Difference between revisions of "Electrical-Mechanical Equipment"

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== Introduction  ==
+
== [[Category:Hydro]]Introduction  ==
  
<u>disambiguation</u>:<br>  
+
<u>disambiguation</u>:<br>
  
grid connection<br>  
+
grid connection<br>
  
island / isolated grids<br>  
+
island / isolated grids<br>
  
 
battery storage / charging stations  
 
battery storage / charging stations  
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== '''Off-Grid Battery-Based Microhydro-Electric Systems'''  ==
 
== '''Off-Grid Battery-Based Microhydro-Electric Systems'''  ==
  
<span>Most small off-grid hydro systems are battery-based. Battery  
+
<span>Most small off-grid hydro systems are battery-based. Battery systems have great flexibility and can be combined with other energy sources, such as wind generators and solar-electric arrays, if the stream is seasonal. Because stream flow is usually consistent, battery charging is as well, and it´s often possible to use a relatively </span>
systems have great flexibility and can be
 
combined with other energy sources, such as wind generators and  
 
solar-electric
 
arrays, if the stream is seasonal. Because stream flow is usually  
 
consistent,
 
battery charging is as well, and it´s often possible to use a relatively
 
</span>
 
  
 
  small
 
  small
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battery bank. Instantaneous demand (watts) will be limited not by the water potential or turbine, but by the size of the inverter.  
 
battery bank. Instantaneous demand (watts) will be limited not by the water potential or turbine, but by the size of the inverter.  
  
<span>The following illustration includes the primary
+
<span>The following illustration includes the primary components of any off-grid battery-based microhydro-electric system..</span>  
components of any off-grid battery-based microhydro-electric system..</span>  
 
  
picture... <br> &nbsp;  
+
picture... <br>&nbsp;  
  
 
== '''Off-Grid Batteryless Microhydro-Electric Systems'''  ==
 
== '''Off-Grid Batteryless Microhydro-Electric Systems'''  ==
  
<span>If the stream has enough potential, one may decide to
+
<span>If the stream has enough potential, one may decide to go with an AC-direct system. This consists of a turbine generator that produces AC output at 120 or 240 volts, which can be sent directly to standard household loads. The system is controlled by diverting energy in excess of load requirements to dump loads, such as water- or air-heating elements. This technique keeps the total load on the generator constant. A limitation of these systems is that the peak or surge loads cannot exceed the output of the generator, which is determined by the stream´s available head and flow. This type of system needs to be large to meet peak electrical loads, so it can often generate enough energy for all household needs, including water and space heating.</span>  
go with an AC-direct system. This consists of a turbine generator that  
 
produces
 
AC output at 120 or 240 volts, which can be sent directly to standard  
 
household
 
loads. The system is controlled by diverting energy in excess of load  
 
requirements
 
to dump loads, such as water- or air-heating elements. This technique  
 
keeps the
 
total load on the generator constant. A limitation of these systems is  
 
that the
 
peak or surge loads cannot exceed the output of the generator, which is
 
determined by the stream´s available head and flow. This type of system  
 
needs
 
to be large to meet peak electrical loads, so it can often generate  
 
enough
 
energy for all household needs, including water and space heating.</span>  
 
  
<span>The following illustration includes the primary components
+
<span>The following illustration includes the primary components of any off-grid batteryless microhydro-electric system. </span>
of any off-grid batteryless microhydro-electric system. </span>  
 
  
 
<!--{12766841534923}-->picture ....  
 
<!--{12766841534923}-->picture ....  
  
<br>  
+
<br>
  
 
&nbsp;  
 
&nbsp;  
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== '''Grid-Tied Batteryless Microhydro-Electric Systems'''  ==
 
== '''Grid-Tied Batteryless Microhydro-Electric Systems'''  ==
  
<span>Systems of this type use a turbine and controls to
+
<span>Systems of this type use a turbine and controls to produce electricity that can be fed directly into utility lines. These can use either AC or DC generators. AC systems will use AC generators to sync directly with the grid. An approved interface device is needed to prevent the system from energizing the grid when the grid is out of action and under repair. DC systems will use a specific inverter to convert the output of a DC hydro turbine to grid-synchronous AC. The biggest drawback of batteryless systems is that when the utility is down, your electricity will be out too. When the grid fails, these systems are designed to automatically shut down.</span>  
produce electricity that can be fed directly into utility lines. These  
 
can use
 
either AC or DC generators. AC systems will use AC generators to sync  
 
directly
 
with the grid. An approved interface device is needed to prevent the  
 
system
 
from energizing the grid when the grid is out of action and under  
 
repair. DC
 
systems will use a specific inverter to convert the output of a DC hydro
 
turbine to grid-synchronous AC. The biggest drawback of batteryless  
 
systems is
 
that when the utility is down, your electricity will be out too. When  
 
the grid
 
fails, these systems are designed to automatically shut down.</span>  
 
  
<span>The following illustration includes the primary
+
<span>The following illustration includes the primary components of any grid-tied batteryless microhydro-electric system. </span>
components of any grid-tied batteryless microhydro-electric system. </span>  
 
