Haliade-X High Voltage AT2 Familiarization Flashcards

Haliade-X High Voltage Operating Objectives

• Upon completion of the Electrical Safety Program (ESP) training, personnel must demonstrate an understanding of switching operations and the necessity behind them.

• Individuals must achieve confidence in interpreting the Single Line Diagram (SLD) specific to the Haliade-X turbine.

• Clear expectations must be met when executing switching operations, including understanding the capabilities and limitations of different types of switchgear encountered on the Haliade-X.

• Participants must understand why High Voltage (HV) Approved Written Procedures (AWPs) are required and how they are structured.

• A critical requirement is knowing the exact conditions under which an operation must be stopped to seek additional support.

Roles and Responsibilities in the Electrical Safety Program

The Authorised Technician 2 (AT2)

• Documentation and RAMS: The AT2 is responsible for checking and ensuring satisfaction with the Risk Assessment Method Statements (RAMS) and ensuring the issued GE Offshore Wind (OFW) safety document is robust for the work to be performed safely.

• General Safety Conditions: They must verify that general safety conditions are suitable before commencing work.

• Live Work Prohibition: The AT2 must ensure that no repair work is carried out live under operating voltages.

• Pre-Task Briefing: Before work begins, the AT2 must deliver the turbine pre-task briefing to the Working Party, covering:

  • Hazards and control measures, including shock approach boundaries and arc/flame protective Personal Protective Equipment (PPE).

  • Requirements for the use of approved insulated tools.

  • The method of work and safety precautions, limitations, or cautions specified in the safety document.

  • Notification of adjacent live equipment.

• Safety Maintenance: They must apply and maintain safety precautions during the work and ensure correct supervision levels.

• Accompanying Technician: They must brief the accompanying technician on hazards, work requirements, and emergency response, specifically electrical disconnection procedures.

• Bystander Safety: Other working parties near the work area must be warned of safety distances, PPE requirements, and shock/arc flash boundaries.

• Equipment Inspection: Visually inspect approved insulated tools and PPE before use. Test instruments must have an in-date calibration certificate.

Safety Document Issuing Authority

• Responsible for establishing and verifying HV isolations and earthing.

• Issues and signs on to AE2 pre-written GE OFW safety documents at the point of work after isolation verification.

• Conducts point-of-work Toolbox Talks (TBT) regarding precautions.

• Transfers immediate supervision responsibility to the AT1 in charge of the work party.

• Verifies the work area and HV equipment are safe before return to service and cancels safety documents after completion.

Supervisor or Nominated Authorised Technician

• Responsible for selecting an AT to carry out work and an appropriately trained accompanying technician.

• Grants permission for HV work by releasing the appropriate safety document.

• Ensures availability of temporary signage and barriers for establishing portable test areas during HV testing.

• Agrees on forward planning of HV work with the Operational Controller.

Authorised Engineer 2 (AE2)

• Justifies the requirement for live testing through risk assessment before approving a Sanction for Test.

• Ensures no safety document is approved that requires live repair work under operating voltage.

• Defines safety precautions for adjacent exposed live equipment.

• Maintains a comprehensive list of GE OFW HV safety documents for each site or project.

Remote Operations Center (ROC) Roles

• ROC 1:

  • Safely operates HV equipment from the ROC when instructed by an AT2 for functional switching or safety achievement.

  • Operates equipment when requested by an AT1 to prevent nuisance tripping.

  • Handles pre-approved Fault Handling Procedures to re-energize turbines after fault trips.

  • Recovers healthy turbines after grid outages and carries out pre-operation checks.

  • Monitors HV systems and logs all operations, alarms, and alerts.

• ROC 2:

  • Includes all ROC 1 responsibilities.

  • Interrogates HV systems for fault finding outside standard procedures.

  • Operates or instructs the operation of HV equipment on unoccupied turbines.

High Voltage Switchgear Definitions and Equipment

HV Thresholds

• High Voltage switchgear is identified as any switchgear operating at voltages above $1000\,V$ AC and $1500\,V$ DC.

