ABSTRACT
For example, Figure VI.2.4 shows the change of the system frequency in two different operating conditions following the disconnection of three wind parks producing approximately 30 MW. First, the system is considered to operate with 28% wind power, equal to 46 MW, and with the fast thermal units such as the diesel machines and gas turbines to provide the spinning reserve (fast spinning reserve). The lower value of the frequency is 49.31 Hz. Second, the system is again considered to operate with the same high penetration ofwind power but with the slower machines, such as the steam turbines, to cover the main spinning reserve plus some diesel machines (slow spinning reserve). In this case, the lower frequency value, close to 49 Hz, could cause the operation of the protection devices of the rest of the wind parks. The total wind power disconnection would lead the system to collapse.