  
 
<!--{12766841534924}-->&nbsp;  
 
<!--{12766841534924}-->&nbsp;  
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[[|]]'''<span>Microhydro-Electric</span>''' System Components  
 
[[|]]'''<span>Microhydro-Electric</span>''' System Components  
  
'''Controls'''<span>
+
'''Controls'''<span> </span>
</span>  
 
  
 
AKA: Charge controller, controller, regulator  
 
AKA: Charge controller, controller, regulator  
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&nbsp;  
 
&nbsp;  
  
<span>The function of a
+
<span>The function of a charge controller in a hydro system is equivalent to turning on a load to absorb excess energy. Battery-based microhydro systems require charge controllers to prevent overcharging the batteries. Controllers generally </span>
charge controller in a hydro system is equivalent to turning on a load  
 
to
 
absorb excess energy. Battery-based microhydro systems require charge
 
controllers to prevent overcharging the batteries. Controllers generally
 
</span>
 
  
 
  send
 
  send
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excess energy to a secondary (dump) load, such as an air or water heater. Unlike a solar-electric controller, a microhydro system controller does not disconnect the turbine from the batteries. This could create voltages that are higher than some components can withstand, or cause the turbine to&nbsp;overspeed, which could result in dangerous and damaging overvoltages.  
 
excess energy to a secondary (dump) load, such as an air or water heater. Unlike a solar-electric controller, a microhydro system controller does not disconnect the turbine from the batteries. This could create voltages that are higher than some components can withstand, or cause the turbine to&nbsp;overspeed, which could result in dangerous and damaging overvoltages.  
  
<span>Off-grid, batteryless
+
<span>Off-grid, batteryless AC-direct microhydro systems need controls too. A load-control governor monitors the voltage or frequency of the system, and keeps the generator correctly loaded, turning dump-load capacity on and off as the load pattern changes, or mechanically deflects water away from the runner. Grid-tied batteryless AC and DC systems also need controls to protect the system if the utility grid fails.</span>  
AC-direct microhydro systems need controls too. A load-control governor
 
monitors the voltage or frequency of the system, and keeps the generator
 
correctly loaded, turning dump-load capacity on and off as the load  
 
pattern
 
changes, or mechanically deflects water away from the runner. Grid-tied
 
batteryless AC and DC systems also need controls to protect the system  
 
if the
 
utility grid fails.</span>  
 
  
 
== '''Dump Load'''  ==
 
== '''Dump Load'''  ==
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<!--{12766841534926}-->[[Image:|Dump Load 1]]<!--{12766841534927}-->[[Image:|Dump Load 2]]  
 
<!--{12766841534926}-->[[Image:|Dump Load 1]]<!--{12766841534927}-->[[Image:|Dump Load 2]]  
  
<span>A dump
+
<span>A dump load is an electrical resistance heater that must be sized to handle the </span>
load is an electrical resistance heater that must be sized to handle the
 
</span>
 
  
 
  full
 
  full
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<!--{12766841534928}-->[[Image:|Battery Bank]]  
 
<!--{12766841534928}-->[[Image:|Battery Bank]]  
  
<span>By using
+
<span>By using reversible chemical reactions, a battery bank provides a way to store surplus energy when more is being produced than consumed. When demand increases beyond what is generated, the batteries can be called on to release energy to keep your household loads operating.</span>  
reversible chemical reactions, a battery bank provides a way to store  
 
surplus
 
energy when more is being produced than consumed. When demand increases  
 
beyond
 
what is generated, the batteries can be called on to release energy to  
 
keep
 
your household loads operating.</span>  
 
  
<span>A
+
<span>A microhydro system is typically the most gentle of the RE systems on the batteries, since they do not often remain in a discharged state. The bank can also be smaller than for a wind or PV system. One or two days of storage </span>
microhydro system is typically the most gentle of the RE systems on the
 
batteries, since they do not often remain in a discharged state. The  
 
bank can
 
also be smaller than for a wind or PV system. One or two days of storage
 
</span>
 
  
 
  is
 
  is
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== '''Metering'''  ==
 
== '''Metering'''  ==
  
<span>AKA:
+
<span>AKA: battery monitor, amp-hour meter, watt-hour meter</span>  
battery monitor, amp-hour meter, watt-hour meter</span>  
 
