Novel Voltage Source Converter for 10 kV Class Motor Drives

Narimani, Mehdi,Wu, Bin,Zargari, Navid Reza The Korean Institute of Power Electronics 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.5

This paper presents a novel seven-level (7L) voltage source converter for high-power medium-voltage applications. The proposed topology is an H-bridge connection of two nested neutral-point clamped (NNPC) converters and is referred to as an HNNPC converter. This converter exhibits advantageous features, such as operating over a wide range of output voltages, particularly for 10-15 kV applications, without the need to connect power semiconductors in series; high-quality output voltage; and fewer components relative to other classic seven-level topologies. A novel sinusoidal pulse width modulation technique is also developed for the proposed 7L-HNNPC converter to control flying capacitor voltages. One of the main features of the control strategy is the independent application of control to each arm of the converter to significantly reduce the complexity of the controller. The performance of the proposed converter is studied under different operating conditions via MATLAB/Simulink simulation, and its feasibility is evaluated experimentally on a scaled-down prototype converter.

Novel Voltage Source Converter for 10 kV Class Motor Drives

Mehdi Narimani,Bin Wu,Navid Reza Zargari 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.5

This paper presents a novel seven-level (7L) voltage source converter for high-power medium-voltage applications. The proposed topology is an H-bridge connection of two nested neutral-point clamped (NNPC) converters and is referred to as an HNNPC converter. This converter exhibits advantageous features, such as operating over a wide range of output voltages, particularly for 10–15 kV applications, without the need to connect power semiconductors in series; high-quality output voltage; and fewer components relative to other classic seven-level topologies. A novel sinusoidal pulse width modulation technique is also developed for the proposed 7L-HNNPC converter to control flying capacitor voltages. One of the main features of the control strategy is the independent application of control to each arm of the converter to significantly reduce the complexity of the controller. The performance of the proposed converter is studied under different operating conditions via MATLAB/Simulink simulation, and its feasibility is evaluated experimentally on a scaled-down prototype converter.

Using response surface methodology to optimize ultrasound-assisted oxidative desulfurization

Elhameh Narimani,Javad Alaei Kadijani,Hessameddin Alaei Kadijani 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.4

Latest strict environmental regulations have restricted the sulfur content of diesel fuels; therefore, deep desulfurization of fuels is required. Ultrasound-assisted oxidative desulfurization (UAOD) is an alternative for conventional desulfurization methods which can remove sulfur compounds from fuels under mild process conditions. In this study, UAOD of gasoil using tungstophosphoric acid catalyst and tetraoctylammonium bromide as a phase transfer agent in the presence of hydrogen peroxide as an oxidant was optimized. The optimal design of experiments was generated based on central composite face-centered design of Response surface methodology (RSM) to study effects of four process variables such as oxidant volume, mass of catalyst, mass of phase transfer agent and the ultrasonic wave amplitude on the sulfur conversion of gasoil. In addition, a predictive model of sulfur conversion was obtained based on RSM. The optimal values of process variables were evaluated to be 21.96 mL of oxidant, 1 gr of catalyst and 0.1 gr of phase transfer agent to achieve the maximum sulfur conversion of 95.92%.

Novel Voltage Source Converter for 10 ㎸ Class Motor Drives

Mehdi Narimani,Bin Wu,Navid Reza Zargari 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.5

This paper presents a novel seven-level (7L) voltage source converter for high-power medium-voltage applications. The proposed topology is an H-bridge connection of two nested neutral-point clamped (NNPC) converters and is referred to as an HNNPC converter. This converter exhibits advantageous features, such as operating over a wide range of output voltages, particularly for 10–15 ㎸ applications, without the need to connect power semiconductors in series; high-quality output voltage; and fewer components relative to other classic seven-level topologies. A novel sinusoidal pulse width modulation technique is also developed for the proposed 7L-HNNPC converter to control flying capacitor voltages. One of the main features of the control strategy is the independent application of control to each arm of the converter to significantly reduce the complexity of the controller. The performance of the proposed converter is studied under different operating conditions via MATLAB/Simulink simulation, and its feasibility is evaluated experimentally on a scaled-down prototype converter.

Power electronic converter reliability and prognosis review focusing on power switch module failures

Abuelnaga, Ahmed,Narimani, Mehdi,Bahman, Amir Sajjad The Korean Institute of Power Electronics 2021 JOURNAL OF POWER ELECTRONICS Vol.21 No.6

The current trend is to go for more electric systems that rely extensively on power electronics such as EVs/HEVs and electric aircrafts, along with an increased use of renewable energy resources and variable speed motor drives. However, some field failure reports have revealed that power electronic converters represent the weakest point in these systems. A significant percentage of system failures are due to power electronic converter failures, which compromises systems reliability. This raises questions regarding the validity of relying on the current power electronic converter technology to run mission-critical/must-to-be-safe systems. Although power electronic converter technology has reached an advanced level in terms of efficiency, power density, and control, extra work should be done when it comes to reliability. Reliability engineering brings performing failure data analysis, accelerated life testing, lifetime prediction, and the implementation of efficient maintenance and reliability improvement schemes into an integrated process. This process is meant to enhance the reliability of a product throughout its life cycle. This paper provides an overview of the application of the key aspects of new approaches in reliability engineering for power electronic converters. The focus of this paper is on power switch bond-wire modules since they are the most vulnerable component in power electronic converters. This paper also proposes two general schemes for condition-based remaining useful lifetime (RUL) that are discussed in detail.

