Electrotechnical Systems

130 Electrotechnical Systems

S1 and S3, the correcting signals are added to U

ref

. These signals are formed as the

outputs of the capacitor voltage proportional controllers with gains K

1

and K

2

multi-

plied by the output of the device, whose output signal is inversely proportional to the

load current, taking into account its sign (a small signal d is added in order to avoid

division by 0). When the load phase current is small, the controller is turned off by

the switch Sw.

The model4_9 is intended for study of the main system features. Each of three

subsystems—phases is realized according to the diagram in Figure 4.44. The inter-

mediate single-phase transformers with the diode rectiers are set in the subsystems

for the preliminary charge of the ...