单相设备对三相四线系统零线的影响和对策

The Influences of Single-phase Equipment on the Three-phase Four-wire System Zero Line and its Countermeasures

生产现场的供配电系统通常按照三相平衡负载设置,当运行中的供配电系统不平衡加入大功率单相设备时,必须校验原系统的零线截面是否满足载流量的要求。通过生产实例说明了TN-C系统中零线传导三相系统中不平衡电流和单相电流、减少中性点的电压偏移的作用,指出了合理选择TN-C系统零线的方法。

The power supply system in the working site is ordinarily set up according to three-phase balance load and when the imbalanced power single-phase equipment is connected with the operating power supply system,the zero line surface of the original system must be inspected that if it meets the needs of the load.The cases are analyzed to demonstrate the functions of the imbalanced current, single-phase current and voltage deviation reduction in TN-C power supply system.The methods to reasonably select TN-C system zero line are put forward.