Homework 1

Problem Number

Answer and Comments

1

-60+j103.9

5

 50 ∠ 53.1  degrees

10

167-j12

13

12-j10

Homework 2

Problem Number

Answer and Comments

sglephhw.wp5

Z_T=16.144 ∠ 38.62 ohms

I_T =14.87 ∠ -38.62  A

V_ab = 161.61 ∠ -10.78 degrees V

Homework 3

Problem Number

Answer and Comments

spqhw.wp5

1.       P=2352.4 W Q=524 Vars

2.       Downward triangle with height Q=524, base P=2352.4  S=2410

3. Fp =0.9769 Leading

4. I_T =12.05 ∠ 12.55 degrees A

Homework 4

Problem Number

Answer and Comments

pfhw.wp5

a. Q_c=7634 Vars  C=11.6 uF

b. Q_c= 90,344 Var  C=137.5 uF

Homework 5

Problem Number

Answer and Comments

hw3phs1.wp5

a. V_p = 120.2 V

b. I_L=Ip=1.97 A

c. S_T=708.7 VA

d. F_p = 0.574 Leading

Homework 6

Problem Number

Answer and Comments

hw3phs3.wp5

a.  3984 V

b. 30 kVA

c. I_L = 2.51 A

hw3phs4.wp5

a) V_p = V_an = 2402 V

b)  I_L = 485.3 ∠ -81.9 degree A

c)  S_T = 3.49 MVA

d) S_p - 1.16 MVA

e) F_p = 0.141 Lag

Homework 7

Problem Number

Answer and Comments

hw3phs2.wp5

a) V_p =V_LN =V_L =13.2 kV

b) I_ab = 126.43 ∠ -16.7 A, I_bc = 126.43 ∠ -136.7 A I_ca = 126.43 ∠ 103.3   I_a = 218.98 ∠ -46.7 A,  I_b = 218.98 ∠-166.7 A,  I_c = 218.98 ∠ 73.3 A 

c) 5.007 MVA

d) 0.9578 lagging

pfcorr.wp5

a) P_T = 231.263 W, Q_T = 167392 VARs,

S_T=285487 VA

b)       Q_cT = 91379 VARs,  Q_cp =30,460 VARs,  V_p =480 V C=350 uF

c)        I_L = 292.8 A

Homework 8

Problem Number

Answer and Comments

wyedhw.wp5

a) V_ab = 480∠ 30  V_bc = 480∠-90 V_ca = 480∠150

b)  I_ab =  17.326∠70  I_bc =17.326∠50 

I_ca =17.326∠ 190

c)  I_a =  30∠100  I_b =30∠-20 I_c =30∠220

tqspd.wp5

a) 178 N-m

b) 98 N-m

c) 23.6 HP

Homework 9

Problem Number

Answer and Comments

Meterhw.wp5

Reading 10-1-97=8612 Reading 10-30-97=0254

1) 1642 kWh

2) PTR=120 CTR=160 Power Ratio=19,200

3) 31,526,4 MWh or 31,526,400 kWh

4) 41.47 kW

5) 796,262 kW

Homework 10

Problem Number

Answer and Comments

2-9/8

a) 6600 V

b)  45.83∠-46 A

c) 1375∠-46 A

d) 0.16 ∠-46 ohms

e) S = 302,478∠-46 VA   P= 210,119 W

Q = 217,584 VARs

Homework 11

Problem Number

Answer and Comments

2-11/8

a)  124.8∠ 0 V

b) 624 V

c)  3.12∠ -32 A

d) S = 1947∠ 32 VA   P= 1651 W Q = 1032 VARs

Homework 12

Problem Number

Answer and Comments

2-13/10

a) Z_eq = 8.97∠ 61.63 ohms

b) Z_eq = 0.56∠ 61.63 ohms

Homework 13

Problem Number

Answer and Comments

2-15/10

a) R_eq = 6.21 ohms  X_eq = 12.125j               

Z_eq = 13.623∠ 62.9 ohms

b) Z_in = 531∠ 41.95 ohms

c) I_p = 13.89∠-41.41 A

d) V_T= 7376.4∠0.53 V

e) I_oc = 0.427∠-75.5 A

f) Z_eq = 17280∠76 ohms

Homework 14

Problem Number

Answer and Comments

1

Z_pu=0.0043+0.0123j

2

Z_pu=0.0043+0.0123j  Impedance is the same on both sides of the transformer when rated power and voltages are used to find Z base

