A power transformer 4MVA/11KV/0.415Kv has been out of use in 12years. what maintenance actions/test need to be carried out before energizing.

How to calculate VCB rating for 33KV ,25 MW Power line?

can we choose current transformer secondary, to calculate residual flux in a power transformer, so as its saturation is close to the saturation level of power transformer?

how to test power transformer.YNd11

Why the power factor improvement is so important in industrial loads

QUANTUM BIOLOGY - EXAMPLE 33.8 : (a) Let ^ be the symbol of power where 1 ^ 2 = 1 x 1 = 1, 2 ^ 2 = 2 x 2 = 4. Let the number of electrons in a human body to be 10 ^ 28 = A, the number of all of the grains of sand on Earth planet to be 7 x (10 ^ 20) = B, the number of all the stars in the visible sky to be 8 x (10 ^ 3) = C. By assuming that every star in the visible sky has the same number of grains of sand as on Earth planet, prove by mathematical calculations that there are more electrons in one human body compared to the number of all of the grains of sand on the stars in the visible sky. (b) The incoming solar radiation to the Earth's surface is mainly from sun. Around 51 % of the radiation is absorbed by Earth's surface. Around 19 % is absorbed by atmosphere and clouds. In term of reflection, 4 % of the radiation is from surface of Earth, 6 % is reflected by atmosphere and the rest is reflected by clouds. Find the percentage of radiation absorbed by and reflected by biological beings on Earth, with reason for your response.

QUANTUM BIOLOGY - EXAMPLE 33.9 : (a) Let ^ be the symbol of power where 10 ^ 1 = 10, 10 ^ 2 = 100, 10 ^ 3 = 1000 etc. Total energy consumption of the brain is about 25 Watts, whereas a Blue Gene computer requires 1.5 Mega Watts. Blue Gene computer performs at 1 petaflop. In a human body, there are approximately 10 ^ 16 synapse operations per second i. e. at least 10 petaflops. Prove by calculations that a human brain is more energy efficient than a Blue Gene computer. (b) Quantum effects and quantum entanglement in the brain are identical to quantum gravity and string theory. If one is true, the other is true. What conclusion can be made if quantum effects in the brain and quantum gravity are true?

PRV (Pressure relief valve) Trip with oil splash outside power transformers

Khan,

In a power conditoining unit (inverter) of a solar plant when we measure the d.c. current fed by different strings of solar plates to inverter, the current in the negative wire is less almost by 1 ampere to the current in its positive wire say current in positive wire 5 A , then current in negative wire of the same string is 4 A. Since the current entering should be equal to current leaving then why the current is noticably less in negative wire.

Two electric lamps 40 W, 220 V each are connected in series across 220 V. What is the power consumed by the connection?

What is the difference between security constraint unit commitment and security constraint optimal power flow?

College School Exams Tests,

ACCOUNTING AND FINANCIAL ENGINEERING - EXAMPLE 34.13 : (i) In the Present Value Multiplication Rule, let PV = present value, Ra = interest rate for first discount, A = duration for first discount; Rc = interest rate for second discount, C = duration for second discount. Let PV = [ 1 / (1 + Ra) ^ A ] [ 1 / (1 + Rc) ^ C ] where ^ is the symbol of power : 3 ^ 2 = 3 x 3, 2 ^ 3 = 2 x 2 x 2. (a) For discounts involving 8 % / year for 3 years and 10 % / year for 9 years, find the value of PV. (b) If Re = interest rate for third discount, E = duration of third discount, form a mathematical equation of PV as a function of A, C, E, Ra, Rc, Re. Note : Discounts are available in the purchase of certain biochemical engineering instruments. (ii) Let R = nominal interest rate related to growth rate of money, r = real interest rate related to growth rate of purchase power. If I = inflation, where the unit of R, r and I is %, find the mathematical relatonship of r as a function of R and I.

ACCOUNTING AND FINANCIAL ENGINEERING - EXAMPLE 34.13 (CORRECTION) : (i) In the Present Value Multiplication Rule, let PV = present value, Ra = interest rate for first discount, A = duration for first discount; Rc = interest rate for second discount, C = duration for second discount. Let PV = [ 1 / (1 + Ra) ^ A ] [ 1 / (1 + Rc) ^ C ] where ^ is the symbol of power : 3 ^ 2 = 3 x 3, 2 ^ 3 = 2 x 2 x 2. (a) For discounts involving 8 % / year for 3 years and 10 % / year for 9 years, find the value of PV. (b) If Re = interest rate for third discount, E = duration of third discount, form a mathematical equation of PV as a function of A, C, E, Ra, Rc, Re. Note : Discounts are available in the purchase of certain biochemical engineering instruments. (ii) Let R = nominal interest rate related to growth rate of money, r = real interest rate related to growth rate of purchase power. If I = inflation, where the unit of R, r and I is %, find the mathematical relationship of r as a function of R and I.

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ACCOUNTING AND FINANCIAL ENGINEERING - EXAMPLE 34.15 : Based on Time Discounting of Money, let y = x / (1 + r) ^ n, where ^ = power, r = interest rate for the period in decimal value, n = number of periods, y = current value, x = future value. According to Present Value Addition Rule, the present value of a set of future payments is equal to sum for present value of each of the payments. In an engineering business, 3 future payments are to be made : $100 after 1 year; $500 after 2 years; $200 after 3 years. (a) Form an equation of y as a function of r. (b) Find the value of y in 5 decimal places if r = 8 %.