Installation of Variable frequency drives (VFD’s) with Industrial, Commercial and Domestic application motors leads to many benefits and hence we can have an improved total cost ownership.

Most of the Pumps and fans in Industrial, Commercial and Domestic applications runs with constant speedwith either manualcontrol or semiautomatic for controlling the flow rates or speed in pipelines or speed of fans which leads to a condition that motor is not operated at max efficiency points. Also, it requires involvement labor personal during on/off times that leads to operational cost.

There are many alternatives are possible in terms of energy efficiency and operational control effectiveness. By deploying VFD’s in such applications leads to variable speeds and energy efficiency. VFD’sdelivers immediate energy savings in energy consumption and brings long-term benefits such as enhanced life and reliability.Also, by deploying simple logics, on/off can be managed through Auto on facility of the VFD’s. Having said, VFD’s offers numerous benefits and helps in achieving overall cost of ownership

The above stated reasons undoubtedly revealthat VFD’s are the need of the hour and we should deploy as much as possible to gain long term benefits on Industrial, Commercial and Domestic applications.

• Energy savings: Energy savings can be achieved by deploying VFD’s based on the application requirements and running motors appropriately at partial loads and hence immediate realizable energy savings in every minute and hour.
• Starting current: VFD shapes the voltage and frequency over a period during start/stop. Depending on the needed acceleration and motor load, the motor is fed via VFD’s and maintains lesser currentfor AC motors during starting. This helps to achieve peak demand reduction at PCC or metering point during stating of the motor by the industrial, commercial and domestic customers.
• Motor independence: With increasingly stringent demands on motor efficiency, new motor technologies such as permanent magnet (PM)motors and synchronous reluctance (SynRM) motors are introduced along with traditional Induction motors. This means that VFD’s should meet such challenging control requirements. Danfoss VFD’s built with technologies such that it can cater all such motor requirements to operate at optimum efficiency and VFD’s becoming a motorindependencecomponent/device at system level
• Controlled acceleration/deceleration VFD allows acceleration/ deceleration control to the user such that this can be controlled based on motor and application requirements. Acceleration ramps up smoothly from zero speed to required reference level and deceleration ramps down smoothly from max or running speed to zero speed.
• Improved Operational efficiency: VFD’s helps us to do things automatically based on reference settings i.e. Product/ System with various inbuilt functions of VFD’s reduces involvement of labor, parts replacements, frequent maintenance, production loss and improved customer end products Operational efficiencyin industries, commercial and domestic environments.
• Reduction on electricity bill: VFD’s takes required energy from the source to load and operates the motor at optimum/partial speed that usually resulting in 10-60% in real application environments. This gives immediate electricity bill savings on month on month to customers.
• Capital expenditure savings: System with VFD helps us to avoid inrush currents during starting which helps indirectly to avoid overdesign on electrical system components in the upstream of electrical installationsstarting from PCC’s onwards up to VFD and hence cost savings on capital expenditure.
• Maintenance expenditure savings: By deploying VFD’s in products/systems, the electrical, thermal and vibrational stresses can be reduced which helps to achieve lesser maintenance expenditure in terms costs for parts to be purchased and labor to be involved for such maintenance activities.
• Long life – The reduced starting current demand results in lower heat generation and less stress on the motor’s components, cables, switch gears and hence enhanced system components life.
• Reliability:Built to last, this robust drive operates effectively and reliably even with the most demanding applications and in the most challenging environments. Its cutting-edge Digital processors, IGBT, EMI/EMC, thermal designs and unique back-channel cooling make VFD’s one of the most compact and mostefficient drives in the market. Its not only at the product level and it ensures reliability at system level in real time applications.

Authored by:

Dr S Paramasivam
Sr Manager, PE R&D Danfoss India