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pulse width modulation output

nghiên cứu kỹ thuật điều chế độ rộng xung  PWM (Pulse Width Modulation) cho bộ nghịch lưu đa bậc ghép tầng (Cascade inverter)

nghiên cứu kỹ thuật điều chế độ rộng xung PWM (Pulse Width Modulation) cho bộ nghịch lưu đa bậc ghép tầng (Cascade inverter)

Điện - Điện tử - Viễn thông

... Tóm tắt luận văn Luận văn thực nhiệm vụ nghiên cứu kỹ thuật điều chế độ rộng xung - PWM (Pulse Width Modulation) cho nghịch lưu đa bậc ghép tầng (Cascade inverter) Thông qua mô Psim đánh giá ... based PWM) Các nghịch lưu áp thường điều khiển dựa theo kỹ thuật điều chế độ rộng xung – PWM (Pulse Width Modulation) qui tắc kích đóng đối nghịch Qui tắc kích đóng đối nghịch đảm bảo dạng áp tải ... Luận Văn Tốt Nghiệp • GVHD: Ts Nguyễn Văn Nhờ Phương pháp điều chế vector không gian (Space vector modulation, Space vector PWM) • Phương pháp Discontinuous PWM Các dạng cấu trúc nghịch lưu áp đa...
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Space vector pulse width modulation for multilevel inverters and solution to modulation dependent problems

Space vector pulse width modulation for multilevel inverters and solution to modulation dependent problems

Cao đẳng - Đại học

... of Abbreviations DSP Digital Signal Processor PWM Pulse Width Modulation SPWM Sin Triangle Pulse Width Modulation SVPWM Space Vector Pulse Width Modulation CMV Common Mode Voltage NPC Neutral Point ... for Operation in Overmodulation Range 73 3.1 Introduction 74 3.2 Modulation Index and Modes of Modulation 75 3.3 Operation in Overmodulation Mode ... point fluctuation problem At low modulation index, the fluctuations can be compensated using redundant switching states But at higher modulation index and in overmodulation region, the neutral point...
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Điện tử công suât mạch MMC  Control and experiment of pulse width modulated modular multilevel converters

Điện tử công suât mạch MMC Control and experiment of pulse width modulated modular multilevel converters

Tự động hóa

... lowvoltage large-current power conversion VI C This paper has dealt with two types of pulse- widthmodulated modular multilevel converters (PWM-MMCs), proposing their control method and verifying ... the three-phase line-to-neutral u v w voltages In Fig 6, each chopper-cell is operated at unity modulation index In Table I, a unit capacitance constant H is defined as: (10) 40 ms Fig Simulated ... experiment converter, and the other is a fundamental-frequency (50 Hz) component stemming from an output frequency of 50 Hz The detailed analysis of each waveform will be carried out in the next...
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PULSE CODE MODULATION

PULSE CODE MODULATION

Hóa học - Dầu khí

... The output of the above circuit implementation is shown below in the following CRO’s figure 8A (b) Input to PCM timing The output muxed with the input is shown in figure below figure 8A (c) Output ... be implemented using the Sample and hold and Quantizer blocks The outputs is to be fed via a MUX and the input compared with the output and the error in tracing the signal is observed using a very ... distortion is shown below figure 8A (j) Distortion of the signal The final output of the decoder is shown below figure 8A (k) Output in comparision with the input C The switches in the PCM-Analog...
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Báo cáo hóa học:

Báo cáo hóa học: " Research Article Pulse Interval Modulation for Ultra-High Speed IR-UWB Communications Systems" pdf

Hóa học - Dầu khí

... only one chip where a pulse occurs and on average 4.5 empty chips, so the probability that a false pulse will be detected is higher than the probability that a correct pulse will not be detected ... Networking, vol 2008, 2008 [9] C J Mitchell, G T F de Abreu, and R Kohno, “Combined pulse shape and pulse position modulation for high data rate transmissions in ultra-wideband communications,” International ... Kaluarachchi, “Digital pulse interval modulation for optical communications,” IEEE Communications Magazine, vol 36, no 12, pp 95–99, 1998 [13] T Svedek and S Rupcic, “Anisochronous modulation methods...
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Báo cáo hóa học:

Báo cáo hóa học: " Differential Amplitude Pulse-Position Modulation for Indoor Wireless Optical Communications" pot

