Title: Design and Construction of Variable Power Output for Hydrogenerator
II.INTRODUCTION:
Hydrogerator is designed to capture electricity through water flow. It consists of three
main parts which are the 1)turbine 2)generator 3) shaft. Hydrogenerator is low in rpm but the
torque to turn the generator is high, which produces more current, there are 2 places the
hydrogenerator is placed 1)dams 2)rivers . For dam, big hydrogenerator is used and also higher
turbine torque to maximize the current the dam generates. In river, the turbine torque is low and
also low rpm, depending on the river current the rpm can be more fast but the turbine torque is
fixed, if the water current is fast the rpm of the generator will increase which produces more
voltage. Depending on the application of hydrogenerator, it is a efficient way to harness energy
with water current. Hydrogenerators have 50% to 80% efficiency depending where the turbine is
placed. There are many different turbines use for hydrogenerator. For dam, the commonly used
turbine is Pelton turbine, it is used because it design like a cup, the purpose of it is to capture
more weight of the water which is very ideal for high torque generator but it is known for its low
rpm due to weight of the turbine. In river, the most common turbine used is Francis turbine, it
design for high rpm and but the torque is not the same Pelton turbine. Hydrogenerator output
can produce 2kW to 100mW of power depending of its size and application.
Ac generator is used for hydrogenerator because of its efficiency and balanced
sinusoidal waveform. Using Ac voltage as an energy will make it more cheaper and reliable,
because of the less use of converters to make it work, also, the energy in the power grid run on
Ac voltage. Many houses and industries rely on Ac voltage because of its efficiency and low
power loss.
Variable output power generators use gear ratio to adapt with the water current, it uses
its gear ratio to adjust turbine torque and the rpm of the generator. By using its gear ratio it can
spin continuously depending on the water current.
This research focuses on the design of a hydrogenerator which uses gear ratio to adapt
to water current. The continuous spin of the turbine will produce clean and efficient energy.
III.STATEMENT OF THE PROBLEM
Some places near dams or river rely on hydrogenerator as source of energy. The
common issue of a hydrogenerator is that it is stop spinning if the water current decreases
because it is design for a certain water current flow. Overtime, the demand of electricity in
philippines is getting higher because of the newer technologies that eat a lot of power. Many
barangay have rivers that don’t have renewable energy and still rely on a power grid which is
costing the people more money to pay for electricity. Having these demands for electricity will
cost a lot of money to operate and implement. Also, hydrogenerator especially on dams only run
on specific time, it relies on the time whenever the dam is overflow or the time the water valve is
open, if the dam reaches to a certain water level the water supply or switch is cut off which
causes the hydrogenerator to stop spinning.
The demand for hydrogenerator is getting higher because of the advancement and new
technologies. Hydrogenerator in dams have 80% to 90% percent efficiency according to
ScienceDirect. In river, like pico-hydrogenerator have 50% to 80% efficiency, it also depends on
the current flow and the energy demand for it. 4.6% percent on philippine electricity come from
hydro, from solar 0.7%, and from wind is 0.6% according to Energy Tracker Asia, the rest of it
rely on gas or diesel electricity produce from power plants. Over 27% percent of philippines is
river according to the Senate of the Philippines. Also,
15 operational dams according to
Hydropower and Dams International.
Due to increasing demands of electricity, the following problems that the study wants to resolve:
1.​ Determine the maximum operation of a variable power output hydrogenerator.
2.​ Determine the adaptability of variable power output hydrogenerator in rural areas.
3.​ Determine maximum efficiency of using variable gears to increase the voltage and
current.
4.​ Determine the issue of the traditional hydrogenerators.
5.​ Determine the pressure head of the waterflow where the hydrogenerator is installed.