Online control of energy storage system

• Main Author: Yan, Wei Liang
• Other Authors: Gooi Hoay Beng
• Format: Final Year Project
• Language: English
• Published: 2012
• Subjects: DRNTU::Engineering::Electrical and electronic engineering::Electric power::Production, transmission and distribution
• Online Access: http://hdl.handle.net/10356/49298
• Institution: Nanyang Technological University

Rechargeable batteries can be damaged due to overcharging and/or over-discharging. The degree of damage varies and in general, damages are irreversible and as a result, can cause a shorter lifespan to the battery. An accurate state-of-charge (SOC) estimation technique needs to be designed to protect rechargeable batteries from damages. Many research works are still studying and designing more accurate and reliable SOC estimation techniques. This trend is being excited by the advancement in microgrid industries as well as electric vehicles (EVs) which use rechargeable batteries heavily. In this project, a commercially available 5-kVA bi-directional energy storage controller is bought and a suitable SOC or state-of-discharge (SOD) estimation technique is to be designed and incorporated to the controller. The SOC estimation technique is developed using the open circuit voltage (OCV) method. The OCV algorithms are programmed in the LabVIEW graphical programming environment. Modbus protocol is used for its communication as it is simple and supported by the energy storage controller. Registers formatting is designed in the LabVIEW environment and simulations are proposed to test the accuracy of the SOC estimation technique. Simulations are also proposed for users to input/extract data to the controller and to make sure that correct data are written/read from the controller.