Tham khảo tài liệu 'from turbine to wind farms technical requirements and spin-off products part 5', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Active and Reactive Power Formulations for Grid Code Requirements Verification 49 Active power requirements The . and the draft of the . establish no active power consumptions are allowed during the fault and the voltage recovery period. However some momentary active power consumptions are allowed by both Operation Procedures during the fault and the clearance period such as figs. 5 and 6 respectively show. Fig. 5. Active power requirements according to the . a Balanced voltage dips b unbalanced voltage dips Fig. 6. Active power requirements according to the . a Balanced voltage dips b unbalanced voltage dips 50 From Turbine to Wind Farms - Technical Requirements and Spin-Off Products Active power consumptions lower than 10 of installation registered rated power are admitted during the maintenance of the fault in presence of three-phase balanced voltage dips while this maximum allowed magnitude is increased up to 45 of registered rated power for unbalanced voltage dips but only during 100 ms 30 each 20 ms cycle . These active power consumptions referred by the . are implicitly defined by 20 . The . does not express which active power formulation must be used. German Grid Code is not as exhaustive as the Spanish Grid Code and it specifies wind farms have the ability of active power curtailment with a ramp rate 10 of grid connection per minute. Current requirements Spanish and German Grid Codes require the installation supplies the maximum possible current during the fault maintenance and the voltage recovery period. This current delivery must verify that reactive current is above the minimum unitary values delimited by the lines in for each grid code. Fig. 7. Minimum admissible values of the reactive current a . b . c Netz Active current limits in per unit values according to the . are mathematically expressed in function of the unitary voltage values V as Ia yf 1 - 1 2 57- V
