Basler DECS-100-B15 Digital Automatic Voltage Regulator – Precision Excitation Control

The Basler DECS-100-B15 is a cutting-edge digital AVR that delivers outstanding voltage regulation for synchronous generators of any size. Its 32-bit microcontroller architecture enables fast and accurate control of the field current, maintaining terminal voltage within ±0.25% of the setpoint under all steady-state and transient conditions. The B15 power stage provides 15 A continuous field current with 30 A forcing for 10 seconds, handling even the most demanding load steps.

Advanced Control Algorithms

The regulator employs a dual-loop control strategy: an inner current loop for rapid field response and an outer voltage loop for precise regulation. Adaptive gain adjustments automatically compensate for generator impedance changes, ensuring optimal damping without manual tuning. An integrated power system stabilizer (PSS) adds a damping signal to mitigate low-frequency oscillations, critical for weak-grid connections.

Protection and Limiting

Comprehensive protection includes over-excitation limit (OEL), under-excitation limit (UEL), voltage-dependent reactive current limit, and stator current limit. The under-frequency roll-off function reduces the voltage setpoint when frequency drops, protecting the generator from over-excitation at low speeds. All limits are programmable with inverse-time or definite-time characteristics.

Communication and Monitoring

Standard Modbus RTU (RS-485) allows integration with SCADA systems. Optional Ethernet, Profibus, or DNP3 modules are available. The front-panel LCD displays real-time phasors, metering, and event logs. The relay also supports waveform capture for fault analysis.

Installation and Configuration

Designed for 19-inch rack or panel mounting, with a wide auxiliary supply (24–250 VDC or 100–240 VAC). Configuration is via the front keypad or BESTCOMS software, which also allows custom logic programming.

Applications

Widely used in power plants, industrial cogeneration, marine propulsion, and emergency standby systems, where high reliability and grid code compliance are essential.

Maintenance

Solid-state design ensures minimal maintenance. Self-diagnostics and fault logging facilitate troubleshooting.

Compliance

Meets IEEE 421.5, IEC 60068, and UL 508 standards.

Conclusion

The DECS-100-B15 offers a powerful, flexible, and robust solution for generator excitation, meeting the needs of modern power systems.