power system operating problems

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(Deep) Reinforcement learning for electric power system control and related problems: A short review and perspectives

(Deep) Reinforcement learning for electric power system control and related problems: A short review and perspectives

by false data injection attack on voltage control of a power system. Test re- sults revealed if even a few substations are attacked a voltage collapse with its consequences can happen in the system. Power system state estimation under cyber attacks was considered in [82, 84, 85]. Secure state estima- tion with assumption that measurements are sent over a wireless networks under jamming attacks was dealt in [82] and the antijamming game frame- work for secure state estimation using multi-agent reinforcement learning to determine optimal path against an intelligent attacker. Reference [85] con- sidered secure state estimation with risk-averse transmission path selection method that is based on RL idea and demonstrated how proposed approach can improve secure state estimation robustness. DRL method (DQN) was proposed in [84] to defend against data integrity attacks in power systems state estimation. These types of cyber attacks are able to bypass the bad data detection mechanism in state estimation and make the system operator and controllers obtain the misleading states of system. In [86] the on-line attack detection problem was formulated as a partially observable Markov decision process (Markov property recovered through the use of a window of state history)and on-line detection algorithm using SARSA method was proposed for early cyber attacks detection. Recent work presented in [87] discusses te use of RL in a general framework of cognitive risk control for cyber attacks in smart grids. RL was proposed in [88] to evaluate false data injection attacks on automatic voltage control of power systems (in normal operating states). A Q-learning algorithm with nearest sequence memory is adopted for on-line learning of attacking strategy and optimal attack strat- egy is modelled as a partially observable Markov decision process. Based on kernel density estimation, a bad data detection and correction method were presented to mitigate the disruptive impacts of the attacks.
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Utilities operating nuclear power

Utilities operating nuclear power

U tilities operating nuclear power plants have been dealing with elec- tromagnetic interference (EMI) problems for over two decades. Many early problems that affected the operation of in- strumentation and control (I&C) equipment in plants stemmed from the use of wireless transmission devices (WTDs) (e.g., radio walkie-talkies, cellular phones, etc) inside the plant in the vicinity of system cabinets and cable trays carrying bundles of cables. A simple and partially effective method of reducing EMI events caused by WTDs has been to mark off exclusions zones around system cabinets and areas where I&C equip- ment is installed. The use of these zones has presented some problems for existing plants. For example, some plants have had to expand the area of some zones that became ineffective upon the use of new WTDs that evidently presented an increased risk to the operation and EMI protection of I&C equip- ment. The sizes of some expanded zones are larger than 2,000 square feet. In addition, some zones encroach upon human traffic areas used by plant personnel to move from area to area within a plant.
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IQ Power TM Static Neutralizing System MPS Power Supply INSTALLATION AND OPERATING INSTRUCTIONS

IQ Power TM Static Neutralizing System MPS Power Supply INSTALLATION AND OPERATING INSTRUCTIONS

A. Determine location for mounting the static bar. The static bar will typically be located just ahead of where problems due to static are occurring. A static audit by a Simco-Ion representative can determine the best location for the static bar. B. The appropriate operating distance, “R” (see Static Bar Installation diagram) for the IQ Power static bar is in part determined by the application. IQ Power LP static bars should be mounted between 50 and 230 millimeters [2 to 9 inches] from the web and may be installed in more congested areas of the machine, however the web path should be fixed. Optimum mounting distance for high speed webs is 100 mm [4 inches]. IQ Power LP bars have an ion emitter to emitter spacing of 30 mm [1.18 inches].
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A Simulation Model for Reactive Power Compensation

A Simulation Model for Reactive Power Compensation

Reactive power control has been looked at as an important issue in distribution systems for many reasons [4].First, the need for most efficient operation of power systems has increased with the price of fuel. For a given distribution of power, the losses in the system can be reduced by minimizing the flow of reactive power. Second, the extension of the power network specially in the distribution level, has been curtailed in general by high interest rates, and in particular cases by right-of-way. In many cases power transmitted through older networks has been increased, requiring the application of reactive power control measures to restore stability margins. Third, voltage is considered as one of the most important parameters of the quality of power supply. Its deviation from the normal value may be harmful and expensive. Reactive power control is an essential tool in maintaining the quality of supply. An extensive amount of research has appeared dealing with reactive power control in power systems. In general, most of this research falls within the following subgroups of the Var/voltage control problems. The reactive power planning and operation is an optimization problem of nonlinear, non-smooth, and non-continuous function. It is one of the most complex problems of power systems because it is requires the simultaneous minimization of real power losses to reduce the operating cost and improve the voltage profile, and the cost of additional reactive power sources [5].Capacitors are widely installed on Distribution systems for reactive power compensation to improve the voltage profile and to reduce power and energy losses in the system. The extent of these benefits depends upon how the capacitors are placed in the network and how effective the control schemes designed for them are. The general capacitor placement problem consists of determining the optimal number location, types, and sizes of new and existing capacitors and their control schemes, such that objective function (savings associated with the capacitor placement minus the cost of capacitors )is maximized while the load and operation constraints (voltage magnitude, current flow rating, etc)at different load levels are satisfied.[6]
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ACCOUNTING SYSTEM OF OPERATING AND NON OPERATING INCOMES OF POWER COMPANIES: AN OVERVIEW

