JPS5952607B2 - Power supply device for running body - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a power supply device for a traveling body having a three-phase motor such as a linear motor or cage-type induction motor as a drive source.

The first example of this type of traveling body is usually well known.
There is a running body using an on-vehicle primary single-sided linear motor as shown in the figure.

In FIG. 1, 1 is a trolley, 2 is a running wheel, 3 is a linear motor stator, 4 is a cooling fan for cooling the linear motor stator 3, 5 is a linear motor secondary conductor, 6 is a running rail, 7 is the power supply line running the entire length of the running path, 8 is the brush,
It is a collector for things like pantographs.

In the traveling body shown in Fig. 1, the current is generated by applying multiphase alternating current (usually three-phase) to the linear motor stator 3 via a suitable current feeding/collecting device 7, 8 consisting of a rigid trolley and a current collecting brush. Thrust is generated by the interaction between the moving magnetic field and the eddy current induced in the linear motor primary conductor 5 by the moving magnetic field, causing the bogie 1 to run via the running wheels 2 and the running rail 6, thus causing this running. It uses its body as a traction device.

Speed control in these linear motor running bodies is usually performed by primary voltage control as the simplest speed control method.

Incidentally, as shown in FIG. 2, the thrust characteristics of a linear motor exhibit a higher resistance characteristic than that of a normal induction motor, so primary voltage control is suitable.

On the other hand, when the linear motor traveling body is in operation, the linear motor stator 3 is energized, thereby causing heat loss such as coil copper loss and iron loss.

Nevertheless, unlike a normal rotating machine, a linear motor essentially does not have a self-cooling function, so it is essential to cool the linear motor stator 3 with a forced cooling fan 4.

By the way, as a power supply/collection device for such a near-motor running body, a method is mainly adopted in which current is collected from a power supply line 7 extending along the entire length of the running path via a collector 8 such as a brush or a pantograph.

However, in the conventional power supply system, a ground conversion type power supply system is generally used to reduce the running weight as much as possible, so as mentioned above, the three-phase power supply is controlled by voltage.
It was necessary to provide a five-wire current collector that includes at least a wire current collector and a two-wire current collector for a single-phase power source with a constant voltage for driving the cooling fan 4.

Conventional devices that employ five-wire current collectors have drawbacks such as increased running weight and increased installation space because they must be equipped with five sets of current collectors. The cost increased because it was necessary to install several power supply lines, and there were significant drawbacks in terms of reliability and maintainability.

The present invention has been made with the aim of effectively eliminating these drawbacks, and controls the driving force of a three-phase induction motor, such as thrust control of a linear motor, by controlling the voltage of one phase of a three-phase power supply. At the same time, by using the other two phases, which are not voltage controlled, as a constant voltage power source, it is possible to obtain a three-phase variable voltage power source and a single-phase constant voltage power source at the same time through three-wire current collection. be.

An example of the present invention will be described below in detail with reference to the drawings. In FIG. 3, 9 is a three-phase power transformer, and 10 is a voltage control device.

The voltage control device 10 has thyristors (SCR) 11 connected in antiparallel as shown in FIG.
is phase-controlled by the gate circuit 12.

In the configuration shown in FIG. 3, the voltage control device 10 includes three-phase U,
It is inserted only into one of the V and W phases, for example, the U phase,
The voltage of this U phase is controlled by phase control.

The method is to change the firing angle of the thyristor (SCR) 11 by controlling the thyristor (SCR) 11 with a gate circuit 12, thereby changing the effective value of the phase voltage of the U phase to the fifth
As shown in the figure, it is continuously controlled from a maximum value equal to the other two uncontrolled phases, ie, the ■ and W phases, to zero.

When the control angle α in FIG. 5 is 0 (or when the thyristor 11 is fully fired), U.

(2) The W phase is completely balanced, and the linear motor generates 100% thrust for a predetermined applied voltage.

On the other hand, when the control angle α becomes 180 degrees, both thyristors connected in antiparallel are disconnected.
The voltage applied to the linear motor stator 3 is only two phases, V and W, and the thrust generated by the linear motor is zero.

FIG. 6 shows the changes in thrust with respect to these changes in control angle α.

Further, FIG. 7 shows the line voltages of the other two phases (1) and (W) when the control angle α of the U phase is controlled between 0 and 180 degrees.

As is clear from FIG. 7, even if the phase voltage of one of the three phases is controlled between 0 and 100%, the line voltages of the other two phases are kept almost constant.

Therefore, if this two-phase power source is turned into a single-phase power source, it can be used as a single-phase constant voltage power source for cooling fans of linear motors, etc.

As described above, according to the present invention, by controlling the voltage of one phase of the three-phase power supply, it is possible to obtain the same thrust control effect as three-phase voltage control under equal constraints, and also to control the voltage of one phase of the three-phase power supply. It can be used as a single-phase constant voltage power supply.

Therefore, in a running vehicle, it is possible to use both a three-phase variable voltage power source and a single-phase constant voltage power source by using a three-wire current collector.
Compared to the conventional 5-wire current collector type, the current feeding and collecting device can be greatly simplified, which not only has great advantages in terms of cost and maintenance, but also greatly improves the reliability of the device.

In this case, the voltage of one of the three phases is controlled, and the other two phases, which are not controlled, are loaded with a cooling fan, etc., which creates an unbalanced load on the power supply, but this does not affect the normal power supply capacity. In comparison, the control capacity is very small, so its influence can be considered almost negligible.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram showing an example of a normal running body, Fig. 2 is a thrust characteristic diagram during voltage control in a near motor, and Fig. 3 is a connection diagram showing an example of a power supply device for a running body according to the present invention. Figure 4 is a connection diagram showing the detailed configuration of the voltage control device, and Figure 5 is a connection diagram showing the detailed configuration of the voltage control device.
The figures are a voltage waveform diagram during phase control as shown in FIG. 3, FIG. 6 is a thrust characteristic diagram during voltage control, and FIG. 7 is a line-to-line voltage characteristic diagram of two phases that are not controlled. 1: Trolley, 2: Traveling wheels, 3: Linear motor stator,
4: Cooling fan, 5: Linear motor secondary conductor, 6: Running rail, 7: Power supply line, 8: Current collector, 9: Power transformer, 10: Voltage control device, 11: Thyristor (SCR),
12: Gate circuit.

Claims (1)

[Claims] In a running body that has a three-phase electric motor as a running drive source controlled by primary voltage control, voltage control is applied to only one phase of the three-phase power supply, and the other two phases are connected to a single-phase constant voltage inside the running body. A power supply device for a traveling body characterized by being used as a power source.