ABB UNITROL® 5000 System Configuration

ABB UNITROL® 5000 System Configuration
The UNITROL 5000 is designed as a modular “building-block system”. More than 80 % of all systems can be made from type-tested system components. This guarantees higher quality and makes shorter delivery times possible. The power section consists of one or more thyristor power converters, field breaker on the AC or DC side, the field flashing circuit and the solid state de-excitation system with Crowbar.

High availability due to the additional backup current regulator To further increase the availability of the excitation system, in addition to the voltage regulator (AUTO) and the excitation current regulator (MAN), an independent current regulator (separate device with power supply, measurement and gate control circuits) can be used. Because of the follow-up control for all the inactive regulators, in the case of failure of the active regulator a smooth switch-over to a ready-to-operate regulator channel is guaran teed.

Less wiring thanks to the internal ARCnet® field bus The exchange of data within the system, e.g. between the voltage regulator, power components and interface devices takes place via the serial ARCnet bus. Additional interfaces or control panels can be located and operated up to a distance of several 1000 m via an optical link.
Powerful and reliable power converters Either compact power converters of the DCS 500 series or type UNL 13300 or Verithyr power converters are used for the UNITROL 5000. The type and the number of parallel power converters are based on the required field current, the ceiling voltage and the maximum duty cycle required by the customer. The following options are available: • Natural or forced cooling • Redundant fans • Possibility to do maintenance work on one power converter during the operation of the system (with 5-pole isolator).
Equal distribution of the current between several power converters For the first time for parallel power con verters, a new ABB development offers regulated distribution of the total cur rent between the active units. This can prevent the overloading of individual thyristor branches due to unsymmetrical current flows and significantly reduces the probability of a failure of the individual power converters (see Fig. 3 on page 5).