tailieunhanh - Governing Fundamentals and Power Management phần 6

Này được gọi là "phi tuyến tính liên kết" liên kết phi tuyến tính cũng được yêu cầu trên một số hệ thống bơm diesel, mặc dù những điều kiện này thường không nghiêm trọng như khi kiểm soát một van bướm bộ chế hòa khí. Trong tất cả các trường hợp liên kết được thiết kế để cung cấp sản lượng động cơ tăng tỷ lệ thuận với sự chuyển động của đầu ra thống đốc. | Manual 26260 Governing Fundamentals and Power Management Assuming ộ continues to rotate at a constant rate and that the circuit-breaker time delay Tb the synchronizer window ộw and selected synchronizer window dwell time Twd are known the worst case value which the synchronizer will allow ộs can be predicted. ộs is equal to ộ at the time the synchronizer issues the breaker closure command ộw in the worst case plus the change in ộ due to the rate of change in ộ times the breaker delay Tb in the worst case . Therefore ộ ộwc when ộ at the instant the breaker closure command is issued ộw. The rate of change of ộ ộ s is the total degrees in the window divided by the dwell time of the window or 2õw. Twd 2 Gw then Gwc Gs Tb Twd For Example Assume a synchronizer configured for a window of 10 degrees and a window dwell time of 1 2 second. Assume the breaker is never slower than 13 cycles. If 0w 10 Twd s Tb _ _13 cycles 0 217 s 60 cycles second . then wc Gs 1O 2 0 sec. sec. wc In comparison a window of 5 and a window dwell time of 1 second using the same breaker. _ _5O 2 5 sec. Gwc Gs 5 1 sec. Gwo BUS GENERATOR Figure 7-9. Phase Angle Relationship Woodward 45 Governing Fundamentals and Power Management Manual 26260 Chapter 8. Managing Power for the Desired Result Peaking or Peak Load Control Peak sharing peaking or peak load control all refer to methods used to limit the peak electrical demand purchased from a utility. Electrical rates usually are determined by the peak demand on the utility during a given time period. Sometimes a peak demand lasting as brief as fifteen minutes out of a 30-day period will determine the charge leveled for all power purchased during those 30 days. How Is Peak Sharing Peaking or Peak Load Control Accomplished Normally peak load control is accomplished by one of four methods Plant load control or load shedding which means the shutting off of optional loads to hold peak consumption below a maximum desired load .