JPS61135378A - Brushless motor drive device - Google Patents

Abstract

PURPOSE:To stably operate a motor at switching time by starting to rotate by increasing a signal from rotating magnetic field generating means and a power source voltage within a low voltage due to a synchronizing signal of the prescribed frequency and generating a switching signal after detecting the rotation. CONSTITUTION:A brushless motor 3 having a magnet rotor 5 is rotated by controlling the energization and the interruption of an armature winding 4 by semiconductor switching group 2. After starting command means 12 generates a signal, a period signal of the prescribed frequency is input from generating means 8 to rotating magnetic field generating means 9 to form 3-phase synchronizing signals 9-U-W phases displaced at 120 deg.. This is input to switching means 11, and the group 2 is controlled through the means 12. Further, the drive power source 1 of the motor 3 is increased within low voltage to forcibly rotate a magnet rotor 5. Thus, an induced voltage is generated by the rotation of the rotor 5, after the prescribed time is elapsed, switching means 10 is switched by a switch command by the means 10, the position detection signal of the rotor 5 is output from comparator group 7 to the means 12 to normally rotate.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a brushless motor, and in particular detects the relative position of a magnet rotor and an armature winding based on an example of the induced voltage induced in the armature winding. [#J is related to a brushless motor for stable rotation.

2. Description of the Related Art A conventional brushless Morph drive device of this type has a configuration as shown in FIG. This configuration was created in 1984.
This is an example described in Japanese Patent Publication No. 36519 and Japanese Patent Publication No. 59-38520, and has a three-phase configuration.

For convenience, a three-phase example will be used for explanation below.

In other words, the output end of the semiconductor commutake device 2 formed by three-phase bridged six semiconductor switching element groups 201 to Q6 on both ends of the DC power source is connected to the input end of the armature winding 4 of the motor body 3. . Using the induced voltage signal induced in the armature winding 4 by the rotation of the magnet rotor 5, the control means 12 converts it into a signal for energizing or cutting off the semiconductor switching element group 2 in the semi-dedicated commu-taking device, thereby causing the magnet to rotate. Rotate the child steadily. In addition, as shown in FIG. 6, induced voltage signals induced in the armature winding 4 4-U phase, 4-
Since spike noise is generated in the V phase and 4-W phase when the semiconductor switching element group 2 is turned on and off, it is removed by the signal conversion means 6, and triangular wave-like signals 6-U phase and 6- with a 90° phase delay are generated, respectively. Comparator group 7, which is a position detection circuit, detects the magnitude of each phase and the virtual neutral point signal which is converted into V phase and e-w phase and synthesized with a resistor from each three phases. (explained as a group).

In this conventional example, as can be seen from the waveform diagram in Fig. -U phase signal 7-
W-phase output signals are created, and each of them is 12
They are square waves with a 0° phase shift, and these signals are input to the switching means 11 as rotor position detection signals. During steady rotation, they are output to the control means 12 and are controlled by semiconductor switching elements based on the logic levels of the three phases. Controls energization and cutoff of group 2. With this method, the signals of each phase input to the comparator group 7 follow the load fluctuations accordingly, so stable operation can be maintained.At the time of startup, the magnet rotor 5 is in a stopped state. Since the induced voltage is not generated in each phase, the output signal of the synchronizing signal generating means 8 is inputted to the rotating magnetic field generating means 9 after the signal from the start command means 14 is generated.
Three-phase synchronous signal with phase shift 9-U phase, 9-V phase, 9-W
Create a phase. These three-phase homogeneous signals are input to the switching means 11, and at the time of startup, these signals are output to the control means 12 to generate a rotating magnetic field in the armature winding and forcibly rotate the magnet rotor. When the magnet rotor 5 rotates, an induced voltage is generated in the armature winding 4, so that rotation of the magnet rotor can be detected. After detection, the output signal from the switching means 11 is switched to the output signals 7-U phase, 7-V phase, and 7-W phase of the comparator group 7 by the signal of the switching command means 10, and the motor 3
rotates steadily. Furthermore, until the 3-phase synchronous signal after startup is switched to the 3-phase induced voltage signal of the comparator group 7, the motor is driven as a synchronous motor, and the frequency of the output signal of the synchronous signal generating means 8 is increased with time, and the 3-phase synchronous motor is It is common that the frequency of the phase synchronization signal also increases to accelerate the magnet rotor. This is because the magnet rotor 5 has a certain moment of inertia and follows the rotating magnetic field of the armature winding 4 to perform stable starting rotation. And furthermore, special public service 59-3
According to the example of Publication No. 6520, the three-phase synchronization signal 9-U phase,
9-V phase, 9-W phase and output signal of comparator group 7 7-U phase,
A circuit 13 for detecting the phase difference between the 7-V phase and the 7-W phase is added, and after detecting that the phase difference between the two has become approximately zero, a switching command signal is output to the switching command means 10. 11 is switched to the output signal of comparator group 7, and these signals are input to control means 12. When rotating as a synchronous motor, the three-phase synchronous signals are 9-U phase, 9-■ phase,
9-W phase and output signal of comparator group 7 7-U phase, 7-V phase,
The phase relationship between the 7-W phases does not necessarily match, causing a phase shift. Therefore, the timing at which 01 to Q6 of semiconductor switching element group 2 are turned on and off by the three-phase synchronous signal is different from the timing at which Q1 to Q6 of semiconductor switching element group 2 are turned on and off by the three-phase output signal of comparator 7. The switching will fail and the step-out will stop.0Also, even if the step-out does not occur, an excessive current will flow through the semiconductor switching elements and damage them.To prevent this, the three-phase circuit J9' signal 9 and the comparator group If the phase difference between the three-phase output signals of No. 7 is detected and the phase difference between the two becomes approximately zero, then switching is performed, the on/off timing of Q1 to Q6 of the semiconductor switching element group 2 as described above can be obtained. There is no deviation, the switching proceeds smoothly, and stable operation of the motor 3 is enabled.

