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The Buchholz Relay is a gas-actuated protection relay. It is a mechanical relay. All oil-immersed transformers that have a conservator tank should be equipped with a Buchholz relay. A Buchholz relay can detect both slow-developing faults and major transient faults occurring within the transformer. It provides an early warning (alarm) for slow-developing faults and initiates … Read more
Location of Capacitor Banks It is always desirable to connect a capacitor bank as close as possible to the load. This optimizes the use of the capacitor bank. Whenever we connect a load to the power system, the capacitor associated with that load also becomes connected to the system. The capacitor cancels out the reactive … Read more
Let us have a detailed discussion on the Quality Factor and Dissipation Factor. We also call these two factors the Q factor and the D Factor. What is Quality Factor or Q Factor? The Quality Factor, or Q factor, is the dimensionless parameter that describes the efficiency and sharpness of the reactive components. The reactive … Read more
An LCR meter is an advanced measuring instrument. We use it to measure the inductance (L), capacitance (C), and resistance (R) of a circuit. It helps determine the precise values of capacitances, inductances and resistances. These are the three basic parameters of an electrical or electronics circuit. It can measure the three circuit parameters: inductance … Read more
Requirement of Capacitor Banks Let us first discuss the actual requirement of capacitor bank in the power system. Actually, inductive loads such as transformers, motors, reactors, transmission networks, etc., cause current to lag behind the voltage. This increases the phase angle between current and voltage which in turn reduces the cosine of that angle. The … Read more
Why do we use capacitor banks in the system? Generally, these capacitor banks are connected in 33 kV systems. Normally, in a 33 kV system, we use a double star ungrounded capacitor bank. Before discussing the actual connection configuration of a double star ungrounded capacitor bank, let us recall the benefits of a capacitor bank in a … Read more
Capacitor Elements A capacitor element forms the basic building block of a capacitor unit. It has two metal electrodes. A dielectric medium separates these electrodes. Engineers connect multiple elements in series or parallel to form a capacitor unit’s internal circuit. They join several units in series to match the system’s rated voltage. The required MVAR … Read more
Capacitor Element Winding In the winding process, the material is wound using aluminum foil and polypropylene (PP). First, a layer of PP is placed, followed by a layer of aluminum foil. This layering continues step by step until the complete element is formed. Once the winding is complete, the element is tested on the spot … Read more
In substations, we always see some reactors connected in series with the capacitor bank. First, a circuit breaker along with an isolator connects the capacitor bank to the system bay. After the capacitor bank, a reactor comes in series with each branch of every phase of the capacitor. Understanding the Inrush Current Now, the question … Read more
Normally, most of the utilities use double star ungrounded neutral capacitor banks. They connect series and parallel capacitor units to form that double star design. They normally use it in 33KV systems of electrical power substations. Before going to the detail protection scheme of double star ungrounded 3-phase capacitor bank, we may recall the connection … Read more