Soft-Switching T-Type Multilevel Inverter

Chen, Tianyu,Narimani, Mehdi The Korean Institute of Power Electronics 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.5

In order to improve the conversion efficiency and mitigate the EMI problem of conventional hard-switching inverters, a new soft-switching DC-AC inverter with a compact structure and a low modulation complexity is proposed in this paper. In the proposed structure, resonant inductors are connected in series for the arm branches, and resonant capacitors are connected in parallel for the neutral point branches. With the help of resonant components, the proposed structure achieves zero-current switching on the arm branches and zero-voltage switching on the neutral point branches. When compared with state-of-art soft-switching topologies, the proposed topology does not need auxiliary switches. Moreover, the commutation algorithm to realize soft-switching can be easily implemented. In this paper, the principle of the resonant operation of the proposed soft-switching converter is presented and its performance is verified through simulation studies. The feasibility of the proposed inverter is evaluated experimentally with a 2.4-kW prototype.

A New ZVS-PWM Full-Bridge Boost Converter

Baei, Mohammadjavad,Narimani, Mehdi,Moschopoulos, Gerry The Korean Institute of Power Electronics 2014 JOURNAL OF POWER ELECTRONICS Vol.14 No.2

Pulse-width modulated (PWM) full-bridge boost converters are used in applications where the output voltage is considerably higher than the input voltage. Zero-voltage-switching (ZVS) is typically implemented in these converters. A new ZVS-PWM full-bridge converter is proposed in this paper. The proposed converter does not have any of the disadvantages associated with other converters of this type, including a complicated auxiliary circuit, increased current stresses in the main power switches, and load-dependent ZVS operation. The operation of the proposed converter, its steady-state characteristics, and its design are explained and examined. The feasibility of the converter is confirmed with results obtained from an experimental prototype.

A Multi-objective Fuzzy Adaptive PSO Algorithm for Location of Automatic Voltage Regulators in Radial Distribution Networks

Taher Niknam,Mohammad Rasoul Narimani,Rasoul Azizipanah-Abarghooee 제어·로봇·시스템학회 2012 International Journal of Control, Automation, and Vol.10 No.4

This paper proposes a multi-objective optimal location of Automatic Voltage Regulators (AVRs) in distribution systems at the presence of Distributed Generators (DGs) by a Fuzzy Adaptive Particle Swarm Optimization (FAPSO) algorithm. The proposed algorithm utilizes an external repository to save founded Pareto optimal solutions during the search process. The proposed technique allows the decision maker to select one of the Pareto optimal solutions (by trade-off) for different applications. The performance of the suggested algorithm on a 70-bus distribution network in comparison with other evolutionary methods such as Genetic algorithm and PSO is extraordinary.

A New ZVS-PWM Full-Bridge Boost Converter

Mohammadjavad Baei,Mehdi Narimani,Gerry Moschopoulos 전력전자학회 2014 JOURNAL OF POWER ELECTRONICS Vol.14 No.2

Pulse-width modulated (PWM) full-bridge boost converters are used in applications where the output voltage is considerably higher than the input voltage. Zero-voltage-switching (ZVS) is typically implemented in these converters. A new ZVS?PWM full-bridge converter is proposed in this paper. The proposed converter does not have any of the disadvantages associated with other converters of this type, including a complicated auxiliary circuit, increased current stresses in the main power switches, and load-dependent ZVS operation. The operation of the proposed converter, its steady-state characteristics, and its design are explained and examined. The feasibility of the converter is confirmed with results obtained from an experimental prototype.

Finite State Model-based Predictive Current Control with Two-step Horizon for Four-leg NPC Converters

Yaramasu, Venkata,Rivera, Marco,Narimani, Mehdi,Wu, Bin,Rodriguez, Jose The Korean Institute of Power Electronics 2014 JOURNAL OF POWER ELECTRONICS Vol.14 No.6

This study proposes a finite-state model predictive controller to regulate the load current and balance the DC-link capacitor voltages of a four-leg neutral-point-clamped converter. The discrete-time model of the converter, DC-link, inductive filter, and load is used to predict the future behavior of the load currents and the DC-link capacitor voltages for all possible switching states. The switching state that minimizes the cost function is selected and directly applied to the converter. The cost function is defined to minimize the error between the predicted load currents and their references, as well as to balance the DC-link capacitor voltages. Moreover, the current regulation performance is improved by using a two-step prediction horizon. The feasibility of the proposed predictive control scheme for different references and loads is verified through real-time implementation on the basis of dSPACEDS1103.