JPS60152291A - Condenser motor - Google Patents

Abstract

PURPOSE:To prevent a reverse electromagnetic torque from occurring due to the interruption of a condenser motor by connecting a resistor with both ends of the capacitor during the interruption of a power source, thereby reducing the winding remaining current. CONSTITUTION:A resistor rdc is connected in series through a bidirectional thyristor SW2 at both ends of a condenser motor C. The thyristor SW2 becomes ON during the interruption of the power source, a resistor is connected with both ends of the capacitor, and a current Ir is flowed to the resistor. Accordingly, the energy stored in the capacitor is heat-dissipated by a self-exciting phenomenon, and the winding remaining currents IM, IA at the power source interruption time can be abruptly attenuated. Then, even if the power source is again energized, no remaining current exists in the winding. Thus, the winding current does not increase at the energizing moment, and the reverse electromagnetic torque can be therefore prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a capacitor motor, and particularly to a stator winding circuit suitable for intermittent operation.

[Background of the invention]

As shown in Figure 1, the winding circuit of a capacitor run motor, in which the capacitor is connected to the winding even during rated operation of the capacitor motor, has a spatial phase difference between the stator winding and the main winding M. A capacitor C is connected in series with the auxiliary winding A and the auxiliary winding. In addition, the rotor is generally a cage-saiga trochanter R.

Contin Saran motors are widely used as motors that drive fans, pumps, etc., and the power is interrupted for a short time (15ec8 degrees) as shown in Figure 2 (t).

~1+), when the power is turned on again, 1. , an electromagnetic torque TR opposite to the rotational direction w is abnormally generated. There was a drawback in that the design had to have a larger shaft bearing capacity than necessary.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a capacitor run motor in which reverse torque generated by intermittent operation is small.

[Summary of the invention]

The cause of reverse torque during intermittent operation of a capacitor run motor is the main line circuit currents IN and I when the power supply is interrupted.
It turns out that this is because A remains indefinitely due to the self-excitation phenomenon caused by the capacitor, and this residual current causes the winding current to rise at the moment the power is turned on again.

Therefore, in the present invention, as a method of quickly attenuating the winding current when the power supply is interrupted, a resistor is connected to the capacitor only during the interruption period, and the capacitor energy is released.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 3 and 4. The configuration of the winding circuit of the capacitor run motor of the present invention is as shown in FIG. are connected in series through a switch SW2, here a bidirectional thyristor. Also, thyristor game) GK is powered on.

An element 1 for detecting OFF, a power supply (JN-OFF inverting circuit 2, a gate 1g generation circuit 3, and a gate power supply 4 are connected to each other.The operation of the switch SW2 is as shown in FIG. 4. According to this configuration circuit, the gate signal of the thyristor constituting SW2 is set to be OFF when the power is ON and ON when the power is OFF. During the power interruption period (to~1+), a resistor is connected across the capacitor,
Since the current 1 bypasses and flows through this resistor, the energy accumulated in the capacitor due to the self-excitation phenomenon is dissipated by the resistor, and the winding residual current I when the power supply is interrupted.
M, IA can be rapidly attenuated. Thereafter, even when the power is turned on again, since there is no residual current in the winding, there is no increase in the winding current at the instant of turning on, and therefore, there is an effect that generation of reverse electromagnetic torque can be prevented.

In another embodiment, as shown in FIG. 5, the switch SW2 is replaced with a B-contact contactor that turns on the switch SW2 when the power is turned off. In this case, the circuit configuration becomes simple.

It goes without saying that the same effect can be obtained even if the resistor rde is not connected in parallel with the capacitor as shown by the broken line in FIG. 5, but is also connected in parallel with the auxiliary winding.

Furthermore, as another embodiment, FIG.
It is something. Switch SW3 is connected to ■ at startup, and disconnected when the speed approaches the rated speed, switch 8W3 is connected to @, and resistor rd is connected in parallel with capacitor C.
o is connected. Conventionally, a resistor is not connected to a disconnected capacitor, so the charge remains, and when the power is interrupted and restarted, a reverse electromagnetic torque similar to the capacitor run motor mentioned above is generated. However, the present invention solves this problem.

〔Effect of the invention〕

According to the present invention, it is possible to reduce the residual current in the winding when the 'FJE source is interrupted, which is the cause, and therefore it is possible to prevent reverse electromagnetic torque due to intermittent operation of the capacitor run motor.

[Brief explanation of the drawing]

Figure 1 is a winding circuit diagram of a conventional capacitor run motor, Figure 2 is a waveform diagram of the winding current and torque when the capacitor run motor is operated intermittently, and Figure 3 is an example of a misfire. FIG. 4 is a winding current waveform diagram during intermittent operation, and FIGS. 5 and 6 are configuration diagrams showing other embodiments of the present invention. M...Main winding, A...Auxiliary winding, C...Capacitor, rd. ···resistance. , /de＼, Figure l Figure 2 Figure 3 Figure 4 Figure S Figure 6 w3

Claims (1)

[Claims] (1) In a stator winding circuit including a main winding, an auxiliary winding disposed with a spatial phase difference from the main winding, and a capacitor provided in series with the auxiliary winding, during operation. A capacitor motor characterized in that a resistor is connected in parallel with the capacitor only during periods when the power supply is interrupted. 2. Scope of claims! < The capacitor motor according to item 1, characterized in that the stator winding circuit is disconnected from the power supply during operation, and a resistor is connected in parallel with the capacitor only during the period when the capacitor is disconnected.