Power supply fluctuation delay control circuit for coal feeder

Abstract

The invention discloses a power supply fluctuation time-delay control circuit for a coal feeder. The power supply fluctuation time-delay control circuit comprises a starting switch, a control relay connected with the starting switch in series, a time-delay relay connected with the control relay in parallel and a stop switch connected with the starting switch in series, wherein the control relay isprovided with a first switch connected with the starting switch in parallel and a second switch connected with the time delay relay in series, and the second switch is connected with the time delay relay in series; and the time-delay relay is a power-off time-delay relay and is provided with a third switch which is connected with the starting switch and the first switch in parallel, and the thirdswitch is connected with the second switch in series. By additionally arranging the power-off time-delay relay, when the power supply of the coal feeder fluctuates and the coal feeder control relay loses power to cause tripping of the coal feeder, the power supply returns to normal at the time when the third switch is switched off in a time-delay mode, and the relay is controlled to be rapidly powered on, so as to guarantee that the coal feeder can be rapidly and automatically started.

Description

Technical field [0001] The invention relates to the field of time delay control circuits, in particular to a power source fluctuation time delay control circuit for coal feeders. Background technique [0002] For thermal power generating units, when the grid line fails, the factory equipment or electrical circuit fails, and the large auxiliary equipment starts, the factory bus voltage may be pulled down. In order to prevent the abnormal drop of the bus voltage, the auxiliary equipment such as the coal feeder may be frequency-converted The coal feeder has been out of service, and the thermal power unit has successively carried out the low-voltage ride-through transformation of the coal feeder. The transformation is mainly aimed at the reliable power supply of the coal feeder inverter when the power supply voltage of the coal feeder drops to ensure the safe operation of the coal feeder, but the reformation did not optimize the coal feeder relay control loop. The coal feeder contro...

AI Technical Summary

Problems solved by technology

From the trip of the coal feeder to the discovery of the problem by the operator, and then resending the start command, it will inevitably delay a long time, and if the coal machine cannot resume operation quickly after the trip, it will have a great impact on the combustion of the boiler. even cause the unit to shut down

Images