  
 
<!--{12766841534929}-->[[Image:|Metering]]  
 
<!--{12766841534929}-->[[Image:|Metering]]  
  
<span>System
+
<span>System meters measure and display several different aspects of your microhydro-electric system´s performance and status—tracking how full your battery bank is, how much electricity your turbine is producing or has produced, and how much electricity is being used. Operating your system without metering is like running your car without any gauges—although possible to do, it´s always better to know how well the car is operating and how much fuel is in the tank.</span>  
meters measure and display several different aspects of your
 
microhydro-electric system´s performance and status—tracking how full  
 
your
 
battery bank is, how much electricity your turbine is producing or has
 
produced, and how much electricity is being used. Operating your system  
 
without
 
metering is like running your car without any gauges—although possible  
 
to do,
 
it´s always better to know how well the car is operating and how much  
 
fuel is
 
in the tank.</span>  
 
  
 
&nbsp;  
 
&nbsp;  
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<!--{127668415349210}-->[[Image:|Main DC Disconnect]]  
 
<!--{127668415349210}-->[[Image:|Main DC Disconnect]]  
  
<span>In
+
<span>In battery-based systems, a disconnect between the batteries and inverter is required. This disconnect is typically a large, DC-rated breaker mounted </span>
battery-based systems, a disconnect between the batteries and inverter  
 
is
 
required. This disconnect is typically a large, DC-rated breaker mounted
 
</span>
 
  
 
  in a
 
  in a
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== '''Inverter'''  ==
 
== '''Inverter'''  ==
  
<span>AKA: DC-to-AC
+
<span>AKA: DC-to-AC converter </span>
converter </span>  
 
  
<!--{127668415349211}-->[[Image:|Battery-Based Inverter]]<span>Inverters
+
<!--{127668415349211}-->[[Image:|Battery-Based Inverter]]<span>Inverters transform </span>
transform
 
</span>
 
  
 
  the DC electricity stored in your battery bank into AC electricity
 
  the DC electricity stored in your battery bank into AC electricity
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for powering household appliances. Grid-tied inverters synchronize the system´s output with the utility´s AC electricity, allowing the system to feed hydro-electricity to the utility grid. Battery-based inverters for off-grid or grid-tied systems often include a battery charger, which is capable of charging a battery bank from either the grid or a backup generator if your creek isn´t flowing or your system is down for maintenance.  
 
for powering household appliances. Grid-tied inverters synchronize the system´s output with the utility´s AC electricity, allowing the system to feed hydro-electricity to the utility grid. Battery-based inverters for off-grid or grid-tied systems often include a battery charger, which is capable of charging a battery bank from either the grid or a backup generator if your creek isn´t flowing or your system is down for maintenance.  
  
<span>In rare
+
<span>In rare cases, an inverter and battery bank are used with larger, off-grid AC-direct systems to increase power availability. The inverter uses the AC to charge the batteries, and synchronizes with the hydro-electric AC supply to supplement it when demand is greater than the output of the hydro generator.</span>  
cases, an inverter and battery bank are used with larger, off-grid  
 
AC-direct
 
systems to increase power availability. The inverter uses the AC to  
 
charge the
 
batteries, and synchronizes with the hydro-electric AC supply to  
 
supplement it
 
when demand is greater than the output of the hydro generator.</span>  
 
  
 
[[|]]'''<span>AC</span>''' Breaker Panel  
 
[[|]]'''<span>AC</span>''' Breaker Panel  
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<!--{127668415349212}-->[[Image:|AC Breaker Panel]]  
 
<!--{127668415349212}-->[[Image:|AC Breaker Panel]]  
  
<span>The AC
+
<span>The AC breaker panel, or mains panel, is the point at which all of a home´s electrical wiring meets with the provider of the electricity, whether that´s the grid or a microhydro-electric system. This wall-mounted panel or box is usually installed in a utility room, basement, garage, or on the exterior of a building. It contains a number of labeled circuit breakers that route electricity to the various rooms throughout a house. These breakers allow electricity to be disconnected for servicing, and also protect the building´s wiring against electrical </span>
breaker panel, or mains panel, is the point at which all of a home´s  
 
electrical
 
wiring meets with the provider of the electricity, whether that´s the  
 
grid or a
 
microhydro-electric system. This wall-mounted panel or box is usually  
 
installed
 
in a utility room, basement, garage, or on the exterior of a building.  
 