ACCOUNTING SYSTEM OF OPERATING AND NON OPERATING INCOMES OF POWER COMPANIES: AN OVERVIEW

Accounting is often called the language of business through which the business entity communicates with the outer world. In order to make the language of accounting to convey the same meaning to all people as far as practicable, it is necessary that is should be based on certain uniform and scientifically laid down standards. So the accountants from all over the world have developed certain rules, procedures and conventions that represent a consensus of the profession of a good accounting practices and procedures and are generally referred as „Generally Accepted Accounting Principles‟ (GAAP). In the simple words, it can be stated that generally accepted accounting principles, concepts and conventions are the fundamental rules of Accounting which are universally used and accepted by the accountants all over the world as general guidelines for preparing accounting statements. In other words, the rules and conventions of accounting are commonly referred to as principles. The word principle is here used to mean a general law or a rule adopted or professed as a guide to action; or a settled basis of conduct or practice. These principles have developed in accordance with usage, experience, historical precedents, and professional bodies, government regulations with the passage of time and with changing needs of business. Under the hybrid of the accrual and cash system of accounting, expenses are reflected in the accounts for the period in which they accrue whereas incomes are reflected in the accounts for the period in which they are received. This system is adopted in the institution in which the revenues are uncertain but the expenses are fixed. This system follows the convention of conservatism and „Receipts and Expenditure Account‟ is prepared on this basis by the institutions such as local authorities, professionals and government institutions. In this paper I have discussed about the Accounting System of Operating and Non-Operating Incomes of Power Companies.
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Development Of A Portable Power Measurement System For Electric Sanitation Vehicle

Development Of A Portable Power Measurement System For Electric Sanitation Vehicle

From the results, the peak power and the peak current reach about 9kW and 130A respectively and the average power of full and no-load are about 4.5kW and 4kW respectively in the vehicle travel mode. The electric sanitation vehicle is driven by a 5.5kW DC motor with the rated current of 89A. However the motor can satisfy the power demand of the vehicle travel at maximum stable speed. But the ESV is used for collecting garbage from many garbage bins and it needs frequent acceleration. So it is possible that the motor becomes overheated and the maximum current should be limited at lower value.
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Performance Improvement and Evaluation of Grid connected Hybrid power system

Performance Improvement and Evaluation of Grid connected Hybrid power system

282 During tracking time, the PV output is less than its maximum power. This means that, longer the conversion time is, larger the power loss [7],[8]. On the contrary, if the execution speed of the P&O method increases, then the system loss will decrease. Moreover, this method only requires two sensors, which results in a reduction of hardware requirements and cost. Therefore, the P&O method is used to control the MPPT [9][10] process. The power-feedback control is used to achieve maximum power. As PV voltage and current are determined, the power is calculated. The maximum power point can be achieved by changing the reference voltage by the amount of ΔV ref . In order to implement the MPPT algorithm, a
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HP StorageWorks X1000 G2 Network Storage Systems Overview

HP StorageWorks X1000 G2 Network Storage Systems Overview

Patented replication and failover technology continuously captures byte-level data changes as they occur in your production environment and replicates those changes to one or more servers in any location without geographic limitations. By replicating only the bytes that change, Storage Mirroring Software uses the absolute minimum bandwidth required to replicate customer data. The software does not require special hardware to run and utilizes existing LAN or WAN infrastructure -saving time, additional investment, and maintenance. Storage Mirroring software is storage independent and will support any DAS, NAS, and SAN storage device. Additional flexibility is achieved with Windows and Linux operating system support. Storage Mirroring works on Windows Server 2003, Windows Server 2008, Windows Storage Server, 64-bit Windows, Windows on Itanium and Red Hat Linux. The platform flexibility, resource optimization, and application-specific protection enable customers to solidify their data and disaster protection strategies.
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A Study to Investigate the Power Quality Issues for Using DVR to Mitigate Voltage Sag

