Patent ID: 6992907

Claim:
An AC-AC wave transformation device comprising: n transformation modules; the input terminals of each of these transformation modules are connected to n groups of m phase AC that are insulated from each other; the output terminals of these transformation modules are connected in series to obtain a total voltage output; wherein each transformation module includes power semiconductor switching components or power semiconductor switching component groups, the power semiconductor switching components or power semiconductor switching component groups are connected to form a full-wave bi-directionally controlled m phase rectifying circuit, the output polarity of said full-wave bi-directionally controlled m phase rectifying circuit is variable; and said full-wave bi-directionally controlled m phase rectifying circuit includes 2×m power semiconductor switching components or power semiconductor switching component groups, each of the power semiconductor switching component or power semiconductor switching component group is connected respectively between m input lines and two output lines; the power semiconductor switching component is a bi-directional thyristor.