NELCO LIMITED

MEDIUM VOLTAGE AC DRIVES

A traditional VFD features up to five separate components, such as harmonic filter, power factor correction, transformer, power converter and motor filter. However the perfect harmony's topology integrates these elements so an isolation transformer and power converter are the only major components required.

Versatility
The proven technology of the Perfect Harmony drive meets the needs of customers in many industries, from water treatment to energy production to chemical processing. To accommodate the specifications of each customer and each environment, the Perfect Harmony's configuration can be modified for a custom-engineered solution, all developed from proven SOP (standard operating program) function blocks. NELCO is the only industrial power controls manufacturer to offer this level of system versatility to its customers. And when it comes to retrofits, the Perfect Harmony upholds its reputation as the world's most versatile medium voltage drive. The Perfect Harmony is compatible with existing motor systems, regardless of age, brand or voltage/frequency - even synchronous motors. The Perfect Harmony's synchronous transfer capability also puts it in a class by itself. The drive has the ability to accommodate a bump-less transfer of one drive to run multiple motors in a defined process sequence.

Efficiency
The integration of the Perfect Harmony's drive and transformer as one unit greatly simplifies installation and reduces start-up costs. This integrated drive system also maximizes the Perfect Harmony's efficiency in a number of critical areas. Integration helps provide quick and reliable start-ups, a smaller footprint and allows for the addition of power conversion redundancy. It all adds up to a smaller, more efficient and reliable system.

Reliability
The reliability of the Perfect Harmony drive is second to none due to NELCO's common-sense approach to component selection and design. Insulated Gate Bipolar Transistors (IGBTs) form the backbone of the Perfect Harmony drive. Built in high volumes and serving as a proven power device across the industrial power control industry, IGBT technology has been in existence for more than a decade. The stability and availability of IGBTs give you reliable, long-term, life-cycle confidence. But that's just the start of our forward-thinking design. The Perfect Harmony is engineered to withstand failures that would overwhelm conventional drives because we've added redundancy options into the system. Our patented, cell-based configuration maximizes uptime and simplifies modifications. Through a redundant bypass control that is completely separated from each power cell, the Perfect Harmony ensures automatic bypass of a failed power cell in 250 milliseconds (less than 1/4 of a second).