2. Introducing a Ship Electric Power Quality Monitoring System for Green Shipping

Introducing a Ship Electric Power Quality Monitoring System for Green Shipping

S. E. Dallas, A. D. Skoufis and J. M. Prousalidis School of Naval Architecture and Marine Engineering, National and Technical University of Athens sdallas@mail.ntua.gr XXIth International Conference on Electrical Machines Berlin, Germany – September 2-5, 2014

Topics of the presentation • Presentation of the DEFKALION-THALIS project • Introducing the Power Quality Monitoring System • Present the two examined cases and the specifications of the motor • Analyze the Current and Voltage waveforms • Analyze the Active and Reactive Power • Present the alterations in the Voltage and Current harmonics • Compare the voltage and current THD for the two examined cases • Conclusions XXIth International Conference on Electrical Machines Berlin, Germany – September 2-5, 2014

Presentation of the DEFKALION-THALIS project

Research Activities:

WP1: Project Management WP2: Investigation of PQ problems due to shaft generator operation WP3: Investigation of PQ problems due to thruster operation WP4: Investigation of PQ problems due to pod operation WP5: Analysis of impact of earthing (grounding) on PQ phenomena WP6: Analysis of PQ phenomena due to lightning strikes WP7: PQ Measuring and Monitoring System XXIth International Conference on Electrical Machines Berlin, Germany – September 2-5, 2014

Presentation of the DEFKALION-THALIS project

XXIth International Conference on Electrical Machines Berlin, Germany – September 2-5, 2014

Introducing the Power Quality Monitoring System

THE ELSPEC G4420 BLACKBOX

XXIth International Conference on Electrical Machines Berlin, Germany – September 2-5, 2014

Introducing the Power Quality Monitoring System

VOLTAGE MEASUREMENTS 5 Wire Terminals

3 for each phase R-S-T

1 Ground

XXIth International Conference on Electrical Machines Berlin, Germany – September 2-5, 2014

1 Neutral

Introducing the Power Quality Monitoring System

CURRENT MEASUREMENTS 6 Apertures (5 available – 1 disabled (No6))

3 for each phase R-S-T

1 Additional Current Input

XXIth International Conference on Electrical Machines Berlin, Germany – September 2-5, 2014

1 Neutral

Introducing the Power Quality Monitoring System

CURRENT MEASUREMENTS

Three current transformers (one for each phase) with a ratio of 250/1 are used.

Due to the potential development of high currents (i.e. transient inrush currents)

XXIth International Conference on Electrical Machines Berlin, Germany – September 2-5, 2014

Introducing the Power Quality Monitoring System

Topologies Available from ELSPEC

• • • •

Line to Neutral Single Line to Line configuration 2 phase TR connection Delta 3 wires (including Delta High Leg – Delta Open Leg) • WYE 4 Wires (including Three Wire WYE)

XXIth International Conference on Electrical Machines Berlin, Germany – September 2-5, 2014

Introducing the Power Quality Monitoring System

The Measurement System Topology

• Data acquisition was established through wireless communication.

• The ELSPEC devices have ethernet ports (wired communication), which were converted to wireless using a Wi-Fi-router.

XXIth International Conference on Electrical Machines Berlin, Germany – September 2-5, 2014

Introducing the Power Quality Monitoring System

The Measurement System Topology • The real-time monitoring and configuration is achieved via HTTP (web browser), while the acquisition of data is accomplished using PQSCADA software (acquires stored data using FTP).

• For the data acquisition and monitoring a small netbook was used, which was wirelessly connected to the router.

XXIth International Conference on Electrical Machines Berlin, Germany – September 2-5, 2014

Introducing the Power Quality Monitoring System

The Retrofitted System The full system topology of the Ventilation Fan

The wired communication of ELSPEC

XXIth International Conference on Electrical Machines Berlin, Germany – September 2-5, 2014

Present the two examined cases and the specifications of the motor

Specifications of the Ventilation Fan kW

V

A

Hz

OLD STARTER

NEW STARTER

11

440

22.3

60

D.O.L

VFD

XXIth International Conference on Electrical Machines Berlin, Germany – September 2-5, 2014

Analyze the Current and Voltage waveforms

The RMS values of the motor’s voltage.

The recording process of the ship’s electrical magnitudes lasted almost one month.

The period that no measurements are appearing, is the interval that the repairing procedure took place.

XXIth International Conference on Electrical Machines Berlin, Germany – September 2-5, 2014

Analyze the Current and Voltage waveforms The voltage waveform for the DOL operation

The voltage waveform for the VFD operation

The sampling of these measurements is 5 kHz The exact dates that these measurements were obtained are: 23/4/2013 at 12.00.00 for the DOL operation and on 23/5/2013 at 12.00.01 for the VFD operation.

XXIth International Conference on Electrical Machines Berlin, Germany – September 2-5, 2014

Analyze the Current and Voltage waveforms The current waveform for the DOL operation

The current waveform for the VFD operation

The VFD operation changes the current waveforms from sinusoidal to non-sinusoidal.

A significant 25% reduction of the current amplitude.

XXIth International Conference on Electrical Machines Berlin, Germany – September 2-5, 2014

Analyze the Active and Reactive Power  The presence of the VFD, reduces the active and reactive power, by almost 22% and 43% respectively.  The active power reduction influences the power consumption of this motor  The reactive power reduction decreases the respective reactive currents and losses, resulting in a more efficient operation of the ship electric grid.

