Contents

- 1 How the power factor can be improved?
- 2 What is the power factor of a synchronous motor?
- 3 What causes poor power factor?
- 4 What is a good power factor?
- 5 Why DC is used for excitation?
- 6 What is synchronous speed?
- 7 How does excitation affect power factor?
- 8 What is poor power factor?
- 9 What happens when power factor 0?
- 10 What does a PF of 80% mean?
- 11 Can power factor be more than 1?
- 12 How can we reduce the power factor?
- 13 What is standard power factor?

## How the power factor can be improved?

Improving the PF can maximize current-carrying capacity, improve voltage to equipment, reduce power losses, and lower electric bills. The simplest way to improve power factor is to add PF correction capacitors to the electrical system. PF correction capacitors act as reactive current generators.

## What is the power factor of a synchronous motor?

The usual synchronous motor power factors are unity (1.0) or 0.8 leading. Values of 0.7 or 0.6 leading will give more leading correction to an otherwise lagging system.

## What causes poor power factor?

The usual reason for the low power factor is because of the inductive load. The important inductive loads responsible for the low power factor are the three-phase induction motors (which operate at a 0.8 lagging power factor ), transformer, lamps and welding equipment operate at low lagging power factors.

## What is a good power factor?

The ideal power factor is unity, or one. Anything less than one means that extra power is required to achieve the actual task at hand. All current flow causes losses both in the supply and distribution system. A load with a power factor of 1.0 results in the most efficient loading of the supply.

## Why DC is used for excitation?

In the alternator, as the rotor conductor changes its position as the rotor rotating so constant flux is to be produced in the rotor winding and it is possible only when the DC supply is given to the rotor winding. As we need constant flux that is why DC is used instead of AC for excitation of Synchronous Alternator.

## What is synchronous speed?

Synchronous speed is a significant parameter for the rotating magnetic field-type AC motor. It is determined by the frequency and the number of magnetic poles. Synchronous speed No = [rps, revolutions per second] f = Frequency [Hz] p = Number of magnetic poles.

## How does excitation affect power factor?

A change in the excitation, thus, affects only the power factor of its output. This reduces the terminal voltage slightly, so let the excitation of the first alternator be increased so as to bring the terminal voltage back to its original value.

## What is poor power factor?

The major effect of poor power factor is higher value of line current. We know that power factor (pf) is an important parameter for calculation of power in an AC circuit. This means that a poor power factor i.e. low power factor will result in higher load current and hence higher losses.

## What happens when power factor 0?

When power factor is equal to 0, the energy flow is entirely reactive and stored energy in the load returns to the source on each cycle. When the power factor is 1, all the energy supplied by the source is consumed by the load.

## What does a PF of 80% mean?

To find the PF, divide 100 kW by 125 kVA to yield a PF of 80 %. This means that only 80 % of the incoming current does useful work and 20% is wasted through heating up the conductors. Improving the PF can maximize current-carrying capacity, improve voltage to equipment, reduce power losses, and lower electric bills.

## Can power factor be more than 1?

Since power factor is a cosine function of the relative phase angle between current and voltage there are no possible values greater than one. A power factor of one is achieved when the voltage and current are in phase and there’s no reactive power.

## How can we reduce the power factor?

Correcting Your Power Factor Minimize operation of idling or lightly loaded motors. Avoid operation of equipment above its rated voltage. Replace standard motors as they burn out with energy-efficient motors. Even with energy-efficient motors, however, the power factor is significantly affected by variations in load.

## What is standard power factor?

In AC circuits, the power factor is the ratio of the real power that is used to do work and the apparent power that is supplied to the circuit. The power factor can get values in the range from 0 to 1. When all the power is reactive power with no real power (usually inductive load) – the power factor is 0.