It
 
contains a number of labeled circuit breakers that route electricity to  
 
the various
 
rooms throughout a house. These breakers allow electricity to be  
 
disconnected
 
for servicing, and also protect the building´s wiring against electrical
 
</span>
 
  
 
  fires.  
 
  fires.  
  
<span>Just like
+
<span>Just like the electrical circuits in your home or office, a grid-tied inverter´s electrical output needs to be routed through an AC circuit breaker. This breaker is usually mounted inside the building´s mains panel. It enables </span>
the electrical circuits in your home or office, a grid-tied inverter´s
 
electrical output needs to be routed through an AC circuit breaker. This
 
breaker is usually mounted inside the building´s mains panel. It enables
 
</span>
 
  
 
  the
 
  the
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[[|]]'''Kilowatt-Hour Meter'''  
 
[[|]]'''Kilowatt-Hour Meter'''  
  
<span>AKA: KWH
+
<span>AKA: KWH meter, utility meter</span>  
meter, utility meter</span>  
 
  
 
<!--{127668415349213}-->[[Image:|Kilowatt-Hour Meter]]  
 
<!--{127668415349213}-->[[Image:|Kilowatt-Hour Meter]]  
  
<span>Most
+
<span>Most homes with grid-tied microhydro-electric systems will have AC electricity both coming from and going to the utility grid. A multichannel KWH meter keeps track of how much grid electricity you´re using and how much your RE system is producing. The utility company often provides intertie-capable meters at </span>
homes with grid-tied microhydro-electric systems will have AC  
 
electricity both
 
coming from and going to the utility grid. A multichannel KWH meter  
 
keeps track
 
of how much grid electricity you´re using and how much your RE system is
 
producing. The utility company often provides intertie-capable meters at
 
</span>
 
  
 
  no
 
  no
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<span><!--{127668415349214}-->[[Image:]]</span>  
 
<span><!--{127668415349214}-->[[Image:]]</span>  
  
<span>A turbine converts the energy in
+
<span>A turbine converts the energy in falling water into shaft power. There are various types of turbine which </span>
falling water into shaft power. There are various types of turbine which
 
</span>
 
  
 
  can be
 
  can be
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{| cellpadding="0" border="1"
 
{| cellpadding="0" border="1"
 
|-
 
|-
| valign="top" rowspan="2" | <br>  
+
| valign="top" rowspan="2" | <br>
'''<span>Turbine</span> '''  
+
'''<span>Turbine</span>'''
  
'''Runner'''  
+
'''Runner'''
  
 
| valign="top" align="center" colspan="3" |  
 
| valign="top" align="center" colspan="3" |  
'''<span>Head</span> '''  
+
'''<span>Head</span>'''
  
'''pressure'''  
+
'''pressure'''
  
 
|-
 
|-
 
| valign="top" align="center" |  
 
| valign="top" align="center" |  
'''High'''  
+
'''High'''
  
 
| valign="top" align="center" |  
 
| valign="top" align="center" |  
'''Medium'''  
+
'''Medium'''
  
 
| valign="top" align="center" |  
 
| valign="top" align="center" |  
'''Low'''<br>  
+
'''Low'''<br>
  
 
|-
 
|-
 
| valign="top" |  
 
| valign="top" |  
Impulse  
+
Impulse
  
 
| valign="top" |  
 
| valign="top" |  
<span>Pelton
+
<span>Pelton </span>
</span>  
 
  
 
Turgo  
 
Turgo  
  
Multi-jet Pelton <br>  
+
Multi-jet Pelton <br>
  
 
| valign="top" |  
 
| valign="top" |  
<span>Crossflow
+
<span>Crossflow </span>
</span>  
 
  
 
Turgo  
 
Turgo  
  
Multi-jet Pelton <br>  
+
Multi-jet Pelton <br>
  
 
| valign="top" |  
 
| valign="top" |  
Crossflow  
+
Crossflow
  
 
|-
 
|-
 
| valign="top" |  
 
| valign="top" |  
Reaction  
+
Reaction
  
 
| valign="top" |  
 
| valign="top" |  
<span>Francis
+
<span>Francis </span>
</span>  
 
  
Pump-as-turbine (PAT) <br>  
+
Pump-as-turbine (PAT) <br>
  
 
| valign="top" |  
 
| valign="top" |  
<span>Propeller
+
<span>Propeller </span>
</span>  
 
  
Kaplan <br>  
+
Kaplan <br>
  
 
| valign="top" |  
 
| valign="top" |  
&nbsp;  
+
&nbsp;
  
 
|}
 
|}
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'''&nbsp;'''  
 
'''&nbsp;'''  
  
