Application of energy capacitor system to wind power generation

Abstract

In this paper, it is reported that energy capacitor system (ECS), which combines power electronic devices and electric double-layer capacitor, can significantly decrease voltage and power fluctuations of grid-connected fixed-speed wind generator. The proper selection of wind farm output power reference is still a problem for smoothing the wind farm output power. This paper proposes exponential moving average to generate the reference output power of a grid-connected wind farm. The objective of the control system is to follow the line power reference by absorbing or providing real power to or from the ECS. Moreover, the necessary reactive power can also be supplied to keep the wind farm terminal voltage at the desired reference level. Real wind speed data were used in the simulation analyses, which validate the effectiveness of the proposed control strategy. Simulation results clearly show that our proposed ECS can be suitable for wind power application.

Stability enhancement of wind power system by using energy capacitor system

“…In some reports, a battery energy storage system has proposed for smoothing wind power fluctuations. Another recent technology used in the power system applications is the energy capacitor system (ECS) [6] used as a power-smoothing tool. EDLC is suitable for smoothing the output power because it has some superior characteristics such EDLCs have short-charge/discharge times, no need protection circuit like batteries, fit and forget device, With its short charging and discharging times EDLCs are well suited for intermittent loads like wind park, long life (theoretically infinite), less weight, damage proof against short circuit completely.…”

“…This paper proposes a wind generation system composed of a variable speed wind turbine based PMSG and ECS. Some authors have proposed ECS in case of Fixed speed wind turbine based induction generator [6][7][8] where they used SMA (simple moving average), EMA (exponential moving average) to generate line power reference for comparing with the triangular wave to control the buck/boost converter for smoothing output power. SMA and EMA consist of a lot of delay circuit, adder, subtraction, summer and multiplier make the system bulky, complex, difficult to control.…”

Low power wind energy conversion system based on variable speed permanent magnet synchronous generators

“…At the present time, wind energy is gaining a great acceptance among all renewable energies [1]- [2], but not all places are capable of taking full advantage of it. Several statistical methods have been developed to calculate the average wind speed, the wind power density and its capacity factor for a specific geographical area [3]- [4].…”

Wind power and hydrogen generation system with cooperatively controlled three‐level NPC‐VSC based energy capacitor

“…In Reference [22], ECS is used for the smoothening of wind power, though the reference output power of the control system is not determined from realistic viewpoint and real wind speed data is not used throughout the analysis. In our previous study [23], we presented that two-level VSC based ECS can be a good tool to smooth the wind farm output power, though the capacity of the ECS used therein is not considered from the practical point of view. The aggregated wind park model is considered therein, which does not suites well for the analysis of wind farm output power fluctuation.…”

“…In Reference [24], though the aforementioned issues are incorporated including ECS capacity, wind park model, and hydrogen generator, an important issue has still not considered. Though two-level converter/inverter topology is frequently considered in ESS devices [5][6][9][10][11][12][22][23][24], multi-level converter/inverter topology is the suitable one used in ESS considering the factors of better harmonic performance and capability to withstand high phase currents [25].…”