TRR: Application Case Analysis of Power Diodes in Industrial Control

Basic Overview
A power diode is a type of diode that can withstand high currents and voltages, mainly used in power electronic circuits. It has unidirectional conductivity and can convert alternating current into direct current, so it is widely used in rectifier circuits. The main parameters include maximum reverse voltage (V_RRM), maximum forward current (I_F), reverse recovery time (t_rr), and forward voltage drop (V_F).

classification
Ordinary power diode: mainly used in low-frequency rectification circuits, with a large forward voltage drop and slow reverse recovery time.

Fast recovery diode: It has a fast reverse recovery time and is suitable for high-frequency rectification circuits.

Schottky diode: With low forward voltage drop and extremely fast reverse recovery time, it is suitable for high-frequency and high-efficiency rectification circuits.

Ultra fast recovery diode: The reverse recovery time is shorter than that of fast recovery diodes, making it suitable for circuits with higher frequencies.

Application in Electric Motor Drive
Background introduction
In the electric motor drive system, the frequency converter is a key equipment. The frequency converter achieves precise control of motor speed and torque by controlling the frequency and voltage of the motor. Power diodes play an important role in the rectification and inverter circuits of frequency converters.

Application analysis
Rectification circuit: The input terminal of a frequency converter is usually an AC power source, which converts AC power into DC power through a rectification circuit. The use of rectifier circuits requires the ability to withstand high voltage and high current, while also requiring low forward voltage drop to reduce power consumption. Fast recovery diodes and Schottky diodes are often used in such applications due to their superior characteristics.

Inverter circuit: In an inverter circuit, power diodes are used in conjunction with power switching transistors to convert DC electricity into AC electricity. During this process, the reverse recovery characteristics of the power diode are particularly important, as a shorter reverse recovery time can reduce switching losses and improve system efficiency. Ultra fast recovery diodes are commonly used in high-frequency inverters due to their extremely short reverse recovery time.

Actual case
A large industrial enterprise has adopted a new type of frequency converter to drive electric motors in its production line upgrade. By optimizing the power diode types in the rectification and inverter circuits, the system efficiency has been significantly improved. Specific improvements include:
In rectifier circuits, using Schottky diodes instead of traditional power diodes reduces forward voltage drop and power consumption.
In the inverter circuit, the use of ultrafast recovery diodes reduces switching losses and improves the conversion efficiency and reliability of the system.

Through these improvements, the enterprise has achieved energy conservation and efficiency improvement in the electric motor drive system, saving about 10% of electricity annually, while also improving the operational stability of the equipment.

Application of Power Diode in UPS System
Background introduction
Uninterruptible power supply (UPS) systems play a crucial role in industrial and commercial fields, as they can provide backup power in the event of a power outage, ensuring the normal operation of critical equipment. Power diodes are used in the rectification, inversion, and charging circuits of UPS systems.

Application analysis
Rectification circuit: Similar to frequency converters, the rectification circuit of UPS systems also needs to convert AC power to DC power, and the selection of power diodes has a direct impact on system efficiency. Fast recovery diodes and Schottky diodes are commonly used in high-efficiency rectification circuits.

Inverter circuit: In the power supply mode, the UPS system converts the DC power provided by the battery into AC power through the inverter circuit for use by the load. During this process, the reverse recovery characteristics of the power diode are equally critical. Ultra fast recovery diodes are widely used in high-frequency inverter circuits due to their low switching losses.

Charging circuit: When the UPS system is powered by mains electricity, it needs to charge the battery. The power diode used in the charging circuit needs to have high reliability and low power consumption to ensure efficient charging and long lifespan of the battery.

Actual case
In order to improve the reliability and efficiency of its UPS system, a data center has optimized and upgraded its power diodes
In the rectification circuit, fast recovery diodes are used to improve rectification efficiency and reduce heat loss.

In the inverter circuit, ultra fast recovery diodes are used to improve the inverter efficiency and ensure stable power supply in the event of a power outage in the grid.

In the charging circuit, high reliability Schottky diodes were selected to optimize the charging process and improve the charging efficiency and lifespan of the battery.

Through these optimizations, the UPS system of the data center can provide more stable backup power in the event of a power outage, while significantly reducing system energy consumption and operating costs during normal power supply.

https://www.trrsemicon.com/diode/silicon-planar-zener-diodes-mm1z2v0.html