KR101134515B1 - Ac mortor starting by capacitor - Google Patents

Abstract

PURPOSE: A starting condenser-shaped ac motor for high starting torque is provided to enable the generation of starting torque in initial starting by the installation of a starting condenser and a starting relay. CONSTITUTION: A triac(D1) is serially connected to a starting wire(W3). The triac is switched into one and off by the control of CPU. The first and second comparators(U1,U2) sense the voltage of both ends of the starting wire and the triac, respectively. A phase difference detecting unit detects the phase difference between voltage and current from power source applied to the starting wire by receiving the voltage. The CPU calculates the rotation speed of a motor rotor from the phase difference. Control signals are applied to a gate terminal of the triac through a driver(TD) according to calculation result.

Description

AC Mortor starting by capacitor

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a starting condenser-type AC motor which supplies a sufficient amount of starting torque required for initial starting by supplying a magnetic flux of a rotating magnetic field, which is insufficient at initial starting, and is a commercial power source. It requires high high starting torque during initial start-up, such as food grinder, and is suitable for requiring high operating torque even during operation. More specifically, it has high compatibility with load and power fluctuations, It protects windings, and the start relay is a starter condenser type AC motor that uses a triac and has a semi-permanent life without electric arc. Furthermore, it is inexpensive to manufacture, efficient for small start and stop, strong against electric noise, and start relay. Condenser AC motor suitable for high starting torque for easy installation Relate to.

In general, since a single-phase AC motor has an alternating magnetic field, the starting torque becomes zero at initial startup, and thus requires a device for initial startup.

Thus, the single-phase AC motor starts as a two-phase induction motor at start-up using a start winding for initial start-up, and separates the start winding from the main winding when the start is completed.

At this time, a starting capacitor is provided to supply starting power to the starting winding, and a starting switch is provided to supply or cut off the starting power to the starting winding. That is, the start winding, the start capacitor, and the start switch are devices for initial start of the single-phase AC motor.

In the past, mechanical switches that were turned on and off by the rotational speed of the motor rotor (that is, centrifugal force) were mainly used as starting switches. However, since centrifugal force switches are turned on and off at high voltage, sparks are generated in the switch, and repeated on, In recent years, electronic switches using semiconductor devices are mainly used due to a problem in that reliability is lowered due to wear due to an off operation.

Starting capacitors using commercial AC power as a driving power source are also important for the stability and reliability of initial start-up.However, stable drive power is provided to cope with unstable fluctuations in commercial AC power or motor load during motor operation. It is also important to protect the motor, including the drive circuit.

In particular, a high starting torque may be formed in a grinder or a processor such as food or waste, so that initial starting may be performed, and a high starting torque may be formed even during operation to enable smooth grinding or processing of food or garbage.

However, AC motors, which are conventionally used for crushing or treating food or garbage, use a mechanical start relay as a start switch, and are turned on and off at a high voltage during start, so sparks are generated at a switch (ie, a mechanical start relay). And, there is a problem that the reliability is lowered due to wear, etc. due to repeated on, off operation.

Therefore, in the device that requires high starting torque during initial start-up, such as a crusher or a processing machine such as food or waste, and uses a high starting torque during the operation, the electronic starting relay is used to improve the starting of the motor, There is a need to increase the efficiency of the treatment.

The present invention provides a high starting power supply having a driving capacitor for supplying a driving power to continuously generate a stable magnetic field in response to sudden power failure, unstable fluctuation of a commercial AC power supply such as overshoot, or load fluctuation during operation of a motor. It is an object to supply a starting condenser type AC motor suitable for torque.

In addition, a highly reliable electronic switch is used as a start switch for supplying or cutting start power to the start winding, and using triac as a switching element, there is no electric arc generation and a semi-permanent life, and for triac switching control The detection of the rotational speed of the motor rotor is detected by comparing the phase difference between the voltage and the current, which improves the accuracy of the rotational speed detection and the switching control, and thus the high starting torque which has an excellent effect on the protection of the starting capacitor and the starting winding. It is an object to supply a suitable starting condenser type AC motor.

