Fast Current Control Research Articles

A high switching frequency IGBT PWM rectifier/inverter system for AC motor drives operating from single phase supply

A pulse width modulated (PWM) rectifier/inverter system using insulated gate bipolar transistors (IGBTs), capable of switching at 20 kHz is reported. The base drive circuit for the IGBT, incorporating short-circuit protection, is presented. The inverter uses an Undeland snubber together with a simple energy recovery circuit, which ensures reliable and efficient operation even for 20 kHz switching. The front end for the system is a regenerative single phase full bridge IGBT inverter along with an AC reactor. Steady-state design considerations are explained, and control techniques for unity power factor operation and fast current control of the front end power converter, in a rotating as well as a stationary reference frame, are discussed and compared. Results from computer simulations and experimental results for a 1.5 kW prototype system are presented.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

A fast variable structure current controller for an induction machine drive

Field-oriented control of a current source inverter induction machine system is essentially performed by controlling both the magnitude and orientation of the primary current vector. The interaction of the machine counter-EMF (electromotive force) and rectifier output voltage plays an important role in the current magnitude control. The traditional current loop design technique, which is suitable for DC drives, is not effective in the design of AC drivers due to this interaction. A new current loop modeling and control method is presented. This fast and robust current control technique enhances the entire system performance.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

核融合電源ハイブリッドポロイダル磁界コイル電流の非干渉高速制御方式

核融合電源ハイブリッドポロイダル磁界コイル電流の非干渉高速制御方式

A New PWM Control Method for Three-Phase Autosequentially Commutated Current Source Inverters

A new current pulsewidth modulation (PWM) method is presented which uses the principle of creating zero three-phase currents at selected instants of time, through which the load current harmonic content can be controlled along with the magnitude of its fundamental content. This gives rise to reduction of motor torque ripples through the selection of suitable PWM patterns and a fast current control in the inverter by varying the pulsewidths of the PWM pattern. Under this new PWM mode of operation, the autosequentially commutated inverter (ASCI) circuit can be modified easily so that a higher number of pulses can be accommodated within a half-cycle, compared to the normal ASCI circuit. The experimental oscillograms verify the effectiveness of the new PWM method.

Design and Experimental Results of a Brushless AC Servo Drive

High-quality electrical servo drives can only be designed and manufactured by using especially compatible and sophisticated components. A typical control actuator system is described consisting of a brushless synchronous motor and a transistor chopper inverter. Important aspects of the design and rating of a three-phase motor with rare-earth permanent magnets are pointed out. Several types of construction are described. The machine control system used is the familiar method of cascade control. By application of space vectors two special methods for fast response current control are developed. In the first case, inverter control signals are derived only from measured quantities. In the second case, the optimum controller output can be calculated if additional information about the controlled system exists. Finally, experimental results prove the excellent performance of this drive system.