Converters for the self-sufficiency of EV charging stations

In a world that must reduce its carbon footprint, electric vehicles are the future of traffic. They need charging stations whose power levels are in the region of several kW. These stations are equipped with the latest semiconductor technologies and are being continuously improved. At the same time, the AC/DC accessories must be adapted and developed further to match the same requirements for quality and deliver reliable performance. In addition to that, there are high expectations for insulation strength against overvoltage and durability during voltage dips on the network. Charging poles are often freestanding, and when lightning strikes nearby, it can cause transients. These supporting power-supply units must withstand them.

The RECOM delivery program includes AC/DC power supply solutions and DC/DC converters with galvanic or increased potential isolation, featuring very high insulation strength.

The 5W RAC05-K/480 is an OVC III classified AC/DC converter with a broad 85VAC to 528VAC input voltage value, allowing 100VAC to 277VAC for phase-to-neutral connections in single-phase systems or 208/480VAC phase-to-phase connections in three-phase systems without a neutral conductor. The 5V, 12V, and 15V outputs feature an insulation strength of 4kVAC for one minute. The RAC05-SK/480 operates at temperatures from -40°C to +80°C, making it suitable for exposed environments such as charging stations.

For higher performance, the RAC10-SK/277 series serves as an auxiliary power supply. The input voltage value spans from 85VAC to 305VAC, supporting single-phase connections from 100VAC to 277VAC. Like the RAC05-05SK/480, the RAC10-05SK/277 is OVC III compliant. These cost-effective components, certified for industrial and household use (IEC 60335), offer output voltages from 3.3VDC to 24VDC and ±12VDC or ±15VDC, covering most applications. A key feature is the momentary overload capacity of 140%, making them ideal for accessory supplies in battery-charging and monitoring systems with higher inrush currents. Both series comply with EMC standards (Class B) without external filters, have low idle-running and standby consumption, and feature a space-saving 2" x 1" footprint for board mounting.

The RxxCTxxS is a 5kVAC isolated DC/DC converter (1kVAC,rms working voltage) with reinforced insulation in a low-profile SOIC package. This allows it to be treated like any other IC and directly soldered. The regulated output voltage is short-circuit-proof and available in 3.3VDC or 5VDC options. The 500mW power output is sufficient for sensor or communication interfaces. The operating temperature value ranges from -40°C to +110°C with a 400mW load and a 5VDC input voltage.

The RKE series features a conventional SIP7 (THT) design with a 1W output power, making it a cost-effective solution for price-sensitive applications. It supports 5V, 12V, or 24VDC input voltages. The 5VDC output voltage has a high insulation strength of 4kVDC, suitable for electrically isolated interfaces, controller, or sensor electronics, such as charging current monitoring or battery voltage measurement. The RHE converter offers up to 81% efficiency. If the circuit board is not interference-suppressed, an additional LC EMC filter is required. Both DC/DC converter types are advantageous for battery chargers and vehicle chargers, including wallbox applications. They are also widely used in industrial applications requiring strong electrical isolation.

EV charging stations for 48V batteries are designed for smaller electric vehicles such as Automated Guided Vehicles (AGVs), material handling systems, compact vehicles like golf carts, and plug-in mild-hybrid (PHEV) cars. Since DC voltage remains below 60VDC, electrical isolation is not required, allowing the use of non-isolated converters These converters are more compact, efficient, and cost-effective than insulated alternatives.

The RBBA3000 is a high-performance converter with an input voltage range of 9V to 60VDC and a stable output voltage of 0-60VDC at 0-50A load. This enables up to 3kW of power in a compact half-brick format (63.2 x 60.6 x 13mm). A key feature is the Imon pin, which allows load current monitoring without a shunt resistor. Other applications include 48V to 24V or 12V to 24V battery power conversion, battery voltage stabilizers, and high-capacity power lab DC power supplies. With appropriate cooling, it operates at full power from -40°C to +85°C. Like all RECOM products, the RBBA3000 comes with a two-year warranty.