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In-Depth Information
uL i
=
/
t
The factors Eq. (10) can be denoted by follows:
,
Ls
s
Ls
(
)
(
)
i
=
C du
/
dt
uL i
=
/
t
j
=
1, 2, 3, 5
i
=
C du
/
dt
j
=
1, 2, 3, 5
,
,
.
C
F
Lj
j
j
Cj
j
j
F
C
F
The correlation function of those factors in set
S
can be rewritten as
{
}
Ψ ii
=
,
,
i i
,
,
i
(11)
h
PPF
FC
TSC
Ls
There are following relationship in Eq.(11) ,
h
i
=+++
(12)
i
i
i
i
i
PPF
FC
TSC
Ls
i
PPF
=
(13)
{
}
(
) (
) (
) (
)
∈ + + + + +
(14)
Based on above analysis the maximum harmonic current that injected into the PPF,
FC, TSC can be obtained. For example the
i
and
Ls
i
i
,,,
i
i
i
i
,
i
i
,
i
i
,
i
i
i
TSC
1
2
3
1
2
2
3
1
3
1
2
3
i
can be described as follows
(
) (
)
i
=
ZZZ
//
//
/
ZZ Z Z i
+
+
+
(15)
5
Ls
Fc
TSC
Ls
Fc
TSC
PPF
h
(
) (
)
(16)
i
=
Z ZZ ZZZ Zi
//
//
/
+
+
+
Ls
PPF
Fc
TSC
Ls
Fc
TSC
PPF
h
Z
There
belong to following set
(
TSC
{
}
) (
) (
) (
)
(17)
Z
∈
Z
,
Z
,
Z
,
Z
+
Z
,
Z
+
Z
,
Z
+
Z
,
Z
+
Z
+
Z
TSC
TSC
1
TSC
2
TSC
3
TSC
1
TSC
2
TSC
2
TSC
3
TSC
1
TSC
3
TSC
1
TSC
2
TSC
3
Table 3.
parameters of a capacitor
capacitor (μF )
PPF
Capacity (kVar)
Connection mode
rated voltage (kV)
C
6.600/
3
300
2 series and 8 parallel
65.766
Table 4.
parameters of a reactor
PPF
rated voltage (kV)
fundamental voltage (V)
rated current (A)
reactor (mH)
L
6.600/
3
161.994
314.916
1.637
Considering different
TS
Z
the maximum
i
and
L
i
can be obtained. In order to
improve security it is not necessary to take the resonance point is 4.85. Following
parameters such as
(
) (
)
=
can be calculated. Giving attention to
evidently decrease the cost and analyze parallel resonance of every combination of
Table 2, the parameters of the PPF was derived in Table 3 and Table 4.
LCC
,,
i
, , ,5
i
i
F
4
Actual Measurement Results Analysis
The device that consists of PPF, FC and TSC has been serviced in a coal mine of
northern China since November 24
th
2009. Figure6 to Figure9 show the result that
obtained by proposed device. Figure6, Figure7 and Table 5 show that the 5
th
, 7
th
, 11
th
and 13
th
harmonic current was reduced significantly and far less than the national
standard GB/T-14549-93. Compare Figure6 to Figure7 denotes that the 7
th
harmonic
current was magnified by the action of FC and TSC only. Figure 7 indicates that the
resonance of 7
th
harmonic current, i.e. the negative effect of the TSC was suppressed
by PPF.
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