A Current-Source-Converter-Based High-Power High-Speed PMSM Drive With 420-Hz Switching Frequency

Abstract

In this paper, a current-source-converter (CSC)-based high-power high-speed (HPHS) permanent-magnet synchronous motor drive is proposed for high-speed compressor applications. The most important feature of the proposed CSC-fed HPHS drive is that the switching frequency is limited to 420 Hz at 200-Hz fundamental frequency. In the drive system, the whole operation range is divided into three regions, namely, the high-, medium-, and low-speed regions, where different modulation strategies and control schemes are used with the requirement of switching frequency and output filter. In particular, a two-pulse space vector modulation with dynamic capacitor voltage control is proposed for the high-speed region to achieve better dynamic and harmonic performance. Both simulation and experiments verify the proposed control strategy.Index Terms-Current-source converter (CSC), high power, high-speed drive, LC resonance.

On Dynamic Models and Stability Analysis of Three-Phase Phasor PWM-Based CSI for Stand-Alone Applications

“…A CSI is operated using either Selected Harmonic Elimination (SHE) switching pattern or Space Vector PWM (SVPWM) switching pattern, the latter is formulated based online currents [15] - [21]. In the SHE switching technique, shoot-through (charging) states are prevented.…”

Tunable Ultracapacitor

“…10 were all taken at the maximum capacitance of the prototype (4.11 F). To perform these measurements, the ultracapacitor was inserted in a simple square-wave oscillator circuit (based on the Schmitt trigger), and the discharge voltage given by (9) was observed on the oscilloscope. The frequency of operation of the oscillator circuit was controlled with a variable resistor, which also determines the time constant of the discharge.…”

“…The voltage between the terminals of the ultracapacitor was measured with a Keithley electrometer (model 610C), which has an input impedance of 10 14 Ω and therefore does not disturb or alter the internal leakage resistance of the ultracapacitor. By using (9), where the only resistance that is assumed to be present is the internal leakage resistance, the self (or internal) time constant of the ultracapacitor was calculated. Since the capacitance C is known (4.11 F), the internal leakage resistance was calculated to be approximately 270 kΩ.…”

“…Such applications include: ultrawideband filtering and radio transceiver applications, oscillators with very large dynamic range, high-sensitivity electromechanical transducers, etc. [5]- [9]. At present, conventional variable air capacitors are used in such applications.…”

Control strategies of current-source inverters for distributed generation under unbalanced grid conditions

“…Most of previous research work of DG system under faulty grid voltages are focused on the voltage source inverter (VSI) based grid converters [2]. Differently, the current source inverter (CSI) offers the merits of simple configuration and PWM strategy, low dv/dt, high fault-current tolerant capability, etc [3][4][5]. The CSI has been widely used in the medium-voltage high-power drive systems.…”