A Scheme of Dynamic Voltage Restorer to Improve Power Quality in Large Scale Industrial Enterprises

Loads in large scale industrial enterprises are always various and complex, causing insecure power quality. Meanwhile, some sensitive loads or precise instruments demand for high power quality. When voltage flicker or harmonics occurs, dynamic voltage restorer (DVR) can be used to stabilize the load-side voltage, which is a good manner of improving power quality. The paper explains the load demand in large scale industrial enterprises, analyzes several common voltage compensation scheme of DVR, and comes up with another voltage compensation scheme of DVR applied for double power supply with double load. A Simulink model according to the new scheme is also built in MATLAB/Simulink to test its performance. Simulation results show that the proposed scheme can guarantee the load-side voltage stability, which is an effective scheme for managing power quality.

Barriers to the Growth of Small and Medium Scale Construction Enterprises in Ghana

The construction industry in most developing economies is dominated heavily by small and medium scale enterprises. These construction enterprises need to thrive in an extremely competitive business environment. Conversely, most of these small and medium scale construction enterprises (SMSCE) are fraught with a plethora of barriers that inhibit and threaten their growth and survival. This research sought to evaluate the critical barriers that affect the growth of SMSCEs in the Ghanaian Construction Industry. The quantitative research method was adopted using a structured questionnaire with variables that were identified through a comprehensive literature review. The survey questionnaire was administered to 400 respondents comprising 250 SMSCEs, 100 Local Authority Engineers, and 50 Consultants to elicit data based on the identified variables. The major findings established by the study as barriers to the growth of SMSCEs in Ghana are largely structured as financial/fiscal barriers, business development barriers, technical/technological barriers, corruption barriers, knowledge management barriers, project acquisition barriers. A guiding framework should be developed based on the barriers identified to aid the growth and survival of SMSCEs in Ghana.

The Growth Paths and Mechanisms of Chinese Private Enterprise

During the past forty years of reform and opening up,China’s private economy has made remarkable strides.This paper introduces start-up organizational processes into the study of elite mobility in emerging markets,exploring the relationship between the social origins of entrepreneurs and their entrepreneurial outcomes.Our research finds that the initial scale,growth rate and current size of enterprises established by elite entrepreneurs are larger than those of grassroots entrepreneurs.With the deepening of economic reform and the growth of the private economy,the social origins of large business owners generally tend to be elitist and the scale advantage of the enterprises set up by elite entrepreneurs,especially endogenous or inside-track entrepreneurs,is ever more striking.The expansion of such enterprises’superior position is mainly due to their initial advantages of scale;after the start-up period,the advantage conferred by their pace of growth does not increase synchronously.In order to promote the further development of the private economy and release its innovative potential,it is necessary to give full play to the government’s function of regulating market operations and correcting market failure,and thus actively creating a good business environment.