Báo cáo khoa học

... this paper, a novel hybrid modulation technique called differential amplitude pulse- position modulation (DAPPM) is proposed DAPPM is a combination of pulse- amplitude modulation (PAM) and DPPM The ... these techniques require more bandwidth as the maximum symbol length increases Multilevel modulation schemes were introduced in [10, 11] to achieve better bandwidth efficiency at the cost of higher ... a)7 a 12 13 11 (3) (4) DIFFERENTIAL AMPLITUDE PULSE- POSITION MODULATION DAPPM is a combination of PAM and DPPM Therefore the symbol length and pulse amplitude are varied according to the information...
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Pulse amplitude modulation

Pulse amplitude modulation

Điện - Điện tử - Viễn thông

... data symbols Introduction • Possible approaches include – Pulse width modulation (PWM) – Pulse position modulation (PPM) – Pulse amplitude modulation (PAM) • We will only be considering PAM in these ... of impulse train in transmit filter PAM • Clearly not a practical technique so – Use a practical input pulse shape, then filter to realise the desired output pulse shape – Store a sampled pulse ... k 2π T ) = T k • Substituting f=ω/2π gives the Nyquist pulse shaping criterion ∑ H( f − k T) = T k Nyquist Pulse Shaping • No pulse bandwidth less than 1/2T can satisfy the criterion, eg, T −2/Τ...
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Báo cáo y học:

Báo cáo y học: "Self-calibrating pulse contour cardiac output: do validation studies really show its clinical reliability" pps

Báo cáo khoa học

... Cavus E, Renner J, Tonner PH, Steinfath M, Scholz J, Doerges V: The reliability of pulse contour-derived cardiac output during hemorrhage and after vasopressor administration Anesth Analg 2007, ... L, Mozzo R, DeSimone P, Urbani L, Filipponi F: Evaluation of an uncalibrated arterial pulse contour cardiac output monitoring system in cirrhotic patients undergoing liver surgery Br J Anaesth ... reference standard, such as an aortic flow probe, and need to be shown to track changes in cardiac output reliably over a range of conditions Only then should human studies be performed against thermodilution,...
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biến điệu độ rộng xung pwm (pluse width modulation)

biến điệu độ rộng xung pwm (pluse width modulation)

Kĩ thuật Viễn thông

... điệu độ rộng xung pwm:(pluse width modulation) Hình 6.26: Khối biến điệu PWM Trước tiên tín hiệu s(t) lấy mẫu giữ để có s1(t) 4/5 biến điệu độ rộng xung pwm:(pluse width modulation) Tín hiệu cưa ... hợp sau gấp đôi trường hợp trước Nhưng vậy, hình 6.24 2/5 biến điệu độ rộng xung pwm:(pluse width modulation) Hình 6.24: PWM phép biến điệu phi tuyến Nếu ta giả sử tín hiệu s(t) biến đổi chậm ... biến điệu độ rộng xung pwm:(pluse width modulation) Hình 6.23: Biến điệu PWM Cũng trường hợp FM, PWM phép biến điệu phi tuyến Xem thí...
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biến điệu mã xung   pcm ( pulse code modulation )

biến điệu mã xung pcm ( pulse code modulation )

Kĩ thuật Viễn thông

... biến điệu mã xung - pcm ( pulse code modulation ) Sự lượng tử hoá làm tròn mức dùng làm bậc thang giống tín hiệu mong muốn Số mức ... khái niệm ADC Hình 7.17 biểu diễn s(t) dạng sóng PCM bit bit 2/3 biến điệu mã xung - pcm ( pulse code modulation ) Hình 7.17:PCM Mộtxung dương biểu diễn cho bit xung Zero biểu diễn bit Hoàn điệu...
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PHƯƠNG PHÁP ĐIỀU RỘNG SINGLE PUSLE WIDTH MODULATION

PHƯƠNG PHÁP ĐIỀU RỘNG SINGLE PUSLE WIDTH MODULATION

Điện - Điện tử - Viễn thông

... không vượt hai quỹ đạo tròn giới hạn Điều chế vector không gian cải biến (Modified space vector modulation) Một số tác giả đưa phương pháp điều chế vector không gian cải biến [55],[56] đó, trình...
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Báo cáo hóa học:

Báo cáo hóa học: " Research Article Combining OOK with PSM Modulation for Simple Transceiver of Orthogonal Pulse-Based TH-UWB Systems" potx

Hóa học - Dầu khí

... in a composite pulse The presence of individual orthogonal pulses in the composite pulse is decided by on-off keying, (i.e., pulse is present for one and is absent for zero) Since pulses are orthogonal, ... of 1st-, 2nd-, and 3rd-order pulses (k) where T p is the width of pulses, wn is the nth-order pulses from the kth user If all users use the same set of orthogonal pulses, n takes any value from ... one another When a pulse overlaps with itself, it is called interpulse interference (IPI) or self-interference and when pulse interferes with other pulses, it is called multipulse interference...
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Báo cáo toán học:

