Flexible System Integration and Advanced Hierarchical Control Architectures in the Microgrid Research Laboratory of Aalborg University

Abstract

--This paper presents the system integration and hierarchical control implementation in an inverter-based microgrid research laboratory (MGRL) in Aalborg University, Denmark. MGRL aims to provide a flexible experimental platform for comprehensive studies of microgrids. The structure of the laboratory, including the facilities, configurations and communication network, is first introduced. The complete control system is based on a generic hierarchical control scheme including primary, secondary and tertiary control. Primary control loops are developed and implemented in digital control platform, while system supervision, advanced secondary and tertiary management are realized in a microgrid central controller. The software and hardware schemes are described. Several example case studies are introduced and performed in order to achieve power quality regulation, energy management and flywheel energy storage system control. Experimental results are presented to show the performance of the whole system.

Sizing Study of Second Life Li-ion Batteries for Enhancing Renewable Energy Grid Integration

“…The first part of the process of assessing the required rating of the SLBESS is to determine the control algorithm that controls the battery for providing the variability smoothing service [27]- [29].…”

Black Start Strategy for PV-ESS Multi-Microgrids with Three-Phase/Single-Phase Architecture

“…The values of P set1 and P set2 should be set up reasonably to realize the hysteresis control of multi-microsources coordination and avoid the frequent movement of the control system: ∆P " P dpt´Pnet (8) where P dpt is the set-point tie-line active power controlled by MGCC; P net is the real-time tie-line active power. The flowchart of the grid-connected algorithm of grid-connected state is shown Figure 4: Energies 2016, 9, 372 8 of 14 SOC, the lower limited SOC, and the upper limited SOC of the lth PQ adjustable ESS respectively; Ppql, Ppqlmaxdisc, Ppqlmaxch and Ppqlset are the real-time output active power, the maximum discharge power, the maximum charge power, and the set-point power of the lth PQ adjustable ESS respectively; SOCvf, and SOCvfmin are the real-time SOC and the lower limited SOC of the main power supply respectively; Pvfmaxdisc, Pvfmaxch, Pvf and Pvfset are the maximum discharge power, the maximum charge power, the realtime power, and the set-point power of the main power supply respectively; Ploadn is the power of the nth load; KpqPVm is the switch state of the mth PQ adjustable PV; KPVm is the switch state of the mth PV system.…”

“…Unlike the single MG, multi-microgrids (MMGs) are a hybrid systems made up of multiple sub-microgrids (SMGs), to meet specific function and control targets [6][7][8]. Considering the independent operation of the SMG and the coordinated operation of the whole system, the control scheme of MMGs should not only ensure the stable operation of each SMG, but also the power exchange between SMGs.…”

Containment and Consensus-Based Distributed Coordination Control to Achieve Bounded Voltage and Precise Reactive Power Sharing in Islanded AC Microgrids

“…Based on the MG concept, hierarchical control architecture, which was commonly applied in power systems, has been adopted and modified to coordinate different control objectives and to standardize the MG operation [2], [3]. Typically, the primary level deals with the voltage/current regulation and power sharing local control.…”