Showing papers on "PWM rectifier published in 1991"
28 Oct 1991
TL;DR: Results from an experimental study with a 1 kW hardware laboratory model of the PWM rectifier show that the dynamic response can be significantly improved even when the DC link capacitor is substantially reduced.
Abstract: The voltage-regulated pulse-width-modulated (PWM) rectifier is prone to instability. The system can be stabilized by proportional-plus-integral feedback control, but its transient response is slow. The authors describe results of a study of digital control to improve the system dynamic response by pole placement through state feedback. The control algorithm is implemented for real-time operation by using a custom-designed system of three high-speed microprocessors. Results from an experimental study with a 1 kW hardware laboratory model of the PWM rectifier show that the dynamic response can be significantly improved even when the DC link capacitor is substantially reduced. >
22 citations
TL;DR: In this paper, a stand alone, three-phase, delta-modulated, current-source PWM rectifier has been built and has been shown to be capable of operating with near sinusoidal current waveforms, unity power factor and good DC current regulation.
Abstract: A stand alone, three-phase, delta-modulated, current-source PWM rectifier has been built and has been shown to be capable of operating with near sinusoidal current waveforms, unity power factor. and good DC current regulation. A mathematical model that has been justified against experimental measurements and results from digital simulations is presented. The current waveform distortion limit and the asymptotic stability limit are established. It is shown that the rectifier can operate safely within these limits in the entire range of its power ratings. >
19 citations
28 Sep 1991
TL;DR: In this article, an uninterruptible power system (UPS) consisting of a PWM rectifier and inverter with fully digital control is presented, where the rating of the UPS is single phase 10 kVA of 200 V input and 200 V/100 V output.
Abstract: An uninterruptible power system (UPS) which consists of a pulse width modulation (PWM) rectifier and inverter with fully digital control is presented. The rating of the UPS is single phase 10 kVA of 200 V input and 200 V/100 V output. The power switching devices of the UPS are insulated gate bipolar transistors (IGBTs) in the PWM rectifier and inverter working at a switching frequency of 14.7 kHz. The instantaneous feedback control of input current and output voltage results in sinusoidal input current and output voltage. Full digital control is achieved in the control circuit of the rectifier and inverter. >
15 citations
TL;DR: In this paper, a voltage source PWM rectifier-inverter with feed-forward control of instantaneous power is described, where the instantaneous power which is calculated in the control circuit of the inverter is fed forward to the rectifier.
Abstract: In general, diode rectifiers with electrolytic capacitors on the DC side have been used as DC power supplies for voltage source inverters. This type of rectifiers, however, causes many problems such as poor power factor and harmonics. Recently, voltage source PWM rectifier-inverters have been studied to provide the following advantages; (1) harmonic-free on both AC sides; ( 2) unity power factor on the input AC side; (3) power flow of either direction or power regeneration; (4) reduction of the DC capacitor. It is, however, difficult for a conventional one to regulate the capacitor voltage on transient states because of having only a voltage feed-back loop.This paper describes a voltage source PWM rectifier-inverter with feed-forward control of instantaneous power. Based on the pq theory, the instantaneous power which is calculated in the control circuit of the inverter is fed forward to the control circuit of the rectifier. The feed-forward control of instantaneous power makes a great contribution to sufficiently suppress voltage fluctuation of the DC capacitor on transient states. Transient characteristics are discussed and some interesting experimental results of a laboratory model are shown.
8 citations
Patent•
17 Sep 1991
TL;DR: In this paper, a PLL circuit is employed to control the waveform of the AC input current to the rectifier according to a current command, regardless of the distortion of voltage waveform.
Abstract: PURPOSE:To obtain a sinusoidal input current containing no higher harmonic, even if AC input voltage to a PWM rectifier is distorted, by employing a PLL circuit when controlling the waveform of the AC input current to the rectifier according to a current command. CONSTITUTION:AC input voltage to a PWM rectifier 6 is detected at the joint of reactors 3, 5 and an R phase detection voltage is inputted to a PLL circuit 40, which then provides an output to a multiplier 12 in order to produce an R phase current command. A T phase current command is produced similarly by multiplying the output from a PLL circuit 50, which receives an AC input voltage from the PWM rectifier 6, and the output from a voltage regulator 20 at a multiplier 32. By such arrangement, AC input current to the PWM rectifier 6 can be made sinusoidal regardless of the distortion of voltage waveform.
5 citations
22 May 1991
TL;DR: In this paper, a new method for PWM (pulse width modulation) rectifier AC filter reactive component minimization is used, which uses new criteria in accordance with the recently updated IEEE Standard 519.
Abstract: A new method for PWM (pulse width modulation) rectifier AC filter reactive component minimization is used. The method uses new criteria in accordance with the recently updated IEEE Standard 519. The algorithm of the AC filter minimization procedure is given. The effects of this approach are discussed by comparison with results of a standard method. Results show that the AC filter's total kVA is reduced for a low number of pulses in the PWM pattern, while individual and total harmonic distortion are kept inside certain limits. The reduction is greater for small-sized rectifiers. >
2 citations