WHAT IS POWER QUALITY ALL ABOUT? BASIC INFORMATION on Jan 30, 2014 in Power Quality Electric power quality has emerged as a major area of electric power engineering. The predominant reason for this emergence is the increase in sensitivity of end-use equipment. The various aspects of power quality as it impacts utility companies and...
FLICKERING LIGHTS – POWER QUALITY CASE STUDY AND SOLUTION on Aug 3, 2012 in Power Quality Flicker PQ Case Study This case study concerns a residential electrical system. The homeowners were experiencing light flicker when loads were energized and deenergized in their homes. Background Residential systems are served from single-phase transformers employing...
FERRORESONANCE – POWER QUALITY ISSUE BASIC AND TUTORIALS on Aug 3, 2012 in Power Quality The term ferroresonance refers to a resonance that involves capacitance and iron-core inductance. The most common condition in which it causes disturbances in the power system is when the magnetizing impedance of a transformer is placed in series wit...
MITIGATION EQUIPMENT FOR VOLTAGE SAGS POWER QUALITY PROBLEM on Aug 3, 2012 in Power Quality The most commonly applied method of mitigation is the installation of additional equipment at the system-equipment interface. Also recent developments point toward a continued interest in this way of mitigation. The popularity of mitigation equ...
NEC GROUNDING TERMS AND DEFINITIONS BASIC INFORMATION on Aug 3, 2012 in Grounding Bonding Jumper, Main: The connector between the grounded circuit conductor (neutral) and the equipment-grounding conductor at the service entrance. Conduit=Enclosure Bond: (bonding definition) The permanent joining of metallic parts to form an el...
LOW SIDE SURGES BASIC INFORMATION AND TUTORIALS on Aug 3, 2012 in Surges Some utility and end-user problems with lightning impulses are closely related. One of the most significant ones is called the low-side surge problem by many utility engineers. The name was coined by distribution transformer designers because i...
HARMONICS IN ROTATING MACHINES AND ARC FURNACE BASICS AND TUTORIALS on Jul 28, 2012 in Harmonics HARMONICS IN ROTATING MACHINES The distribution of the armature windings and the presence of slots in the machines cause spatial harmonics in them. These in turn produce time harmonics in the induced voltages, which appear at the terminals. Most of...
UNDESIRABLE EFFECTS OF THE HARMONICS (POWER SYSTEM) BASIC INFORMATION on Jul 28, 2012 in Harmonics Different categories of harmonic-producing loads are supplied by the electric utilities such as 1. Domestic loads like fluorescent lamps, light dimmers, etc. 2. Ripple control systems for regulating hot-water loads 3. Medium-sized industrial loads...
HARMONICS IN POWER TRANSFORMERS BASIC INFORMATION AND TUTORIALS on Jul 28, 2012 in Harmonics Transformers HARMONICS IN NO-LOAD EXCITING CURRENT Because transformer cores are made of ferromagnetic materials, the exciting current of the transformer under no-load conditions is not sinusoidal even though the applied voltage and flux are sinusoidal due to the...
INFLUENCE OF FREQUENCY VARIATIONS ON PARALLEL CONNECTED CONDENSERS AND COILS on Jul 28, 2012 in Frequency Variation Until now, the use of the some control diagram was only possible for motors fed from a low-voltage network due to the lack of technical and economic solutions acceptable for the medium-voltage zone. Currently, these solutions exist, and therefore th...
