Control and Design of Microgrid Components - Power Systems ...

List of Figures
Figure 1.1 Microgrid Architecture Diagram.................................................................................. 5
Figure 2.1 Current Direction as the Switch is Closed.................................................................... 8
Figure 2.2 Power vs. Frequency Droop. ........................................................................................ 9
Figure 2.3 Island Connection of Two Microsources, A has Higher Frequency than B................. 9
Figure 2.4 Island Connection of Two Microsources, A has Lower Frequency than B. .............. 10
Figure 2.5 Receding Trajectory of Voltage Vector V.................................................................. 11
Figure 2.6 Voltages on Either Side and Across the Static Switch............................................... 12
Figure 2.7 Three Phase Currents of the Static Switch, with Condition (ii) not Met.................... 13
Figure 2.8 Switch Voltage and Microsource Current, with Condition (ii) not Met..................... 14
Figure 2.9 Microsource Power Injection and Frequency, with Condition (ii) not Met. .............. 14
Figure 2.10 Voltage Vector Plane Showing Correct Reclose Timing......................................... 15
Figure 2.11 Three Phase Currents of the Static Switch, with Condition (ii) Met........................ 16
Figure 2.12 Switch Voltage and Microsource Current, with Condition (ii) Met......................... 16
Figure 2.13 Microsource Power Injection and Frequency, with Condition (ii) Met. .................. 17
Figure 2.14 Voltage Across the Static Switch During Synchronization, 1sec/div, 200V/div. .... 18
Figure 2.15 Grid and Microsource Current During Synchronization, 100ms/div, 10A/div........ 18
Figure 3.1 Microsource Diagram................................................................................................. 19
Figure 3.2 Final Version of Microsource Control. ...................................................................... 20
Figure 3.3 P and Q Calculation Blocks........................................................................................ 21
Figure 3.4 Voltage Magnitude Calculation Block. ...................................................................... 22
Figure 3.5 Selective Filter Diagram............................................................................................. 23
Figure 3.6 Selective Filter Response. .......................................................................................... 23
Figure 3.7 Voltage Control Block................................................................................................ 24
Figure 3.8 Q versus Load Voltage, E, Droop Block.................................................................... 25
Figure 3.9 Q versus Load Voltage, E, Droop Characteristic. ...................................................... 26
Figure 3.10 Power – Frequency Droop Characteristic................................................................. 27
Figure 3.11 Block Diagram of the Active Power Droop. ............................................................ 27
Figure 3.12 Microsource Elements: Prime Mover, Storage, Inverter.......................................... 28
Figure 3.13 Diagram of a Unit Regulating Output Active Power. .............................................. 30
Figure 3.14 Unit Power Configuration. ....................................................................................... 31
Figure 3.15 Steady State P-ω Characteristics with Fixed, Minimum Slope................................ 32
Figure 3.16 Effectively Limiting Pmax on Output Power Control.............................................. 33
Figure 3.17 Effectively Limiting Pmin=0 on Output Power Control. ......................................... 35
Figure 3.18 Offset Generation to Limit Max Power with Integral Block.................................... 36
Figure 3.19 Offset Generation to Limit Minimum Power with Integral Block........................... 37
Figure 3.20 Control Diagram to Enforce Limits with Unit Power Control................................. 38
Figure 3.21 Diagram of a Unit Regulating Feeder Power Flow.................................................. 39
Figure 3.22 Load Tracking Configuration................................................................................... 40
Figure 3.23 Steady State Characteristics on the F-ω Droop with Feeder Flow Control.............. 41
Figure 3.24 Single (a), and Multiple (b) Feeders Source Connectivity....................................... 42
Figure 3.25 Sliding Window of Unit Power Limits..................................................................... 43
Figure 3.26 Steady State Characteristics for (a) P=0 Limit and (b) P=Pmax Limit. ................... 45
Figure 3.27 Steady State Characteristic Including Limits on the F-ω Plane with Feeder Flow
Control. ................................................................................................................................. 45
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