Section 11 AC Power Analysis

Presentation Transcript

Section 11 AC Power Analysis Chapter Objectives: Know the contrast between prompt power and normal power Learn the AC rendition of most extreme power exchange hypothesis Learn about the ideas of viable or Rms esteem Learn about the unpredictable power, obvious power and power figure Understand the standard of protection of AC power Learn about power consider rectification Huseyin Bilgekul Eeng224 Circuit Theory II Department of Electrical and Electronic Engineering Eastern Mediterranean University

An Electical Power Distribution Center

Apparent Power and Power Factor The A verage Power relies on upon the Rms estimation of voltage and current and the stage edge between them . The Apparent Power is the result of the Rms estimation of voltage and current. It is measured in Volt amperes ( VA ). The Power Factor (pf) is the cosine of the stage distinction amongst voltage and current. It is additionally the cosine of the point of load impedance. The power variable may likewise be viewed as the proportion of the genuine power scattered to the clear force of the heap.

Apparent Power and Power Factor Not all the obvious power is devoured if the circuit is incompletely receptive .

Power hardware are appraised utilizing their appparent control in KVA.

Apparent Power and Power Factor Both have same P Apparent Powers and pf 's are distinctive Generator of the second load is over-burden

Apparent Power and Power Factor Overloading of the generator of the second load is kept away from by applying power consider redress.

Complex Power The COMPLEX Power S contains all the data relating to the power consumed by a given load.

Complex Power The REAL Power is the main helpful power conveyed to the heap. The REACTIVE Power speaks to the vitality trade between the source and responsive piece of the heap. It is being exchanged forward and backward between the heap and the source The unit of Q is volt-ampere receptive (VAR)

Resistive Circuit and Real Power

Inductive Circuit and Reactive Power

If the normal power is zero, and the vitality provided is returned inside one cycle, why is a responsive force of any centrality? At each moment of time along the power bend that the bend is over the hub (positive), vitality must be provided to the inductor, despite the fact that it will be returned amid the negative segment of the cycle. This power necessity amid the positive part of the cycle requires that the producing plant give this vitality amid that interim, despite the fact that this power is not disseminated but rather just "acquired." The expanded power request amid these interims is a cost element that should that must be passed on to the mechanical customer. Most bigger clients of electrical vitality pay for the obvious power request instead of the watts scattered since the volt-amperes utilized are delicate to the receptive power prerequisite. The nearer the power component of a modern purchaser is to 1, the more productive is the plant's operation since it is restricting its utilization of "acquired" power. Inductive Circuit and Reactive Power

Capacitive Circuit and Reactive Power

Complex Power The COMPLEX Power contains all the data relating to the power consumed by a given load. Genuine Power is the real power scattered by the heap. Responsive Power is a measure of the vitality trade amongst source and receptive piece of the heap.

Power Triangle a) Power Triangle b) Impedance Triangle Power Triangle The COMPLEX Power is spoken to by the POWER TRIANGLE like IMPEDANCE TRIANGLE. Control triangle has four things: P, Q, S and θ .

Power Triangle F inding the aggregate COMPLEX Power of the three burdens.

Power Triangle

Real and Reactive Power Formulation

Real and Reactive Power Formulation

Real and Reactive Power Formulation

Real and Reactive Power Formulation P is the REAL AVERAGE POWER Q is the most extreme estimation of the circling power streaming back and forward

Real and Reactive Powers REAL POWER CIRCULATING POWER

Real and Reactive Powers V rms =100 V I rms =1 An Apparent power = V rms I rms =100 VA From p ( t ) bend, watch that power streams from the supply into the heap for the whole span of the cycle! Likewise, the normal power conveyed to the heap is 100 W. No Reactive power.

Real and Reactive Powers Power Flowing Back V rms =100 V I rms =1 An Apparent power = V rms I rms =100 VA From p ( t ) bend, control streams from the supply into the heap for just a piece of the cycle! For a bit of the cycle, control really streams back to the source from the heap! Likewise, the normal power conveyed to the heap is 50 W! In this way, the helpful power is not exactly in Case 1! There is responsive power in the circuit.

Practice Problem 11.13: The 60  resistor ingests 240 Watt of normal power. Ascertain V and the mind boggling force of each branch. What is the aggregate complex power?

Practice Problem 11.13: The 60  resistor retains 240 Watt of normal power. Compute V and the perplexing force of each branch. What is the aggregate complex power?

Practice Problem 11.14: Two burdens are associated in parallel. Stack 1 has 2 kW, pf=0.75 driving and Load 2 has 4 kW, pf=0.95 slacking. Compute the pf of two burdens and the intricate power provided by the source. Stack 1 2 kW Pf =0.75 Leading LOAD 2 4 kW Pf =0.95 Lagging

Conservation of AC Power For parallel association: The mind boggling, genuine and receptive force of the sources meet the particular aggregate of the unpredictable, genuine and responsive force of the individual burdens. b) Loads in Series a) Loads in Parallel S ame results can be acquired for an arrangement association .

Complex power is Conserved