High Voltage IGBT Research Articles

A Novel Parallel-Connected Multiple Induction Motors Vector Control Method for the Rolling Stock Traction System

In the field of the rolling stock traction system, one inverter often drives multiple induction motors connected in parallel, because of its compactness, lightness and economical advantages. A high performance three level invereter system using high voltage and large current IGBTs that can drive multiple induction motors has been widely adopted. On the other hand, in order to provide passengers of comfortable ride feeling and to keep the train schedule even in rainy days, an accurate and responsive motor torque control is demanded. Considering this situation, we have already developed a stator-flux-oriented vector control method for the rolling stock traction system in which one inverter feeds multiple induction motors. Here, we have newly developed a novel vector control method which can improve the stability of the traction system and the motor torque response. We have also evaluated the proposed control method through stability analysis, simulations and experiments. This paper presents the principle of this control method and the mechanical and electrical models of the rolling stock traction system, as well as stability analysis, simulation and experimental results.

Recent developments of high power converters for industry and traction applications

The introduction of new high power devices like integrated gate commutated thyristors (IGCTs) and high voltage insulated gate bipolar transistors (IGBTs) accelerates the broad use of pulse width modulation (PWM) voltage source converters in industrial and traction applications. This paper summarizes the state-of-the-art of power semiconductors. The characteristics of IGCTs and high voltage IGBTs are described in detail. Both the design and loss simulations of a two level 1.14 MVA voltage source inverter and a 6 MVA three-level neutral point clamped voltage source converter with active front end enable a detailed comparison of both power semiconductors for high power PWM converters. The design and the characteristics of a commercially available IGCT neutral point clamped PWM voltage source converter for medium voltage drives are discussed. Recent developments and trends of traction converters at DC mains and AC mains are summarized.

Coaxial current transformer for test and characterization of high-power semiconductor devices under hard and soft switching

The use of a coaxial current transformer (CCT) is an interesting choice for pulsed measurement of current through power devices during switching transients. The CCT is used to reflect current for convenient external measurement with minimal insertion impedance in the critical power circuit. This paper analyzes the characteristics of the CCT and explains how it can be integrated into test setups for both press-pack and module packages. Finite-element techniques are applied to the study of the CCT to obtain detailed electrical and magnetic characteristics. Current distribution in the primary and secondary circuits, flux densities, and insertion inductance and resistance are among the design information that can be obtained through finite-element analysis. Analytical and numerical results are obtained for the proposed CCT that is integrated in test setups for MOS turn-off thyristors (press-pack) and high-voltage insulated gate bipolar transistors (module) characterization.

Power devices for medium voltage PWM converters

The accelerated pace of change in semiconductor power devices, has been remarkable, and the number of power devices described in the literature is staggering and can be bewildering to both power device specialists and power electronics equipment designers. The high-voltage insulated gate bipolar transistor and the integrated gate commutated thyristor are identified as best suited for medium-voltage pulsewidth modulated voltage source inverter stack design. These devices are examined from the viewpoint of power electronics applications.

Design and characterization of high-voltage self-clamped IGBT's

A new concept of field limiting ring (FLR) with variable ring widths is proposed for designing a high-voltage collector-gate clamped IGBT. An insulated gate bipolar transistor (IGBT) based on the concept has been designed and fabricated with a conventional IGBT process flow to provide a clamp voltage of 620 V. The dc and unclamped inductive switching (UIS) energy parameters of the IGBT are fully characterized for a temperature range of -40-150/spl deg/C. The new high-voltage self-clamped IGBT is to be primarily used in automotive ignition applications.

Study Of Oscillation In High Voltage Diode At Recovery Operation

At present, switching devices such as GCT (Gate Commutated Turn-off) thyristor and HVIGBT (High Voltage IGBT) are remarkably progressing and able to switch fast at high DC operation voltage above 2.5kV. However, a freewheeling diode which should realize the recovery performance similar to the turn-on performance of switching devices is not developed. In the high voltage diode, a main problem of the recovery performance is to prevent the voltage-oscillation. The voltage-oscillation brings miss-operation of driving circuit or voltage destruction of oneself. As the diode during the recovery operation can be regarded as a combination of one capacitance and two resistances, the oscillation mechanism was studied by replacing the diode to LCR circuit. As this results, it was clear that the diode during the recovery operation made surely the oscillation. On the basis of this analysis, the diode structure to mitigate oscillation was proposed.

Extrapolation of cosmic ray induced failures from test to field conditions for IGBT modules

Recently it was found that biased high voltage IGBTs are more vulnerable to cosmic ray failures devices like GTOs or thyristors. In order to obtain a reliable extrapolation from test to operating field conditions acceleration factors other than voltage are needed. For this purpose we exposed IGBTs and module diodes to an accelerator neutron beam and to the enhanced cosmic ray flux at 3580 m altitutde above sea level. We conclude that neutrons are the most critical particles in cosmic ways with regard to potential device failures.

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.

最新鋭ドライブシステムの動向

AC drive system has been developed to achieve the high performance and reliability. A high voltage and large capacity IGBT inverter has been launched and it widely covers applications of paper machines, winders and etc. The higher productivity and quality are required, the more important AC drive system becomes in pulp and paper industries.