Download Isolated electric power systems reliability and efficiency

Isolated electric power systems reliability and
efficiency improvement based on electric power
quality monitoring and control
Project supervisor: Edward Szmit
Presenter: Daniel Czarkowski
Polski Rejestr Statków S.A.
Electrical and Automation Department
Gdańsk, POLAND
Conference “Aeronautics and surface transport days”
11-12 April 2005, Warsaw
© 2005 PRS S.A.
Ship electric power system
2
© 2005 PRS S.A.
Electromagnetic disturbances in a
ship’s power network
460
440
U [V]
420
Un=11%
400
380
0
1
2
3
4
time [min.]
61
fn=1,6%
60.5
f [Hz]
60
59.5
59
0
1
2
3
4
time [min.]
3
© 2005 PRS S.A.
Voltage distortion
400
Un=220 V
Total
Harmonic
Distortion
300
200
100
U [V]
0
-100
THD=4,4%
-200
-300
-400
time [s]
800
Un=440 V
600
400
200
U [V]
THD=13,5%
0
-200
-400
-600
-800
time [s]
How to measure power quality?
4
© 2005 PRS S.A.
From deviations to losses
human lives at risk
economical losses
danger of pollution
disturbances
in power
network
perturbs of
devices
failure
hazard conditions
on a ship
Effects of the occurrence of voltage and current higher
harmonics in electric power systems are as follows:




additional power losses in machines, transformers etc.,
additional power losses In capacitors and coils,
dropping accuracy of measuring instruments,
occurrence of mechanical vibrations.
What is the reason for calculating THD?
5
© 2005 PRS S.A.
Requirements

Classification societies:
THD
PRS
LR
DNV
ABS
GL
10%
8%
10%
5%
10%
International standard IEC 60092-101:2001
Electrical installations in ships - Part 101:
Definitions and general requirements:

–
–
–
–
THD
voltage deviations
frequency deviations
and other factors
≤ 5%
-10% +6%
±5%
Different requirements?
6
© 2005 PRS S.A.
Results of measurements
type of
parameter
THD required
by classification
societies
mean THD
measured on
a ship
maximum
THD
requirements
/ results
5-10%
12-19%
24%
Electronic power converters in power consumer system
are often installed on ships, e.g. Queen Mary II.
Ships’ main propulsion systems are more often electric.
Converters cause worse power quality.
Ship technology changes,
what about requirements?
© 2005 PRS S.A.
7
The aim of the project is realisation of ship’s
electric power systems based on a choice of
appropriate and effective technical solutions as
well as on elaboration of algorithms and
procedures of proceedings under hazard
conditions.
Thank you for your attention
Any further questions please contact me:
[email protected]
or project supervisor: [email protected]
© 2005 PRS S.A.