| 摘要 |
A three phase, three wire voltage stabilizer regulates an unregulated 3 phase AC source to a regulated three phase AC output. The regulator consists of a buck-boost transformer primary PR, PY, PB, connected in delta format and three isolated secondary windings SR, SY, SB, each connected in series with each phase of the input R1, Y1, B1, to provide a regulated output R2, Y2, B2. An IGBT based power stage consists of half bridge IGBT modules Q1-Q12 in anti-series connection from each input phase. The output of the IGBT half bridge modules feeds the primary of the buck-boost transformer through high frequency inductors L1-L6. Across each primary winding capacitors C4, C5, C6, and metal oxide varistors (MOV) M1, M2, M3, are connected. A control circuit is provided to sense the input voltages, output voltages and output current and give the required PWM drive signals to the switches. The half-bridge modules may be replaced with full-bridge modules. |