XXIth International Conference on Electrical Machines Berlin, Germany – September 2-5, 2014

The Voltage and Current harmonics The voltage harmonics for the DOL operation

The voltage harmonics for the VFD operation

The voltage supply of the ventilation fan didn’t change No significant alterations in the harmonic content appeared.

XXIth International Conference on Electrical Machines Berlin, Germany – September 2-5, 2014

The Voltage and Current harmonics The current harmonics for the DOL operation

The current harmonics for the VFD operation

XXIth International Conference on Electrical Machines Berlin, Germany – September 2-5, 2014

The Voltage and Current harmonics • During the DOL operation there is a low 3rd and 5th harmonic of the current, as the current waveform looks almost pure sinusoidal. • The presence of the VFD caused the harmonic content to change.

The amplitude of the 5th and 7th harmonic has significantly increased. (the current amplitude decreased, but its waveform has been distorted, containing a significant amount of harmonics)

XXIth International Conference on Electrical Machines Berlin, Germany – September 2-5, 2014

The Voltage and Current harmonics

• The existence of the Variable Frequency drive decreases the power consumption of the motor • Increases the motor current harmonics • Increases the harmonic distortion of the current flowing in the entire electric grid

XXIth International Conference on Electrical Machines Berlin, Germany – September 2-5, 2014

The voltage and current Total Harmonic Distortion (THD) The voltage THD

THD (%) V12

V23

V31

DOL

0.18-1.7

0.15-2.0

0.19-1.8

VFD

0.5-2.6

0.7-2.7

0.65-2.8

The installation of the VFD results in a rise of the THD voltage varying between 35% and 78%.

This increment, in absolute numbers, remains within the permissible limits for the proper motor operation

XXIth International Conference on Electrical Machines Berlin, Germany – September 2-5, 2014

The voltage and current Total Harmonic Distortion (THD) The current THD

The Total Harmonic Distortion of the motor current have totally different behavior. • The non-sinusoidal waveforms of the current, produced by the VFD creates more harmonics

XXIth International Conference on Electrical Machines Berlin, Germany – September 2-5, 2014

The voltage and current Total Harmonic Distortion (THD) The current THD

The Total Harmonic Distortion of the motor current have totally different behavior. • The current fluctuations, also for the VFD operation

XXIth International Conference on Electrical Machines Berlin, Germany – September 2-5, 2014

The voltage and current Total Harmonic Distortion (THD) The current THD

The two time intervals (namely before and after the VFD installation)

• In the absence of the VFD, the RMS value of the motor current remains constant without any fluctuations.

• After the installation of the VFD, high fluctuations in current appear, while the current value (mean RMS value) is reduced by almost 33%.

XXIth International Conference on Electrical Machines Berlin, Germany – September 2-5, 2014

The voltage and current Total Harmonic Distortion (THD) The current THD

Interval 1: The DOL operation Intervals 2–3: The VFD operation.

XXIth International Conference on Electrical Machines Berlin, Germany – September 2-5, 2014

The voltage and current Total Harmonic Distortion (THD) The current THD

I1

THD (%) I2

I3

INTERVAL 1

0.1-0.9

0.1-0.75

0.1-0.9

INTERVAL 2

0.1-93

0.1-85

0.1-90

INTERVAL 3

44-54

43-53

44-54

The total harmonic distortion of the motor is increased by 440%.

XXIth International Conference on Electrical Machines Berlin, Germany – September 2-5, 2014

Conclusions

• The implementation of the monitoring system onboard during a full operational mode, provided interesting results concerning the motor performance • The installation of the VFD produced changes in the voltage and current waveforms. The current waveform is significantly distorted from the sinusoidal form, while the voltage waveform is subject to minor changes • No significant changes in the voltage harmonics appear, only a small rise of the 3rd voltage harmonic (VFD operation)

XXIth International Conference on Electrical Machines Berlin, Germany – September 2-5, 2014

Conclusions

• Important changes appears in the current harmonics. The 5th and the 7th harmonics are of significant high value in the presence of the VFD, while the 3rd harmonic measured in the DOL operation, is eliminated

• The voltage THD increased, but it remains within the permissible limits • There are noticeable rise in the current THD (VFD operation, steady state case)

XXIth International Conference on Electrical Machines Berlin, Germany – September 2-5, 2014

Acknowledgments

 The methodology presented in this paper has been developed within the framework of the Thales-DEFKALION project (www.defkalion-thalis.org). This research has been co-financed by the European Union (European Social Fund – ESF) and Greek national funds through the Operational Program "Education and Lifelong Learning" of the National Strategic Reference Framework (NSRF) - Research Funding Program: THALES: Reinforcement of the interdisciplinary and/or inter-institutional research and innovation

XXIth International Conference on Electrical Machines Berlin, Germany – September 2-5, 2014

Acknowledgments

 The authors gratefully acknowledge the contribution of Mr. S.V. Giannoutsos as long as the THENAMARIS Ships Management, for the opportunity provided to install the power quality monitoring system onboard one of their ships.

 The hospitality and support of all crew members of the THENAMARIS ship is gratefully acknowledged.

XXIth International Conference on Electrical Machines Berlin, Germany – September 2-5, 2014

Thank you very much for your attention!

XXIth International Conference on Electrical Machines Berlin, Germany – September 2-5, 2014