A Quasi-Average Estimation Aided Hierarchical Control Scheme for Power Electronics-Based Islanded Microgrids

Abstract

Self-governed micro power networks are a promising solution for meeting the energy needs of isolated communities not having access to regular transmission networks. The control of such isolated networks requires regulation and “fair” sharing of several power generation and storage resources as well as efficient peer-to-peer coordination between power converters operating in the network. The regulation of key parameters as voltage, frequency and power sharing is to be ensured for the system to operate optimally. This paper proposes a new, de-centralized, and hierarchical control approach for power inverters in isolated micro networks with multi-layered controls, each addressing the regulation of key system parameters. The proposed scheme uses distributed quasi-averaging estimators at each participating node to achieve resilience towards disturbances caused by delayed transmission of measurement and control signals in the data acquisition and information exchange layer. Detailed system models are developed using MATLAB and Sim-power systems to test the effectiveness of the proposed scheme under varying control and network scenarios. The results of these studies are presented as pole zero evolutions, stability margins and case study wise simulations. The studies carried out verify the validity of the proposed control strategy for micro-distribution networks.

Finite‐time consensus for frequency and voltage restoration in microgird under communication interruptions

“…A continuous time model of the microgrid system is presented according to the above analysis. The active power droop parameters and the secondary control gains are changed to test the proposed distributed secondary control strategy model 35 . Figures 4A,B illustrate the effect of the variation of the active power droop coefficient m i on the stability of the system, where the range of m i varies from 5 × 10 −7 to 1 × 10 −1 .…”

“…However, the above two methods are less effective in dealing with complex nonlinear systems than neural networks by training historical data to infinitely fit any nonlinear system. What's more, distributed quasi‐averaging estimators was used in Reference 35 at each participating node to overcome the problems caused by communication delay. A fast algorithm was proposed in Reference 36 to detect and evaluate network connectivity based on the information stored at every node in the form of a look‐up table.…”

Peer-to-Peer Energy Trading in Micro/Mini-Grids for Local Energy Communities: A Review and Case Study of Nepal

“…A typical centralized control architecture is shown in Figure 2. MGCC constantly monitors the active and reactive power flow in the network and by comparing the market price of the electricity and other mains of sources, and taking into account the security concern of the system and the additional need of any of the nodes in the micro-grid, decides on the need for either importing the energy for consumption from an external distribution network, or exporting the produced energy for use in any other connected grids [30], [31]. In [32], authors show the functioning of a primary AC controller that communicates with two separate secondary DC microgrid controllers to stabilize the power in the AC multi-bus system.…”

Minimization of Network Induced Jitter Impact on FPGA-Based Control Systems for Power Electronics through Forward Error Correction

“…Traditional architecture for power converters and machine drives relies on a single inverter driving a three-phase electrical machine, as shown in Figure 1a. In segmented drives, conversely, In this scenario, the adoption of a communication method that is at the same time robust and has a low and predictable latency is of the utmost importance in order to support the required system dynamics [10]. Along with the latency, the jitter introduced in the system by the network layer is particularly problematic.…”