Classification of converters –unidirectional and bidirectional | New Topic [2024]

In this note, we are going to know about the Classification of converters – Unidirectional Converters and Bidirectional Converters. Welcome to Poly Note Hub, a leading destination for Engineering Notes.

Author Name: Arun Paul.

Classification of Converters

Converters are widely grouped into two types based on the direction of power flow: unidirectional converters and bidirectional converters.

A. Unidirectional Converters

Unidirectional converters are devices that enable power to flow in just one direction: either from input to output or from output to input, but not both at once. They are typically utilized in systems where power flow is primarily in one direction.

Some examples of unidirectional converters are –

1. Rectifiers: These convert alternating current (AC) to direct current (DC), allowing power to flow from the AC input to the DC output.
2. Inverters: These convert DC to AC, enabling power flow from the DC input to the AC output.
3. DC-DC Converters: These convert DC voltage from one level to another, typically used for voltage regulation or step-up/step-down purposes.

B. Bidirectional Converters

Bidirectional converters are devices that can transfer power in both directions, allowing energy to be exchanged between two systems or components. They are often used in applications that need bidirectional power flow, such as energy storage systems, electric vehicle charging stations, and renewable energy integration.

Examples of bidirectional converters are –

1. Bi-directional DC-DC Converters: These converters are capable of regulating and controlling the bidirectional flow of power between two DC sources or loads. They are frequently utilised in applications like as hybrid electric vehicles (HEVs), battery energy storage systems (BESS), and renewable energy systems.
2. Bidirectional Inverters: These inverters convert DC electricity to AC and vice versa, allowing power to flow in both directions. They play an important role in systems such as grid-tied inverters for solar PV systems, which allow surplus energy to be fed back into the grid, and vehicle-to-grid (V2G) systems, which allow electric vehicles to charge and discharge to the grid.

The particular needs of the application, such as the directionality of power flow, efficiency considerations, and system integration requirements, will determine which unidirectional or bidirectional converter is best.