What is the difference between isolated power converter and non isolated power converter

In the field of power electronics, the type and design of power sources directly affect the performance, safety, and reliability of equipment. Isolated power supply and non isolated power supply, as two common types of power supply, have significant differences in structure, working principle, application scenarios, and performance characteristics. This article will provide a detailed comparison and analysis of these two types of power supplies, in order to provide reference for power supply design and application.

2、 Definition and Overview

Isolation power supply

Isolated power supply refers to a power system that has electrical isolation between input and output. It provides electrical isolation between the input circuit and the output circuit by using devices such as transformers or isolation switches, cutting off the direct current path between the input and output circuits. The main feature of isolated power supply is that there is no electrical connection or shared common ground wire between the input and output, providing higher insulation and safety.

Non isolated power supply

Non isolated power supply refers to a power system that does not have direct electrical isolation between input and output. The input circuit and output circuit share the same ground wire or connection, without physical insulation isolation. Non isolated power supplies typically use electronic components such as transformers, rectifiers, and regulators to convert input voltage into the desired output voltage.

3、 Structure and Working Principle

Isolation power supply

The structure of an isolated power supply typically includes input circuits, transformers, output circuits, and feedback control circuits. Its working principle is to achieve electrical isolation between input and output through a transformer. The input circuit sends the voltage provided by the mains or other power sources into the transformer, which converts the input voltage to the required voltage level and transfers the current to the load through the output terminal. The insulation layer of the transformer protects the electrical connection between the input and output, thereby achieving isolation.

Non isolated power supply

The structure of non isolated power supplies is relatively simple, usually including input circuits, conversion circuits, output circuits, and protection circuits. Its working principle is to directly convert the input voltage into the desired output voltage, usually achieved using appropriate electronic components (such as transformers, rectifiers, regulators, etc.) as well as filtering and control circuits. Due to the lack of electrical isolation, the input and output of non isolated power sources share the same ground wire or connection.

4、 Performance characteristics and advantages/disadvantages

Isolation power supply

advantage:

High safety: Due to the lack of electrical connections or shared common ground wires between input and output, isolated power sources provide higher insulation and safety, reducing the risk of electric shock and electric shock.

Strong anti-interference ability: Due to the existence of electrical isolation, isolated power supplies can effectively isolate noise and interference signals between input and output, improving the stability and reliability of equipment.

Good voltage resistance: The isolated power supply has high voltage resistance and can withstand high voltage fluctuations and impacts.

Disadvantages:

High cost: Due to the need for isolation devices such as transformers and corresponding control and protection circuits, the cost of isolating the power supply is relatively high.

Large volume: Due to the complex structure and the need to meet certain electrical isolation requirements, the volume of isolated power sources is usually large.

Non isolated power supply

advantage:

Low cost: Non isolated power supplies use simple circuit structures and electronic components, resulting in relatively low costs.

Compact size: Due to the lack of electrical isolation requirements, non isolated power supplies are usually smaller in size, making them easier to integrate and install.

High conversion efficiency: Non isolated power supplies typically use efficient electronic components and circuit structures, which can achieve high conversion efficiency.

Disadvantages:

Low safety: Due to the lack of electrical isolation between input and output, non isolated power supplies have relatively low safety and are susceptible to noise and interference signals.

Poor voltage resistance: Non isolated power supplies have relatively poor voltage resistance and limited ability to withstand voltage fluctuations and shocks.

5、 Application scenarios

Isolation power supply

Isolated power supplies are widely used in applications that require high electrical isolation and safety, such as medical equipment, industrial control systems, high-precision instruments, etc. In these applications, isolated power sources can effectively protect equipment and personnel from electric shock and the hazards of electric shock, improving the stability and reliability of equipment.

Non isolated power supply

Non isolated power supplies are widely used in consumer electronics, computer equipment, household appliances, and other fields. Due to the relatively low requirements for electrical isolation and strict requirements for cost and volume, non isolated power supplies have become a more suitable choice for these devices.

6、 Conclusion

In summary, there are significant differences between isolated and non isolated power supplies in terms of structure, working principle, performance characteristics, and application scenarios. When choosing the type of power supply, it is necessary to consider the specific application requirements and safety requirements comprehensively. For situations that require high electrical isolation and safety, isolated power sources should be selected; For situations with high requirements for cost, volume, and conversion efficiency, non isolated power sources can be chosen.