Passive Power Quality Solutions

Constant Voltage Transformers (CVT)

CVTs provide stable, isolated voltage for sensitive equipment, reducing sags, noise, and disturbances across your loads.

Passive Filters

Passive filters target specific harmonic frequencies, reducing distortion and improving power factor.

Product Agnostic - Engineer Designed

Our engineers design and specify the right solution for your site. Our first‑principles approach ensures you’re never sold equipment you don’t need.

Reactors (Line/Load)

Line/load reactors add series impedance to smooth current waveforms, reduce voltage spikes, and protect drives from network-induced stress.

• The CVT operates in the magnetic saturation region. When the iron core of a transformer is in saturation, relatively large changes in winding current results in very small changes in magnetic flux.

• Winding current and magnetic flux are proportional to the input and output voltage, respectively.

• This means that relatively large changes in input voltage result in small changes in output voltage, thereby acting as a voltage regulator.

Constant Voltage Transformers (CVT)

How does a CVT work?

• A Constant Voltage Transformer (CVT), or ferro-resonant transformer, is a specialised transformer that provides a stable, regulated output voltage despite significant input voltage fluctuations.

• Using a magnetic shunt and a resonant capacitor, it utilises ferro-resonance to provide surge protection, noise filtering, and galvanic isolation.

• Ideal for sensitive electronic equipment that has a narrow voltage supply range.

What is a CVT?

Comparison to Transformers (Linear)

• Operation in the saturation region has the disadvantage of poor electrical efficiency and yields higher levels of harmonic distortion than operating in the linear region.

• Standard power transformers are designed to operate in the normal range (blue) where electrical efficiency is higher.

• While standard power transformers have some minimal capacity for voltage regulation, their primary purpose is to transform voltage from one level to another with higher electrical efficiency.

• Reactors can protect motors, VSDs and other sensitive electrical equipment and increase their reliability and life span by absorbing disturbances in the line current, preventing overvoltage trips, improving total power factor, and reducing nuisance tripping.

• Reactors can also help reduce harmonic currents by adding impedance on the line, hence reducing voltage harmonics and ensuring compliance.

• Line and load side reactors reduce available voltage to the input of the motor drive and to the motor respectively, and therefore important not to oversize the reactor.

• It is known that placement of the reactor is a critical consideration as it may resonate with capacitors however, our engineers have the experience and knowledge to guide you on its placement.

Reactors

Line Side Reactors

• The line current into a six-pulse rectifier is shown. The twin peaks in every half cycle are due to dominating capacitive current.

• The incorporation of a line reactor will tend to smooth the current and hence lower the peaks.

Load Side Reactors

• Long motor cable runs and fast switching speeds can create reflected wave voltages and high-frequency noise that place excessive stress on motor insulation.

• Load reactors are especially effective in these applications, as they slow the rate of voltage rise and dampen waveform transitions.

• This protection helps extend motor life, reduce nuisance faults, and prevent premature equipment failure.

What can reactors do?