Problems to be Solved by the Invention (2) In the conventional configuration, a special circuit and its control are required to increase the circular bias, and the phase difference between the three-phase synchronization signal and the comparator group is detected. However, the problem is that the entire system becomes complicated.

The present invention solves these conventional problems and allows the motor to be started without using the above-mentioned special circuit.
It is an object of the present invention to provide a positive smoke drive device that can perform stable operation from 1 J, does not step out even when changing νJ, and suppresses excessive current to a group of semiconductor switching power supplies.

Means for Solving the Problems In order to solve the above-mentioned problems, the brushless motor drive device of the present invention uses a comparator from the time of startup to the signal of the rotating magnetic field generating means based on the signal of the synchronizing signal generating means of a certain inter-room wave number. The magnet rotor is started to rotate by increasing the power supply voltage within a certain low voltage until switching to the group signal, and the rotation is detected using the induced voltage signal, and after detection, a switching command signal is generated. It is constructed with a position detection circuit that can operate stably even if there is a phase difference between the three-phase synchronization signal and the comparator group.

Effect of the Invention With the above configuration, the power supply voltage is suppressed within a certain low voltage range until switching, so no excessive current flows, and the position of the three-phase synchronizing signal and the one output signal of the comparator group is Since the phase difference shift is below a certain level, the motor can be operated stably without step-out during switching.

EXAMPLE Hereinafter, an example of the present invention will be explained using an example of a three-phase winding with reference to the accompanying drawings.

FIG. 1 is a schematic sequence diagram of an embodiment of the present invention, FIG. 2 is an overall configuration diagram, and FIG. 3 is a semiconductor switching element group 2 based on the output signal of the comparator group 7 based on the induced voltage signal.
4 shows the phase relationship between the timing diagram of the semiconductor switching element group 2 according to the synchronizing signal during synchronous rotation and the timing diagram of the semiconductor switching element group 2 according to the output signal of the comparator group 7. .

First, explanation will be given with reference to the schematic sequence diagram in FIG. 1 and the system configuration diagram in FIG. 2. After the activation command means 14 generates a signal, the output signal of the synchronization signal generation means 8 which outputs a certain constant frequency is inputted to the rotating magnetic field generation means 9, and three-phase synchronization signals 9- of constant frequency with a phase shift of 120 degrees are inputted to the rotating magnetic field generation means 9. U phase, 9-V phase, 9-
Create W phase.

This three-phase synchronization signal is input to the switching means 11 (for example, a multi-phase synchronizer), and at startup, these signals are outputted to the control means 12, and when the respective logic levels are adjusted, the control means 12 switches the Q1 of the semiconductor switching element group 2. ~ Controls energization and cutoff of Q6. Then, the power supply 1 (for example, a switching power supply) that drives the motor 3 is increased within a certain low voltage, and a rotating magnetic field is generated in the armature winding 4 to forcibly rotate the magnet rotor.

Once the magnet rotor 5 rotates in this way, an induced voltage is generated in the armature winding 4, so after a certain period of time has elapsed, a switching command signal is generated from the switching command means 10 to switch the switching means 11. For example, the signals 7-U phase, 7-V phase, and 7-W phase signals output from the comparator group 7, which are rotor position detection signals, are output to the control means 12, and thereafter based on these logic levels. Controls Q to Q6 of the semiconductor switching element group 2 to steadily rotate the motor a.

