Method for measuring electrostatic capacity of supercapacitor and device thereof

Abstract

The invention discloses a method for measuring electrostatic capacity of a supercapacitor and a device thereof. The method comprises the steps that the supercapacitor is charged until voltage of the two ends of the supercapacitor reaches the rated voltage; charging is stopped, and discharging to a discharge loop connected with a sampling resistor R is performed so that the voltage of the two ends of the sampling resistor is acquired in real time; and the electrostatic capacity C of the supercapacitor is calculated according to the voltage of the two ends of the sampling resistor R. The device comprises a charging power supply, a voltmeter, the sampling resistor and a sampler. The voltmeter is connected in parallel with the two ends of the supercapacitor. A charging loop is formed by the charging power supply and the supercapacitor. The discharge loop is formed by the sampling resistor and the supercapacitor. The sampler is connected in parallel with the two ends of the sampling resistor. According to the method for measuring the electrostatic capacity of the supercapacitor and the device thereof, the method and the device have no relationship with stability of discharge current and have no requirement for the slope of a discharge curve so that measurement error of the electrostatic capacity can be reduced and measurement accuracy can be enhanced.

Description

technical field [0001] The invention relates to the field of electromagnetic measurement, in particular to a method and device for measuring the electrostatic capacity of a supercapacitor. Background technique [0002] Supercapacitor is an emerging energy storage device, which is a brand new capacitor based on the theory of interface electric double layer proposed by German physicist Helmholtz. Supercapacitors combine the advantages of conventional capacitors and batteries. Compared with batteries, since supercapacitors do not undergo chemical reactions during the energy storage process, and the energy storage process is reversible, they can be repeatedly charged and discharged hundreds of thousands of times, with fast charging and discharging speed, no pollution to the environment, and long cycle life. In addition, compared with traditional capacitors, supercapacitors can store a very large electrostatic capacity through the huge surface area and extremely small charge sep...

AI Technical Summary

Problems solved by technology

[0008] There are the following defects when using the constant current discharge method to measure the electrostatic capacity: (1) The discharge curve is a straight line in theory. In fact, due to the influence of internal resistance, self-discharge, etc., the slope of the voltage drop curve changes continuously during discharge, so the calculation of electrostatic capacity capacity, using the linear equation of formula (1) directly will produce errors; (2) Secondly, the constant current discharge method has higher requirements on the stability of the discharge current I, and it must be ensured that the current I remains constant during the entire discharge process. That is, when using formula (1) to calculate the electrostatic capacity, the current parameter I defaults to a constant

Due to the large electrostatic capacity of the super capacitor, the discharge process will last for a long time, and the load impedance of the loop cannot be guaranteed to remain unchanged during the discharge process, so the discharge current I is difficult to keep constant, which will have a certain impact on the accurate measurement of the electrostatic capacity

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