<span>The difference between impulse and
+
<span>The difference between impulse and reaction can be explained simply by stating that the ''impulse'' turbines convert the kinetic energy of a jet of water in air into movement by striking turbine buckets or blades - there is no pressure reduction as the water pressure is atmospheric on both sides of the impeller. The blades of a ''reaction'' turbine, on the other hand, are totally immersed in the flow of water, and the angular as well as linear momentum of the water is converted into shaft power - the pressure of water leaving the runner is reduced to atmospheric or lower. </span>
reaction can be explained simply by stating that the ''impulse''  
 
turbines
 
convert the kinetic energy of a jet of water in air into movement by  
 
striking
 
turbine buckets or blades - there is no pressure reduction as the water
 
pressure is atmospheric on both sides of the impeller. The blades of a ''reaction''
 
turbine, on the other hand, are totally immersed in the flow of water,  
 
and the
 
angular as well as linear momentum of the water is converted into shaft  
 
power -
 
the pressure of water leaving the runner is reduced to atmospheric or  
 
lower. </span>  
 
  
 
== '''Load factor'''  ==
 
== '''Load factor'''  ==
  
<span>The load factor is the amount of
+
<span>The load factor is the amount of power used divided by the amount of power that is available if the turbine were to be used continuously. Unlike technologies relying on costly fuel sources, the 'fuel' for hydropower generation is free and therefore the plant becomes more cost effective if run for a high percentage of the time. If the turbine is only used for domestic lighting in the evenings then the plant factor will be very low. If the turbine provides power for rural industry during the day, meets domestic demand during the evening, and maybe pumps water for irrigation in the evening, then the plant factor will be high. </span>
power used divided by the amount of power that is available if the  
 
turbine were
 
to be used continuously. Unlike technologies relying on costly fuel  
 
sources,
 
the 'fuel' for hydropower generation is free and therefore the plant  
 
becomes
 
more cost effective if run for a high percentage of the time. If the  
 
turbine is
 
only used for domestic lighting in the evenings then the plant factor  
 
will be
 
very low. If the turbine provides power for rural industry during the  
 
day,
 
meets domestic demand during the evening, and maybe pumps water for  
 
irrigation
 
in the evening, then the plant factor will be high. </span>  
 
  
<span>It is very important to ensure a
+
<span>It is very important to ensure a high plant factor if the scheme is to be cost effective and this should be taken into account during the planning stage. Many schemes use a 'dump' load (in conjunction with an electronic load controller - see below), which is effectively a low priority energy demand that can accept surplus energy when an excess is produced e.g. water heating, storage heaters or storage cookers. </span>
high plant factor if the scheme is to be cost effective and this should  
 
be
 
taken into account during the planning stage. Many schemes use a 'dump'  
 
load
 
(in conjunction with an electronic load controller - see below), which  
 
is
 
effectively a low priority energy demand that can accept surplus energy  
 
when an
 
excess is produced e.g. water heating, storage heaters or storage  
 
cookers. </span>  
 
  
 
== '''Load control governors'''  ==
 
== '''Load control governors'''  ==
  
<span>Water turbines, like petrol or
+
<span>Water turbines, like petrol or diesel engines, will vary in speed as load is applied or relieved. Although not such a great problem with machinery which uses direct shaft power, this speed variation will seriously affect both frequency and voltage output from a generator. Traditionally, complex hydraulic or mechanical speed governors altered flow as the load varied, but more recently an electronic load controller (ELC) has been developed which has increased the simplicity and reliability of modern micro-hydro sets. The ELC prevents speed variations by continuously adding or subtracting an artificial load, so that in effect, the turbine is working permanently under full load. A further benefit is that the ELC has no moving parts, is very reliable and virtually maintenance free. The advent of electronic load control has allowed the introduction of simple </span>
diesel engines, will vary in speed as load is applied or relieved.  
 
Although not
 
such a great problem with machinery which uses direct shaft power, this  
 
speed
 
variation will seriously affect both frequency and voltage output from a
 
generator. Traditionally, complex hydraulic or mechanical speed  
 
governors
 
altered flow as the load varied, but more recently an electronic load
 
controller (ELC) has been developed which has increased the simplicity  
 
and
 
reliability of modern micro-hydro sets. The ELC prevents speed  
 
variations by
 
continuously adding or subtracting an artificial load, so that in  
 
effect, the
 
turbine is working permanently under full load. A further benefit is  
 
that the
 
ELC has no moving parts, is very reliable and virtually maintenance  
 
free. The
 
advent of electronic load control has allowed the introduction of simple
 
</span>
 
  
 
  and
 
  and
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efficient, multi-jet turbines, no longer burdened by expensive hydraulic governors.&nbsp;  
 
efficient, multi-jet turbines, no longer burdened by expensive hydraulic governors.&nbsp;  
  