Next, a method of creating the output signals 7-U phase, 7-V phase, and 7-W phase of the comparator group 7, which are the rotor position detection signals in one embodiment of the present invention, will be explained with reference to FIG. In Figure 3, the waveforms of the induced voltage signals at each armature winding terminal are 4-U phase,
4-V phase and 4-W phase. If we look at the U phase,
The section from 0%) to 60° and the section from 1800 to 240° are open and not connected to the power source. Also, 606
to 180°, 2400 to 30° on the e side of power supply 1.
Until 00, it is connected to the power supply 10θ sword. That is,
In this way, the amplitude of the waveform of the induced voltage signal at the armature winding terminal is maximum from 60° to 1800° and from 2400° to 360°.
By passing a current through the U phase when the current is 0, the motor t/'i can be efficiently rotated. The same applies to the other V-phase and W-phase.

Now, the induced voltage signals of each armature winding terminal 4-U phase, 4-
The V phase and the 4-W phase generate spike noise as the semiconductor switching element group 2 turns on and off, so they are removed by the signal conversion means 6. What differs from the conventional example is the time constant of the circuit of the signal conversion means 6. It simply removes spike noise within the morph drive voltage range without taking a large value, and does not shift the phase. Once upon a time, the third
As shown in the figure, [4-U phase to 6-U phase with a slightly smooth waveform]
From the 4-V phase to the 6-V phase (solid line), the 4-
The W phase is converted to the 6-W phase (solid line). Among these converted signals, for example, a signal (the 6-U phase input to the comparator group 7 in FIG. (Indicated by the dashed-dotted line in Figure 3)
The result of comparing the magnitude with that is the waveform of the 7-U phase. By comparing the magnitudes of the combined signals of the moth, a-V phase, a-W phase and 6-U phase, we synthesized 7-V phase, a-w KA, 6-U phase and 6-V phase. A 7-W phase output signal is obtained by comparing the magnitudes of the signals. Therefore, unlike the conventional example, 6-U
The point is that the output signal of the comparator group 7-U phase is created using the phase signal, the 7-V phase is created using the 6-■ phase signal, and the 7-W phase output signal is created using the 6-W phase signal. They are square waves each having a phase shift of 1200 degrees, and are input to the switching means 11 as rotor position detection signals, and are output to the control means 12 during steady rotation, and are output to the logic level (6 signals) of the three phases of each cylinder phase. mode), the semiconductor switching element group 20 is energized and energized and the magnet rotor 5 continues to rotate. In addition, as a signal to be input to the comparator group 7, a pseudo neutral point, which is indicated by the two-dot chain line in FIG. A similar output signal from the comparator group 7 can be obtained by comparing the magnitude with this signal. Among the output signals of these comparator group 7, for example, the 7-U phase signal is created based on the information of the induced voltage signals of the Even if the phase relationship with the phase is accurate and load fluctuations occur and the waveform of each phase changes accordingly,
The waveform to be compared also follows the change accordingly, resulting in a stable position detection signal. The same applies to other phases. In addition, since the time constant of the signal conversion means 6 is small and the transient characteristics are good, as can be seen from Fig. 3, it is connected to the armature winding of each phase at the point where the amplitude of the waveform of the induced voltage signal of each phase is maximum. Since the semiconductor switching element group 2 is energized, efficient and stable rotation can be achieved. Note that in order to increase the rotation speed of the magnet rotor during steady rotation, the voltage of the power source 1 may be increased.

Next, from the rotation by the synchronization signal, the switching command means 10
However, in one embodiment of the present invention, the output signal (square wave) of the comparator group 7 based on the induced voltage signal is used as the rotation detection signal. It is configured to convert these signals (clocks) and generate a switching command signal when an appropriate clock signal is exceeded by 1. Therefore, make sure that it is rotating properly before switching.

Next, at the stage of switching the signal output to the control means 12,
The reason why stable VC+fJ changes without step-out will be explained using FIG. 4. In Fig. 4, the semiconductor switching element group 2 is energized by the three-phase synchronous signal (indicated by diagonal lines in the figure) 9-U phase, 9-V phase, and 9-W phase during synchronous rotation before switching. , the control of interruption (indicated by diagonal lines in the figure) is shown from phase 9-01 to phase 9-06.

