Các bản vẽ kỹ thuật để chế tạo là sản phẩm cuối cùng của khâu thiết kế. Chúng phải thỏa mãn hai mục đích: bao gồm đầy đủ tất cả các thông tin cần thiết để chế tạo và cũng còn là một tiêu chí kiểm soát kỹ thuật đối với các mức độ sửa chữa. Trước cuối thế kỷ 20, rất nhiều bản vẽ kỹ thuật được thực hiện bằng tay với sự trợ giúp của bảng vẽ cơ khí. Sự ra đời của máy tính với giao diện người dùng đồ họa đã có thể giúp thực hiện. | Wind Farms and Grid Codes 19 Portugal - REN Portaria n. 596 2010 de 30 de Julho Canada - AESO Wind Power Facility - Technical Requirements Revision 0 November 15 2004. Australia - AEMC National Electricity Rules NER Version 39 16 September 2010 Ireland - EIRGRID WFPS1- Controllable Wind Farm Power Station Grid Code Provisions EirGrid Grid Code Version October 16th 2009. Fault ride through requirements are described by a voltage vs. time characteristic denoting the minimum required immunity of the wind power station. The fault ride through requirements also include fast active and reactive power restoration to the prefault values after the system voltage returns to normal operation levels. Some codes impose increased reactive power generation by the wind turbines during the disturbance in order to provide voltage support a requirement that resembles the behaviour of conventional synchronous generators in over-excited operation. Fig. 1 presents in the same graph the fault ride through requirements from the different Grid Codes. These requirements depend on the specific characteristics of each power system and the protection employed and they deviate significantly from each other. Fig. 1. Fault ride through requirements. 3. Wind turbine fault-ride through As it has been said one of the main problems for power quality are voltage dips. Due to high renewable penetration level in transmission system Transmission System Operators TSO demand to this sort of energy source support voltage under voltage sags. This obligation has provoked a huge investment in devices to support wind systems during voltage dips. Fig. 2 shows the three main technologies in the wind turbine industry. Their behaviour is different in continuous operation and during voltage dips. Fig. 2a shows the fixed-speed wind turbine with asynchronous squirrel cage induction generator SCIG directly connected to the grid via transformer. Fig. 2b represents the 20 From Turbine to Wind Farms - Technical .
