| 摘要 |
PROBLEM TO BE SOLVED: To reduce the power loss in a zero voltage circuit, by controlling the initial current to a reactor for resonance according to the output current detected by a detecting means. SOLUTION: A power converter 10 is composed of an inverter circuit 3 for converting DC power into AC power synchronous with a system power supply, a zero voltage circuit 2 for turning the input voltage to zero voltage at the time of switching, a controller 11 for controlling the zero voltage circuit 2 and the inverter circuit 3 through a first and a second drivers 7, 8, and a current sensor 12 for detecting the output current of the inverter circuit 3. Here, the initial current IL0 to a reactor L for resonance when resonance of the zero voltage circuit 2 starts is controlled so as to satisfy a following expression, IL0 =k.Is+I0 (k is a factor, about 1.5), where Is is the output current of the inverter circuit and I0 is the initial current required for exciting the reactor for resonance at no-load. By this method, noise and loss due to a switching can be reduced. |