Comparator group 7 which is a position detection signal during the synchronous rotation
Normally, the output signals 7-U phase, 7-V phase, 7-W phase are in a phase lead state than the 3-phase synchronous signal 9-U phase, 9-V phase, 111.9-W phase. It is. and comparator group 7
In response to the output signal of the 7-01 phase to the 7-7
-06 phase. For example, as shown in FIG.
(Due to the relative position between the magnetization of the magnet and the armature winding), there is only one semiconductor switching element group 2 that changes no matter when a switching command is issued at any point during this synchronization. . In other words, between 0° and 60°, Q
However, if the control is based on the Domei signal, the 9-01 phase is off, and based on the output signal of the comparator group 7, the 9-03 phase is on, and the 9-03 phase is on. is on and the 7-Q3 phase is off.Then, the synchronizing signal 60
The control for switching from 120° to 120° is the same. In other words, the direction in which the magnet rotor 5 is to be rotated is the same, and it is necessary to shift the magnet rotor 5 by 600 degrees in the rotation direction and rotate the magnet rotor 5 at the moment of switching without changing this state. In other words, it is impossible for the player to become out of step. In addition, the output signals from the comparator group 7 are signals with a phase shift of 120 degrees, and these are signals that follow load fluctuations, so they can continue to rotate stably at the moment of switching and even after switching. This is possible.

Effects of the Invention As described above, the brushless morph drive device of the present invention provides the following effects.

(1) During synchronous rotation at startup, the voltage is kept within a certain low voltage range, so no overcurrent flows through the semiconductor switching elements, etc., which is effective in preventing element deterioration. (2) From startup to steady rotation There is no need for a circuit to detect the phase difference between the synchronization signal and the rotor position detection signal when switching, and the circuit can be configured smoothly from startup to steady rotation with an extremely simple circuit configuration and can be configured at low cost. The configuration of accelerating the rotor while increasing the synchronization signal is complicated because it requires a control to change the period, but according to the present invention, the same wave number of the synchronization signal can be kept constant, so it is extremely simple and the configuration can be easily achieved. It becomes a street thing.

[Brief explanation of drawings]

Fig. 1 is a schematic sequence diagram of an embodiment of the present invention, Fig. 2 is an overall configuration diagram of the same, Fig. 3 is a waveform diagram of each part of the same induced voltage signal, and Fig. 4 is a three-dimensional diagram during synchronous rotation. Phase synchronization signal and output of position detection circuit A timing chart of a semiconductor switching element, v; Figure 5 is an overall configuration diagram of a conventional example, and Figure 6 is a waveform diagram of each part of the same induced voltage signal. . G...Power supply, 2...Semiconductor switching element group, 3...Motor, 4...Armature winding, 5...Magnet rotation child, 6... signal conversion means, 7... position detection circuit (comparator group),
8... Domei signal generating means, 9... Rotating magnetic field generating means, IO... Switching command means, 11.
4: jJ conversion means, 12: control means, +4: start command means. Name of agent: Patent attorney Souo Nakao et al.
1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (2)

[Claims] (1) Connect multiple phases to an ungrounded neutral point, and connect n pieces (
An armature winding divided into 2 m poles (m is 1 or more), a group of semiconductor switching elements that conduct or cut off current to the armature winding, and a magnet rotor divided into 2m poles (m is 1 or more). a motor having a motor, a power supply for driving the motor, a start command means, a synchronization signal generation means for outputting a frequency that increases with time, and a signal outputted from the synchronization signal generation means for controlling the armature winding. a rotating magnetic field generating means for generating a rotating magnetic field; a position detection circuit for detecting the relative position of the armature winding and the magnet rotor based on a voltage signal induced in the armature winding; and the rotating magnetic field generating means. switching means for selecting, switching and outputting the output signal of the output signal and the output signal of the position detection circuit; switching command means for giving a switching command to the switching means; and switching means for controlling the switching element group using the output signal of the switching means. It consists of a control means for controlling,
During the synchronous rotation after the signal from the start command means is generated, the voltage of the power source is fixed at a certain low voltage, and the magnet rotor is started to rotate, and the switching command means is configured to detect the induced voltage signal. and a brushless motor drive device configured to switch to the output signal of the position detection circuit according to a signal from the switching command means after detecting the induced voltage signal to steadily rotate the magnet rotor. (2) The position detection circuit includes a signal conversion means for appropriately converting the signals induced in the armature windings of the plurality of phases into appropriate signals, and a virtual circuit that combines the output signals of all the plurality of phases after the signal conversion means. A comparator that compares the magnitude of the neutral point signal and arbitrary output signals of the plurality of phases, or compares the magnitude of a signal obtained by combining the output signal of a certain arbitrary phase and the output signal of other phases. Claim 1 consisting of a group
The brushless motor drive device described in Section 1.