METHOD FOR LOOSE JOINT DETECTION IN MEDIUM VOLTAGE SWITCHGEARS AND MEDIUM VOLTAGE SWITCHGEAR ITSELF

• Main Authors: Magoni Stefano, Kozel Tomas, Scarpellini Massimo, Stupak Marcel
• Format: Patent
• Language: English
• Published: 25.05.2017
• Subjects: BOARDS, SUBSTATIONS, OR SWITCHING ARRANGEMENTS FOR THE SUPPLYOR DISTRIBUTION OF ELECTRIC POWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; GENERATION; INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASURING; PHYSICS; TESTING

A method for loose joint detection in medium voltage switchgears with busbar joints, circuit breaker upper and lower spouts, and cable connection joints, arranged in an air insulated housing, and medium voltage switchgear itself, in order to create an effective loose joint detection with lower operating expense, but with high performance and accuracy, involves measuring actual temperatures at a first phase as a first temperature (T1), at a second phase as a second temperature (T2), at a third phase as a third temperature (T3), at predefined critical points, such as at the busbar joints, and/or at the circuit breaker upper spouts, and/or at the circuit breaker lower spouts, and/or the cable connection; and comparing temperatures in a logical dependency Ti>(Tj+dT), with i≠j, permuted with i from 1, 2, 3, and j from 1, 2, 3, and setting the alarm if the logical dependency is fulfilled.