Concept Of Reactive Power Research Articles

PV Based Grid System for Power Quality Enhancement using Instantaneous P-Q Theory

The SPV interfaced grid system with battery storage unit, bidirectional VSI interconnected shunt active filter, an adaptive Proportional Integral (PI) controller is employed for improve current and voltage profile enhancement. The p-q theory is the common employed technique to extract the basic fundamental current harmonic components from affected or polluted power supply by means of diode rectifier or non linear load. The basic concepts of reactive power (IRP) theory includes it’s a time domain model and it can be applicable for both 3P3W and 3P4W. Initially, the control technique called instantaneous real and reactive power theory or p-q theory has been developed for three phase three wire system and then later it was extend to three phase four wire system. This system is valid under steady state as well as dynamic state. The bidirectional VSI based shunt APF is controlled by the PI based instantaneous reactive power theory. The proposed PI Controller interfaced shunt Active Power Filter is used to maintain DC-Link voltage.SPV system is interfaced with incremental conductance MPPT algorithm. This SAPF control scheme has to provide the following benefits like current harmonic mitigation as well as reactive power compensation

Power Quality Improvement of AC Distribution System using 3 Phase PV Integrated UPQC with Advanced Control Strategy

Renewable energy sources are used to accommodate the ongoing increasing power demand. So, the integration of PV system controlled by the revised p-q concept which is revealed from instantaneous active reactive power concept and a suitable choice to meet the energy demand. Enormous utilization of power electronic converters deviates the quality of power. Series voltage compensation and shunt current compensation is done by the p-q theory. Revised p-q conceptstates the single instantaneous active power and the imaginary powers for active and reactive power compensation. This paper presents the revised p-q concept to generate the reference signals for integrated unified power quality conditioner (PV-UPQC-S). This proposed method enables the process of PV-UPQC-S under unbalanced voltage circumstances at the point of common coupling (PCC). This system incorporates the series voltage source converter (VSC) to control the unbalanced voltage by sharing the part of the reactive power of the load, which in turn reduces the rating of the shunt VSC. The integration of the PV system at the DC bus of UPQC serves the purpose of load sharing as well as power quality improvement to maintain the healthy grid condition. This concept is approved by simulating the proposed model in MATLAB/Simulink. The proposed model comprises of both linear and non-linear loads. The experimental results validates the perfect dynamical response of the given model.

Selecting the parameters of a reactive-power compensator at nonlinear loads

The possibility of improving the parameters of a reactive-power compensator operating in nonsinusoidal modes has been studied by means of supplementary assessment of the design power of the compensator. It is based on the decomposition of the instantaneous power into components in the modes of phase shift of current relative to supply voltage. The temporal distortion of the curve of current is also studied. To date, numerous attempts have been done to generalize the concept of reactive power to nonsinusoidal processes or to introduce other general concepts, but these attempts have not led to the creation of a generally accepted theory that would adequately reflect energetic processes in the general case in the presence of distortions of current and voltage. This paper aims to increase the efficiency of reactive power-compensator equipment for agricultural and industrial consumers operating in nonsinusoidal modes. This is achieved by the use of supplementary computational procedures in the controlling algorithm of a reactive-power compensator. In this case, the transmission-line resistance and internal resistance of the power supply are taken into account.

AC 계통 무효전력 제어를 위한 HVDC 시스템 설계

This paper deals with the concept design of HVDC system for controlling AC network reactive power. HVDC system can active power and reactive power and the concept of reactive power is similar to SVC(Static Var Compensator). Reactive power is controlled by adjusting firing angle of HVDC system under the condition that AC filters are switched. Reactive power depends on AC voltage condition, considering the steady-state and transient state to maintain the stable operation of AC network in the viewpoint of voltage stability. Therefore, in the design stage of HVDC, the reactive power required in the AC network must be considered. For the calculation of operation angle in HVDC system, the expected reactive power demand and supply status is examined at each AC system bus. The required reactive power affects the determination of the operation angle of HVDC. That is, the range of control deadband of operation angle should have the capability supplying the required reactive power. Finally, the reactive power concepts is applied to 1GW BTB Pyeongtaek-Dangjin HVDC system.

Budeanu's Reactive Power and Related Concepts Revisited

This paper deals with the concepts of reactive power and reactive current in a nonsinusoidal periodic situation. It is shown that there exists a close relationship between the definitions proposed by Budeanu, Tenti, and Kusters and Moore. A new result is derived associated with the well-known Budeanu reactive power concept.

