| As an important member of the new energy vehicles, electric vehicle attracted people’s attention widely under the circumstances of the serious pollution of the environment and the exhaustion of the traditional energy. Electric vehicle has been focused on from propos ed but it has not been promoted for a long time because of the limitations of its way to charge. In this case, the electric vehicle DC charger came into being, and with its advantages of fast charging it was promoted widely. However, the verification regul ation of DC charger doesn’t have a national standard, and the measurement of it hasn’t been unified. Therefore, in this paper, a way to certificate the DC charger has been developed.In this paper, the algorithm of AC signal in the charging side and the measurement of the electrical energy in the output side have been focused on. Besides, based on the process of charging, the BMS of the EV have been simulated. The main content of this paper is as follows:(1) In order to measure the AC electric parameters, it is necessary to design an algorithm to measure the frequency of the AC signal. In this paper, the algorithm designed to measure the frequency is as follows. Firstly, it measured the frequency through three zero crossing spot. Then it revised the frequen cy through the phase error of the DFT to get the precise freque ncy. Finally, it is simulated in the MATLAB to realize the measurement accuracy of 10-5.(2) Based on the measurement of frequency, the error of discrete spectrum was designed and corrected. In this paper, an algorithm that based on the normalized error of non-integer sampling is designed to correct the discrete spectrum. It used the normalized error of frequency to correct the amplitude. Finally, it realized the accurate measurement under the Integral and non-integral frequency.(3) Researching on the method of measurement of DC signal. Measuring the sample value through simulating the DC signal with band-limited noise.Using the Watt-Second method to set up the system to measure the DC energy t hat the error within 0.05%. Choosing an EV charger in the lab to analyze the efficiency of this charger.Experiments were carried on both in the lab and the charging station. the AC algorithm and the DC system were both verified to reach the the aim. |
