Involves a comprehensive process of planning, inspecting, and testing to ensure safety, reliability, and performance throughout the project lifecycle, from design to final commissioning. This includes verifying design documents, inspecting materials, checking civil and electrical works, and performing extensive electrical and control system testing to guarantee compliance with standards and correct operation. 

Quality assurance phases

1. Design and planning

• Design review: Critically review the entire control and protection (P&C) design package, which includes one-line diagrams, schematics, and wiring diagrams, to ensure accuracy and compliance with project specifications.
• Quality plan: Develop a project-specific quality plan that outlines objectives, standards, and procedures for all activities, including design, material procurement, and construction.
• Document control: Ensure all documentation is accurate, up-to-date, and accessible, and that all drawings are error-free to prevent future issues. 

2. Material and construction inspection

• Material verification: Inspect raw materials like concrete, steel, and cables, as well as major components like switchgear and transformers, to confirm they meet specifications.
• Site and civil work checks: Verify that site studies, soil investigation, and foundation work meet quality standards.
• Workmanship standards: Ensure that all construction activities, both civil and electrical, adhere to best practices and codes. 

3. Equipment and system testing and commissioning

• Visual and mechanical checks: Perform visual inspections of all equipment for signs of damage or wear. Check mechanical components and busbars for proper installation and integrity.
• Electrical testing: Conduct a series of tests on key equipment, such as:
• Transformer tests: Insulation resistance, power factor, and high-voltage withstand tests.
• Circuit breaker tests: Timing tests, contact resistance, and dielectric strength tests.
• Insulator and cable tests: High-voltage withstand tests to check for defects.
• Protection and control system testing:
• Verify the correct settings and functionality of protective relays.
• Perform primary injection tests to confirm correct operation of current and potential transformers and relays.
• Conduct high-voltage withstand tests and insulation resistance tests on all high-voltage equipment.
• Grounding system testing: Test the earth resistance and ensure proper continuity of the grounding system for personnel and equipment safety.
• Substation automation testing: Verify communication architecture, IED (Intelligent Electronic Device) configuration, and overall substation automation and control systems. 

4. Final inspection and documentation

• Final inspection: Address any issues found during the final inspection to create a "punch list" of non-conformities, which must be resolved before final handover.
• Performance testing: Conduct a final series of performance tests to confirm that all components function as a complete, integrated system.
• Documentation verification: Ensure all equipment manuals and maintenance records are current and accurate, and that all test results and reports are properly documented.