A DC short-shunt compound generator has the following specifications: \R_\a = 0.05\\Omega, \R_\sf = 0.3\\Omega, \R_\shf = 200\\Omega and voltage drop per brush is 1 V. Find the generated EMF when the generator deliver a load of 30 A at 220 V.

SSE JE Electrical Engineering 29 Oct 2020 Shift 2 Papers

Question : 129 of 200

Marks: +1, -0

A DC short-shunt compound generator has the following specifications:

\R_\a = 0.05\Ω

\R_\sf = 0.3\Ω

\R_\shf = 200\Ω

and voltage drop per brush is 1 V. Find the generated EMF when the generator deliver a load of 30 A at 220 V.

Solution:

\V _{ \t }=220 \V

\I _{1}=30 \A

\R _{ \sf }=0.3 \Ω

\R _{ \a }=0.05 \Ω

\R _{ \shf }=200 \Ω

\V _{ \b }=1 V

\V _{ \a }= \V _{ \t }+ \I _{ \l } \R _{ \sf }

\V _{ \a }=220+30 ×0.3

\V _{ \a }=229 \V

\I _{ \sh }={ \V _{ \a }}/{ \R _{ \sh }}={229}/{200}=1.145 \A

\I _{ \a }= \I _{ \sh }+ \I _{1}

\I _{ \a }=1.145+30=31.145 \A

\E _{ \g }= \V _{ \a }+ \I _{ \a } \R _{ \a }+2 \V _{ \b }

\E _{ \g }=229+31.145 × 0.05+2 ×1

\E _{ \g }=232.55725 \V

∴ Generated EMF = 232.55725 V

Go to Question:

Prev Question

Next Question