Active vs Reactive Power Level 200 | Wind Energy Fact — Transcript

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1. 0:03[Music]
2. 0:06my name is chelsea ben
3. 0:07i'm here to talk to you today about
4. 0:08active versus reactive power
5. 0:11so we build wind turbines here at one
6. 0:13energy one of the things that we do a
7. 0:15lot of
8. 0:16is education and one of the questions we
9. 0:18get
10. 0:19quite frequently is what is active power
11. 0:22what is reactive power and what is
12. 0:24apparent power and why does it matter so
13. 0:26these are terms that are widely used in
14. 0:28the industry
15. 0:29these are things that you look at when
16. 0:32you are an energy manager for
17. 0:34a company when you're looking to
18. 0:36understand your billing
19. 0:38as a residential customer as a corporate
20. 0:40customer as a cni
21. 0:41customer any of those things so active
22. 0:45reactive and apparent power are three
23. 0:48types of power that are very very
24. 0:49confusing unless you break it down
25. 0:51so that's going to be the goal of today
26. 0:54so active power is defined as the real
27. 0:56power
28. 0:57actually dissipated in a system reactive
29. 1:00power
30. 1:01on the flip side is phantom power which
31. 1:03flows forward and backward without doing
32. 1:05any useful work in the system
33. 1:07so bringing that down to earth a little
34. 1:10bit
35. 1:12let's take a look at this purely
36. 1:14resistive load
37. 1:16so a purely resistive load you're going
38. 1:19to see that i've put
39. 1:20voltage here in green current and pink
40. 1:24i should have started this video with a
41. 1:25disclaimer that my handwriting is
42. 1:27abysmal
43. 1:28and my english teachers were never
44. 1:30pleased but
45. 1:32as you can see they peak at the same
46. 1:35time voltage and current peak at the
47. 1:36same time
48. 1:37they go to zero at the same time
49. 1:41and so what what that means is that
50. 1:44voltage and current are in phase with
51. 1:46one another and a purely resistive
52. 1:48load so now what if
53. 1:51we're looking at power now what happens
54. 1:54when you look at power
55. 1:56so you're going to take your your
56. 1:59current
57. 2:00and multiply it by your voltage to get
58. 2:03power
59. 2:04so what that's going to look like
60. 2:11you're gonna have positive
61. 2:15power you know
62. 2:18as in a purely resistive load and so
63. 2:22this type of representation we call
64. 2:27active power
65. 2:31now let's take a look at the flip side
66. 2:34so now on the flip side let's look at a
67. 2:36purely reactive load
68. 2:38so again you've got voltage and current
69. 2:41they're a little out of phase from one
70. 2:43another
71. 2:44and what you're going to notice is if we
72. 2:47look at that same
73. 2:48current versus multiplied by voltage
74. 2:51uh it's going to be positive positive
75. 2:55times a positive
76. 2:56stays positive right so it's going to be
77. 2:58something like
78. 3:01this is where that goes negative when a
79. 3:04negative goes negative
80. 3:07becomes positive and you've got this
81. 3:17something like that and so you're going
82. 3:20to notice
83. 3:21that a purely reactive load has both
84. 3:24positive
85. 3:26and negative power
86. 3:29and it goes back and forth and so
87. 3:34looking at this a little bit just to
88. 3:36reiterate active power
89. 3:37does not change direction and remains
90. 3:40positive
91. 3:40whereas reactive power changes direction
92. 3:44and is positive and negative meaning
93. 3:46that it goes both from source to load
94. 3:48and load to source so examples
95. 3:51of some reactive loads that you're going
96. 3:53to see active power is
97. 3:56a lot easier to visualize a lot easier
98. 3:57to think about
99. 3:59but reactive power is not
100. 4:02so when we talk about reactive power
101. 4:04we're talking about things like
102. 4:05inductors and capacitors
103. 4:07that dissipate zero power but drop
104. 4:10voltage
105. 4:11and draw current giving the impression
106. 4:13that they do dissipate power
107. 4:15and so when we're talking about these
108. 4:17things reactive power
109. 4:18motors capacitors inductors those are
110. 4:21all common examples of things that draw
111. 4:23reactive power so we kind of
112. 4:27showed this on that first board that we
