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In this work we had presented a power system electricity frequency control approach of 100% renewable energy sources isolated power grid by applying model predictive control (MPC). As the PV panel and storage battery price had dramatically dropped in these years, large capacity of PV generation and storage battery had been introduced base on an original 100% renewable energy power system. MPCs had been design for each of the model (Photovoltaic Generation, Wind turbine Generation, Storage Battery, Fuel Cell and Seawater Electrolyzer) to suppress the consumption and generation balance. In addition, in order to suppress the load frequency, demand response (real-time pricing) also had been applied in this scheme by adjust the controllable loads. All of the control approach proposed in this work had been verified by Matlab@/Simulink@. And by discuss and analysis the simulation results, the stability, robustness, reliability and effectiveness of this scheme had been examined.

The rapid growth of renewable energies specifically wind and solar with their intermittent phenomena has recently become an exciting and important topic among researchers worldwide. The integration of such devices in distribution networks comprising of battery energy storage systems (BESSs) is considered as efficient and complementation approach which their well-managed configuration and scheduling via optimal arrangement yield not only productive and reliable power delivery to end-users, but cost-saving opportunity for utility managers. When dealing with photovoltaic (PV), reactive power capability of PV inverter is another aspect of interest that can contribute in enhancing effective penetration of wind, solar, and storage system into distribution networks. In this paper, a robust and novel optimization technique epsilon multiobjective genetic algorithm $\epsilon$-MOGA is proposed and applied to a real 162-bus distribution network. A three-objective function optimization encompassing environmental, technical, and economic aspect is developed to size the centralized wind-farm and BESS parameters, distributed rooftop PV, and PV inverter reactive power control in an optimal manner. The proposed arrangement is simulated in MATLAB and compared with several cases to show its superior implementation concerning carbon emission reduction, better technical aspect, annual saving, and grid power alleviation.

This paper presents a power smoothing control scheme for a permanent-magnet-synchronous-generator-based wind farm considering wake effects. The integrated power smoothing method consists of a pitch angle control system, a kinetic wind-energy turbine inertia control system, and a dc-link voltage control system. Low frequency range power fluctuations caused by wind speed variations are smoothed by the pitch angle control system and the kinetic wind-energy turbine inertia control system. Power fluctuations in the high frequency range are smoothed by the dc-link voltage control system. This power smoothing approach is cost-effective because the power smoothing is made possible without additional energy storage devices. In addition, the wake effects of the wind farm are considered for power smoothing with different tower spaces. The proposed method is compared with the conventional maximum-power-point-tracking method. Simulation results confirm the proposed method efficacy in smoothing the power injected by a wind farm.

In consideration of the natural environment and depletion of energy resources, the widespread use of electric power system is expected in which the power is generated from sources of renewables such as wind and solar. When these plants are introduced in large scale, the use of broad land is required. Due to low transmission losses and small stability problems, multi-terminal high voltage direct current (MTDC) transmission becomes advantageous as long-distance power transmission system. Since DC current does not incorporate a zero cross point, therefore it’s blocking is difficult. This paper proposes a DC resonant semiconductor breaker which enables rapid fault clearance for self-excited HVDC transmission. This circuit breaker is connected as a semiconductor switch, in parallel with a group of capacitors, and resistors in the DC transmission line. The capacitor is charged to a higher voltage from the DC transmission line. For generating reverse current to allow the zero cross point in the transmission line, the semiconductor switch turns on to open the circuit breaker. After blocking, the inductance of the line is demagnetized by the resistor and fault clearing is achieved. The system except fault point can continue its normal operation.

AbstractThis paper deals with controlling the output power smoothing of a wind energy conversion systems (WECS) by using permanent magnet synchronous generator (PMSG). It uses the inertia control of the wind turbine and DC-link voltage control. The PMSG is connected to the grid through a generator-side converter and a grid-side inverter based on AC-DC-AC methods. The generator-side converter is used to control the torque of the PMSG while the grid-side inverter is used to control DC-Link voltage and grid voltage. Fuzzy logic is implemented to determine the torque command by using inertia of wind turbine. The inputs of the fuzzy logic are given by the operating point of the rotational speed of the PMSG and the difference between the wind turbine torque and the generator torque. From the proposed method, the generator torque is smoothed and kinetic energy generated by the inertia of the wind turbine is used to smooth the power fluctuations of PMSG. Also, a stable operation of WECS is achieved during the system fault by using the chopper circuit in the DC-link circuit. The output power smoothing is achieved with stability and low cost. The effectiveness of the proposed method is verified by the numerical simulations.

