What is an AC Power Supply?
Alternating Current (AC) power supplies generate power to a load with programmable voltage, phase, and frequency for testing purposes. Essential for measurement of current in electrical systems applications.
Equipment designed to use AC typically requires more voltage than their DC counterparts to ensure consistency.
The two AC power supply types are:
- Regulated AC: no alternating design options, but constant supply to the load.
- Unregulated AC: allows for alternating design but no constant supply to load.
AC power supplies can be used to change the voltage and frequency.
AC power sources are commonplace in the industrial and scientific sectors, often as lab instruments for compliance testing. They are either single-phase or three-phase units with varying input and output powers. Most conform to industry standards such as DO-160, MIL-STD-704, and IEC 61000-4-11.
Usually, an AC power supply receives the voltage from a wall outlet (mains supply), using a transformer to regulate the voltage (either up or down), in order to attain the desired voltage, as well as to allow a certain degree of filtering to occur.
Note: In some cases, an AC Power Supply serves as an isolation transformer, where the source voltage and the output voltage come from the same source.
Types and Uses
- Autotransformers: Providing main isolation.
- Variac: A variable output autotransformer.
- AC suppliers designed to provide a nearly constant current.
- Power conversion: Not using a transformer
- Portable AC Power, which may be provided by whose current is passed to a regulator circuit to provide a constant voltage at the output.
- Line Conditioner: When the output voltage and input voltage are the same.
- Uninterruptable Power Supply; in cases where the device is designed to provide backup power.
It is noteworthy that a circuit may be designed with a voltage multiplier topology to directly step-up AC power; formerly, such an application was a vacuum tube AC/DC receiver.
- In modern use, AC power supplies can be divided into single phase and three phase “The primary difference between single phase and three phase AC power is the constancy of delivery.” [3] AC power Supplies can also be used to change the frequency as well as the voltage, they are often used by manufacturers to check the suitability of their products for use in other countries. 230 V 50 Hz or 115 60 Hz or even 400 Hz for avionics testing.
Examples for AC Power Supply Applications.
It is noteworthy that output voltage may vary, depending on impedance of the load
- An automobile storage battery; the power source provides a direct current.
- An inverter and step-up transformer; convert the power source into AC power.
- At a construction site, in an automobile or a boat, a backup power generation for emergency services; an inverter and a step-up transformer may be used.
Getting to the Specifics: What Are Grid Simulators?
Power electronic devices that emulate AC electrical grids in both normal (voltage, frequency, phase angle) and disturbed conditions (voltage dips, frequency, voltage fluctuations, flicker).
It is a rather powerful equipment, designated to generate voltage sources and set up different types of grids facilitating the assessment of all scenario types.
Thanks to the flexibility of the concerned equipment, CINERGIA’s Grid Simulators are widely used in the field of renewable energies for the purpose of testing generators connected to the grid and their compliance with grid codes.
