JPS6335182A - Driving device for reluctance motor - Google Patents

Abstract

PURPOSE:To prevent the runaway of a motor after generating an abnormality, by braking positively by the detection of the abnormality at first, then, stopping the supply of an exiting driving current. CONSTITUTION:When an abnormality is generated in the driving condition of a reluctance motor, an abnormality signal is outputted from abnormality detecting means 1. A speed command circuit 4 receives the abnormality signal and supplies a speed zero command signal to a motor drive control circuit 7. The motor drive control circuit 7 supplies an exciting drive current so as to nullify the rotation of the motor. When the motor is stopped and an actual speed zero signal is inputted to an AND circuit 10, the supply of the exciting drive current for the motor is stopped. The abnormality signal from the abnormality detecting means 1 is supplied also to a delay circuit 5: when a predetermined time has elapsed, an output signal as an exitation stopping signal is given to a motor exciting and drive circuit 9 through an OR circuit 12.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a reluctance motor drive device, and in particular, a protection function that prevents runaway by effectively stopping the reluctance motor when an abnormality occurs. The present invention relates to a drive device having:

[Conventional technology]

In conventional motor drive devices, when an instantaneous overcurrent flows, the autoload state continues for more than a predetermined time, or a power supply abnormality occurs, these abnormalities are detected and motor excitation is stopped. was. For example, in a permanent magnet type synchronous motor, by short-circuiting the armature winding, deceleration is applied through regeneration, and rotation can be quickly stopped.

[Problem that the invention seeks to solve]

However, since reluctance motors do not use permanent magnets, regenerative braking is not applied even when the motor is de-energized, resulting in free running. Therefore, even though the abnormality detection means detects an abnormality, it is not possible to quickly stop the rotation of the motor.

[Means for solving problems]

The reluctance motor drive device of the present invention has been made in view of the above problems, and includes an abnormality detection means that outputs an abnormality signal when an abnormality in the reluctance motor and its drive circuit is detected, and a speed command signal based on external human power. a speed command circuit that outputs a speed command signal indicating a zero speed instead of a speed command signal based on an external input when the abnormal signal is inputted, and an actual speed signal representing the actual motor rotation speed and the speed command signal. A motor drive control circuit that detects the speed difference between the actual speed and the commanded speed and outputs a motor drive control signal according to this speed difference, and an actual speed zero signal that indicates that the actual rotational speed is zero and the above-mentioned abnormality. an excitation stop command circuit that outputs an excitation stop signal when a signal is input or when a certain period of time has elapsed after inputting the abnormal signal; and an excitation stop command circuit that supplies an excitation drive current to the motor based on the drive control signal and excitation the motor. and a motor excitation drive circuit that stops supplying the excitation drive current when a stop signal is input.

[Effect]

When an abnormality occurs, a speed command signal for reducing the rotational speed to zero is output from the motor drive control circuit to the motor drive circuit. Thereafter, when the motor stops or a certain period of time has elapsed, an excitation stop signal is output from the excitation stop command circuit to the motor excitation drive circuit, and the supply of excitation drive current to the motor is stopped.

〔Example〕

Hereinafter, the present invention will be described in detail along with examples.

The figure is a block diagram showing an embodiment of a reluctance motor protection device according to the present invention. The abnormality detection means 1 is composed of various sensor means 2a, 2b, 2c, etc. and an OR circuit 3. Each sensor 2a, 2b, 2C normally outputs a "low" level signal, but when an abnormality is detected, When detected, the output signal is set to "high" level. For example, sensor 2a
The sensor 2b outputs a "high" level when the instantaneous overcurrent (overcurrent) exceeds a predetermined value, and the sensor 2b outputs a "high" level when a current exceeding a predetermined value flows within a predetermined time, that is, when there is an overload. The sensor 2C outputs a "high" level when an abnormality occurs in the power supply. Therefore, when the abnormality detection means 1 detects any abnormality, it outputs an abnormality signal ("high" level). An output terminal of this abnormality detection means 1 is connected to one input terminal of a speed command circuit 4 and an input terminal of an excitation stop command circuit 13.

The speed command circuit 4 supplies a speed command signal to the motor drive control circuit 7 based on an external command inputted from a terminal 6, and when an abnormality signal is inputted from the abnormality detection means 1, the speed command signal is converted into a speed command signal based on the external input. Instead, a speed command signal indicating zero speed is output and supplied to the motor drive control circuit 7.

The motor drive control circuit 7 compares the speed command signal from the speed command circuit 4 and the actual speed signal input from the terminal 8, outputs a motor drive control signal corresponding to the speed difference, and outputs a motor drive control signal corresponding to the speed difference. supply to. When the speed command signal is larger than the actual speed signal, the motor drive control signal is a positive value;
Conversely, when it is small, a negative motor drive control signal is given.

The motor excitation drive circuit 9 supplies an excitation drive current to a reluctance motor (not shown) based on a motor drive control signal from the motor drive control circuit 7 .

