The MicroGrid Manager is an off-grid inverter, a bidirectional converter that charges and discharges batteries
from or to the Electrical Grid. It also allows the transition from island mode (off-grid) to a connected mode (grid-tied)
and vice versa.
When in Connected Mode, the converter follows active and reactive setpoints allowing the energy balance.
In Island Mode, the converter fixes the grid requirements: voltage and frequency.
The control could perform additional functions, as:
- Microgrid management: management of solar and wind converters, demand management, ...
- Anti-islanding algorithm: allowing the transition from Connected to Island and vice versa
Each cabinet integrates VSC modules and DSP control boards equipped with all necessary power components, electrical
protections, auxiliary electronics and security elements.
The power electronics is based on a back to back topology formed by 2 voltage source converters.
It is a multifunctional converter that allows a wide range of applications.
Active and reactive power control
The converter can control the injection or consumption of active and reactive power to the grid in all modes.
Some applications and features:
The converter is composed by an Active Rectifier, a DC bus stage, and 3 independent IGBT half-bridge branches with
output filters and sensors. Each DC output channel can be regulated independently or they can be parallelized for high
current applications. The following operating modes are included in the standard version and can be selected by the user:
- Decentralized Storage System to Increase Self-Consumption
- Reduce Investment in Power System Infrastructure
- Flatten the Demand and the Load Curves
- Control Capability for QoS: THDv and Freq
- Emergency Power Supply
- Grid-to-Island and Island-to-Grid Management
- Extended Life Batteries
- Managing of second life batteries
"Increasing the Hosting Capacity of Distributed Energy Resources Using Storage and Communication",
Nicholas Etherden, Doctoral Thesis, Luleň University of Technology, 2014.
"Converter induced resonances in microgrids due to high harmonic distortion"
N. Etherden, J.M. Fernandez et al. ICREPQ'14 Cˇrdoba.