【名词&注释】
熔断器(fuse)、表达式、热继电器(thermal relay)、相电流(phase current)、电流瞬时值(instantaneous current)
[单选题]三相对称电路中B相电流瞬时值(instantaneous current)为iB=sin(wt-30°)则A相电流瞬时值(instantaneous current)表达式为()。
A. iA=sin(wt-150°)
B. iA=sin(wt+90°)
C. iA=sin(wt+30°)
D. iA=sin(wt+60°)