Mohammad Yusri Hassan

Mathematical model of Compressed Air Energy Storage in smoothing 2MW wind turbine

This paper presents the mathematical modeling of Compressed Air Energy Storage, (CAES) in obtaining mechanical power generated from expander. Mechanical power is injected to a generator to generate electricity that will stabilize 2MW active power fluctuated caused by intermittent behavior of wind speed. The control system in maintaining dc-link voltage at constant value and control system in supplying generated power from CAES is also discussed here. The goals in using CAES are to smooth out the fluctuated power and increased low power integrated into the grid. This system is analyzed using SimPowerSystem of MATLAB/simulink. Results show that the jCAES is able to not only mitigate generated power but it also can promise constant power generated to grid even at low wind speed.

A review on optimal placement methods of distribution generation sources

Distributed Generation (DG) sources have attracted serious attention due to their potential solution for some issues, like the deregulation in power system, increasing the power consumption and the shortage of transmission capacities. The optimal placement of DG is necessary for maximizing the DG potential benefits in power system such as maintaining and/or improving reliability and stability. There are several research studies to determine the optimal DG location by their imposed constraints and objectives. However, the systematic principle for this issue is still an unsolved problem. This paper is reviewed some of the most popular DG placement methods, including 2/3 Rule, Analytical Methods, Optimal Power Flow and Evolutionary Computational Methods (Genetic Algorithm, Fuzzy Systems and Tabu Search). The related applications and advantages of each technique are expressed briefly. This paper provides helpful information and resources for the future studies in this area.

Improving the MW-Mile Method Using the Power Factor-Based Approach for Pricing the Transmission Services

The MW-Mile method is an embedded cost pricing method, which is widely used to determine transmission pricing. The method is formulated based on the distance and active power flow in each line of the transmission network. This method may be considered as the first pricing strategy proposed for recovering the fixed transmission cost, based on the actual use of the transmission network. However, this method suffers from the provision of unfair charges to the users, since it ignores the quality of the load in allocating the transmission cost. This paper proposes an improved MW-Mile method by considering not only the changes in MW flows but also the quality of the load, i.e., the power factor. In this study, the IEEE 14-bus system was used to illustrate the contribution of the proposed method in allocating transmission cost to the user in a fair manner.

Transmission Congestion Management Assessment in Deregulated Electricity Market

The open access to the transmission network has resulted the problem of management of the transmission system due to congestion. Congestion occurs when the transmission network is not sufficient to transfer electric power according to the market desire. There are several alternatives schemes suitable for different electricity market structures have been proposed to manage the transmission congestion such as re- dispatching existing generators or dispatching generators outside the congested area to supply power. In both alternatives, congestion has costs based on differences in energy prices. Furthermore, many approaches for the congestion cost allocation and pricing have been proposed and intensely discussed in literature. However, as far as the congestion cost allocation and pricing approaches are concerned the charge due the congestion only collected from the customer (load). For example, in the case of nodal pricing, the payment collected from the consumer is in excess of the payment paid to generators. Similarly in the case of uplift cost approach, the congestion cost is only shared by consumers. These leads to unreasonable results since the generators do not care for the operation condition. This paper presents an assessment of transmission congestion management in the deregulated electricity market. Comparison among the existing methods in allocating the congestion charge to the participants is highlighted. The case study based on 3 bus system is used to illustrate the pro and con of these methods.

Demand Side Management Using Direct Load Control for Residential

Dramatic increase in the number of domestic consumers due to mass electrification will have implications for the national generation, transmission and distribution. The nature of the domestic load coincides with the evening peak which is more expensive to generate. This indicates the need for demand side management (DSM) in residential as a strategy to reduce the impact of domestic peaks on the national electricity load and related costs. This paper describes the software development written in Visual C++ 6.0 to control directly the residential loads through communicating with parallel port. Graphic user interface (GUI) was designed for the software. Comparison was done between load curve without controller and with controller. The result shows a reduction in energy consumption with the application of DSM controller. Hence, DSM application improves the management of both power and energy consumptions.

