Method and system for monitoring the condition of generator end windings

A system for monitoring the operating condition of an electric generator comprising a stator core including a plurality of stator bars located in circumferentially spaced relation to each other about a rotor, said system comprising:

• a fiber optic conductor;
• a plurality of triad sensor arrays formed in said fiber optic conductor, each said triad sensor array associated with one of the stator bars;
• each said triad sensor array comprising:
• a first sensor including a first Bragg grating for producing a base measurement signal indicative of a stress level in a stator bar of the generator;
• a second sensor including a second Bragg grating for producing an adjustment signal indicative of an adjustment to the base measurement and based on a measurement taken at the stator bar;
• and
• a third sensor including a third Bragg grating for producing a dynamic measurement signal of substantially cyclically varying value and indicative of a stress level in the stator bar;
• a source of optical radiation coupled to said fiber optic conductor for providing said first, second and third sensors of each said triad sensor array with optical radiation for producing said base measurement signal, said adjustment signal and said dynamic measurement signal;
• and
• an optical detector coupled to said fiber optic conductor for receiving said signals from said first, second and third sensors of each said triad sensor array, wherein said base measurement signal, said adjustment signal and said dynamic measurement signal are uniquely identified to said first, second and third sensors, respectively, of each said triad sensor array.

A system for monitoring the operating conditions of an electric generator, said system comprising:

• a triad sensor array formed within a predetermined section of a fiber optic conductor, said triad sensor array comprising a group of sensors including:
• a first sensor including a Bragg grating for producing a first signal representative of strain in a stator bar of the generator;
• a second sensor including a Bragg grating for producing a second signal representative of temperature in the stator bar;
• and
• a third sensor including a Bragg grating for producing a third signal representative of vibration amplitude in the stator bar;
• a source of optical radiation coupled to said fiber optic conductor for providing said first, second and third sensors with optical radiation for producing said first, second and third signals;
• and
• an optical detector coupled to said fiber optic conductor for receiving said first, second and third signals, wherein said first, second and third signals are uniquely identified to said first, second and third sensors, respectively.