Unreliability Tracing of Power Systems with High Penetration of Wind Power Based on Temporal Decomposition Model

An unreliability tracing model for power systems assigns responsibility for unreliability to each component by quantifying its impact on the power system’s reliability. This paper extends the concept of unreliability tracing to power systems with high penetration of wind power, to realize unified allocation of load shedding to conventional generating units and wind power. First, a quantitative evaluation model for load shedding is established, which considers unreliable factors, such as failures of components, fluctuation, and intermittence of wind power. Then, load shedding at a certain time is decomposed into the part due to remaining unreliable factors that happened before the last time and the part due to unreliable factors that happened between the last time and the certain time, by decomposing the load shedding formula. Next, for parameters of the second part of the load shedding formula, unreliable factors that caused the value of these parameters to be located in regions leading to load shedding are decomposed into two parts in time sequence. The second part of load shedding is also decomposed into two parts corresponding to the decomposed unreliable factors. According to the decomposition of unreliable factors, two criteria for judging whether the component is responsible are extracted. Finally, the last two parts of load shedding are allocated to each component based on assumed baseline values of these criteria for each component, and the first part of load shedding is allocated, recursively. Several systems, including a modified provincial power system, are used to validate the rationality and validity of the model.