Coordinated Wide-Area Regulation of Transmission System for Voltage Profile Improvement and Power Loss Reduction

Asadzadeh, Babak,Golshannavaz, Sajjad The Korean Institute of Electrical and Electronic 2017 Transactions on Electrical and Electronic Material Vol.18 No.5

In this paper, an optimal approach for the wide-area regulation of control devices in a transmission network is proposed. In order to realize an improved voltage profile and reduced power loss, existing devices such as tap-changing transformers, synchronous machines, and capacitor banks should be controlled in a coordinated and on-line manner. It is well-understood that phasor measurement units in transmission substations allow the system operators to access the on-line loading and operation status of the network. Accordingly, this study proposes efficient software applications that can be employed in area operation centers. Thus, the implanted control devices can be regulated in an on-line and wide-area coordinated approach. In this process, efficient objective functions are devised for both voltage profile improvement and power loss reduction. Subsequently, sensitivity analysis is carried out to determine the best weighting factors for these objectives. Extensive numerical studies are conducted on an IEEE 14-bus test system and a real-world system named the Azarbayjan Regional Transmission Network. The obtained results are discussed in detail to highlight the promising improvements.

Design of an Asymmetrical Three-phase Inverter for Load Balancing and Power Factor Correction Based on Power Analysis

Mokhtari, M.,Golshannavaz, S.,Nazarpour, D.,Aminifar, F. The Korean Institute of Electrical Engineers 2011 Journal of Electrical Engineering & Technology Vol.6 No.3

This paper presents a novel theoretical method based on power analysis to obtain voltage reference values for an inverter-based compensator. This type of compensator, which is installed in parallel with the load, is usually referred to as the active filter. The proposed method is tailored to design the compensator in such a way that it can simultaneously balance the asymmetric load, as well as correct the power factor of the supply side. For clarity, a static compensator is first considered and a recursive algorithm is utilized to calculate the reactance values. The algorithm is then extended to calculate voltage reference values when the compensator is inverter based. It is evident that the compensator would be asymmetric since the load is unbalanced. The salient feature associated with the proposed method is that the circuit representation of system load is not required and that the load is recognized just by its active and reactive consumptions. Hence, the type and connection of load do not matter. The validity and performance of the new approach are analyzed via a numerical example, and the obtained results are thoroughly discussed.

Design of an Asymmetrical Three-phase Inverter for Load Balancing and Power Factor Correction Based on Power Analysis

M. Mokhtari,S. Golshannavaz,D. Nazarpour,F. Aminifar 대한전기학회 2011 Journal of Electrical Engineering & Technology Vol.6 No.3

This paper presents a novel theoretical method based on power analysis to obtain voltage reference values for an inverter-based compensator. This type of compensator, which is installed in parallel with the load, is usually referred to as the active filter. The proposed method is tailored to design the compensator in such a way that it can simultaneously balance the asymmetric load, as well as correct the power factor of the supply side. For clarity, a static compensator is first considered and a recursive algorithm is utilized to calculate the reactance values. The algorithm is then extended to calculate voltage reference values when the compensator is inverter based. It is evident that the compensator would be asymmetric since the load is unbalanced. The salient feature associated with the proposed method is that the circuit representation of system load is not required and that the load is recognized just by its active and reactive consumptions. Hence, the type and connection of load do not matter. The validity and performance of the new approach are analyzed via a numerical example, and the obtained results are thoroughly discussed.

Coordinated Wide-Area Regulation of Transmission System for Voltage Profile Improvement and Power Loss Reduction

Babak Asadzadeh,Sajjad Golshannavaz 한국전기전자재료학회 2017 Transactions on Electrical and Electronic Material Vol.18 No.5

In this paper, an optimal approach for the wide-area regulation of control devices in a transmission network is proposed. In order to realize an improved voltage profile and reduced power loss, existing devices such as tap-changing transformers, synchronous machines, and capacitor banks should be controlled in a coordinated and on-line manner. It is well-understood that phasor measurement units in transmission substations allow the system operators to access the on-line loading and operation status of the network. Accordingly, this study proposes efficient software applications that can be employed in area operation centers. Thus, the implanted control devices can be regulated in an on-line and wide-area coordinated approach. In this process, efficient objective functions are devised for both voltage profile improvement and power loss reduction. Subsequently, sensitivity analysis is carried out to determine the best weighting factors for these objectives. Extensive numerical studies are conducted on an IEEE 14-bus test system and a real-world system named the Azarbayjan Regional Transmission Network. The obtained results are discussed in detail to highlight the promising improvements.

