A Battery Dynamic Model for the Power System Simulation

2013 ◽  
Vol 805-806 ◽  
pp. 458-463
Author(s):  
Xiao Dong Li ◽  
Zhong Xing Dong ◽  
Wei Zong ◽  
Zong Qi Liu

This paper analyzes the battery dynamic characteristics as well as some existing battery models, then presents a universal battery model applicable to micro-grid simulation. The model is composed of a controlled voltage source in series with a constant resistance .The voltage of the controlled voltage source is a one-to-one correspondence with the state of charge (SOC) of the battery, which can effectively avoid the algebraic loop problem. The parameters of the model can be easily extracted from the battery discharge curve. The simulation results shows that the biggest advantage of this model is that the initial SOC of the battery can be set accordingly, which allows the battery to be charged or discharged from any SOC conveniently.

Alloy Digest ◽  
1981 ◽  
Vol 30 (9) ◽  

Abstract KANTHAL 70 alloy was designed to provide a high positive temperature coefficient to electrical resistance comparable with that of pure nickel; however, it has much higher electrical resistivity than pure nickel. This makes it useful as a voltage regulator when placed in series with another electrical device across a fluctuating voltage source. Kanthal 70 has a maximum recommended operating temperature of 600 C and is used widely in resistance thermometers and in various appliance and automotive applications. This datasheet provides information on composition, physical properties, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, and joining. Filing Code: Ni-270. Producer or source: The Kanthal Corporation.


Electronics ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 60
Author(s):  
Mario Ponce-Silva ◽  
Daniel Salazar-Pérez ◽  
Oscar Miguel Rodríguez-Benítez ◽  
Luis Gerardo Vela-Valdés ◽  
Abraham Claudio-Sánchez ◽  
...  

The main contribution of this paper is to show a new AC/DC converter based on the rearrangement of the flyback converter. The proposed circuit only manages part of the energy and the rest is delivered directly from the source to the load. Therefore, with the new topology, the efficiency is increased, and the stress of the components is reduced. The rearrangement consist of the secondary of the flyback is placed in parallel with the load, and this arrangement is connected in series with the primary side and the rectified voltage source. The re-arranged flyback is only a reductive topology and with no magnetic isolation. It was studied as a power supply for LEDs. A low frequency averaged analysis (LFAA) was used to determine the behavior of the proposed circuit and an equivalent circuit much easier to analyze was obtained. To validate the theoretical analysis, a design methodology was developed for the re-arranged flyback converter. The designed circuit was implemented in a 10 W prototype. Experimental results showed that the converter has a THDi = 21.7% and a PF = 0.9686.


Author(s):  
V. D. Pavlov ◽  

The use of the symbolic (complex) method has significantly simplified the study of resonance and near-resonance phenomena, in particular, it has made it possible to deeply unify and formalize the consideration of various mechanical systems. The cumbersome and time-consuming operations associated with composing and solving differential equations have been replaced by simple algebraic transformations. The method is based on the mechanical analogue of Ohm’s law in a complex representation and the concept of mechanical reactance, resistance, impedance, susseptance, conductance and admittance. Resonances and antiresonances of forces and velocities are determined. Resonances occur when the elements are connected in parallel with a force source, or when the elements are connected in series with a velocity source. Antiresonances occur when a parallel connection and a speed source are combined, or a serial connection and a force source are combined. These concepts are a generalization to mechanics of the concepts of «voltage source» and «current source» from theoretical electrical engineering. The closest to the source of speed in its properties is a crank-rocker (connecting rod) mechanism with a massive flywheel. The source of force corresponds more to the rod of the significantly smaller of the two connected pneumatic cylinders.


Author(s):  
P Anusha ◽  
B V Rajanna

High power demands are usually met by advanced power electronics converters in several large utility and electric drives applications. Applications from high power drives commonly uses solution based multi pulse and multilevel converters. A common DC link with atleast one voltage source converter (VSC) working with almost fundamental switching frequency are used in converters of multipulse type, and each output module is connected with the multipulse transformer in series. When compared to that of solution with single-VSC, Several VSCs generating different triggering pulses are adjused in order to achieve current injected with low specified total harmonic distortion (THD) with losses of abridged switching. Huge structure in complexity and expensive cost expenditure of the multipulse transformer is the major limitation of this scheme. DC link split capacitors in addition are eliminated by modifying the topology of the circuit. Thus, the independent voltages of the DC capacitor are controlled and decreased in number and the flow of third harmonic current component in the transformer is eliminated. The scheme of the designed controller is depending on the derived mathematical system model. Simulaion observation is used to check the scheme performance and efficiency in a detailed way with drive control technique.


