ABSTRACT:
As a renewable resource, small hydro is gaining more
and more attention due to its variable advantages. The paper focuses on the
operation of the micro-grid based on small-hydro. A simulation model of the
micro-grid is established by Simulink, which takes the following two cases into
account, the grid-connected operation and isolated operation. Under these two cases,
the differences of the excitation voltage and rotator speed are analyzed
respectively. Power quality of the voltage is also analyzed. Faults are pre-set
in the grid and micro-grid. Then the operations of the micro-grid when faults
happen are simulated. By comparison of the results, the effects of the
fault-cutting-off time are discussed.
KEYWORDS:
1.
Small-hydro
2.
Micro-grid
3.
Model
4.
Simulation
5.
Faults
SOFTWARE: MATLAB/SIMULINK
SIMULING BLOCK DIAGRAM:
EXPECTED SIMULATION RESULTS:
Fig. 2. Field voltage of generator
Fig. 3. Rotator speed of generator
Fig. 4. Output voltage (RMS) of
generator 1(THD=0.80%)
Fig. 5. Active power assumption of load 1
Fig. 6. Field voltage of
generator
Fig. 7. Rotator speed of generator
Fig. 8. Output voltage (RMS) of generator 1(THD=1.91%)
Fig. 9. Active power assumption of load 1
Fig.
10. Field voltage of generator
Fig. 11. Rotator speed of generator
Fig. 12. Output voltage (RMS) of
generator 1
Fig. 13. Active power assumption
of load 1
Fig. 14. Field voltage of generator
Fig.
15. Rotator speed of generator
Fig. 16. Output voltage (RMS) of
generator 1
Fig. 17. Active power assumption
of load 1
Fig. 18. Field voltage of generator
Fig. 19. Rotator speed of
generator
Fig. 20.
Output voltage (RMS) of generator 1
Fig. 21. Active power assumption
of load 1
CONCLUSION:
The
micro-grid based on small-hydro can work normally without disturbance by
simulating the grid-connected operation and islanded operation. The power
quality would have been improved when the micro-grid connected to the grid by comparing
the waveforms of output voltage and active power assumption. And the THD would
have decreased when the micro grid is in grid-connected operation. Analyze the recovering
time and influence of fault-cutting time by setting fault to the micro-grid and
grid. The simulation results stress the importance of fault-cutting time.
Cutting off the fault in time would suppress the system oscillation, and the
generators are easier to get synchronous again. The system would oscillate fiercely
with high frequency if the fault could not be cut off in time. However, the
actual situation is more complex. Considering the change of load, actual
situation of small-hydro power plants (changes of water level and so on),
development of different distributing power and so on, the structure of the conventional
micro-grid will become more complex, so the model in the paper needs some
improvement.
REFERENCES:
[1]
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[2]
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[3]
ZHANG YuanSheng, et al. “The effects on the load model of the distributed
network with small hydro power.” 2011 The International Conference on
Advanced Power System Automation and Protection, China, 2011,
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[4]
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[5]
Guillermo C. Zu˜niga-Neria, Fernando Ornelas-Tellez,J. Jesus Rico. “Optimal
Operation of Energy Resources in a Micro-grid.” Power Systems Conference,
USA, 2014, pp. 1-6.
