Nonlinear compensation to enhance the input dynamic range in analog optical fiber links for the high current short circuit test

Abstract

Due to their galvanic insulation and EMI immunity properties, optical fiber links have been used in the transmitter-receiver system of an analog voltage measuring system at a high-power mid-voltage testing laboratory with a highly aggressive EMI environment. This paper introduces the application of a nonlinear compensation to limit the voltage range at the input of a voltage-controlled oscillator, which is used to produce the pulsed frequency modulation needed to transmit the analog signals over the optical fiber links. The proposed dynamic range compensation system is based on nonlinear circuits to accommodate the input range of the voltage-controlled oscillator. This approach increases the transient signal handling capabilities of the measuring system. This work demonstrates that the nonlinear compensated optical fiber approach yields a unique, electrically isolated, lightning-proof analog data transmission system, for remote measuring systems in the highly aggressive EMI environment of high-power test laboratories.

Nonlinear Companding Circuits With Thermal Compensation to Enhance Input Dynamic Range in Analog Optical Fiber Links

“…Special caution has to be applied to ensure complete electrical isolation before acquiring voltage signals and transmitting data to the control room for later processing [1]. However, the main problem is to preserve the integrity of signals which have to be transmitted without any distortion [2]. To solve this problem, a measurement system capable of measuring and carrying analog signals with a minimum added error (1%) and with sufficient amplitude for processing had to be developed.…”