A Novel Approach to Accurately Determine the $t_{q}$ Parameter of Thyristors

Abstract

The continued use of high-voltage thyristor devices in industry and their increased use in high-voltage dc transmission systems call for more attention to the properties of these devices. One of the important thyristor parameters is their turn-off time tq, which can be a limiting factor when applying thyristors at elevated switching frequencies. Hence, the accurate measurement of tq and its variation versus the operating conditions remains a crucial task for thyristor converters operating at elevated switching frequencies. In this paper, a proper test circuit for measuring this parameter with a high level of accuracy has been designed and built. Owing to the test circuit specificity, the variation effects of several electrical and physical constraints, such as the forward current, I F , the reverse applied voltage, VR, the operating temperature, T o , and the ramp rate of the forward reapplied voltage, dV D /dt, on the t q parameter of Thyristors are also studied and analyzed based on the physics of semiconductor devices and associated simulations.

The Role of a Wiring Model in Switching Cell Transients: the PiN Diode Turn-off Case

“…All of the components are simulated as equivalent circuit models except the PIN diode. For this semiconductor device, the FEM model is used because a high level of accuracy is required to obtain simulation results across this component that are as close as possible to the experimental results [17]. The values of the doping concentration, N D , the width W of the low-doped base region, the ambipolar carrier lifetime in the low-doped region, , and the effective area, A, [18].…”

Study on the Influence of Inconsistent Valve Parameters on LCC-HVDC Commutation and Operation

“…The equivalent circuit of thyristor was given in references [29], [30]. The comprehensive test circuit of thyristor was proposed in reference [31] and the thyristor turn-off time test circuit is given in reference [32]. However, those references did not analyze commutation process combining with thyristor parameters as well as the inconsistency of valve and thyristor parameters.…”