Báo cáo toán học: "A Combinatorial Approach to Evaluation of Reliability of the Receiver Output for BPSK Modulation with Spatial Diversit" pot

Báo cáo khoa học

... BPSK modulation is used For a large number of other modulation methods the information transmitted is more complex, and contains more than one bit However, performance analysis for these modulations ... important class consists of methods where the modulation reference (i.e a fixed numerical sequence) is transmitted on the same channel as the usual signal The demodulation decision is then based on at ... however, that one can also take into account in the demodulation process several noisy copies of these two signals: one speaks then of demodulation with diversity It appears that the probability...
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Báo cáo y học:

Báo cáo y học: "Equipment review: New techniques for cardiac output measurement – oesophageal Doppler, Fick principle using carbon dioxide, and pulse contour analysis" pot

Báo cáo khoa học

... may lead to grossly erroneous cardiac output values Validation of cardiac output measurement using oesophageal Doppler ‘Gold standard’ techniques for cardiac output measurement, such as aortic electromagnetic ... Care June 2002 Vol No Berton and Cholley Pulse contour cardiac output Figure The first attempt to determine stroke volume from the shape of the arterial pulse curve can be tracked as far back as ... better estimation of cardiac output Recalibrating every hours (or at least before any important data acquisition) may augment the accuracy of pulse contour estimated cardiac output in critically ill...
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Báo cáo y học:

Báo cáo y học: "Arterial pressure-based cardiac output in septic patients: different accuracy of pulse contour and uncalibrated pressure waveform devices" docx

Báo cáo khoa học

... and resistance) is added to the formula, which computes the pulse- contour cardiac output [7] This estimation of cardiac output from the pulse- contour analysis has been demonstrated as reliable by ... cardiac output monitoring Curr Opin Crit Care 2008, 14:322-326 Bein B, Meybohm P, Cavus E, Renner J, Tonner PH, Steinfath M, Scholz J, Doerges V: The reliability of pulse contour-derived cardiac output ... arterial pulse contour-based cardiac output device Crit Care Med 2007, 35:1904-1909 14 Mayer J, Boldt J, Schollhorn T, Rohm KD, Mengistu AM, Suttner S: Semiinvasive monitoring of cardiac output...
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Báo cáo y học:

Báo cáo y học: "Effect of norepinephrine dosage and calibration frequency on accuracy of pulse contour-derived cardiac output" pptx

Báo cáo khoa học

... -2.90-3.34 40 a nall, number of measurement pairs for pulse contour-derived cardiac output (PCCO) and transcardiopulmonary thermodilution cardiac output (COTCP); npatient, number of patients; mean, ... plots of different norepinephrine (NE) subgroups PCCO, pulse contour cardiac output; COTCP, transcardiopulmonary thermodilution cardiac output; PE, percentage error; solid line, mean bias; dotted ... care unit; MAP: mean arterial pressure; NE: norepinephrine; PCCO: pulse contour cardiac output; PE: percentage error; PP/SV: pulse pressure to stroke volume ratio; r: coefficient of correlation;...
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Báo cáo y học:

Báo cáo y học: "Endothelial Uncalibrated pulse power analysis fails to reliably measure cardiac output in patients undergoing coronary artery bypass surger" pdf

Báo cáo khoa học

... patients with thermodilution cardiac output measurements Crit Care 2006, 10:R164 Hamilton TT, Huber LM, Jessen ME: PulseCO: a less-invasive method to monitor cardiac output from arterial pressure after ... vasodilation on cardiac output measured by PulseCO J Clin Monit Comput 2007, 21:335-339 Critchley LA, Lee A, Ho AM: A critical review of the ability of continuous cardiac output monitors to measure ... mean arterial HR, heart CIPPnon-cal., cardiac index by uncalibrated pulse power analysis; CIPPcal., cardiac index by calibrated pulse power analysis; CITPTD, cardiac index by transpulmonary thermodilution;...
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Simulation of a Multiple Input Multiple Output (MIMO) wireless system

Simulation of a Multiple Input Multiple Output (MIMO) wireless system

Công nghệ thông tin

... The bandwidth of wireless communication systems is often limited by the cost of the radio spectrum required Any increase in bit rate, which can be realised without increasing the bandwidth, makes ... clever coding techniques and algorithms However, the fundamental bandwidth limitation does not change Multiple Input Multiple Output (MIMO) communication systems have been an increasingly hot topic ... – John Fitzpatrick Abstract This project explores the development of a multiple input multiple output (MIMO) simulator using ray tracing techniques This project gives an overview of ray tracing...
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