Bohumil Klima

High speed range field oriented control for permanent magnet synchronous motor

The paper deals with a synchronous motor control design. The field oriented control is assumed and it is suited for synchronous motor with permanent magnets. Current and voltage limitations are taken into account therefore a field weakening is used for reach high speed range with a most possible torque. A whole problem is solved using simulations in PC. Mathematical model of the synchronous motor is described in direct-quadrature reference frame. Basic electrical and mechanical equations taking into account partially saturations of magnetic circuits are used. Control methods with considered saturations, neglected saturations and without cross-coupling considering are compared.

Implementation of diagnostics functions in the IGBT drivers, part 1. — Diagnostics

The paper deals with possibilities of power IGBT transistor diagnostics directly in driver of voltage source inverters. It is necessary to implement the diagnostics circuits as close as possible to the power IGBT transistor due to high demands on drive reliability and failure predictability in many applications.

Implementation of diagnostics functions in the IGBT drivers, part 2. — HW implementation

Diagnostics methods of power inverters are usually based on using measurements of feedback electric quantities. This paper proposes ways of direct diagnostics of power semiconductors parts in its drivers. In the first part of the article, there were proposed and described methods of direct power semiconductors diagnostics for usage in voltage source inverters. Circuits for the diagnosis are assumed in power transistor driver. This paper will focus on hardware requirements, which flows from proposed solution, especially on microcontroller, control units and data collection form IGBT drivers. The description of hardware solutions for measurement of diagnostics quantities is introduced in the first part of the paper.

Intelligent IGBT driver concept for three-phase electric drive diagnostics

This document focuses on the problem of diagnostics of an electrical drive equipped with a voltage source inverter (VSI). The attention is concentrated on a hardware design for a power system diagnostics. A new concept of a power transistor driver is proposed. This concept of the driver integrates functions for monitoring of a large number of electrical drive parameters which are transferred to the superior control system for an actual operation state evaluation or an eventual failure state detection. The proposed solution introduces the possibility of an internal electrical quantities feedback realization (phase currents and DC link voltage) directly in the drivers of power transistors without using standard current and voltage sensors. The feed-backs can be extended with output voltages measurement of the inverter which can be further used in online identification of motor parameters for a model of the electrical drive. This model can be used for a control technique adaptation (with respect to maximal efficiency, maximal dynamic performance or also for sensor-less speed control or position control).

Small electric vehicle drive control according to maximal efficiency criteria

This paper deals with induction drive control implementation according to the requirement of maximal efficiency for a traction application in a small electric car. Optimum setting of the motor slip frequency was found according to the criteria of maximal motor efficiency in a wide range of torque and speed (see [1] and [2]). The traction drive is an application without any extreme dynamic response requirement. It is possible to use scalar control strategies without any significant impact on the vehicle dynamic behavior. An implementation of the optimum motor setting into a scalar control is described in this article. Optimum rotor frequency and stator current look-up tables for any operating point in the used range of desired torque and actual speed were generated and used in common induction machine scalar control schemes.

Electrical drivetrain of the small airplane and mutual interaction of this drivetrain

This paper describes conception of the drivetrain system of the full electric piloted aircraft. There are described all basic drivetrain units and their mutual interaction to achieve safety operation of the aircraft during the flight. Therefore the whole complex drive system is designed with respect to high demands on safety operation of the aircraft. There are no duplications of the basic units therefore all the units are designed with appropriate reserve margins and control systems are combined with software and hardware protections where each replace the other in case of failure.

FPGA usage for power inverters diagnostics

This article deals with FPGA usage in power inverter diagnostics. This paper proposes inverter control system design with build in diagnostics features. The base of diagnostics functions is new IGBT driver architecture with advanced measurement of transient phenomena during transistor switching on and off. The processing of measured signal is assumed in FPGA directly built in in the driver hardware. The advantage of new inverter controller architecture is continuous monitoring of inverter condition and allows watching parameter degradation during inverter life. The data obtained from diagnostics system can serve for power system failure prediction and maintenance planning. The proposed solution is expensive, but it can be useful in very high power applications such as train drives.

Battery for small electric airplane

The paper deals with an accumulator for experimental fully electric airplane VUT051RAY with rated power 55kW. The preliminary requirements on accumulator capacity and its weight were defined according to a precisely specified flight profile. The realization of the prototype of battery system is presented.

Battery System of Electric Airplane VUT 051 RAY

After assuming of all accumulator types available on the market the Panasonic NCR18650A Li-Ion accumulators were chosen. These accumulators have most advantageous capacity/weight ratio. But they have higher internal resistance in comparison with the other types of accumulators; these cells are commonly used in audio/visual equipment, office automation, notebook and handy-terminals application. Applications for land vehicles, with conclusions and data relevant for this work, were described earlier [1-2]. ECS Transactions, 40 (1) 267-273 (2012) 10.1149/1.4729113