A Study to Investigate the Power Quality Issues for Using DVR to Mitigate Voltage Sag

malfunctioning of sensitive loads etc. Modern Power system is a complex network, hundreds of power generating stations and thousands of load centers are interconnected with the help of long lines of power transmission and distribution networks. Today, consumer’s main concern is the quality and reliability of supplied power at the various load centers. With the help of advance technologies, the modern industries are trying to extract and develop the new technology to achieve their predefined industrial goals. Every industry wants to optimize their production at the same time minimizing the cost of production so that a maximum profit can be achieved. Such production process requires a guarantee of stable and un-interrupted power supply. The main reason for the demand of a high quality power is these modern manufacturing processes and equipment. They require high efficiency with high quality of power for the operation of these machines. Most of the components of such machines are sophisticated and sensitive. Industries can go through a major financial loss if they go through shut down due to unavailability of required quality power[2]. Voltage dips in the supply is mainly caused by the faults in the grid as well as the fault clearing time taken by the devices used for protection. This fault clearing time mainly decides the voltage dip duration time. There can be various origins for such faults: (i) Faults in Transmission system. (ii) Due to starting of large motors.(iii) Various Fuses.(iv) Faults in remote distribution system.(v) Faults in Local distribution system. (vi) Short term Interruptions.
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Overview and Literature Survey of Power System Stabilizer In Power Systems

Overview and Literature Survey of Power System Stabilizer In Power Systems

Artificial Bee Colony proposed by Karaboga [102-104] is a new technique proposed to optimize the parameters settings of CPSS. PSS parameters settings are computed using linear control theory [105]. Simulation results show the effectiveness and robustness of the proposed ABCPSSs over CPSSs. Another version of ABC is Interactive ABC, Investigations reveal the performance of IABC based multiband power system stabilizers in a multi machine infinite bus system is better in terms of settling time and peak overshoot under fault conditions and provide good damping characteristics during small disturbance and large disturbances for local as well as inter area modes of oscillations [106].
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High Efficiency and Intelligent Street Lighting System using Sensors and Wireless Network

High Efficiency and Intelligent Street Lighting System using Sensors and Wireless Network

D.WIRELESS ZIGBEE NETWORK ZigBee is wireless communication technology primarily based on IEEE 802.15.4 norm for communication among multiple devices in a WPAN (Wireless Personal space Network).ZigBee is intended to be less complicated than other WPANs (such as Bluetooth) in terms of price and consumption of energy. The ZigBee Personal space Network consists of a minimum of one Coordinator, one (or more) Devices and, if necessary, of one (or more) Router. The bit rate of transmission depends on the frequency band. ZigBee transmission vary, depending on the atmospheric conditions and therefore the transmission power, ranges from tens to hundred meters since the transmission power is deliberately kept as low as necessary (in the order of few mW) to keep up very low energy consumption. In proposed system, the network is made to transfer data from the lampposts to the central station. Data is transferred purpose by purpose, from one lamppost to another one where every lamppost has a distinctive address within the system. The chosen transmission distance between the lampposts assures that in case of failure of one lamp within the chain, the signal will reach other operational lamppost while not breaking the chain. ZigBee wireless communication network has been implemented with the utilization of radio frequency modules. They operate within the ISM band at the frequency of 2.4 GHz. The receiver sensitivity is high and therefore the chance of receiving bad packets is low (about 1%). The modules ought to be provided by 3V DC supply, and then the power consumption is within the order of 50 mA. The module supports sleep mode where consumption is smaller than 10μA.
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Optimized Single Phase Solar Inverter Using Zero Voltage Switching

Optimized Single Phase Solar Inverter Using Zero Voltage Switching

The choice of the soft-switching technique, i.e., ZCS or ZVS, it is taking into account the technology of the semiconductor device that will be used. For example, the Power OSFETSs present a better performance when are commutated under ZVS, since they exhibit turn-on capacitive losses when operating in ZCS increasing the switching losses and EMI. On the other hand, the IGBTs present better results when are commutated under ZCS which can avoid their lath up and the turn-off losses caused by the tail current. Nevertheless, the ZCS techniques have some drawbacks such as, a significant voltage stress on the main diode, which increases the conduction losses, and the presence of the resonant inductor in series with the main switch, which increases the magnetic losses.
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Introduction to Scientific Computing

Introduction to Scientific Computing

Operating system support System libraries Kernel Your program Maths library Kernel Science library C library Support libraries... “Floating point” problems e.g..[r]

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Custom RMM Scripts. The Purpose Of fetching aforementioned information through PowerShell Script?

Custom RMM Scripts. The Purpose Of fetching aforementioned information through PowerShell Script?

Wake on LAN is a technology that allows a network professional to remotely power on a computer or to wake it up from sleep mode. By remotely triggering the computer to wake up and perform scheduled maintenance tasks, the technician does not have to physically visit each computer on the network.