<br>  
+
<br>
  
== Controller: <br> ==
+
== Controller: <br> ==
  
<!--{12766848790530}--><!--{12766848790531}--> <!--{12766848790532}-->  
+
<!--{12766848790530}--><!--{12766848790531}--><!--{12766848790532}-->
  
<span id="1274973221030S" style="display: none;">&nbsp;</span>  
+
<span id="1274973221030S" style="display: none">&nbsp;</span>  
  
<!--{12766848790533}--><!--{12766848790534}--><!--{12766848790535}--><span lang="DE" style="font-size: 11pt; font-family: Tahoma; color: black;">Function </span><span lang="DE" style="font-size: 11pt; font-family: Tahoma; color: black;">[[Image:Mhp-scheme.jpg|right|560x386px|Elements of a Micro Hydro  Power Scheme]]principles</span><br>  
+
<!--{12766848790533}--><!--{12766848790534}--><!--{12766848790535}--><span lang="DE" style="font-size: 11pt; color: black; font-family: tahoma">Function </span><span lang="DE" style="font-size: 11pt; color: black; font-family: tahoma">[[Image:Mhp-scheme.jpg|right|558x386px|Elements of a Micro Hydro  Power Scheme]]principles</span><br>
  
Load- or Flow- controller ensure that the power output does not exceed the power demand (e.g. 230V, 50 Hz). <br> If flow of water in a MHP-station is constant the energy output of a turbine/generator is constant as well. Power demand is usually fluctuating over the time (e.g. day/night). If supply is higher than demand, excess energy must be diverted, dumped. alternatively the water flow can be reduced which results in less power output. <br> In case of more power demand than supply the controller cuts of the of demand line. <br> Load controller are placed between generator output and the consumer line.<!--{12766848790536}--> <span lang="DE" style="font-size: 11pt; font-family: Tahoma; color: black;">
+
Load- or Flow- controller ensure that the power output does not exceed the power demand (e.g. 230V, 50 Hz). <br>If flow of water in a MHP-station is constant the energy output of a turbine/generator is constant as well. Power demand is usually fluctuating over the time (e.g. day/night). If supply is higher than demand, excess energy must be diverted, dumped. alternatively the water flow can be reduced which results in less power output. <br>In case of more power demand than supply the controller cuts of the of demand line. <br>Load controller are placed between generator output and the consumer line.<!--{12766848790536}--> <span lang="DE" style="font-size: 11pt; color: black; font-family: tahoma" />
</span>  
 
  
<br>  
+
<br>
  
<br>  
+
<br>
  
<br>  
+
<br>
  
<br>  
+
<br>
  
<!--{12766848790537}--><!--{12766848790538}--> <!--{12766848790539}-->  
+
<!--{12766848790537}--><!--{12766848790538}--><!--{12766848790539}-->
  
=== <span lang="DE" style="font-size: 11pt; font-family: Tahoma; color: black;">Controller Types</span>  ===
+
=== <span lang="DE" style="font-size: 11pt; color: black; font-family: tahoma">Controller Types</span>  ===
  
 
==== Load controller:  ====
 
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Electronic circuit, which keeps output power constant in Frequency- and Voltage- parameters.  
 
Electronic circuit, which keeps output power constant in Frequency- and Voltage- parameters.  

Revision as of 11:03, 16 June 2010

Introduction

disambiguation:

grid connection

island / isolated grids

battery storage / charging stations

Off-Grid Battery-Based Microhydro-Electric Systems

Most small off-grid hydro systems are battery-based. Battery systems have great flexibility and can be combined with other energy sources, such as wind generators and solar-electric arrays, if the stream is seasonal. Because stream flow is usually consistent, battery charging is as well, and it´s often possible to use a relatively

small

battery bank. Instantaneous demand (watts) will be limited not by the water potential or turbine, but by the size of the inverter.

The following illustration includes the primary components of any off-grid battery-based microhydro-electric system..

picture...
 

Off-Grid Batteryless Microhydro-Electric Systems

If the stream has enough potential, one may decide to go with an AC-direct system. This consists of a turbine generator that produces AC output at 120 or 240 volts, which can be sent directly to standard household loads. The system is controlled by diverting energy in excess of load requirements to dump loads, such as water- or air-heating elements. This technique keeps the total load on the generator constant. A limitation of these systems is that the peak or surge loads cannot exceed the output of the generator, which is determined by the stream´s available head and flow. This type of system needs to be large to meet peak electrical loads, so it can often generate enough energy for all household needs, including water and space heating.

