Description
ABB 3BHL000986P1006
1. Basic Information
ABB 3BHL000986P1006 is a high-power SCR rectifier power unit specially designed for generator excitation systems, compatible with ABB UNITROL series excitation control systems. It converts AC input voltage into adjustable DC excitation current to supply power for generator rotor windings, realizing generator terminal voltage stabilization and reactive power regulation.
Adopting a three-phase fully controlled bridge rectifier structure, the unit integrates high-power thyristors, trigger drive circuits and heat dissipation modules. It features strong overload capacity, fast response and stable output. It is widely used in thermal power, hydropower and cogeneration units for daily operation, maintenance and spare part replacement of excitation systems.
2. Core Technical Specifications
2.1 Power & Electrical Parameters
- Model: 3BHL000986P1006
- Type: Three-phase Fully Controlled SCR Rectifier Unit for Excitation System
- Compatible System: ABB UNITROL Series Excitation System
- Topology: Three-phase fully controlled bridge rectifier circuit
- Output Characteristic: Continuously adjustable DC excitation current
- Control Mode: Phase-shift triggering by excitation controller
- Overload Capacity: Supports field forcing overload for grid fault transient support
- Current Sharing: Built-in current sharing circuit for stable parallel operation
2.2 Device & Drive Parameters
- Core Device: Industrial high-power thyristor (SCR)
- Trigger Mode: Special stable pulse drive circuit with strong anti-interference
- Response Performance: Fast switching response following excitation command
- Heat Dissipation: High-efficiency air-cooling heat dissipation module
- Protection Circuit: RC snubber circuit for overvoltage suppression
2.3 Environmental & Physical Parameters
- Operating Temperature: 0℃～+55℃
- Storage Temperature: -40℃～+85℃
- Humidity Range: 5%～95%RH (Non-condensing)
- Vibration Resistance: Reinforced structure for long-term unit vibration scenarios
- Protection Grade: IP20
- Installation: Standard cabinet fixed installation
3. Main Features
- Precise Excitation Regulation: Adjusts DC excitation output accurately by controlling thyristor conduction angle, adapting to no-load, load, grid-connected and field-forcing working conditions.
- High Stability Output: Smooth output waveform with low ripple; RC absorption and current sharing design suppresses overvoltage and unbalanced current, improving operational reliability.
- Transient Overload Support: Standard field forcing capability provides transient excitation support during grid faults, meeting power system stability standards.
- Parallel Redundant Operation: Supports multi-module parallel expansion and redundant configuration to avoid system shutdown caused by single module failure.
- Strong Anti-interference Ability: Isolated trigger and power circuit prevents mis-triggering and signal loss caused by strong electromagnetic interference in power plants.
- Easy Maintenance & Replacement: Standard interface and size match UNITROL systems perfectly, no program or wiring modification required for replacement.
4. Working Principle
- AC Power Input: Three-phase AC voltage from the excitation transformer is input to the rectifier unit as the main power source.
- Trigger Pulse Reception: The excitation controller outputs phase-shift trigger pulses according to generator operating parameters.
- Controlled Rectification: The three-phase fully controlled bridge converts AC voltage into adjustable DC excitation voltage by controlling SCR conduction timing and angle.
- Current Sharing & Waveform Smoothing: Built-in current sharing and snubber circuits balance parallel current and suppress voltage spikes and waveform ripples.
- DC Excitation Output: Stable DC power is supplied to the generator rotor to establish magnetic field and realize voltage and reactive power regulation.
- Fault Protection Response: Withstands transient overcurrent and overvoltage; cooperates with system protection to avoid fault expansion and device damage.
5. Applications
5.1 Generator Excitation System Core Component
Serves as the key rectifying power unit for thermal power, hydropower and cogeneration units, ensuring normal power generation, grid connection and reactive power adjustment.
5.2 Old Excitation System Spare Replacement
Replaces aging, overheating and faulty rectifier units to restore excitation system performance and eliminate hidden dangers such as excitation fluctuation and loss of excitation shutdown.
5.3 Excitation System Maintenance & Expansion
Used for cabinet maintenance, power capacity expansion and redundant transformation to improve system load capacity and fault tolerance, meeting grid standard upgrading requirements.
5.4 Power Plant Electrical Technical Renovation
Updates outdated power hardware to improve excitation regulation accuracy and system stability, reducing unplanned unit shutdown risks.
