Because the clamp effect of DC voltage source, AC side output the rectangular wave voltage waveform, and it has nothing to do with the load impedance Angle.
由于直流电压源的钳位作用，交流侧输出电压波形为矩形波，并且与负载阻抗角无关。
2
To guarantee the reliability and security of the steel construction, the clampload of the joint bolt should be under strict control, sometimes even the tension of the bolt should be measured on-line.