| Abstract |
The HYGEN load-adaptive variable-speed generating system produces standard AC 50Hz, 230 Vrms
voltage for common applications – and for very sensitive loads. The system comprises two energy
sources. The primary energy source is an engine-driven alternator and the secondary source is a battery
bank. The permanent magnet generator generates an output of variable voltage and variable frequency,
which is converted by an AC/DC/AC power electronic converter system, resulting in a high quality
output voltage, even under the most adverse load conditions. Energy flow between the engine, battery
and load is controlled by means of the converters. The control feature of the DC/DC converter, which is
connected to the output of the generator through a rectifier and LC filter, permits manipulation of th
torque acting on the engine by controlling the current in the alternator. In addition, the voltage of th
alternator is allowed to vary freely. Mathematical models of all subsystems are described, and ar
finally integrated into a complex model of the whole system. Models of subsystems and also the overall
model are implemented in Simulink. In order to simplify the calculations, all electrical AC units ar
converted to the equivalent DC–link model using the DC/DC converter model with average quantities.
The dynamic behaviour of the system under several step-loads at different operating points is analysed
and discussed. Resistive step-loads are applied to the output of the inverter because they represent th
most difficult load conditions, i.e. inrush current di/dt approaching infinity. Computer simulation
results are presented. |
