JP4491895B2 - Capacitor induction motor starter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a starting device for a capacitor induction motor, and more particularly to a starting circuit.
[0002]
[Prior art]
FIG. 4 is a connection diagram showing an example of a conventional capacitor induction motor starting device, and FIG. 5 is an explanatory diagram of a conventional capacitor induction motor starting device.
The conventional capacitor induction motor starter is configured by connecting a main winding 2a and an auxiliary winding 2b in which a driving capacitor 3 is connected in series to a power source 1 in parallel to form a capacitor induction motor 2. A resistance component 5 is provided between the connection point of the main winding 2 a and the operating capacitor 3 and one end of the power source 1.
A starting capacitor 4 having one end connected to the connection point between the auxiliary winding 2b and the operating capacitor 3 is provided.
Then, one end of the power source 1 is connected to the other end of the starting capacitor 4 at the start, while one end of the power source 1 is switched during operation, and connected to the connection point of the main winding 2a and the operating capacitor 3. A relay 6 for short-circuiting the resistance component 5 is provided.
[0003]
When used in a compressor as in the above-described conventional example, an excessive current flows at the start, and accordingly, a power supply voltage drop is prevented from occurring, and this excessive current and voltage drop are beginning to be regulated in several overseas countries. It deals with that.
However, when the starting time becomes longer, the torque of the capacitor induction motor 2 increases and the voltage across the starting capacitor 4 increases.
Depending on the timing at which the maximum voltage between both ends of the relay 6 is switched from when the relay 6 is started to when the relay 6 is operated, there is a problem in that the overvoltage may exceed the withstand voltage of the starting capacitor 4.
[0004]
[Problems to be solved by the invention]
An object of the present invention is to provide a starting device for a capacitor induction motor that reduces excessive current during starting and improves the reliability of the starting capacitor.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, a main winding and an auxiliary winding, in which an operating capacitor is connected in series, are connected in parallel to a power source, and the connection point between the main winding and the operating capacitor. Providing a resistance component between one end of the power source, providing a starting capacitor having one end connected to a connection point of the auxiliary winding and the operating capacitor, and at the other end of the starting capacitor at the time of starting A starting device for a capacitor induction motor, wherein one end of a power source is connected, one end of the power source is switched during operation, and a relay that short-circuits the resistance component is connected to a connection point between the main winding and an operating capacitor. In
A resistance component voltage sensor is provided at both ends of the resistance component, and when the detection voltage of the resistance component voltage sensor drops to a predetermined voltage after startup, the relay is switched from startup to operation.
[0006]
Or, it is configured by connecting in parallel a main winding and an auxiliary winding in which an operating capacitor is connected in series to a power source, a connection point between the main winding and the operating capacitor, and one end of the power source. A starting capacitor having one end connected to the connection point of the auxiliary winding and the operating capacitor, and connecting one end of the power source to the other end of the starting capacitor at the time of starting On the other hand, in the starter of the capacitor induction motor, switching one end of the same power supply during operation, connected to the connection point of the main winding and the operation capacitor, and provided with a relay for short-circuiting the resistance component,
A starting capacitor voltage sensor is provided at both ends of the starting capacitor, and when the detection voltage of the starting capacitor voltage sensor rises to a predetermined voltage, the relay is switched from starting to operating.
[0007]
The relay is a bidirectional thyristor having a pair of one ends connected so that one is energized and the other is shut off.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described in detail based on examples with reference to the accompanying drawings.
FIG. 1 is a connection diagram showing an embodiment of a capacitor induction motor starting device according to the present invention, FIG. 3 is an explanatory diagram of the capacitor induction motor starting device according to the present invention, and (b) shows a resistance component with respect to time. Indicates the voltage at both ends.
Here, 1 is a power source, 2 is an electric motor body, 2a is a main winding, 2b is an auxiliary winding, 3 is an operation capacitor, 4 is a starting capacitor, 5 is a resistance component, 6 is a relay, and 7 is a resistance component voltage. Indicates a sensor.
In addition, the code | symbol of the same part as the past is the same.
[0009]
A capacitor induction motor 2 is configured by connecting in parallel a main winding 2 a and an auxiliary winding 2 b in which an operating capacitor 3 is connected in series to a power source 1.
A resistance component 5 is provided between the connection point of the main winding 2 a and the operating capacitor 3 and one end of the power source 1.
A starting capacitor 4 having one end connected to the connection point between the auxiliary winding 2b and the operating capacitor 3 is provided.
Then, one end of the power source 1 is connected to the other end of the starting capacitor 4 at the start, while one end of the power source 1 is switched during operation, and connected to the connection point of the main winding 2a and the operating capacitor 3. A relay 6 for short-circuiting the resistance component 5 is provided.
[0010]
Here, a resistance component voltage sensor 7 is provided at both ends of the resistance component 5, and when the detected voltage of the resistance component voltage sensor 7 drops to a predetermined voltage after starting, the relay 6 is switched from starting to operating. I am doing so.
[0011]
Next, functions and effects of the present invention will be described.
When the detection voltage of the resistance component voltage sensor 7 becomes lower than a predetermined voltage, the relay 6 is switched. At this time, the voltage across the starting capacitor 4 slightly increases and the torque increases. is there.
[0012]
However, the voltage is sufficiently lower than the withstand voltage of the starting capacitor 4, and for this reason, switching can be performed from the start to the operation without being an overvoltage of the starting capacitor 4.
[0013]
FIG. 2 is a connection diagram showing another embodiment of the capacitor induction motor starting device according to the present invention, FIG. 3 is an explanatory diagram of the capacitor induction motor starting device according to the present invention, and FIG. Indicates the voltage across the capacitor.
In the case of this embodiment, the relay 6 of the motor body is a bidirectional thyristor 6a, 6b to which a pair of one ends are connected so that one is energized and the other is disconnected.
The bidirectional thyristors 6a and 6b are switched from starting to operating. A starting capacitor voltage sensor 8 is provided at both ends of the starting capacitor 4, and the detected voltage of the starting capacitor voltage sensor 8 is a predetermined voltage. To do when it rises.
[0014]
Next, functions and effects of the present invention will be described.
Since the bidirectional thyristors 6a and 6b are used, it is possible to prevent the occurrence of electrical noise and abnormal high voltage during switching due to chattering of mechanical contacts, and the starting device can be operated stably.
Further, the bidirectional thyristors 6a and 6b are switched from starting to operating when the detection voltage of the starting capacitor voltage sensor 8 rises to a predetermined voltage. It is possible to use the starting capacitor 4 that has been determined, and the cost of the starting capacitor 4 can be reduced and the reliability of the electric motor body 2 can be improved.
[0015]
【The invention's effect】
As described above, in the present invention, the main winding and the auxiliary winding in which the operating capacitor is connected in series are connected in parallel to the power source, and the main winding and the operating capacitor are connected. A resistance component is provided between the point and one end of the power source, and a starting capacitor is provided with one end connected to a connection point between the auxiliary winding and the operating capacitor. One end of the power source is connected while one end of the power source is switched during operation, a capacitor induction motor is provided which is connected to a connection point between the main winding and the operating capacitor and short-circuits the resistance component. In the device
A resistance component voltage sensor is provided at both ends of the resistance component, and when the detection voltage of the resistance component voltage sensor drops to a predetermined voltage after startup, the relay is switched from startup to operation.
As a result, it is possible to provide a starting device for a capacitor induction motor that reduces excessive current during starting, reduces the cost of the starting capacitor, and improves the reliability of the motor body.
[Brief description of the drawings]
FIG. 1 is a connection diagram showing an embodiment of a capacitor induction motor starting device according to the present invention.
FIG. 2 is a connection diagram showing another embodiment of a capacitor induction motor starting device according to the present invention.
3A and 3B are explanatory diagrams of a starting device for a capacitor induction motor according to the present invention, in which FIG. 3A shows a voltage across a starting capacitor with respect to time, and FIG. 3B shows a voltage across a resistance component with respect to time.
FIG. 4 is a connection diagram showing an example of a conventional starting device for a capacitor induction motor.
FIG. 5 is an explanatory diagram of a conventional starter for a capacitor induction motor.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Power supply 2 Electric motor body 2a Main winding 2b Auxiliary winding 3 Operation capacitor 4 Start capacitor 5 Resistance component 6 Relay 6a Bidirectional thyristor 6b Bidirectional thyristor 7 Resistance component voltage sensor 8 Start capacitor voltage sensor

