Analysis of semiconductor sensor for detecting dissolved gases in power transformers

Three hypotheses for steady-state responding, transient responding and resuming behavior of semiconductor gas sensors are proposed, according to which, the logarithm of the steady-state resistance value and the logarithm of the gases concentration obey a tangent function; the transient response is decided by the current resistance of the sensor and the gases concentration; and the resuming behavior is decided by the current resistance of the sensor and gases concentration at the next time. In order to validate the hypotheses, a gases separating function is modeled on the basis of stage model. Relative coefficients are obtained by experiment and mathematical methods. The gases separating model and the hypotheses about the sensor are validated by comparing the simulating results with the experiment results, and the comparing results show that the hypotheses are reasonable when applied in the semiconductor of the monitoring system for dissolved gases in insulating oil