Novel analysis methodology of differential protection operation behavior: Part two Analysis

作者：Lin Xiangning^*; Liu Pei; Xu Tao

来源：Automation of Electric Power Systems, 2003, 27(24): 32-36+62.

• Current transformer saturation
• Differential protection
• Light internal faults
• Product constraint
• Through current
• Transferring ratio

Based on the new methodology to analyze the operating behavior of the differential protection, which is proposed in the Part One, both the abilities immune to the current transformer saturation and the sensitivities of these two novel product restraint criteria are investigated with respect to the change of the settings in the percentage differential characteristic plane. It is proved that each parameter of the percentage differential characteristics can be adjusted as required. In this way, the operating point which is most possibly subject to the mal-operation can be configured to the one at which the current transformer has the least transferring error. Meanwhile, the fail-to-trip area should be arranged to the operation conditions which impossibly or rarely occur. With this arrangement, the advantages of the criteria can be highlighted and the disadvantages can be avoided. On the basis of comparative analysis, these two criteria have identical security in the condition of the current transformer saturation. However, the one with conditional operation area has higher sensitivity and flexibility in the occasion of light internal faults, which is hence slightly better than that using restraint area.

• 出版日期2003