Electrical partial discharge pulse marker discrimination

In a system comprising an electrical generator connected to a step-up transformer by a conductor comprising a plurality of isophase buses, and a monitor comprising a plurality of first modules connected to respective isophase buses adjacent to the generator and an analyzer unit including one or more second modules connected to the isophase buses adjacent to the step-up transformer, a method for detecting partial discharge pulses emanating from the generator, the method comprising the steps of;

• detecting one or more partial discharge pulses at respective first modules;
• detecting the one or more partial discharge pulses at the analyzer unit;
• generating a marker pulse for each of the one or more partial discharge pulses at the respective first modules;
• detecting each marker pulse at the analyzer unit;
• for each marker pulse, determining a differential value corresponding to a difference between a time of arrival of the partial discharge pulse at the analyzer unit and a time of arrival of a corresponding marker pulse at the analyzer unit;
• and
• using each differential value to identify whether a corresponding partial discharge pulse originated at the generator and to identify the isophase bus associated with the corresponding partial discharge pulse.

In combination with a system comprising an electrical generator connected to a step-up transformer by a conductor comprising a plurality of isophase buses, a monitor for detecting partial discharge pulses emanating from the generator, the monitor comprising:

• a plurality of first modules connected to respective isophase buses adjacent to the generator, each of the first modules generating a marker pulse in response to a partial discharge pulse;
• an analyzer unit including one or more second modules connected to the isophase buses adjacent to the step-up transformer;
• and
• wherein the analyzer unit receives each partial discharge pulse and each marker pulse and determines a differential value corresponding to a difference between a time of arrival of a partial discharge pulse and a time of arrival of a corresponding marker pulse to identify a partial discharge pulse originating at the generator and to identify the isophase bus associated with the corresponding partial discharge pulse.