Improving the Dynamic Performance of Distribution Electronic Power Transformers Using Sliding Mode Control

Abstract

These days, the application of electronic power transformers (EPTs) is expanding in place of ordinary power transformers. These transformers can transmit power via three or four wire converters. Their dynamic performance is extremely important, due to their complex structure. In this paper, a new method is proposed for improving the dynamic performance of distribution electronic power transformers (DEPT) by using sliding mode control (SMC). Hence, to express the dynamic characteristics of a system, different factors such as the voltage unbalance, voltage sag, voltage harmonics and voltage flicker in the system primary side are considered. The four controlling aims of the improvement in dynamic performance include: 1) maintaining the input currents so that they are in sinusoidal form and in phase with the input voltages so they have a unity power factor, 2) keeping the dc-link voltage within the reference amount, 3) keeping the output voltages at a fixed amount and 4) keeping the output voltages in sinusoidal and symmetrical forms. Simulation results indicate the potential and capability of the proposed method in improving DEPT behavior.

Adaptive Control of Solid State Transformer Using Type-2 Fuzzy Neural System

“…Although SSTs were first proposed by Mc Murray in 1970, the studies on these transformers has shown intense interest during the last 20 years [11]. The aim of all studies is to design a transformer which can carry out all the properties of classical transformers in a single circuit and consisting of completely semiconductor elements [1,5]. Moreover, the most important purposes of these studies are to obtain the following characteristics from the transformer structure: power factor correction, voltage sag/swell compensation, fault isolation, fixed output voltage.…”

Mathematical Basis of Sliding Mode Control of an Uninterruptible Power Supply

“…However, if f(x) is not continuous, then this definition allows us searching a solution for (6) in such a domain of x, where f(x) is not defined.…”

“…Consider (6) and assume that f(x) is defined almost everywhere on an open subset of n  . Assume also that f(x) is measurable, locally bounded and discontinuous.…”

“…Many have concluded that the presence of chattering makes sliding mode control a good theory game, which is not applicable in practice. In the next period the researchers invested most of their energy in chattering free applications, developing numerous solutions [4][5][6][7][8].…”

Power electronic transformer with adaptive PLL technique for voltage-disturbance ride through

“…It is found that the SPC is suitable for dealing with a full range of unbalanced loads under the condition where the input-stage current stress increases. Nonlinear and intelligent controllers such as an internal model controller, a sliding mode controller, and a neurofuzzy controller are adopted in [18][19][20] to improve PET performance.…”