DE198954C - - Google Patents

Description

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IMPERIAL

PATENT OFFICE.

PATENT LETTERING

- JVl 198954 CLASS 21 r /. GROUP

Patented in the German Empire on June 9, 1907.

The purpose of the present invention is to improve the power consumption of a converter through its Conveying a work machine with strongly changing load is driven within to keep certain limits.

For a more detailed explanation of the invention, the example of an electrically operated hoisting machine is to serve, whose motor m by a converter for three-phase direct current

ιό or direct current direct current is fed; α is the motor, g the generator of the converter, e the exciter.

Normally, such converters are equipped with centrifugal masses s , through the effect of which the current consumption of the converter motor does not exceed a certain amount as long as the slip control device still leads to a reduction in the number of revolutions of the converter during the period of maximum load. The slip control device consists, for example, of a water resistance w, the movable electrodes of which are raised or lowered by the so-called slip control motor f; the latter is fed by the transformer t with a current which is proportional to that of the motor α. If the lower limit of the number of revolutions allowed by the slip regulator is reached and the maximum load on the conveyor motor is still present, the current to be absorbed by the converter motor must naturally exceed the normal level.

If the flywheel is uncoupled from the converter by the releasable coupling k or if no flywheel is provided for the converter at all, the load on the converter motor is directly dependent on that of the conveyor motor, so that if the conveyor motor is overloaded, the converter motor must also be overloaded.

In order to prevent this, regardless of whether a flywheel is present or not, a device is provided according to the invention, independently of the slip regulator, but designed in a similar way, which depends on the current flowing to the converter and, when this has reached a certain level, a normally short-circuited resistor is gradually connected upstream of the field of the starting machine g. This reduces the voltage of the starting machine and thus also the number of revolutions of the conveyor motor and the conveyor speed. The delivery rate and, depending on this, the power output and power consumption of the converter motor are influenced by this arrangement in such a way that the power supply of the converter motor does not exceed a certain maximum. The device mentioned can for example consist of a water resistance jv ¹ with motor / ¹ and transformer i ¹ , similar to the slip control device.

You can z. B. achieve that when the centrifugal masses during larger Operating periods in which there is not normal delivery to reduce friction losses are uncoupled, but also during these periods immediately if necessary any loads can be conveyed without the current consumption of the mo-

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Claims (1)

tors too high. In contrast to a known device, in which the field of the starting machine when uncoupling the centrifugal masses an invariable one Resistor is connected upstream, an automatic speed control takes place, by conveying larger loads at a slower speed, while smaller ones are with the same which normal through ίο the control lever h is adjusted. The machinist can also be promoted without a flywheel and z. B. full payload, as usual, fully interpret the control lever, and yet the conveying speed only comes to a part of its full value, which corresponds to the permitted energy consumption from the control center. Smaller loads (e.g. people) can, however, be conveyed at full speed (speed of the cable car). During the time when the flywheel is coupled to the converter, the control device described can be rendered ineffective by setting it to a slightly higher current than the slip regulator, if excessive discharge of the flywheel mass is not to be feared, by turning the Motor / ¹ switches off or transformer i ^{1 is} short-circuited. The switch c used for this purpose can be locked mechanically or electrically with the release device of the clutch k ^{so that the motor / 1 is} automatically switched on when the flywheel is uncoupled. The slip control motor f or transformer t is turned off or short-circuited when the centrifugal masses are uncoupled, so that the three-phase motor α runs at maximum speed and without any loss of resistance. As mentioned, the new control device can also be used when the Flywheels are missing or, if in a known way, a buffer battery to compensate for the load serves, which at times of low energy consumption by one with the Starting machine seated on the same shaft and shared with it by one Steam engine driven power generator is charged, however, when there is a large energy demand drives the latter as a motor. The control device protects the battery from excessive discharge currents. the The magnetic device acting on the control resistor must be placed in the discharge circuit be switched. Patent-A ν SPRU ch: Device to limit the current Recording of converters, which work machines with strongly changing loads feed and run at least temporarily without centrifugal masses, by switching on a resistance in the field circuit the starting machine, characterized in that this resistance is independent of the existing slip regulator a similarly designed current flowing to the converter influenced apparatus is automatically regulated in such a way that while limiting the Energy and therefore current consumption of the converter motor to a permissible value, heavy loads only slowly, smaller ones On the other hand, loads can be transported faster. For this purpose ι sheet of drawings.