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The main purpose of this thesis is to derive the mathematical
models of rectifier units in the AC/DC power systems and to
analyze the power system of mine, the DC electrified transit
railways, the HVDC transmission systems, and the power systems
of DC furnaces. First of all, rectifier units were divided
into controllable and uncontrollable, and classified as
6-pulse, 12-pulse, and 24-pulse. Then the characteristics of
various rectifier units were investigated under both three-
phase source voltage balance and imbalance conditions.
Furthermore, the mathematical models of controllable and
uncontrollable six-, twelve- and twenty-four-pulse rectifier
units were derived under three-phase source voltage balance
condition. Follows by controllable and uncontrollable six-pulse
rectifier units under three-phase source voltage imbalance
condition. Finally, the derived mathematical models were
implemented into a simple AC/DC power flow program which was
developed by Microsoft Visual Basic to study the performance of
AC/DC power systems with various pulse number and the effects
of voltage imbalance on the AC/DC power systems.
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