Tham khảo tài liệu 'wind power 2011 part 3', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | An Analytical Analysis of a Wind Power Generation System Including Synchronous Generator with Permanent Magnets Active Rectifier and Voltage Source Inverter 47 kL q 0 a Fig. 20. From it is clear that the larger value of voltage w corresponds to the lower value of . current iGo while iGq01 iGqo2 that follows from 5a . . . -r. Ị iGqo1 iGqo2 URdo Xqi PRol . _ _ .1 q 1 qf lGdo1 2 1 4 I I I I . ỏy 2 V 2 JI Ú J At the point when the power is maximum for a given frequency of rotation PRo PRomax the relation 34 the orthogonal components of currents and voltages are determined by the relations 31 37 . The full value of the generator current is 2 2 1 - lG 01 2 pq 1 1 - kL 2 PRo a 1 q 2PLpRq a 1 q 1 q 48 Wind Power Graphs of the dependences uRq0 i Go and uGo from are presented in . In these graphs to the right of points a b c d there is a limitation of the depth of modulation and the proposed model becomes inadequate to the real modes. The first mode on the graphs of is characterized by the fact that the generator voltage does not change significantly with variation of a . From it follows that in mode 1 the system has a positive internal differential resistance and therefore may be potentially unstable at some disturbing effects. kL q a Fig. 21. b c d An Analytical Analysis of a Wind Power Generation System Including Synchronous Generator with Permanent Magnets Active Rectifier and Voltage Source Inverter 49 It should be noted that the mode when the phases of voltage and current of the fundamental harmonics are the same essentially involves a change of uGo and i Go under the change of frequency of rotation of the shaft of WT a . The equation 28 can be rewritten in the co-ordinates of orthogonal components of a control input wave M d Mq Md 2 r I2 1 O -1 Yuj 1 q 3 r O 1 Mq 3 q - 1 2 O Ifr q 2 1 38 Expression 38 defines a parametric relationship between the orthogonal components which ensures the phase coincidence of the main .