The following illustration includes the primary components of any off-grid batteryless microhydro-electric system.

picture ....


 

Grid-Tied Batteryless Microhydro-Electric Systems

Systems of this type use a turbine and controls to produce electricity that can be fed directly into utility lines. These can use either AC or DC generators. AC systems will use AC generators to sync directly with the grid. An approved interface device is needed to prevent the system from energizing the grid when the grid is out of action and under repair. DC systems will use a specific inverter to convert the output of a DC hydro turbine to grid-synchronous AC. The biggest drawback of batteryless systems is that when the utility is down, your electricity will be out too. When the grid fails, these systems are designed to automatically shut down.

The following illustration includes the primary components of any grid-tied batteryless microhydro-electric system.

 

[[|]]Microhydro-Electric System Components

Controls

AKA: Charge controller, controller, regulator

[[Image:|Controller]]

 

The function of a charge controller in a hydro system is equivalent to turning on a load to absorb excess energy. Battery-based microhydro systems require charge controllers to prevent overcharging the batteries. Controllers generally

send

excess energy to a secondary (dump) load, such as an air or water heater. Unlike a solar-electric controller, a microhydro system controller does not disconnect the turbine from the batteries. This could create voltages that are higher than some components can withstand, or cause the turbine to overspeed, which could result in dangerous and damaging overvoltages.

Off-grid, batteryless AC-direct microhydro systems need controls too. A load-control governor monitors the voltage or frequency of the system, and keeps the generator correctly loaded, turning dump-load capacity on and off as the load pattern changes, or mechanically deflects water away from the runner. Grid-tied batteryless AC and DC systems also need controls to protect the system if the utility grid fails.

Dump Load

AKA: diversion load, shunt load

[[Image:|Dump Load 1]][[Image:|Dump Load 2]]

A dump load is an electrical resistance heater that must be sized to handle the

full

generating capacity of the microhydro turbine. Dump loads can be air or water heaters, and are activated by the charge controller whenever the batteries or the grid cannot accept the energy being produced, to prevent damage to the system. Excess energy is "shunted" to the dump load when necessary.

 

 

Battery Bank

AKA: storage battery

[[Image:|Battery Bank]]

By using reversible chemical reactions, a battery bank provides a way to store surplus energy when more is being produced than consumed. When demand increases beyond what is generated, the batteries can be called on to release energy to keep your household loads operating.

A microhydro system is typically the most gentle of the RE systems on the batteries, since they do not often remain in a discharged state. The bank can also be smaller than for a wind or PV system. One or two days of storage

is

usually sufficient. Deep-cycle lead-acid batteries are typically used in

these

systems. They are cost effective and do not usually account for a large percentage of the system cost.

 

Metering

AKA: battery monitor, amp-hour meter, watt-hour meter

[[Image:|Metering]]

System meters measure and display several different aspects of your microhydro-electric system´s performance and status—tracking how full your battery bank is, how much electricity your turbine is producing or has produced, and how much electricity is being used. Operating your system without metering is like running your car without any gauges—although possible to do, it´s always better to know how well the car is operating and how much fuel is in the tank.

 

[[|]]Main DC Disconnect

AKA: Battery/Inverter disconnect

[[Image:|Main DC Disconnect]]

In battery-based systems, a disconnect between the batteries and inverter is required. This disconnect is typically a large, DC-rated breaker mounted

in a

sheet-metal enclosure. It allows the inverter to be disconnected from the batteries for service, and protects the inverter-to-battery wiring against electrical faults.

 

 

Inverter

AKA: DC-to-AC converter

[[Image:|Battery-Based Inverter]]Inverters transform

the DC electricity stored in your battery bank into AC electricity

for powering household appliances. Grid-tied inverters synchronize the system´s output with the utility´s AC electricity, allowing the system to feed hydro-electricity to the utility grid. Battery-based inverters for off-grid or grid-tied systems often include a battery charger, which is capable of charging a battery bank from either the grid or a backup generator if your creek isn´t flowing or your system is down for maintenance.

In rare cases, an inverter and battery bank are used with larger, off-grid AC-direct systems to increase power availability. The inverter uses the AC to charge the batteries, and synchronizes with the hydro-electric AC supply to supplement it when demand is greater than the output of the hydro generator.

[[|]]AC Breaker Panel

AKA: mains panel, breaker box, service entrance

[[Image:|AC Breaker Panel]]

The AC breaker panel, or mains panel, is the point at which all of a home´s electrical wiring meets with the provider of the electricity, whether that´s the grid or a microhydro-electric system. This wall-mounted panel or box is usually installed in a utility room, basement, garage, or on the exterior of a building. It contains a number of labeled circuit breakers that route electricity to the various rooms throughout a house. These breakers allow electricity to be disconnected for servicing, and also protect the building´s wiring against electrical

fires. 