Common Haliade-X HV Equipment

• Circuit Breakers and Disconnecting Circuit Breakers.

• Disconnectors and Earth Switches.

• Protection Relays and Converters.

• Transformers and High Voltage Cables.

• Fuses and Generators.

Circuit Breakers (CB)

• Used to make or break circuits under fault or load conditions.

• Insulating Mediums:

  • Air (ACB).

  • $SF_6$ or Gas Insulated (GIS).

• Haliade-X Specifics: Contains two air-insulated circuit breakers (GRB CB1 and GRB CB2) located in the converters.

• Capabilities:

  1. Operable under load.

  2. Offers fault protection.

  3. Limitations: Does not provide sufficient separation to be used as a Point of Isolation (PoI).

Disconnectors

• Used to provide physical and securable separation to allow for isolation.

• Restrictions: Generally cannot be operated under circuit load.

• Three-Position Disconnectors: Found on the Haliade-X, featuring:

  1. Disconnector Closed / Earthing Switch Open.

  2. Disconnector Open / Earthing Switch Open.

  3. Disconnector Open / Earthing Switch Closed.

• Naming Conventions:

  • $Q11$: Transition between Open and Closed.

  • $Q51$: Transition between Open and Earth.

• Capabilities:

  1. Not operable under load.

  2. No fault protection.

  3. Used as a Point of Isolation (PoI).

Disconnecting Circuit Breakers (DCB)

• Combines functions: makes/breaks under fault or load and provides the physical separation required for a PoI.

• Haliade-X Specifics: Found in the GIS.

  • $Q01$: Primary protection for $66\,kV$ incoming grid feed; used to isolate supply to the main transformer.

  • $Q03$: Used only for the End of Line (EoL) HV Filter.

Earth Switches and Earthing Systems

• Creates a short circuit to earth to make equipment safe for access by bringing it to ground potential. Usually applied with a disconnector to ensure the absence of load/voltage.

• Primary Earth: Must have a cross-sectional area capable of withstanding inadvertent energization for $2\,seconds$ to allow protection equipment to operate.

• Drain Earth: A fixed or portable device used to protect against induced voltages, impressed voltages, or back-feed.

• Placement: Primary earths must be within the isolated zone between the work point and all points of isolation (excluding LV connections but including common neutral earthing).

Protection Systems and Transformers

HV Protection Relay (F650)

• Complies with Electricity at Work Regulations 1989, Regulation 11 regarding protection from excess current.

• Fault Detection: Over/Under Voltage, Over/Under Frequency, Earth Faults, and Overcurrents.

• Overcurrent Protection Types:

  • Instantaneous: Operates immediately (with a few milliseconds inherent delay) when current exceeds the preset value.

  • Definite Time: Operates only if the fault exceeds the current setting and persists for the preset time delay.

  • Inverse Time: Operating time is inversely proportional to the current (high current triggers faster operation).

Transformer Specifications

• Haliade-X Transformer Units:

  1. Service Voltage Transformer (T6/SVT): $66\,kV/400\,V$ ($SF_6$ insulated).

  2. Voltage Transformer (T5): $66\,kV/110\,V$ ($SF_6$ insulated).

  3. Main Transformer: $66\,kV/3.1\,kV/3.1\,kV$ (Oil insulated).

  4. Auxiliary Transformer: $66\,kV/400\,V$ (Oil insulated).

  5. Pre-charge Transformer: $400\,V/4.9\,kV$ (Air insulated).

• Monitoring Features: Buchholz Relays (Tank and Conservator), Oil Level Indicator, MV Fuses, Oil Temperature Thermometer, Pressure Relief Device, and Leakage Relay.

Operational Procedures and Communication

Communication Standards

• Clarity: Use easy-to-understand language and agreed terminology.

• Repeat-Back Procedure: The receiver must repeat information back; the sender confirms, then the action is completed.

• Phonetic Alphabet: Used to prevent miscommunication of complex wording.

• Agreed Terms:

  • Open / Off: Breaks/provides separation of the circuit.

  • Close / On: Completes/makes the circuit connection.

