Up to 64 ELP-GXS modules can be arranged in multi-load, series and parallel configurations with active load sharing in to the low MW range. Each module is able to operate independently, so that systems can be reconfigured, expanded or broken up as needs dictate. Inbuilt system comms allow users to switch between various set-ups.

The modular approach is useful for test houses and research labs who regularly test different sized power devices. Individual modules can be used for the day to day testing of multiple small devices, then grouped together for larger projects.

Internal Resistance Range

Each module is built with a user programmable internal resistance range as standard. This makes the power systems ideal for simulating energy storage devices such as battery packs, fuel cell stacks and super capacitors. The exact range varies by module and can be viewed in the datasheet selection table. An extended programming range is available (option /IRXTS).

Sense Compensation

Sense plus terminals are built into the ELP-GXS for the connection of sense wire which compensates for voltage drops in the load lines. This has a number of advantages over traditional sense. It is permitted to interrupt the load line during operation (voltage on). The maximum voltage drop compensation is adjustable. 

The voltage difference between ELP-GXS and the sensing point is monitored. If a set limit is exceeded, the ELP-GXS unit shuts off. This is particularly useful for applications with long cables often prone to unwanted voltage drops.

Every module features constant current, constant voltage, constant power as standard. Adjustable internal resistance is also provided.

For systems with bidirectional source and sink capabilities please see our LAB-GSS models.

A variety of control methods are available. As standard each module is built with isolated analogue and RS-232 interfaces. Front panel control and display along with IEEE 488.2 (GPIB), USB, RS-422 and Ethernet interfaces are optionally available.

An optional CANmp high speed digital interface operating at 1kHz is particularly popular with automotive users. The interface gives users the capability to customise the CAN protocol. Up to 50 messages are user configurable. Messages can be sent cyclically or upon receipt of a sync or syncID signal. 

RS-232 Interface

The RS-232 interface is configured as a Sub-D 9 pin connector (female) and is located on the front panel. This interface can be optionally moved to the rear panel. The graphical user interface, TopControl is operated via RS-232. The software runs on Windows and allows the user to control, measure and configure the power system.

Analogue Interface

The control port is configured as a Sub-D 25 female connector and is located on the rear panel. It allows output values to be set and read proportionally using a 0-10VDC analogue signal. Digital inputs and outputs enable various functions such as the interlock and output ON/OFF. A 10VDC reference is provided for analogue control. Digital functions are switched via a high/low signal. A 24VDC supply voltage is provided for these functions.

Standard TopControl GUI

All ELP-GXS units come with a simple and intuitive TopControl operating GUI as standard. Live values of the power system are displayed graphically along with any warning and error messages. The software provides a variety of second level parameters, ideal for users who like to optimise their test processes. In standard user mode the operator can remotely program set values, enable voltage output as well as the ability to anlyse different variables including set and actual values via the integrated scope.

The scope function can simultaneously record up to 8 system variables. Recording can be started manually or by a defined trigger event from any variable of the system. All actual and set values (currents/voltages/power/internal resistance) can be recorded. Other recordable items include system temperatures, intermediate DC circuit, low voltage auxiliary power supplies, error related values and variables from the controller section.

A password protected section is available to the advanced user and service technician. In addition to the standard functions the authorised user is able to:

• Program linear ramp functions at start up and set value steps during operation
• Configure multi-unit operation
• Program the PID controller parameters
• Program the unit's limit values
• Calibrate and adjust values as necessary
• Update the firmware

Function Generator (Option /TFE)

Complex DC sink waveforms can be created through an optional embedded function generator. The highly programmable nature of the function generator allows users to plot out exact waveforms. This is often advantageous when emulating a power device with a very specific behaviour profile. For example, when quality testing fuel cells, a specific discharge profile can be programmed and replicated.

As well as custom shapes, standard square, sawtooth and sine waveforms can be plotted against time. Voltage/current and voltage/power relationships can also be programmed where necessary. Parametric programming is possible, where instead of the time axis, an input variable V_IN, I_IN or P_IN can be selected.

Soft Tools

An API for dotNET/C# programming is provided to simplify the integration into 3rd party control and measurements software platforms such as LabVIEW and Matlab. The API can be used to integrate into Python or remote systems based on the REST architecture.

Battery Emulation (Option /BATSIM)

BatSim provides a convenient method for the ELP-GXS to emulate different sized battery stacks. Nearly all relevant electrical characteristics are programmable, including the number of cells, energy capacity, cut off limits, chemistry type and nominal voltage.

Battery/Capacitor Discharging (Option /BATCONTROL)

Battery and capacitor discharge profiles can be implemented through the GUI. Previous data obtained can be imported and recreated, allowing the ELP-GXS to simulate a real world usage profile inside a lab environment.

Capacitor Simulation (Option /CAPSIM)

The electrical characteristics of a real capacitor stack can be emulated when CapSim is installed with ELP-GXS modules. Number of cells in series/parallel, state of charge, cell cut off limits, dynamic capacitance and resistance are programmable.

Integrated Safety Relay (Option /ISR)

For additional safety, a mechanical interlock is available for the mains connection of the ELP-GXS. The integrated safety relay provides shutdown safety according to EN 13849-1 category 2/3. The ISR is connected to the external safety switch loop. If the external loop is opened, the DC-loadside of the power system is powered down immediately.

Protection Against Output Bars (Option /PACOB)

A specially produced cover is available which provides protection against accidental contact of AC and DC current bars.

Automatic Voltage Matching with RPP (Option /RPP)

When researching energy storage devices, Reverse Polarity Protection (RPP) is recommended for devices without an automatic voltage matching circuit. With the ELP-GXS energised but loadside off, the RPP senses the voltage of the connected energy storage device. A contactor is closed after matching the voltage, to prevent large inrush currents and arcing on start up. 

Remote Control Unit (Option /RCU)

The RCU is an external control unit for controlling multi-module systems, which reduces response times when implementing complex changes. The RCU is available as either a desktop unit or a 19" rackmounting module, with or without an emergency stop.

Liquid Cooling (Option /LCAL)

Liquid cooling of the ELP-GXS is available for units which may be subject to naturally hot or uncontrolled environments. This enables operation up to 45°C with no performance derating.

The standard 19" ELP-GXS rackmounting modules can be treated to a laboratory rack or flight case integration. Common options include mains cables, passive indication of any residual DC voltage, isolation monitoring of DC cables and a panel mounted emergency stop. Switch panels with removable DC links can be fitted for modular systems. This simplifies the reconfiguration between series, parallel or independent use. Simple wheeled cabinets are also available. 

Having a programmable power system mounted into a flight case on castors is often advantageous, especially when several departments or test cells share the same equipment. Multiple power systems can be fitted into the same flight case. Door hangers are fitted for convenience. Existing ETPS systems can also be retrospectively integrated into new flight cases where requested.

If your test requirement is short term, we have DC electronic loads in our rental range up to 216kW/2000V/3000A.

The versatile programming capability of the ELP-GXS ensures that it is popular across many research and development sectors. Common applications include battery/capacitor emulation, fuel cell loading, component lifetime testing, as well as the testing of rectifiers and DC-DC converters.