Satyendra Pratap Singh

A smart volt-var optimization engine for energy distribution system

Volt-Var Optimization (VVO) is a renovated smart grid technology that utilized the advance smart grid assets such as Advance Metering Infrastructure (AMI), Distribution Management System (DMS) and Advanced Communication System. VVO offers energy savings with associated reduction in green house gas emission and other directly or indirectly benefits to customers and/or utilities. The main function of the VVO is to determine the operational setting of volt/var control devices, to minimize the system loss of the distribution network and switching operation of the On-load Tap Changer (OLTC), Automatic Voltage Regulator (AVR), and Capacitor Banks (CBs). VVO is an advanced method that optimizes voltage and/or reactive power (VAR) of a distribution network based on predetermined aggregated feeder load profile. This paper presents a critical review of VVO/CVR technology with traditional and existing techniques in the era of smart grid. A Smart Volt-Var optimization engine also proposed for medium and low voltage distribution feeders.

Islanding based optimal placement of phasor measurement unit using MILP

Reliability and stability of power system are the main concern of power industry. However, increasing demands for energy increases the risk factor due to non-linearity of the power system. Sometimes, a small disturbance may create the chain of disturbances and results in a blackout. To avoid this eventuality, intensely islanding is the key option in which some area of the power system is detached from the affected area. This paper proposed a Mixed Integer Linear Programming (MILP) based optimal placement of Phasor Measurement Units (PMUs) which provides the full observability of power system before and after the islanding of system. Maximum redundancy of the optimal number of PMUs is the additional feature of proposed method which increases the performance of state estimation. Single PMU outage case has been considered as a contingency in this paper, and the presence of zero injection buses has also been considered. All the simulations have been performed in Matlab and tested on IEEE 14-bus, IEEE 30-bus, IEEE 118-bus and New England 39-bus test systems. To check the effectiveness of proposed method, results have been compared with methods available in the literature.

Pseudo PMU for quasi-static analysis of power system

The Phasor Measurement Units (PMU) are being integrated into the power grids for enhanced monitoring and control of the power system. PMUs data are useful for postmortem analysis and development of real-time control of the Power system. In this paper, a pseudo PMU is proposed for the quasi-static analysis of the Power System. The emulation has been done by avoiding the realization of data communication and emulating only those features of PMU essential for monitoring of power system. Considering economic feasibility, deployment of PMU at each bus is not economical, hence for optimal location of PMUs an integer linear programming (ILP) has been proposed in this paper. For the location of PMUs pseudo-PMU are used, and quasi-static analysis of IEEE 24-bus RTS system is done in MATLAB environment. The results illustrate the efficacy of proposed method for quasi-static analysis of Power System.

Frequency stability analysis of hybrid power system based on solar PV with SMEs unit

Storage Technology has emerged as main backup powers provider in the era of Smart Grid. Frequency stability analysis of a hybrid power system (HPS) based on solar PV and Superconducting Magnetic Energy Storage system (SMES) unit have discussed in this paper. Generally frequency instability problem occurs due to abrupt variation in load demand growth and generated power variations from different renewable power sources. To Solve these fluctuating problem, renewable power generators are equipped with various storage system. On the bases of frequency stability, effect of enabling the SMEs operation with the HPS has also been analyzed in this paper. HPS model has simulated in two different cases. First one is the steady state analysis with controller and another is dynamic operation of the system throughout a day. Genetic Algorithm is used for optimizing the controllers parameter. In the presence of large disturbance the effect of limited storage capability of SMES unit as large disturbance is also being considered. Matlab/Simulink platform is used for analyzing the HPS model. From Simulation results it is observed that SMES unit can mitigate the frequency fluctuations and improves system stability in both cases for variable PV power and uneven demand loads.

Synchronized PMU placement incorporating communication infrastructure

Phasor Measurement Unit (PMU) provides the online state estimation and faster monitoring, protection and control of power system. However, PMU installation at every power system buses is an uneconomical decision. Vowing to this, various methodologies have been suggested in past to determine the optimal locations of these devices in order to retain the observability of the system. However, the costs of communication infrastructure from Phasor Data Concentrator (PDC) to PMUs have not been given proper attention. In order to address this issue, the PMU placement problem has been formulated incorporating cost of communication infrastructure also in this paper. The resulting problem has been solved using Mixed Integer Linear Programming (MILP) method. The results obtained for IEEE 14-bus and IEEE 30-bus systems have been compared with another method in the literature. The test results reveal that the proposed methodology produced the optimal PMU with higher observability and lesser path for establishing communication link compared to an existing method.

Voltage stability assessment using Phasor Measurement Units in power network with full system observability

This paper presents the assessment methodology for voltage stability using Phasor Measurement Unit (PMU) with complete system observability. For full power system observability, the PMU placement is considered with and without conventional power flow as well as injection measurement such that minimum number of PMUs is used. Data obtained by PMUs are used for voltage stability assessment with the help of L-Index. As the PMU gives real time voltage and current phasors and L-index is dependent on voltage and admittance values, thus the L-index so obtained can be used as real time voltage stability indicator. The case study has been carried out on IEEE-14 bus system.

Energy savings in distribution network with smart grid-enabled CVR and distributed generation

When conservation of voltage is applied aiming to the reduction in energy consumptions by lowering the voltage in such an effective and controlled manner so that it does not violate ANSI Standard C84 voltage limits known as Conservation of Voltage Reduction (CVR). However enabling of CVR with traditional methods is limited with voltage reduction range and without taking account of customer end voltage. This paper proposes a smart grid enabled CVR operation which considers the customer end voltage through advanced metering infrastructure (AMI) and controls the volt-var control (VVC) device settings of distribution feeder with the advance distribution management system (ADMS) and VVC server. An additional reactive power support has been injected through DGs during the deeper level of voltage reduction to maintain the feeder voltage profile within limits. The Effect of penetration of distributed generations during CVR operation is also being incorporated. IEEE 13 node test feeder of radial distribution network has been considered for analysis of CVR effect. The test system is modeled and simulated in Open distribution system simulator (OpenDSS) environment. From simulation results, it is observed that significant energy consumptions and peak load demand can be reduced with combined operation of smart grid enabled CVR and distributed generations with proper feeder voltage profile.