High-current Insulated Gate Bipolar Transistors Research Articles

An overview of Uninterruptible Power Supply Systems

In the modern world, when there is a power outage or a power failure, telecommunication systems, computer systems, and many other critical equipment, such as medical equipment, require uninterrupted power to support their operation. Uninterruptible power supply (UPS) systems are used for this purpose. Over the years, research on UPS systems and related publications have increased. Also, new opportunities for UPS systems have emerged with the development of novel storage technologies, power electronic topologies, rapid electronic devices, high-performance digital apps, and other technological advances. Servers and storage systems, personal computers, medical equipment, telecommunication systems, and industrial equipment all require clean, stable, and uninterrupted power supply from UPS systems. Several recent studies have focused on the design of UPS systems to provide continuous power under normal or abnormal power conditions, including power outages. Such UPS systems use energy storage technologies such as batteries or flywheels to provide power to loads in the absence of applied power. Typically, static power electronics such as fast-switching high-current insulated gate bipolar transistors (IGBTs) are used to convert power. This article discusses the most typical power line issues and how they relate to the various types of UPS systems available today.

IGBT Power Stack Integrity Assessment Method for High-Power Magnet Supplies

This paper proposes a method for assessing the integrity of a series of insulated-gate bipolar transistor (IGBT) power stacks during factory-acceptance tests and service stops. The key challenge that is addressed in this paper is detecting common assembly issues that affect the power stack thermal path as well as distinguishing the acute aging effects of bond-wire lift-off and solder delamination. The method combines offline ${V_{\boldsymbol{ce}}}$ measurements with current in the extended Zero Temperature Coefficient (ZTC) operating region as well as with sensing current without modifications to the power stack. It also employs on-the-stack ${V_{\boldsymbol{ce}}} $ calibration for both the measurements. Additionally, only a fixed duty cycle pattern is needed to control the switches. The paper also presents a sensitivity analysis of the method to various parameters such as the current level in the extended ZTC operating region, the precision of the ${V_{\boldsymbol{ce}}}$ measurement, as well as the ambient, the cooling-water, and the junction temperatures. The experimental results are obtained from a high-current IGBT power stack used in a magnet power supply for particle accelerators and are compared favorably to results from finite element method and lumped parameter network simulations confirming the applicability of the method.

On <inline-formula> <tex-math notation="LaTeX">$V_{{\text{ce}}}$</tex-math> </inline-formula> Method: <italic>In Situ</italic> Temperature Estimation and Aging Detection of High-Current IGBT Modules Used in Magnet Power Supplies for Particle Accelerators

Magnet power supplies used in particle accelerators are a specialized application of power electronics that require long lifetime operation with no unscheduled interruptions and high output current precision. In this paper, the ${V_{{\rm{ce}}}} $ method with sensing current is considered for the estimation of the junction temperature and the aging detection of high-current insulated gate bipolar transistor (IGBT) modules used in this specialized application. First, sensitivity analysis of the sensing current and the gate–emitter voltage are documented to quantify their impact on the precision of the ${V_{{\rm{ce}}}} $ method for high-current modules independently of the application of interest. Two measuring circuits offering ease of calibration and reduced number of components are proposed but their applicability is not limited to this application. Their performance is tested on a 1.6 kA IGBT module that exhibits the highest current ratings documented for the ${V_{{\rm{ce}}}} $ method with sensing current. The test is carried out at a switching frequency of 6.5 kHz using an experimental set-up that emulates a phase leg of the considered power supply. The ${V_{{\rm{ce}}}} $ method with sensing current is evaluated for the aging detection of high-current IGBT modules in general and its effectiveness for the specialized application is verified experimentally.

Large Current Rectifiers: State of the Art and Future Trends

This paper presents the different technologies used in the generation of large controlled currents, in the kiloamperes range. After a brief review of processes requiring large currents, the paper discusses the working principles of thyristor phase-controlled rectifiers commonly used in these applications. Chopper-rectifiers using high-current insulated gate bipolar transistors are introduced as an alternative being considered in recent projects. The pulsewidth-modulated current-source rectifier, currently used in medium-voltage motor drives, is also analyzed as a future alternative for rectification in industrial processes. In addition, this paper presents the most important requirements and specifications to be considered in the applications of these high-power units. A system comparison is developed between thyristor and chopper-rectifiers in terms of quality of control, harmonics, power factor, losses, and efficiency.

Assessment of off-state negative gate voltage requirements for IGBTs

This paper addresses the need for off-state negative gate bias with insulated gate bipolar transistor (IGBT) devices that experience a dv/dt when in the off state. Factors considered include off-state gate bias voltage, gate impedance, reapplied dv/dt, and temperature. Theoretical calculation and experimental results for a high-voltage high-current IGBT supports the assessment of these factors.

Feedback-stabilized Nd:YLF amplifier system for generation of picosecond pulse trains of an exactly rectangular envelope

We describe the amplifier chain of the photocathode laser of the TESLA Test Facility. This chain is optimized for amplification of trains of picosecond pulses. At its output, pulse trains with a rectangularly shaped envelope of 0.7% flatness and a long-term stability of the energy in the individual picosecond pulses in excess of 0.9% are obtained. This stability is achieved by using a computerized feedback control system, which we describe in detail together with the versatile feedback algorithm applied. The feedback loop performs a tight adjustment of both the shape and magnitude of the flashlamp pulses as well as the starting time of the pump with respect to the pulse train. High-current insulated gate bipolar transistors are used to directly manipulate the flashlamp current in a microsecond time scale.

Switching voltage transient protection schemes for high-current IGBT modules

The emergence of high-current and faster switching insulated gate bipolar transistor (IGBT) modules has made it imperative for designers to look at ways of protecting these devices against detrimental switching voltage transients that are a common side effect of these efficient transistors. This paper discusses protection criteria for both normal switching operation and short-circuit operation and covers in detail some of the protection schemes that were designed to address these problems.