With this unrivaled expertise in electronics design, control, and manufacture Mitsubishi Electric delivers the highest reliability and highest efficiency in uninterruptible power supplies
Three level topology provides the base building blocks to create UPS products that are capable of >97% true online double conversion efficiency. First introduced to the North American UPS Market in 2008 in the 9900A series 3 phase UPS modules, Mitsubishi Electric now includes 3 level topology in all of its 480V UPS products. Mitsubishi has led the way in this technology and now has over ten years of experience in its design, construction, and operation. For more information on three level topology, see the Three Level Topology White Paper.
After the release of three level topology, Mitsubishi Electric pursued the next major advancement in UPS technology, Silicon Carbide (SiC). As the latest in high power semiconductor devices, SiC is the most disruptive technology in the power electronics industry since the invention of the Insulated Gate Bipolar Transistor (IGBT). UPS module construction utilizing SiC technology coupled with three level topology has led to the creation of the smallest, lightest, and most efficient UPS modules in the world. The SUMMIT Series® UPS features SiC technology. Module efficiencies of up to 99% in true online double conversion are achievable without the use of line interactive technology. For more information on Silicon Carbide Power Electronics, see the SiC White Paper.
The removal of the transformer from UPS modules is the key to achieving superior efficiencies. In order to do this, key elements of UPS design must be reviewed. These include harmonic content, system fault tolerance, negative and zero sequence currents and system grounding stability. Mitsubishi Electric’s Virtual Neutral provides the means to remedy all the adverse conditions that can be caused in a transformerless UPS. It also provides harmonic mitigation that is unparalleled in the UPS industry. This creates the perfect environment for the removal of excess transformers from the critical power path, greatly increasing overall UPS efficiency and reducing UPS footprints. Transformerless White Paper
Double conversion UPS modules provide uninterrupted power to critical loads. They take incoming utility power, filter it, convert it to DC and then use the DC power to recreate a perfect AC output from the inverter. The inverter is also supported by a DC source that may include batteries or flywheels. The critical load is then protected from any transient or voltage anomaly including surges, sags, swells and line drops. Line interactive UPS modules have the capability of running in double conversion but are normally operated via a secondary power path. This power path provides unregulated power to the critical load and only interacts with the utility in the event it exceeds specified values. This leaves your site vulnerable to voltage transients and harmonic issues, all for a <0.3% efficiency gain over a double conversion Silicon Carbide based UPS module. The line interactive UPS also has a tendency to call upon the batteries more frequently than double conversion UPS modules, shortening the battery life and leading to costly battery change outs. If reliability is key, then double conversion is the best choice for critical loads.
There are many UPS configurations available when designing a critical load application. The complexity of each design varies based upon budgets, uptime requirements, risk aversion, maintenance plans, and existing infrastructure. These designs are typically broken down into four tiers. Each tier expands on the reliability and maintainability of the previous tier.
Each Tier has different advantages and disadvantages and choosing the right one for you can be difficult.