An Optimal Procedure for Sizing and Siting of DGs and Smart Meters in Active Distribution Networks Considering Loss Reduction

Sattarpour, T.,Nazarpour, D.,Golshannavaz, S.,Siano, P. The Korean Institute of Electrical Engineers 2015 Journal of Electrical Engineering & Technology Vol.10 No.3

The presence of responsive loads in the promising active distribution networks (ADNs) would definitely affect the power system problems such as distributed generations (DGs) studies. Hence, an optimal procedure is proposed herein which takes into account the simultaneous placement of DGs and smart meters (SMs) in ADNs. SMs are taken into consideration for the sake of successful implementing of demand response programs (DRPs) such as direct load control (DLC) with end-side consumers. Seeking to power loss minimization, the optimization procedure is tackled with genetic algorithm (GA) and tested thoroughly on 69-bus distribution test system. Different scenarios including variations in the number of DG units, adaptive power factor (APF) mode for DGs to support reactive power, and individual or simultaneous placing of DGs and SMs have been established and interrogated in depth. The obtained results certify the considerable effect of DRPs and APF mode in determining the optimal size and site of DGs to be connected in ADN resulting to the lowest value of power losses as well.

A New Design for Cascaded Multilevel Inverters with Reduced Part Counts

Choupan, Reza,Nazarpour, Daryoush,Golshannavaz, Sajjad The Korean Institute of Electrical and Electronic 2017 Transactions on Electrical and Electronic Material Vol.18 No.4

This paper deals with the design and implementation of an efficient topology for cascaded multilevel inverters with reduced part counts. In the proposed design, a well-established basic unit is first developed. The series extension of this unit results in the formation of the proposed multilevel inverter. The proposed design minimizes the number of power electronic components including insulated-gate bipolar transistors and gate driver circuits, which in turn cuts down the size of the inverter assembly and reduces the operating power losses. An explicit control strategy with enhanced device efficiency is also acquired. Thus, the part count reductions enhance not only the economical merits but also the technical features of the entire system. In order to accomplish the desired operational aspects, three algorithms are considered to determine the magnitudes of the dc voltage sources effectively. The proposed topology is compared with the conventional cascaded H-bridge multilevel inverter topology, to reflect the merits of the presented structure. In continue, both the analytical and experimental results of a cascaded 31-level structure are analyzed. The obtained results are discussed in depth, and the exemplary performance of the proposed structure is corroborated.

An Optimal Procedure for Sizing and Siting of DGs and Smart Meters in Active Distribution Networks Considering Loss Reduction

T. Sattarpour,D. Nazarpour,S. Golshannavaz,P. Siano 대한전기학회 2015 Journal of Electrical Engineering & Technology Vol.10 No.3

The presence of responsive loads in the promising active distribution networks (ADNs) would definitely affect the power system problems such as distributed generations (DGs) studies. Hence, an optimal procedure is proposed herein which takes into account the simultaneous placement of DGs and smart meters (SMs) in ADNs. SMs are taken into consideration for the sake of successful implementing of demand response programs (DRPs) such as direct load control (DLC) with end-side consumers. Seeking to power loss minimization, the optimization procedure is tackled with genetic algorithm (GA) and tested thoroughly on 69-bus distribution test system. Different scenarios including variations in the number of DG units, adaptive power factor (APF) mode for DGs to support reactive power, and individual or simultaneous placing of DGs and SMs have been established and interrogated in depth. The obtained results certify the considerable effect of DRPs and APF mode in determining the optimal size and site of DGs to be connected in ADN resulting to the lowest value of power losses as well.

A New Design for Cascaded Multilevel Inverters with Reduced Part Counts

Reza Choupan,Daryoush Nazarpour,Sajjad Golshannavaz 한국전기전자재료학회 2017 Transactions on Electrical and Electronic Material Vol.18 No.4

This paper deals with the design and implementation of an efficient topology for cascaded multilevel inverters with reducedpart counts. In the proposed design, a well-established basic unit is first developed. The series extension of this unit resultsin the formation of the proposed multilevel inverter. The proposed design minimizes the number of power electroniccomponents including insulated-gate bipolar transistors and gate driver circuits, which in turn cuts down the size of theinverter assembly and reduces the operating power losses. An explicit control strategy with enhanced device efficiency is alsoacquired. Thus, the part count reductions enhance not only the economical merits but also the technical features of the entiresystem. In order to accomplish the desired operational aspects, three algorithms are considered to determine the magnitudesof the dc voltage sources effectively. The proposed topology is compared with the conventional cascaded H-bridge multilevelinverter topology, to reflect the merits of the presented structure. In continue, both the analytical and experimental results ofa cascaded 31-level structure are analyzed. The obtained results are discussed in depth, and the exemplary performance ofthe proposed structure is corroborated.