Sensor for transformer condition assessment

A sensor assembly for monitoring an internal condition of a transformer comprising:

• a body for location outside a tank of the transformer, the body housing an electronics assembly including body sensors coupled to a processor, wherein the body sensors include a vibration sensor and an acoustic sensor;
• a probe including an elongate tube extending from the body for insertion into a tank of the transformer;
• a plurality of probe sensors coupled to the processor disposed at or toward a remote end of the elongate tube for sensing conditions within the tank;
• wherein the processor is configured to process signals from the probe sensors and the body sensors to produce signals for assessing one or more of:
• transformer core temperature;
• transformer insulation state;
• partial discharge;
• mechanical state of transformer;
• chemical state of transformer, wherein:
• the vibration sensor and the acoustic sensor comprise an accelerometer configured to measure vibration from the tank from sub hertz frequencies up to audible frequencies above 1000 Hz;
• and/or,
• one of the body sensors comprises a magnetic field sensor for sensing magnetic fields associated with operation of the transformer, wherein
• the plurality of probe sensors includes a probe antenna for detecting EM radiation associated with partial discharge, and wherein the processor is configured to correlate signals corresponding to the probe antenna and the magnetic field sensor to detect partial discharges occurring during operation of the transformer.

A method for assessing an internal condition of a transformer by use of a sensor assembly for monitoring an internal condition of a transformer comprising:

• a body for location outside a tank of the transformer, the body housing an electronics assembly including body sensors coupled to a processor;
• a probe including an elongate tube extending from the body for insertion into a tank of the transformer;
• a plurality of probe sensors coupled to the processor disposed at or toward a remote end of the elongate tube for sensing conditions within the tank;
• wherein the processor is configured to process signals from the probe sensors and the body sensors to produce signals for assessing one or more of:
• transformer core temperature;
• transformer insulation state;
• partial discharge;
• mechanical state of transformer;
• chemical state of transformer, the method comprising:
• inserting the elongate tube into the tank of the transformer to thereby install the plurality of probe sensors as a plurality of internal sensors within the transformer;
• installing the body of the sensor assembly outside of the transformer, the body sensors comprising external sensors adjacent an outside surface of the transformer;
• monitoring signals from the internal sensors and the external sensors including sampling the signals simultaneously;
• and
• making an assessment of the internal condition of the transformer based on a correlation of all of the signals sampled simultaneously.

A sensor assembly for monitoring an internal condition of a transformer comprising:

• a body for location outside a tank of the transformer, the body housing an electronics assembly including body sensors coupled to a processor;
• a probe including an elongate tube extending from the body for insertion into a tank of the transformer;
• a plurality of probe sensors coupled to the processor disposed at or toward a remote end of the elongate tube for sensing conditions within the tank;
• wherein the processor is configured to process signals from the probe sensors and the body sensors to produce signals for assessing one or more of:
• transformer core temperature;
• transformer insulation state;
• partial discharge;
• mechanical state of transformer;
• chemical state of transformer, wherein the electronics assembly includes at least one magnetic field sensor coupled to the processor, and wherein the plurality of probe sensors includes a probe antenna for detecting EM radiation associated with partial discharge, wherein the processor is configured to correlate signals corresponding to the probe antenna and the magnetic field sensor to detect partial discharges occurring during operation of the transformer.

A sensor assembly system for monitoring an internal condition of a transformer comprising:

• a body for location outside a tank of the transformer, the body housing an electronics assembly including body sensors coupled to a processor;
• a probe including an elongate tube extending from the body for insertion into a tank of the transformer;
• a plurality of probe sensors coupled to the processor disposed at or toward a remote end of the elongate tube for sensing conditions within the tank;
• including a remote temperature sensor for sensing a temperature at a location on the transformer tank in combination with a remote server;
• wherein the processor is configured to process signals from the probe sensors and the body sensors to produce signals for assessing one or more of:
• transformer core temperature;
• transformer insulation state;
• partial discharge;
• mechanical state of transformer;
• chemical state of transformer, and
• wherein the processor and/or the remote server are configured to:
• determine a transformer load condition taking into account signals from the oil temperature sensor and the body temperature sensor,
• take into account signals from the oil temperature sensor, the remote temperature sensor and the body temperature sensor and the magnetic field sensor for determining a load of the transformer;
• and/or
• produce a signal indicating core temperature of the transformer taking into account signals from at least the oil temperature sensor and the body temperature sensor;
• and/or
• produce a signal indicating core temperature of the transformer taking into account signals from the oil temperature sensor, the body temperature sensor and the remote temperature sensor.