Electrical Systems
Electrical systems involve the study and application of electrical circuits, components, and devices. They encompass the flow of electric current, voltage, resistance, and power within various systems. Understanding electrical systems is crucial for analyzing and designing electronic devices, power distribution networks, and communication systems.
6 Key excerpts on "Electrical Systems"
eBook - ePub- S. Bobby Rauf(Author)
- 2020(Publication Date)
- CRC Press(Publisher)
...1 Fundamental Electrical Engineering Concepts and Principles Introduction In this first chapter of the Electrical Engineering Fundamentals text, we will explore fundamental electrical engineering terms, concepts, principles, and analytical techniques and impart knowledge that is considered elemental in the discipline of electrical engineering. Readers who invest time and effort in studying this text are likely to do so for the key purpose of gaining an introduction into the field of electricity. In this chapter, we will lay the foundations in the electrical engineering realm by covering basic electrical engineering terms, concepts, and principles, without the understanding of which, discussion and study of terms that bear important practical significance, such as power factor, real power, reactive power, apparent power, and load factor, would be untenable. Most of the material in this chapter pertains to DC, or direct current, electricity. However, some entities discussed in this chapter such as capacitive reactance, inductive reactance, and impedance are fundamentally entrenched in the AC, alternating current, realm. This text affirms that electrical engineering is rooted in the field of physics and chemistry. Physics, chemistry, and electrical engineering, as most other subject matters in science, depend on empirical proof of principles and theories. Empirical analysis and verification require tools and instruments for measurement of various parameters and entities. Hence, after gaining a better understanding of the basic electrical concepts, we will conclude this chapter with an introduction to three of the most common and basic electrical instruments, namely, multi-meter, clamp-on ammeter, and a scope meter or oscilloscope. Voltage or EMF (Electromotive Force) Voltage can be defined as a “force” that moves or pushes electrically charged particles like electrons, holes, negatively charged ions, or positively charged ions by forming an electric field...
- S. Bobby Rauf(Author)
- 2021(Publication Date)
- River Publishers(Publisher)
...Chapter 1 Electrical Engineering Basics and Direct Current Introduction In this chapter, we will explore the basics of electrical engineering terms, concepts, principles, and analytical techniques. Many readers who embark on investing time and effort in studying this text are likely to do so for the key purpose of gaining an introduction into the field of electricity. Many others, on the other hand, might be interested in refurbishing prior knowledge of electrical engineering terms, concepts, principles, and basic analytical techniques. Regardless of whether you belong to one of these two groups —or are simply in pursuit of electrical engineering at the intermediate or associate degree level — in this chapter we will lay the foundations in the electrical engineering realm by covering basic electrical engineering terms, concepts, and principles, without the understanding of which, discussion and study of terms that bear important practical significance, such as power factor, real power, reactive power, apparent power, load factor, etc. would not be feasible. Most of the material in this chapter pertains to DC, or Direct Current, electricity. However, some entities we will discuss in this chapter, such as capacitive reactance, inductive reactance, and impedance are fundamentally premised in the AC, Alternating Current, realm. Electrical engineering is largely rooted in the field of physics. Physics, and electrical engineering, as most other fields in science, depend on empirical proof of principles and theories. Empirical analysis and verification require measurement tools or instrumentation...
eBook - ePubInstrumentation
An Introduction for Students in the Speech and Hearing Sciences
- T. Newell Decker, Thomas D. Carrell(Authors)
- 2004(Publication Date)
- Psychology Press(Publisher)
...If this fundamental condition is maintained, whenever a device (load) is connected across these two outputs (no matter how distant from the source), electricity will flow through the device. WHAT IS AN ELECTRICAL CIRCUIT? As previously discussed, a closed path of electron movement is needed to have electrical energy in a useful form. This closed path is called an electrical circuit and consists of four basic elements: source, conductor, load, and switch. 1. Source. The original source is some electrical generator, but for practical purposes the source may be thought of as the wall outlet. 2. Conductor. Conductors are wires that carry the electrical current to the load that will use it. Conductors offer little resistance to the flow of current because the metals they are made of are rich in a supply of free electrons. 3. Load. The load is any device that uses the electrical current. The load, unlike the conductor, offers resistance to the flow of the current. 4. Switch. This unit in the system provides a method for controlling the energy. A switch controls current flow by placing a very high resistance (air gap) in the way of the current flow when the switch is opened. When the switch is closed, the resistance is removed. Electrical circuits can be classified as either series circuits or parallel circuits. The simple diagram in Fig. 1.10 shows two batteries connected in parallel (Fig. 1.10 a) and in series (Fig. 1.10 b). In the case of the parallel connection the total voltage is 1.5 volts. However, in the series circuit the total is three FIG. 1.10. Series and Parallel circuits. volts. Series and parallel circuits also alter the total values of resistors, capacitors, and inductors in a circuit. OPEN CIRCUITS AND SHORT CIRCUITS An open circuit is a fault, intentional or otherwise, that disrupts the flow of current in the conductor...
