Start-up control loop for DC lubricating oil pump in steam turbine unit

Abstract

The invention provides a start control loop specific to a direct current lubricating oil pump in a turboset. A control loop comprises a signal switch and two contactors. A start loop comprises two normally open contacts. The signal switch is connected with one ends of the two contactors. The other end of the signal switch and the other ends of the two contactors are connected with an anode and a cathode of a first direct current power source correspondingly. An anode of a second direct current power source is connected with circuits where the two normally open contacts are located. The circuitwhere the first normally open contact is located and the circuit connected with a cathode of the second direct current power source form an excitation loop. The circuit where the second normally opencontact is located and the circuit connected with the cathode of the second direct current power source form an armature loop. Under control of an external control signal, the signal switch is switched off, the first contactor and the second contactor are electrified, the first normally open contact and the second normally open contact are switched off, the excitation loop and the armature loop are connected, a motor is started, and the direct current lubricating oil pump is started. Through the scheme, the direct current lubricating oil pump can be fast started on the premise that the safetyof the motor is ensured.

Description

technical field [0001] The invention relates to the technical field of steam turbine control, in particular to a start-up control circuit for a DC lubricating oil pump in a steam turbine unit. Background technique [0002] The stability of the lubricating oil pressure of the steam turbine is a necessary condition to ensure the safe operation of the steam turbine, and the DC lubricating oil pump plays an important role in the lubricating oil system as a backup oil pump. When the oil pump is not connected, or the AC power supply is lost in the electrical aspect, when the AC oil pump cannot be put into operation, the DC lubricating oil pump cannot start quickly and supply oil normally, which will cause accidents such as oil cut-off and tile burning, so it can provide a reliable and stable The start-up control method of DC lubricating oil pump is the key factor to solve such problems. At present, different DC lubricating oil pumps have their own start-up control methods. For ex...

AI Technical Summary

Problems solved by technology

[0003] The embodiment of the present invention provides a start-up control circuit for the DC lubricating oil pump in the steam turbine unit, which can quickly start the DC lubricating oil pump under the premise of ensuring the safety of the motor, and solves the problem of unreliable starting pressure of the DC lubricating oil pump during the operation of the steam turbine unit

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