The ground wire is removed to remove electrical noise, and the ground wire is easily connected to the cover through the fixing bolt, the starting relay is built into the case, and the case with the starting relay molded by synthetic resin such as epoxy or silicone The object of the present invention is to provide a starting condenser type AC motor suitable for high starting torque, which is protected from dust, impact, and the like, and has a through hole through which a fastening bolt is inserted into the case and is easily mounted on a motor inner box or an enclosure.

In addition, a mechanical component such as a stator, a rotor, a cover, etc. aims to provide a starting condenser-type AC motor suitable for high starting torque with high economic efficiency by simplifying and miniaturizing the structure and simplifying assembly and assembly, thereby reducing manufacturing costs.

In addition, through various advantages as described above, it is an object of the present invention to improve starting to be suitable for crushing or treating food or garbage, and to form a high starting torque and a high operating torque to provide a high efficiency starter condenser AC motor.

Starting condenser AC motor suitable for high starting torque according to the present invention for achieving the above object is

Two main windings for generating a rotating magnetic field by an applied single-phase commercial power supply;

A maneuvering winding connected between the two main windings and generating a starting torque during initial starting;

A starting capacitor for supplying starting power to the starting winding;

An operating capacitor for supplying the driving power insufficient to the starting winding in the case of a change in commercial power or a load to generate and maintain a rotating magnetic field;

And a drive circuit including a start relay for controlling whether or not a start power supply is supplied to the start winding of the start capacitor.

And the activation relay

A triac connected to the starting winding in series and controlling the supply of starting power to the starting winding by turning on and off;

A first comparator for detecting a voltage at both ends of the triac;

A second comparator for detecting a voltage at both ends of the starting winding;

A phase difference detection unit detecting a phase difference between voltage / current through the voltage sensed by the first comparator and the second comparator;

And detecting the rotational speed of the motor from the phase difference detected by the phase difference detection unit, and controlling the on / off of the triac according to the detection result.

A stator in which coils forming the main winding and the starting winding are wound;

A rotor disposed inside the stator and rotating in interaction with a magnetic field generated in the coil;

Covering both sides of the stator, and is fixed to each other, each of the inner center further comprises an upper cover and a lower cover formed with a seating portion for seating the ball bearing coupled to the rotating shaft of the rotor,

The stator is composed of a plurality of plates are laminated and coupled, the outer periphery of the plate is formed with a guide groove for guiding the plate is aligned and stacked, the surface of the plate is pressed into one side of the insertion groove is laminated on the other side Characterized in that the insertion protrusion is inserted into the insertion groove of the other plate,

The inner surface of the upper cover and the lower cover is characterized in that the stepped portion is seated on the upper and lower ends of the stator, respectively,

The cable for supplying commercial power to the drive circuit includes a power line for supplying commercial power to the main winding and a ground line for removing noise included in the commercial power source, wherein the ground line is fixedly coupled to the upper cover and the lower cover. Characterized in that connected to the fixing bolt,

The case in which the driving relay of the driving circuit is incorporated is provided with a through hole through which the fastening bolt is inserted.

The starter condenser type AC motor suitable for high starting torque according to the present invention having the above configuration has a starting capacitor and a starting relay to form a sufficient starting torque at initial start-up, and a sudden change in the power supply or a change in load during operation. In response, the driving capacitor supplies driving power to the main winding to generate and maintain a stable rotating magnetic field.

In addition, the start relay uses triacs to generate no electric arc, has a semi-permanent lifespan, detects the phase difference between voltage and current, and controls the on and off of the triacs so that the triac control is highly accurate and reliable. Excellent protection effect of condenser and starting winding.

In addition, the ground wire is introduced to remove the electrical noise, and the motor operation is excellent. The ground wire is easily connected to the cover through the fixing bolt, and the case with the built-in relay is molded with liquid resin such as epoxy or silicon, so that moisture, dust, It is protected from shock and stable operation without long-term trouble, and the case has a through hole, so that it can be easily attached and detached to a motor box or an enclosure.

And stator, rotor, upper and lower cover has a simple structure and simple assembly structure to reduce the manufacturing cost.

