tailieunhanh - Programmable Logic Controller plant through MMI Part 14

Tham khảo tài liệu 'programmable logic controller plant through mmi part 14', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 162 Programmable Logic Controller Additionally the common instability of electrical grids and the requirement for complete control over the quality of the electrical energy provision Papathanassiou Boulaxis 2005 Lund Munster 2003 set some serious obstacles in the dynamic exploitation of RES in autonomous electrical networks this leading to the introduction of an upper limit of instantaneous RES contribution equal to a pre-described percentage . 30 of the corresponding electricity demand. To confront the problem described several authors have every so often proposed alternative supply concepts such as water-pumping solutions hydrogen storage battery schemes and hybrid systems Kaldellis 2007 Kaiser 2007 . The system studied in this paper illustrated in Fig. 1 supports the prior exploitation of RES in collaboration with state of art internal combustion engines set to operate in the range of minimum specific fuel consumption maximum efficiency while the ESS adopted is used to meet the satisfaction of power quality issues. In case of energy surplus the excess amounts of energy are used to charge the ESS. When increased load demand and low RES production rates appear the energy content of ESS is used and if necessary the programmed control of the thermal power stations calls for the back-up engines to set on. Fig. 1. RES production system integrated with ESS units Energy Consumption Today the improvements in system communications have stimulated the implementation of distributed systems. These distributed systems are then usually managed by a centralized supervisory platform commonly known as a SCADA system Supervisory Control And Data Acquisition . This strategy reaches different fields from agriculture to industry building automation etc Figueiredo Botto 2005 Figueiredo Sá Costa 2007 . An optimal-performance supervisory system has the objective to allocate the minimal needed power generation to the traditional power plant in order to produce the electricity at a .