With energy demand on the rise and the ever-pressing need for industries to decrease their global carbon footprint, a variable energy management solution has become paramount. Schneider Electric, a specialist in energy management, believes that a critical approach to energy efficiency starts by better managing motors that control pump, fan and compressor. “Research shows that these motors consume 70 percent of the energy required by industries and infrastructures,” says Anton Kotze, general manager for engineered speed drive sales at Schneider Electric South Africa. “With Altivar variable frequency drives from Schneider Electric, you can however achieve energy savings of up to 40 percent, depending on the type of installation.”

The Altivar 1200 medium voltage drive system, which was introduced to the southern African market at this year’s Xperience Efficiency event held on 26 and 27 August in Johannesburg, is designed to maximise reliability, ease of use and performance, and can be applied to three-phase medium-voltage asynchronous motors (sensor/ sensorless vector control mode) as well as synchronous motors (V/f mode). “With freely available low cost low voltage IGBT (insulated gate bipolar transistor) utilised in our multilevel technology, this drive can be used in applications ranging from simple to high precision applications,” states Kotze. The core component of the Altivar 1200 is the power cell, which is a single phase, two level output switching device, supplied by one of the 18 to 54, 700V low voltage windings of the integrated multi-winding transformer. “The main advantage of this is that the switching elements are state-of-the-art low voltage components. By putting these LV power cells in series, we achieve our output voltage, ranging from 0-11000V. The number of power cells determines the output voltage. Every cell provides a small step of motor voltage, resulting in a smooth sine waveform. With this 18 to 54 pulse phase shifting technology on the secondary windings of the transformer, we can eliminate harmonics on the input of the drive.

“The power cells are located on the right section of the drive and the transformer the left section of the drive. The drive’s interface and control system is installed in front of the drive to provide an optimised footprint. The transformer and cell section can be separated for easy installation and transportation. Adequate cooling fans on top of the panel are supplied by additional secondary windings of the integrated transformer. This avoids additional auxiliary three-phase supplies for the drive,” explains Kotze. Schneider Electric offers this transformer in a standard efficiency as well as in increased high efficiency. Benefits include an easily understandable multilevel architecture that can save money when it comes to maintenance – fewer spare parts are needed because there is only one power cell design for the whole drive. This results into a smooth output voltage because each power cell provides only a small step of the voltage. The Altivar 1200 also includes an optimised combined cabinet with front access, enabling easy entry to the control and transformer cabinet. “This not only makes the installation and maintenance operations easier, but also saves about 30 percent on floor space,” comments Kotze. As a certified IP31, IP41 and IP42 cabinet – even with top cooling fans – the Altivar 1200 proposes high performance in the standard execution, offering comfort and reliability with its interlock system, large 10 inch HMI, new easy software configuration, internal lighting, uninterruptible power supply and more.

Kotze emphasises that a total harmonics distortion of current of less than two percent is obtained, thanks to the multi-level technology that draws a clean sinusoidal waveform thus fulfilling major standards. “The quality of the output voltage creates no stress on the motor bearings, windings and terminals, avoiding special and expensive dv/dt mitigation equipment for the motor. Due to this output sinewave, the Altivar 1200 can run long motor cables of two kilometres and more without additional components. These benefits make the ATV1200 the ideal retrofit drive for old motors where insulation levels are unknown. Added to this is the well arranged sharing of cooling airflow managed by only the main cooling fans, thus avoiding bottom transformer fans and cooling fans on the electronic compartments,” he says.

Also noteworthy is the product’s friendly and easy-to-use interface with LCD touch-screen and a Windows arrangement to guide the user to the required result in just a few touches. “Control features allow results to be available at the user’s fingertips. It has a dedicated multi-level menu to guide the user and comes standard with different access levels for service and commissioning engineers, such as operator, manager and administrator. The software is also available in multiple languages and consistent with all other menus within the Altivar ranges.”

The Altivar 1200 range covers kilowatt ratings up to 16,2 MVA and voltage ratings from 2.4kV to 11kV. The range is applicable in all industries from metals and mining to oil and gas to power, as well as water and wastewater. “Combine this with a complete service and support team, and you won’t have to look further than Schneider Electric for  your definitive turnkey LV and MV variable speed drive partner,” adds Kotze.