Wang Li-dong

Bio: Wang Li-dong is an academic researcher. The author has contributed to research in topics: Thermoelectric cooling & TEC. The author has an hindex of 1, co-authored 1 publications receiving 2 citations.

Effect of thermoelectric coolers on temperature control of SLD

Abstract: Aiming at the poor matching between SLD and its control circuits,this paper analyzes the effects of SLD's semiconductor cooler on discretization of temperature control parameters and gives the solving methods.Results indicate that: 1) the main reasons of parameter discretization are the characteristics of equivalent resistance and cooling efficiency of TEC;2) Under the present temperature control mode,the equivalent resistance of TEC is the most important reason of parameter discretization,depending on techniques and conditions;3) The cooling and heating efficiency of TEC may accelerate or prevent dispersing of temperature control parameters.Changing the mode of temperature control,building the standard management of SLD,improving the consistency of TEC,and increasing the cooling efficiency of TEC would improve the match effects between SLD and its control circuits.

Effect of spherical nonuniform distribute magnetic field on FOG

Abstract: Using matrix optics and optical propagation theory, a model for bias errors of an optical fiber gyroscope (FOG) caused by the spherical nonuniform distribute magnetic field has been deduced. Based on the above model, the effect on the FOG caused by the nonuniform distribute magnetic field and common circuit board is also analyzed. Results indicate that, i) the nearer of distance between the center of magnetic field and the fiber loop, the bigger of the bias errors of FOG will be; ii) relationship between bias and magnetic field direction is a inclined sine; iii) outside of the loop, the bigger of the height H0, the smaller of the bias error will be; iv) inside of the loop, the bias error is independent on the height H0; v) the common circuit board which radiate intensity is very weak can also cause unstable and direction related of the FOG’s output. Abolve conclusions may be useful for understanding the effect of actual magnetic field.

Effect on FOG caused by non-uniform distribute magnetic field

Abstract: Using matrix optics and optical propagation theory, a model for bias errors of an optical fiber gyroscope (FOG) caused by the nonuniform distribute magnetic field has been deduced. Based on the above model, the effect on the FOG caused by the nonuniform distribute magnetic field and common circuit board is also analyzed. Results indicate that, ⅰ) the nearer of distance between the center of magnetic field and the fiber loop, the bigger of the bias errors of FOG will be; ⅱ) relationship between bias and magnetic field direction is a inclined sine, which becomes more gradient when the distance between the center of magnetic field and the fiber loop is nearer; ⅲ) the bias error caused by the nonuniform magnetic field is bigger than that caused by uniform magnetic field of equal intensity, when R < 5r ( center of nonuniform magnetic field in fiber loop) or R < 0.5r ( center of nonuniform magnetic field out of fiber loop); ⅳ) the direction of magnetic axis is changed by the exit of nonuniform magnetic field; ⅴ) the common circuit board which radiate intensity is very weak can also cause unstable and direction related of the FOG’s output. Above conclusions may be useful for understanding the effect of actual magnetic field.

Analysis on the Influence of SLD’s Optical Power on the Performance of Fiber Optic Current Transformer

Abstract: As one of the core components of fiber optic current transformer (FOCT), the optical source has a crucial influence on the performance of FOCT. Super luminescent Diode (SLD) is an ideal optical source for FOCT because of its high output power, low coherence and wide spectrum. However, in the long-term operation process, the output optical power attenuation of SLD is inevitable. Based on the first-order system model of FOCT with closed-loop control, the influence model of SLD’s output optical power on the key performance of FOCT is established. The influence of optical power attenuation on the measurement error, measurement bandwidth, output signal-to-noise ratio (SNR) and step response of FOCT is simulated and analyzed. The simulation results show that the optical power attenuation of SLD is the main influence factor the phase error of FOCT, and the central wavelength drift caused by optical power attenuation is the key influence factor the FOCT ratio error. In order to meet the technical requirements of current transformer level 0.2, the optical power attenuation of SLD should not exceed 10%. The simulation analysis results have guiding significance for putting forward a reasonable method to stabilize the output optical power of SLD and improving the long-term reliable operation performance of FOCT.