JPS6014587B2 - double winding electric motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention improves the regenerative braking characteristics of a double-wound electric motor.

As is well known, a DC double-wound electric motor basically has a structure that allows easy regenerative braking, which will be explained based on FIG.

FIG. 1 shows a well-known circuit configuration of a double-wound electric motor A, with reference numeral 1
is the armature, 2 is the direct winding field, 3 is the split winding field, and 4 is the battery.

If the excitation of the winding field 3 is strengthened while the electric motor A is rotating, or the rotation speed is increased by an external force, the back electromotive voltage transferred to the armature 1 will be increased by field excitation (direct winding, Since it is proportional to the sum of both winding fields 2 and 3) and the rotation speed, the back electromotive force naturally increases in both cases and becomes higher than the power supply voltage, causing the armature current to change direction and become more connected to the power source than the motor. flow backwards.

This reverse current also reverses the direction of the torque, causing regenerative braking to occur. By applying this characteristic, double-wound electric motors have a proven track record of being adopted as train motors for electric railways that operate plowing operations in the mountains.

However, if the wiring is connected as shown in Figure 1, the armature current will reverse and transfer to regenerative braking, and at the same time, the magnetism of the excitation of the direct-wound field 2 will also be reversed and will be opposite to the excitation polarity of the split-wound field 3. It works to weaken this.

Therefore, there is a drawback that the regenerative braking torque and the regenerative current are weakened by themselves. In the case of a train, if the driver requires brake torque, there is no problem because the driver operates the controller to reverse the connection of the direct winding field 2.

The present invention solves the above drawbacks and automatically performs regenerative braking when the speed of the vehicle exceeds a certain value and the armature 1 is reversely driven, for example on a downhill slope, without changing the connection by the driver. is designed to work effectively, and in the direct winding field 2 of the double winding electric motor A shown in FIG.
As shown in FIG. 2, diodes 5 are connected in parallel, and the diodes 5 are connected so that the diode 5 becomes reverse magnetic when the motor A is in force, and becomes normal polarity during regenerative braking.

Therefore, when the electric motor A is dynamic, that is, when the armature current flows in the direction of the polarity of the power supply, the diode 5 has the opposite polarity, so it is as if it exists and has no effect at all, but it affects regenerative braking. Since the current has forward polarity with respect to the armature current, it automatically shunts the direct winding field 2, which effectively eliminates the reverse excitation of the direct winding field 2 and weakens the excitation of the shunt field 3, which is an undesirable effect. It can be prevented.

Although the present invention is effective for use with any double-wound electric motor that generates regenerative braking, it is particularly suitable for small battery-powered motors such as golf carts used in places with many ups and downs such as golf courses.

That is, in a golf cart vehicle, (1) Since a small battery is used as an energy source, it is desirable to reduce power consumption as much as possible. ■ The area where it is used is always hilly.

■ Most of the machines are pushed by hand and the speed varies, especially downhill speed assists, which are undesirable as they drag the operator.

For these reasons, regenerative braking is absolutely necessary.

However, this type of battery car is 12V to 24V, 25
Because it uses a low pressure motor of 0 to 300 watts,
When the direct winding field current that is in series with the armature circuit is used for regenerative braking due to low voltage and large current loads, it is technically undesirable to reverse the current using a small conductor, etc., as it may cause drop in the conductor contact. It should also be avoided since the people handling it are female laborers who have virtually no electrical knowledge. The present invention is non-contact,
It can be said to be extremely useful in that effective regenerative braking can be obtained automatically when going downhill without any operation.

[Brief explanation of drawings]

FIG. 1 shows the circuit configuration of a conventional double-wound electric motor, and FIG. 2 shows the circuit configuration of the double-wound electric motor of the present invention. A: Electric motor, 1: Armature, 2
...Direct winding field, 3...Divided winding field, 4...Battery. Figure 1 Figure 2

Claims (1)

[Claims] 1. A diode 5 is connected in parallel to the direct-wound field 2 of the multi-wound electric motor A, and this diode 6 is connected so that the polarity is reversed when the motor A is powered and the polarity is forward during regenerative braking. Winding motor.