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Grid-Connected Boost-Half-Bridge Photovoltaic Micro-inverter System Using MPPT with Fuzzy Controller

Grid-Connected Boost-Half-Bridge Photovoltaic Micro-inverter System Using MPPT with Fuzzy Controller

known P&O. In this project, a FLC for the enhancement of these MPP trackers are designed. In Perturb and observe method the controller adjusts the voltage by a small a mount fro m the array and measures power; if the power increases, further adjustments in that direction are tried until power no longer increases. This method is called as perturb and observe method and this is the most common one, although this method can result in oscillations in the power output. It is referred to as a hill climbing method [3]. In incre mental conductance method of PV, the controller measures the incremental changes in the current and voltage of the PV panel to figure out the effects of a voltage change [11]. This method requires more computation in the controller, but can track changing conditions more rapidly than the perturb and observe method (P&O) [2].
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A Unique Method of Study on Power & Loss Allocation of a Multibus Power System Employing Facts Controllers

A Unique Method of Study on Power & Loss Allocation of a Multibus Power System Employing Facts Controllers

In modern deregulated power industry different generating agencies use the same transmission lines and therefore it has become very much necessary to know the exact contribution of each generation to cater a particular load along with loss. Tracing the flow of electricity is very important to the power system engineers and designers for designing an efficient power system network. The knowledge of composition of power flow is also very useful to cost assignment [6, 8], congestion management, ancillary services and decision on scheduling of generators. The power from central sector generators is transmitted to the constitute state via transmission network erected by CTU. The constitutes are billed monthly for wheeling charges called transmission service charge, which are proportional to their total allocated share in the central sector power pool for the month. This makes the wheeling charge method approximate, in which the actual use of transmission lines are not taken into account. Therefore a proper pricing scheme is required including transmission line loss to cater a particular load by a particular generator [6].
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A Review on Power Quality Problems and its Compensating Technique in Railway Traction System

A Review on Power Quality Problems and its Compensating Technique in Railway Traction System

Abstract --- Now a days many development has done in electrified railway in world. With development power quality is become a major issue in AC electrified railway. This system has power quality problems such as harmonic current pollution, reactive power consumption, negative sequence current, and load imbalance. A large amount of negative current is injected into grid, which causes serious impact on power system, such as motor vibrations and such additional losses; reduce output ability of transformer and misoperation of protective relay. This impact intimidates railway traction supply system and power system. Therefore, it is necessary to suppress negative sequence current and harmonic current. To solve the issue of power quality in electrified railway many methods and power quality compensators are used. This paper presents why this power quality issues has been occurred in railway system, its effects and how we can comprehensively compensate this issues.
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Effect of doubly fed induction generatortidal current turbines on stability of a distribution grid under unbalanced voltage conditions

Effect of doubly fed induction generatortidal current turbines on stability of a distribution grid under unbalanced voltage conditions

Abstract: This paper analyses the effects of doubly fed induction generator (DFIG) tidal current turbines on a distribution grid under unbalanced voltage conditions of the grid. A dynamic model of an electrical power system under the unbalanced network is described in the paper, aiming to compare the system performance when connected with and without DFIG at the same location in a distribution grid. Extensive simulations of investigating the effect of DFIG tidal current turbine on stability of the distribution grid are performed, taking into account factors such as the power rating, the connection distance of the turbine and the grid voltage dip. The dynamic responses of the distribution system are examined, especially its ability to ride through fault events under unbalanced grid voltage conditions. The research has shown that DFIG tidal current turbines can provide a good damping performance and that modern DFIG tidal current power plants, equipped with power electronics and low-voltage ride-through capability, can stay connected to weak electrical grids even under the unbalanced voltage conditions, whilst not reducing system stability.
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Investigation of ship cooling system operation for improving energy efficiency

Investigation of ship cooling system operation for improving energy efficiency

The 48 energy saving is based on the concept of reducing the system operating pumps speed, and therefore, lowering the 49 required power demand for the cases where the system operates in[r]

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Smart metering in power distribution system

Smart metering in power distribution system

Nowadays, wireless sensor nodes have played significant roles in the monitoring and control system for various industrial applications to achieve automation, self-awareness and real- time control with great flexibility. The smart grid presents flexible and reliable energy distribution between the supplier control centre and the smart meters on the user-side. In addition to the main power supplier, additional energy generation sources (that may also comprise green energy) are included in smart grid, such as batteries, backup devices, plug- in hybrid electric vehicles (PHEVs), solar cells, and so forth. This aspect of the smart grid is expected to contribute to a quite complicated real-time consumer power demand management. A smart grid would help the utilities get information about the electricity use by the consumers and can potentially adapt its distribution process with respect to the time and quantum of power demand. The smart grid, which uses smart meters could potentially be used for detecting power theft. In addition, the information that the consumers would have access through the smart meters would possibly help them manage their energy use in a better and more efficient way.
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