Four-Quadrant System

What Is a Four-Quadrant System?

A four-quadrant system is an electrical source-and-sink system that can operate in all four quadrants of the current-voltage diagram. The quadrants are defined by the polarity of voltage and current. In two quadrants, the system delivers electrical power to the DUT; in the other two, it absorbs power from the DUT.

This makes a four-quadrant system particularly suitable for tests in which current direction, voltage polarity, or power flow can change during operation. Typical applications include battery systems, power electronics, and semiconductor devices. Certain grid simulators and Source Measure Units (SMUs) also operate on this principle. Suitable products are available in the Simulators category and the Source Measure Units (SMUs) category.

Four-quadrant operation does not automatically mean that absorbed energy is returned to the utility grid. Some devices dissipate the absorbed energy internally. A regenerative system, by contrast, can return this energy to the utility grid.

Key selection criteria include voltage, current, and power range, required dynamic performance, and the system's sourcing and sinking capabilities.