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Systems are being developed for power distribution on future navy ships to effectively incorporate advanced electrical systems requiring DC power. These islanded DC microgrids provide new challenges to the management of power flow throughout the system, and thus require advanced controls to accurately regulate and stabilise the systems during changing operational conditions. Therefore, adaptive droop control is proposed as a power management layer for these maritime DC microgrids. This paper reports on a method that uses adaptation of the controller parameters to account for uncertainty and changes in the system in order to accurately regulate the power sharing among distributed generation sources and to stabilise the bus voltage of the system. The proposed method is applied to a virtual prototype of a medium voltage direct current (MVDC) ship power system and demonstrated through notional operational scenarios to test the effectiveness of the control algorithm utilising controller hardware in the loop (CHIL) experimentation. [ABSTRACT FROM AUTHOR]

Development of a precise dynamic model is a critical step in design and analysis of optimal control strategies for switched-reluctance machines (SRM). This paper is focused on important issues concerning the development of such models and their subsequent use in designing control strategies for SRM drives. The main goal in modeling is to provide a good accuracy over the entire speed and torque range. To achieve this objective, the following requirements need to be met: 1) a good accuracy in matching the inductance of each stator phase; 2) inclusion of mutual effects when significant overlap among phases exists; 3) inclusion of short flux-path operation in each electrical cycle when significant overlap among adjacent phases exists; and 4) capability for autocalibration to cope with parameter variations incurred by manufacturing imperfections and operational conditions. In this paper, in addition to an in-depth discussion of the above factors, a practical modeling approach along with an autocalibration strategy is presented. A simple test collects the necessary data in developing the proposed model. Inherent separation among mechanical, electrical, and control time constants has been used to develop the autocalibration process. Experimental results are presented to validate the proposed method. Index Terms--Long flux path, mutual inductance, self-inductance, short flux path, switched reluctance machines (SRMs).

Switched reluctance machines (SRM) offer attractive attributes for automotive applications. These include robustness to harsh operational conditions, rugged structure, fault resilient performance, and a wide range of speed. The main debate over the adequacy of switched reluctance drives in automotive applications has often focused on efficiency and position sensorless control over the entire speed range, adaptation of control algorithms in the presence of parameter variations, and high levels of acoustic noise and vibration. The present paper demonstrates three key technologies developed over the past few years that have resulted in tangible improvements in the performance of SRM/generators (SRM/G) as related to the above areas of interest. This paper intends to illustrate the new possibilities and remaining challenges in applications of SRM in automotive industry. The proposed technologies have been validated by simulation and experimental results. Index Terms--Acoustic noice, switched reluctance machines (SRM), vibration.

Development of a reliable, smooth, and precise position sensorless startup routine is an integral part of the switched reluctance machine (SRM) control. The proposed sensorless startup method presented in this paper presents high grade performance and does not require additional hardware or memory. Further, the proposed sensorless technique is extended to rotating shaft conditions. These capabilities are highly demanded by automotive applications such as starter/alternator and electric power steering systems. An assessment of the impact of motor parameters and diagnostic signal measurement on the quality of the sensorless startup method is also included. This will help practicing engineers to make judicious selections for implementation of the proposed technique. Experimental and theoretical results are included to validate our claims. Index Terms--Diagnostic signal measurement, switched reluctance machine (SRM).

This paper presents the results of an investigation of components of the electromagnetic force in the air gap of an 8/6 switched reluctance machine (SRM). Using a Maxwell stress method, variations of radial and tangential force components due to saliency of the machine and saturation have been studied. Access to distribution of the force components acting on the rotor and stator enables us to provide a more accurate picture of the torque generation and vibration in this family of electric machines. Furthermore, distribution of magnetic forces under multiphase excitation has been studied in detail. Our findings show that bipolar excitation of SRM phases, resulting in a short flux path magnetic circuit, favors its efficiency and power quality while generating higher torque with less pulsation. This is a significant improvement, particularly for automotive applications where the difference in the required number of power electronics components can be justified. An experimental 2-kW 42-V 8/6 SRM drive which has been designed and manufactured in our energy system laboratory was targeted for this study. In addition to our extensive finite-element analysis, experimental results have been provided to prove theoretical claims. Index Terms--Bipolar, normal force, switched reluctance machine (SRM), tangential force.

Current vehicle architectures utilize belt driven components such as the coolant pump, air-conditioner, power steering pump, etc. However, the trend toward more electric vehicles requires electromechanical energy conversion devices to replace these inefficient mechanical components. It is essential that electrical machines used in automotive applications to be compatible with the corresponding mechanical and electrical terminals. Furthermore, replacement of belt driven components with electrical drives should be performed as efficient and cost effective as possible. Bipolar switched reluctance machines (SRM) are both cost effective and very robust to the effects of temperature variation. They also offer a very wide speed range and an excellent mechanical integrity, which optimally suits a range of automotive applications including electric propulsion. This paper presents a detailed investigation of the performance indices for bipolar SRM drives. Using a Maxwell stress method, variations of radial and tangential force components due to saliency of the machine and saturation have been studied. Access to distribution of the force components acting on the rotor and stator enables us to provide a more accurate picture of the torque generation and vibration in this family of electric machines. Furthermore, distribution of magnetic forces under multiphase excitation has been studied in detail. Our findings show that bipolar excitation of SRM phases, resulting in a short flux path magnetic circuit, favors its efficiency and power quality while generating higher torque with less pulsation. This is a significant improvement, particularly for automotive applications where the difference in the required number of power electronics components can be justified. An experimental, 2-kW, 42-V, 8/6 SRM drive which has been designed and manufactured in our energy system laboratory was targeted for this study. In addition to our extensive finite-element (FE) analysis, experimental results have been provided to prove theoretical claims. Index Terms--Bipolar, normal force, switched reluctance machines (SRM), tangential force.

Electric systems for naval applications create a challenge for the power system associated control. When incorporating loads with a high-power ramp rate within what is essentially an islanded microgrid, energy sources that supplement generators must be used due to the ramp rate constraints of the generators; this is where energy storages play a key role. A higher-level control layer is needed to effectively coordinate the distributed energy storage in order to ensure that the effect on the generators is minimised. The Energy Management layer is responsible for maintaining the desired state of charge for the distributed energy storage and ensuring that load demand is met while minimising ramp rate violations. In this paper, a distributed Energy Management scheme for a 4-zone ship power system is presented. Experimental results validate the proposed control technique using hardware controllers interfacing with a real-time simulator. [ABSTRACT FROM AUTHOR]