Description

ABB Unitrol 1000-7 Digital Static Excitation Control System

Technical Specifications

• Product Model: Unitrol 1000-7
• Brand: ABB
• Warranty: One Year
• Input Voltage: 24 VDC auxiliary control power; 100–240 V AC/DC main power stage supply, PT/CT derived machine measuring signals
• Operating Temperature: -25°C to +70°C continuous rated operation
• Storage Temperature: -40°C to +85°C
• Response Time: ≤20ms full voltage correction response for 95% step voltage deviation
• Protection Class: IP20 when installed inside locked power plant control cabinet
• Accuracy Class: Voltage regulation accuracy ≤±0.5% full scale under steady-state load
• Output Frequency: Grid synchronous 50/60Hz thyristor rectifier output, DC excitation field power
• Rated Current Range: Maximum 6000A DC field excitation output, rated field voltage up to 500V DC
• Communication Interface: Dual redundant Ethernet ports, RS485 serial bus, USB local debugging port, internal CAN bus
• Supported Protocols: Modbus TCP/RTU, DNP3, IEC 60870-5-103/104, IEC 61850, ABB proprietary internal bus protocol
• Overload Capacity: Overexcitation/underexcitation limiters, V/Hz protection, crowbar overvoltage suppression, short-circuit locking, reverse polarity and ESD surge protection
• Dimensions: 442mm (W) × 132mm (H) × 300mm (D) standard 19-inch rack chassis footprint
• 

Product Overview

The ABB Unitrol 1000-7 is a fully digital dual-redundant static excitation system designed for large-capacity synchronous generators and synchronous motors, serving as the core voltage regulation and grid stability control unit for power generation assets. It precisely adjusts the DC excitation current supplied to the generator rotor winding in real time, stabilizing terminal voltage, controlling reactive power output, and damping low-frequency power oscillation on the connected power grid.

This excitation system addresses critical stability challenges of large-scale power generation units. Its dual hot-standby redundant controller architecture eliminates single-point control failure, complying with strict power plant functional safety requirements. Embedded Power System Stabilizer (PSS) complies with IEEE Std 421.5 standards to suppress inter-area grid oscillations, while integrated Fault Ride Through (FRT) logic maintains generator grid connection during voltage sags and swells to meet modern grid code mandates. Comprehensive multi-loop limiters prevent rotor overheating, stator overload and V/Hz overflux damage under abnormal operating conditions. The factory-calibrated platform supports air-cooled or water-cooled thyristor power bridges, with full event logging and waveform recording for post-fault root cause analysis.