Kotaro Hashikura

An internal state decomposition approach to a discrete-time H2 control problem with irrational input non-minimum phase property

Abstract An internal state decomposition approach to a class of discrete-time H 2 control problems with irrational non-minimum phase property at the control input is proposed. This is a generalization of the state-variable transformation to derive the discrete-time Smith predictor for a single input-delay system. The H 2 optimal controller is derived using the orthogonality principle in H 2 space as a direct consequence of the state decomposition. The characterization of the optimal cost by the previous and alternative truncation operators is also discussed.

Design of a periodic photovoltaic charge-discharge schedule reflecting power demand prediction error

Charging and discharging of photovoltaic battery are scheduled based on the future prediction of power demand and photovoltaic generation capability. The prediction errors lead to the infeasibility of the schedule, and detailed analysis of them is required for practical operation. This paper considers a long-run scheduling problem based on the periodic demand prediction, and proposes a design method of battery charge-discharge schedule utilizing a reference governor approach. The proposed design enables to recover the periodic schedule while canceling the power demand prediction error.

Reduced-order Construction of H∞ State Feedback Law for Discrete-time Single Input-delayed Systems

Abstract KYP equations for discrete time-delay systems involve computational difficulty. This paper addresses efficient construction of the H ∞ state feedback law for discrete-time single input-delayed systems. The min-max optimization is adopted to construct the stabilizing solution of the KYP equation for the input-delayed case from that for the delay-free case. The consistency with the previous results based on the J -spectral factorization theory is also discussed.

On battery charge-level scheduling considering line temperature constraints

Under the large-scale penetration of photovoltaic generation systems, the temperature constraints of transmission lines play a key role in the flexible operation of the power grid. In this paper, simplified line temperature constraints are derived from its physical model, and the strength and limitation of the simplified models are investigated. The features of the proposed models are further discussed based on the simulations of economic load dispatching control (EDC) and EDC recovering.

An explicit design method of robust periodic MPC with application to charge-level control of photovoltaic battery

A robust periodic MPC design method is proposed in view of application to photovoltaic battery charge/discharge operation. The battery operation is formulated as the problem of recovering the battery charge to a desired periodic reference while maintaining the proper operating ranges. We achieve the periodic constraint satisfaction under the prediction error by extending the time-invariant constraint tightening technique. The proposed design method enables us to complete the computation of the control law before beginning the battery operation. In the numerical simulation, we utilize that advantage to assess the relationship between the spinning reserve and recoverable battery charge levels.