New Decentralized Control of Mesh AC Microgrids: Study, Stability, and Robustness Analysis

In this paper, we investigated the power sharing issues in mesh islanded microgrids that contain several distributed generators (DGs) and loads connected to different points of common coupling (PCC). Firstly, an improved decentralized droop control algorithm is proposed to achieve the active and reactive power sharing of different DGs in reconfigurable mesh islanded microgrids. Accurate power sharing was obtained even though line parameters or the mesh microgrid configuration were unknown. Secondly a state-space model of the whole mesh microgrid was developed, considering several generators with their decentralized controllers, line feeders, and dynamic loads. This model was used to design parameters of droop controllers, to study the asymptotic stability and the robustness properties of the system. All strategies and analyses were validated by simulation based on the generic microgrid detailed in the standard IEEE 9bus test feeder.

FPGA Realization of the Reconfigurable Mesh Counting Algorithm

Pass transistor logic (PTL) is a circuit design technique wherein transistors are used as switches. The reconfigurable mesh (RM) is a model that exploits the power of PTLs signal switching, by enabling flexible bus connections in a grid of processing elements containing switches. RM algorithms have theoretical results proving that [Formula: see text] can speed up computations significantly. However, the RM assumes that the latency of broadcasting a signal through [Formula: see text] switches (bus length) is 1. This is an unrealistic assumption preventing physical realizations of the RM. We propose the restricted-RM (RRM) wherein the bus lengths are restricted to [Formula: see text], [Formula: see text]. We show that counting the number of 1-bits in an input of [Formula: see text] bits can be done in [Formula: see text] steps for [Formula: see text] by an [Formula: see text] RRM. An almost matching lower bound is presented, using a technique which adds to the few existing lower-bound techniques in this area. Finally, the algorithm was directly coded over an FPGA, outperforming an optimal tree of adders. This work presents an alternative way of counting, which is fundamental for summing, beating regular Boolean circuits for large numbers, where summing a vast amount of numbers is the basis of any accelerator in embedded systems such as neural-nets and streaming. a

Adaptive Booth Algorithm for Three-integers Multiplication for Reconfigurable Mesh

This paper presents a three-integers multiplication algorithm R = A * X * Y for Reconfigurable Mesh (RM). It is based on a three-integer multiplication algorithm for faster FPGA implementations. We show that multiplying three integers of n bits can be performed on a 3D RM of size (3n + log⁡ n + 1) × (2n+1 +3) × n+1 using 44 + 18 · log log MNO steps, where MNO is a bound which is related to the number of sequences of ‘1’s in the multiplied numbers. The value of MNO is bounded by n but experimentally we show that on the average it is n. Two algorithms for solving multiplication on a RM exists and their techniques are asymptotically better time wise, O(1) and O(log⁡* n), but they suffer from large hidden constants and slow data insertion time (O(n)) respectively. The proposed algorithm is relatively simple and faster on the average (via sampling input values) then the previous two algorithms thus contributes in making the RM a practical and feasible model. Our experiments show a significant improvement in the expected number of elementary operations for the proposed algorithm.