EM Energy Solution’s technology is based on the fundamentals of electromagnetism, so that the unit will react on electrical noise and imbalance with the speed of the electromagnetic field.
The AVE’s main purpose is to stabilize the voltage in reference to ground, and by doing so it will prove highly beneficial against well known power quality related problems.
The unit’s main components are 3 single-phase variable isolation transformers that have a wye connected primary with neutral connected to ground, giving it a fixed reference to control the voltage. Secondary side is connected in delta in series with a pure resistive load.
With this setup, any voltage imbalance will induce a current in the secondary side circuit, which in turn will feed energy back to the low voltage phase from the high voltage phases together with dissipating excess energy in the resistor. The variable isolation transformers will also make it possible to optimize the flow of energy in such a way that voltage imbalances can be kept within 3 percent.
In an ideal world where you have a pure 3-phase supply consisting of only the fundamental frequency without any harmonic components and where each phase has the same amplitude and 120-degree phase shift, the system will be fully balanced in respect to primary side ground reference. This means there will be no induced current in the transformers secondary side and the AVE will not consume or transfer energy between the phases.
As we all know, there is no such thing as an ideal world, and in that respect, there will always be some amount of noise and voltage imbalance in a 3-phase supply.
When the unit is connected and transformers energized, it is ready to counteract any kind of power quality issue that distorts the 3-phase voltage supply. Any kind of unsynchronized imbalance on the voltages will be detected on the transformer`s primary side and the unit will start to counteract it.
The amount of current induced in the secondary side is based on the amount of voltage imbalance on the primary side. If one applies the well known rule of Kirchhoff’s fundamental voltage law, which states that the algebraic sum of all the voltages around any closed loop in a circuit is equal to zero. The voltage drop across the impedance in the circuit can be determined by the vectoral sum of the voltages in the transformer`s secondary side, which again can be used to calculate the current in the circuit.
Knowing both the secondary side current and the voltage drop, energy transfer can easily be calculated.
One would believe that balancing voltages between phases will require large amounts of energy, but this is not the reality. As an example, we can take a look at one of the tests we did at the Power Network Demonstration Centre in Scotland. We saw that our unit only consumed 18.6mA in the secondary side circuit to correct a voltage imbalance of 12%. The test was done by adding a single-phase load on to a transformer operating with a base load of 63% of transformer capacity. Detailed information about this test is available under Downloads on our website.
In any 3-phase distribution system there will always be stray capacitance causing leak current to ground. In situations where AVE is not installed this energy will normally go to waste and cause additional costs in terms of higher electricity bills.
The AVE will prove highly beneficial against capacitance leak current to ground, in the way that it uses this energy to balance and optimize the power quality instead of wasting it. This will give large savings in terms of reduced electricity bills.
When it comes to voltage harmonics this is high frequency voltage imbalances, and due to the fact that the AVE reacts with the speed of the electromagnetic field, it is able to suppress zero sequence voltage harmonics up to very high frequency ranges.
For transient surges such as voltage spikes caused by lightning strikes this will be detected as a very large voltage imbalance which again will cause the unit to react more. The higher the voltage imbalance the more the AVE will counteract it. The problem with surge protection devices is that they are to slow to prevent damaging voltage levels entering into the system. Because of the speed of the AVE it can suppress the transients before they reach damaging levels, thus protecting all downstream equipment.
AVE is designed to be connected in parallel on the transformer`s secondary side and as close to the transformer as possible. This will ensure optimal protection of all downstream equipment connected to the same distribution line.