No abstract

No abstract

It is important to improve the dynamic performance and the low-voltage ride-through (LVRT) capability of a grid-connected photovoltaic (PV) system. This paper presents synergetic control for the control of a grid-connected PV system. Modeling of a grid-connected PV system is described, and differential-algebra equations are obtained. Two control strategies are used in normal operation and during LVRT of a PV system. Practical synergetic controllers with two control strategies are synthesized. The mathematical expressions are derived for computing control variables. The design of the synergetic controllers does not require the linearization of the grid-connected PV system. A grid-connected PV system with synergetic controllers is simulated in Simulink surroundings. The control performance is studied in normal operation and during LVRT. Simulation results show that the synergetic controllers are robust and have good dynamic characteristics under different operation states.

This article classifies service into six typologies based on perceived risks and degree of customisation. From the literature, appropriate industries are selected for carrying out two studies. In the first study, interviews and observations were used to collect organisational perspective data needed for sorting out competency differences between frontline employees belonging to various service typologies. The second study, done from the perspectives of customers, adopts the use of questionnaires derived from Study 1. Of the 2060 questionnaires retrieved, 1120 valid questionnaires were obtained. Data were subjected to data triangulation, followed by a discussion and the proposal of managerial implications.

No abstract