-0H~0~^0^, H~0~^0^, H~0~^0^, H~0~^0^0H~0~^0^, H~0~^0^, H~0~^0^, H~0~^0^-0H~0~^0^, H~0~^0^, H~0~^0^, H~0~^0^0H~0~^0^, H~0~^0^, H~0~^0^, H~0~^0^0Figure 0(a). quasi-sinusoidal voltage in symmetrical operation with respect to k = 0 and n = 0. 