The best operating condition of any process/equipment can be only observed by analyzing all those parameters that influence efficiency. One of these is power - every piece of process/equipment needs power to operate and hence power consumption and power quality measurements become an integral part of design and test of the process/equipment. But how do you measure this? What are the methods and instruments that can be used? How do these instruments work? This article shall discuss and answer all these questions.

What is power?

Let's go back to the basic level. Electrical power is basically the rate at which an electrical equipment or machine consumes energy. It is the amount of electrical energy transferred within an electrical circuit per unit time. The unit for the measurement in the SI is watt (W). Other standard units of measure are the kilowatt (kW), megawatt (MW), and milliwatt (mW). Also appropriate is to make a distinction between the terms power and energy. Terms that are not interchangeable, power is the ability or capacity to use electrical energy; energy expresses the flow of the same in time. Why the power analysis? First, let's understand why power needs to be measured. As the famous management consultant Peter Drucker once remarked, "If you can't measure it, you can't manage it.". It is very important to keep track of all the parameters that can affect your equipment. This has to be done with high accuracy, and more importantly, electrical power has to be utilized to the highest efficiency possible to ensure the equipment functions properly and has a long life. This will make the operation smooth, efficient, and safe. Loss in the equipment is reduced too, which makes it last longer. Having information on the power needs allows us, in the future, to enhance the performance of pieces of equipment and services, ensure that parameters conform to those put in place by the government, and gradually reduce costs and time consumption. This, in turn, reduces environmental pollution. Power analyzers are designed for just this reason: to make all these complex processes easy with only a few operations by the user.

How does one measure power?

The measurement of power is different in a different type of supply. It includes true power, popularly known as real power or active power for DC circuits. In case of AC systems, the measurement includes apparent power, active power and reactive power. Calculations in power consumption per complete cycle are done accordingly .

What is Wattmeter?

It is essentially an apparatus employed in measuring the active power taken out by a circuit when subjected to voltage input and current drawn. One current coil and one potential coil are the basic elements of a wattmeter. It works on the principle of electromagnetic induction. This multiplication of instantaneous current and instantaneous voltage can be calculated using devices such as a wattmeter, which is then integrated over one cycle time period, thereby giving true power measurements for any waveform. Inputs of Wattmeter's Wattmeter's have four terminals. Two terminals for voltage input and two terminals for current input (which come from CT output or, if the current is 5A or less, directly from line wires). Types of power analyzer Depending on what system they would be most suitable for, wattmeter's can be classified as: Single-phase power meter (two-wire system) two-phase power meter (three-wire system) three-phase power meter (four-wire system) three-phase power meter (three-wire system) Three-phase, three-wire system In two wattmeter power measurement method, voltage across two phases and respective currents are given to two wattmeter's, keeping any one phase common. Three-phase four-wire system In the R, Y, B phase and Neutral system voltage across the neutral of each phase is measured algebraic multiplication is done with respective phase currents. Total system power is obtained as summation of three-phase readings.

Power Meters

The proper selection of the power meter is very instrumental in protecting your expensive equipment. You will need a device that will pre-emptively warn you about overcurrent or overvoltage power factor of each phase and, if possible, voltage and current harmonics levels scenarios. If not correctly done, it might lead to electrical fires and permanent damage to your equipment. Dolphin Automation offers a few power meters to perfectly suit a variety of complex systems. Long life with low maintenance and a clear interface these devices are highly user-friendly and convenient to operate. They are available in several sizes with an ultra-bright LED display, elegant appearance, and a universal auxiliary supply. Site programmable CT and PT ratio available.

Frequently Asked Questions

What is power system analysis?

A power system analysis examines and studies many aspects of a network system, be it generation, relaying, or supply of electricity. These are conducted to make sure the networks are safe, reliable, and in perfect working condition.

What are some power measurement devices?

Examples of power measurement devices include voltmeter, ammeter, wattmeter's, power analyzers, power meters, and power transducers.

What are some different ways of measuring electrical power?

The electrical power measurement technique is selected based on the type of input current supply. If it receives a DC supply, voltage and current are measured directly by voltmeter and ammeter respectively and used in the calculation of the power (P=V*I). In case of single-phase AC as input, wattmeter's is used for measuring the effective power. In case of three-phase AC supply, the total effective power is measured using three-phase wattmeter's.

What is the purpose of power fault analysis?

The fault analysis has an important role in finding faults that may lead to failures and damage. Even exceeding the specified range of voltage or current can be fatal. The fault analysis will provide the need to interpret actions to be performed which become necessary for system stability.