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Reverse reactive power protection (RQ)
2.29.2
The RQ function (RQ) consists of two stages (elements) independently (RQ1 and RQ2)
RQ1 element characteristic
(i)
Figure 2.29-4 shows the characteristic of the RQ1 element.
Determination of reactive power flow:
The user shall set a flow direction about reactive power, which the user can find the
corresponding information in Chapter
DEP, Lag, or Lead for setting [RQ-Power] to define the direction:
DEP:
Lag:
Lead:
Operation judgement of RQ element:
The RQ1 element can operate if the pick-up value of reactive power (Q) is less than
threshold setting [RQ1]. The RQ1 operation will return when the Q is greater than the
reset condition, at which the user can set with Equation (2.29-2):
Reset condition=setting [ RQ1 ] × setting[RQ1-DPR]
where,
RQ1:
RQ1-DEP:
Q(var)
0
Figure 2.29-4 Characteristic of RQ1 element
It can be agree with the Lag or Lead direction described with
the setting [Current] of
It cannot agree with the setting [Current]. The direction will
match with either positive or negative one defined by the
direction of Figure 9.2-4.a.
It cannot agree with the setting [Current]. The direction will
match with either positive or negative one defined with the
direction of Figure 9.2-4.b.
value of pick-up threshold in RQ1 element (var)
Ratio of prick-up and drop-off (%)
- 350 -
P(W)
Setting[RQ1]
Monitoring function
(cf. Chap. 9.2.4(ii)) Set either
Monitoring function
6F2T0207 (0.01)
.
(2.29-2)
GRE200 (5,6)
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