JPH08322283A - Inverter controller of permanent magnet type synchronous motor - Google Patents

Abstract

PURPOSE: To obtain the normal operation of a three-phase synchronous motor even if the synchronous motor is connected to an inverter without making the respective phase orders of the motor and the inverter agree with each other by a method wherein currents are distributed among the armature windings of the synchronous motor in accordance with signals which are generated by an induced voltage detecting means and a phase order pattern judging means. CONSTITUTION: An inverter 2 and a synchronous motor 3 are connected to each other without confirming the respective phase orders. After the inverter 2 and the synchronous motor 3 are connected to each other, the shaft of the synchronous motor 3 is turned in a forward direction. As the rotor of the synchronous motor is composed of permanent magnets, voltages are induced in armature windings. The phases of the induced voltages are detected by a phase detector 6. The signals from the phase detector 6 are processed by a computer 7 to predetermine the phase order. Once the phase order is predetermined, the phase order is stored in the nonvolatile memory, so that the phase order predetermining operation becomes unnecessary. With this constitution, the man-hours of the work for making the respective phases with each other can be saved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inverter control device for a synchronous motor in which a rotor is a permanent magnet, and in particular, an inverter control which does not require phase matching of three phases when connecting the synchronous motor and the inverter. Regarding the device.

[0002]

2. Description of the Related Art In recent years, electric motors used in precision machine tools and compressors are required to rotate at high speeds of 100,000 rpm or more, and ultra-high speed synchronous electric motors using a permanent magnet as a rotor have been developed. An ultra-high speed synchronous motor using such a rotor as a permanent magnet has an armature winding on the stator, detects the direction of the magnetic flux generated by the permanent magnet, and passes the armature current in the direction orthogonal to the direction of the magnetic flux. Generates torque.

In the above synchronous motor, it is necessary to synchronize the excitation order of the windings of the stator coil and the phase of the magnetic poles of the permanent magnet rotor. Three-phase AC is usually expressed as U-phase, V-phase, and W-phase, but in a three-phase synchronous motor, stator coils of each phase are arranged in the armature in the order of the phases, and the three-phase AC power supply is connected in accordance with the phase order. To be done. If the U-phase, V-phase and W-phase of the inverter device (three-phase AC power supply) do not match the U-phase, V-phase and W-phase of the synchronous motor, the motor cannot be operated.

[0004]

In the above synchronous motor, the inverter device cannot be operated unless the U-phase, V-phase and W-phase of the inverter are matched with the U-phase, V-phase and W-phase of the synchronous motor. However, there is a problem that the number of work steps increases because the phases are matched when the synchronous motor is installed. The present invention is intended to improve such a conventional problem, and an object thereof is to achieve the above-mentioned synchronous motor even if the connection between the inverter device and the three-phase synchronous motor is performed without making the phase sequence match. It is to provide an inverter device that can operate normally.

[0005]

To achieve the above object, according to the present invention, in an inverter control device for a permanent magnet type synchronous motor, induction is induced in an armature winding on the stator side as the rotor rotates. Generated by the induced voltage detecting means, the means for measuring the timing of the three-phase signal by the signal detected by the induced voltage and determining the phase sequence pattern, the induced voltage detecting means and the phase sequence pattern determining means. And a distribution control means for distributing current to the armature winding of the synchronous motor according to the signal.

[0006]

With the above-described structure, the synchronous motor can be operated normally even if the inverter device and the three-phase synchronous motor are connected arbitrarily without the phase order being matched. Since the phases are matched when the electric motor is installed, there is an effect that the number of work steps can be reduced.

[0007]

Next, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a configuration block diagram showing an embodiment of a synchronous motor using a rotor as a permanent magnet and an inverter control device thereof according to the present invention. In the figure, reference numeral 1 is a power source, which is a DC power source such as a battery or a commercial AC power source rectified in this figure. 2 is an inverter and the DC power source 1
Is a power switching circuit for generating a three-phase alternating current from. Reference numeral 3 denotes a synchronous motor in which the rotor is made of a permanent magnet and the stator has an armature winding. Reference numeral 4 is a drive circuit of the inverter 2, 5 is a control circuit thereof, and 6 is a phase detection circuit of the synchronous motor 3. Reference numeral 7 is a computer that controls the control circuit 5 and the phase detection circuit 6, and is exemplified by a one-chip microcomputer in this embodiment. Of course, the computer 7
Is not limited to a one-chip computer, but may be selected according to various needs of the device of the present invention. The computer 7 has a CPU, I as shown.
/ O and memory.

Now, an outline of the operation of this embodiment will be described with reference to FIG. In the present embodiment, the connection between the inverter 2 and the synchronous motor 3 is arbitrarily connected without checking the phase sequence. Therefore, some kind of phase sequence setting operation is necessary, but in the present embodiment, after connecting the inverter 2 and the synchronous motor 3 to each other, the shaft of the synchronous motor 3 is normally rotated by means such as manual operation. Thereby, since the rotor of the synchronous motor 3 is a permanent magnet, an induced voltage is generated in the armature winding. The phase sequence is set by detecting the phase of the induced voltage by the phase detector 6 and calculating the signal by the computer 7. Once the phase sequence is set, the phase sequence is stored in the non-volatile memory of the computer 7, and the above-described phase sequence setting operation is not necessary.

The induced voltage of the synchronous motor 3 during the phase sequence setting operation and the phase sequence setting method therefor will be described with reference to FIG. When the inverter 2 and the synchronous motor 3 are arbitrarily connected, the phase of the induced voltage generated by positively rotating the synchronous motor 3 has two patterns as shown in FIG. That is, when an arbitrary phase C is observed as a reference, as shown in FIG. 2A, a case where a phase A that rises with a delay of 120 degrees and a phase B that rises with a delay of 240 degrees relative to the rise of the reference phase C are connected , As shown in FIG. 2 (b),
There are two patterns, that is, the case where the B phase which rises 120 degrees behind the rise of the reference phase C and the case where the A phase which rises 240 degrees behind are connected. The present invention detects the difference between the phases of any one phase connected from these phenomena and the phases of the other two phases, and sets the phase sequence.

By the way, in the case of FIG. 2A, C is U
When the phase is set, A and B are set to the V phase and the W phase, respectively. In the case of (b), when C is set to the U phase, A and B are set to the W phase and the U phase, respectively. Here, the phase sequence of FIG. 2A is “phase sequence 1”, and the phase sequence of FIG. 2B is “phase sequence 2”.
Tentatively defined and used in the description below.

3 and 4 show a flow of the phase sequence setting operation executed by the computer 7. FIG. 3 is a main flowchart. When the power is turned on, the computer 7 is activated and this flow is also executed (S1). Next, various initial values are set in S2, and it is determined in S3 whether or not the phase sequence has already been set. Here, if the phase sequence has already been set, the following phase sequence setting means is not executed, and the main control (S6) of the synchronous motor 3 is executed. By the way, whether or not the phase sequence is set is set by setting a set flag in the non-volatile memory of the computer 7 and checking it. If it is determined in S3 that the phase has not been set, the process proceeds to S4, in which it is determined whether the synchronous motor 3 is rotating. If the synchronous motor 3 is not rotating, it does not proceed to the next step until it is rotated. Therefore, even if the power is turned on, the synchronous motor 3 is not operated while the phase sequence remains different. The determination of the rotation of the synchronous motor 3 is made based on the induced voltage generated by the rotation of the armature winding. When it is determined in S4 that the synchronous motor 3 has rotated, S5
Phase setting routine is executed, and when it is completed, S6
The main control of the synchronous motor 3 is executed. Here, in the case of a setting operation by manual rotation, the synchronous motor 3 suddenly starts to rotate, which is dangerous. Therefore, when S5 is completed, the completion of the phase sequence setting is displayed by an indicator lamp or voice, and the power is turned on again to turn the synchronous motor 3 on. It is also possible to allow driving.

The phase setting routine shown in FIG.
Described in. First, in the phase setting routine, S7 and S8
2 reads Ta and Tb in FIG. 2, that is, the phase difference between any two phases and the other two phases. Specifically, Ta and Tb measured by a known method using a timer and a counter
Is read. Next, in S9, the magnitudes of Ta and Tb are compared, and if Ta <Tb, the phase order 1 in FIG. 2 is set, and if Ta> Tb, the phase order 2 in FIG. 2 is set. At the same time, the flag for which the phase sequence has been set is written in the non-volatile memory of the computer 7. After these are executed, the process returns to the main flow (S12).

Although the present invention has been described with reference to the above embodiments, various modifications and applications are possible within the scope of the gist of the present invention, and these modifications and applications are not excluded from the scope of the present invention. Absent.

[0014]

As described above, since the inverter device and the three-phase synchronous motor are connected as described above, the synchronous motor can be normally operated even if any connection is made without matching the phase sequence. Moreover, there is an advantage that the number of work steps can be reduced because the phases are matched when the synchronous motor is installed. Further, in the past, when the phase sequence was incorrectly connected, the inverter element was damaged, but the present invention can prevent this. Furthermore, since the electric motor can be operated for the first time by turning the power on again after setting the phase sequence, the electric motor does not suddenly rotate when the power is turned on, so the safety of the electric motor installation work can be improved.

[Brief description of drawings]

FIG. 1 is a configuration block diagram showing an embodiment of the present invention.

FIG. 2 is a diagram showing a concept of phase sequence setting of the present invention.

FIG. 3 is a phase sequence setting flow according to an embodiment of the present invention.

FIG. 4 is a phase setting routine according to an embodiment of the present invention.

[Explanation of symbols]

 1 ... Power supply 2 ... Inverter 3 ... Synchronous motor 4 ... Drive circuit 5 ... Control circuit 6 ... Phase detection circuit 7 ... Computer

Claims (1)

[Claims] 1. An inverter control device for a permanent magnet type synchronous motor, wherein the control device detects induced voltage by means of induced voltage detecting means induced in an armature winding on the stator side as the rotor rotates. Means for measuring the timing of the three-phase signal by the generated signal and determining the phase sequence pattern, and the armature winding of the synchronous motor in accordance with the signals generated by the induced voltage detection means and the phase sequence pattern determination means. An inverter control device for a permanent magnet type synchronous motor, comprising: a distribution control means for distributing a current to a wire.