Multi converter Unified
Power-Quality Conditioning System: MC-UPQC
ABSTRACT:
This paper presents a new unified power-quality
conditioning system (MC-UPQC), capable of simultaneous compensation for voltage
and current in multi bus/multi feeder systems. In this configuration, one shunt
voltage-source converter (shunt VSC) and two or more series VSCs exist. The
system can be applied to adjacent feeders to compensate for supply-voltage and
load current imperfections on the main feeder and full compensation of supply voltage
imperfections on the other feeders. In the proposed configuration, all
converters are connected back to back on the dc side and share a common dc-link
capacitor. Therefore, power can be transferred from one feeder to adjacent
feeders to compensate for sag/swell and interruption. The performance of the
MC-UPQC as well as the adopted control algorithm is illustrated by simulation. The
results obtained in PSCAD/EMTDC on a two-bus/two-feeder system show the
effectiveness of the proposed configuration.
KEYWORDS:
1.
Power quality
(PQ)
2.
PSCAD/EMTDC
3.
Unified power-quality conditioner (UPQC)
4.
voltage-source converter (VSC)
SOFTWARE: MATLAB/SIMULINK
BLOCK DIAGRAM:
Fig.1.
Typical MC-UPQC used in a distribution system.
Fig.2.
Control block diagram of the shunt VSC.
Fig.3.
Control block diagram of the series VSC.
CONCLUSION:
In
this paper, a new configuration for simultaneous compensation of voltage and
current in adjacent feeders has been proposed. The new configuration is named
multi converter unified power-quality conditioner (MC-UPQC). Compared to a
conventional UPQC, the proposed topology is capable of fully protecting
critical and sensitive loads against distortions, sags/swell, and interruption
in two-feeder systems. The idea can be theoretically extended to multi bus/multi
feeder systems by adding more series VSCs. The performance of the MC-UPQC is evaluated
under various disturbance conditions and it is shown that the proposed MC-UPQC
offers the following advantages:
1)
power transfer between two adjacent feeders for sag/swell and interruption
compensation;
2)
compensation for interruptions without the need for a battery storage system
and, consequently, without storage capacity limitation;
3)
sharing power compensation capabilities between two adjacent feeders which are
not connected.
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