Low-power Technology Research On Active Fiber DC Transducer

In the wake of rapid expansion of HVDC technology, the requirement of itsmeasurement equipments is more and more high. Photoelectric sensors with optical fibersensor technology become primary measurement equipments at present; it is applied to actualmeasurement. But the problem of loss in the high-voltage side is always a key and difficultpoint in the aspect of sensor design. This paper will carry out the analysis and research on lowloss technology of active optical fiber direct current sensor.This paper analyzes and compares with measured methods of high-voltage direct current,it designs an active optical fiber direct current sensor which is consist of shut and supplyingpower source with laser in the high-voltage side. When this paper conducts the first converterdesign with the low power loss, it adopts two kinds of switch schemes, one is based on V/F,and the other is based on A/D. In addition, it respectively puts forward kinds of differentsolutions for the above switch schemes.This paper adopts a scheme which applies discrete components to construct V/Fconversion circuits, when power source is6.5V, the maximum of power loss in thehigh-voltage side is0.715mW; The first converter that artificial circuit implements is easilyaffected by temperature and noise, so it is not suitable for outdoor environments; Under thecondition of integrated circuits of V/F conversion mode and power source is5V, themaximum of power loss in the high-voltage side is48.6mW; As a result of the V/Fconversion plan response slowly, the scheme of A/D switch can solve the problem. Inaddition, this paper adopts MSP430MCU with12AD converter and completes constructionof prototype. The MSP430chip of TI Company is a low-power-loss microcontroller; itconducts data acquirement and analysis through low power-loss consumption encoding andperipheral circuit design. The results show that in the scheme, the power loss of system in thehigh-voltage side less than50mW. The linearity of the whole system is better than0.5%.This paper completes hardware design and software design of system, it not onlyconstructs experiment prototype, but also it conducts theoretical software simulation. Inaddition, it carries out analysis of experiment data for power loss in the high-voltage side,aiming at active optical fiber direct current sensors which adopt different schemes. Finally, itsums up the whole work and looks forward to the design of low power loss.