Wind integration studies are important to estimate the effect which deployment of large amounts of variable and uncertain power generation will have on the grid. One of the most important aspects of reliable power system operations is the balance between power demand and generation. Different time frames require different techniques of balancing the generation and demand. Ramp events, which are sudden and large changes of power generation （it can be increasing or decreasing), are critical events. In this paper, we report the results of an analysis of wind power fluctuation and ramps from the measured power generation at existing wind farms located in Tohoku region of Japan. We also evaluate ramps of residual load (demand minus wind power generation).