IEC 62576-2009 pdf Electric double-layer capacitors for use in hybrid electric vehicles – Test methods for electrical characteristics

3.1 9 pre-conditioning discharging and storage of a capacitor under specified ambient conditions (temperature, humidity, and pressure) before testing NOTE Generally, pre-conditioning implies that a capacitor is discharged and stored until its inner temperature attains thermal equilibrium with the surrounding temperature, before its electrical characteristics are measured. 3.20 voltage treatment voltage application before measurement of a capacitor’s electrical characteristics NOTE Generally, this treatment is applied to a capacitor that has been stored for a long time or to a capacitor whose history is not clear. 3.21 post-treatment (recovery) discharging and storage of a capacitor under specified ambient conditions (temperature, humidity, and pressure) after tests NOTE Generally, post-treatment implies that a capacitor is discharged and stored until its inner temperature attains thermal equilibrium with the surrounding temperature before its electrical characteristics are measured. 3.22 charging efficiency efficiency under specified charging conditions, and ratio (%) of stored energy to charge accumulated electrical energy. This value is calculated from the internal resistance of a capacitor NOTE Refer to Equation C.8 in Annex C. 3.23 discharging efficiency efficiency under specified discharging conditions, and ratio (%) of discharge accumulated electrical energy to stored energy. This value is calculated from the internal resistance of a capacitor NOTE Refer to Equation C.1 0 in Annex C.
4.1.4 Measurement After the setting as specified above, the voltage-time characteristics between capacitor terminals as shown in Figure 2 shall be measured. 4.1 .5 Calculation method for capacitance The capacitance C shall be calculated using Equation (1 ) based on the voltage-time characteristics between capacitor terminals obtained in 4.1 .4.
The test equipment shall be as specified in 4.1 .2. The test equipment shall be capable of constant current charging, constant voltage charging, constant current discharging, and continuous measurement of the current and the voltage between the capacitor terminals in time-series as shown in Figure 5. The test equipment shall be able to set and measure the current and the voltage by the accuracy equal to ±1 % or less. The power supply shall provide the constant charge current for the capacitor charge with 95 % efficiency, set the duration of constant voltage charge, and provide a discharge current corresponding to the specified discharge efficiency. The d.c. voltage recorder shall be capable of conducting measurements and recording with a 5 mV resolution and sampling interval of 1 00 ms or less.