and a distributor detect the rotor position signal of the synchronous motor, and the distributor sends out a signal to obtain the AC power.
Commutatorless motors are commonly used without the main component being a power converter for supplying power.

As a control device a for this type of commutatorless motor, the one shown in FIG. 1 is widely known.

Fig. 1 is a block diagram showing a typical circuit configuration of a conventional example. 5 is an acceleration/deceleration regulator, 6 is a speed detector, 7, 7' is a controller, 8 is a speed III control amplifier, 9 is a current limiting circuit,
10 is '? 4 is a flow nuclear ejector, 11 is electric 1c system 1I111
12 is an α angle control circuit, 13 is a logic circuit, 14 is a torque discriminator, and 15 is a low speed discriminator. Here, the acceleration/deceleration regulator 5 inputs the output of the speed setter 4 to adjust its acceleration/deceleration characteristics, and as a result, realizes a gentle electric-like speed control operation. Further, the torque indicator 4 provides a signal for determining whether the motor is on the power side or the regeneration side.

The reading power of such a thing is well known and explained in detail.The current if and if are given through the limit circuit 9, and the α angle control circuit 12 controls the phase of the cycloconverter 3 to supply power. Become.

Here, the low/high speed discriminator 15 obtains the output of the speed detector 6, determines whether the speed is low or high, which is approximately (1/10 to 1/20) of the normal rated speed, and uses the low/high speed switching time signal as a logic circuit 13. give to From this, each output of the α angle control circuit 12, distributor 2, torque discriminator 14, and low/high speed discriminator 15 is added to the logic circuit 13 to control the cycloconverter 3, and the cycloconverter 3 and the synchronous motor 1 control the output. The speed of the commutator motor can be controlled. When the non-commutator electric motor is operated under high force, the β angle can be switched by the combination of the signals from the torque discriminator 14 and the low/high speed discriminator 15.

That is, in the low speed range, the β angle is set to almost zero in order to increase the starting torque, and in the high speed range where the motor speed has increased to a certain extent, the β angle is set to approximately zero in order to ensure the commutation margin of the cycloconverter 3. It is normal to advance the angle to a value of 60°. Then, due to this β angle switching, the electric motor torque is reduced to about (1/2), causing torque fluctuations during acceleration and deceleration. FIG. 2 is a waveform diagram showing a general torque waveform. TL, 'I'11 is (β-o0 electric commutation system #).

(load commutation control with β=600). It goes without saying that the conventional system is to use power supply commutation at low speeds and perform negative commutation at higher speeds. In this way, switching from low speed to high speed causes torque fluctuation.

Further, in FIG. 3, state changes during low/high speed switching are shown. That is, the low speed side and high speed side H shown in (a)
For the switching operation, (bl has armature box 61f, IM
(cl shows the comparative relationship between the speed setting NO and the motor speed N.

As described above, when torque fluctuation occurs during speed control, the actual speed is accelerating while almost corresponding to the speed setting as shown in Fig. 3(c), and when switching from low speed to high speed. When torque fluctuations occur, even if the armature current is adjusted to match the torque fluctuations, there is a problem in that speed fluctuations occur due to the delay in the speed control system.

The present invention has been developed with the above-mentioned points in mind.The present invention utilizes a simple additional device to increase or decrease the current command by the proportion of the torque fluctuation in order to minimize the torque fluctuation during low-to-high speed switching. A special device is provided which uses a high speed switching method. Hereinafter, the present invention will be explained with reference to embodiment drawings similar to the apparatus shown in FIG.

FIG. 4 shows a circuit configuration of an embodiment to which the present invention is applied, in which 16 is a multiplier and 17 is a low-speed signal generator. In the figure, the same reference numerals as in FIG. 1 indicate parts having the same function.

That is, if the circuit configuration shown in FIG. 4 is compared with that shown in FIG. , a low-high-speed signal generator 17 which receives the output of the low-high-speed discriminator 15 as input is further added, and this low-high-speed signal generator 1
7 output is provided as the other input signal of the multiplier 16.

Next, the operation of this part will be explained using a specific example to make it easier to understand.The low-high-speed signal generator 17 has an output that is reset to "1" at low speeds and a torque fluctuation at high speeds. If it is set to a value that compensates for the minute,
Multiplier 1 without changing the output of speed control amplifier 8
6, a more suitable current command signal can be sent to the current limiting circuit 9. In other words, the low-high-speed signal elder l:lE unit 17 that obtains the output of the low-high-speed discriminator 15 does not perform the signal correction function of the multiplier 16 at low speeds, and furthermore, at high speeds, the signal value of the speed control amplifier 8 output is determined by the multiplier 161. The value commensurate with the torque fluctuation l of the output of the low-speed signal generator 17 is reduced by 4J1, and it acts to generate this output. For this reason, if described based on the above-mentioned Figure 3, the current correction value corresponding to the torque fluctuation is added without increasing the speed control amplifier 8 output during high-speed switching. 'Nao Isogo's first class IM will continue to grow. In this way, by increasing the armature box a, disturbances in the speed control system can be suppressed to a minimum, and the correlation setting NO and the electric current speed N correspond to each other, so that acceleration can be achieved. Furthermore, it is clear that by arranging the multiplier 16 before the current limiting circuit 9 in this way, it can operate effectively without changing the maximum value of the current command and without completely impairing the function of the current limiting circuit 9. .

As described in detail above, according to the present invention, the current command value of the electric motor is changed by a value commensurate with the torque fluctuation by the low/high speed switching signal.
- It is possible to provide a device that has the function of increasing or decreasing speed and can realize highly accurate speed control.

For convenience of explanation, we have used a typical example of the cycloconverter system; however, the present invention is not limited to this, and the power converter section may also be composed of a converter and an inverter, and furthermore, other control means may be used. It goes without saying that the present invention is applicable even to a control system to which a control system is added.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a typical circuit configuration of a conventional example.
2 and 3 are torque waveform diagrams shown for explanation of FIG. 1, diagrams for explaining state changes during low-speed switching, and FIG. 4 is an embodiment similar to the device shown in FIG. 1 to which the present invention is applied. FIG. 1. Same J4J] Electric motor, 3. Zychroconverter, 8 Speed control amplifier, 9-. Current limiting circuit, 11-
First-class control amplifier, 15--Low-high speed discriminator, 16- Multiplier, 17- Low-speed signal generator. Patent applicant Toyo Denki Manufacturing Co., Ltd. Representative Atsunuma Doi Figure 2 Figure 3 Figure d

Claims (1)

[Claims] In the control device of a non-commutated electric 1JJJ machine that has a function of switching the motor control advance angle when transitioning from low speed to high speed in synchronous 'it operation, a signal lid corresponding to the torque fluctuation is generated by the output command of the low and high speed discriminator. and a multiplier that multiplies the current command input value and a signal lid corresponding to the torque fluctuation, and is configured to send the output of the multiplier as a current command signal. Non-commutator 11i, motive control device 0