Providing Frequency Support of Hydro-Pumped Storage to Taiwan Power System with Wind Power Integration

The combination of wind and pumped storage is a useful method to compensate the fluctuation of wind power generation, which would exploit the abundant wind potential and increase wind power penetration. Taiwan Power Company (TPC) develops renewable energy actively in recent years. Moreover, TPC has started planning a high penetration wind power system and building offshore wind farms around the coast of Zhangbin, Yunlin and Penghu. The target of the offshore wind power installed capacity is up to 3 GW by 2025. However, the integration of the large scale of wind power would give huge challenges to the system operator because wind is randomly characterized. In this study, after high penetration wind power is integrated, the impacts of system frequency and the dispatch of conventional units will be discussed. Additionally, the hybrid system combing wind power with pumped-storage will be planning to reduce the effect of system frequency.

A review of Danish integrated multi-energy system flexibility options for high wind power penetration

The current status of wind power and the energy infrastructure in Denmark is reviewed in this paper.The reasons for why Denmark is a world leader in wind power are outlined.The Danish government is aiming to achieve 100%renewable energy generation by 2050.A major challenge is balancing load and generation.In addition,the current and future solutions of enhancing wind power penetration through optimal use of cross-energy sector flexibility,so-called indirect electric energy storage options,are investigated.A conclusion is drawn with a summary of experiences and lessons learned in Denmark related to wind power development.

Stochastic Dynamic Economic Dispatch of Wind-integrated Electricity and Natural Gas Systems Considering Security Risk Constraints

As the proportion of wind power generation increases in power systems,it is necessary to develop new ways for wind power accommodation and improve the existing power dispatch model.The power-to-gas technology,which offers a new approach to accommodate surplus wind power,is an excellent way to solve the former.Hence,this paper proposes to involve power-to-gas technology in the integrated electricity and natural gas systems(IEGSs).To solve the latter,on one hand,a new indicator,the scale factor of wind power integration,is introduced into the wind power stochastic model to better describe the uncertainty of grid-connected wind power;on the other hand,for quantizing and minimizing the impact of the uncertainties of wind power and system loads on system security,security risk constraints are established for the IEGS by the conditional value-at-risk method.By considering these two aspects,an MILP formulation of a security-risk based stochastic dynamic economic dispatch model for an IEGS is established,and GUROBI obtained from GAMS is used for the solution.Case studies are conducted on an IEGS consisting of a modified IEEE 39-bus system and the Belgium 20-node natural gas system to examine the effectiveness of the proposed dispatch model.

Innovated Inertia Control of DFIG with Dynamic Rotor Speed Recovery

High wind power penetration(WPP)is challenging system frequency stability.As a countermeasure,virtual inertia controls are introduced,utilizing kinetic energy(KE)stored in wind turbine generators(WTGs)for frequency regulation.Without restoration,generation efficiency of WTGs will be degraded after inertia contribution.To counter this issue,we propose an inertia control scheme of a doubly fed induction generator(DFIG),aiming at achieving dynamic inertia recovery regarding both KE and DC link energy.An asymmetrical droop control,referred to as the rate of change of frequency(RoCoF),is proposed for KE management.The upper boundary of droop gain is extended to give full play to converters and is revised,considering the system frequency state,to counter positive feedback issues induced by reversible gain regulation,which is restricted by KE to ensure stable operations as well.The inertial DC energy needed to cooperate with KE control regarding countering small fluctuations,is improved with an orderly recovery behavior.Case studies are conducted under dynamic wind conditions and the results indicate that with our proposed scheme,the ability of dynamic inertia recovery can be obtained,bringing DFIG higher generation efficiency and more adequate operation margin for sustained regulation.Essentially,the inertial frequency response and fluctuation suppression ability is well maintained.