JPS5814159B2 - Japanese cypress - Google Patents

Description

[Detailed description of the invention] The present invention relates to the control of a wound single-phase induction motor.

Single-phase induction motors cannot start automatically, so various starting methods are used. Typical examples include capacitor starting method, shaded ring starting method, etc., which require a capacitor for starting. Or the stator needs to have a special structure.

Furthermore, conventional single-phase induction motors are not capable of operating at higher than synchronous speeds, reversible operation, or braking operation.

Therefore, the object of the present invention is to use a wound single-phase induction motor,
It is an object of the present invention to provide a control device for a wound single-phase induction motor that can generate sufficient starting torque and also allows reversible operation, braking operation, and operation at speeds higher than synchronous speed.

Below, in explaining the present invention, the principle of the present invention will be explained.

In the wound type single-phase induction motor (hereinafter simply referred to as the motor) applied to the present invention, the secondary winding is connected to the terminal U1 as shown in FIG.
, v1 and terminals U2, v2, and has a pair of windings wound at 90 degrees displacement from each other.

However, if it is assumed that the alternating magnetic field generated by the stator winding (not shown) is generated in the vertical direction in FIG. If the electric current 1 is supplied from the terminal U1 in the direction of v1 as shown in the figure, the rotor will generate rotational force in the counterclockwise direction.

Also, once the rotor has rotated 90 degrees from the position shown in the illustration, then connect terminal ■2.
A current is supplied from the terminal U2 to the terminal U2.

That is, each secondary winding rotates in a desired direction by changing the current direction every 1800 turns.

As can be seen from the principle diagram in Figure 1, in order to rotate the rotor in the desired direction, the direction of the current can be determined by detecting the position of the secondary winding and the direction of the alternating magnetic field at that time. .

In order to detect the position of the secondary winding, a position detection device is used, which includes, for example, a magnetic body MG connected to the rotor, and proximity switches SW1SW2, for example, arranged opposite to the magnetic body MG at 90° intervals.

The output signal of proximity switch SW1 is A, proximity switch SW
Let the output signal of 2 be B, and this signal is the rotation angle ω of the rotor.
(Counterclockwise rotation), this signal is generated as shown in FIG. 2, and this signal is applied to a logic circuit to be described later to derive a signal for converting the current direction.

If the reference position is a position where the rotor is displaced 90° clockwise from the position shown in Figure 1, the range in which signal A is generated is the range in which it rotates 180° counterclockwise from this reference position.
Signal B is generated with a further delay of 90 degrees, and the signal B is generated from 900 to 2710.
The signal is in the range of 100°, and its generation timing is shown in FIG.

On the other hand, the direction of the alternating magnetic field can be detected from the primary voltage phase of the motor, and if the primary voltage is ERT, the field detection device FD, which will be described later, generates signals F and F shown in FIG.
During the period when the signal F is generated, the direction of the alternating magnetic flux Φ is the first.
If the direction is as shown in the figure, the direction is reversed during the period in which the signal Y is generated.

The present invention is to control the secondary current of a motor according to the output signals of the above-mentioned position detection device and field detection device, and one embodiment of the present invention will be described below with reference to FIG. do.

In Figure 4, RT is a single-phase AC power supply bus, FD, PS
o indicates the above-mentioned field detection device and position detection device, where the position detection device PSo includes the above-mentioned magnetic body MG and proximity switches SW, SW2, and generates signals A and B.

The logic operation circuit LO to which the output signals of the field detection device FD and the position detection device PSo are applied is the power conversion device PC1, P.
Thyristors (01P~v1N) (U2
The ignition signal to be given to the P-V2N is calculated and derived.

Therefore, the secondary winding terminal U1 of the motor IM is connected to the thyristor U.
1P is connected to the series connection point of U and N, the secondary terminal v1 is connected to the series connection point of thyristors v1P and v1N, and the secondary terminal U2v2 is connected to the power conversion device PC2 having exactly the same configuration as the power conversion device PC1. Connect as shown.

The cathodes of thyristors U1P and V1P are commonly connected to one end of smoothing reactor DCL1.

The other end of the smoothing reactor DCL1 is commonly connected to the anodes of thyristors B1N and T1N, and
Connect the secondary winding of the transformer Tr1 whose primary winding is connected to the AC power buses R and T between the cathodes of the transformer R1N and thyristor R1P to the thyristor T1N, and connect the thyristor T1P to the thyristor T1N in series with the polarity shown. and further connect the cathodes of thyristors R1P and T1P and thyristor 0
Connect the anodes of 1N and V1N in common.

Power converter PC2 is also configured in the same manner as described above.

Hereinafter, the operation of the present invention having the above-mentioned configuration will be explained.

The logic operation circuit LO derives firing signals for the thyristors U1P-V1N and U2P-V2N from the signals A, B and F, F.

In other words, derive the signals that fire the thyristors UP and V2N with the signals B-F+B-F that fire the thyristors UP and V2N, and the signals that fire the thyristors UP and V2N. This signal is given as a firing signal for each thyristor indicated by the same symbol.

Therefore, when the electric motor IM is rotating in the counterclockwise direction at the rotation frequency shown by sin θ in FIG. 5, the energization period of each thyristor becomes as shown in FIG. 5 U1P-v1N, U2P to V2N.

Here, A-F+A-F connects thyristors U1P and V1N, and A
-F+A-F for thyristor V1P, U1N, B-F1B, 〒 for thyristor U2P, v2N, π/F1B-F
If the thyristors v2P and v2N are ignited, the electric motor IM
will rotate clockwise.

Also, for example, if the electric motor IM is rotating in a counterclockwise direction,
When operating in a cyclical manner (Bas A-F
1P, v1N, thyristor V1 with A-F+A-F
P, 01N, thyristor U2P with B-F+B-F
, V2N, thyristor v2P,v with ■・F1B-F'
2N is ignited and the power induced in the secondary of the motor IM is regenerated into one source via the transformer TrITr2.

Furthermore, the electric torque and braking torque are controlled by the thyristor R1N-
T, P, R2 The phase on the NET2P side is polished, and the motor IM
It can be arbitrarily adjusted by controlling the current flowing through the secondary windings U1v1 and U2v2.

Furthermore, in the above explanation, the primary winding of the motor IM is one winding, but in order to prevent armature reaction, a compensating winding is provided and the primary winding is two windings to obtain even better characteristics. I can do it.

As explained above, the present invention can generate sufficient starting torque, and also allows reversible operation. It is possible to provide a control device for a wound single-phase induction motor that can perform braking operation and operate at a speed higher than the synchronous speed.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining the operating principle of the present invention, FIG. 2 is a characteristic diagram of the position detection device used in the present invention, FIG. 3 is a characteristic diagram of the field detection device used in the present invention, and FIG. The figure is a connection diagram showing one embodiment of the present invention, and FIG. 5 is a diagram for explaining the operation of the present invention. IM...Wound single phase induction motor, FD...
...field detection device, PSo...position detection device,
PC1, PC2... Power converter.

Claims (1)

[Claims] 1. A wound type single-phase induction motor consisting of a stator consisting of at least one winding to which a single-phase AC voltage is applied and a rotor having a plurality of secondary windings, and a position detection device for detecting the position of the secondary winding. a field detection device for detecting the direction of an alternating magnetic field generated by the windings of the stator, one of which is connected to each of the secondary windings and the other connected to the single-phase AC power bus; A control device for a wound single-phase induction motor, comprising a plurality of power conversion devices controlled by an output signal of the field detection device.