A pulse amplitude modulation (PAM) control can adjust the DC-link voltage of a motor drive. A bi-directional buck-boost DC-DC converter is required at the primary side of PWM-VSI to implement PAM control. This paper is proposed PAM control technique for a permanent magnet synchronous motor (PMSM) based on fuzzy control system. The PAM coefficient (K_PAM) is a constant value for a conventional PAM control system. It requires online adjustment to improve overall performance of a PAM control system. The proposed fuzzy controller based PAM control regulates the K_PAM according to online commanded load voltage. This paper deals with different operation modes of a bi-directional buck-boost DC-DC cascade converter, motoring (accelerate and steady state) and braking operations of a PMSM at different load conditions and speeds. The total harmonic distortion (THD) and system efficiency are also shown in this paper. Effectiveness of the proposed method is confirmed by simulation results.

This paper presents a high efficiency drive strategy for micro-turbine generator (MTG) in which permanent magnet synchronous generator (PMSG) is used. PMSG operates at maximum efficiency point by optimizing the phase of armature current of PMSG; i.e., an optimum d-axis current in the rotor reference frame is analytically derived from mathematical model of PMSG taking iron loss into account. In addition, in order to use turbine output power effectively, compressor input power is minimized by optimizing revolving speed of PMSG. Simulation results confirm validity of the proposed method.

This paper presents a high efficiency drive strategy for micro-turbine generator (MTG) in which permanent magnet synchronous generator (PMSG) is used. PMSG operates at maximum efficiency point by optimizing the phase of armature current of PMSG; i.e., an optimum d-axis current in the rotor reference frame is analytically derived from mathematical model of PMSG taking iron loss into account. In addition, in order to use turbine output power effectively, compressor input power is minimized by optimizing revolving speed of PMSG. Simulation results confirm validity of the proposed method.

Nowadays a sensor-less vector control system for a motor drive becomes promising to avoid a position sensor. A back electro-motive-force or flux observer is used for sensor-less drive of permanent magnet synchronous motors from middle to high speed range. Thus, the estimation accuracy of the observer influences sensor-less drive performance. This paper proposes a sensor-less vector control system using the H? flux observer in which the observer gain is designed based on the H? control theory. This observer is insensitive to high frequency disturbances such as voltage disturbance due to non-linearity of PWM voltage source inverter, measurement noise of current sensors, and modeling errors. So, the total performance of a sensor-less control system is enhanced. The detailed configuration of the H? flux observer is described in this paper. Simulation results are compared with the conventional full-order flux observer-based sensor-less system.

Nowadays a sensor-less vector control system for a motor drive becomes promising to avoid a position sensor. A back electro-motive-force or flux observer is used for sensor-less drive of permanent magnet synchronous motors from middle to high speed range. Thus, the estimation accuracy of the observer influences sensor-less drive performance. This paper proposes a sensor-less vector control system using the H? flux observer in which the observer gain is designed based on the H? control theory. This observer is insensitive to high frequency disturbances such as voltage disturbance due to non-linearity of PWM voltage source inverter, measurement noise of current sensors, and modeling errors. So, the total performance of a sensor-less control system is enhanced. The detailed configuration of the H? flux observer is described in this paper. Simulation results are compared with the conventional full-order flux observer-based sensor-less system.

Wind energy conversion systems have become important in the research of renewable energy sources. This is in no small part due to the rapid advances in the size of wind generators as well as the development of power electronics and their applicability in wind energy extraction. However, wind energy has a drawback of having only 1/800 (gm per cubic cm) density as compared to that of water energy. Wind energy does not remain constant and wind turbine output is proportional to the cube of wind speed, which causes the generated power of the wind turbine generator (WTG) to fluctuate. In this paper, a technique is proposed for output power leveling of a wind generation system. Wind turbine blades have a large inertia compared to the inertia of a generator. The inertia of the rotor behaves like an inductor in an electrical circuit. It helps smooth the wind turbine output power, stores energy during acceleration, and restores energy during deceleration. The effectiveness of output power leveling control is verified by simulations for the wind power generation system.

Wind energy conversion systems have become important in the research of renewable energy sources. This is in no small part due to the rapid advances in the size of wind generators as well as the development of power electronics and their applicability in wind energy extraction. However, wind energy has a drawback of having only 1/800 (gm per cubic cm) density as compared to that of water energy. Wind energy does not remain constant and wind turbine output is proportional to the cube of wind speed, which causes the generated power of the wind turbine generator (WTG) to fluctuate. In this paper, a technique is proposed for output power leveling of a wind generation system. Wind turbine blades have a large inertia compared to the inertia of a generator. The inertia of the rotor behaves like an inductor in an electrical circuit. It helps smooth the wind turbine output power, stores energy during acceleration, and restores energy during deceleration. The effectiveness of output power leveling control is verified by simulations for the wind power generation system.