State-Of-Charge Model Reference Estimator for a Battery Connected to a Step-Down Power Converter

In this article, a method for the efficient charging of electric vehicles (EVs) at the parking lot (PL) level, including V2G operation and taking into account lifetime of EV batteries, distribution network and local transformer loading, is proposed. The main targets of the method are to minimize the total charging cost of the PLs hosting the EVs and to satisfy all technical and operation constraints of EVs and PLs. The proposed method exploits particle swarm optimization (PSO) to derive the charging schedule of the EVs. The proposed method is compared with conventional charging strategies, where the EVs are charged with the maximum power of their charging power converter or the average power required to achieve their state-of-charge target, and a conventional charging scheduling method using the aggregated behavior of the plug-in EVs. Real-world data series of electricity price and parking lot activity were used. The results obtained from the study of indicative operation scenarios prove the effectiveness of the proposed method, while no sophisticated computing, measurement and communication systems are required for its application.

Download Full-text

Stability Analysis in Positive Output and Negative Output DC to DC Converters Used in Renewable Energy Applications

10.20944/preprints201911.0288.v1 ◽

2019 ◽

Author(s):

Maheswari Ellappan ◽

Kavitha Anbukumar

Keyword(s):

Renewable Energy ◽

Stability Analysis ◽

Output Voltage ◽

Monodromy Matrix ◽

Period Doubling ◽

Current Mode ◽

Power Converter ◽

Control Technique ◽

Step Down ◽

The Stability

The renewable energy source plays a major role in the grid side power production. The stability analysis is very essential in the renewable energy converters. In this paper the bifurcation is analyzed in ZETA converter and Continuous input and output(CIO) power Buck Boost converter. The ZETA converter gives positive step down and step up output voltage and the CIO power converter gives the negative step up and step down output voltage. These converters are used in the DC micro grid with renewable energy as the source. The current mode control technique is applied to analyze the bifurcation behavior and the reference current is taken as the bifurcation parameter. When the reference current is varied, both the converters loses its stability and it enters into chaotic region through period doubling bifurcation. The simulation results are presented to study the performance behavior of both the converters. The stability region of both the converters are determined by deriving the Monodromy matrix approach.

Download Full-text

The establishment and analysis of a state of charge model for lithium ion batteries

Modern Physics Letters B ◽

10.1142/s0217984918400602 ◽

2018 ◽

Vol 32 (34n36) ◽

pp. 1840060 ◽

Cited By ~ 1

Author(s):

Lin Yu ◽

Ming-Fang Liu

Keyword(s):

Fuzzy Inference ◽

Lithium Ion ◽

State Of Charge ◽

Prediction System ◽

Inference System ◽

Neuro Fuzzy ◽

Charge Model ◽

Battery Packs ◽

Different Temperatures ◽

Residual Capacity

Based on the rebound voltage data which was measured under different temperatures for lithium ion battery, a residual capacity prediction model used adaptive neuro-fuzzy inference system (ANFIS) was established. The rebound voltage and temperature were the input of prediction system, and the output was residual capacity. A large number of experimental data were used to train and verify the model. The reliability and applicability of the model were proven by applying it to predict and verify the residual capacity of different battery packs.

Download Full-text