3-level 3-phase voltage-fed soft-switching inverter with new space voltage vector modulation scheme and its feasible evaluations
This paper presents of digitally-controlled 3-level 3-phase voltage source type soft switching IGBT inverter topology with two auxiliary active resonant DC link (ARDCL) snubbers which can operate under a condition of zero voltage switching (ZVS). Its operating principle and its related new instantaneous space vector allocation modulation method are proposed and discussed for telecommunication energy plants. The feasible performances of ARDCL-assisted soft switching inverter suitable for high power applications is illustrated and evaluated on the basis of simulation and experimental results as compared with the 3-level 3-phase hard switching inverter using IGBT power modules.
A large class of time-varying filters can be described via pseudo-differential operators belonging to the Hormander class OPS 0 0 , 0. The questions whether and how an input signal can be reconstructed from a known output lead to the problems of invertibility of pseudo-differential operators in that class and of (at least, numerical) solution of pseudo-differential equations. We are going to derive effective conditions for the invertibility for pseudo-differential operators with globally slowly varying symbols as well as for causal pseudo-differential operators, and we study the stability of the finite sections method with respect to time and frequency for these operators.