1. Voltage and Stabilization Signals The Resulting Distributed Control
A New Distributed Controller for DC Microgrids Stability Enhancement
Voltage and Stabilization Signals
DC Test System
Why DC Microgrid?
Less number of conversion
No problem in voltage harmonics and reactive power
High quality of voltage for sensitive dc loads
DC BUS
DC/AC
DC/DC
DC/AC
AC/DC
DC/DC
AC BUS
Permanent Magnet Synchronous Generator
AC to DC converter
DC to DC converter,
A buck for the DC Resistive load
Community Microgrid of UWM
DC to DC converter,
A buck for the supercapacitor
Everything is modeled as a current source dependent on voltage (constant power).
Main grid is considered as voltage source without converter.
Simplification
Stability of DC Microgrids
Constant Power Loads (CPL) can endanger DC microgrid stability.
An example of CPL: Tightly regulated converters of electric drives
Traditional Lyapanov Equations controller
Our Proposed Controller
State Feedback Controller for The Simplified System
𝑋 =𝐴𝑋 𝑡 +𝐵𝑈 𝑡
The Resulting Distributed Control
The feedback system can guarantee microgrid stability only if the interaction between all elements are modeled
DC circuit breakers
Converter Controllers
Switching Effects
Literature Review
This shows the idea of distributed control. None of these controllers have access to other controller measurements.
Small Signal Stability
Active Damping
Virtual Impedance
Large Signal Stability
Central Controllers
Multi Agent Controllers
Controller Design
Less contribution from the loads
the least possible disturbance in all system signals
Objective Function
U(t) is designed to make the system stable and linear and provides the best solution for minimizing an objective function.
AC to DC interface controller
Total microgrid spate space linear equations
Optimization with the constraint of distributed control
State-space Average Model: Converter Modeling
The Resulting K
Solve the optimization for accurate model
Implement the controller in the community microgrid of UWM
Apply the concept to AC microgrids
Further work
This makes the whole system stable with the least extra power injection signals.
Supervisor: Rob Cuzner
Author: Marzieh Karami
Questions?