ANALYSIS METHOD FOR HUNTING PHENOMENON OF FREQUENCY FEEDBACK SYSTEM, AND AVOIDANCE METHOD

摘要

PROBLEM TO BE SOLVED: To analyze a hunting phenomenon by clarifying a mechanism that a power conditioner for photovoltaic power generation causes the hunting phenomenon.SOLUTION: An open loop transfer function for present state analysis based on a transfer function of a frequency feedback system and a transfer function of a power system to which a power conditioner is connected is calculated based on a variable (s) by an analysis device, and a Nyquist locus is drawn in a graph. The transfer function of the frequency feedback system is represented by a product of a waste time element 21 indicating a waste time (τ), a high-pass filter element 22, a low-pass filter element 23 and a gain element 24. The transfer function of the power system is represented by temporal differentiation of a phase change for a synthetic active power characteristic index based on active power characteristic indices of a load and the power conditioner, line impedance and a frequency deviation caused by reactive power outputted from the power conditioner. A transfer function for hunting measures is represented based on a product of the open loop transfer function and a primary delay element.SELECTED DRAWING: Figure 3