Further, when the motor excitation drive circuit 9 receives an excitation stop signal from the excitation stop command circuit 13, it stops supplying the excitation drive current regardless of the motor drive control signal.

The excitation stop command circuit 13 includes a delay circuit 5 and an AND circuit 10.
and an OR circuit 12.

The AND circuit 10 takes the logical product of the abnormality signal from the abnormality detection means 1 and the actual speed zero signal (“high” level) from the terminal 11, and its output terminal is connected to one input terminal of the OR circuit 12. It is connected. The delay circuit 5 delays the abnormality signal from the abnormality detection means 1 for a predetermined period of time, and has an output terminal connected to the other input terminal of the OR circuit 12.

The output terminal of the OR circuit 12 is connected to one of the input terminals of the motor excitation drive circuit 9, and the output terminal of the OR circuit 12 outputs an excitation stop signal (“high” level).

Next, the operation of this embodiment configured as described above will be explained. The speed command input from the terminal 6 is given to the motor drive control circuit 7 via the speed command circuit 4, and here, the speed command is inputted to the terminal 8.
The motor excitation drive circuit 9 is compared with the actual speed signal inputted from the motor excitation drive circuit 9, and a drive control signal corresponding to the speed difference is provided to the motor excitation drive circuit 9. The motor excitation drive circuit 9 applies an excitation drive current to a reluctance morph (not shown) based on a drive control signal to drive it.

If an abnormality such as overcurrent occurs in such a driving state,
An abnormality signal (“high” level) is output from the abnormality detection means 1 and is supplied to the speed command circuit 4. The speed command circuit 4 receives the abnormality signal and supplies a zero speed command signal to the motor drive control circuit 7. The motor drive control circuit 7 outputs a motor drive control signal to reduce the actual speed to zero while monitoring the actual speed signal input from the terminal 8, and the motor excitation drive circuit 9 controls the motor drive control signal based on the motor drive control signal. Supplies an excitation drive current that makes the rotation of the motor zero.

On the other hand, the abnormality signal (level ``)1a'') from the abnormality detection means 1 is also supplied to the AND circuit 10. However, while the above-described motor stopping operation continues, that is, while the motor is rotating, the actual zero speed signal is not input to the terminal 11, so the output of the AND circuit 10 is maintained at a "low" level. Then, when the motor stops and the actual speed zero signal is input to the other input terminal of the AND circuit 10, the output signal becomes a "high" level. This signal state is given as an excitation stop signal to the motor excitation drive circuit 9 via the OR circuit 12, and the supply of excitation drive current to the motor is stopped.

The abnormality signal from the abnormality detection means 1 is also supplied to the delay circuit 5, and when a predetermined time has elapsed, an output signal as an excitation stop signal is applied to the motor excitation drive circuit 9 via the OR circuit 12. The excitation stop signal output from the delay circuit 5 is effective when there is an abnormality in the detection of zero rotation speed and the actual zero speed signal is not input to the terminal 11 even though the motor rotation has stopped. be.

〔Effect of the invention〕

As explained above, according to the reluctance smorph drive device of the present invention, when an abnormality occurs, the motor drive control circuit outputs a speed command signal for reducing the rotational speed to zero to the motor excitation drive circuit, and then the motor stops or
Alternatively, when a certain period of time has elapsed, an excitation stop signal is output from the excitation stop command circuit to the motor excitation drive circuit, and the supply of excitation drive current to the motor is stopped.

In other words, unlike conventional drive devices, the supply of excitation drive current is not immediately stopped upon detection of an abnormality, but braking is first actively applied and then the supply of excitation drive current is stopped. There is no runaway of the motor after an abnormality occurs, and the supply of excitation drive current can be automatically stopped.

[Brief explanation of the drawing]

The figure is a block diagram showing one embodiment of the present invention. 1... Abnormality detection means, 4... Speed command circuit, 5...
- Delay circuit, 7... Motor excitation drive circuit, 9... Motor excitation drive circuit, 13... Excitation stop command circuit.

Claims (1)

[Claims] Abnormality detection means outputs an abnormality signal when detecting an abnormality in the reluctance motor and its drive circuit, and outputs a speed command signal based on an external input, and when the abnormality signal is input, the abnormality detection means outputs a speed command signal based on the external input. A speed command circuit outputs a speed command signal indicating zero, an actual speed signal representing the actual motor rotation speed, and a speed difference between the actual speed and the command speed from the speed command signal, and the motor is driven according to this speed difference. A motor drive control circuit that outputs a control signal, an actual speed zero signal indicating that the actual rotational speed is zero, and excitation when the abnormality signal is input or when a certain period of time has elapsed after inputting the abnormality signal. An excitation stop command circuit that outputs a stop signal, and a motor excitation drive circuit that supplies an excitation drive current to the motor based on the drive control signal and stops supplying the excitation drive current when the excitation stop signal is input. A reluctance motor drive device.