The three phases from low-voltage (LV) and high-voltage (HV) generators are combined within generator neutral cells to create a neutral point, which is grounded through a resistor.

Unlike standard neutral grounding resistors, the generator neutral cell combines the three generator phases to establish the neutral point. The primary objectives of this application are:

• Sending data to the relay via phase current transformers installed on the three phases before the neutral point.
• Limiting ground fault current to levels that prevent damage to the generator, ensuring maximum operational continuity and safety.
• Detecting faults via the current transformer connected to the neutral point of the generator neutral cell and identifying fault durations through relays.
• Limiting transient oscillatory and non-oscillatory voltage fluctuations caused by fault current interruption, thereby protecting system equipment insulation levels.
• Maintaining safe step voltage levels in the field to enhance personnel safety.
• Preventing overheating and mechanical stress on all equipment exposed to fault currents.

Technical Specifications:

• Compatibility: Suitable for generator sets up to 17.5 kV
• Current Capacity: Applicable for currents up to 5000 A
• Resistor Material: Corrosion-resistant stainless steel, designed for harsh field conditions
• Design Features: Special mechanical and electrical design to withstand high temperatures and sudden surges
• Components: Phase current transformers, neutral current, and voltage transformers

Resistor Element:

• Fault current-resistant designs, including helical winding, edge winding, or grid resistors
• Modular, braided, stainless-steel bolt-connected structure ensuring uninterrupted electrical continuity at high temperatures
• Series and/or parallel connections with braided, overlapping terminals, featuring high cross-section and low contact resistance for excellent conductivity under high currents

Cabinet:

• Designed for indoor use with excellent cooling and standard IP3X protection
• Robust, modular cell design with frame-mounted resistance blocks
• Hinged door with patented design for maximum operational safety
• Corrosion-resistant lifting lugs and fasteners
• Fully enclosed design made from 2 mm thick sheet steel
• Stainless steel product and warning labels
• Type-tested manufacturing compliant with IEC 62271-200 standards

Options:

• Custom-painted cells in requested color codes
• Auxiliary equipment, such as voltage transformers, surge arresters, panel heaters, and analog indicators
• Special designs for high-altitude operations

Tropicalized manufacturing options for corrosion resistance in tropical conditions

Advantage

• High personal and equipment safety by using fully type tested SME enclosure as per IEC 62271-200
• Easy access and maintenance
• High insulation and mechanical resistance
• Special production option against corrosion for tropical environment conditions
• Proven reliability with unique design
• Additional equipment can be included (surge arrester, panel heater, etc)

Application Area

• Thermal Power Plants
• Nuclear Power Plants
• Gas Power Plants
• Hydroelectric Power Plants
• Biomass Energy Plants
• Wind Energy Plants