Considerations on a Reactive Power Concept in a Multiline System

The concepts of reactive power that originate from Buchholz's theory and are present in the IEEE Standard 1459 are important in compensation theory. It is shown in this paper that some misconceptions are present in the technical literature, in particular regarding the relationship between reactive power and power oscillation. In this paper, a number of examples are given to illustrate these misconceptions.

Power system analysis using space-vector transformation

In this paper, the space-vector transformation used in machine vector control is applied to power system analysis. The proposed method is used to model electric machines, power electronic converters, transformers, and transmission lines and to analyze power sources and loads with different connections (delta and wye). This method can also be applied to analyze steady-state (or transient phenomena) and unbalanced sources, including harmonics. Models obtained with this method are as simple as those of the per-phase approach. With the space-vector transformation, instantaneous active and reactive power concepts can be generalized, and new power system control strategies can be developed when power electronic converters are used. Steady-state, transient behavior, and harmonic analyses examples and applications are presented to illustrate the performance and advantages of the proposed method. This method can be extended to unbalanced systems (e.g., unsymmetric faults) using instantaneous symmetrical components in polyphase balanced circuits.

Power System Analysis Using Space Vector Transformation

The space vector transformation used in machine vector control is applied to power system analysis. The proposed method is used to model electric machines, power electronic converters, transformers, and transmission lines and analyze power sources and loads with different connections (delta and wye). this method can also be applied to analyze steady-state or transient phenomena and unbalanced sources, including harm, onics. Models obtained with this method are as simple as those of the per-phase approach. With the space-vector transformation, instantaneous active and reactive power concepts can be generalized, and new power system control strategies can be developed when power electronic converters are used. Steady-state, transient behavior, and harmonic analyses examples and applications are presented to illustrate the performance and advantages of the proposed method. This method can be extended to unbalanced systems (e.g., unsymmetric faults) using instantaneous symmetrical components in polyphase balanced circuits.

About the role of the park imaginary power on the three‐phase line voltage drop

AbstractIn this paper the line voltage drop concept is investigated and extended to non‐sinusoidal conditions. The results are applied to the three‐phase configuration. In this approach the presence of harmonic and sequence components is taken into account. The formal invariance of the obtained results with respect to the original single‐phase relationships is ensured by means of the three‐phase rms concept. The Park transformation is used as well, so that the three‐phase relationships are reduced to a simpler formal single‐phase approach: the simultaneous contributions of harmonic and sequence components are unified in a single formulation. Therefore the Park imaginary power role results as a natural extension of the usual single‐phase reactive power concept.

The mean generalized content: a conservative quantity in periodically‐forced non‐linear networks

AbstractNon‐linear networks working in periodical non‐ sinusoidal steady state are investigated. By means of a new balanced quantity, theorems and conditions are achieved about some aspects in the harmonic generation and in the power conversion at different frequencies. An extension of the concept of reactive power emerges too. A numerical example is discussed in details and relevant results are reported.

Reactive power - real or imaginary?

No matter how abstract the concept of reactive power is, requiring as it does the use of `imaginary' algebra to calculate, it plays a vital role in the stable operation of power systems. The author explains what reactive (or imaginary) power is and its effects on components and generator design. The author then discusses the early generator developments of Charles Parsons, high voltage transmission, reactive power control in transmission systems, and measurement of reactive power.

Analytical investigation of the flattening effect: The reactive power balance rule

McIntyre et al. [J. Acoust. Soc. Am. 74, 1325–1345 (1983)], through comprehensive time-domain analyses of the bowed string mechanisms and various numerical simulations, have first pointed out that the hysteretical character of the sticking–slipping process necessarily induces, under certain end conditions, a flattening effect (the note plays flat as the bow pressure exceeds a given level). Taking advantage of a frequency-domain analysis, it is demonstrated that the area of the hysteresis cycle has an analytical relation to various physical parameters of the bowed string, leading to the concept of reactive power. The flattening effect appears as a consequence of this relation. Another possible consequence is the observed dependence of the spectrum and intensity of the string vibration on the bow pressing force. Based on realistic assumptions, an algorithm is proposed to connect the flattening effect or the intensity variations to the physical characteristics of the string. Finally, the variations of the flattening effect with playing parameters such as bow position or bow velocity are evaluated.

Reactive Power Concepts in Need of Clarification

To assist in clarifying the present concepts of reactive power, the following introduction to the subject has been prepared. An analysis of the reactive conventions made by Doctor Silsbee, a member of the subcommittee, is included.

I — Reactive power concepts in need of clarification

To assist in clarifying the present concepts of reactive power, the following introduction to the subject has been prepared. An analysis of the reactive conventions made by Doctor Silsbee, a member of the subcommittee, is included.