Equivalent Circuit Model of a DC Machine

Question 1

what do we have now that we produced torque from the dc machine

Answer 1

mechanical power

Question 2

formula for mechanical power (form shee)

Answer 2

pmech = F X R x omega = Na(BfIaL)romega

angular velocity of omega
circumferential velo of v= r*omega

Question 3

what does this formula simplyfiy to (form shee)

Answer 3

Pmech = Iae = Tomega

Question 4

how is some energy lost in the system

Answer 4

due to armature resistance RA

Question 5

what is the forumala for Pin(elec) and V(in) formu sheet

Answer 5

Pin(elec) = P(mech) + Ia^2 * Ra
2nd part comes from P=i^2*R formula

-> Ia^2 * Ra + Ia*e -> Ia(IaRa +e) = V(in)Ia

implying that dc input voltage is Vin = IaRa +e

Question 6

what is P(out(mech))

Answer 6

Pout = P(mech) - P(mech(loss))

Question 7

what does power in at full load mean

Answer 7

P(in(elec) therefore 100% effeiciency

Question 8

how to tfind percntage efficiency

Answer 8

P(mech)/P(in(elec)) x 100

Question 9

what does Ra represent

Answer 9

amrature R - the ohmic loss in the armature circuit

Question 10

what can induced emf formula be written as (form sheet)

Answer 10

e = NaBFL*V = Ke * omega

where 𝑘𝐸 = 𝑁𝐴𝐵𝐹𝑙r (machine constant) and the emf induced is called back emf