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High number of magnetic poles in an electric machine allows reduction in radial thickness of stator and rotor yoke and thus heavy alloy. If frequency is allowed to increase with pole-count (constant speed), power level can be maintained. Thus, high frequency, together with high pole count, can improve power density of rotating electric machines. The proposed high frequency concept is applied to designing...
An ongoing challenge in power system research is how to best utilize time-varying power system data and ultimately how to present it to human operators and planners in a concise and understandable way. This paper presents two newer visualization techniques for time-varying data across wide-area networks, including (1) animation loops that combine periodic snapshots of the grid into time lapse videos...
To insure reliability in electrical networks, loads are supplied by more than one source. In this paper a transfer scheme using two Static Transfer Switches (STS) located remotely is presented for transferring the feeder load to an alternate source that is out of phase from the primary (preferred source). The objective is to have a minimum disruption to the feeder voltage in terms of the dead time...
This work focuses on the analysis of the transient voltage stability at the point of interconnection (POI) of offshore wind farms following faults on the collector system. In particular, this study studies offshore wind farms that use an AC export system to transfer generated power onshore and investigates transient voltage stability under the influence of operating reactive power support equipment...
To address the environmental concerns throughout the world, many new power sources, such as renewable energy, are being introduced. In order to maintain the reliability and stability of the system while integrating these inputs, many systems have started integrating battery energy storage systems. However, the introduction of such system has been very slow due to its high capital costs. Therefore,...
This paper proposes a new Z-source inverter architecture that does not require filtering at the output side to generate smooth ac voltages. Also, it provides a control strategy based on the concept of Model Predictive Control (MPC) for the proposed inverter. Since each switch of the proposed inverter makes a specific impact on the output of the inverter, MPC is a proper method to control the proposed...
Diverse grid structures in HVDC systems are generally possible. Though HVDC fault detection methods from overcurrent to derivative detection have recently been proposed, a broad discussion about reasonable fault localization is mostly absent. A MATLAB Simulink model with four different transmission line scenarios was developed for application-oriented considerations of short circuit fault detection...
In this paper, Compressed Air Energy Storage (CAES) as a popular technology for wind energy storage, is mathematically integrated with a hydraulic wind power system. Hydraulic machinery as prime-movers is utilized to gain the benefit of eliminating costly and heavy gearboxes. The goal of this work is to improve the power delivery performance while maintaining a stable frequency generation in a 600kW...
This paper presents design of Electronic Differential System (EDS) for an Electric Vehicle (EV) with in-wheel motor. EDS is generally used in EVs due to some drawbacks of mechanical differential such as being heavy systems and mechanical losses caused by the powertrains. According to the turning angle of the wheel, task of EDS for front wheels is to adjust rpm of the wheels. On the contrary for rear...
One of the problems pertaining to model predictive control (MPC) of a motor drive system is choosing the weighting factors in the cost function. The prevalent approach to obtain the weighting factors is an empirical method. The weighting factors chosen by this method are always fixed and designed based on a single operating point. Therefore, the designed weighting factors are not suitable for the...
Demand response (DR) is a key component of smart grids that can bring a lot of benefits to power system operators and customers. Most literature on DR focuses on the operation, control and planning aspects of “smart grids”, while its impact on, and potential for improving system reliability is less studied. DR can mitigate the operational limit violations by changing the load profile when the reliability...
This paper address the issues of surplus power that would happen when the sum of the generated power of Photovoltaic(PV) Generation Systems and minimal output of utility power plant exceeds total electricity demand that would affect the stable operation of power system. The cooperative control of customer's appliances such as Heat Pump Water Heater(HPWH) and battery is applied for utilizing surplus...
Wind and Solar power are the most promising and rapidly developing renewable energy technologies that exist in our world today. They are also termed variable energy resources since their natural resources, wind speed and solar irradiance, are intermittent in nature. This variability is a critical factor when estimating the annual energy of wind and solar sources. Capital and operational costs associated...
The paper presents a speed estimation method for the induction motor (IM) drive. The speed is obtained using the Model Reference Adaptive System (MRAS) principle and is based on a second order sliding mode (SM) observer. First, the stationary frame fluxes of the IM are obtained using a Voltage Model Observer - this is based on the stator equations (which do not depend on speed) and serves as the reference...
In this paper a new Modulated Model Predictive Control (MPC) method has been proposed to overcome the stability problems caused by a constant power load (CPL) in cascaded converter system. The proposed method calculates the duty cycle of the converter switches based on the predicted value of the converter output voltage when two different switching configurations are chosen to be applied to the converter...
Phasor Measurement Unit (PMU) is considered to be the most significant device in future power system measurements. It provides phasor information (both magnitude and phase angle) which can be used in the real time control of power systems. In this paper, optimal PMU placement problem (OPP) is articulated as a binary integer linear programming (BILP) using Balas additive algorithm (BAA). PMU installations...
Common mode (CM) Electromagnetic interference (EMI) noise in an isolated converter is mainly due to parasitic capacitance occurring within the SMPS (Switch-mode Power Supply). It flows through transformer coupling capacitance and the parasitic capacitance of MOSFETs and diodes. Several techniques have been proposed in the literature to mitigate the common mode noise flowing through transformer windings...
This paper presents an enhanced phase-locked loop (PLL) based on the second-order generalized integrator (SOGI) for tracking and restructuring alternating current (AC) signals with unknown amplitude, DC offsets, frequency, phase angle and phase sequence. According to the second-order generalized integrator configured as a quadrature signal generator (SOGI-QSG), amplitudes, DC offsets and the phase...
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