113. 4:29were looking at
114. 4:30this is what we call the power triangle
115. 4:33and this is where we talked about those
116. 4:35three types of power
117. 4:36and so reactive power or q
118. 4:40measured in var active power
119. 4:43or p measured in watts and a
120. 4:47apparent power measured in va
121. 4:50also known as s and then the angle
122. 4:53between
123. 4:54active power and apparent power is also
124. 4:57is called theta
125. 4:59in this instance but as impedance is the
126. 5:01impedance
127. 5:02phase angle sometimes you see that as z
128. 5:08so you can use trigonometry
129. 5:13and you can kind of solve for one
130. 5:14another these are some formulas we're
131. 5:16not going to go through them this is
132. 5:19above and beyond what we want to do
133. 5:21today but just to reiterate active power
134. 5:24produces electricity
135. 5:26heat light mechanical energy and
136. 5:28reactive power produces an ac magnetic
137. 5:31field
138. 5:31and so active power apparent power and
139. 5:34reactive power
140. 5:35are only applicable in ac settings they
141. 5:38are not applicable at all in a dc
142. 5:40setting cool so moving on
143. 5:44so putting all this together some final
144. 5:47notes here
145. 5:48active power is a function of
146. 5:50dissipative elements
147. 5:51usually resistance reactive power is a
148. 5:54function
149. 5:55of circuits reactants both
150. 5:58active and reactive power are burdens to
151. 6:01transmission lines
152. 6:02that's pretty key here and that's going
153. 6:05to be one of the big takeaways
154. 6:07so to put all this together what really
155. 6:10matters
156. 6:11is the ratio of active power to apparent
157. 6:13power
158. 6:14or the ratio of reactive power to
159. 6:16apparent power
160. 6:18the ratio of active power to apparent
161. 6:20power is called your power factor
162. 6:23so this matters a lot when you're
163. 6:25talking about utility billing
164. 6:26and so a utility is going to look at
165. 6:30let's say a plant's overall power factor
166. 6:33and they're going to say okay both
167. 6:36active power
168. 6:36and reactive power are burdens to the
169. 6:39transmission line
170. 6:40so they're going to build differently as
171. 6:42if this were 0.8
172. 6:430.7 they're going to build very
173. 6:46differently if it's 0.4
174. 6:48it all depends on what's in the fine
175. 6:51print of your utility bills
176. 6:53so at one energy we build on-site wind
177. 6:56projects that interconnect physically
178. 6:58to a customer's site what that means is
179. 7:01we're changing
180. 7:02we're trying to change that load profile
181. 7:04at the plant
182. 7:06so customers will still receive a bill
183. 7:08from their primary electric utility
184. 7:11so we oftentimes
185. 7:15meter but every project we've put in the
186. 7:17ground thus far has not been
187. 7:19a 100 producer for a plant or a facility
188. 7:23so they have to be supplemented in some
189. 7:25way
190. 7:26when we talk about supplementing their
191. 7:28utility bill we're talking
192. 7:30about supplementing them with you know a
193. 7:32local utility
194. 7:33transmission distribution something
195. 7:35along those lines
196. 7:37so like i mentioned utilities billing is
197. 7:39based on
198. 7:40power factor so the customer has a
199. 7:43reactive power load that is high
200. 7:46motors inductors anything that that
201. 7:49changes the sh
202. 7:49that that phasing between current and
203. 7:52voltage
204. 7:53there's a waste or burden to the
205. 7:55electric supplier because of that
206. 7:56reactive power so
207. 8:00putting this all together understanding
208. 8:03power factor
209. 8:04is a key for an energy manager at any at
210. 8:07any
211. 8:07major consumer so to understand their
212. 8:10load and billing from the utility
213. 8:12you need to understand power factor to
214. 8:14understand power factor
215. 8:15you need to understand active and
216. 8:16reactive power and how it works
217. 8:19so hopefully this was a little bit
218. 8:21helpful this is a very very very brief
219. 8:24tornado of an intro to it there are
220. 8:26years of data years of studies
221. 8:29people's dissertations written on this
222. 8:31particular subject so
223. 8:33have at it if you're interested thank
224. 8:36[Music]
225. 8:38you
226. 8:39[Music]
227. 8:46you