SU106948A1 - Dynamic braking method of DC motor - Google Patents

Description

This invention relates to methods for dynamically braking a direct current motor fed from a controlled mercury rectifier, implying that a common load resistance is connected to the motor pole and the mercury rectifier and automatically adjust the braking torque of the motor by changing the voltage of the direct voltage.

When braking is realized, according to a well-known method, the brake torque is not constant and decreases with a decrease in the current in the engine cortex at C 1 the rotation speed of the latter.

The proposed braking method allows the braking torque to be kept constant.

This is achieved by changing the voltage of the rectifier depending on the current of the engine using the same scheme; and the maximum and minimum values of the motor current, acting on a circuit on the equipment of the net uirav.chpi rectifier.

The drawing shows a diagram of an apparatus for carrying out braking according to the previous method.

Parallel; motor koryu motor. L D included braking resistance RT and normally open contact of the dynamic deceleration contactor DG. The control of mercury rectifier cells is performed with POMOPYOF of the FS phase displacement unit, which is affected by the output of the magnetic amplifier M (The diagram shows only the winding of the magnetic amplifier performing the current cut-off. The remaining windings of the amplifier are not shown in the diagram). In order to reduce the speed of the operating drive, open the MU control winding circuit (not shown on cxeFvie) and turn on the deceleration deceleration contactor. At the first moment, the rectifier will be locked and the current Id will disappear. The engine will then switch to the dynamic braking mode, i.e. it will send a current of 1 l to the braking circuit RT. However, current 1; (will not be able to exceed current limiting circuit settings (usually double rated motor current -2l; ii) because as soon as it reaches this value, a current whose direction corresponds to the opening of the rectifier is used in the winding of the current limiting MU. causing the Koirrype to decelerate RT is the current from v; the mm / fd displaces part of the current 1e and keeps its value at the installation level. This current component can be called the back pressure current.