FREQUENCY DETERMINATION OF HIGH-FREQUENCY LINK FOR PERCPECTIVE ELECTRIC ROLLING STOCK

• Main Author: D. O. Zabarylo
• Format: Article
• Language: English
• Published: Dnipro National University of Railway Transport named after Academician V. Lazaryan 2014-12-01
• Series: Nauka ta progres transportu
• Subjects: asynchronous tractive motor; double feed electric rolling stock; high-frequency transformer; IGBT; autonomous voltage inverter; high frequency link
• Online Access: http://stp.diit.edu.ua/article/view/30448/28038

Purpose. Total mileage of Ukrainian electric railways is distributed approximately equally between the areas of direct and alternating current. A double system of electric rolling stock is used to pass jointing places of different current kinds without train’s stop. Therefore introduction of such rolling stock of a new concept that is using an asynchronous traction drive is prospective for Ukrainian railways. Apart from advantages a rolling stock of similar concept has significant disadvantages, it is pulse energy consumption from the power supply, and it can affect the reliability of track automatic devices, and consequently, the train traffic safety. In addition the specific power of traction transformer is considerably inferior to the power density of other traction elements. The promising schemes using an intermediary link of increased frequency, which consist of a transformer and inverter, have been proposed for disadvantages amendments. The main task for the further introduction of prospective circuit is to determine the operating frequency for high frequency link. Methodology. The method of thermal parameters calculation of semiconductor devices has been used for determination switching transistors of maximum operating frequency. To obtain analytical expressions curves of energy, released during the IGBT (insulated-gate bipolar transistor) switching from its current load approximation method is used. Findings. The permissible frequency of low-frequency link is determinated by load current of intermediate transformer. Operating frequency range of a link depending on load current has been determined. A comparative analysis of the switching characteristics of 65 class IGBT production by companies Infineon and ABB has been performed. Originality. The further determination method of the maximum operating frequency of intermediate link for circuit with high-frequency transformer has been developed. Practical value. The established operating frequency range of the high-level link will develop further research of tractive circuit with high-frequency transformer use for double feed electric rolling stock with asynchronous tractive drive. It will evaluate the introduction effectiveness of similar configuration circuits.