Overhead Ground Wires Induction Current and Energy Loss of 220 kV Double Circuit Transmission Lines

In the case that overhead ground wires of double circuit transmission lines are grounded at each tower,the induction current and energy loss in overhead ground is a problem which is of less quantitative researches currently.The overhead ground wire induction current of a 220 kV double circuit transmission line at Guangdong is measured in the field,and simulation calculation is carried out using ATP-EMTP,where measured results of are well accord with the calculated values.The effect of factors such as phase sequence arrangement, line current and line current unbalanced degree on ground wire induction current and energy loss are also discussed.The results show that induction current and power loss is the minimum value in reverse phase sequence arrangement of double circuit transmission lines.It appears a linear relationship between the overhead ground wire induction current and line current,while energy loss of the overhead ground wires increases in square form with the circuit current increasing.As line current unbalanced degree increases,the overhead ground wire induction current and energy loss increase,which requires strictly limit to the current unbalanced degree.