  • Earth / Ground: Connection to a protective earth conductor.

Requirements for AT2 Switching

• Operations must be deliberate, without rushing or undue delay.

• The AT2 must have the GE OFW safety document/Switching Schedule present.

• They must pause to check equipment identity and consider consequences before acting.

• The switchgear must be visually inspected for dielectric gas pressure sufficiency.

• Any abnormalities require immediate work stoppage and reporting to the AE2.

• Safety locks must be applied immediately after operation.

Interrupted and Continuous Operations

• Continuous: For three-position disconnectors moving directly from open to earth (or vice versa), visual confirmation is required for each step, and locks are not required during the transition.

• Interrupted: If other isolations must be done between opening a disconnector and earthing, the disconnector must be locked with a safety lock in the interim.

Hierarchy of Operations

1. ROC (Remote).

2. N/A (Haliade-X).

3. Handheld device with long lead.

4. LCC (F650 Control).

5. Manual operating facilities.

Emergency Switching

• Permitted only if the person understands the desired outcome and has sufficient knowledge.

• Allowed for: imminent risk to life, immediate danger to plant (fire/explosion), or preventing fault escalation.

• The AE2 and Operational Controller must be notified immediately afterward.

Safety Documentation and the DIESR Principle

Types of Safety Documents

• Permit to Work (PtW): Authorizes work on/near HV equipment after isolation, de-energization, and earthing.

• Sanction for Test (SfT): Authorizes testing on live or partially energized equipment (> 5000\,V test voltage).

• Limitation of Access (LoA): Allows limited access for non-electrical work in HV areas.

The DIESR Acronym

• Dead: Verified at zero voltage and disconnected.

• Isolate: Locked off from all supply points with Caution Notices fixed.

• Earth: Connected to Earth at all HV supply disconnection points.

• Screen: Barried/screened against adjacent live parts with Danger Notices.

• Release: Formally communicated to the working party via safety documents.

5 Safety Rules for Working Dead (HSG85)

1. Disconnect completely (Isolate all poles).

2. Secure against re-connection (Lock off and display warnings).

3. Verify installation is dead (Use an approved voltage detector).

4. Carry out earthing and short-circuiting.

5. Provide protection against adjacent live parts.

GIS and Converter Specific Operations

GIS Component Details

• Contains the Disconnecting Circuit Breaker ($Q01$) and Fast Earth Switch ($Q81$).

• $SF_6$ Monitoring: Gas densimeters monitor density. 1st Alarm indicates alarm pressure; 2nd Alarm indicates minimum service pressure.

• Interlocks: Prevent incorrect switching sequences. For example, $Q81$ is fitted with Key "T", which is only released when $Q81$ is closed. CB $Q01$ cannot be closed if the $Q81$ mode selector is not in Electrical mode.

• Voltage Detection System (VDS): Capdis S2 units used for monitoring bays $F01$ ($A301$), $F02$ ($A302$), and $F03$ ($A303$).

Converter and GBU Details

• Generator Disconnector Module (GDM): Motorized 3-phase disconnector connecting the generator to the converter. It has three positions: Closed, Open, and Ground.

• DC-Link Grounding Isolator: Used to short-circuit the DC-link for maintenance; blocked if voltage is > 50\,V.

• Grounding established by: Closing the circuit breaker with the three-position switch set to the ground position.

HMI and Remote Desktop Access Procedures

1. Set laptop IP to $10.10.11.99$ with Subnet $255.255.255.224$ (Alternative: $10.10.11.30$ and $255.255.255.0$).

2. Ping ABB IP $10.10.11.42$ via Command Prompt to verify communication.

3. Open Remote Desktop Connection (RDP) and enter IP $10.10.11.42$.

4. Credentials: Username: PCS-IPC\Customer; Password: Ywn^XDMi.

5. In the RDP, open the HMI folder and select "HMI start up".

6. Switching Logic: To establish grid-side grounding, insert keys "T" and "A" into lock $L1$, confirm the "Grid side voltage free" lamp is lit, and push the button to close both GRM/GRB disconnectors to earth.