Basler DECS-200

The DECS-200 is a microprocessor-based digital excitation control system (AVR) from Basler Electric for synchronous generators and brushless exciters. This DECS-200 integrates PWM power stage, voltage regulation, excitation limiting and generator protection in one compact unit, with regulation accuracy up to 0.25%. It supports 32VDC, 63VDC and 125VDC excitation output variants, maximum 15A DC field current.

This DECS-200 provides four main control modes: automatic voltage regulation, manual field current control, VAR control and power factor control. It supports bumpless transfer between active and standby regulators, widely used for redundant excitation rack configuration. Built-in limiters include V/Hz limiter, minimum excitation limit, maximum excitation limit and underfrequency compensation. It also features exciter diode monitoring (EDM), seven generator protection functions, sequence of event recording and oscillography for fault analysis.

This DECS-200 is equipped with backlit LCD and local keypad for on-site setup and data viewing. Communication ports include front RS-232 for BESTCOMS software commissioning, side RS-232 for redundant regulator interconnection, and RS-485 supporting Modbus RTU for SCADA and DCS connection. Remote setpoint can be adjusted via 4-20mA, ±10VDC or contact inputs. It operates reliably from -40°C to +60°C cabinet environment.

The DECS-200 is widely applied on diesel generators, gas turbines, steam turbines and hydro units in power plants, oil & gas and industrial self-generation stations. The DECS-200 series has been discontinued by Basler, the successor model is DECS-250. Most available DECS-200 units are tested surplus spare parts for excitation cabinet overhaul and emergency replacement of legacy generator control systems.