Bidirectional Devices / Bidirectional Power Supply

Bidirectional Power Supply means: power flow in both directions — to source and sink energy.

By combining a power source and an electronic load in a single unit, you get efficient, robust, and regenerative solutions for modern test tasks: from battery and energy-storage testing and DC grids to PV/inverter applications and e-mobility.

Explore the fundamentals, benefits, and use cases of bidirectional technologies below — along with our selection of bidirectional power supplies and suitable solutions from ITECH and KEWELL for laboratory use, validation, and ATE test benches.

➡️ Learn more about the technology – and discover what makes these devices special!

Power supply unit for bidirectional power supply with power sources and electronic loads

What is a Bidirectional AC and DC Power Supply (AC/DC Power Supply)?

Bidirectional AC and DC power supplies combine a power source and a regenerative electronic load in a single device. They supply the device under test and feed excess energy back into the grid in a controlled manner. This allows them to reproduce charge and discharge profiles, battery tests, BMS validation and battery simulation under realistic conditions without requiring separate source and load units.

How does the Technology Work?

Measurement circuits in bidirectional power supplies monitor the output voltage and current. The control system compares these values with the specified setpoints and adjusts the power modules accordingly.
DC devices regulate DC voltage and current both when supplying the device under test and when absorbing energy.
AC devices generate a controlled AC voltage and, depending on their design, can also specify frequency, waveform and other grid parameters. Integrated filters reduce unwanted switching components, while protection functions monitor parameters such as current, voltage and temperature.

What does 2- or 4-Quadrant Operation Mean?

Quadrant operation describes the operating ranges a device can cover and the directions in which power can flow.
Bidirectional DC power supplies typically operate in two quadrants. With one output-voltage polarity, they can both source and sink current.
A 4-quadrant DC device can generate positive and negative output voltages and can source or sink current at either polarity.
Bidirectional AC devices usually operate in four quadrants. This allows them to handle both active and reactive power components, making them suitable for testing inductive, capacitive and regenerative devices under test.

What are the Benefits of Regenerative Energy Recovery in Testing?

The converter topology enables regenerative energy recovery by returning absorbed energy to the grid with minimal losses. Controlled grid regeneration reduces energy consumption and cooling requirements, lowers the Total Cost of Test and increases test-stand availability. Combining the source and load in a single device also saves rack space and simplifies the test setup. Grid simulator functions can additionally reproduce realistic grid profiles.

Which Applications are Suitable for Bidirectional Power Supplies?

Bidirectional AC and DC power supplies are used wherever devices under test can both absorb and feed back energy.
DC devices are suitable for battery and energy storage testing, charge and discharge cycling, DC converters, particularly DC/DC converters, on-board chargers and 12 V or 48 V vehicle electrical systems.
Bidirectional AC devices are mainly used for grid simulation and testing inverters, PV inverters, UPS systems, chargers and grid-connected power electronics.
Depending on the device, voltage and frequency variations, grid interruptions, transients and other grid conditions can be reproduced reliably. Programmable profiles and sequences support efficiency, functional and lifetime testing.

Which Input and Output Voltage Ranges must the Device Cover?

When selecting a bidirectional power supply, both the input voltage and the required output voltage must be considered. Because the direction of energy flow can reverse, the device alternates between operating as a source and an electronic load. The required voltage range therefore depends on the device under test, the energy storage system and the specific test application.

Which Bidirectional Power Supply is Right for my Project?

Bidirectional power supplies from ITECH and KEWELL cover a wide range of power and integration requirements, from compact laboratory instruments to regenerative systems for validation and production testing.

Are you Planning a Project?

Tell us your voltage, current, power and energy requirements as well as the required quadrant operating mode. We will recommend the appropriate bidirectional AC or DC power supply, including accessories, interfaces and system integration for laboratory, validation and ATE test systems.

In summary, a bidirectional power supply enables efficient energy use.