function a = init(a)a.con = [];a.n = 0;a.syn = [];a.bus = [];a.vbus = [];a.vref = [];a.vref0 = [];a.vr1  = [];a.vr2 = [];a.vr3 = [];a.vfd = [];a.vm = [];a.vf = [];a.u = [];a.store = [];