A Self-powered Optical Current And Voltage Sensor Based On FVOA

With the rapid development of hybrid optical current and voltage sensors,their applications in power industry are becoming more and more extensive.However,the shortcomings of hybrid optical current and voltage sensor are also becoming more and more obvious,such as complex structure and the requirement of power supply at the high voltage side,which restrict their development seriously.To solve this problem,this paper presents a FVOA based,self-powered optical current and voltage sensor.It's a type of the active optical current or voltage sensor,which relies on the electro-optic modulation characteristics of FVOA.It comprises home-designed light transmission module,optical receiving module,and laser power supply module.This sensor uses optical fiber as the transmission medium which could effectively avoid the electromagnetic interference,and can be used in harsh or extreme environment such as high voltage terminal.There is a built-in electro-optical modulator based on FVOA,the driving voltage modulates optical power of passing through the FVOA,and can be detected by the relation between the optical power and the voltage.An optical receiver detects the modulated the optical signal,from which the driving voltage applied to the FVOA is measured.This is the principle of the FVOA based optical current or voltage sensor.This sensor can be used to measure the current signal and the voltage signal,the heavy current and voltage can be converted to a low voltage by the sampling resistance and the voltage splitter respectively.It's necessary to apply a bias voltage to FVOA for a better performance,and thus a power supply in high voltage terminal is needed.However,FVOA needs very low electric power to operate,and it can get the needed bias voltage from its signal light source.Therefore,a dedicated laser for supplying electric power to the electronics on the HV side is thus no more necessary.This method effectively overcomes the shortcomings of power supply difficulty on the HV side as in conventional hybrid optical current sensors.This sensor can be used for real-time monitoring in fixed position and can be made into a portable detector due to its simple structure and convenient operation.This sensor has good response speed,high precision,low cost and good stability,presents a better performance compared with other current and voltage sensors.This sensor can perform best in the condition of 1550 nm light with 3?W power and 4.9V bias voltage,the voltage measuring range is 2.9V in this case,and the minimum error rate is about 0.01% and 2% respectively when measure the voltage and the current.