Benefits of Two-Leg Versus Three-Leg Power Control

This white paper discusses the benefits of two-leg power control in three-phase heating applications, particularly in comparison to traditional three-leg control. It outlines how advancements in SCR (silicon controlled rectifier) power controllers have led to more efficient methods that can reduce both capital expenditure (CAPEX) and operational expenditure (OPEX). The document explains that while three-leg control is necessary for certain configurations, two-leg control can enhance energy efficiency and load management in specific applications, such as SiC element-based tin bath roof heating in the glass industry. The paper details the design of the EPower SCR controller series, which is engineered to optimize power control for high-energy industrial heating processes. Additionally, it addresses considerations for transformer design, predictive load management strategies, and the importance of minimizing inrush currents during system startup. The findings suggest that two-leg control can provide a reliable, cost-effective solution for various heating applications.