Biblio

This paper established a bi-level programming model for reactive power optimization, considering the feature of the grid voltage-reactive power control. The targets of upper-level and lower-level are minimization of grid loss and voltage deviation, respectively. According to the differences of two level, such as different variables, different solution space, primal-dual interior point algorithm is suggested to be used in upper-level, which takes continuous variables in account such as active power source and reactive power source. Upper-level model guaranteed the sufficient of the reactive power in power system. And then in lower-level the discrete variables such as taps are optimized by random forests algorithm (RFA), which regulate the voltage in a feasible range. Finally, a case study illustrated the speediness and robustness of this method.

In practical reflector antenna structures, components of the back-up structure (BUS) are selected form a standard steel library which is normally manufactured. In this case, the design problem of the antenna structure is a discrete optimization problem. In most cases, discrete design is solved by heuristic-based algorithm which will be computing-expensive when the number of deign variable increases. In this paper, a continuous method is used to transfer the discrete optimization problem to a continuous one and gradient-based technique is utilized to solve this problem. The method proposed can achieve a well antenna surface accuracy with all components selected from a standard cross-section list, which is shown by a 9m diameter antenna optimization problem.