New architecture and SCADA for stand‐alone hybrid (medium‐sized asynchronous wind turbine + UPS with battery + photovoltaic array) power system without diesel generator

Wind Energy ◽  
2019 ◽  
Author(s):  
Ki Yong Choe ◽  
Ho Kim ◽  
Jong U Li ◽  
Chung Il Hyon ◽  
Il Yong Kang
2018 ◽  
Vol 42 (5) ◽  
pp. 411-435 ◽  
Author(s):  
Sergey N Udalov ◽  
Andrey A Achitaev ◽  
Alexander G Pristup ◽  
Boris M Bochenkov ◽  
Yuri Pankratz ◽  
...  

The paper is devoted to investigations of dynamic processes in a local power system consisting of wind turbines with a magnetic continuously variable transmission. Due to low inertia of wind turbine generator rotors, there is a problem of ensuring dynamic stability at sharp load changes or at short circuits in an autonomous power system. To increase dynamic stability of the system, two algorithms for controlling a magnetic continuously variable transmission are presented. The first algorithm stabilizes a rotation speed of the high-speed rotor of a magnetic continuously variable transmission from the generator side in a local power system consisting of wind turbines with uniform synchronous generators with permanent magnets having equal moments of inertia. Undoubtedly, local power systems having only the wind turbines with equal mechanical inertia time constants are not widely used due to stochastic nature of wind energy. Therefore, wind power systems are combined with a diesel generator or a gas-turbine unit. Investigations show that the use of the only speed stabilization algorithm is not enough for such power systems, because there is a possibility for occurrence of asynchronous operation under specific power changes due to the difference in moments of inertia of generator rotors. Thus, the second algorithm uses the phase shift compensation in accordance with a primary generator in an autonomous power system consisting of non-uniform generators having different mechanical inertia time constants. As a primary generator, a diesel generator or a gas-turbine unit having a primary speed controller may be used. It should be noted that algorithms of stabilization for speed and phase angle are extended by an inertial circuit of aerodynamic compensation for torque of rotation from the wind turbine side to reduce loading on an energy storage unit of the magnetic continuously variable transmission at disturbances from the generator side and the turbine side.


Author(s):  
Mohd Azman Rosli ◽  
Nor Zaihar Yahaya ◽  
Zuhairi Baharudin

The objective of this paper is to design a multi-input dc-ac inverter integrated photovoltaic array, wind turbine and fuel cell in order to simplify the hybrid power system and reduce the cost.  The output power characteristics of the photovoltaic array, wind turbine and fuel cell are introduced. The operational principle and technical details of the proposed multi-input dc-ac inverter is then explained. The proposed inverter consists of a three input flyback dc-dc converter and a single phase full bridge dc-ac inverter. The control strategy for the proposed inverter to distribute the power reasonably to the sources and it achieved a priority of the new energy utilization is discussed. This multi-input dc-ac inverter is capable of being operated in five conditions and power delivered to the ac load can be either individually or simultaneously. First to third condition occurs when the power delivered from either renewable energy sources individually, fourth condition happens when power is demanded from two sources simultaneously, and finally when power are available from three sources simultaneously. The proposed inverter has been simulated by employing NI Multisim 12.0 circuit simulator.


Author(s):  
Mohd Azman Rosli ◽  
Nor Zaihar Yahaya ◽  
Zuhairi Baharudin

The objective of this paper is to design a multi-input dc-ac inverter integrated photovoltaic array, wind turbine and fuel cell in order to simplify the hybrid power system and reduce the cost.  The output power characteristics of the photovoltaic array, wind turbine and fuel cell are introduced. The operational principle and technical details of the proposed multi-input dc-ac inverter is then explained. The proposed inverter consists of a three input flyback dc-dc converter and a single phase full bridge dc-ac inverter. The control strategy for the proposed inverter to distribute the power reasonably to the sources and it achieved a priority of the new energy utilization is discussed. This multi-input dc-ac inverter is capable of being operated in five conditions and power delivered to the ac load can be either individually or simultaneously. First to third condition occurs when the power delivered from either renewable energy sources individually, fourth condition happens when power is demanded from two sources simultaneously, and finally when power are available from three sources simultaneously. The proposed inverter has been simulated by employing NI Multisim 12.0 circuit simulator.


Author(s):  
S. G. Ignatiev ◽  
S. V. Kiseleva

Optimization of the autonomous wind-diesel plants composition and of their power for guaranteed energy supply, despite the long history of research, the diversity of approaches and methods, is an urgent problem. In this paper, a detailed analysis of the wind energy characteristics is proposed to shape an autonomous power system for a guaranteed power supply with predominance wind energy. The analysis was carried out on the basis of wind speed measurements in the south of the European part of Russia during 8 months at different heights with a discreteness of 10 minutes. As a result, we have obtained a sequence of average daily wind speeds and the sequences constructed by arbitrary variations in the distribution of average daily wind speeds in this interval. These sequences have been used to calculate energy balances in systems (wind turbines + diesel generator + consumer with constant and limited daily energy demand) and (wind turbines + diesel generator + consumer with constant and limited daily energy demand + energy storage). In order to maximize the use of wind energy, the wind turbine integrally for the period in question is assumed to produce the required amount of energy. For the generality of consideration, we have introduced the relative values of the required energy, relative energy produced by the wind turbine and the diesel generator and relative storage capacity by normalizing them to the swept area of the wind wheel. The paper shows the effect of the average wind speed over the period on the energy characteristics of the system (wind turbine + diesel generator + consumer). It was found that the wind turbine energy produced, wind turbine energy used by the consumer, fuel consumption, and fuel economy depend (close to cubic dependence) upon the specified average wind speed. It was found that, for the same system with a limited amount of required energy and high average wind speed over the period, the wind turbines with lower generator power and smaller wind wheel radius use wind energy more efficiently than the wind turbines with higher generator power and larger wind wheel radius at less average wind speed. For the system (wind turbine + diesel generator + energy storage + consumer) with increasing average speed for a given amount of energy required, which in general is covered by the energy production of wind turbines for the period, the maximum size capacity of the storage device decreases. With decreasing the energy storage capacity, the influence of the random nature of the change in wind speed decreases, and at some values of the relative capacity, it can be neglected.


2018 ◽  
Vol 8 (10) ◽  
pp. 1848 ◽  
Author(s):  
Arman Oshnoei ◽  
Rahmat Khezri ◽  
SM Muyeen ◽  
Frede Blaabjerg

Wind farms can contribute to ancillary services to the power system, by advancing and adopting new control techniques in existing, and also in new, wind turbine generator systems. One of the most important aspects of ancillary service related to wind farms is frequency regulation, which is partitioned into inertial response, primary control, and supplementary control or automatic generation control (AGC). The contribution of wind farms for the first two is well addressed in literature; however, the AGC and its associated controls require more attention. In this paper, in the first step, the contribution of wind farms in supplementary/load frequency control of AGC is overviewed. As second step, a fractional order proportional-integral-differential (FOPID) controller is proposed to control the governor speed of wind turbine to contribute to the AGC. The performance of FOPID controller is compared with classic proportional-integral-differential (PID) controller, to demonstrate the efficacy of the proposed control method in the frequency regulation of a two-area power system. Furthermore, the effect of penetration level of wind farms on the load frequency control is analyzed.


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