Skip Navigation LinksHome | Specialist | Bidirectional Power Supplies | High Power Bidirectional

High Power Bidirectional

High power bidirectional DC power systems are ideal for industrial operations. Battery emulation, motor testing and battery cycling are common applications.

The robust design of our bidirectional cabinets makes them extremely suitable for the rigours of industrial and production environments. A common application is the production testing of electric drives. The bidirectional nature of each system allows it actively decelerate the drive at the end of testing. This increases efficiency as you don't have to wait for a motor to freely spin and stop before you can test the next one.

Another popular application of the cabinets is powering two dynamometers operating back to back, as they can feed DC energy into the circuit to compensate for any losses. The system's fast response time allows it to react to any sudden motor step changes during testing.

LAB-SCUBI

Single Channel Bidirectional Systems

LAB-SCUBI systems are available in blocks up to 2MW, ideal for high power applications where modularity is not required. Each unit has an extremely wide operating range. When functioning as a load, selected models will operate from 1000V all the way down to 5V without current derating. This allows the same system to test 48V mild hybrids and 800V pure electric vehicles.

An extended feature set includes voltage and current ripple below 0.1%, sense terminals for voltage drop compensation as well as a range of protection features. For remote control a CANbus interface is provided as standard along with soft tools for LabVIEW integration.

The robust design makes it extremely suitable for the rigours of industrial and production environments. A common application of the LAB‑SCUBI is production testing of electric drives. The bidirectional nature of the system allows it actively decelerate the drive at the end of testing. This increases efficiency as you don't have to wait for a motor to freely spin and stop before you can test the next one.

LAB-MOBI

Multiple Output Bidirectional PSU

Every LAB-MOBI is built with 2 or 4 output channels which provide both DC source and sink functions. While each channel is independently controllable they share a common rectifier section. This saves cost when compared to separate bidirectional systems.

Energy can be recycled between channels above the unit's nominal power. For example a 4 channel 100kW system can sink up to 600kW from a source, such as a battery pack, in the first channel and use the energy directly in the second. The unit's remaining 100kW capability can still be used across the other 2 channels to and from the grid.

A popular application of the LAB‑MOBI is powering two dynamometers operating back to back, as it can feed DC energy into the circuit to compensate for any losses. The system's fast response time allows it to react to any sudden motor step changes during testing.

Standard Features

  • TFT Touchscreen Display
    A large TFT front panel screen displays programming functions and live values from the power supply. Current and voltage settings are adjustable via the panel as well as a host of other features. The screen provides users ease of access and speed when implementing their test programs.
  • Fast Dynamics
    The high dynamics of the system allows users to switch quickly between quadrants. This is particularly useful when performing tests on bidirectional devices with fast current step changes such as super capacitors and electric motors.
  • Sense Compensation
    Terminals are built into the LAB‑SCUBI for the connection of sense wire which compensates for voltage drops in the load lines. This is particularly useful for applications with long cables often prone to unwanted voltage drops. A common example is when powering motor equipment in test cells, as the power supply is often in a separate room requiring extended connection cables.
  • CANbus
    Each system is built with a CANbus interface which operates at 100Hz. The fast sampling frequency allows users to record quickly changing data, so that they can identify what's happening at a particular point in time. An optional Modbus interface is also possible.

Options & Interfaces

Highlighted Options

  • Switchable Output Capacitors
    Switchable output capacitance is available to improve stability when operating in constant voltage mode. This is particularly useful to assist the very fast peak demand of current when testing drives. Some electric drives are susceptible to damage if the voltage drop is too low, so a stable voltage is often vital to prevent damage to the drive. If a test routine requires fast dynamics in constant current mode, then the additional capacitance can simply be switched to a lower setting.
  • Discharge Unit
    Discharge units are available as an additional safety feature. When the DC output is turned off, energy from the device under test will be discharged into a resistor at up to 500kW per second. This ensures that there is no residual energy on the DC link when disconnecting a device under test. This feature also works when the emergency stop button is pressed.
  • Additional Current Ranges
    A second or third current range can be built into LAB‑SCUBI systems to give better accuracy and resolution for low current applications. This is particularly useful when testing high voltage equipment, such as electric vehicle battery packs, which typically produce low currents.
  • Blocking Diode
    A blocking diode is available to provide protection for the device under test against any back EMF. This is particularly useful to prevent damage to unidirectional power sources such as fuel cells. The device provides protection up to 1200A and comes in its own wheeled cabinet with 2 voltmeters.

Application Software

Testing of Cells and Battery Packs

Battery Pack Testing

Optional software implements charge/discharge cycles to a battery pack. Using the software allows users to perform research and quality testing on batteries. This includes analysing discharge performance of the VI curve under different discharge rates and assessing the endurance of the battery after many cycles.

The user interface allows you to set voltage, current and power limits. On request a CMU data logger with up to 4800 temperature and voltage inputs is available. A burst generator to stress the battery monitoring system is also possible for more in-depth tests.

Another optional extra is the enhanced impedance spectroscopy capability. This technique measures the impedance of a battery over a range of frequencies, as well as the frequency response of the system. Using this method allows you to characterise battery packs including the energy storage capacity and dissipation properties.

Battery Simulation

Battery simulation software is also available for the LAB‑SCUBI which allows the system to emulate the electrical characteristics of a battery pack. Using the software increases reproducibility of experiments and reduces preparation time. Voltage and internal resistance levels can be set via the front panel screen.

ETPS Ltd
Unit 14, The Bridge
Beresford Way
Chesterfield, S41 9FG
sales@etps.co.uk
Problem Solving Copyright © 1999 - 2017