Null sequence polygon relay based on null sequence reactor
A zero-sequence reactance and relay technology, applied in the field of power systems, can solve problems such as longitudinal zero-sequence directional protection misoperation
Active Publication Date: 2010-09-22
BEIJING SIFANG JIBAO AUTOMATION +1
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When a ground fault occurs on these mutual inductance lines, the zero-sequence directional elements of the non-fault line are affected by the zero-sequence mutual inductance. The most serious situation is that the zero-sequence directional elements on both sides of the line are judged as Malfunction of longitudinal zero-sequence directional protection due to positive direction
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[0022] The technical solution of the present invention will be further described in detail according to the accompanying drawings.
[0023] figure 1 Shown is a schematic diagram of the action characteristics of the zero-sequence reactance polygonal relay installed on the sending end on the impedance plane, figure 2 It is a schematic diagram of the action characteristics of the zero-sequence reactance polygonal relay installed on the receiving end on the impedance plane. In the figure, L1 and L2 correspond to criterion formula (1) and formula (2) respectively. MN is the positive sequence impedance of the protected line.
[0024] Select the setting impedance Z according to 1.1 to 1.3 times the positive sequence impedance of the line set1 , and select the matching amplitude greater than the difference between the set impedance and the positive sequence impedance of the line, that is, 0.1 to 0.3 times the positive sequence impedance of the line, and the set impedance Z whose ph...
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The invention relates to an impedance relay of relay protection in the field of electrical systems, which provides a zero-sequence reactance polygonal relay based on zero-sequence reactance lines. A setting impedance is chosen according to a certain multiple of a positive sequence impedance, in addition, a setting impedance whose phase difference with a circuit positive sequence impedance is 180 degrees is chosen, and therefore, the offset voltage of two setting impedances with zero-sequence current compensation is calculated out according to phases, and phase comparison equations of two zero-sequence reactance lines are respectively established through utilizing zero-sequence current or zero-sequence offset voltage to be polarized amount. A zero-sequence reactance polygonal relay is formed through choosing a correct margin angle of a reactance line. The zero-sequence reactance polygonal relay is adopted to judge fault directions in high-voltage line protection.
Description
technical field [0001] The invention relates to the field of electric power system, and more particularly relates to a design method of an impedance relay for relay protection of electric power system. Background technique [0002] With the expansion of the scale of my country's power grid and the construction of various large-scale power projects, parallel double-circuit or multi-circuit lines of the same voltage level or even different voltage levels are often erected in high-voltage and ultra-high-voltage transmission corridors, as well as whole or part of the same pole lines. The mutual inductance between lines presents diversity and complexity. When a ground fault occurs on these mutual inductance lines, the zero-sequence directional elements of the non-fault line are affected by the zero-sequence mutual inductance. The most serious situation is that the zero-sequence directional elements on both sides of the line are judged as The positive direction causes the misopera...
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IPC IPC(8): H02H7/26
Inventor 黄少锋刘千宽张月品徐振宇
Owner BEIJING SIFANG JIBAO AUTOMATION