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This paper proposes solid rotor Interior Permanent Magnet (IPM) machine for an aircraft starter-generator. The key challenge in the design is to satisfy two operating conditions which are high starting torque and high speed continuous operation. A Surface mounted PM machine designed for such an application is used as a benchmark. Then, the IPM machine is designed adopting a solid rotor to have a maximum...
Induction motor drives supplied from diode front-end rectifiers are commonly used in industrial applications due to their low cost and reliability. However, the two-quadrant operation of such a topology makes the regenerative braking impossible. Braking resistors can be used to dissipate the braking power and provide enhanced braking capability, but additional hardware is then necessary. Alternatively,...
This paper investigates about the impact of the number of levels and of the corresponding modulations angles on the mitigation of harmonics in cascaded H-bridge multilevel inverters. A mathematical model to reduce Nth odd harmonics from the output voltage of a multilevel converter is represented as a constrained optimization problem. It is further transformed in an unconstrained optimization problem...
Mathematical model of laser heating with induction pre- and/or post-heating is presented and solved. The purpose of this combined way of heat treatment is to reduce residual mechanical stresses in the surface layers of the processed material produced by high temperature gradients at the spots heated by the laser beam. The 3D model takes into account all important nonlinearities including the temperature...
Flight tests of prototype UAV systems can be restricted by spatial constraints and they may bring risks of damage due to failures. Motivated by these, we presented a simulation approach based on Robot Operating System (ROS) and Gazebo. Unlike other state-of-the-art quadrotor simulators, we implemented the dynamics model of the UAV in ROS to achieve high fidelity behavior of the UAV. A hierarchical...
Chatter vibration is well known as an undesirable phenomenon, so various methods for chatter suppression have been proposed. Spindle speed variation as a triangular trajectory in the cutting process is one of the methods for chatter suppression. However, this method cannot suppress chatter vibration completely. Moreover, the triangular spindle speed variation requires large torque and a good response...
A novel kind of chip which is used in high precision and low cost arc detection circuit (leakage detection included) was designed. Based on CSMC's 0.5pm process, the pad is specially designed to produce a specific capacitor. Cascode current mirror and trimming capacitors are used to generate a precise timing signal. High speed, large bandwidth and low offset op-amps with rail to rail output stage...
Reliability of electric drives is of paramount importance for safety critical applications in transportation, medical and military industries. While numerous fault tolerant machine and inverter topologies have been developed for improving drive reliability, comprehensive reliability evaluation of fault tolerant electric drive systems has not been reported in literature. This paper performs quantitative...
In this study, we describe a novel method of fabricating shape-controlled calcium alginate gel microcapsules. Alginate-poly-L-lysine (PLL) hydrogel microcapsules with predefined shapes were constructed based on electrodeposition method. Firstly, electrolysis of water in alginate solutions with calcium carbonate particles induced alginate gelation on micro-patterned electrode to form 2D gel structures...
A novel multi-objective model predictive control strategy which is based on sorting and ranking approach for controlling converters of wind power system is proposed in this paper. In order to avoid the nontrivial process of weighting factors tuning that is typical in traditional multi-objective model predictive control, multi-objective optimization based on sorting is developed where quick sort is...
This paper proposes a controller design method using modeling-error feedback to improve steady-state performance for a system with time delay. The controller is designed based on the mixed H2/H∞ control assuring the stability condition with Lyapunov-Krasovskii functional. The proposed method resolves the problem of steady-state error due to model error which the conventional method using a communication...
This paper presents a new control scheme for a multi-terminal low frequency ac transmission system (LFAC) operating with a cycloconverter. The multi-terminal sytem uses two-phase LFAC system with a 12-pulse thyristor converter. A control scheme for power control by Virtual Synchronous Generator (VSG) among each terminal is explained in detail to understand the advantages of this method. Circuit configurations...
Bipedal robot has many advantages to locomotion in complex environments that wheeled robot cannot achieve. However, because of biped robot's complicated mechanism and the naturally unstable system, it is very susceptible to disturbance from the environment and humans in comparison with wheeled robots. Therefore, the prime task for biped robot walking is to maintain dynamic balance and recover from...
With regard to small DC brushless motors the problem of the cogging torques amplitude is considered. At the aim a special motor prototype, obtained by the substitution of the original ferrite magnets with bonded magnets prepared in the own laboratories, has been realized; such a prototype assumes the role of "reference motor" as regards some quantities introduced as "quality factors"...
We present a small, compact and portable envisaged lab-on-a-chip (LoC) device for point-of-care (PoC) detection of different key parameters on diabetes mellitus analysis; glucose, cholesterol, triglycerides and hematocrit. These four parameters, present in blood samples, are important in the standardized analysis affecting different patients with different medical conditions. The quantification of...
Laser Beam Melting (LBM) is a promising Additive Manufacturing technology that allows the layer-based production of complex metallic components suitable for industrial applications. Widespread application of LBM is hindered by a lack of quality management and process control. Elevated regions in produced layers pose a major risk to process stability as collisions between the powder coating mechanism...
In brushless dc machines the current commutation between phases is triggered based on information of the permanent-magnet flux position. In most BLDC drives, either sensors are used to detect this flux position or a self-sensing algorithm is applied to estimate the flux position instead. Over the last decades, different techniques have been developed to detect the current commutation instants from...
Understanding the operation of a building is key for improving it and reducing energy waste. However, today this is a mostly manual task for which domain experts use visual tools to analyze the large amounts of building data. We show how to automate this task by means of pattern extraction techniques. These allow human operators to simply consider well defined data patterns rather than vast amounts...
This paper deals with control of three-level neutral point clamped (NPC) voltage source converters (VSCs) for medium rating doubly fed induction generator (DFIG) based off-grid wind energy conversion system. A three-level three-leg insulated gate bipolar transistors (IGBTs) based NPC-VSC is used as a rotor converter (RC). Four-leg three-level IGBTs based NPC-VSC is used as a load converter (LC). A...
This paper presents an active queue management (AQM) architecture using a software-defined networking (SDN) controller. The SDN controller can achieve the AQM of a router from a remote location. It leads to realizing cooperative AQM of multiple routers and flexible AQM taking traffic conditions of the total network system into account. However, the AQM control system includes additional time-delay...
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