为了将高压充电电源的负载地与控制电路地进行电气隔离,使充电电源安全稳定工作,介绍了基于电压/频率,频率/电压转换原理的光纤隔离变换器在高压充电电源的高压测量单元中的运用。论述了电路的结构、工作原理、硬件设计等,并重点分析了隔离变换器的传输延时情况;给出了利用数字信号处理器(DSP)进行频压转换的一种方法。实际运行表明:该变换器线性度好,满足最高电压上升率为360V/s的充电电压测量要求。此隔离变换器隔离电压等级高,传输精度高,调试简单,可用于需要高压隔离的中低速控制系统中。
In order to isolate the control circuit of power supply from the ground of the load and ensure the power supply to work safely and reliably, the isolation converter of optical fiber based on the conversion principle of voltage to frequency and frequency to voltage, which is used in the measured circuit of the high voltage charging power supply, is introduced. The configuration of converter system as well as the principle and hardware design is described. The transmission delay of isolation converter system is analyzed in detail. In addition, a digitized method using the digital signal process (DSP) to achieve the conversion of frequency to voltage is put forward. The experimental resuits and the practical operation shows that the converter has high linearity and meets the measurement demands of the charging voltage whose maximum rate-of-climb is 360 V per second. This isolation converter has high voltage level, high transmission precision and easy operation, fits the control system which has middle or low speed and requires isolation of high voltage.