Valve Regulated Lead Acid Battery Internal Resistance Detection Based On Modern Signal Processing

Valve regulated lead acid batteries play an important role in many fields of life and production. When AC power is failure, valve regulated lead acid battery will timely supply electricity. Therefore, the stability of the system or data security is directly related to the performance of valve regulated lead-acid battery. With the expansion of the time and scope of application, more and more economic loss is caused by the unknown valve regulated lead acid battery failure. To solve this problem, research on battery management system has been paid more and more attention.Firstly, this paper analyzes the necessity of battery monitoring, introduce the development of battery management system. Then based on the research of battery monitoring principle, through the comparison and analysis of different detection methods, determine to study on the internal resistance detection method.The internal resistance detection method is to input a low frequency sinusoidal alternating current signal to the battery, then measure the battery voltage, and then calculates the resistance of the battery. The traditional methods usually measure the voltage signal of battery with lock-in amplifier technology, which is at a high hardware cost. In this dissertation, a novel battery internal resistance detection method based on Hilbert transform and Pisarenko harmonic decomposition is proposed, which uses the modern signal processing method instead of lock-in amplifier technology to measure the voltage signal to reduce the economic cost. Hilbert transform can detect the useful voltage signal under the interferences, and construct the complex frequency signal for Pisarenko harmonic decomposition. Pisarenko harmonic decomposition algorithm can estimate the amplitude of the voltage signal.The simulation results show that the battery internal resistance mesurement method based on Hilbert transform and Pisarenko harmonic decomposition can get a good result, which has obvious advantage of lower cost than hardware base traditional methods.