KR20020009907A - Apparatus for controlling over current in pole change motor of compressor - Google Patents

Abstract

PURPOSE: An overcurrent control apparatus is provided to prevent a rapid temperature rise caused by the stoppage of the motor, by allowing the compressor motor to operate at a low speed even the overload protector is in operation. CONSTITUTION: An overcurrent control apparatus comprises an overload protector(10), a pole change motor(30) and a relay unit(20). The overload protector(10) operates upon detection of an overcurrent. The pole change motor(30) for compressors operates at a low or a high speed by operating in two or four poles in accordance with the operation of the overload protector. The relay unit(20) switches the coil connection in such a manner that the pole change motor for compressors operates in two or four poles in accordance with the operation of the overload protector.

Description

Apparatus for controlling over current in pole change motor of compressor}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor for a compressor, and more particularly to an overcurrent control device for a pole conversion motor for a compressor.

Generally, a compressor is a device that compresses a refrigerant by using a rotational force of an internal motor, and is used in a refrigerator, an air conditioner, and the like.

In particular, the compressor motor applied to the refrigerator is made of a stator and a rotor of two poles (N / S), as shown in Figure 1, but can vary only depending on product characteristics, but constant speed operation (for example, 3600rpm) is possible. .

On the other hand, the refrigerator operates normally when the load amount is maintained below a predetermined amount and a current of a predetermined amount or less flows, and when the current flows to the compressor motor by a load amount exceeding the predetermined amount, an overload protector (OPL) ) Is activated and operation is paused.

At this time, when the motor is operated at a fixed speed as described above, when the overload protector (OLP) is operated due to the flow of overcurrent due to the overload, the motor is paused, and such a pause of the motor causes rapid temperature rise during the stop time. It is triggered.

Nevertheless, in actual refrigerators, the compressor motor is operated at a fixed speed regardless of the temperature inside the refrigerator.

That is, as shown in FIG. 2, when an overcurrent flows due to an overload as shown in FIG. 2, an overload protector (OLP) operates to suspend power supply of the compressor motor, and thus the driving is stopped. The compressor motor is restarted with power supply due to the recovery of the overload protector (OLP).

The compressor motor according to the prior art has a problem in that the overload protector (OLP) is activated when the overcurrent flows to temporarily stop the driving of the compressor motor so that the internal temperature of the compressor rapidly rises for a predetermined time.

Accordingly, the present invention has been made to solve the above-described problems, and to provide an overcurrent control device for a pole conversion motor for a compressor to maintain a high internal temperature by allowing low-speed operation during operation of the overload protector (OLP). The purpose is.

1 is a view showing a motor for a compressor according to the prior art

Figure 2 is a graph showing the number of revolutions of the motor for the compressor during the operation of the overload protector (OLP) according to the prior art

Figure 3 is a block diagram showing an overcurrent control device of a pole conversion motor for a compressor according to the present invention

4 is a view showing a pole conversion motor for a compressor according to the present invention

5 is a circuit diagram showing a detailed configuration of the two-pole driving of the pole conversion motor for a compressor according to the present invention

6 is a circuit diagram showing a detailed configuration of the four-pole driving of the pole conversion motor for a compressor according to the present invention

7 is a graph showing the rotational speed of the pole conversion motor for the compressor during the operation of the overcurrent protector (OLP) according to the present invention

＊ Description of symbols for main parts of the drawings ＊

10: Over Load Protector 20: Relay

30: pole change motor M1 to M4 for compressor: main winding

S1 to S4: auxiliary winding MC1, MC2: main compensation winding

SC1, SC2: auxiliary compensation winding RY1, RY2: first and second relay

The overcurrent control device of the pole conversion motor for a compressor according to the present invention operates by two or four poles according to the operation of the overload protector (OLP) and the operation of the overload protector (OLP) according to the overcurrent detection Compressor pole conversion motor for high speed or low speed operation, and the relay unit for switching the winding connection state so that the compressor pole conversion motor to operate in two or four poles depending on the operation of the overload protector.

Hereinafter, with reference to the accompanying drawings, a preferred embodiment of the overcurrent control apparatus for a pole conversion motor for a compressor according to the present invention will be described in detail.

3 is a block diagram showing an overcurrent control apparatus of a pole conversion motor for a compressor according to the present invention, Figure 4 is a view showing a pole conversion motor for a compressor according to the present invention, Figure 5 is a pole conversion motor for a compressor according to the present invention 6 is a circuit diagram showing a detailed configuration when driving a two-pole, Figure 6 is a circuit diagram showing a detailed configuration when driving a four-pole of the compressor pole conversion motor, Figure 7 is a view showing the rotational speed of the pole conversion motor for the compressor when the overcurrent protector (OLP) operation to be.

As shown in FIG. 3, an overcurrent control apparatus for a pole conversion motor for a compressor according to the present invention includes an overload protector (OLP) 10 operating according to whether an overcurrent is detected, and the overload protector (OLP) 10. The pole conversion motor 30 for the compressor for high speed or low speed operation by operating in two or four poles depending on the operation, and the pole conversion motor 30 for the compressor according to the operation of the overload protector 10 It is configured to include a relay unit 20 for switching the winding connection state to operate as a pole or four poles.

