2011 International Conference on Alternative Energy in Developing Countries and Emerging Economies
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Fig. 7 The IGC system response.
The system response with PID parameters:
p
K
=-
50,
i
T
=5 and
d
T
=1 is most efficient. The maximum
percentage overshoot is a very small value if compared
with the other parameters. Accordingly, the rise time is
slightly smaller than the other parameters. As can be
seen, a fairly good voltage regulation is achieved when
the load is changed at 2 milliseconds.
Fig. 8 shows the experimental values of the load
voltage, and the current of the transient waveforms of the
SEIG-IGC at the selected operating point of 100 W. Fig.
9 shows the experimental waveforms of voltage and
current when the main load is reduced by 50% of the full
load, while Fig. 10 shows the experimental waveforms of
voltage and current when no main load is connected in
the SEIG terminal.
At the application of the consumer load, an IGC
current decrease shows the transfer of energy from the
IGC to the consumer loads and maintains the load
constant on the SEIG. From these waveforms under
consumer load, the SEIG voltage and current are
observed to be close to sinusoidal.
(a)
(b)
Fig. 8 Experimental waveforms of (a) voltage and (b) PWM when the
main load is full-load value.
(a)
(b)
Fig. 9 Experimental waveforms of (a) voltage and (b) PWM when the
main load is reduced by 50% of the full load value.
(a)
(b)
Fig. 10 Experimental waveforms of (a) voltage and (b) PWM without
main load.
Steady-state responses of dump load power, SEIG
voltage, and frequency with variation in the consumer
load for IGC. It is found that dump load power decreases
with an increase in the consumer load. The SEIG
voltages and frequency both remain approximately the
same under both full consumer load and dump load as
shown in Fig. 11.
The performance of the IGC under various operating
conditions is able to give a voltage regulation of +/-5%,
which is good enough for stand-alone pico-hydro
generation system. It can be seen that the proposed
microcontroller-based SEIG-IGC is effective in terms of
sharing a constant generated power of 100 W between
the main load and the dump load, when the main or
consumer load is changed.
0
20
40
60
80
100
120
140
160
1 3 5 7 9 11 13 15 17 19 21
time (10xmillisencond)
ADC
input
set point