eBook - ePubElectrical Engineering
Fundamentals
- Viktor Hacker, Christof Sumereder(Authors)
- 2020(Publication Date)
- De Gruyter Oldenbourg(Publisher)
...1 The basic physic principles and definitions 1.1 The simple circuit In everyday life, people do not distinguish between technically correct designations for electric quantities but abbreviate and incorrectly name it “electricity”. Colloquially, the expression “electricity bill” is used, when in reality the electrical energy consumption is meant; when an electrical accident happens, it is referred to as “electric shock”. A person with technical knowledge is aware that a flow of an electric charge is designated “electric current” and that the physical quantity of current (intensity) uses the unit ampere. Furthermore, an expert knows that it is the voltage (measured in volts) that drives the current and that resistance (measured in ohm) at constant voltage determines the current (Figure 1.1). To better understand the correlation between electric current, voltage and resistance, we look at the water cycle as analogue to the electric circuit. Figure 1.1: Correlation between current, voltage and resistance. Table 1.1: Water cycle as analogue to electric circuit. Water cycle (analogue) Electric circuit Figure 1.2: Closed water cycle. Figure 1.3: Closed circuit. The flow of water Q t is caused by the pressure difference Δ P generated by pump P. The current flow is caused by the potential difference (= voltage V) generated by the voltage source. The pressure difference Δ P determines the amount of water pumped via the load per time. The potential difference (voltage V) determines the electric charge per time (current I) flowing through the load. The pressure loss due to the resistance in the container C is as high as the pressure...
eBook - ePubElectrical Energy Systems
Second Edition
- Mohamed E. El-Hawary(Author)
- 2018(Publication Date)
- CRC Press(Publisher)
...Chapter 2 BASICS OF ELECTRIC ENERGY SYSTEM THEORY 2.1 Introduction This chapter lays the groundwork for the study of electric energy systems. We develop some basic tools involving fundamental concepts, definitions, and procedures. The chapter can be considered as simply a review of topics utilized throughout this work. We start by introducing the principal electrical quantities. 2.2 Concepts of Power in Alternating Current Systems Generally, the electric power systems specialist is more concerned with electric power in the circuit rather than the currents. The value of instantaneous power flowing into an element is the product of voltage across and current through it. It seems, then, reasonable to exchange the current for power without losing any information. In treating sinusoidal steady-state behavior of circuits, some further definitions are necessary. To illustrate the concepts, we use a cosine representation of the waveforms. Consider the impedance element Z = Z ∠ ϕ. For a sinusoidal voltage, v (t) given by υ (t) = V m cos ω t The instantaneous current in the circuit is i (t) = I m cos (ω t − ϕ) Here I m = V m / | Z | The instantaneous power into the element is given by p (t) = υ (t) i (t) = V m I m [ cos (ω t) cos (ω t − ϕ) ] This reduces. to p (t) = V m I m 2 [ cos ϕ + cos (2 ω t − ϕ) ] Since the average of cos (2 ωt - ϕ) is zero, through 1 cycle, this term therefore contributes nothing to the average of p, and the average power p av is given by p a v = V m I m 2 cos ϕ (2.1) Using the effective (rms) values of voltage and current and substituting V m = 2 (V rms), and I m = 2 (I rms), we. get p a v = V r m s I r m s cos ϕ (2.2) The power entering any network is the product of the effective values of terminal voltage and current and the cosine of the phase angle ϕ, which is, called the power factor (PF). This applies to sinusoidal voltages and currents only...
eBook - ePubShort-Circuits in AC and DC Systems
ANSI, IEEE, and IEC Standards
- J. C. Das(Author)
- 2017(Publication Date)
- CRC Press(Publisher)
...Yet, the power system designs may fall short from engineering design and safety considerations. Even the functionality for which these systems are designed for adequate performance may be compromised. Though there is a spate of guidelines and standards, it is not unusual to see inadequately designed systems, lacking in some respect or the other. Competition and economical constraints can make even expert designers and planners to cut corners, which may ultimately result in spending more funds for the short-term fixes and long-term upgrades. The power system studies can be an effective tool in the design of power systems. These can also identify weak spots, limitations of the current systems, and point to remedial measures. For example, The switching devices may be underrated from short-circuit conditions. The load flow may indicate problems of voltage drops or voltage instability under certain operating and switching conditions. The protective relaying may be inadequate; lack of coordination may result in nuisance trips and shutdowns. The harmonic pollutions may overload the system components and application of capacitors may result in harmonic resonance problems. The harmonics can seriously derate the cables and transformers and overload the rotating equipment. Adequate surge protection may not be provided. Considerations may not be applied for transient stability for disturbances and faults in the system. The equipment may be underrated to carry the system load currents in one condition or the other. This series attempts to analyze these problems. The surge protection is not discussed in this series. 1.9 Electrical Standards and Codes There are a number of current standards and guidelines for planning and designing of electrical power systems for commercial, industrial, and utility applications...
