• Proceedings of the KIEE Conference
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• 1999.11b
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• pp.375-377
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• 1999

It is necessary to obtain the high performance of the inverter system that control the output current of inverters. The dead time causes detrimental effects to the control performance of the inverter system. So we need to compensate the dead time effects. And the dead time minimization switching method can be considered as the best way to avoid the dead time effects fundamentally. In this paper, a new dead time minimization switching strategy is proposed. According to the proposed method, very short dead time is adopted in only once when the current polarity is changing. And the adopted dead time is equal to the applied dead time or shorter than it. As the proposed method can be done with the porlarity information of the reference current. it is easy to avoid some problems in comparison with the case that the real current is used to get the polarity changing time; level detection difficulty, noise problem and so on.

• Journal of Power Electronics
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• v.15 no.2
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• pp.431-442
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• 2015

Dead-time element must be set into space vector pulsed width modulation signals to avoid short circuits of the inverter. However, the dead-time element distorts the output voltage vector, which deteriorates the performance of electrical machine drive system. In this paper, dead-time effect and its compensation control strategy are analyzed. Based on the analysis, the voltage distortion caused by dead-time is regarded as two disturbances imposed on dq axes in the rotor reference frame, which degenerates the current tracking performance. To inhibit the adverse effect caused by the dead-time, a control scheme using two linear extended state observers is proposed. This method provides a strong ability to suppress dead-time effects. Simulations and experiments are conducted on a permanent magnet synchronous motor drive system to demonstrate the effectiveness of the proposed method.

• Journal of Power Electronics
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• v.16 no.2
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• pp.425-435
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• 2016

This paper presents a comprehensive theoretical analysis and an accurate calculation method of the dead-time required to achieve zero-voltage-switching (ZVS) in a battery charger with the phase-shifted full-bridge (PSFB) topology. Compared to previous studies, this is the first time that the effects of nonlinear output filter inductance, varied Miller Plateau length, and blocking capacitors have been considered. It has been found that the output filter inductance and the Miller Plateau have a significant influence on the dead-time for ZVS when the load current varies a lot in battery charger applications. In addition, the blocking capacitor, which is widely used to prevent saturation, reduces the circulating current and consequently affects the setting of the dead-time. In consideration of these effects, accurate analytical equations of the dead-time range for ZVS are deduced. Experimental results from a 1.5kW PSFB battery charger prototype shows that, with the proposed analysis, an optimal dead-time can be selected to meet the specific requirements of a system while achieving ZVS over wide load range.

• The Transactions of the Korean Institute of Power Electronics
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• v.22 no.2
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• pp.166-174
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• 2017

This study proposes a compensation method for the dead-time effects on a single-phase grid-connected inverter. Dead time should be considered in the pulse-width modulation gating signals to prevent the simultaneous conduction of switching devices, considering that a switching device has a finite switching time. Consequently, the output current of the grid-connected inverter contains odd-numbered harmonics because of the dead time and the nonlinear characteristics of the switching devices. The effects of dead time on output voltage and current are analyzed in this study. A new compensation algorithm based on second-order generalized integrator is also proposed to reduce the dead-time effect. Simulation and experimental results validate the effectiveness of the proposed compensation algorithm.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.37 no.3
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• pp.84-93
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• 2000

In PWM voltage source inverters operated by conventional switching method, the dead time is inserted in switching signals to prevent tile short circuit of the DC voltage source. The dead time causes detrimental effects to the control performance of the inverter system. So we need to compensate the dead time effects. And the dead time minimization switching method can be considered as the best way to avoid the dead time effects fundamentally. In this paper, a new switching strategy is proposed which is a kind of dead time minimization switching methods. According to the proposed switching method, very short dead time is adopted in only once when the current polarity is changing. And the adopted dead time is equal to the turn off time of the swtiching device or shorter than it. As the proposed method can be done with the polarity information of the reference current in case that the output current of the inverter is controlled, it is easy to solve some problems in comparison with the case that the real current is used to get the polarity changing time； level detection difficulty, noise problem and so on

• Journal of Power Electronics
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• v.2 no.1
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• pp.55-66
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• 2002

A new on-line dead-time compensation method for a permanent magnet (PM) synchronous motor drive is proposed. Using a simple disturbance observer without any additional circuit and off-line experimental measurement, disturbance voltages in the synchronous reference dq frame caused by the dead time and non-ideal switching characteristics of power devices are estimated in an on-line manner and fed to voltage references in order to compensate the dead-time effects. The proposed method is applied to a PM synchronous motor drive system and implemented by using software of a digital signal processor (DSP) TMS320C31. Simulations and experiments are carried out for this system and the results well demonstrate the effectiveness of the proposed method.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.155-159
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• 2001

In this paper, an on-line dead-time compensation method based on a time delay control approach is presented. The disturbance voltages caused by the dead time are estimated in an on-line manner by the time delay control without any additional circuits and off-line experimental measurements. And the estimated disturbance voltages are fed to voltage references in order to compensate the dead-time effects. The proposed method is applied to a PM synchronous motor drive system and implemented by using software of a digital signal processor (DSP) TMS320C31. Experiments are carried out for this system and the results well demonstrate the effectiveness of the proposed method.

• Journal of Power Electronics
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• v.9 no.3
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• pp.438-446
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• 2009

The performance of direct torque controlled (DTC) interior permanent magnet (IPM) machines is poor at low speeds due to a few reasons, namely limited accuracy of stator voltage acquisition and the presence of offset and drift components in the acquired signals. Due to factors such as forward voltage drop across switching devices in the three phase inverter and dead-time of the devices, the voltage across the machine terminals differ from the reference voltage vector used to estimate stator flux and electromagnetic torque. This can lead to instability of the IPM drive during low speed operation. Compensation schemes for forward voltage drops and dead-time are proposed and implemented in real-time control, resulting in improved performance of the space vector modulated DTC IPM drive, especially at low speeds. No additional hardware is required for these compensators.

• Journal of IKEEE
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• v.4 no.2 s.7
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• pp.225-232
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• 2000

Dead time which is inserted in PWM signals of VSI distorts the inverter output voltage waveforms and deteriorate the control performance of an induction machine by producing torque ripples. In this paper, dead time compensation method in a vector controlled induction machine is proposed. The method is based on a feedforward approach that compensates dead time effect by adding the compensating voltages to the inverter output voltage references in 2 phase stationary frame. The proposed method is only software intensive and easy to realize without additional hardware. The experimental results show the validity and effectiveness of the proposed method.

• Journal of Radiation Protection and Research
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• v.29 no.4
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• pp.269-273
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• 2004

The hybrid dead time model adopting paralyzable (or extendable) and non-paralyzable (or non-extendable) dead times has been introduced to extend the usable range of G-M counters in high counting rate environment and the relationship between true and observed counting rates is more accurately expressed in the hybrid model. GMSIM, dead time effects simulator, has been developed to analyze the counting statistics of G-M counters using Monte Carlo simulations. GMSIM accurately described the counting statistics of the paralyzable and non-paralyzable models. For G-M counters that follow the hybrid model, the counting statistics behaved in between two idealized models. In the future, GMSIM may be used in predicting counting statistics of three G-M dead time models, which are paralyzable, non-paralyzable and hybrid models.