JPH01318540A - Motor for rolling stock - Google Patents

Abstract

PURPOSE:To improve motor efficiency and to make a motor small in size and light in weight by using a superconducting coil as a stator field winding. CONSTITUTION:A superconducting coil 21 is used for the stator section of a motor for rolling stocks. There will therefore be no heat loss in this part at all. The heat loss is so limited only to an external excitation circuit that the total heat loss will be reduced and the improvement to efficiency can be achieved. In the superconducting coil 21 the current density can be taken so thick that the large-scale reduction of a coil size will be allowed and by miniaturizing the stator section the miniaturization and weight-lightening of the motor as a whole can be achieved.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a vehicle electric motor.

[Conventional technology]

Figure 5 is a plan view of the bogie that is the traveling device at the bottom of the vehicle;
The figure is a cross-sectional view of a conventional electric motor, where (a) is a series-wound electric motor, and (b)
) shows the case of a compound-wound motor, and (Q) shows the case of a shunt-wound motor. In the figure, (1) is the electric motor, (2) is the joint, (
3) is a reduction gear, (4) is an axle, (5) is a wheel, (6)
(b) is a series winding coil, (b) is a shunt winding coil, α
1 is the stator field core, α→ is the commutator coil, (to) is the commutator core, cIQ is the rotor conductor, αη is the rotor core, (to)
is a magnetic frame.

The 0 motor whose operation will be explained next has a stator winding (6).
Alternatively, a magnetic flux is generated in the stator core (to) by the sum of the product of the current value flowing in @ and the number of turns, and the magnetic flux is proportional to the product of the current flowing in the rotor conductor αQ arranged at right angles to this magnetic flux. Rotational torque is generated. In general, the sum of the product of the current and the number of turns in the stator winding (B) or (6) is called an ampere turn, and the relationship between this ampere turn and the magnetic flux generated in the stator core (to) is shown in Figure M. exist. In addition, the product of the number of revolutions of the magnetic flux and a constant determined by the structure is called the back electromotive force, and the current value obtained by subtracting the back electromotive force from the terminal voltage and dividing it by the internal resistance value is the current value of the rotor conductor 0Q. flows to

That is, the relationship shown by equation (1) holds true.

E = Ea + engineering aX R----1-(1)E:
Motor terminal voltage E. In particular, the rotational speed N changes, and the rotational speed N is determined at the point where the rotational resistance at the rotational speed N and the rotational torque determined by the product of the magnetic flux φ and the current factor a match by about 9. Normally, the terminal voltage E is determined by the power supply voltage (overhead line or third rail), so the rotation speed control requires adjustment of the magnetic flux φ, that is, adjustment of the stator ampere turn v@.

[Problem to be solved by the invention]

Conventional vehicle electric motors are configured as described above, so heat loss due to the resistance of the winding on the stator side reduces efficiency, and in order to keep the temperature rise within limits, the conductor dimensions are increased and the current density is increased. Since it is necessary to lower the stator, there is a problem in that the stator is large and the electric motor is also large.

This invention was made in order to solve the above problems, and aims to provide a vehicle electric motor that reduces heat loss, improves efficiency, and can reduce the size of the stator.

[Means to solve the problem]

In the vehicle electric motor according to the present invention, the stator winding is a superconducting coil, and the stain current value is controlled by external excitation.

[Effect]

The vehicle electric motor of this invention uses a superconducting coil in the stator part, so there is no heat loss in this part, and only the heat loss in the external excitation circuit occurs, so the heat loss in the entire rounding is small and efficiency is improved. can be achieved. Furthermore, the superconducting coil allows a high current density, and the coil dimensions can be significantly reduced, making it possible to reduce the size and weight of the entire motor by downsizing the stator section.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, (2) is a superconducting coil, and (2) is a non-magnetic material tank that houses the superconducting coil (c).

In FIG. 2, 2) is a power source for energizing the superconducting coil 21), and 3) is a variable resistor for adjusting the current value.

Next, the operation will be explained. DC power source, variable resistor (
c) Since the superconducting coils (goods) are connected in series, the voltage E of the power supply (a) and the resistance value R of the variable resistor (goods)
, the current value r flowing through the superconducting coil (2) is determined. That is, equation (2) holds true.

In order to control the rotation &N of the electric motor, it is necessary to set the magnetic flux φ to vIIgl as described above, and the electric current must be adjusted from the relationship shown in FIG. In the excitation circuit shown in FIG. 2, the voltage EF of the power source is constant, and the stain resistance r can be adjusted by controlling the resistance value R of the variable resistor (c).

Current I when changing the resistance value of a variable resistor (goods),
The time constant of change τr is expressed by equation (3), where Lr is the inductance at the time of superconducting coil 3, and if the number of turns of the superconducting coil (b) is NF, to obtain the same ampere-turn, Time constant τr.

Resistor (c) heat loss W? and the number of turns N, is (4
) and (5), it is more effective to reduce the number of turns N.

τF QCl'i F -----------(4)
W, OCl/N, ---(5) FIGS. 3 and 4 show other embodiments of the present invention. In the figure, (2) is a short circuit switch for the closed Fjlr configuration, which is connected in parallel with the superconducting coil c2p and housed 58 in the tank (2).

In such a configuration, the permanent current mode is set by closing the voltage control head in the low speed range or the short circuit switch (to keep the output constant during constant speed driving in the high speed range). This eliminates loss due to heat generation, so that the efficiency of the negative layer can be improved.

〔Effect of the invention〕

As described above, according to this invention, since superconducting coils are used as the stator field windings, there is no heat loss in the field section, and the efficiency of the υ motor can be improved with only the external excitation circuit. effective. Furthermore, since the current density of the superconducting coil can be set high, the pinion can be made smaller, and the stator portion can be made smaller and the motor can be made smaller and lighter.

Furthermore, since the short-circuit switch can be used frequently in the persistent current mode, heat loss can be minimized to the minimum, and efficiency can be greatly improved.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view showing one embodiment of the present invention, FIG. 2 is a circuit configuration diagram of FIG. 1, FIG. 3 is a partial sectional view showing another embodiment of the invention, and FIG. Figure 3 is a circuit configuration diagram, Figure 5 is a plan view showing an example of the use of a vehicle electric motor, Figure 6 is a partial cross-sectional view of a conventional vehicle electric motor, and Figure 7 is a diagram showing the relationship between ampere turns of the stator and magnetic flux. FIG. In the figure, 3X) is a superconducting coil, (A) is a tank,
2) is the uI wire power source (c) is a variable resistor. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (2)

[Claims] (1) In a vehicle electric motor that drives a vehicle, the winding on the stator side is made of a superconducting material to form a superconducting coil and housed in a tank, and a DC power source and a variable resistor provided outside the tank are connected to the superconducting coil. A vehicle electric motor characterized by a coil connected in series. (2) In a vehicle electric motor that drives a vehicle, a superconducting coil is formed from a stator side winding using a superconducting material and is housed in a tank, and a short circuit switch housed in the tank is connected in parallel with the winding, A vehicle electric motor characterized in that a DC power source and a variable resistor provided outside the tank are connected in series to a parallel circuit of the winding and the short circuit switch.