Due to the lack of flexible interconnection devices,power imbalances between networks cannot be relieved effectively.Meanwhile,increasing the penetration of distributed generators exacerbates the temporal power imbala...Due to the lack of flexible interconnection devices,power imbalances between networks cannot be relieved effectively.Meanwhile,increasing the penetration of distributed generators exacerbates the temporal power imbalances caused by large peak-valley load differences.To improve the operational economy lowered by spatiotemporal power imbalances,this paper proposes a two-stage optimization strategy for active distribution networks(ADNs)interconnected by soft open points(SOPs).The SOPs and energy storage system(ESS)are adopted to transfer power spatially and temporally,respectively.In the day-ahead scheduling stage,massive stochastic scenarios against the uncertainty of wind turbine output are generated first.To improve computational efficiency in massive stochastic scenarios,an equivalent model between networks considering sensitivities of node power to node voltage and branch current is established.The introduction of sensitivities prevents violations of voltage and current.Then,the operating ranges(ORs)of the active power of SOPs and the state of charge(SOC)of ESS are obtained from models between networks and within the networks,respectively.In the intraday corrective control stage,based on day-ahead ORs,a receding-horizon model that minimizes the purchase cost of electricity and voltage deviations is established hour by hour.Case studies on two modified ADNs show that the proposed strategy achieves spatiotemporal power balance with lower cost compared with traditional strategies.展开更多
A pressing challenge for China is determining where to accommodate millions of migrant workers displaced by the closing of many export-oriented factories. The current global financial crisis＂ has exposed the fragilit...A pressing challenge for China is determining where to accommodate millions of migrant workers displaced by the closing of many export-oriented factories. The current global financial crisis＂ has exposed the fragility of the export-led growth strategy China has adopted over the past 30years. Is there a better alternative for providing non-agricultural jobs than the sweatshops of cheap export production？ In the present paper, international experience is reviewed to shed light on China＇s situation. Using pooled regression models, we analyze data from the World Bank for 209 economies. We investigate the experience of other economies to answer the following questions： What is the common process of expanding the nonagricultural economy？ How is that process affected by the level of the real exchange rate？ Is export production a common way of absorbing surplus rural labor？ Finally, what are the ways that domestic demand and service employment can be expanded？展开更多
基金supported by the Science and Technology Project of State Grid Corporation of China(No.5400-202199281A-0-0-00)。
文摘Due to the lack of flexible interconnection devices,power imbalances between networks cannot be relieved effectively.Meanwhile,increasing the penetration of distributed generators exacerbates the temporal power imbalances caused by large peak-valley load differences.To improve the operational economy lowered by spatiotemporal power imbalances,this paper proposes a two-stage optimization strategy for active distribution networks(ADNs)interconnected by soft open points(SOPs).The SOPs and energy storage system(ESS)are adopted to transfer power spatially and temporally,respectively.In the day-ahead scheduling stage,massive stochastic scenarios against the uncertainty of wind turbine output are generated first.To improve computational efficiency in massive stochastic scenarios,an equivalent model between networks considering sensitivities of node power to node voltage and branch current is established.The introduction of sensitivities prevents violations of voltage and current.Then,the operating ranges(ORs)of the active power of SOPs and the state of charge(SOC)of ESS are obtained from models between networks and within the networks,respectively.In the intraday corrective control stage,based on day-ahead ORs,a receding-horizon model that minimizes the purchase cost of electricity and voltage deviations is established hour by hour.Case studies on two modified ADNs show that the proposed strategy achieves spatiotemporal power balance with lower cost compared with traditional strategies.
文摘A pressing challenge for China is determining where to accommodate millions of migrant workers displaced by the closing of many export-oriented factories. The current global financial crisis＂ has exposed the fragility of the export-led growth strategy China has adopted over the past 30years. Is there a better alternative for providing non-agricultural jobs than the sweatshops of cheap export production？ In the present paper, international experience is reviewed to shed light on China＇s situation. Using pooled regression models, we analyze data from the World Bank for 209 economies. We investigate the experience of other economies to answer the following questions： What is the common process of expanding the nonagricultural economy？ How is that process affected by the level of the real exchange rate？ Is export production a common way of absorbing surplus rural labor？ Finally, what are the ways that domestic demand and service employment can be expanded？
