The Omniverter DIGIT@L is an automatic voltage regulator (AVR) that automatically adjusts the voltage level to keep the voltage constant. It is commonly used in areas with a weak electrical grid.
A weak electrical grid can cause a variety of issues, including power outages, voltage fluctuations, and brownouts. Voltage fluctuations can also cause damage to appliances and equipment.
The three-phase DIGIT@L line of voltage stabilizers is based on columnar voltage regulators and covers the range from 200kVA to 6000kVA. All models have a robust construction suitable for industrial applications and allow for a choice of several input voltage variation percentages within a broad range (from +30% up to -45%).
The AVR ensures that the voltage level remains within a specific range, providing a stable power supply for equipment and devices connected to the network.
The control circuit of DIGIT@L compares the actual output voltage to the predefined voltage setting. If the percentage deviation is excessive, the control circuit activates the voltage regulator gear motor, which adjusts the position of the regulator rollers, changing the voltage drawn and supplied to the primary winding of the buck/boost transformer.
The secondary voltage of the buck/boost transformer will be in phase with or opposing the supply voltage, allowing the voltage from the regulator to be either added to or subtracted from the main voltage, compensating for any variations.
Voltage magnitude variation is either overvoltage or undervoltage. Utilities typically regulate the voltage levels by using transformers with tap changers.
However, automatic tap changers are not always available to regulate the voltage magnitude which can impact the regulation levels as the load change.
Long electrical lines and overloaded transformers or generators can cause unacceptable variation in voltage magnitude. Voltage unbalance can damage to electrical equipment.
Overvoltage is defined by the IEEE 1159 as an increase in the AC voltage (RMS), typically to 110% - 120% of nominal, for duration longer than 1-minute.
Undervoltage is described by IEEE 1159 as the decrease in the AC voltage (RMS), typically to 80% - 90% of nominal, for duration longer than 1-minute.
Equipment must operate satisfactorily within the -10% to +10% voltage variation of the distribution utility's nominal service voltage.
Voltage fluctuations degrade the performance of electrical equipment. Undervoltage variation increases current and cause overheating, malfunction, premature failure or completed failure of equipment.
Overvoltage variation decreases current flow that reduces efficiency. Circuit boards are designed to operate within a specified voltage range, so overvoltage could cause premature failure of these components.