应用变频器使多台油泵软启动

如何实现用一台变频器使多台油泵软启动,其关键问题是逆变器与工频电源之间的双向切换。为了克服设备运行工况不稳定和电机二次启动冲击电流给电网带来的危害,必须实现平滑无冲击切换,这就要求切换的瞬间,逆变器输出电源的频率、相位、幅度与工频电网的频率、相位、幅度相一致。为实现平滑无冲击切换,研制出了单台切换器和适用于多台电机启动的配电线路及多台切换控制线路。切换器由相位鉴别器、幅度鉴别器、50周好检测电路、允许门电路、输出控制电路等五部分组成。经用户一年多实践证明,生产样机完全达到了设计要求,既保证了飞机加油又可进行油库装卸和输转作业,且从未出现故障。

Application of Frequency Converter to Soft Start Multiple Oil Pumps

The key to realize soft start of multiple oil pumps by using one frequency converter is two way switch over between reverse converter and operating frequency power. In order to counter the harmful problems to power networks caused by unstable equipment operation and surge current in the secondary startup of the mo tor, surge-free switch over must be realized, which requires a conformation between the frequency,phase and amplitude output from reverse converter and that in operating frequency power network. To realize surge-free switch over, developed are a change over switch and the distribution circuits and the multiswitch controlled circuits,which are suitable for multipump startup. It is proved by over one year applications by users that the prototype has met all the design requirements,and has guaranteed,without failure,fuel filling to the airplanes as well as loading,unloading and transfer operation in tank farm.