Kalman filter applied to Thevenin’s modeling of a lead-acid battery

<span>This article determines the internal parameters of a battery analyzed from its circuit equivalent, reviewing important information that can help to identify the battery’s state of charge (SOC) and its state of health (SOH). Although models that allow the dynamics of different types of batteries to be identified have been developed, few have defined the lead-acid battery model from the analysis of a filtered signal by applying a Kalman filter, particularly taking into account the measurement of noise not just at signal output but also at its input (this is a novelty raised from the experimental). This study proposes a model for lead-acid batteries using tools such as MATLAB^® and Simulink^®. First, a method of filtering the input and output signal is presented, and then a method for identifying parameters from 29 charge states is used for a lead-acid battery. Different SOCs are related to different values of open circuit voltage (OCV). Ultimately, improvements in model estimation are shown using a filter that considers system and sensor noise since the modeled and filtered signal is closer to the original signal than the unfiltered modeled signal.</span>

Microcontroller-Based Lead-Acid Battery Balancing System for Electric Vehicle Applications

In application of lead-acid batteries for electrical vehicle applications, 48 V of four 12 V batteries in a series configuration are required. However, the battery stack is repeatedly charged and discharged during operation. Hence, differences in charging and discharging speeds may result in a different state-of-charge of battery cells. Without proper protection, it may cause an excessive discharge that leads to premature degradation of the battery. Therefore, a lead-acid battery requires a battery management system to extend the battery lifetime. Following the LTC3305 balancing scheme, the battery balancing circuit with auxiliary storage can employ an imbalance detection algorithm for sequential battery. It happens by comparing the voltage of a battery on the stack and the auxiliary storage. In this paper, we have replaced the function of LTC3305 by a NUCLEO F767ZI microcontroller, so that the balancing process, the battery voltage, the drawn current to or from the auxiliary battery, and the surrounding temperature can be fully monitored. The prototype of a microcontroller-based lead-acid battery balancing system for electrical vehicle application has been fabricated successfully in this work. The batteries voltage monitoring, the auxiliary battery drawn current monitoring, the overcurrent and overheat protection system of this device has also successfully built. Based on the experimental results, the largest voltage imbalance is between battery 1 and battery 2 with a voltage imbalance of 180 mV. This value is still higher than the target of voltage imbalance that must be lower than 12.5 mV. The balancing process for the timer mode operation is faster 1.5 times compared to the continuous mode operation. However, there were no overcurrent or overtemperature occurred during the balancing process for both timer mode and continuous mode operation. Furthermore, refinement of this device prototype is required in the future to improve the performance significantly.

Spatial Heterogeneity of China’s Environmental Regulation on Industrial Pollution: Evidence from a Top–Down Environmental Enforcement Action

To obtain precise information about enterprises’ pollution control and take corresponding environmental protection measures is the key to preventing and controlling industrial pollution. Taking the lead–acid battery industry as an example, this paper employs data from the Environmental Enforcement Action to analyze the urban–rural and inter-provincial distributions of pollution-intensive enterprises and to quantitatively verify the spatial differences in China’s environmental regulation on industrial pollution. The study finds that lead–acid battery manufacturing enterprises are mainly located in rural areas instead of urban areas; most pollution-intensive firms located in industrial parks, especially those approved by governments below the provincial level. The multivariate logistic model analysis finds that environmental regulation in urban districts is more strict than that in towns and villages, while the suburban areas are the laxest; environmental regulation in national-level development zones is more strict than that in provincial-level development zones, while zones below the provincial level are the laxest. In general, the environmental regulation is stricter in urban areas than in rural areas, and stricter in clustered space than in scattered space, while most inter-provincial environmental regulations have no significant differences. Local governments should effectively allocate conventional environmental law enforcement resources and shift the focus of law enforcement downwards to parks below the provincial level, and on suburbs and townships.

Design of a Step-Up DC–DC Converter for Standalone Photovoltaic Systems with Battery Energy Storages

This paper proposes a step-up DC–DC converter for a power electronic circuit for standalone photovoltaic systems with battery energy storages. The proposed DC–DC converter effectively converts low DC battery voltage into high DC-link voltage. It operates with soft-switching characteristics, which can reduce switching power losses. The proposed converter operates without output voltage feedback, which simplifies its control design. The operation principle of the proposed converter was described, along with the overall system configuration. The experimental results were discussed for the 500-W prototype system using a 12-V lead-acid battery.

The Effect of Expanded and Natural Flake Graphite Additives on Positive Active Mass Utilization of the Lead-Acid Battery

The effects of expanded and not expanded (natural flake) graphite additives were evaluated on the discharge utilization of the positive active material (PAM) in the lead-acid battery. Graphite powders were added to the paste at 2.20 vol. % and tested in model 2V battery cells under a wide range of discharge currents from 8C to C/20. The effects of graphite on the PAM pore volume and pore size distribution were measured with mercury porosimetry, and a good correlation was found between the pore volume of the PAM and utilization performance of the cells. It was shown that the powder characteristics of graphite can affect the PAM pore volume. A correlation was found between the graphite additives’ structural order and PAM utilization.