electricityinthegrid

Understanding Electricity in the
 
Grid (Just a Little Bit Better) Highlights 
  • . . . The significance of the length of the wave is that over short distances (one mile is a very short distance for a 60 Hertz cycle) the magnitude of the voltage is virtually the same . . . 
  • . . . you have to repeat something 16 times to memory (by reading, doing, seeing, etc.) before it becomes a part of your permanent memory . . .
  • . . . In electricity, the 'y' values (the sine values) are simply used as multipliers . . .
  • . . . when knowledgable people talk about the grid, they talk about 3 phases . . .
  • . . . Figure 5.  AC 'Unit' Wave the Secondary Side of a Transformer Sees when Two Primary Wires (like in Fig. 4) are Connected in Series on a Transformer (a combined 'unit' sine curve (the multipliers) for a delta connection) . . .
  • . . . If that transformer has a delta connection, it is fed by two primary phase wires but the transformer connections on the secondary side (your connection to the energy) 'see' these two phases as basically one integrated phase . . . (See Fig. 4 and Fig. 5)
  • . . . Instead of the three-phase wiring typically found on the primary side of your 'home' transformer, you have two-phase wiring . . .
  • . . . The fact that the transformer was designed so the sine values add to zero will be significant later . . .
  • . . . Textbooks normally have lots of 'magic' numbers. . . . 1.732 . . . see this number on Figure 5 . . .
  • . . . With wye primaries and delta secondaries on transformers, if the loads on the transformers are not perfectly balanced, the floating bus on the primary side can have exceptionally high voltage and the current still needs to find 'a way back home.'  (the presence of the high voltage on the floating bus is a 'sign' that a power company has to produce extra power so the current can make the trip) . . .
  • . . . Mathematically (and in real life), the greatest power (power is defined as volts times amperes and measured in watts) is derived from the system when the peaks (amps and voltage) occur simultaneously.  Any deviation means a power company has to produce more power to get the same amount of energy to the consumers . . .
  • . . . The current must find its way home . . .
  • . . . Now power companies don't really want to 'see' the current come back.  If it does, they've had to produce a lot more energy to drive it home . . .
  • . . . When the current from multiple wires adds to zero after the electricity has gone through the loads and . . . is on the return trip in the circuit, the system is 'balanced' . . .
  • . . . for a perfectly balanced two- or three-phase system, if there's no measurable voltage (because the current waves cancel each other out), there shouldn't be any 'stray voltage'--a particular problem for farmers ...
  • . . . If you look closely at the concepts presented in this paper, you'll see built into them an array of opportunities for looking at how to increase the efficiencies in the electrical grid . . . It would be a shame if we did not take advantage of them . . .
     Copyright © 2005 by Lisa L. Osen