1 is a circuit diagram of a start relay according to the present invention.
2 is a drive circuit circuit diagram of a starting condenser-type AC motor according to the present invention;
3 is a perspective view of a starting condenser type AC motor according to the present invention;
4 is an exploded perspective view of the starting condenser-type AC motor shown in FIG. 3;

Hereinafter, a starting condenser type AC motor suitable for high starting torque according to the present invention will be described in more detail with reference to FIGS. 1 to 4.

As can be seen from the figure, the starting condenser-type AC motor according to the present invention includes a driving circuit 10 for supplying driving power to the coils (main winding and starting winding) wound around the stator, the stator 20, and the rotor ( 30), mechanical components including upper and lower covers 40, 50 and the like.

First, as shown in Fig. 2, the driving circuit 10 of the starting condenser-type AC motor according to the present invention includes main windings W1 and W2, starting winding W3, starting capacitor C1, starting relay RY, It comprises a driving capacitor (C2).

The main windings W1 and W2 are connected in series to an input terminal to which commercial power is input, and include a first main winding W1 and a second main winding W2 connected in series with each other.

When a single-phase commercial power source (that is, a driving power source) is input to the first and second main windings W1 and W2, a rotating magnetic field is generated, and the generated rotating magnetic field interacts with the rotor 30 to cause rotational torque. Rotating the rotor 30.

The start relay RY connects the start capacitor C1 and the start winding W3, and switches on and off to control whether the start capacitor C1 is supplied to the start winding W3. Specific circuit diagrams of the start relay will be described later.

The starting winding W3 is connected between the first main winding W1 and the second main winding W2, receives starting power through a starting capacitor C1, and supplies starting power and the main winding W1. , By increasing the magnetic flux amount of the magnetic field by the phase difference with the commercial power source applied to W2), it generates a starting torque of sufficient magnitude necessary for the initial rotation of the rotor at the initial startup.

The driving capacitor C2 is discharged when the capacity of the driving power applied to the main windings W1 and W2 is insufficient due to a change in the commercial power supply or a load change of the motor being operated, and thus the main windings W1 and W2 are discharged. Generate and maintain a rotating magnetic field. In other words, the motor is stably operated by continuously generating a rotating magnetic field of a constant size.

The driving capacitor C2 is connected in series to the starting winding W3, and discharge current is supplied to the second winding winding W2 among the starting winding W3 and the two winding windings W1 and W2 when the driving power supply is insufficient. Supply and generate and maintain the rotating magnetic field.

The driving capacitor C2 is connected in parallel with the starting capacitor C1, and the discharge power of the starting capacitor C1 and the driving capacitor C2 is added to the starting winding W3 as starting power at initial startup. It may be desirable to do so.

Fig. 1 shows a specific circuit diagram of the start relay RY. As shown in FIG. 1, the start relay RY used in the present invention includes a triac D1, first and second comparators U1 and U2, a phase difference detection unit PA, and a CPU.

The triac D1 is connected in series to the starting winding W3, and is switched on and off under the control of the CPU to control whether the charging power of the starting capacitor C1 is supplied to the starting winding W3 as the starting power. do.

The first and second comparators U1 and U2 sense voltages at both ends of the triac D1 and the start winding W3, respectively.

The first comparator U1 and the second comparator U2 respectively convert voltages applied to the motor through resistors R1 and R2 connected in parallel to the triac D1 and the starting winding W3 through the inverting terminal (−). The first comparator U1 receives the output voltages of the triac D1 and the starting winding W3 through the non-inverting terminal + through the resistors R3 and R4, respectively. The second comparator U2 senses a zero point voltage of the starting winding.

The phase difference detection unit PA receives a voltage between both ends of the triac D1 sensed by the first and second comparators U1 and U2 and the starting winding W3, and receives a voltage applied to the starting winding W3. The phase difference between voltage and current is detected and the result is sent to the CPU.

The CPU calculates the rotational speed of the motor rotor 30 from the phase difference transmitted by the phase difference detection unit PA, and applies a control signal to the gate terminal of the triac D1 through the driver TD according to the calculation result. To control the on and off of the triac D1.

When commercial power is applied to the motor for driving the motor, the triac D1 is turned on to start the motor.

When the motor starts, a phase difference of about 20 degrees to 30 degrees occurs between the voltage and current flowing in the start winding W3 depending on the winding method. And this phase difference forms the starting torque for the initial starting of a motor.

