AVE - Automatic voltage equalizer

 AVE – Automatic Voltage Equalizer

The AVE is our most advanced unit and it is based on EM Energy Solutions` revolutionary technology of using electromagnetism to balance and optimize the distribution system at the speed of the current.

AVE is designed for optimal phase to ground voltage control. With the use of motor controlled variable isolation transformers, accurate control of individual phase voltage is possible. The unit
can balance voltage imbalances close to 100%
(fault condition) to nearly zero percent imbalance.

The AVE have a state of the art power quality meter, which will give the operator detailed status of the network quality and trigger events. Operational status and network information can
be obtained locally from the HMI panel and from a remote web interface. A cloud solution is also possible so you can access and monitor your system in real time from anywhere in the world.

AVE`s main components are the three state of the art single phased auto variable transformers, designed in cooperation with Metrel.

The unit uses its powerful computer to constantly log and gather important data from a wide range of sensors to control the auto variable transformers.


AVE optimizes your electrical network efficiency to save energy, protect assets and save costs.


1) Prevent phase voltage imbalance

2) Prevent phase angle differential

3) Eliminate transients and voltage spikes (lightning strikes)

4) Prevent Arc flash

5) Prevent phase voltage instability

6) Reduce voltage harmonics (Phase – Ground)

7) Reduce waveform distortion

8) Eliminate noisy ground reference and frequency instability

9) Prevent arcing ground faults

10) Provide a good and stable ground reference for power system stability to ensure optimal operation of control systems without interruption.

AVE Benefits:

1) Increased operational efficiency

2) Reduced energy consumpion

3) Extended lifespan of electrical componets and machines

4) Reduced  dangers of arc flash and ground faults.

5) Reduced CO2 emissions

6) Reduced maintenance and downtime

7) Saved cost 

8) Increased safety for personnel

9) Advanced Power Quality Analyzer, including webserver, HMI-panel and energy management software.

10) Alarms are given for various events like ground faults, transients, voltage imbalance, high harmonic distortions etc

Documented and proven technology 

The Automatic Voltage Equalizer have been through an extensive testing program including laboratory testing at PNDC (Power Networks Demonstration Centre). The full test report is available on our website under Downalods. 

Units have been installed with great success in several countries world wide, including Norway, UK and South Korea.

Picture above shows AVE cabinet with the  three specially designed single phased auto variable transformers.

Above you can see the result of one of the tests completed at the Power Network Demonstration Centre. As a baseload during the test we had 3 power-resistors each at 10 Ohm connect in delta, consuming around 22,2 kVA. To induce a voltage imbalance, one 30 Ohm power-resistor was connected between phase A and B, which induced close to 9% imbalance.

From the graph one can see how the voltage imbalance is instantly reduced to 1.32% and consumption is reduced with 350 VA when the unit is turned on. By adjusting the ratio on the variable transformers, both the imbalance and energy consumption is further reduced. The energy reduction was close to 500VA.

If we calculate this into kW hours over a year, it would add up close to 4400 kWh. Depending on local electricity costs, one could just imagine the savings possible on larger scale. system!!

The Waveform log above is captured by EMES PQA during welding machine operation at Samsung Heavy Industries and shows the exact moment when AVE is activated. The Waveform before the AVE activation is distorted with a high voltage unbalance (8-9%). After AVE activation, we see a short transitional period of 30-40ms where the unit stabilizes the system, removes harmonic distortion, eliminates transients, and reduces voltage unbalance (0.5%).  After the AVE is activated, we can see a perfect sinus waveform and a 100% balanced system.

Picture shows how fast the AVE reacts to a voltage imbalance and stabilizes the system. The system is brought back in balanced and fully stabilized in less than 0.9 mS

AVE test results and detailed test report can be obtained on our website. https://emenergysolutions.com/downloads/

Pictures shows AVE installed at Samsung Heavy Industries optimizing power quality at one of their robotic welding factories inside the shipyard.

The poor power quality had a direct impact on the welding quality, which resulted in increased arc-flare, blow holes and other welding related issues.

The instant that the AVE was activated major improvement to welding quality could be noticed. The arc-flare was noticeably shorter and the operators reported that even the sound of the machine was different. In addition to greatly improved welding quality, Samsung Heavy Industries will from now on also benefit from reduced energy consumption, extended life time of machines and components such as welding inverters, and a more reliable, cost efficent and safe electrical system. 

Welding inverters operate at switching frequencies typically 10 kHz or higher and AVE is the only system that is capable of suppressing and stabilizing the voltage system at these frequencies due to its unique technology!



The AVE is designed for use in a wide range of industries With AVE installed all types of three-phase power systems be optimized and protected, one AVE is required for each power transformer. The AVE provide transient voltage spike protection, arcing ground fault protection, phase voltage balancing, and arc flash mitigation. Cost and energy saving by installing AVE will typical cause a payback in one year or less.

Types and models