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Career · 2017

Risk Optimized Microgrid Resource Management

Explore the four cases ↓

Research explorer · saved GAMS results

A network of decisions.

What changes when the edge of the grid starts making its own dispatch decisions? Follow four stages of participation through the same 33-bus network.

IEEE 33-bus distribution feeder

Final saved schedule · hour 17
123456789101112131415161718192021222324252627282930313233SUBSTATION33 BUSES / 12.66 kV123456789101112131415161718192021222324252627282930313233SUBSTATION
→ Real-power direction━ Near line limit$0 → $0.20 / kWh
Line 30 · buses 30–31
500 kW

Toward the substation · 100% of line limit

Bus 31 voltage
0.992 p.u.

1.000 is nominal voltage

Local dispatch price
0.095 $/kWh

Price received by this local controller

Even this baseline has congestion. At the evening peak, the outer branches carry power back toward the feeder. Read the case ↗

Two parts of the feedback loop

Bus 31, across the day.

The local controller receives a price and returns a schedule. The master then solves the network again and produces new nodal prices. These are different signals, at different steps of the same round.

$/kWh0.200.10011224
━ Local price received━ Resulting nodal price

Hour 17 · the resulting nodal price at bus 31 is $0.095/kWh.

How the model works

Coordinate the network. Keep device decisions local.

Local controllers

Each controller schedules its own devices against the prices it receives: dispatchable generation, flexible load, battery and EV constraints. The master sees net demand or injection, rather than every device behind the meter.

Published results, model boundaries and source

The transition is between levels of distributed participation, not an electrical transient. The study uses day-ahead schedules and an iterative optimization loop; it is not a time-domain stability simulation.

Case inputs also change the master controller’s resource fleet to retain feasibility and congestion. These four cases are not a controlled sweep with every other variable held constant.

Table 3.2 · reported objective values, in per-unit terms
ParticipationMC, riskLC, riskMC, no riskLC, no risk
0%0.02790.02760.02800.0276
33%0.02080.03390.02080.0268
66%0.02410.03840.02390.0263
100%0.02130.04350.02110.0258

Risk adjustment keeps the master-controller results close to the runs without risk, while changing local-controller costs. At 100% participation, termination at the iteration limit must not be confused with convergence.

The interactive figures replay the archived risk-adjusted GAMS runs at their saved precision. Lines show final real-power flow; node voltage comes from the linearized network solution. The local-price trace is the price received at the start of the final round; the nodal-price trace is the master’s resulting price. Arrows encode direction; motion is illustrative, not electricity’s propagation speed. No optimizer runs in your browser.

The original model also includes reactive power, device energy and operating constraints, and CVaR-based reliability adjustments. Its linearized power-flow approximation and stopping behavior limit what can be concluded from these runs.

Read the full thesis (PDF, 5.2 MB) ↗ · University of Denver record ↗

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