Real time live line measurement of metrological properties of current transformers

An electrical measurement apparatus for online live line analysis of metrological properties of a current transformer, the apparatus comprising:

• a primary sensing module comprising:
• a primary sensor configured to measure a primary current in a primary conductor of a current transformer in order to obtain a series of primary current data points;
• and
• a primary global navigation satellite system (GNSS) signal receiver configured to attribute a primary GNSS time stamp to each one of the series of primary current data points to obtain a primary series of time stamped data points;
• and
• a secondary sensing module comprising:
• a secondary sensor configured to measure a secondary current in a secondary conductor of the current transformer in order to obtain a series of secondary current data points;
• and
• a secondary GNSS signal receiver configured to attribute a secondary GNSS time stamp to each one of the series of secondary current data points to obtain a secondary series of time stamped data points;
• wherein the primary sensing module is configured to transmit the primary series of time stamped data points to the secondary sensing module;
• and
• wherein the secondary sensing module is configured:
• to receive the primary series of time stamped data points;
• to generate aggregated data comprising both the primary series of time-stamped data points and the secondary series of time-stamped current data points;
• and
• to output the aggregated data.

A measuring head for measuring an electrical property of a conductor, comprising:

• a sensor configured to measure the electrical property;
• an upper jaw;
• a lower jaw;
• a mechanism for opening and closing the upper and lower jaws;
• a first connecting element configured for connecting a rotatable rod;
• a second connecting element configured for connecting a non-rotatable rod;
• wherein the upper and lower jaws are configured to grasp the conductor in a closed position and to release the conductor in an open position;
• and
• wherein the opening and closing of the jaws is actuated by rotation of the rotatable rod, and
• wherein the measuring head further comprises electro-magnetic shielding to enable hot stick mounting on an energized power line conductor on a high voltage side of current transformer under test.