When the motor starts to start and the rotational speed of the rotor 30 increases, a voltage is induced by the interaction with the rotating rotor 30 in the starting winding W3, and the rotational speed of the motor is 60 to the maximum rotational speed. When it reaches 80%, the current of the starting winding W3 starts to decrease rapidly. When the current decreases due to the voltage induced in the starting winding W3, the phase difference between the voltage flowing in the starting winding W3 and the current increases. In addition, the CPU checks the time point when the phase difference between the voltage and the current rapidly increases, turns off the triac D1 through the driver TD, and disconnects the connection between the start capacitor C1 and the start winding W3. The rotor 30 is rotated by generating a magnetic field using only commercial power applied to two main windings W1 and W2. In addition, when the phase difference does not occur for a predetermined time or the phase difference is 10 degrees or less during operation of the motor, the CPU determines that the motor is in a restrained state (that is, a state in which the rotation of the rotor is disturbed). The triac is turned off immediately to protect the maneuver winding (W3) and maneuvering capacitor (C1).

For reference, in FIG. 1, reference numeral PS denotes a power supply for supplying driving power required for driving the CPU, and C denotes a capacitor for smoothing the output power of the power supply to the CPU.

Hereinafter, the mechanical configuration of the starting condenser type AC motor according to the present invention will be described in more detail with reference to FIGS. 3 and 4.

3 and 4, the starting condenser-type AC motor according to the present invention includes a stator 20, a rotor 30, upper and lower covers 40 and 50, and a built-in starting relay RY for protection. It includes a case 60.

The stator 20 is wound with a coil W forming the main windings W1 and W2 and the starting winding W3, and the rotor 30 is disposed inside.

The stator 20 is configured by stacking a plurality of plates 21.

Inside the plate 21, winding grooves 22 are formed at equal intervals along the inner circumference to hold the coils W so as to be wound without being separated, and on the outside, the plates 21 are aligned and stacked in place. A plurality of guide grooves 23 for guiding are formed.

In addition, the surface of the plate 21 is pressed to form an insertion groove 24 and an insertion protrusion 25. That is, the surface of the plate 21 is pressed to form an insertion groove 24 on one surface, and an insertion protrusion 25 is formed on the opposite surface. Thus, the stacked plates 21 are inserted and seated in the insertion grooves 24, and the stacking coupling force between the plates 21 is increased, so that the plates 21 are vertically aligned and stacked without inclination, and are stacked. Some plates 21 are not later released from the stacked plate assembly (ie the stator).

The rotor 30 is disposed inside the stator and has a magnet built therein. Thus, when the driving power is supplied to the coil W (that is, the main winding and the starting winding) of the stator 20 and a magnetic field is generated, the rotor 30 rotates by interaction with the magnetism of the built-in magnet. .

The rotor 30 includes a main body 31 incorporating a magnet, a rotating shaft 32 crossing the upper and lower sides of the main body 31, and ball bearings 33 provided on both sides of the rotating shaft 32, respectively. It is done by

The upper and lower covers 40 and 50, that is, the upper cover 40 and the lower cover 50 cover both sides (upper and lower) of the stator 20 and are fixed to each other through fixing bolts 70. .

And in the inner center of the upper cover 40 and the lower cover 50, a seating portion 51 for mounting both ball bearings 33 of the rotor 30 is formed, respectively,

On the inner surface of the upper cover and the lower cover is formed with a stepped portion 52, the upper end and the lower end of the stator is caught;

On the outer surface of the upper cover and the lower cover are formed receiving portions 43 and 53 for receiving the head 71 and the nut 72 of the fixing bolt 70, respectively,

In the side wall of the lower cover 50 is formed a wire hole 54 through which the wires (L) connected to the coil (W) wound around the stator 20 is inserted, the wire hole 54 In order to prevent the wires (L) from being damaged, a protective member 80 of rubber material is combined,

The bottom surface of the lower cover 50 is formed with a heat radiation hole 55 for quickly discharging heat generated during operation to the outside.

As shown in the drawing, the AC motor of the present invention has a structure in which upper and lower cover portions 40 and 50 surround both upper and lower ends of the stator 20 and expose the side surface of the stator 20 to the outside. The release effect is excellent, and the material cost of the covers 40 and 50 can be reduced.

