-
[show abstract]
[hide abstract]
ABSTRACT: A novel fast-diagnostic method for open-switch faults in inverters without sensors is proposed to improve the reliability of power electronic system in this paper. The presented method is achieved by analysis of switching function model of the inverter under both healthy and faulty conditions. Due to the different voltages endured by each power switch under healthy condition from open-switch faults in some cases, open-circuit faults can be detected by sensing the collector-emitter voltages of the lower power switches in each leg. The diagnostic scheme employs the simple hardware circuit to obtain indirectly the voltages of lower power switches and to get rid of high cost and complexity as a result of sensors. Also, this method minimizes the detection time and is available for the inverter faults in the systems with open-loop or closed-loop current control strategies. To ensure the effectiveness and reliability of the proposed diagnostic method, the rising-edge delays for switching signals are used to avoid misdiagnostic results because of the ON-OFF processes of power switches, and the delay durations are determined considering various factors. Simulation and experimental results validate the proposed scheme for detecting switch and leg open-circuit faults.
IEEE Transactions on Power Electronics 02/2011; · 4.65 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: IGBT is widely applied in converter circuit because of its highly switching speed and easy driving, which brings severe electromagnetic interference (EMI). High and low of the gate drive circuit performance affects the level of EMI. This paper proposed a novel three stage gate control technology for IGBT. It is based on an optimal combination of several requirements necessary for good switching performance under snubberless operation conditions. The control scheme specifically combines together the slow drive requirements for low electromagnetic interference and switching stress and the fast drive requirements for high-speed switching and low switching losses. The gate drive can also effectively dampen current and voltage oscillations generated during turn-on and turn-off respectively. This paper looks at the conflicting requirements of the conventional gate drive circuit design and demonstrates using experimental results that the proposed three-stage gate drive scheme obtains an optimal between switching speed, power dissipation and electromagnetic interference
Industrial Electronics and Applications, 2006 1ST IEEE Conference on; 06/2006
-
[show abstract]
[hide abstract]
ABSTRACT: A PWM inverter fed AC induction motor drive system capable of suppressing all the adverse effects of PWM inverter is developed in this paper. A passive electromagnetic interference (EMI) filter is proposed, designed, and tested for a 4-kW drive system, is characterized by sophisticated connection of two small passive filters can compensate for common mode voltages produced by PWM inverter and can suppress leakage current. An equivalent common-mode circuit for the drive system equipped with the EMI filter is derived from experimental waveforms along with theoretical discussions verifies that the EMI filter is viable and effective in eliminating all adverse effects of PWM inverter
Industrial Electronics and Applications, 2006 1ST IEEE Conference on; 06/2006
-
[show abstract]
[hide abstract]
ABSTRACT: PMSM servo-system is introduced in this paper, and a double closed-loop control system with the current and speed loop is applied. The speed controller adopts compound control strategy with parameter self-adjust fuzzy control and PI control. At the same time, the current loop adopts PI control. Considering the dynamic performance of PMSM, the vector control and SVPWM is employed. The experiment results show that this control system possesses good dynamic and static performance, such as quick response and strong robustness
Intelligent Control and Automation, 2006. WCICA 2006. The Sixth World Congress on;
-
[show abstract]
[hide abstract]
ABSTRACT: In order to suppress the oscillation of gate drive signal of the power MOSFET, a equivalent circuit model of the half-bridge inverter considering stray parameters of the drive circuit is put forward based on the equivalent model of the power MOSFET considering junction capacitances, based on which it is known that the oscillation is caused by the high dv/dt produced during the power MOSFET switching and junction capacitances and distributed inductance. The drive circuit parameters are devised optimally according to the transient timing domain three-dimensional curves of parameters corresponding to the oscillation. The oscillation is suppressed obviously through increasing turn-on time of the power MOSFET, and experimental results are given. Both the theoretic analysis and experimental results indicate that the improved circuit can meet the power MOSFET drive requirement perfectly
Intelligent Control and Automation, 2006. WCICA 2006. The Sixth World Congress on;
