Model predictive current controller for performance enhancement of grid-integrated single-phase photovoltaic distributed generation plants

2016 ◽  
Vol 40 (3) ◽  
pp. 762-775 ◽  
Author(s):  
Aditi Chatterjee ◽  
Kanungobarada Mohanty ◽  
Vinaya Sagar Kommukuri ◽  
Kishor Thakre

Acknowledgement of renewable sources of energy as substitute energy sources for power production has expanded the number of distributed generation plants being incorporated into the conventional power distribution system. The single-phase voltage source inverter allying the photovoltaic plant with the grid has to address various issues identified with the quality of current injected into the grid, output power factor and power exchange between the plant and the grid. This paper concentrates on the investigation, design and implementation of a digital predictive current control technique known as the model predictive current controller for the control of single-phase photovoltaic distributed generation plants. The performance of the controller is evaluated under varied operating conditions. The proposed current controller is compared with the conventional proportional–integral controller in terms of its design methodology, steady state and dynamic response. The simulation and experimental results validates the effectiveness of the proposed model predictive current controller.

2010 ◽  
Vol 61 (4) ◽  
pp. 193-204 ◽  
Author(s):  
Reza Noroozian ◽  
Mehrdad Abedi ◽  
Gevorg Gharehpetian

Combined Operation of AC and DC Distribution System with Distributed Generation Units This paper presents a DC distribution system which has been supplied by external AC systems as well as local DG units in order to demonstrate an overall solution to power quality issue. In this paper, the proposed operation method is demonstrated by simulation of power transfer between external AC systems, DG units, AC and DC loads. The power flow control in DC distribution system has been achieved by network converters and DG converters. Also, the mathematical model of the network, DG and load converters are obtained by using the average technique, which allows converter systems accurately simulated and control strategies for this converters is achieved. A suitable control strategy for network converters has been proposed that involves DC voltage droop regulator and novel instantaneous power regulation scheme. Also, a novel control technique has been proposed for DG converters. In this paper, a novel control system based on stationary and synchronously rotating reference frame has been proposed for load converters for supplying AC loads connected to the DC bus by balanced voltages. The several case studies have been studied based on proposed methods. The simulation results show that DC distribution systems including DG units can improve the power quality at the point of common coupling (PCC) in the power distribution system or industrial power system.


Author(s):  
Hasham Khan

The rapid increase in the population and fastest development in the industrial sector has increased the energy demand throughout the world. Frequent outages and load shedding has seriously deteriorated the efficiency of the electrical power distribution system. Under such circumstances, the implementation of Distributed Generation (DG) is increasing. Small hydel generators are considered as the most-clean and economical for generating electrical energy. These are very complex nonlinear generators which usually exhibits low frequency electromechanical oscillations due to insufficient damping caused by severe operating conditions. These DGs are not connected to the utility in many cases because, under varying load, they cannot maintain the frequency to the permissible value. This work presents detailed analysis of operating characteristics and proposes a hybrid frequency control strategy of the small hydel systems. The simulation and testing is performed in MATLAB, the results verified the improved performance with the recommended method. The proposed method conserves half of the power consumption. The control scheme regulates the dump load by connecting and disconnecting it affectively. The application of presented methodology is convenient in the deregulated environment, especially under the severe shortage of energy. The proposed model keeps the frequency of system at desired level. It reduces the noise, thereby improving the response time of the designed controller as compared to conventional controllers. The innovative scheme also provides power for small scale industrial, agricultural and other domestic application of far-off areas where the supply of utility main grid is difficult to provide. The recommended scheme is environmental friendly and easy to implement wherever small hydel resources are available.


2012 ◽  
Vol 2012 (1) ◽  
pp. 001081-001084 ◽  
Author(s):  
Jesse Bowman ◽  
A. Ege Engin

When integrating sensitive RF analog devices with complex VLSI digital components, simultaneously switching drivers cause supply voltage fluctuations which can propagate both horizontally and vertically between the power/ground planes. The same voltage source on a printed circuit board can be shared to increase power efficiency and reduce space used. In order to accomplish this, on board filtering is needed to isolate the noise between these two types of devices for proper operation. Hence, accurate estimation and improvement of the performance of power/ground planes is critical in a mixed-signal system. We present a new method to minimize the noise transfer at high frequencies to the power distribution system, called the Virtual Ground Fence. At its basic level, the Virtual Ground Fence consists of quarter-wave transmission-line stubs that act as short circuits between power and ground planes at their design frequency. We will present various configurations of Virtual Ground Fence for different coupling scenarios.


2019 ◽  
Vol 2019 ◽  
pp. 1-19 ◽  
Author(s):  
Naveed Ashraf ◽  
Tahir Izhar ◽  
Ghulam Abbas

The suggested single-phase ac-to-ac matrix converter operated with inverting and noninverting characteristics may solve the grid voltage swell and sag problem in power distribution system, respectively. It is also employed as a direct frequency changer for domestic induction heating. The output voltage is regulated through duty cycle control of high frequency direct PWM (DPWM) and indirect PWM (IDPWM) switching devices. The DPWM control switches control the switching states of IDPWM switching devices. The inverting and noninverting characteristics are achieved with low voltage stresses and hence low dv/dt across the high and low frequency-controlled switches. This reduces their voltage rating and losses. The high voltage overshoot problem in frequency step-up operation is also analyzed. The sliding mode (SM) controller is employed to solve this problem. Pulse selective approach determines the power quality of load voltage. The validity of the mathematically computed values is carried out by modelling the proposed topology in MATLAB/Simulink environment and through hardware results.


Author(s):  
Zuhaila Mat Yasin ◽  
Izni Nadhirah Sam’ón ◽  
Norziana Aminudin ◽  
Nur Ashida Salim ◽  
Hasmaini Mohamad

<p>Monitoring fault current is very important in power system protection. Therefore, the impact of installing Distributed Generation (DG) on the fault current is investigated in this paper. Three types of fault currents which are single line-to-ground, double line-to-ground and three phase fault are analyzed at various fault locations. The optimal location of DG was identified heuristically using power system simulation program for planning, design and analysis of distribution system (PSS/Adept). The simulation was conducted by observing the power losses of the test system by installing DG at each load buses. Bus with minimum power loss was chosen as the optimal location of DG. In order to study the impact of DG to the fault current, various locations and sizes of DG were also selected. The simulations were conducted on IEEE 33-bus distribution test system and IEEE 69-bus distribution test system. The results showed that the impact of DG to the fault current is significant especially when fault occurs at busses near to DG location.</p>


2013 ◽  
Vol 860-863 ◽  
pp. 2007-2012 ◽  
Author(s):  
Xiao Meng ◽  
Neng Ling Tai ◽  
Yan Hu ◽  
Xia Yang

The failure current in resonant grounder power distribution system is small, so it is difficult to detect the fault feeder. This passage presents the equivalent circuit of resonant grounded system, and discusses the difference of electrical characteristics between faulty feeder and sound feeders by using shunt resistors. To reduce the influence of shunt resistors on the system and improve the detection sensitivity, it presents the method of shunting multi-level resistors, and it proves the sensitivity and reliability of this method by EMTP simulation.


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