In addition, the upper cover 40 and the lower cover 50, which are spaced apart from each other by a predetermined distance to cover the upper and lower parts of the stator 20, are firmly fixed to each other through the fixing bolt 70 and the nut 72, and cover the entire stator. Support and fix the stator accordingly.

The cable for supplying commercial power to the driving circuit 10 includes power lines L1 and L2 for supplying commercial power (that is, driving power) to the main windings W1 and W2, and are included in the commercial power input. It comprises a ground line (L3) for removing the noise, the ground line (L3) is inserted into the fixing bolt 70 and tightened with a nut (72) is simply connected to the lower cover (50).

In the case 60 in which the starting relay RY is built and protected, the opening 60 is molded with a liquid epoxy or silicon after the starting relay RY is incorporated. Thus, by blocking the contact between the starting relay RY and the outside, there is no risk of malfunction or damage due to dust or moisture penetrating into the starting relay RY. There is no risk of swinging or malfunctioning.

In addition, a through hole 61 penetrating up and down is formed at the center of the case 60, and the start relay RY can be easily installed and detached from the inner box or the enclosure of the motor or a long distance from the outside through a fastening bolt. have.

In the above description of the present invention with reference to the accompanying drawings has been described for the starting condenser-type AC motor having a specific shape and structure, the present invention can be variously modified and changed by those skilled in the art, such variations and modifications the present invention It should be interpreted as falling within the protection scope of.

10: drive circuit W1, W2: main winding
W3: Starting winding C1: Starting capacitor
C2: Operation capacitor RY: Starting relay
D1: Triac U1, U2: Comparator
PA: Phase difference detector CPU: CPU
20: stator 21: plate
23: guide groove 24: insertion groove
25: insertion protrusion
30: rotor 31: main body
32: rotating shaft 33: ball bearing
40, 50: upper and lower cover 51: seating portion
52: step 53: receiving groove
60: case 61: through hole
70: fixing bolt

Claims (4)

Two main windings for generating a rotating magnetic field by an applied single-phase commercial power supply;
A starting winding which is connected between the two main windings and generates starting torque during initial starting;
A starting capacitor for supplying starting power to the starting winding;
An operating capacitor for supplying the driving power insufficient to the starting winding in the case of a change in commercial power or a load to generate and maintain a rotating magnetic field;
A driving circuit including a starting relay for controlling whether a starting power is supplied to the starting winding of the starting capacitor;

A stator in which coils forming the main winding and the starting winding are wound;
A rotor disposed inside the stator and rotating in interaction with a magnetic field generated in the coil;
Covering both sides of the stator, and is fixed to each other, each of the inner center further comprises an upper cover and a lower cover formed with a seating portion for seating the ball bearing coupled to the rotating shaft of the rotor,

The stator is composed of a plurality of plates are laminated and coupled, the outer periphery of the plate is formed with a guide groove for guiding the plate is aligned and stacked, the surface of the plate is pressed into one side of the insertion groove is laminated on the other side Characterized in that the insertion protrusion is inserted into the insertion groove of the other plate,

The inner surface of the upper cover and the lower cover is characterized in that the stepped portion is seated on the upper and lower ends of the stator, respectively,

The cable for supplying commercial power to the drive circuit includes a power line for supplying commercial power to the main winding and a ground line for removing noise included in the commercial power source, wherein the ground line is fixedly coupled to the upper cover and the lower cover. Characterized in that connected to the fixing bolt,

A starter condenser type AC motor for high starting torque, characterized in that a through hole through which a fastening bolt is inserted is formed in a case having a built-in start relay of the drive circuit. The method of claim 1,
The activation relay
A triac connected to the starting winding in series and controlling the supply of starting power to the starting winding by turning on and off;
A first comparator for detecting a voltage at both ends of the triac;
A second comparator for detecting a voltage at both ends of the starting winding;
A phase difference detection unit detecting a phase difference between voltage / current through the voltage sensed by the first comparator and the second comparator;
And a CPU for detecting a rotational speed of the motor from the phase difference detected by the phase difference detection unit and controlling the on-off of the triac according to the detection result. delete delete

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