Device and method for detecting storage battery

Abstract

The invention discloses a device for detecting a storage battery, comprising a CPU, an operational amplifier, a multi-way switch, a digital / analog (D / A) converter, a high-power MOS tube, a coupling capacitor, a programmable bandpass filter and an analog / digital (A / D) converter. The high-power MOS tube is connected on a storage battery discharge detection circuit in series. The CPU is used for controlling discharge of the storage battery so as to generate excitation current. The detected current signals and voltage signals are amplified by the operational amplifier after the coupling capacitorsubtracts the direct current component, and the signals are transmitted to the A / D converter to be changed into digital signals after the programmable bandpass filter gets rid of the interference signals, then the digital signals are transmitted to the CPU to be processed and complex impedance of the storage battery under the corresponding frequency can be obtained after arithmetical operation. The CPU can control the MOS tube via the D / A converter to change the waveform and frequency of the discharge current of the storage battery so as to realize measuring a plurality of frequencies of the storage battery. A detecting method using the device can be used for detecting the storage battery by an AC discharge method in multiple frequency points.

Description

technical field [0001] The invention relates to a detection device and method for a storage battery, in particular to a detection method and a device for detecting a storage battery by a multi-frequency point AC discharge method, and belongs to the technical field of detection. Background technique [0002] As an integral part of the power system, the battery plays a key role in storing electric energy, coping with abnormal and special working conditions of the power grid, and maintaining the normal operation of the system. It is the last line of defense in the field of high reliability power guarantee. Batteries are widely used in electric power, communications, government agencies, finance, securities, insurance, radio and television, transportation, manufacturing, military, education, scientific research, public facilities and other industries. However, in practical applications, due to the lack of effective detection and maintenance means, the state of the battery cannot...

AI Technical Summary

Problems solved by technology

[0004] (1), poor anti-interference, large measurement error

Due to the small injection current, the AC injection method is easily disturbed by the AC ripple and flicker of the charger, and the measurement error is large

[0005] (2) It can only be measured at one frequency, and the measured parameters are few, which cannot accurately reflect the state of the battery

[0007] 2. Defects of DC discharge method

Due to the use of a very large current, the discharge current often exceeds the design discharge current of the battery, so the measurement process will cause damage to the battery and connecting lines, and it is a destructive test method.

[0009] (2), endangering the safety of the power supply system

One is that the main circuit of the battery needs to be disconnected during the test, so it is necessary to switch in the main circuit. If the equipment fails, it will endanger the safety of the entire power supply system, and once a power failure occurs during the test, the backup power supply will be damaged. The switching and protection of the

In addition, excessive discharge current may interfere with the relay protection device, causing malfunction and endangering the safety of the power supply system.

[0010] (3) When the DC discharge method measures the internal resistance of the battery, polarization will occur on the internal electrodes of the battery, resulting in polarization internal resistance, resulting in a large error in the measured value of the internal resistance

[0011] (4), poor repeatability of measurement

The battery itself is a large capacitor, and the measurement circuit also has capacitance and inductance. Therefore, during the entire discharge process, especially at the beginning and end, the transient effect of the circuit is very obvious. In this way, the sampling value of the DC discharge method varies greatly at different times. Large, resulting in poor measurement repeatability

[0012] (2) It can only be measured at one frequency, and the measured parameters are few, which cannot accurately reflect the state of the battery

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