Author(s):  
Madhusmita Patro ◽  
Kanhu Charan Bhuyan

<p>Power quality has become an important factor in power systems, for consumer and household appliances. The main causes of poor power quality are harmonic currents, poor power factor, supply voltage variations etc. A technique of achieving both active current distortion compensation, power factor correction and also mitigating the supply voltage variations at load side is compensated by unique device UPQC presented in this thesis. This concept presents a multi loop based controller to compensate power quality problems through a three phase four wire unified power quality conditioner (UPQC) under unbalanced and distorted load conditions. Here the UPQC is constituted of two voltage source converters (VSC) connected via power link. The series compensator is connected to the line in series and injects the voltage and thus compensates for voltage issues; whereas the shunt compensator injects current thus compensating for current issues, and is connected in shunt to the line. The voltage injection to the line uses an injecting transformer. The injection transformer is later replaced with injection capacitors, thus eliminating the drawback of conventional UPQC. In this way a good power quality is maintained.</p>


Author(s):  
Madhusmita Patro ◽  
Kanhu Charan Bhuyan

<p>Power quality has become an important factor in power systems, for consumer and household appliances. The main causes of poor power quality are har ue of achieving active current distortion compensation, power factor monic currents, poor power factor, supply voltage variations etc. A techniq correction and also mitigating the supply voltage variations at load side is compensated by unique device UPQC presented in this thesis. This concept presents a multi loop based controller to compensate power quality problems through a three phase four wire Unified Power Quality Conditioner (UPQC) under unbalanced and distorted load conditions. Here the UPQC is constituted of two Voltage Source Converters (VSC) connected via power link. The series compensator is connected to the line in series and injects the voltage and thus compensates for voltage issues; whereas the shunt compensator injects current thus compensating for current issues, and is connected in shunt to the line. The voltage injection to the line uses an ijecting transformer. The injection transformer is later replaced with injection capacitors, thus eliminating the drawback of conventional UPQC. In this way a good power quality is maintained</p>


2012 ◽  
Vol 433-440 ◽  
pp. 7281-7286
Author(s):  
Xiao Chen Wang ◽  
Jiang Ming Yang ◽  
Hong Mei Li ◽  
Feng Xiang Sun

Three phase voltage source PWM rectifier (VSR)’s indirect current control (ICC) strategy has good static performance, simple control steps and low cost. But bad dynamic performance is its inherent drawback. If this weakness is overcome, it is still valued. In this article normal ICC is deeply studied beginning with its mathematical model under synchronous rotating coordinate. It is indicated that its bad dynamic performance originates from bad current response. So an improving scheme adding compensation in series is brought out. Additionally a differential negative feedback loop of DC output voltage is added to limit the voltage overshoot. Lastly the control system’s computer simulation model is established by MATLAB and the simulating results prove that improved ICC makes great process in dynamic performance and has advantages of both indirect and direct current control (DCC).


2017 ◽  
Vol 34 (3) ◽  
pp. 140-148
Author(s):  
Zbigniew Magonski ◽  
Barbara Dziurdzia

Purpose The aim of this paper is to find the electrical representation of a solid oxide fuel cell (SOFC) that enables the application of typical exploitation characteristics of fuel cells for estimation of fuel cell parameters (for example, exchange current) and easy analysis of phenomena occurred during the fuel cell operation. Design/methodology/approach Three-layer structure of an SOFC, where a thin semi-conducting layer of electrolyte separates the anode from the cathode, shows a strong similarity to typical semiconductor devices built on the basis of P-N junctions, like diodes or transistors. Current–voltage (I-V) characteristics of a fuel cell can be described by the same mathematical functions as I-V plots of semiconductor devices. On the basis of this similarity and analysis of impedance spectra of a real fuel cell, two electrical representations of the SOFC have been created. Findings The simplified electrical representation of SOFC consists of a voltage source connected in series with a diode, which symbolizes a voltage drop on a cell cathode, and two resistors. This model is based on the similarity of Butler-Volmer to Shockley equation. The advanced representation comprises a voltage source connected in series with a bipolar transistor in close to saturation mode and two resistors. The base-emitter junction of the transistor represents voltage drop on the cell cathode, and the base-collector junction represents voltage drop on the cell anode. This model is based on the similarity of Butler-Volmer equation to Ebers-Moll equation. Originality/value The proposed approach based on the Shockley and Ebers-Moll formulas enables the more accurate estimation of the ion exchange current and other fuel cell parameters than the approach based on the Butler-Volmer and Tafel formulas. The usability of semiconductor models for analysis of SOFC operation was proved. The models were successively applied in a new design of a planar ceramic fuel cell, which features by reduced thermal capacity, short start-up time and limited number of metal components and which has become the basis for the SOFC stack design.


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