Just like the electrical circuits in your home or office, a grid-tied inverter´s electrical output needs to be routed through an AC circuit breaker. This breaker is usually mounted inside the building´s mains panel. It enables

the

inverter to be disconnected from either the grid or from electrical loads if servicing is necessary. The breaker also safeguards the circuit´s electrical wiring.

 

[[|]]Kilowatt-Hour Meter

AKA: KWH meter, utility meter

[[Image:|Kilowatt-Hour Meter]]

Most homes with grid-tied microhydro-electric systems will have AC electricity both coming from and going to the utility grid. A multichannel KWH meter keeps track of how much grid electricity you´re using and how much your RE system is producing. The utility company often provides intertie-capable meters at

no

cost.

 

 

 

 

 

 

'Turbines'types

[[Image:]]

A turbine converts the energy in falling water into shaft power. There are various types of turbine which

can be

categorised in one of several ways. The choice of turbine will depend mainly on the pressure head available and the design flow for the proposed hydropower installation. As shown in table 2 below, turbines are broadly divided into three groups; high, medium and low head, and into two categories: impulse and reaction.


Turbine

Runner

Head

pressure

High

Medium

Low

Impulse

Pelton

Turgo

Multi-jet Pelton

Crossflow

Turgo

Multi-jet Pelton

Crossflow

Reaction

Francis

Pump-as-turbine (PAT)

Propeller

Kaplan

 

 

The difference between impulse and reaction can be explained simply by stating that the impulse turbines convert the kinetic energy of a jet of water in air into movement by striking turbine buckets or blades - there is no pressure reduction as the water pressure is atmospheric on both sides of the impeller. The blades of a reaction turbine, on the other hand, are totally immersed in the flow of water, and the angular as well as linear momentum of the water is converted into shaft power - the pressure of water leaving the runner is reduced to atmospheric or lower.

Load factor

The load factor is the amount of power used divided by the amount of power that is available if the turbine were to be used continuously. Unlike technologies relying on costly fuel sources, the 'fuel' for hydropower generation is free and therefore the plant becomes more cost effective if run for a high percentage of the time. If the turbine is only used for domestic lighting in the evenings then the plant factor will be very low. If the turbine provides power for rural industry during the day, meets domestic demand during the evening, and maybe pumps water for irrigation in the evening, then the plant factor will be high.

It is very important to ensure a high plant factor if the scheme is to be cost effective and this should be taken into account during the planning stage. Many schemes use a 'dump' load (in conjunction with an electronic load controller - see below), which is effectively a low priority energy demand that can accept surplus energy when an excess is produced e.g. water heating, storage heaters or storage cookers.

Load control governors

Water turbines, like petrol or diesel engines, will vary in speed as load is applied or relieved. Although not such a great problem with machinery which uses direct shaft power, this speed variation will seriously affect both frequency and voltage output from a generator. Traditionally, complex hydraulic or mechanical speed governors altered flow as the load varied, but more recently an electronic load controller (ELC) has been developed which has increased the simplicity and reliability of modern micro-hydro sets. The ELC prevents speed variations by continuously adding or subtracting an artificial load, so that in effect, the turbine is working permanently under full load. A further benefit is that the ELC has no moving parts, is very reliable and virtually maintenance free. The advent of electronic load control has allowed the introduction of simple

and

efficient, multi-jet turbines, no longer burdened by expensive hydraulic governors. 


Controller:

Function

Elements of a Micro Hydro Power Scheme
principles


Load- or Flow- controller ensure that the power output does not exceed the power demand (e.g. 230V, 50 Hz).
If flow of water in a MHP-station is constant the energy output of a turbine/generator is constant as well. Power demand is usually fluctuating over the time (e.g. day/night). If supply is higher than demand, excess energy must be diverted, dumped. alternatively the water flow can be reduced which results in less power output.
In case of more power demand than supply the controller cuts of the of demand line.
Load controller are placed between generator output and the consumer line.






Controller Types

Load controller:

Controler.jpg

Electronic circuit, which keeps output power constant in Frequency- and Voltage- parameters.

Fluctuating energy demand requires a mechanism which either regulates the water input into the turbine (= flow control) or by diverting excess energy from the consumer connection (= ballast load).

Ballast load

usually electrical heaters in water or air. If energy demand is temporarily low the excess energy is converted into heat.

Flow control

regulates the amount of water into the turbine in order to match power output and power demand.

Nowadays flow control is done mostly via electronics (which steer a valve)

principle flow control