Energy is the driving force of modern society and economic development, and the lifeline of the existence and reproduction of human life. The gradual depletion of traditional fossil energy has brought the energy crisis closer. China's energy industry will be a new and transformative new industry for the sustainable development of energy resources and environmental protection. Therefore, rationally adjusting the energy structure, vigorously developing renewable energy and other new energy sources, and taking a diversified clean energy development path are our society. The only way to sustainable development.
The microgrid is a new type of network structure, which is a system unit composed of a set of micro power supply, load, energy storage system and control device. The power sources in the microgrid are mostly distributed power sources with small capacity, that is, small units containing power electronic interfaces, including micro gas turbines, fuel cells, photovoltaic cells, small wind turbines, and energy storage devices such as supercapacitors, flywheels, and batteries. They are connected to the user side and have the characteristics of low cost, low voltage and low pollution. The development and extension of microgrid can promote large-scale access of distributed power and renewable energy, and achieve high-reliability supply of multiple energy sources. It is an effective way to realize active distribution network, making traditional power grids Smart grid transition.
1. The meaning and research dynamics of microgrid
At present, many countries in the world have carried out micro-grid research, and based on the actual problems of the domestic power system, put forward their respective micro-grid concepts and development goals. As a new technology field, the development of microgrids in different countries presents different characteristics.
1.1 Research on American Microgrid
The ERTS (ConsorTIumforElectricReliabilityTechnologySoluTIons) organization consists of research organizations such as the US Power Group and the Berkeley Lawrence National Laboratory. It has conducted special research on microgrid technology with funding from the US Department of Energy and the California Energy Commission. The basic concept of microgrid defined by CERTS: This is a collection of loads and micropower supplies. The micropower supply operates in a system that provides both electrical and thermal power, and most of these micropower supplies must be power electronic and provide the required flexibility to ensure operation in an integrated system that is controlled Flexibility enables the microgrid to act as a controlled unit for large power systems to accommodate the reliability and safety requirements of local loads. The microgrid defined by CERTS proposes a new approach to a distributed power access system that is completely different from the previous one. The traditional approach focuses on the impact of distributed power on network performance when considering distributed power access systems. When there is a problem with the power grid in the traditional way, it is necessary to ensure that the networked distributed power supply is automatically shut down to avoid adverse effects on the power grid. The microgrid defined by CERTS should be designed such that when the main grid fails, the microgrid and the main grid are seamlessly disjointed or run into islands. Once the fault is removed, it can be reconnected with the main grid. The advantage of this kind of microgrid is that it is regarded as a self-control entity in the power distribution system connected to it, ensuring the uninterrupted power supply of important users, improving the reliability of power supply, reducing feeder loss, and supporting local voltage. Correction effect. Therefore, the microgrid not only avoids some negative effects of traditional distributed generation on the distribution network, but also plays a certain supporting role for the distribution network of the microgrid access point.
1.2 European microgrid research
Europe proposes to make full use of distributed energy, intelligent technology, advanced power electronics technology to achieve efficient and close integration of centralized power supply and distributed power generation, and actively encourage the community to participate in the power market and jointly promote the development of the power grid. Microgrid has become an important component of Europe's future power grid due to its intelligence and diversified energy utilization. At present, the theory of operation, control, protection, safety and communication of microgrids has been initially formed in Europe, and these theories have been verified on the laboratory microgrid platform. Its follow-up tasks will focus on researching more advanced control strategies, developing appropriate standards, and establishing demonstration projects. That is, it is actively preparing for the large-scale access of distributed power and renewable energy and the initial transition of the traditional power grid to the smart grid.
1.3 Research on Japanese Microgrid
Based on the reality that domestic energy is increasingly scarce and the load is increasing, Japan has launched microgrid research, but its development goals are mainly aimed at diversifying energy supply, reducing pollution, and satisfying users' individualized power needs. Japanese scholars have also proposed flexible reliability and intelligent energy supply system (FRIENDS). The main idea is to add some flexible AC transmission system devices in the distribution network, and use the controller's fast and flexible control performance to achieve energy distribution to the distribution network. The structure is optimized and meets the various power quality requirements of the user. At present, Japan has adopted this system as one of the important implementation forms of its microgrid.
WHITE HOUSE HOLD CANDLES /VELAS/BOUGIES is the best product in Africa . White Fluted Candle packing way is 6pcs/bag 25bags/carton . Home Decoration White Candle packing way is normal , 8pcs/bag 65bags/carton . All the White Candle's Materails is Pure wax with stearic acid . as i know different country sell different size and package candle. For MAURITANIA ,SMALL CANDLES 19G 20G 22G 6X100BAG/CTN is best product . For Congo ,LARGER CANDLES 50G 53G 55G 6X50BAG/CTN POLYBAG sell very well .
FLUTED CANDLES 58G 65G 68G 6X25BAG/CTN POLYBAG PACKING TO ANGOLA ,NAMIBIA MOZAMBIQUE
6Pcs Packing White Candle,White Fluted Candle,Home Decoration White Candle,Pure Wax Fluted Candle
Shijiazhuang Zhongya Candle Co,. Ltd. , https://www.zycandlefactory.com