ABSTRACT:
A distribution static compensator
(DSTATCOM) is used for load voltage regulation and its performance mainly depends
upon the feeder impedance and its nature (resistive, inductive, stiff, non-stiff).
However, a study for analyzing voltage regulation performance of DSTATCOM
depending upon network parameters is not well defined. This paper aims to
provide a comprehensive study of design, operation, and flexible control of a
DSTATCOM operating in voltage control mode. A detailed analysis of the voltage
regulation capability of DSTATCOM under various feeder impedances is presented.
Then, a benchmark design procedure to compute the value of external inductor is
presented. A dynamic reference load voltage generation scheme is also developed
which allows DSTATCOM to compensate load reactive power during normal
operation, in addition to providing voltage support during disturbances.
Simulation and experimental results validate the effectiveness of the proposed scheme.
KEYWORDS :
1. Distribution
static compensator (DSTATCOM)
2. Current
control
3. Voltage
control
4. Power
factor
5. Power
quality
SOFTWARE:
MATLAB/SIMULINK
EQUIVALENT CIRCUIT DIAGRAM:
Fig.
1. Three phase equivalent circuit of DSTATCOM topology in distribution system.
EXPECTED SIMULATION RESULTS:
Fig.
2. Voltage regulation performance of conventional DSTATCOM with resistive
feeder. (a) PCC voltages. (b) Load Voltages. (c) Source currents. (d) Filter
currents. (e) Load currents.
Fig.
3. Simulation results. (a) During normal operation (i)-(v). (b) During voltage
sag (vi)-(x). (c) During voltage swell (xi)-(xv).
CONCLUSION:
This paper has presented design,
operation, and control of a DSTATCOM operating in voltage control mode (VCM). After
providing a detailed exploration of voltage regulation capability of DSTATCOM
under various feeder scenarios, a benchmark design procedure for selecting
suitable value of external inductor is proposed. An algorithm is formulated for
dynamic reference load voltage magnitude generation. The DSTATCOM has improved
voltage regulation capability with a reduced current rating VSI, reduced losses
in the VSI and feeder. Also, dynamic reference load voltage generation scheme
allows DSTATCOM to set different constant reference voltage during voltage
disturbances. Simulation and experimental results validate the effectiveness of
the proposed solution. The external inductor is a very simple and cheap
solution for improving the voltage regulation, however it remains connected
throughout the operation and continuous voltage drop across it occurs. The future
work includes operation of this fixed inductor as a controlled reactor so that
its effect can be minimized by varying its inductance.
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