Modules for battery charging applications

Electric vehicles and e-mobility, in general, are the future of transportation in a world that needs to reduce its carbon footprint. To make battery-powered vehicles cost-effective, electric vehicle chargers must be as efficient and economical as possible. While power conversion stages at the multi kW level are improving with the latest topologies and semiconductor technologies, AC/DC auxiliary supplies must also match the EV charger requirements in terms of efficiency and value. Charging wall boxes and charging stations are often installed in overvoltage category three (OVC III) environments with the potential for significant dips, surges and transients from lightning strikes, which the power supplies must also withstand. Additionally, temperature variations can be extreme, and the AC supply voltage available may be three-phase 480VAC or 277VAC. Moreover, auxiliary AC/DC modules must operate reliably in this environment along with switching regulators and DC/DC converters that provide internal voltage conversion and isolation.

These series of 3W to 60W AC/DC converter modules have 85–528VAC input for the line to neutral connections in 100/115/230/277/400/480VAC single-phase systems or a line-to-line connection in a 120VAC system. The cost-effective and fully certified parts are available with a selection of outputs; they feature a wide operating temperature range of -40 to +85°C for harsh environments and are ideal for auxiliary supplies in battery charging and monitoring systems. These series comply with EMC standards without external filters and have low, no-load and standby consumption. A selection of the RACxx products is suitable for direct connection to OVC III systems. Suitable for line-to-line connections in 220/480VAC systems, the fully-certified RECOM RAC05-K/480 series AC/DC converter module provides an isolated 5W output at 5, 12 or 15VDC from a supply voltage ranging from 85 to 528VAC. The parts are EMC compliant (Class B) without external components, and the operating temperature range is -40 to +80°C. The RAC05-K/480 is suitable for direct connection to OVC III systems, which makes it ideal for auxiliary converters in outdoor battery charging stations as well as general industrial use. The 60W open frame series, RACM60-K, is fully certified for industrial, household and medical applications. The module delivers 60W of output power, from -40°C to +55°C, with natural air convection, and up to +85°C with derating or forced cooling. This series offers three different mounting options—2” x 3” or 2” x 4" footprint, and optionally with PCB pins.

Circuitry in battery charging applications often requires DC-DC converters to produce auxiliary rails and isolated power for communication interfaces. High-efficiency board-mounted products such as the 4:1 input 40W RP40 series and the 20W REC20 series feature six-sided shielding in 2”x1” packages, which are ideal for providing control circuitry power in charging stations and battery management systems. For lower power battery management applications, there is the 4:1 input 8-watt RP08 series, which includes parts with an input range of 160V and is suitable for strings of batteries. When a low-power 5V isolated rail is required, perhaps to provide a -5V supply for analog circuitry or for an isolated interface in a smart EV charger, the RFMM-0505 or RKE series converters are suitable; they feature 1W output, 4kV isolation, and comprehensive safety certifications.

Non-isolated switching regulators provide high-efficiency replacements for linear regulators in battery charging systems. The R-78E-1.0 series, for instance, peaks at 97% efficiency, with 1-amp output current from 3.3V, 5V, or 12V outputs and input ranges up to 28V. For output power up to 3kW, the half-brick RBBA3000-50 product is a buck-boost converter, which has an input range of 9–60V and an output of 0–60V that can be preset; this can be above or below the input voltage. Its typical applications include 48V to 24V or 12V to 24V battery power conversion in electric vehicles and battery voltage stabilizers in charging stations for UAVs and drones.

RECOM’s sister company, PCS, specializes in high-specification, custom power supply solutions, including battery chargers, balancers and conditioners for mobile and stationary applications. PCS products are based on successful platform designs developed for demanding environments up to defense-grade conditions. The inputs can be single- or three-phase, and the outputs can be customer-specified to 20kW or more. Bidirectional designs are available for energy recovery applications. All products provide full protection, monitoring and control through intelligent interfaces.