Voltages, Currents and Structures of the Thyristor Valve Blocks of a Controllable Reactor of Transformer Type

As a high-power and multi-winding electric power equipment, the winding grading standard and the structures of thyristor valve blocks series with control windings, greatly affect the design and control complexity of a controllable reactor of transformer type (CRT). First, the equivalent circuit converted to the work winding of a CRT is established. According to the harmonic requirements in a grid, the branch currents are calculated in three kinds of single branch operation modes by using the winding grading standard based on the harmonic current value, root mean square. Second, the voltages of thyristor valve blocks are calculated under the assumption that the currents of the thyristor valve blocks are variables for an integer multiple value of the maximum of branch currents. And then, the structures of the thyristor valve blocks are determined. Finally, the calculated results in the example show that the assumption of the currents of the thyristor valve blocks is reasonable. At the same time, though the number of control windings of a CRT and the integer multiple of the maximum current are the same, the structures of the thyristor valve blocks are variable with different operation modes and relatively simpler in the step-single-branch operation mode.