Voltage sags in the automotive industry: Analysis and solutions

• We analyze voltage sags and their effects in an actual automotive industry.
• We propose a procedure to decide where to apply the compensating solutions.
• The procedure is a general method to face power quality issues in large industries.
• The procedure includes the definition of a new index.
• The implemented solutions and their benefits are illustrated by an ex-post analysis.

The objective of this paper is to present the actual solutions used to solve process-interruption problems caused by voltage sags in a large automotive industry. A brief description of the industrial process is presented to focus attention on only the production units that are most vulnerable to voltage sags. Then, the industry's experience with interrupted production is reported and analyzed. A two-step procedure is proposed to evaluate the equipment that should be targeted for the application of compensating solutions. In applying this procedure, a criteria based on the Kaizen approach is used to select both the areas for intervention and the types of compensating solutions. The results consist of adequate compensating devices, characterized by very low costs in comparison to the costs associated with lost production, due to the negative effects of voltage sags. The effectiveness of the proposed solutions was proven by an ex-post analysis that lasted for one year after the intervention. The main conclusion of the study provides evidence that supports the real possibility of solving extensive voltage sag problems in large industries using economical devices. The practical implications of the method were demonstrated by extending it successfully to additional production units in the same factory.