Short-Circuit Currents are currents that introduce large amounts of destructive energy in the forms of heat and magnetic force into a power system. The reliability and safety of electric power distribution systems depend on accurate and thorough knowledge of short-circuit fault currents that can be present, and on the ability of protective devices to satisfactorily interrupt these currents. VB Engineering is a Detailed Engineering Consultants provides services like Short Circuit Analysis, Harmonic Analysis, Protective Device Coordination and Arc Flash Study.
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Short-Circuit Currents are currents that introduce large amounts of destructive….Continue reading about Short Circuit Analysis and Arc Flash Studies..
Arc Flash Protection - The NFPA 70E Standard and OSHA Regulations have been established to protect workers from electrical shock and arc flash hazards and to educate workers about the protection needed from these dangers. The NFPA 70E Standard specifies areas within which arc flash protection is required for workers involved in the maintenance of energized or potentially energized electrical equipment. All personnel within the defined boundaries must wear specified protective equipment. The NFPA 70E Standard and OSHA Regulations must be met, and arcflash-ppe will help to make it easy to meet them. To ease the burden of meeting all the necessary safety standards and requirements Salisbury has developed convenient Personal Protective Equipment Kits. All the Arc and Shock Protection PPE Kits meet the safety standards categorized by the Hazard Risk Category for each job.
Harmonic analysis is a diverse field including such branches as Fourier series, isospectral manifolds and topological groups.The total harmonic distortion, or THD, of a signal is a measurement of the harmonic distortion present and is defined as the ratio of the sum of the powers of all harmonic components to the power of the fundamental frequency. Based on the IEEE-519 standards,the IEEE is the Institute of Electrical and Electronics Engineers. IEEE 519, “Recommended Practices and Requirements for Harmonic Control in Electric Power Systems,” was published in 1981. The document established levels of voltage distortion acceptable to the distribution system.The Harmonic currents are caused by the equipment comprising power electronics circuits that are typical non-linear loads and generate harmonic currents. Such loads are increasingly frequent in all industrial, commercial and residential installations and their percentage in overall electrical consumption is growing steadily.
Infrared thermography or Thermal Imaging Inspection is equipment or method, which detects infrared energy emitted from object, converts in to temperature, it displays image of temperature distribution.the equipment is called infrared thermograph and the method to be called as infrared thermography. Recently, however, more and more public literatures show tendency not to pay attention to such appellative. We call our equipment infrared thermography. It captures as a temperature distribution on a surface,and it can display as a visible information. Temperature can be measured from a distance without contacting an object. Temperature can be measured in real time.Relative comparison of distribution of surface temperature can be made over a wide area.Temperature can be measured easily for a moving object or an object which is dangerous to get close to.
In any power system network, protection should be designed such that protective relays isolate the faulted portion of the network at the earliest, to prevent equipment damage, injury to operators and to ensure minimum system disruption enabling continuity of service. When relays meant to protect specific equipments, transmission/distribution lines/feeders or primary zone protective relays, do not operate and clear the fault in their primary protection zone, backup relays located in the backup zone, must operate to isolate the fault, after providing sufficient time discrimination for the operation of the primary zone relays. The term or phrase relay coordination, therefore covers the concept of discrimination, Selectivity and backup protection as explained in the foregoing discussion. The coordination is not confined only to relays and equipment operating characteristics, but also includes other protective device characteristics such as Fuse, MCB’s, Circuit Breakers as applicable.
Design for lean manufacturing is a process for applying lean concepts to the design phase of a system, such as a complex product or process. The term describes methods of design in lean manufacturing companies as part of the study of Japanese industry.”Lean Design”, design for lean manufacturing builds on the set of principles that emerged from design for the customer value and design for manufacturability. Since some lean tools are used in the practice of design for lean manufacturing, it borrows the first word in its name from lean manufacturing as exemplified by the Toyota Production System.Design for lean manufacturing was first coined by Womack, Jones, and Roos after studying the differences between conventional development at American automotive companies and lean methods at Japanese automobile producers. While lean manufacturing focuses on optimization of the production stream and removal of wastes once the value stream has been created, Lean Design concerns itself with methods and techniques to create a lean solution from the start, resulting in more value and fewer wastes across the value stream.Lean design seeks to optimize the development process through rapid learning cycles to build and test multiple concepts early.Managing the knowledge value stream, systematic problem solving with analysis of the trade-offs between various design options,and solutions generated from ideas filtered by systematic innovation methods are viewed as methods within the lean design process.
Solar PV power plants are designed to maximize the plant performance and provide owners with a rapid return on investment and long plant operating life. Optimized standard concepts for each stage of the PV power plant process and a complete capability in design, engineering, and commissioning. The array of a photovoltaic power system, or PV system, produces direct current (DC) power which fluctuates with the sunlight’s intensity. For practical use this usually requires conversion to certain desired voltages or alternating current (AC), through the use of inverters. Multiple solar cells are connected inside modules. Modules are wired together to form arrays, then tied to an inverter, which produces power at the desired voltage, and for AC, the desired frequency/phase. Many residential PV systems are connected to the grid wherever available, especially in developed countries with large markets. In these grid-connected PV systems, use of energy storage is optional. In certain applications such as satellites, lighthouses, or in developing countries, batteries or additional power generators are often added as back-ups. Such stand-alone power systems permit operations at night and at other times of limited sunlight.
Electrical earthing systems are designed for applications operating at relatively low frequencies, and those have driven the use of increasingly sophisticated technology, including specialist software, to determine ground resistivity, improve design and measure system performance. depending upon the requirements of their equipment. For sensitive equipment and under extreme circumstances, a one ohm specification may sometimes be required. When designing a ground system, the difficulty and costs increase exponentially as the target resistance-to-ground approaches the unobtainable goal of zero ohms.
Purpose of ieee 1584, IEEE 1584-2002 was developed to help protect people from arc-flash hazard dangers. The predicted arc current and incident energy are used in selecting appropriate overcurrent protective devices and personal protective equipment (generally abbreviated as PPE), as well as defining safe working distance. Since the magnitude of the arc current is inherently linked with the degree of arc hazard, the arc is examined as a circuit parameter. Furthermore, since estimations are often useful, simple equations for predicting ballpark arc current, arc power, and incident energy values and probable ranges are presented in this work. Arc Flash Hazard calculations are currently implemented in most of the industry plants due to OSHA regulations. The IEEE 1584 empirically derived model accurately accounts for a wide variety of setup parameters including: Voltages in the range of 208 V–15 000 V, three-phase. Frequencies of 50 Hz or 60 Hz. Bolted fault current in the range of 700 A – 106,000 A. Grounding of all types and ungrounded.
FlexSim is a discrete event manufacturing simulation software developed by FlexSim Software Products, Inc. The FlexSim family currently includes the basic FlexSim simulation software and FlexSim Healthcare Simulation (FlexSim HC) As general purpose simulation software, FlexSim is used in a number of fields: Manufacturing - Production assemble line, Logistics and distribution - Container terminal operation, supply chain design, distribution center work flow, service and storage layout, etc. Transportation - Highway system traffic flow, transit station pedestrian flow, maritime vessel coordination, custom traffic congestion, etc. Others - Oil field or mining process, networking data flow etc.