otis elevator company is getting new products to market faster with a design methodology that integrates thermal and electromagnetic compatibility (emc) analysis to meet increasingly tough requirements for elevator controls. integrated thermal/emc simulation with the flomerics integrated analysis environment helps ensure that the first prototype works as predicted from a thermal and emc standpoint, which reduces prototyping expenses and helps to get the product to market earlier.

"the integrated approach to thermal and emc design is ideally suited to meeting increasing electronics packaging design challenges that are caused by higher power density and more stringent emc regulations," said randy dube, principle mechanical engineer, otis elevator company, farmington, connecticut. "performing thermal and emc design in parallel helps us achieve greater collaboration between what are traditionally discrete engineering specialties to reduce risk and avoid substantial delays from iterative design changes."

the electronics packaging challenges facing the designers of elevator control equipment have significantly increased over the past decade. market demands for reduced space utilization within the building by the elevator system has driven the design of smaller sized controls, which makes thermal management more difficult than in the past. at the same time, (emc) design for elevator control equipment has become more challenging than in the past, largely due to stricter requirements that have been issued by the european community. just as important, both of these factors interact with each other to further increase the difficulty of simultaneously meeting all the requirements.

these issues played a major role in the design of a new regenerative variable frequency drive for ac motors used to drive otis elevators. a major concern was that thermal design often conflicts with emc design so fixes that are implemented to address thermal concerns often exacerbate or create emc problems. otis addressed this concern by working on thermal and emc design in parallel using flomerics’ integrated analysis environment which makes it practical to address thermal and emc design in a collaborative manner from the earliest design stages.

the effectiveness of otis’ improved engineering methodology is illustrated by the fact that when components finally became available to build the first prototype, temperatures and emc performance were as predicted within the expectations requested of the simulation tools. all thermal and nearly all emc requirements were met from the very first iteration. minimal modifications were required to the enclosure and the cooling system from the first prototype through to the final release.

"thermal and emc design challenges are increasing with each new generation of control equipment," dube said. "the ability to evaluate design alternatives from both a thermal and emc standpoint prior to the prototyping stage helps us address these challenges by optimizing the design in software long before we reach the prototype phase."