0195136047.pdf

810 BASIC CONTROL SYSTEMS

Minicomputer

Generator

Outputvariables

Codedcommand

D/A

converter

Steamturbine

Valve

D/A

converter

Electrohydraulic

transducer

Digital

multiplexer

Digital

transducers

Digital output

Digital output

(Voltage control)

(Speed control)

Analog

transducers

Analog

multiplexer

A/D

converter

Sample-and-hold

(data aquisition)

From steamboiler

Exciter

Figure 16.3.5

Computer control of a turbogenerator unit.