As shown in FIG. 4, the compressor pole converting motor 30 according to the present invention includes a rotor and a stator for performing a high speed / low speed operation of the motor through a pole change (2 poles / 4 poles). It is configured to include.

In addition, the stator of the configuration of the pole conversion motor 30 for a compressor according to the present invention will be described in more detail, as shown in Figure 5, to generate a starting torque of the rotor (not shown) by operating in two or four poles First to fourth auxiliary windings M1 to M4 and first to fourth auxiliary windings for maintaining rotation of the rotor after the initial starting of the rotor by the first to fourth main windings M1 to M4. (S1 to S4), the first and second main compensation windings MC1 and MC2 for compensating for magnetic field abnormalities due to the same polarity in the first to fourth main windings M1 to M4 during two-pole operation, The first and second auxiliary windings S1 to S4 may be configured to include first and second auxiliary compensation windings SC1 and SC2 to compensate for magnetic field abnormalities due to the same polarity.

The first to fourth main windings M1 to M4 and the first to fourth auxiliary windings S1 to S4 are operated according to whether the overload protector OLP is operated according to the overcurrent flow of the pole conversion motor for the compressor. The relay unit 12 for converting the polarity into two or four poles and switching the connection state of the first and second main compensation windings MC1 and MC2 and the first and second auxiliary compensation windings SC1 and SC2 is provided. It is composed of linkage.

In this case, the relay unit 12 connects the first and second main compensation windings MC1 and MC2 between the first and fourth main windings M1 and M4 and the second and third main windings M2 and M3. At the same time, the first to fourth main windings M1 to M4 are converted to two poles, or the first and fourth main windings MC1 and MC2 are disconnected from each other. The first relay RY1 for converting the first to fourth main windings M1 to M4 into four poles while connecting the windings M1 and M4 and the second and third main windings M2 and M3 in series. ) And the first and second auxiliary compensation windings SC1 and SC2 between the first and fourth auxiliary windings S1 and S4 and the second and third auxiliary windings S2 and S3. The first to fourth auxiliary windings S1 to S4 are converted into two poles, or the first and fourth auxiliary windings S1 and SC2 are disconnected from each other so that the first and fourth auxiliary windings S1 are disconnected. , S4) and the second and third auxiliary windings (S2, S3) in series and the first If the fourth consists of the second relay (RY2) for the secondary winding (S1 ~ S4) to convert the 4-pole.

And the first to fourth main windings M1 to M4, the first to fourth auxiliary windings S1 to S4, the first and second main compensation windings MC1 and MC2, and the first and second auxiliary compensation windings ( Looking at the form of SC1, SC2, as shown in Figure 5, the first main compensation winding (MC1) is located between the first main winding (M1) and the second main winding (M2) and the third main winding (M3) and the first The second main compensation winding MC2 is located between the four main windings M4, and the first auxiliary compensation winding SC1 is positioned between the first auxiliary winding S1 and the second auxiliary winding S2, and the third auxiliary winding The second auxiliary compensation winding SC2 is positioned between the winding S3 and the fourth auxiliary winding S4.

Referring to the operation of the overcurrent control device of the pole conversion motor for a compressor according to the present invention configured as described above are as follows.

First, when the load of the device is kept below a predetermined amount, for example, in a refrigerator, and a current of a predetermined amount or less flows through the pole conversion motor for a compressor, it is required to operate with two poles.

In this case, the relay unit 20 is designed to have a circuit connection configuration in which all the contacts are 'on' so that the motor can operate in two poles when the load is maintained below a certain amount by operating in conjunction with the overload protector (OLP) 10. In addition, when the overcurrent is detected as the load increases, the overload protector (OLP) 10 is designed to have a circuit connection configuration in which all the contacts are 'off' so that the motor can operate with four poles.

Accordingly, as shown in FIG. 5, all the contacts of the relay unit 20 are switched to an 'on' state, and thus the first and fourth main windings M1 and M4 and the second and third main windings M2 and M3 are thus switched. First and second main compensation windings MC1 and MC2 are connected in series, and between the first and fourth auxiliary windings S1 and S4 and the second and third auxiliary windings S2 and S3. 2 The auxiliary compensation windings SC1 and SC2 are connected in series.

In addition, current flows from the power supply to each of the windings to have the polarity of 'NNS-S' in the order of the first to fourth main windings M1 to M4, that is, 'M1-M2-M3-M4', and the auxiliary winding S1. S4) also has the same polarity as the main winding in the order of the first to fourth auxiliary windings, so that the motor becomes two poles in the form of a winding.

In addition, the first main compensation winding MC1 has an 'N pole' having the same polarity as the first main winding M1 and the second main winding M2, and the second main compensation winding MC2 has a third main winding ( It has the same polarity as M3) and the fourth main winding M4, 'S pole', and the first and second auxiliary compensation windings SC1 and SC2 also have the same polarity as the auxiliary windings on both sides.

