The work presented in this paper is carried out with the objective of identifying the optimal location and size (Kvar ratings) of shunt capacitors to be placed in radial distribution system, to have overall economy considering the saving due to energy loss minimization. To achieve this objective, a two stage methodology is adopted in this paper. In the first stage, the base case load flow of uncompensated distribution system is carried out. On the basis of base case load flow solution, Nominal voltage magnitudes and Loss Sensitivity Factors are calculated and the weak buses are selected for capacitor placement.In the second stage, Particle Swarm Optimization (PSO) algorithm is used to identify the size of the capacitors to be placed at the selected buses for minimizing the power loss. The developed algorithm is tested for 10-bus, 34-bus and 85-bus Radial Distribution Systems. The results show that there has been an enhancement in voltage profile and reduction in power loss thus resulting in much annual saving.

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This paper presents an artificial neural network (ANN) based frequency controller design for multi-area Automatic Generation Control (AGC) scheme in a deregulated electricity market. The effect of Superconducting Magnetic Energy Storage (SMES) unit has also been considered to develop the model. SMES units have been used to the power systems to inject or absorb active power. The effect of generator rate constraint (GRC) has also been considered in developing the multi area AGC model. A three layer feed forward neural network (NN) is proposed for controller design and trained with Back propagation algorithm (BPA). The poolco based transaction can be implemented by optimizing the bids (price & capacity) submitted by the generating companies (Gencos) and distribution companies (Discos). The functioning of the proposed ANN based controller has been demonstrated on a four-area System, and the results have been compared with those obtained by using a Genetic Algorithm based control scheme.

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Today"s world is very much concerned to reduce green house gas emission from the conventional thermal power plants as cutting down emissions from transport and heating sector may not be realistic in the near future. To reduce pollution from electrical power sources, the world is now marching towards usage of renewable energy sources (RESs). These sources being small in capacity are mostly connected at the distribution voltage level. This indirectly reduces transmission and distribution losses as the sources are around the load. This distribution system having small scale energy sources is called as a microgrid or active distribution network. Microgrid operates generally in a grid connected mode. However, circumstances such as fault, voltage sag and large frequency oscillations in the main grid may force the active distribution network to be disconnected from the main grid and operate as an isolated microgrid. During this isolation there will be change in power output from the controllable microsources which are to be regulated properly to have a stable operation in regard to power balance and frequency of operation within the isolated microgrid. An autonomous isolated microgrid comprising both controllable & uncontrollable sources. Like solar, wind, diesel generator (DG), aqua electrolyzer (AE), fuel cell (FC), a battery energy storage system (BESS), and fly wheel (FW) are considered. Solar, wind, DG and FC are power generating source & BESS, FW, AE as energy storage element. The generated hydrogen by an AE is used as fuel for a FC. The power system frequency deviates for the sudden change in load demand and the real power generation. The output power of DG, FC, BESS, FW and power absorbed by AE is regulated by using controller such that frequency of the system is controlled. Controller used is proportional plus integral plus derivative (PID). Load Disturbance Rejection (LDR) is used for tuning of controller gains of the proposed hybrid system. This uses the chien-hornes-resnick (CHR) setting with 20% overshoot. Design of p-f droop (frequency regulation parameter) for different controllable source in microgrid using bode plot stability criterion. The system response with Modified LDR based controller, LDR based controller and classical controller are compared. Investigation shows that Modified LDR based controller gives best response amongst these three methods.