A Supercapacitor Remaining Energy Control Method for Smoothing a Fluctuating Renewable Energy Power

Lee, Wujong,Cha, Hanju The Korean Institute of Electrical Engineers 2015 Journal of Electrical Engineering & Technology Vol.10 No.1

This paper proposes a control method for maintaining the energy level for a supercapacitor energy storage system coupled with a wind generator to stabilize wind power output. Although wind power is green and clean energy source, disadvantage of the renewable energy output power is fluctuation. In order to mitigate the fluctuating output power, supercapacitor energy storage system (SCESS) and wind power simulator is developed. A remaining energy supercapacitor (RESC) control is introduced and analyzed to smooth for short-term fluctuating power and maintain the supercapacitor voltage within the designed operating range in the steady as well as transient state. When the average and fluctuating component of power increases instantaneously, the RESC compensates fluctuating power and the variation of fluctuating power is reduced 100% to 30% at 5kW power. Furthermore, supercapacitor voltage is maintained within the operating voltage range and near 50% of total energy. Feasibility of SCESS with RESC control is verified through simulation and experiment.

Power Fluctuation Reduction of Pitch-Regulated MW-Class PMSG based WTG System by Controlling Kinetic Energy

Howlader, Abdul Motin,Urasaki, Naomitsu,Yona, Atsushi,Senjyu, Tomonobu,Saber, Ahmed Yousuf Journal of International Conference on Electrical 2012 Journal of international Conference on Electrical Vol.1 No.2

Wind is an abundant source of natural energy which can be utilized to generate power. Wind velocity does not remain constant, and as a result the output power of wind turbine generators (WTGs) fluctuates. To reduce the fluctuation, different approaches are already being proposed, such as energy storage devices, electric double layer capacitors, flywheels, and so on. These methods are effective but require a significant extra cost to installation and maintenance. This paper proposes to reduce output power fluctuation by controlling kinetic energy of a WTG system. A MW-class pitch-regulated permanent magnet synchronous generator (PMSG) is introduced to apply a power fluctuation reducing method. The major advantage of this proposed method is that, an additional energy storage system is not required to control the power fluctuation. Additionally, the proposed method can mitigate shaft stress of a WTG system. Which is reflected in an enhanced reliability of the wind turbine. Moreover, the proposed method can be changed to the maximum power point tracking (MPPT) control method by adjusting an averaging time. The proposed power smoothing control is compared with the MPPT control method and verified by using the MATLAB SIMULINK environment.

A Supercapacitor Remaining Energy Control Method for Smoothing a Fluctuating Renewable Energy Power

Wujong Lee,Hanju Cha 대한전기학회 2015 Journal of Electrical Engineering & Technology Vol.10 No.1

This paper proposes a control method for maintaining the energy level for a supercapacitor energy storage system coupled with a wind generator to stabilize wind power output. Although wind power is green and clean energy source, disadvantage of the renewable energy output power is fluctuation. In order to mitigate the fluctuating output power, supercapacitor energy storage system (SCESS) and wind power simulator is developed. A remaining energy supercapacitor (RESC) control is introduced and analyzed to smooth for short-term fluctuating power and maintain the supercapacitor voltage within the designed operating range in the steady as well as transient state. When the average and fluctuating component of power increases instantaneously, the RESC compensates fluctuating power and the variation of fluctuating power is reduced 100% to 30% at 5kW power. Furthermore, supercapacitor voltage is maintained within the operating voltage range and near 50% of total energy. Feasibility of SCESS with RESC control is verified through simulation and experiment.

전기추진선박의 제어전원 및 보조장치 전원공급용 인버터의 입력전압변동 시험평가 및 분석

송왕근,최용훈 대한전기학회 2020 전기학회논문지 Vol.69 No.8

The main power supply of electric vehicles and ships is generally composed of a battery, a generator and a fuel cell, and a propulsion motor and inverter are used as a driving device. In addition to the main power supply for electric power-driven driving, additional auxiliary power supply for control system and auxiliary system is required, and power conversion devices (inverters and converters) are used for this purpose. Power conversion devices for auxiliary power supply receives power from main power supply such as battery, generator and fuel cell and performs the AC or DC power conversion. The voltage variation of main power supply depends on the usage conditions of electric propulsion system. The power conversion devices for auxiliary power supply shall not cause output stop even if the voltage of main power supply suddenly changes to the allowable voltage range. The output of the power conversion devices for auxiliary power supply shall have an operating capability to produce a stable output within the permitted voltage range. This paper deals with the test evaluation and analysis for the input voltage fluctuation of the DC/AC inverter(power conversion devices) in auxiliary power supply of electric ship..

전기추진선박의 제어전원 및 보조장치 전원공급용 DC/AC 인버터의 입력전압변동 시험평가 및 분석

송왕근(Wang-Keun Song),최용훈(Yong-Hoon Choi) 대한전기학회 2020 전기학회논문지 Vol.69 No.8

The main power supply of electric vehicles and ships is generally composed of a battery, a generator and a fuel cell, and a propulsion motor and inverter are used as a driving device. In addition to the main power supply for electric power-driven driving, additional auxiliary power supply for control system and auxiliary system is required, and power conversion devices (inverters and converters) are used for this purpose. Power conversion devices for auxiliary power supply receives power from main power supply such as battery, generator and fuel cell and performs the AC or DC power conversion. The voltage variation of main power supply depends on the usage conditions of electric propulsion system. The power conversion devices for auxiliary power supply shall not cause output stop even if the voltage of main power supply suddenly changes to the allowable voltage range. The output of the power conversion devices for auxiliary power supply shall have an operating capability to produce a stable output within the permitted voltage range. This paper deals with the test evaluation and analysis for the input voltage fluctuation of the DC/AC inverter(power conversion devices) in auxiliary power supply of electric ship..

