State of charge

About: State of charge is a research topic. Over the lifetime, 12013 publications have been published within this topic receiving 201419 citations. The topic is also known as: SoC & SOC.

Digital twin for battery systems: Cloud battery management system with online state-of-charge and state-of-health estimation

Abstract: Battery management is critical to enhancing the safety, reliability, and performance of the battery systems This paper presents a cloud battery management system for battery systems to improve the computational power and data storage capability by cloud computing With the Internet of Things, all battery relevant data are measured and transmitted to the cloud seamlessly, building up the digital twin for the battery system, where battery diagnostic algorithms evaluate the data and open the window into battery’s charge and aging level The application of equivalent circuit models in the digital twin for battery systems is explored with the development of cloud-suited state-of-charge and state-of-health estimation approaches The proposed state-of-charge estimation with an adaptive extended H-infinity filter is robust and accurate for both lithium-ion and lead-acid batteries, even with a significant initialization error Furthermore, a state-of-health estimation algorithm with particle swarm optimization is innovatively exploited to monitor both capacity fade and power fade of the battery during aging The functionalities and stability of both hardware and software of the cloud battery management system are validated with prototypes under field operation and experimental validation for both stationary and mobile applications

Intelligent Distributed Generation and Storage Units for DC Microgrids - A New Concept on Cooperative Control without Communications Beyond Droop Control

Abstract: Low voltage dc microgrids have been widely used for supplying critical loads, such as data centers and remote communication stations. Consequently, it is important to ensure redundancy and enough energy capacity in order to support possible increments in load consumption. This is achieved by means of expansion of the energy storage system by adding extra distributed energy storage units. However, using distributed energy storage units adds more challenges in microgrids control, since stored energy should be balanced in order to avoid deep discharge or over-charge in one of the energy storage units. Typically, voltage droop loops are used for interconnecting several different units in parallel to a microgrid. This paper proposes a new decentralized strategy based on fuzzy logic that ensures stored energy balance for a low voltage dc microgrid with distributed battery energy storage systems by modifying the virtual resistances of the droop controllers in accordance with the state of charge of each energy storage unit. Additionally, the virtual resistance is adjusted in order to reduce the voltage deviation at the common dc bus. The units are self-controlled by using local variables only, hence, the microgrid can operate without relying on communication systems. Hardware in the loop results show the feasibility of the proposed method.

Automotive battery status monitor

Abstract: A vehicle storage battery is monitored to determine battery capacity, state of charge and certain fault conditions. The ambient temperature, battery voltage alternator/regulator output voltage and current to and from the battery are continuously measured. Current voltage (I-V) data is analyzed to determine the internal resistance and polarization of the battery. A determination is made regarding state of charge and fault conditions produced by corroded terminals and low electrolyte level. The low temperature starting limit is determined by comparing the battery's power output capability with starting power requirements of the vehicle. Data produced by the comparison are indicated on the dashboard of the vehicle.

Estimating the state of charge of a battery

Abstract: This brief considers the state of charge (SOC) estimation problem for electrochemical batteries. Using an electric circuit model of the battery given in the literature, it is shown how the open-circuit voltage (which is directly related to the SOC) can be estimated based on the terminal voltage and current measurements provided there is sufficient variation in the battery current.