A Micro-hydro Electronic
Load Controller (ELC) for
the Developing World
Shoan Mbabazi
Overview
•
•
•
•
•
•
•
Aims and Objectives
Electronic Load Controllers (ELCs)
Existing ELC Designs
Proposed Design
Simulation Results
Conclusion
Continuing the Project
Project Outline
Mini-project 1
MiniJon and Shoan
Mini-project 2
MiniShoan
Micro-hydro Background Research
Micro-hydro System Analysis
Analysis of Existing ELC Designs
Alternative ELC Design Proposal
Proposed ELC Design Simulations
Circuit Design
0
4
8
Week
12
16
Aims and Objectives
• To design and construct an alternative
Electronic Load Controller (ELC) for use in
developing countries, with particular
emphasis on:
– Simplicity of Design
– Ease of Manufacture
– Robustness
– Ease of Maintenance
– Affordability
What is an ELC?
(RENERCONSYS, 2010)
What does an ELC do?
Power in = Power out
{(VinIincosθin)ηin} ={(VoutIoutcosθout)ηout}
V – Voltage, I – Current, Cosθ – Power Factor, η - Efficiency
(Ludens, 2010)
Existing ELC Designs
Existing ELC Design
• Binary load regulation.
• Phase angle regulation.
• Pulse width regulation.
• Controlled bridge rectifier.
• Uncontrolled rectifier with a chopper.
Binary Load Regulation
– Advantages
(Henderson, 1998)
• Minimal harmonics
• Fixed dump load sizes
• Requires large
number of dump
loads
• Effectiveness limited
by number of dump
loads
(Portegijs, 2000)
– Disadvantages
(Portegijs, 2000)
Phase Angle Regulation
– Advantages
• Can use any
number/size
combination of
dump loads
• Harmonics
• Effectiveness limited
by timing accuracy
of trigger pulse
(Portegijs, 2000)
– Disadvantages
Proposed ELC Design
• The proposed ELC uses the combination of
binary load and phase angle regulation
methods.
– Minimising the disadvantages presented by each
used on its own
Proposed ELC Operation Principle
Advantages of the Proposed ELC
• Less Dump loads can be used to cover a large
spectrum on load variations.
• Generator runs at a desired speed at all times.
• Minimal harmonics are injected into the system at
steady state
• Minimal power distortion at transient switching
periods
Simulations
• The simulations have been undertaken using a
computer simulation package MATLAB Simulink.
• A standalone micro-hydro system rated at 25kw,
230V 50Hz with,
• an ELC comprising of five binary dump loads (1kw,
2kw, 4kw, 8kw, 16kw) and a single 1kw variable
dump load
Simulink Model
Example 1
System Frequency
User Load Pwr
62
12000
10000
•
User Load power
10kW + Binary Load
power 15kW=
Generated Power
25kw
•
Variable Load power =
0W
•
System frequency =
50Hz
•
Binary Load selection
of 8kW, 4kW, 2kW,
1kW
60
8000
Frequency (Hz)
4000
56
54
2000
52
0
-2000
50
0
2.5
1000
x 10
2000
4
3000
4000 5000 6000
Time (s/10000)
7000
8000
9000 10000
0
1000
2000
3000
Binary Dump Load Power
4000 5000 6000
Time (s/10000)
7000
8000
9000 10000
Variable Load Power
0.08
0.07
2
0.06
1.5
Pwr (W)
0.05
Pwr (kW)
Pwr (kW)
58
6000
1
0.04
0.03
0.5
0.02
0
0.01
-0.5
0
1000
2000
3000
4000 5000 6000
Time (s/10000)
7000
8000
9000 10000
0
0
2000
4000
6000
8000 10000
Time s/10000
12000
14000
16000
18000
Example 2
User Load Power
12000
•
User Load power
10.4kW + Binary Load
power 14kW= 24.4kW
•
Surplus Power 600W
•
System frequency =
61Hz
•
Binary Load selection
of 8kW, 4kW, 2kW
10000
6000
System Frequency
4000
62
2000
60
0
0
0.2
0.4
0.6
4
2
0.8
1
Time
1.2
1.4
1.6
1.8
2
4
x 10
Binary Load Dump Power
x 10
Frequency (Hz)
58
-2000
56
54
1.8
1.6
52
1.4
50
1.2
Pwr (kW)
Pwr (W)
8000
1
0.8
0.6
0.4
0.2
0
0
0.2
0.4
0.6
0.8
1
Time
1.2
1.4
1.6
1.8
2
x 10
4
0
0.2
0.4
0.6
0.8
1
Time
1.2
1.4
1.6
1.8
2
4
x 10
Example 3
System Frequency
User Load Power
•
62
12000
10000
60
8000
Frequency (Hz)
4000
•
56
54
2000
52
0
-2000
50
0
0.2
0.4
0.6
4
2
0.8
1
Time
1.2
1.4
1.6
1.8
2
0
1000
2000
3000
4
7000
8000
•
Variable Load power =
600W
•
System frequency =
50Hz
•
Binary Load selection
of 8kW, 4kW, 2kW
9000 10000
Variable Load Power
Binary Load Dump Power
x 10
4000 5000 6000
Time (s/10000)
x 10
700
1.8
600
1.6
500
1.4
Pwr (W)
1.2
Pwr (kW)
Pwr (W)
58
6000
User Load power
10.4kW + Binary Load
power 14kW= 24.4kW
Surplus Power 600W
1
400
300
0.8
200
0.6
0.4
100
0.2
0
0
0
0.2
0.4
0.6
0.8
1
Time
1.2
1.4
1.6
1.8
2
4
x 10
0
0.2
0.4
0.6
0.8
1
Time
1.2
1.4
1.6
1.8
2
4
x 10
Proposed ELC Design Specification
– Maintains constant frequency/Voltage.
– Robust and Affordable.
– Digital
Minimal components
Easy to install
Synchronous/asynchronous
50/60 Hz
Single/3-phase
Conclusion
• The proposed ELC is:
–
–
–
–
Simple
Reliable
Injects fewer harmonics than phase angle alone.
Less dump loads are required compared to Binary
regulation alone.
– Improves system efficiency.
Higher the efficiency reduces energy prices.
Continuing the Project
Questions....?
References
[1] A. Harvey, Micro-hydro Design Manual. Rugby: Intermediate Technology
Publications, 2006.
[2] H. Ludens. (2010, Electronic Load Controller for microhydro system.
Available: http://ludens.cl/
[3] J. Portegijs. (2000, 6 December ). The `Humming Bird' Electronic Load
Controller / Induction Generator Controller.
[4] Renerconsys, "Digital Load Controller for Synchronous Generator: Manual
Instruction," 2010.
[5] D. Henderson, "An Advanced Electronic Load Governor for Control of
Micro Hydroelectric Generation”, 1998
[6] Spirax Sarco, “Basic Control Theory”, 2010. Available:
www.spiraxsarco.com