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

0 4 8 12 16

Circuit Design

Proposed ELC Design Simulations

Alternative ELC Design Proposal

Analysis of Existing ELC Designs

Micro-hydro System Analysis

Micro-hydro Background Research

Week

MiniMini--project 1 project 1

Jon and Jon and ShoanShoan

MiniMini--project 2 project 2

ShoanShoan

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

• Minimal harmonics

– Disadvantages

• Fixed dump load sizes

• Requires large

number of dump

loads

• Effectiveness limited

by number of dump

loads

(Po

rte

gij

s, 2

00

0)

(He

nd

ers

on

, 1

99

8)

Phase Angle Regulation

– Advantages

• Can use any

number/size

combination of

dump loads

– Disadvantages

• Harmonics

• Effectiveness limited

by timing accuracy

of trigger pulse

(Po

rte

gij

s, 2

00

0)

(Po

rte

gij

s, 2

00

0)

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

0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000-0.5

0

0.5

1

1.5

2

2.5x 10

4 Binary Dump Load Power

Time (s/10000)

Pw

r (k

W)

0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000-2000

0

2000

4000

6000

8000

10000

12000User Load Pwr

Time (s/10000)

Pw

r (k

W)

0 1000 2000 3000 4000 5000 6000 7000 8000 9000 1000050

52

54

56

58

60

62System Frequency

Fre

quency (

Hz)

Time (s/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

0 2000 4000 6000 8000 10000 12000 14000 16000 180000

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08Variable Load Power

Pw

r (W

)

Time s/10000

Example 2

• User Load power

10.4kW + Binary Load

power 14kW= 24.4kW

• Surplus Power 600W

• System frequency =

61Hz

• Binary Load selection

of 8kW, 4kW, 2kW

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2

x 104

-2000

0

2000

4000

6000

8000

10000

12000User Load Power

Pw

r (W

)

Time

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2

x 104

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2x 10

4

Time

Pw

r (k

W)

Binary Load Dump Power

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2

x 104

50

52

54

56

58

60

62System Frequency

Fre

quency (

Hz)

Time

Example 3

0 1000 2000 3000 4000 5000 6000 7000 8000 9000 1000050

52

54

56

58

60

62System Frequency

Fre

quency (

Hz)

Time (s/10000)

• User Load power

10.4kW + Binary Load

power 14kW= 24.4kW

• Surplus Power 600W

• Variable Load power =

600W

• System frequency =

50Hz

• Binary Load selection

of 8kW, 4kW, 2kW

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2

x 104

-2000

0

2000

4000

6000

8000

10000

12000User Load Power

Pw

r (W

)

Time

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2

x 104

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2x 10

4

Time

Pw

r (k

W)

Binary Load Dump Power

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2

x 104

0

100

200

300

400

500

600

700Variable Load Power

Pw

r (W

)

Time

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