Electronic loads - Flexible power for all applications


The new EL 9000 B range is flexibly applicable. The electronic loads may, by virtue of the modular system, be combined into one device with a power of 14,400W or into a cabinet system of up to 72kW. Problems with oscillation or high frequency input voltages are overcome.

While electronic loads are used for a variety of testing of power supplies, batteries or fuel cells, they should be multi usable. EA Elektro-Automatik has recognized this need and developed a new series of electronic loads which possess multiple voltage, current and power stages for different applications: the EL 9000 B range. Power from 300W up to 72kW, voltage from 80V up to 750V and current up to 5100A are offered.

Individually customisable power
The modular system allows power parts with 600W, 1200W and 2400W to be combined at will in one unit with a power of up to 14400W. For power levels of up to 72kW a master device with slave devices are built into a single unit in a cabinet. The resulting system enjoys the same user comfort and functionality as the individual units.

Interfaces: integrated and extendable
To control and monitor the units they are fitted with a communication unit which performs as an exchange between the HMI, power unit and the outside world. As standard the units are fitted on the rear side with an analogue and USB port. All ports are galvanically isolated. A Plug & Play slot allows other interfaces for Ethernet, Modbus, TCP, Profinet, Profibus, CANopen, CAN and RS232 to be installed.

FPGA based parallel signal processing
The digital regulation and control used in the EL 9000 B series electronic loads are based on a 16 Bit AD/DA converter principle.   Because of the parallel signal processing of the FPGA the elapsed time of a signal - measurement, calculation and adjustment - is less than 1µs. Thus, a band width of 1 MHz can process current, voltage, power and resistance simultaneously. The user allotted look up tables (LUTs) also work with a band width of 1MHz. Thus complex, non-linear resistance characteristic curves, such as in LED chains or PV rectifiers, can be simulated. The table values can be generated in CSV or text format and transferred to the look-up tables via USB.

New standard: EL with extended functionality
A notable feature is the FPGA based digital function and arbitrary curve generator which enables a time based, freely programmable load profile. Hence multiple progressions such as sine, triangle or square curves can be generated. Additionally, there is a sequencing and logging function for selection and recording data and a battery management system. Other constants such as limit values for voltage, current, power and resistance, as well as time based parameters are configurable. A high definition TFT touch panel enables intuitive operation. The menu is multilingual.

Active damping, reduced capacity
EA have achieved with the new series the elimination of the deficits commonly found in electronic loads: control oscillation, voltage shift or high frequency input voltage. The EL 9000 B series secures a high current stability by using an active electronic damping of the DC input circuit. In this way, the capacity of the DC input filter is minimised and the current source protected. In addition, the loads are insulated from input circuit to chassis, operating controls and the analogue and digital interfaces. This double insulation secures a permitted floating voltage of +/- 400V. Thus, all equipment connected via the interface ports are protected against high tension.

Intelligent heat management protects against test termination
An important point is thermal protection. If components in the unit exceed a certain temperature, then commonly the input is switched off. The switching off plus the temperature delta between off and on temperature result in the load being unable to take power for a time. This results in elaborate tests being often terminated. To avoid this the new EL 9000 B loads are fitted with an intelligent heat management.