EMC/EMI for Shipbuilding

EMC/EMI for Shipbuilding

EMC/EMI for Shipbuilding, is an Intermediate and Advanced EMI/EMC training course for Shipbuilding. This  course explores the fundamental concepts of electromagnetic compatibility/electromagnetic interference (EMC/EMI).

Electromagnetic Interference (EMI) refers to unwanted effect of EM noise interfering with our signals.

Participants will learn about the electromagnetic (EM) environments and the requirements commercial and military Shipbuilding equipment and electronic systems must meet. Other topics discussed are E3, EFT, EMP, HIRF, ESD, P-STATIC, unconventional high-power EM threats, including nuclear electromagnetic pulse (EMP) and high-power microwave (HPM) weapons.

Electromagnetic Compatibility (EMC) refers to EM compatibility means the ability of equipment to function satisfactorily in its EM environment without introducing intolerable EM disturbances to other equipment in that environment. Products shall not be susceptible, or in other words, shall be immune to electromagnetic interference such as Electrical Fast Transients (EFT) and Electrostatic Discharge (ESD) and furthermore, systems may be required to operate in severe electromagnetic environments such as during lightning strikes, and withstand threats such as electromagnetic pulses (EMP).

Electronic systems may be susceptible to damaging Electromagnetic Environmental Effects (E3) that can arise from a variety of natural or man-made environmental sources.

These sources may include Electromagnetic Pulse (EMP), Radio Frequency Interference (RFI), High Intensity Radiated Fields (HIRF), Electromagnetic Interference (EMI), Electrostatic Discharge (ESD), Lightning Strikes and Precipitation Static (P-STATIC).

Who Should Attend

This course is designed for engineers, technicians, analysts, testers, acquisition, and engineering managers involved in planning, designing, implementation and maintaining commercial or military shipbuilding industry related to electronic system design, radar, communication systems.

Course Agenda

INTRODUCTION TO EMI AND EMC

• Basic EMI/EMC
• EMI/EMC definitions and key concepts
• EMI/EMC requirements, specifications and standards
• EMC risk analysis
• EMC design and mitigation techniques
• EMC troubleshooting
• Core Principles of Electromagnetic Fields, Coupling and Radiation
• The Nature of Electromagnetic Interference, EMI
  • Sources/Emitters/Radiators as Threats
  • Coupling Mechanisms/Paths
  • Receptors/Victims — susceptibility, immunity
• Principles of Electromagnetic Compatibility (EMC)
• E3 (Electro-Environmental Effects)
• EFT (Electrical Fast Transients)
• ESD (Electrostatic Discharges)
• EMP (Electromagnetic Pulses)

IDENTIFICATION OF APPLICABLE STANDARDS

• Applicable Military and Defense Standards, handbooks
• Corresponding International and Civilian Standards
• Safety Standards: Human Exposure (HERP), HERO, HERF

TYPES OF ELECTROMAGNETIC COUPLING

• Inductive and Capacitive Coupling
• Common-Impedance Coupling
• Radiated RF Coupling

EMI CATEGORIES OF CABLES and THEIR VULNERABILITIES

• Table and descriptions, examples of each (R1…R9, S3…etc. complete)
• Normal Cable standoff distances between categories
• Power-cable-specific considerations
  • Power cables as victims – effects of near and far-field coupling
  • What levels of RF fields would degrade or damage cables? EMP?
  • What methods could reduce effects of high strength fields?
• Signal-cable-specific considerations (defined as carrying 4-20 ma)
  • Differential vs. Common mode coupling
  • Cable-as-victim: near field vs far field effects, coupling
  • Digital-vs-Analog signals: logic vs analog vulnerabilities
  • What field strength levels could degrade or damage cable?
  • What methods could reduce the effects of high-strength fields?

INDUCTIVE AND CAPACITIVE COUPLING

• Current in one conductor inducing current in nearby conductor

• • Coupling magnitude influences – loop area, field intensity
  • Magnetic shielding materials and practical characteristics
  • Difficulty of effective magnetic shielding

• Voltage on one conductor capacitively couples voltage to a nearby conductor

• • Capacitive (electrostatic) shielding of conductors
  • Shield types and effects over different frequencies
  • Electrostatic Shielding materials and practical characteristics

COMMON-IMPEDANCE COUPLING AND EFFECTS

• Current in a shared conductor creates voltage drop seen by both circuits
• Voltage on a Current in one conductor induces current in nearby conductor
• Circuit reference points – what is the effective input point? What are the nodes between which the interference directly appears

RADIO-FREQUENCY RADIATION COUPLING

• RF current flowing in a conductor (“transmitting antenna”) radiates a combined electromagnetic field
• Electromagnetic field surrounding a conductor (“receiving antenna”) induces voltage and current in it
• The effect of wavelength in determining what coupling occurs
• Types of fields and coupling encountered in Near-field and Far-field conditions
• Coupling into conducting structures – boxes, enclosures, with openings of any type

SHIELDING EFFECTS, METHODS AND MATERIALS

• Electrostatic Shielding
• Magnetic Shielding
• Shielded Cables
• Plane-Wave shielding, Near-field shielding
• What are the purposes/effects of shields – inner vs outer?
• Shielded Enclosures

GROUNDING, BONDING, AND OTHER TECHNIQUES

• Bypassing, decoupling, and grounding
• Bonding or Grounding against what?
• What does “ground” mean? Where is it? Can it be extended by cable?
• Can grounding or bonding actually worsen problems?
• Separation of Signal and Power Grounds
• Avoiding Ground Loops
• Single-point and multi-point grounds
• EMI Gasketing
• EMI Stuffing Tubes

PRINCIPLES OF CIRCUIT ARRANGEMENT TO MINIMIZE EMI

• Controlling EMI among conductors, chassis, and enclosures
• Grouping and Isolating incompatible conductors
• Design of circuit boards to minimize EMI coupling

DIFFERENTIAL AND COMMON MODE CIRCUITS

• Differential circuits – what is a differential output or input?
• Why differential signal circuits are so effective
• Maintaining isolation of differential circuits from common mode signals
• Methods of coupling – transformer, optical, differential amplifiers
• Common mode rejection: how specified, how measured
• Effects of Non-linear devices in differential circuits

NOISE AND SPECIAL TYPES OF INTERFERING SIGNALS

• Thermal Noise
• Noise from power supplies, other subsystems
• Component noise and “chatter”
• Harmonics of AC power frequencies and RF fields
• Arcs and Transients
• Non-linear effects – inductor saturation, amplifier non-linearities
• Intermodulation – active and passive

RADIATION HAZARDS AND SAFETY OF HUMANS AND EQUIPMENT

• The nature of radiation effects on exposed objects
• Ionizing and Non-Ionizing radiation
• Human radiation safety standards
• HERP – Hazards of Electromagnetic radiation to Personnel
• HERO – Hazards of Electromagnetic radiation to Ordnance
• HERF – Hazards of Electromagnetic radiation to Fuel
• Radiation calculation methods
• Radiation measurement methods
• Effects of Bulkheads, Shielding, Standoffs
• Defining areas requiring protection
• Operations procedures for protection

RADAR CONSIDERATIONS

• Radar signal waveforms, powers, and spectra
• Radar signal propagation, losses, power and sensitivity requirements
• Special interference considerations to and from radars
• Reflecting objects and their effectiveness in reflecting radar signals
• Calculating and measuring effective radar “cross-section” of objects
• Techniques used to minimize radar “cross-section”