JPS6216797Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a control device for increasing the reliability of a commutatorless motor that controls forward and reverse rotation.

As is well known, the direction of rotation of a commutatorless motor is detected by detecting the phase rotation of the output signal of a distributor. Normally, the output signal of this rotation direction detector is used to switch the polarity of the F/V converter that generates the feedback signal for the speed control loop of the non-commutated motor, to select the distributor to be used, and to send alarms to the outside. are doing.

Therefore, if the rotational direction detector malfunctions, problems such as runaway of the commutatorless motor and excessive or insufficient generated torque may occur. In addition, for example, in a centrifugal separator for sugar production, excessive speed during reversal has a very high risk of causing damage to the machine.

Figure 1 shows two conventional rotation direction detectors.
FIG. 2 is a diagram showing a control system of a commutatorless motor having two distributors. In Figure 1, 1 is an AC power supply, 2
3 is a cycloconverter, 4 is a non-commutator motor, 5 and 6 are distributors, and 7 is a non-commutator motor 4 by detecting the phase rotation of the output signal of the distributor 5. 8 is an F/V converter that detects the number of pulses of the distributor 5 and generates an analog signal proportional to the speed of the non-commutated motor 4; 9 is a rotation direction detector 7; 10 is a control device for operating the cycloconverter 3; and 10 is a control device for operating the cycloconverter 3.

The rotation direction detector 7 detects the phase rotation of the output signal 5a of the distributor 5, and switches the potential of the output signal 7a between a high potential and a low potential by rotating the commutatorless motor 4 forward and reverse. An F/V converter 8 generates a speed feedback signal by operating a polarity switching circuit 9 based on the output signal 7a of the rotation direction detector 7.
The polarity of the output signal is switched. Also, the control device 1
0 selects whether to use the output signal 5a of the distributor 5 or the output signal 6a of the distributor 6.

In the control device for a non-commutated motor configured as described above, if the rotation direction detector 7 fails or malfunctions, the output of the F/V converter 8 will not be switched, and the non-commutated motor 4 will run out of control. It was hot.

The present invention has been made in view of the above-mentioned points, and in contrast to the conventional method in which the rotation direction was detected using the output signal of one distributor, the present invention detects the rotation direction using the output signal of one distributor. A separate rotation direction detector is installed using the output signal of the rotation direction detector, and even if one rotation direction detector fails, a discrepancy in the output signals of multiple rotation direction detectors is detected and the operation of the non-commutated motor is stopped. The present invention provides a control device for a commutatorless motor configured to

The present invention will be explained below based on the drawings of the embodiments. FIG. 2 is a control system diagram showing an embodiment of the present invention, in which a rotation direction detector is also provided on the output signal side of the distributor 6 for backup when the rotation direction detector 7 fails. It is. Reference numerals 1 to 10 in FIG. 2 are the same as those in FIG. 1, respectively. Reference numeral 11 indicates a rotational direction detector that receives the output signal 6a of the distributor 6, and 12 indicates an output signal 7 of the rotational direction detector 7 and the rotational direction detector 11.
a mismatch detection circuit that detects mismatch between a and 11a;
13 is a time delay circuit, and 14 is a current throttle command circuit.

In FIG. 2, the rotational direction detector 7 used conventionally has failed and the output signal 7a is replaced by the output signal 11 of the rotational direction detector 11 added according to the present invention.
When a mismatch occurs, the mismatch detection circuit 12 operates, and after a time delay determined by the setting value of the time delay circuit 13, the mismatch signal 13a is sent to the current throttle command circuit 14. The output signal 14a of this current throttle command circuit 14 is input to a control device 10 for operating the thyristor converter 3. This output signal 1
4a, for example, by narrowing down the gate firing phase angle of the thyristor of the cycloconverter 3, or by cutting off the gate signal, the commutatorless motor 4
It is configured so that it can be stopped.

Although not shown, if the power of the mismatch signal 13a of the output of the time delay circuit 13 is amplified by an auxiliary relay, the excitation of the switch 2 is cut off, and the switch 2 is released, the cycloconverter 3 is switched to the AC power source 1. It can also be separated from.

In the above description of the present invention, the rotation direction detector is
In this case, the rotation direction detector is 3
Needless to say, the same holds true even in the case of more than one.

As described above, according to the present invention, even if one rotational direction detector fails, since multiple rotational direction detectors are used, a discrepancy in the output signals is detected and the non-commutated motor can be activated. It can be stopped safely and the reliability of control when performing forward and reverse rotation can be improved.

[Brief explanation of the drawing]

FIG. 1 is a control system diagram showing a conventional control device for a non-commutated motor, and FIG. 2 is a control system diagram showing an embodiment of the present invention. 1... AC power supply, 2... Switch, 3... Cycloconverter, 4... Commutatorless motor, 5, 6...
...Distributor, 7, 11...Rotation direction detector, 8...
F/V converter, 9... Polarity switching circuit, 10... Control device, 12... Mismatch detection circuit, 13... Time delay circuit, 14... Current throttle command circuit.

Claims (1)

[Scope of utility model registration request] At least two or more sets of rotation direction detectors are provided with a plurality of distributors, and detect the rotation direction of the commutatorless motor by detecting the phase rotation of the output signal of the distributor. The motor is installed on the output signal side and enables forward and reverse rotation by switching the polarity of the output signal of the F/V converter between forward and reverse using the signal from one rotation direction detector. The control device for a commutator motor is configured to stop the operation of the commutatorless motor via a time delay circuit having a predetermined delay function when the output signals of the rotation direction detectors do not match. A control device for a commutatorless motor, characterized in that: