A novel excitation control scheme for exciting-magnetic doubly salient brushless DC generator

A doubly salient brushless high voltage DC power system, that is composed of a 12/8 pole exciting-magnetic doubly salient (EMDS) generator and a diode bridge rectifier, was developed. The generator performance, including no-load characteristic, voltage regulating characteristic and efficiency, are tested and analyzed in a 30 kW prototype generator. The test results show that the proposed 12/8 pole EMDS generator offers the advantage of high efficiency over wide power range, A automatic voltage regulator based on nonlinear PI combined with bang-bang control was proposed and designed. The digital voltage regulator was implemented based on DSP (TMS320F240). The experiments on a 30 kW EMDS generator were carried. In order to improve further the dynamic characteristic, the nonlinear PI algorithm with load-current forward compensating (LCFC) control was developed, the proposed nonlinear PI with LCFC method has been compared with nonlinear PI. The experimental results verify that the proposed new controller not only offers faster dynamic response, but also reduces voltage surge during loading and unloading transient process. A good transient process and steady state characteristics are achieved over wider load current range.