POWER SUPPLY

a. The EL 200 senses the generator voltage through transformer T2. This transtormer has tapsa

for use with the following input voltages: 90-139. 180-264. 342-528. and 540-660 Vac, +10%, 50/60

Hz.

b. A on Of the transformer (T2) outputfeeds the regulated power supply t0 produce · 14 Vdc

and a . 14 Vdc output for operating the circuitry 、 The transformer (T2) a 0 provides refer-

ence signals to the VAR detector, the watt detector and power the dc transducer (transformer T3).

b. The VAR and Watt Detectors convert the ac inputs tO dc outputs which represent ()y polarity

and amplitude) the VAR and Watt components Ofthe generator output current. The output of 1h9

VAR detector passes through a tapped resistor network (Curve Selector) to the VAR Comparator.

The VAR Comparator makes a comparison Of the Curve Selector output W1th a dc reference

vo 《 tage- If the leading VAR component (generator current) is higher than the reference voltage,

the Comparator outputs a signal through the voltage regulator/exciter that 刂 cause an exatation

limiting and thus, prevent operation outside the limit. This VAR limitlng action would normally

produce a limiting threshold (Refer to Figure 1 一 1 ) that would approach being a horizontal line at the

. 04 to . 0 . 6 per unit level. To produce the desired output culve ， a Watt signal IS passed through

the Forward Watt Amplifier (non-linear) 10 the VAR Comparator. TO assure proper operation ， a

calibration circuit is provlded 巧 set up the proper levels of operation for a wide range input

current levels.