Force commutated HVDC and SVC based on phase-shifted multi-converter modules

Zhang, Z.; Kuang, J.; Wang, X.; Ooi, Boon-Teck

doi:10.1109/61.216879

Cited by 105 publications

(27 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Some techniques have been suggested to build up the high voltage required for DC transmission by using multi-converters in series [35], or the use of multi-level converters ; in either case, capacitors are used to equalise the voltages across the multi-converters . The economic viability of such techniques for high-voltage applications is far from clear at present .…”

Section: Long-distance Hvdc Transmissionmentioning

confidence: 99%

Flexible AC Transmission Systems (FACTS)

Sood

2001

Power System Restructuring and Deregulation

View full text Add to dashboard Cite

Section: Long-distance Hvdc Transmissionmentioning

confidence: 99%

Flexible AC Transmission Systems (FACTS)

Sood

2001

Power System Restructuring and Deregulation

View full text Add to dashboard Cite

“…6(b) contains the amplified spect" of Fig. 6(a) together with the switching noise spectra of (5). The cancellation of the harmonics in (3) In the example of Fig.…”

Section: Mztltilevel Spwmmentioning

confidence: 98%

“…Having discovered that the higher sampling rate is an inherent requirement, the research examines next the technique of "phase shifting of the triangle carrier" applied to multiple modules of multilevel converters [5,6]. In the case of M = 8 modules, it has been found that K, = 1 triangle carrier per modulating cycle suffices in synthesizing a very good voltage waveform.…”

Section: Lntroductionmentioning

confidence: 99%

“…One method of keeping the switching rate of the GTOs low is to use multiple converter modules whose GTOs are switched in staggered intervals to create the effect of a high sampling rate. In the method which comes under the name of "triangle carrier phase shifting technique" [5,6], the effective carrier triangle number is KeR, where Kef = MKc and M is the number of converter modules.…”

Section: O P E~a T I O~ Convertementioning

confidence: 99%

“…From research on multimodules of 2-level converters connected in parallel [5] and in series [6], it has been shown that the GTOs need to switch only at 300 Hz (number of triangles per modulating cycle, K, = 5 ) provided the "phase shifting triangle carrier technique" is adopted. When M modules are employed, the equivalent triangle carrier number is Kefi = MK,.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Multimodular multilevel converters with input/output linearity

Mwinyiwiwa¹

IAS '96. Conference Record of the 1996 IEEE Industry Applications Conference Thirty-First IAS Annual Meeting

View full text Add to dashboard Cite

Absfruct: Multilevel converters constitute the key technology of power electronics to reach the high power ratings required by controllers of Hexible AC Transmission Systems (FACTS). This paper shows that the Sinusoidal Pulse Width Modulation (SPWM) technique, as applied to multilevel converters, inherently requires a high switching rate. The paper then presents a strategy based on multiple modules of multilevel converters which operate with the lowest possible switching loss (each GTO switches ON and OFF only once during the niodulation period), while maintaining the high gain-bandwidth product of linea amplifiers to handle fast feedbacks, which FACTS controllers must be capable of, in order to carry out dynamic performance enhancement. lNTRODUCTIONThe 100MVA size GTO STATCOMS which have been installed in Japan [l] and USA [2] are examples of the manufacturers' state-of-the-art in high power electronics for the electric power utility market. The GTOs are pulsed once per line frequency cycle to minimize switching loss. Real power is controlled by advancing or retarding the ac voltage phase angle. Ac voltage magnitude is controlled by increasing or decreasing the dc capacitor voltage. A high quality sinusoidal voltage waveform is synthesized by cancellations of harmonics in 8 square-wave voltages from 8 modules of GTO converters. Incidentally, in order to satisfy the high MVA required, the GTOs have to be connected in series and/or in parallel in order to augment the voltage/current ratings, so that the multimodules do not add to the cost.Anticipating the near future when GTOs can switch at a faster rate, research has already begun on sinusoidal pulse width modulated (SPWM) converters as controllers in Flexible AC Transmission Systems (FACTS) [3,4]. As SPWM-controlled converters function as linear amplifiers, they are suited to handle feedback and active filtering Signals, which are added to the line frequency ac template waveforms in the modulating signal.From research on multimodules of 2-level converters connected in parallel [5] and in series [6], it has been shown that the GTOs need to switch only at 300 Hz (number of triangles per modulating cycle, K, = 5 ) provided the "phase shifting triangle carrier technique" is adopted. When M modules are employed, the equivalent triangle carrier number is Kefi = MK,. Thus, as broad a frequency bandwidth as is required by feedback and active filtering signals, can be provided for, by the choice of M, the number of converter modules.Recently, the introduction of the multilevel converter concept [7,8] has added impetus to this line of research. The multilevel connection enables the ac voltage to be increased without transformers. The cancellation of low frequency harmonics from the ac voltages at the different levels means that the size of the ac inductances can be reduced.Up to this point in time, however, research [9-141 has shown that the Fundamental Frequency Method of switching is more promising than the SPWM method in controlling the multilevel converter. For exampl...

show abstract