JPH03207290A - Driver for brushless motor - Google Patents

Abstract

PURPOSE:To prevent abnormal vibration, damage of a switching element group by measuring a rotation signal time interval from an armature winding to a switching element group, and regarding as being a stepout if it is shorter than the interval at the time of normal to restart it. CONSTITUTION:A time detector 7 for detecting a rotation signal time interval from an armature winding 3 to a switching element group 1 detects a time interval at normal time, and sends it to a microcomputer 6. If a stepout occurs at time T1, it alters to time interval data of D2. Since set time DS having relationship of D1>DS>D2 is stored in the microcomputer 6, if the data D2 is input, an operation signal is interrupted, rotation of a rotary magnet is stopped or and the operation signal, a restart signal are generated to a position detecting rotation controller 5, after a rotary magnet is stopped or after predetermined time. Accordingly, even if the stepout occurs, the restart control is applied immediately to restart its operation.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention detects the relative position of a magnet rotor and an armature winding by an induced voltage applied to a brushless motor and induced in an armature winding. The present invention relates to a drive device for a brushless motor.

(Prior art) Conventionally, this type of brushless motor was
It is described in Japanese Patent No. 19 and has a configuration as shown in FIG. In FIG. 4, 1 is a switching element group, 2 is a brushless motor, and includes an armature winding 3 and a magnet rotor 4. 5 is a position detection rotation control device.

The position detection rotation control device 5 is connected to the armature winding 3, and inputs the induced voltage generated by the rotation of the magnet rotor 4. The zero position detection rotation control device 5 controls rotation based on the input induced voltage. A signal is generated and sent to the switching element group 1 to rotate the magnet rotor 4.

The method of generating the rotation signal is described in detail in Japanese Patent Publication No. 59-36519, and will therefore be omitted here.

(Problem to be Solved by the Invention) However, in the conventional configuration described above, when the load of the brushless motor suddenly changes or a disturbance enters the position detection rotation control device 5, the rotation control signal of the position detection rotation control device 5 is disturbed. , the magnet rotor 4 stops rotating. If the brushless motor falls into a so-called step-out, it becomes impossible to operate the brushless motor.If the brushless motor falls into a step-out, the brushless motor may generate abnormal vibrations or noise, and even a large current may flow through the switching element group 1. There were serious problems such as damage to the switching element group 1 and damage to the power supply device that supplies power to the switching element group 1.

The present invention solves the above-mentioned conventional problems.

It is an object of the present invention to provide a brushless motor drive device that detects step-out and avoids generation of abnormal vibrations and sounds and damage to a switching element group.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a time detector that measures the interval at which signals to the switching element group are detected, and the detected time is longer than during normal rotation. If the length becomes too short, it is regarded as a step-out, and a step-out restart operation is performed to obtain smooth rotation.

(Function) Therefore, according to one aspect of the present invention, a switching element group,
In a brushless motor that has a magnetic rotor and detects a voltage signal generated from an armature winding and controls a switching element group to rotate the magnetic rotor, the interval at which signals are output to the switching element group is measured. A time detector is installed to take advantage of the fact that the signal is input to the switching element group in a much shorter time than during normal rotation when a step-out occurs, and the time detected by the time detector is shortened so that it is recognized as a step-out. , it is possible to perform step-out restart operation and obtain smooth rotation.

(Embodiment) FIG. 1 shows the configuration of a brushless motor drive device in an embodiment of the present invention. In Figure 1, 1
2 is a switching element group, 2 is a brushless motor, 3 is an armature winding, 4 is a magnet rotor, 5 is a position detection rotation control device, 6 is a microcomputer, and 7 is a time detector.

1 to 5 above have the same functions as the corresponding numbers in conventional example FIG. The time from when a rotation signal is output to when the next rotation signal is output is measured and the data is sent to the microcomputer 6.

The microcomputer 6 judges the data sent from the time detector 7, and controls the restart due to step-out when the time is shorter than a predetermined time.

FIG. 2 is a flowchart showing the operation of the embodiment of the present invention, and shows the control performed in the microcomputer 6. As shown in FIG. In Figure 2, first.

The brushless motor is operated by a method such as synchronous signal operation start or positioning start (81). Here, the microcomputer 6 calculates the time from when a certain rotation signal is output from the time detector 7 to when the next rotation signal is output. The microcomputer 6 determines that the detection time is short compared to the internally stored time setting data (S,), and then controls the restart of the step-out. To control the step-out restart, first, the rotation of the brushless motor 2 is stopped (S,), and after confirming that the rotation of the brushless motor 2 has stopped, CBS>, the startup control is performed (S,).
This starting control may be the same as or different from the starting method during operation.

FIG. 3 shows a time chart of one embodiment of the present invention. FIG. 3 shows a signal output from the position detection rotation control device 5 to the switching element group 1, a signal output from the time detector 7 to the microcomputer 6, and a signal output from the microcomputer to the position detection rotation control device 5. The operation signal and restart signal are shown respectively. In FIG. 3, the 0-time detector 7, which assumes that step-out occurs at 1 time T1, constantly sends the detected time to the microcomputer 6. The reference microcomputer 6 sends time detection data D3 to the microcomputer 6 at time T2, assuming that it sends data D□ during normal operation and sends data D3 when it loses synchronization.
For D□>DS>D.

A set time DS having the following relationship is stored, and when the 1-hour detection data D2 is input, the operation signal is cut off, and the rotation of the magnet rotor 4 is stopped or after a certain period of time, the operation signal and restart signal are used for position detection rotation control. emit to device 5. Therefore, even if the engine steps out, restart control is immediately applied and operation can be resumed.

(Effects of the Invention) As is clear from the above embodiments, the present invention has a switching element group formed by three-phase connected armature windings and six semiconductor switching elements with control electrodes connected in a three-phase bridge. , a brushless motor that has a magnet rotor and detects a voltage signal generated from the armature winding to control the switching element group to rotate the magnet rotor, wherein the switching element rotates faster than during normal rotation. According to a brushless motor drive device that detects a step-out by detecting a group input signal and performs a step-out restart operation, it is possible to reliably detect a step-out and prevent the step-out from occurring. It is possible to avoid abnormal vibrations and noise of the brushless motor caused by the brushless motor falling, and furthermore, the drawbacks that a large current flows through the switching element group 1 and damages the switching element group 1 or the power supply device that supplies power to the switching element group 1. This has the effect that the brushless motor can be operated stably.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a brushless motor drive device according to an embodiment of the present invention, FIG. 2 is a flowchart showing the operation of the embodiment of the present invention, FIG. 3 is a time chart of the embodiment of the present invention, and FIG. The figure is a configuration diagram of a conventional brushless motor drive device. DESCRIPTION OF SYMBOLS 1... Switching element group, 2... Brushless motor, 3... Armature winding, 4... Magnet rotor,
5...Position detection rotation control device. 6...Microcomputer, 7...Time detector.

Claims (1)

[Claims] It has an armature winding connected in three phases, a switching element group formed by connecting six semiconductor switching elements with control electrodes in a three-phase bridge, and a magnet rotor, and the voltage generated from the armature winding is In a brushless motor that detects a signal and controls the switching element group to rotate the magnet rotor, step-out is detected by detecting an input signal to the switching element group that is faster than during normal rotation, and the step-out is detected. A brushless motor drive device characterized by restart operation.