Subsequently, rotation of the rotor is started by the starting torque of the first to fourth main windings M1 to M4 generated by receiving power, and the motor is moved to two poles by the first to fourth auxiliary windings S1 to S4. It is driven at high speed.

Therefore, an external speed sensor (not shown) detects a predetermined number of revolutions (for example, 3600 rpm) and maintains the speed by repeatedly turning the motor on and off.

In this case, when the motor is operated in two poles, the windings adjacent to each other among the first to fourth main windings M1 to M4 and the first to fourth auxiliary windings S1 to S4 have the same polarity. Since the main winding M1 and the second main winding M2 have an 'N pole', an abnormality in the space magnetic flux distribution to generate a 'S pole' is forcibly generated in the space therebetween. ) Has an 'N pole' to cancel the 'S pole' component to compensate for the abnormality of the spatial flux distribution. In addition, the second main compensation winding (MC2) and the first and second auxiliary compensation winding (SC1, SC2) also performs the same compensation operation as above to play a role of improving the operation performance of the pole conversion motor.

On the other hand, for example, when the load of the refrigerator increases and an overcurrent flows in the pole converting motor for the compressor, a bimetal overload protector (OLP) is operated to maintain the flowing overcurrent at a current less than a predetermined amount. Therefore, as shown in FIG. 6, the pole conversion motor for the compressor must be operated by four poles.

Therefore, as shown in FIG. 6, all of the contacts of the relay unit 20 are switched to an 'off' state, so that the first and fourth main windings M1 and M4 and the second and third main windings M2 and M3 are connected. The first and fourth auxiliary windings S1 and S4 and the second and third auxiliary windings S2 and S3 are connected in series, and the first and second main compensation windings MC1 and MC2 and the auxiliary compensation winding ( SC1 and SC2 are disconnected.

In the first and fourth main windings M1 and M4, current flows in the same direction as in the two-pole operation, and maintains the same polarity. However, in the second and third main windings M2 and M3, the flow of current is reversed. Therefore, the polarity is also reversed so that the first to fourth main windings M1 to M4 have the polarity of 'NSN-S' in the order of 'M1-M2-M3-M4' and the first to fourth auxiliary windings ( S1 ~ S4) Also, the winding has the same polarity as the main winding in the order of winding, and the motor becomes four poles in the form of winding.

Subsequently, the rotation of the rotor is started by the starting torque of the first to fourth main windings M1 to M4 supplied with power, and the motor is driven at low speed by four poles by the first to fourth auxiliary windings S1 to S4. do.

Therefore, an external speed sensor (not shown) detects a predetermined number of revolutions (for example, 1800 rpm) and repeats the on / off of the motor to maintain the speed.

In this case, when the motor is operated with four poles, the first to fourth main windings M1 to M4 and the auxiliary windings S1 to S4 are adjacent to each other and have opposite polarities. MC1 and MC2 and the auxiliary compensation windings SC1 and SC2 are unnecessary. For example, since the first main winding M1 has the 'N pole' and the second main winding M2 has the 'S pole', there is no abnormality in the space magnetic flux distribution in the space therebetween and therefore the first main winding. The compensation winding MC1 is not necessary, and the second main compensation winding MC2 and the first and second auxiliary compensation windings SC1 and SC2 are also unnecessary for the reason described above.

Therefore, when the motor is operated with four poles, the connection state between the first and second main compensation windings MC1 and MC2 and the first and second auxiliary compensation windings SC1 and SC2 is released.

Then, when the overload exhalation unit (OLP) is normally restored, the pole conversion motor for the compressor is converted to two poles to operate.

As a result, in the present invention, as shown in FIG. 7, when a load of a predetermined amount or less is applied and a current flows below a predetermined amount, the motor is operated at a high speed of two poles, and the load is increased by a certain amount or more, that is, an overcurrent flows, thereby causing an overload protector (OLP). Is operated to operate the motor at a four-pole low speed to prevent rapid temperature rise due to motor stop.

The overcurrent control device of the pole conversion motor for a compressor according to the present invention can expect the following effects.

First, the current flow can be reduced by a predetermined amount due to the low speed operation by the polar conversion.

Second, since the low-speed operation is possible during the operation of the overload protector (OLP) due to the flow of overcurrent, it is possible to prevent the rapid temperature rise due to the motor stop.

Claims (3)

An overload protector (OLP) operating according to whether an overcurrent is detected; A pole conversion motor for a compressor for high speed or low speed operation by operating in two or four poles according to the operation of the overload protector (OLP); and And a relay unit for switching a winding connection state so that the compressor pole conversion motor operates in two or four poles according to the operation of the overload protector. According to claim 1, The compressor pole converting motor operates as a two pole when the overcurrent protector (OLP) does not operate, and operates as a four pole when the overcurrent protector (OLP) operates. . According to claim 1, When the overload protector is not operated, all the contacts of the relay unit are switched on so that the compressor pole conversion motor operates as two poles, and when the overload protector is operated, the pole conversion motor for the compressor is operated as four poles. The overcurrent control device of the pole conversion motor for a compressor, characterized in that all the contacts of the relay unit 'off' switching.