Page 172 - Decision Making Applications in Modern Power Systems

136 Decision Making Applications in Modern Power Systems

TABLE 5.1 System loads of the 13-bus test feeder.
Phases

Bus Model 1 kW 1 kVAr 2 kW 2 kVAr 3 kW 3 kVAr
634-2 PQ 160 110 120 90 120 90
645-2 PQ 0 0 170 125 0 0
646-2 PQ 0 0 0 0 230 112
652-2 Z 128 86 0 0 0 0
671-2 PQ 333 153 333 153 333 153
675-2 PQ 265 100 268 150 260 112
692-2 I 170 110 0 0 0 0
611-2 I 0 0 0 0 170 80
680-2 PQ 66 39 66 39 66 39
Sum 1122 598 957 557 1179 586

Figs. 5.10 and 5.11 show the voltage in the phases along the feeder with-
out the insertion of PV’s and with 100% penetration at 12 a.m.
The full, dotted, star represent phases one, two, and three, respectively.
As can be seen in Fig. 5.11, voltage on phase 3 was impaired with the
insertion of the PVs due to the reverse power flow generated in the system.
The limit proposed by IEEE 1547 standard is exceeded at certain times of
day discussed.
Fig. 5.12 represents the single-phase voltage of phase 3 of the single-
phase bus 611 for the cases without PV penetration and with penetration of
PVs at the different levels as previously described. Note that conventional
tap control at the substation is unable to correct the voltage problem for
this case.

5.4.1.2 Simulation of smart controls
To mitigate the overvoltage problem caused by the high penetration of PVs
in the grid, the Volt/Var control is applied to the single-phase inverter of
611-bus. The voltage versus Vars curve created in the OpenDSS through
the VVcontrol function and applied to the inverter is configured so that
between 0.98 and 1.02 p.u. of voltage, the curve presents a dead band, not
generating or absorbing reactive power. The control tested in this section is
for the condition of maximum penetration of PVs. In the first case the
inverter power is set at 432 kVA, 120% of the expected value for the maxi-
mum power generated (VV), and in the second case the inverter power is