JMAAA Seminar

December 22, 2015 – Dhaka

A lively seminar on shipboard electric system was held at JMAAA Dhaka offices. Highlights of the seminar are as follows:

Subject: Shipboard high voltage power

1. Shipboard electrical blackout recovery

1. Shipboard electrical redundancy, ship service and propulsion power
2. Shipboard electrical propulsion including azipod
3. HV and LV electrical grounding challenge and mitigation

Presented by:

Mohammed Monirul Islam, 4^th Batch Engg. Juldia Marine Academy, Chittagong, Bangladesh

Retired shipboard Electrical System Design Engineer.

Author of “ Handbook to IEEE Standard-45: Recommended practice for Shipboard Electrical Installations”.

Retired Chairman of IEEE-45 Standard Development.

COPY RIGHT-MMISLAM

AT THE RANGE OF 100MEGAWATT POWER GENERATION AND DISTRIBUTION

ADAPTED EXAMPLE : GROUNDING-SHIPBOARD SMART AND SAFE SYSTEM

TOPICS

1. FUNDAMENTALS OF SHIPBOARD GROUNDING
2. FUNDAMENTALS OF GS4-SHIPBOARD SMART AND SAFE GROUNDING SYSTEM
3. EXAMPLES OF CONVENTIONAL SHIPBOARD POWER LEVEL GROUNDING
4. CHALLENGES OF SHIPBOARD CONVENTIONAL GROUNDING OPTIONS OF MITIGATING CONVENTIONAL GROUNDING CHALLENGES
5. RECOMMENDATIONS FOR ADAPTING SHIPBOARD SMART AND SAFE GROUNDING AND MONITORING SYSTEM
6. ARC FLASH CHALLENGES-BETTER SYSTEM COORDINATION
7. ROLE OF IEEE-45 STANDARD DEVELOPING WORKING GROUP FOR GS4
8. ROLES OF -INDUSTRY, UNIVERSITY AND RESEARCH GROUP FOR GS4

GOAL– UNDERSTANDING OF SHIPBOARD GROUND DETECTION SYSTEM OF UNGROUNDED POWER GENERATION AND DISTRIBUTION FUNDAMENTALS OF SHIPBOARD GROUNDING

*  SHIPBOARD POWER GENERATION AND DISTRIBUTION SYSTEM IS ISOLATED OR UNGROUNDED

*  CAPACITIVE SYSTEM GROUNDING

*  GROUND DETECTION SYSTEM HAS BEEN WITH LIGHTS AND TEST PUSHBUTTONS

* ADVENT OF MEDIUM VOLTAGE POWER GENERATION AND DISTRIBUTION BROUGHT ALONG RESISTANCE GROUNDING

*  THIS RESISTIVE GROUNDING AS WELL AS GROUND DETECTION LIGHTS CREATED CONFUSION DUE TO THE FACT THE RESISTANCE GROUNDING ALLOWS UP 5 AMPS (HRG) TO THE GROUND.

*  THIS RESISTIVE GROUNDING MAY COMPROMISE ELECTRICA SAFETY ONBOARD SHIP.

*  THEREFORE THE SAFETY AND RELIABILITY ISSUES MUST BE ADDRESSED PROPERLY

*  UNDERSTAND REGULATORY BODY REQUIREMENTS

• BY REGULATION ELECTRICAL POWER DISTRIBUTION SYSTEM MUST BE GROUNDED
• BY REGULATION SHIPBOARD POWER SYSTEM MUST NOTBE GROUNDED
• SHIPBOARD UNGROUNDED SYSTEM IS REALLY

CAPACITIVE GROUNDED

• RECENTLY RESISTANCE GROUNDING SYSTEM HAS BECOME A NORM FOR SHIPBOARD POWER SYSTEM•

EXPERT OPINION

“UNGROUNDED” SYSTEMS

REALLY ARE GROUNDED ON SHIPS

*  Ungrounded voltage systems are usually selected for “no- break” voltage systems, where power cannot be lost without endangering life or property

*  Ship power systems are usually ungrounded, with no direct earthing connection

*  Such systems are actually grounded via cable capacitance, and may be resistance or impedance grounded to protect equipment.

*  Electronics equipment using line filters – common mode

capacitors add to system capacitance

The seminar started at 12 noon and ended at about 5 PM. There were Questions and Answers (Q&A) and informal discussion. A lunch was also arranged in between.

Some photos of the event: