Electronic liquid level sensing device and gauge for liquid-immersed power transformers, reactors and similar equipment

摘要

The present invention is a unique system for liquid-immersed transformers and reactors with complex internal thermal gradients that provides telemetry on multiple transformer or reactor conditions including: the level and volume of the liquid, the integrity of the winding clamping, the overall tank pressure, the gas pressure for gas blanketed transformers, and the condition of the breather for conservator type transformers or reactors, and the impacts from ballistics on the tank or cooling system. The present invention can be used on conservator type or gas blanketed type transformers. The liquid level can be calculated at any level in the transformer or reactor by the location of the oil pressure sensor at the bottom of the tank. The method for calculating liquid level does not require liquid temperature measurement. Average liquid temperature is calculated rather than estimated from discrete measurements, providing accurate average temperature values under all operating conditions.

主权项

1. A process for determining a liquid oil level in a liquid-immersed power transformer without using a mechanical float or a mechanical oil level gauge, the process comprising the steps of:
measuring an oil pressure at a bottom of the transformer oil filled tank; measuring a gas pressure above the oil in the transformer oil filled tank; calculate a liquid oil volume in the transformer oil filled tank using the measured oil pressure at the bottom of the tank and the measured gas pressure above the oil in the tank; and, calculate a liquid level of oil in the transformer oil filled tank.