Power converter control method

A power converter control method of controlling a direct AC-AC power converter which comprises:

• a rectifier circuit which inputs first AC voltages and outputs a rectified voltage;
• and a voltage source inverter which inputs said rectified voltage, applies three-phase second AC voltages to a load, and outputs three-phase load currents to said load, wherein
• a modulation factor of said voltage source inverter includes a DC component and an AC component which is an angular frequency which is a 6n multiple (n is a natural number) of a base fundamental angular frequency of said second AC voltage, and
• when a fundamental wave component, a (6n−1)th order component and a (6n+1)th order component of said load current are Iu1, Iu6n−1 and Iu6n+1, respectively, and phase differences of said fundamental wave component, said (6n−1)th order component and said (6n+1)th order component of said load current from a fundamental wave component of said second AC voltage are φ1, φ6n−1 and φ6n+1, respectively,
• a ratio of an amplitude of said AC component with respect to said DC component takes a ratio represented by
• −[m6n2+Iuh6n2+2·m6n·Iuh6n cos(θ−χ6n)]1/2/[Iu1·cos(φ1)]
• [m6n=[Iu6n−12+Iu6n+12+2·Iu6n−1·Iu6n+1·cos(φ6n−1−φ6n+1)]1/2), and
• a phase difference (φ6n) of said AC component from the fundamental wave component of said second AC voltage takes an angle represented by
• tan−1[{m6n·sin(χ6n)+Iuh6n·sin(χ6n)}/{m6n·cos(χ6n)+Iuh6n·cos(χ6n)}]
• (χ6n=tan−1[{Iu6n−1·sin(φ6n−1)+Iu6n+1·sin(φ6n+1)}/{Iu6n−1·cos(φ6n−1)+Iu6n+1·cos(φ6n+1)}],
• with relationship of Iuh6n<m6n and θ:
• arbitrary.

A power converter control method of controlling a direct AC-AC power converter which comprises:

• a rectifier circuit which inputs first AC voltages and outputs a rectified voltage;
• and a voltage source inverter which inputs said rectified voltage, applies three-phase second AC voltages to a load, and outputs three-phase load currents to said load, wherein
• a voltage command to said voltage source inverter includes a DC component and an AC component of an angular frequency which is a 6n multiple (n is a natural number) of a base fundamental angular frequency of said second AC voltage, and
• when a fundamental wave component, a (6n−1)th order component and a (6n+1)th order component of said load current are Iu1, Iu6n−1 and Iu6n+1, respectively, and phase differences of said fundamental wave component, said (6n−1)th order component and said (6n+1)th order component of said load current from a fundamental wave component of said second AC voltage are φ1, φ6n−1 and φ6n+1, respectively,
• a ratio of an amplitude of said AC component with respect to said DC component takes a ratio represented by
• −[m6n2+Iuh6n2+2·m6n·Iuh6n cos(θ−χ6n)]1/2/[Iu1·cos(φ1)]
• [m6n=[Iu6n−12+Iu6n+12+2·Iu6n−1·Iu6n+1·cos(φ6n−1−φ6n+1)]1/2), and
• a phase difference (φ6n) of said AC component from the fundamental wave component of said second AC voltage takes an angle represented by
• tan−1[{m6n·sin(χ6n)+Iuh6n·sin(χ6n)}/{m6n·cos(χ6n)+Iuh6n·cos(χ6n)}]
• (χ6n=tan−1[{Iu6n−1·sin(φ6n−1)+Iu6n+1·sin(φ6n+1)}/{Iu6n−1·cos(φ6n−1)+Iu6n+1·cos(φ6n+1)}]
• with relationship of Iuh6n<m6n and θ:
• arbitrary.