IGBT system design strategy [Details]

Detailed explanation of IGBT system [picture and text]

IGBT, whose Chinese name is insulated gate bipolar transistor, is a device composed of MOSFET (input stage) and PNP transistor (output stage). It has the characteristics of low driving power and fast switching speed of MOSFET devices (control and response), and low saturation voltage and large capacity of bipolar devices (more durable power level). The frequency characteristics are between MOSFET and power transistor, and can work normally in the frequency range of tens of kHz.

The ideal equivalent circuit and the actual equivalent circuit are shown in the figure:

The static characteristics of IGBT are generally not used, so there is no need to consider them for now. Instead, focus on the dynamic characteristics (switching characteristics).

A simplified process of dynamic characteristics can be obtained from the following table and graph:

IGBT turn-on process

The IGBT is divided into several periods during the startup process.

1. The turn-on process is similar to that of MOSFET, and the charging time is also divided into three sections.

2. It is only in the later stage of the drain-source DS voltage drop process that a delay time is added in the process of the PNP transistor from the amplification area to the saturation.

In the table above, the following are defined: turn-on time Ton, rise time Tr and Tr.i

In addition to these two times, there is another time for the opening delay time td.on: td.on = Ton-Tr.i

IGBT is in the shutdown process

During the IGBT shutdown process, the waveform of the drain current changes into two sections.

Application of power devices in green energy-saving design [IGBT, MOSFET]

Power devices are the core devices of power electronics technology, especially IGBT modules and MOSFET devices are widely used in industrial equipment, automotive electronics, home appliances and other fields, providing help for energy saving in these fields. As the world needs energy saving, the importance of power devices will increase day by day, and the development prospects will be brighter. This special topic presents you with the latest information on power devices and energy-saving design solutions in their main application fields.

What you need to know about IGBT protection circuit design

Abstract: This paper discusses the related issues of IGBT overcurrent protection, overvoltage protection and overheat protection, and summarizes various protection methods from practical applications. These methods are highly practical and have good protection effects.

1 Introduction

IGBT (Insulated Gate Bipolar Transistor) is a new type of power electronic device that uses MOS to control transistors. It has the characteristics of high voltage, large current, high frequency, and low on-resistance, so it is widely used in the inverter circuit of the frequency converter. However, due to the poor overcurrent and overvoltage resistance of IGBT, it will be damaged once an accident occurs. For this reason, it is necessary to carry out relevant protection for IGBT. Starting from practical applications, this article summarizes the relevant issues and various protection methods of overcurrent, overvoltage and overheating protection, which is highly practical and has good application effects.

Figure 1 IGBT overcurrent detection

Technical solution for designing UPS using IGBT

The power devices used in UPS include bipolar power transistors, power MOSFETs, thyristors and IGBTs. IGBTs have the advantages of easy driving, simple control and high switching frequency of power MOSFETs, as well as the advantages of low on-state voltage and large on-state current of power transistors. The use of IGBTs has become the first choice for UPS power design. Only by fully understanding the characteristics of IGBTs and designing the circuit for reliability can the advantages of IGBTs be brought into play. This article introduces the application of IGBTs in UPS and the precautions in use.

Designing high-efficiency solar inverters using optimized high-voltage IGBTs

As the green power movement continues to gain momentum, applications including home appliances, lighting, power tools, and other industrial equipment are all trying to take advantage of the benefits of solar energy as much as possible. To effectively meet the needs of these products, power designers are converting solar energy into the required AC or DC voltage with high efficiency, with a minimum number of components, high reliability, and durability.

To produce the required AC output voltage and current for these applications with high efficiency, solar inverters require the right combination of control, driver, and output power devices. To achieve this goal, a DC to AC inverter design optimized for 500W power output and with a single-phase sinusoidal wave of 120V and 60Hz frequency is shown here. In this design, there is a DC/DC voltage converter connected to the photovoltaic panel to provide a 200V DC input to this power converter. However, the details of the solar panel are not provided here because that aspect is not the focus of our discussion.

Design of IGBT high voltage and high power drive and protection circuit

IGBT has been widely used in power electronic devices represented by inverters and various power supplies. IGBT combines the advantages of bipolar power transistors and power MOSFETs, and has the advantages of voltage control, large input impedance, low drive power, simple control circuit, low switching loss, fast on-off speed and high operating frequency.

However, like other power electronic devices, the application of IGBT also depends on circuit conditions and switching environment. Therefore, the driving and protection circuits of IGBT are the difficulties and key points of circuit design and the key links of the entire device operation.