간헐성과 변동성을 가진 풍력출력 변동 완화를 위한 제어기 알고리즘 성능과 배터리 용량 분석

김진태(Jin-Tae Kim),이승용(Seung-Yong Lee),석복렬(Bok-Yeol Seok) 대한전기학회 2021 전기학회논문지 P Vol.70 No.2

With the significant renewable energy penetration, the power output fluctuation could result in the power quality problems. Especially, to improve the power grid’s stability, it is considerable concern that the intermittent and variable power output of renewable energy plants needs the large-scale Energy Storage System(ESS). In this study, the Moving Average(MA) filter and the First-order Low Pass Filter(LPF) are investigated for less output power fluctuation and smaller battery energy capacity, based on the smoothness of each mitigated wind power output and the corresponding energy profile during charge/discharge operations. Moreover, the effect of the Ramp Rate(RR) on the battery energy capacity is analyzed varying with the smoothing filter, to reduce the rate of change of the smoothed wind power fluctuation. MA filter has the similar power smoothing performance as that of LPF with much less battery energy capacity. Moreover, the consecutive MA filter and RR control require less battery energy capacity than consecutive LPF and RR control. Also, the battery capacity for mitigation of the intermittent wind power output fluctuation depends on the constraint rate and the filter type. However, the filter type has little influence on the battery capacity to mitigate the variable wind power output fluctuation at a constraint rate more than 20%.

A Novel Direct Power Control Strategy of Three-level NPC Rectifier without Abnormal Instantaneous Reactive Power Fluctuation

LI Ning,HUANG Jingjing,ZHANG Hui,WANG Yue,WANG Zhao’an 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

A novel switching table of direct power control (DPC) strategy for three-level NPC rectifier is proposed in this paper. With the theory of instantaneous power, it gets the inner relationship between instantaneous power (active power and reactive power) and space voltage vectors. The dc-link voltages are maintained at the required level using hysteresis controller for the NP current exploiting the redundancy states of the rectifier. With the switching table proposed in this paper, the excellent dynamic and transient performances are achieved under unity power factor operation without abnormal instantaneous reactive power fluctuation. Simulation results verify the validity and feasibility of the proposed strategies.

A Supercapacitor Remaining Energy Control Method for Smoothing a Fluctuating Renewable Energy Power

이우종,차한주 대한전기학회 2015 Journal of Electrical Engineering & Technology Vol.10 No.1

This paper proposes a control method for maintaining the energy level for asupercapacitor energy storage system coupled with a wind generator to stabilize wind power output. Although wind power is green and clean energy source, disadvantage of the renewable energy outputpower is fluctuation. In order to mitigate the fluctuating output power, supercapacitor energy storagesystem (SCESS) and wind power simulator is developed. A remaining energy supercapacitor (RESC)control is introduced and analyzed to smooth for short-term fluctuating power and maintain thesupercapacitor voltage within the designed operating range in the steady as well as transient state. When the average and fluctuating component of power increases instantaneously, the RESCcompensates fluctuating power and the variation of fluctuating power is reduced 100% to 30% at 5kWpower. Furthermore, supercapacitor voltage is maintained within the operating voltage range and near50% of total energy. Feasibility of SCESS with RESC control is verified through simulation andexperiment.

Grid Voltage Modulated Direct Power Control for Output Smoothing in Battery Energy Storage Systems

Yeon Joo Hong,Yong Woo Jeong,Chung Choo Chung 제어로봇시스템학회 2020 제어로봇시스템학회 국제학술대회 논문집 Vol.2020 No.10

This paper proposes a sliding mode control (SMC) method for the grid voltage modulated direct power control(GVM-DPC) of Energy Storage Systems and Power Conversion System (ESS/PCS), which can control the instantaneous active power and reactive power directly. Wind power (WP) can cause serious stability problems in the power system because of its high variability depending on wind speed. To solve this problem, many power generation companies or grid operators have begun to use ESS. The conventional control method needs to use Phase-Locked-Loop (PLL), which extracts a phase angle of the grid required for the controller because it is modeling in d - q frame. This PLL performance affects the transient performance of ESS/PCS systems. We show the proposed SMC for the GVM-DPC algorithm enhances the tracking performance of the output power. We validate the proposed SMC for the GVM-DPC algorithm with MATLAB/Simulink and OPAL-RT (real-time simulator) environment systems. It turns out that the proposed method shows improved tracking performance over other conventional controllers.

Optimal Power Control Strategy for Wind Farm with Energy Storage System

Cong-Long Nguyen,Hong-Hee Lee 대한전기학회 2017 Journal of Electrical Engineering & Technology Vol.12 No.2

The use of energy storage systems (ESSs) has become a feasible solution to solve the wind power intermittency issue. However, the use of ESSs increases the system cost significantly. In this paper, an optimal power flow control scheme to minimize the ESS capacity is proposed by using the zero-phase delay low-pass filter which can eliminate the phase delay between the dispatch power and the wind power. In addition, the filter time constant is optimized at the beginning of each dispatching interval to ensure the fluctuation mitigation requirement imposed by the grid code with a minimal ESS capacity. And also, a short-term power dispatch control algorithm is developed suitable for the proposed power dispatch based on the zero-phase delay low-pass filter with the predetermined ESS capacity. In order to verify the effectiveness of the proposed power management approach, case studies are carried out by using a 3-MW wind turbine with real wind speed data measured on Jeju Island.