Operation of Naturally Sampled Current Regulators in the Transition Mode

Rowan, T.M.; Kerkman, R.J.; Lipo, T.Α.

doi:10.1109/tia.1987.4504955

Cited by 69 publications

(17 citation statements)

References 8 publications

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“…3 with pulse width modulation, involving the direct comparison of u T auxiliary signal with the output of the current controller u r (double-edge naturally sampled PWM [27], Fig.4a), the critical gain K r,cr can be determined by comparing the slew rate of the two signals:…”

Section: Current Control System With Double-edge Naturally Sampled Pwmmentioning

confidence: 99%

Current control with asymmetrical regular sampled pulse width modulator applied in parallel active filter

Płatek

Osypiński²

2016

Bulletin of the Polish Academy of Sciences Technical Sciences

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Abstract. This paper presents an analysis of the properties of pulse width modulator with a single (symmetrical regular sampled PWM) and double (asymmetrical regular sampled PWM) control sampling of the input signal (low-frequency control input wave) in presence of a triangular auxiliary signal. In this paper, a comparison of the characteristics of these modulators used in the control system with a linear proportional controller is presented. The article provides the relations derived for the maximum amplification of regulators for which the control system operates stably. Analysis results have been confirmed by simulation and experimental studies of a commercial active filter installed in an industrial plant. Simulation studies show an increase of the critical proportional controller gain with symmetrical regular sampled PWM with a doubled number of samples in the period of the triangular auxiliary signal for which the control system is stable. Also, the analysis included in this article demonstrates the possibility of increasing the value of the gain of the proportional controller in a closed system with asymmetrical regular sampled PWM. Publications [8][9][10][11][12][13][14] devoted to applications in power electronics systems with the asymmetrical regular sampled PWM are not related to control systems with a proportional controller. From the point of view of the topics covered in this article, the most interesting paper is publication [15]. This paper addresses the digital control system with asymmetrical regular sampled PWM with different types of controllers, but the issues critical to the gain of the proportional controller addressed in the present article are not discussed.One of the objectives of the work presented is to compare the dynamic and static properties of the control system with a proportional controller and symmetrical regular sampled or asymmetrical regular sampled PWM.Carried out in this article is an analysis taking into account the time between the instant of measurement of the controlled value and the actual determination of the magnitude of the sampled reference (PWM computation delay [15]).Control system with proportional controller has non-zero value of disturbance error. From the point of view of minimizing the disturbance errors and the reducing the time of decay of transient component of this error advantages of asymmetrical regular sampled PWM compared to the symmetrical regular sampled PWM manifest themselves only under the condition of an appropriately small value of the PWM computation delay.The article also describes a mechanism allowing for elimination of the impact of this error on the output current of the APF. This is a feature of APF with supervisory system of DC link voltage which allows the use of output current proportional controller.

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Section: Current Control System With Double-edge Naturally Sampled Pwmmentioning

confidence: 99%

Current control with asymmetrical regular sampled pulse width modulator applied in parallel active filter

Płatek

Osypiński²

2016

Bulletin of the Polish Academy of Sciences Technical Sciences

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“…Utilizing the modulation index definition, general formulas can be derived independent of the inverter voltage. Except for the SPWM method, the voltage-gain formulas of the carrier-based PWM methods have not been reported, nor has a detailed gain characteristic study been conducted [4], [16]. In the following, the gain formulas of the discussed modulators are derived, and a comparative evaluation follows.…”

Section: Overmodulation Range Voltage-gain Characteristicsmentioning

confidence: 99%

“…Also, a drive with high-performance overmodulation range operating capability is less sensitive to inverter dc-bus voltage sag, which often occurs in diode-rectifier front-end-type drives due to acline voltage sag or fault conditions, hence, increased drive reliability. Recently, overmodulation issues have attracted the attention of many researchers, and overmodulation strategies for the two popular methods-SPWM [3], [4] and space-vector PWM (SVPWM) [5], [6]-have been developed. However, the overmodulation characteristics of many other carrier-based PWM methods have not been explored, nor has a comparative study been reported.…”

mentioning

confidence: 99%

Carrier-based PWM-VSI overmodulation strategies: analysis, comparison, and design

Hava¹,

Kerkman

Lipo

1998

IEEE Trans. Power Electron.

371

171

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In this paper, the overmodulation region voltagegain characteristics and waveform quality of carrier-based pulsewidth-modulated (PWM) methods are investigated. Through detailed analytical study, voltage-gain characteristics are extracted independent of carrier frequency. The influence of blanking time and minimum pulsewidth (MPW) control on the inverter gain characteristics are studied and shown to be significant. A comparative evaluation of the modulator characteristics reveals the advantageous high-modulationrange characteristics of discontinuous PWM methods and, in particular, the superior overmodulation performance of a discontinuous PWM method. The modulation methods under consideration are tested on a PWM voltage-source inverter (VSI)-fed induction motor drive in the laboratory, and the theoretical results are verified by experiments. Also, a gain linearization technique is presented and experimentally verified. The results of this study are useful in design, performance prediction, and development of high-performance overmodulation strategies for PWM-VSI drives.

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“…Calculated by projecting the tip point of the reference voltage vector on the hexagon side (point b in Fig. 7), the analytical angle relation of MMEPWM yields the following formula: (8) Although (7) and (8) are different in form, their numerical evaluation which is shown in Fig. 9 reveals the fact that their performance is the same.…”

Section: Triangle Intersection Pwm Dynamicmentioning

confidence: 99%

“…Furthermore, the inverter output voltage contains substantial subcarrier frequency harmonics, and drive performance degrades considerably [6]. The overmodulation range fundamental component voltage gain and waveform quality characteristics of the modern PWM methods, which are important for open-loop (constant volts per hertz) controlled ac motor drives, are well understood [6]- [8].…”

Section: Introductionmentioning

confidence: 99%