METHOD FOR DETECTING A STUCK AC SWITCH IN A CONVERTER

• Main Authors: LEGA, Marco, PAOLINI, Simone, MOTTA, Michele, RONDINE, Gianluca, BETTI, Giulio, ROMANO, Martino
• Format: Patent
• Language: English; French; German
• Published: 12.06.2024
• Subjects: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC,OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWERSUPPLY SYSTEMS; CONTROL OR REGULATION THEREOF; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUTPOWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; GENERATION; MEASURING; MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES; PHYSICS; TESTING

The invention relates to the field of converters, e.g. DC/AC or AC/DC converters, and particularly to a method for detecting a stuck AC switch (Sa1, Sb1, Sc1, San, Sbn, Scn) in a converter with a plurality of converter arrangements (10.1, 10.n), arranged in parallel. Each of the converter arrangements (10.1, 10.n) is configured for connecting to a DC source or DC load (20), and to a plurality of AC terminals (30). Each converter arrangement (10.1, 10.n) comprises a DC part (14.1, 14.n), with two capacitors (Cp1, Cn1), arranged in parallel to the DC source or DC load (20), and a neutral DC point (O1, On) between them. Further, each converter arrangement (10.1, 10.n) comprises a converter unit (12.1, 12.n) and at least one AC leg (a.1, b.1, c.1, a.n, b.n, c.n), each AC leg connected to a neutral AC point (N1, Nn) via an AC leg capacitor (Cfa1, Cfb1, Cfc1, Cfan, Cfbn, Cfcn). A pre-charge unit (40), arranged at each leg of the AC terminal (30). Between the neutral DC point (O1, On) and the neutral AC point (N1, Nn), a decoupling switch (So1, Son) is arranged. The method comprising the steps of:opening the second decoupling switch (Son) and all second AC switches (San, Sbn, Scn) of the second converter arrangement (10.n);loading the pre-charge unit (40);sequentially closing each second AC switch (San, Sbn, Scn) of the second converter arrangement (10.n);measuring, at each closing step, a voltage (Vabn, Vbcn, Vcan) between each AC leg (a.n, b.n, c.n) of the second converter arrangement (10.n); anddetermining the stuck AC switch (San, Sbn, Scn) of the second converter arrangement (10.n) based on the measured voltage (Vabn, Vbcn, Vcan).