Analysis of Several IGBT Driving Circuits in Three-Phase Inverters

The development of power electronic conversion technology has led to the rapid development of various power electronic devices. In the 1980s, in order to provide a high input impedance device for high voltage application environments, the insulated gate bipolar transistor (IGBT) was proposed [1]. In the IGBT, a MOS gate region is used to control the current transmission of a high voltage bipolar transistor with a wide base region. This produces a very attractive device that combines the high input impedance of a power MOSFET with the superior on-state characteristics of a bipolar device. It has the characteristics of low control power, fast switching speed, large current handling capacity, and low saturation voltage drop. It is currently the most common device in the design of small and medium power, low noise and high performance power supplies, inverters, uninterruptible power supplies (UPS) and AC motor speed control systems.

Practical IGBT welding power supply scheme and pipe explosion countermeasures

Practical IGBT welding power supply solution and pipe explosion countermeasures! Inverter welding machine = inverter welding Power supply + welding device. As long as the inverter welding power supply is well done, the series of products will be solved. The main problem affecting the reliability of the inverter welding power supply is "pipe explosion. In order to study "pipe explosion"!

First, analyze the composition principle of the inverter welding power supply:

It can be summarized as: one "bridge" and two "loops".

1.1 A "bridge"; the selected solutions include hard switch and soft switch circuits. The soft switch circuit with more practical value is called limited bipolar, but I think that one arm of the circuit is a soft switch, and the other arm is a harder hard switch, which is more likely to "explode the tube"! It is not easy to use in commercial machines at present!

Application of Intelligent IGBT in Automobile Ignition System

To generate a spark, the components required include a power source, a battery, a transformer (i.e., an ignition coil), and a switch to control the primary current of the transformer. Electronics textbooks tell us that V=Ldi/dt. Therefore, if the current in the primary winding of the coil changes instantaneously (i.e., the di/dt value is large), a high voltage will be generated on the primary winding. If the turns ratio of the ignition coil is N, the primary voltage can be amplified according to the turns ratio of the winding. The result is that a voltage of 10kV to 20kV will be generated on the secondary across the spark plug gap. Once this voltage exceeds the dielectric constant of the air around the gap, it will break through the gap to form a spark. This spark ignites the mixture of fuel and air, thereby generating the energy required for the engine to work (as shown in Figure 1).

Figure 1: Automobile ignition system

Reasonable selection of IGBT to improve the efficiency of solar inverter

There are countless types of advanced power components on the market today, and it is indeed a difficult task for engineers to choose the right power component for an application. For solar inverter applications, insulated gate bipolar transistors (IGBTs) can provide more benefits than other power components, including high current carrying capacity, control by voltage rather than current, and the ability to match anti-parallel diodes with IGBTs. This article will introduce how to use a full-bridge inverter topology and select the right IGBT to minimize the power consumption of solar applications.

A solar inverter is a power electronic circuit that converts the DC voltage of a solar panel into an AC voltage to drive AC loads such as household appliances, lighting, and motor tools. As shown in Figure 1, the typical architecture of a solar inverter generally uses a full-bridge topology with four switches.

Design of a driving and overcurrent protection circuit for IGBT

Insulated Gate Bipolar Transistor (IGBT) is a composite device of MOSFET and GTR. Therefore, it has the advantages of MOSFET, such as fast working speed, high switching frequency, high input impedance, simple driving circuit, and good thermal resistance, and also has many advantages of GTR, such as large current carrying capacity and high blocking voltage. It is an ideal switching device to replace GTR. IGBT is a widely used device with self-shutdown capability, which is widely used in various solid-state power supplies. The working state of IGBT directly affects the performance of the whole machine, so a reasonable driving circuit is very important to the whole machine. However, if it is not properly controlled, it is easy to be damaged. One of them is overcurrent that causes damage to IGBT. This paper mainly studies the driving and short-circuit protection of IGBT, analyzes its working principle, designs a driving circuit with overcurrent protection function, and conducts simulation research.

Application of CPLD in IGBT driver design

With the continuous development of the national economy, the application of variable frequency speed regulating devices is becoming more and more extensive. How to break the monopoly of foreign products has become a serious issue facing our engineering and technical personnel.

In a certain type of high-power variable frequency speed control device, due to the large size of the device, considering the structure and heat dissipation conditions, the PWM signal generated by the DSP on the main control board needs to travel a long distance to be sent to the IGBT inverter unit. In order to ensure the accuracy and reliability of PWM signal transmission, the following problems must be solved: First, the anti-interference problem. When the inverter is working, the switching action of the IGBT will generate high-frequency interference signals. Secondly, how to ensure the quality of the leading and trailing edges of the PWM signal and reduce the transition process of the IGBT switching action. Finally, how to reduce the wiring inductance, shorten the PWM signal transmission distance as much as possible, and avoid too many internal connections.