3

a) Z_actp=7.2+14.4j ohms

b) Z_acts=0.0018+0.036j ohms

4

a) I_base = 8.333 A  Z_base=14.4 ohms I_Cpu=0.69∠106.7

b) V_Lpu=0.958∠16.7

c) I_C=5.747∠106.7 A V_L=114.94∠16.7 V

5

Z_ppu=0.04995∠56.6 V_spu=1.0272∠1  V_s=246.53∠1 

Homework 15

Problem Number

Answer and Comments

2-23/12

a) 0.194 ohms

b) 0.012 ohms

2-25/12

a) I_sc = 45.45 pu  I_sc = 94,696 A

b) Z_pu = 0.0347,  Z%=3.472%

Homework 16

Problem Number

Answer and Comments

2-17

a) Z_eq = 0.0435∠83.5 ohms

b) E_LS = 495.28∠1.97 V

c) %VR=3.184%

Homework 17

Problem Number

Answer and Comments

2-39

a) R_feHS = 11,901 ohms X_mHS = 2962 ohms 

          R_eqLS = 1.743 ohms X_eqLS = 3.233 ohms

b) %VR = 2.511%

c) 97.37%

Homework 18

Problem Number

Answer and Comments

3phtxhw.wp5

1) Schematic diagram in notes

2) a=45.01

3) S=75 kVA

Homework 19

Problem Number

Answer and Comments

3-11

a) I_L = 416.7∠-43.95 A

b) I_A = 234.1∠-44.14 A    I_B = 182.6∠-43.71 A

Homework 20

Problem Number

Answer and Comments

3-1

a)  I_L= 225∠-10 A

b) I_HS =44.02∠-10 A  I_tr = 181∠-10 A 

I_LS = 225∠ -10  A

3-9

a=10.074

Homework 21

Problem Number

Answer and Comments

Ind-hw1.wp5

1800 rpm

4-4

a) s=0.01389

b) E_r = 1.444 V

c) f_r = 0.8334 Hz

Homework 22

Problem Number

Answer and Comments

4-6

a) 450 rpm

b) 16 poles

c)  3.6 Hz

Homework 23

Problem Number

Answer and Comments

4-10

a) 951 rpm

b) 20,250 W

c) 150 ft-lb

d) 147.7 ft-lb

e) 89.1

Homework 24

Problem Number

Answer and Comments

4-16

a) 90%

b) 1667 rpm

c) 110.3 ft-lb

d) 0.783 lagging

Homework 25

Problem Number

Answer and Comments

indhw1.wp5

a)  Z_in = 119.23 ∠25.8 ohms I₁ = 10.65∠-25.8 A 

I₂ = 9.51∠-5.77 A 

P = 33621 W

T_D = 201.1 ft-lb or 272.7 N-m

b) 92%

c) 0.90 lagging

Homework 26

Problem Number

Answer and Comments

5-22

       a) 93.93 A

b) 593< I_lr <668 A 

Homework 27

Problem Number

Answer and Comments

5-31

R₁ =0.1915 ohms
R₂ = 0.1895 ohms
x₁ = 0.5745 ohms
x₂ = 1.341 ohms 
X_m = 14.92 ohms
P_c+P_fw = 405 Watts

5-32

R₁ =0.200 ohms
R₂ = 0.25 ohms
x₁ = 1.2363 ohms
x₂ = 1.2363 ohms 
X_m = 41.02 ohms
P_c+P_fw = 259 Watts

Homework 28

Problem Number

Answer and Comments

5-35/18

                  P=186.9 kW,  Q=262.1 kVAR

Homework 29

Problem Number

Answer and Comments

8-1

150 rpm

8-2

30 Hz

8-3

80 poles

Homework 30

Problem Number

Answer and Comments

8-5

a) 5835 lb-ft

b) 161∠32.9 A

c) 29.17 degrees  E_f=13679∠-29.17 V

d) 12,412 lb-ft

Homework 31

Problem Number

Answer and Comments

8-7

a) -27.75 degrees  E_f=496∠-27.75 V

b) 1332.5 lb-ft

c) 666.3 lb-ft

Homework 32

Problem Number

Answer and Comments

8-17

a) -0.784 lagging

b) 0.896 lagging

Homework 33

Problem Number

Answer and Comments

9-1

1500 rpm

9-5

a) 499,858 W or 670 hp

b) 859.2 V

c) 580.9Ð-34.1 A

d) P=499,876 W Q=338,442 VARs

e) 0.828 lagging