Claims (3)

A main winding and an auxiliary winding, in which an operating capacitor is connected in series, are connected in parallel to the power source, and a connection point between the main winding and the operating capacitor and one end of the power source Providing a resistance component between them, providing a starting capacitor having one end connected to the connection point of the auxiliary winding and the operating capacitor, and connecting one end of the power source to the other end of the starting capacitor at the time of starting; In the starter of the capacitor induction motor, which is provided with a relay for switching one end of the same power source during operation, connected to a connection point of the main winding and the operation capacitor, and short-circuiting the resistance component,
Capacitor induction, wherein a resistance component voltage sensor is provided at both ends of the resistance component, and when the detection voltage of the resistance component voltage sensor drops to a predetermined voltage after startup, the relay is switched from startup to operation. Electric motor starter. A main winding and an auxiliary winding, in which an operating capacitor is connected in series, are connected in parallel to the power source, and a connection point between the main winding and the operating capacitor and one end of the power source Providing a resistance component between them, providing a starting capacitor having one end connected to the connection point of the auxiliary winding and the operating capacitor, and connecting one end of the power source to the other end of the starting capacitor at the time of starting; In the starter of the capacitor induction motor, which is provided with a relay for switching one end of the same power source during operation, connected to a connection point of the main winding and the operation capacitor, and short-circuiting the resistance component,
A capacitor comprising a starting capacitor voltage sensor at both ends of the starting capacitor, and when the detection voltage of the starting capacitor voltage sensor rises to a predetermined voltage, the relay is switched from starting to operating. Induction motor starting device. The starter for a capacitor induction motor according to claim 1 or 2, wherein the relay is a bidirectional thyristor to which a pair of one ends are connected so that one is energized and the other is disconnected.

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