scholarly journals Origins of the equivalent circuit concept: the voltage-source equivalent

2003 ◽  
Vol 91 (4) ◽  
pp. 636-640 ◽  
Author(s):  
D.H. Johnson
Keyword(s):  
Equivalent Circuit ◽  
Voltage Source ◽  
Source Equivalent

scholarly journals Comparison of one and two time constant models for lithium ion battery

2020 ◽  
Vol 10 (1) ◽  
pp. 670
Author(s):  
B. V. Rajanna ◽  
Malligunta Kiran Kumar
Keyword(s):  
Lithium Ion Battery ◽  
Equivalent Circuit ◽  
Equivalent Circuit Model ◽  
Lithium Ion ◽  
Constant Current ◽  
Voltage Source ◽  
Maximum Output ◽  
Output Error ◽  
Battery Model ◽  
Simulation Results

The fast and accurate modeling topologies are very much essential for power train electrification. The importance of thermal effect is very important in any electrochemical systems and must be considered in battery models because temperature factor has highest importance in transport phenomena and chemical kinetics. The dynamic performance of the lithium ion battery is discussed here and a suitable electrical equivalent circuit is developed to study its response for sudden changes in the output. An effective lithium cell simulation model with thermal dependence is presented in this paper. One series resistor, one voltage source and a single RC block form the proposed equivalent circuit model. The 1 RC and 2 RC Lithium ion battery models are commonly used in the literature are studied and compared. The simulation of Lithium-ion battery 1RC and 2 RC Models are performed by using Matlab/Simulink Software. The simulation results in his paper shows that Lithium-ion battery 1 RC model has more maximum output error of 0.42% than 2 RC Lithium-ion battery model in constant current condition and the maximum output error of 1 RC Lithium-ion battery model is 0.18% more than 2 RC Lithium-ion battery model in UDDS Cycle condition. The simulation results also show that in both simple and complex discharging modes, the error in output is much improved in 2 RC lithium ion battery model when compared to 1 RC Lithium-ion battery model. Thus the paper shows for general applications like in portable electronic design like laptops, Lithium-ion battery 1 RC model is the preferred choice and for automotive and space design applications, Lithium-ion 2 RC model is the preferred choice. In this paper, these simulation results for 1 RC and 2 RC Lithium-ion battery models will be very much useful in the application of practical Lithium-ion battery management systems for electric vehicle applications.

scholarly journals Theory on Another Type of Temperature-Independent Superconductivity Based on Circuit Approaches with High Critical Current Density

2019 ◽  
Author(s):  
Shinichi Ishiguri
Keyword(s):  
Wave Function ◽  
Critical Current Density ◽  
Equivalent Circuit ◽  
Critical Current ◽  
Current Density ◽  
Current Source ◽  
Meissner Effect ◽  
Voltage Source ◽  
High Critical Current Density ◽  
Negative Voltage

This paper proposes a method to generate a new type of superconductivity that is temperature independent with a high critical current density. This study is significant because the method does not require refrigeration, specific setups, or specific substances. That is, the method for generating the superconductivity is very simple. Many conventional superconductor studies have not yet reached this point. Moreover, compared with our previously developed superconductivity (PNS) [1-3], the critical currents in this study are much larger, which is important for practical applications. In the theoretical approaches, even though the mechanism of pairing, and the Bose–Einstein condensation are the same in this study as in PNS, the present paper emphasizes the mechanism of the Meissner effect in addition to formulating the critical current density. Further, we establish a simulation method with an equivalent circuit that reveals the superconductivity properties in terms of the transport current and the electromagnetic characteristics.The principles of the presented system are as follows:First a voltage source, a current source and a load are connected in series.Then, the voltage of the voltage source is adjusted to balance the voltage of the load.Under this condition, the balance of the two voltages provides a zero voltage between the taps of the current source and the generated current from the voltage source becomes zero because of the internal infinite resistance of the current source.As a result, the electric power generated by the two sources is zero, and therefore, the load cannot generate Joule heating because of energy conservation.However, the current from the current source (not the voltage source) is not zero; therefore, we can predict that the resistance of the load must be zero.A summary of our theory and numerical calculations is as follows. First, the strong combination of a two-electron pair is demonstrated. Then, given that two electrons combine extremely strongly because of the spin magnetic attractive force, analytical calculations of the center-of-mass motion of the Hamiltonian of the pair eventually result in a macroscopic wave function. From this macroscopic wave function, we derive a London equation using the concept of an internal toroid. The key point is that, when a sample exhibits a Meissner effect, it should release the additional energy from the internal magnetic field as a discharge current, which involves a negative voltage. Based on the inductance of this toroid, an equivalent circuit is produced. Using this circuit, we simulate this phenomenon, which results in the generation of a negative voltage and evidence of the Meissner effect, in addition to zero voltages and non-zero currents for the sample.

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