ABB XVC768116 3BHB007211R116 OLTC Voltage Regulating Control Board

ABB XVC768116 3BHB007211R116 Product Name: Excitation System Current Step Compensation Signal Board / OLTC Voltage Regulation Control Board

I. Basic Information
Brand: ABB
Module Model: XVC768116
Material Order Number: 3BHB007211R116
Compatible System: UNITROL 5000/6000 Generator Set Static Excitation System
Power Supply Specification: DC 24V
Installation Form: Embedded sub-board, plugged into the excitation main control board slot
Operating Temperature: -20℃ ~ +60℃, Industrial wide temperature design

Core Functions
OLTC On-load Voltage Regulation Current Smooth Compensation (IDC Step Compensation)
When switching the transformer on-load voltage regulation gears, it suppresses the drastic fluctuation of excitation current, smooths out reactive power impact, avoids grid voltage disturbance, and ensures the stability of the generator terminal voltage.
DC Ground Fault Detection
Through the built-in detection circuit, it realizes precise monitoring of the excitation DC circuit ground fault, and cooperates with the system to achieve grounding protection trip, alarm, preventing rotor insulation breakdown and damaging the unit.
Rectifier Bridge Unbalance Monitoring Protection
Real-time collection of multiple rectifier branch current signals, monitoring the three-phase current imbalance of the 12-pulse rectifier system, abnormal conditions of single bridge arm, triggering overcurrent and unbalance protection.
Power Factor / Reactive Power Auxiliary Regulation
Cooperating with the AVR main control to achieve closed-loop regulation of reactive power and power factor, supporting low-voltage ride-through function when the grid voltage drops, improving the unit’s grid stability operation capability.

Main Technical Parameters
Signal Acquisition Type: DC Current, Voltage Analog Quantity Signal
Fault Detection Accuracy: ±0.5% FS
Electrical Isolation: On-board photoelectric isolation, anti-strong electromagnetic interference in power plant
Communication Method: Parallel bus on the board for data interaction with the excitation main control unit
Protection Grade: IP20, embedded installation in the cabinet

Typical Application Scenarios
ABB UNITROL series excitation system for thermal power, hydropower, and gas power stations. It is often used in conjunction with UFC760BE145 and UFC762AE101, mainly for generating units with main transformer on-load voltage regulation, solving the reactive power impact problem during gear shifting, and also undertaking the task of excitation power circuit fault monitoring and protection.