Optimisation of pumped-hydro storage system for hybrid power system using power pinch analysis

Storage technology in Hybrid Power System (HPS) is urgently required to adapt with the mismatch between the renewable energy (RE) production and the time distribution of load demands. Different storage systems incur different types and amount of losses depending on the power conditioning as well as storage system efficiencies. This work focuses on the design of HPS with pumped hydro storage systems using Power Pinch Analysis (PoPA). The previously developed modified Storage Cascade Table (SCT) for HPS with battery storage is adapted to calculate losses associated with the pumped hydro storage system. The demonstration of the method on an Illustrative Case Study shows that the application of pumped hydro storage in HPS yield lower total losses in the system. The maximum power demand target is reduced while the targeted maximum storage capacity is increased compared to when battery storage is applied.

Power optimization for a small-sized stall-regulated variable-speed wind turbine

This paper focuses on power optimization for a small-sized stall-regulated variable-speed (SS-SR-VS) wind turbine system. In this paper, the behavior of the SS-SR-VS wind turbine during power optimization is demonstrated. The Speed Loop Control method with the assistance of classical Proportional Integral (PI) controller is used. Controller parameter is designed based on the linearization process, and the pole-placement procedure has been applied during the controller tuning. Further improvement is then done by using the Good Gain method. The comparison between these two methods is presented. Results show that the turbine speed, generator speed and hence the generated power can be optimized at the optimum values corresponding to the wind speed variations during power optimization.

Modeling and simulation of grid connected Photovoltaic System for Malaysian climate using Matlab/Simulink

The impact of solar irradiance, ambient temperature and clearness index on the outdoor performance of poly-crystalline (poly-Si) PV modules is considered. This paper highlights the effect on the energy output by changing the clearness index for the Building Integrated Photovoltaic System (BIPV) in Malaysia. Simulation was implemented using MATLAB/SIMULINK and results are compared with the actual monitored data. A case study was presented for a 45.36 kWh system using poly-crystalline module and results show that the energy output differs from 7.23% to 8.52% with clearness index of 0.55 and hence clearness index also influenced the energy output besides solar irradiance and temperature.

Certain Considerations In Pricing Unbundled Transmission Services

In deregulated environment, the transmission network is considered to be the key factor of the electricity markets. One of the important issues in this context is how to charge the users for the use of transmission facilities in the fair way and at the same time allowing the transmission utilities to recover their transmission costs. Several methodologies have been developed to recover the cost of transmission services and to estimate the power contributed by single generating unit in lines and loads. Both developed methods attempt to allocate the charge of the use of the transmission system. This paper describes certain aspects to be considered in pricing the unbundled transmission services. These aspects cover the type of transmission services, the costs related to the services and the methods used to calculate the costs of transmission services. This paper also proposes a new approach to allocate the costs of the transmission services among the transmission user utilising the properties of MW-mile based method. A case study based on a 6-bus system is used to highlight the merit of the proposed approach over the existing approaches. The case study results show that the proposed approach provides a better economic signal in allocating the charges to the transmission user.

A Distribution Network Reconfiguration based on PSO: Considering DGs sizing and allocation evaluation for voltage profile improvement

The optimized network reconfiguration and Distributed Generations (DG) sizing with allocation instantaneously via Particle Swarm Optimization (PSO) proposed a new way of allocation DG based on low voltage profile. This method consists of three steps. It started with categorized the switching sequences for radial network configuration while observe the P losses and the profile of voltage without DG. The second step is reconfiguration feeder for reduce losses via DGs allocation based on substations geographical location. The final step is sizing and allocation DGs at each bus with low voltage profile produced from the first step, used to mend the voltage profile and minimize the Plosses also compared the result with the geographical based allocation results. The objective of this study is to mend the voltage profile while decreasing the Plosses by using optimization technique considering network reconfiguration, DGs Sizing and allocation concurrently. Four cases are compared which is case 1 is the initial case and taken as a reference. All three stages are tested on standards IEEE 33 bus system by using Particle Swarm Optimization (PSO) technique in MATLAB software. This method proved that improvement of Plosses and voltage profile has been made by change of the switching topology with DGs sizing and allocation technique respectively.