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This paper present an efficient technique and mixed-level design of programmable generating accurate reference voltage. The technique comprises a second-order error feedback Σ-Δ modulators sequence, which is then smoothed by a second-order RC filter. An FPGA-based test platform for the 10-bit programmable reference is implemented for hardware realization to verify the proposed design approach. Experimental...
One way of fully exploiting the channel capacity in multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) systems is to deploy precoding vectors derived from SVD to form parallel data pipes. Optimal precoding requires accurate channel state information for each OFDM subcarrier. This paper proposes a limited channel decomposition architecture by using an interpolation...
This article presents speed controlling for single phase induction motor. Principally, 9-level, diode-clamp inverter used to control voltages per frequency is widely used because of its high efficiency to control the motor. In this article, ARM7 model ADU7024 is used as microcontroller to generate eight pulse signals and send to the output voltage amplifier by co-connecting to the modulation module...
A switch-capacitor SDM with a controllable gain design at the signal input stage has been proposed. This gain control is realized by increasing the input sampling capacitors to obtain a higher signal gain of the first integrator. This method can greatly reduce the switch-capacitor thermal noise due to the input sampling capacitors without degrading the SDM noise shaping feature. The adaptive gain...
This paper proposes a digital implement method of selective harmonic elimination pulse width modulation (SHEPWM) based on digital signal processor (DSP). First, the switching angles for eliminating selective harmonics are calculated with computer-aided software, and functional relationships between modulation indexes and switching angles are obtained. The curve fitting technique is then used to fit...
This paper proposes a new extended boost quasi Z-source inverter (ZSI) and a simple modulation and control method based on one-cycle control for controlling a grid connected PEM fuel cell energy system. ZSIs are gaining popularity. Similarly one-cycle controllers are becoming popular due to their simplicity, ease of implementation and fast response. However, this control method has not been developed...
Ultrafast cross-phase modulation in InGaAs/AlAsSb coupled double quantum wells, where interband dispersion is modulated by intersubband excitation, is applied to a MZI switch demonstrating error-free all-optical demultiplexing of 160-Gb/s OTDM signal to 40-Gb/s.
Random carrier-frequency (RCF) modulation has been applied to DC/DC converters, reducing conducted EMI significantly. The selection of the duty cycle is critical in terms of suppressing EMI level in RCF modulation. But limited related literature is available. In this paper, we analysis the effect of duty cycle on suppressing EMI level by deduced the expression of the amplitude of switching voltage...
A novel method for directly producing QPSK modulation from baseband IQ signals is presented. The key feature of the architecture is the absence of mixers and as a result unwanted mixing products. A broadband MMIC modulator chip is demonstrated at V band to showcase the performance of the modulator. It completely covers the world wide frequency band allocation for the forthcoming 60 GHz indoor wireless...
With the increasing of the wind turbine capacity, inverter paralleling is one of the best approaches for MW-level wind power converter system design. This paper presents a new control algorithm for paralleling inverters based on SVPWM, which can reduce the output harmonic currents and inhibit the circulating current between the inverters. The detailed algorithm principles and mathematic derivations...
In this paper, an analysis is given to the topology of cascaded seven-level inverter. Then its simulation model is set up. On the other hand, several carrier control strategies are discussed, modeled and applied for the control of this multilevel inverter respectively, including phase disposition, phase opposition disposition and alternative phase opposition disposition. Then the switching control...
This paper deals with topologies of circuits and strategies of modulation for multilevel inverters. There is a close relationship between these two factors. A new Hybrid multilevel inverter based on the features of the NPC inverter and the Cascade inverter is recommended. Its three modulation strategies and voltages spectrum characteristics are analyzed. The spectrum expressions of the continuous...
PWM technology has been widely used in motor drive systems today. To avoid the short-circuit condition, dead-time must be inserted to the PWM driving pulses. The addition of dead-time increases the harmonic of output voltage, makes the waveform of winding current more badly. The ripple of motor torque and speed is also increased by the addition of dead-time. The influence of dead-time is more remarkable...
A two-phase space vector PWM (SVPWM) strategy is proposed. By properly selecting the no-switching phase in each PWM cycle, the zero current clamping phenomenon can be eliminated, and the dead-time effect can be well compensated even at zero-current periods. Two modes of the strategy are presented. RTHD mode has better harmonic distortion characteristics. In RCMV mode, the common-mode voltage (CMV),...
The multiple overlap mode of the overlap carrier wave phase shift PWM (SVPWM) inverter is one of the development directions of the super-high capacity inverter, this paper reasons the relation between carrier wave phase shift SVPWM circuit output voltage and phase shift angle, put forward the best phase shift angle formula, proposed two kinds of control schemes and compares them. Through the experiment...
This paper presents a three-level rectifier with reduced number of power switches based on one-cycle control. Only six power switches with voltage rating of half DC-link are adopted in this multilevel rectifier. A nonlinear control method, one-cycle control, is used to control the rectifier. The controller is composed of some integrators with reset, flip-flops, comparators and linear components, which...
Five-level inverter has been applied to industry and railway traction to solve the difficulty in applying low-voltage or medium-voltage switch devices to high-voltage system. The basic principle of diode-clamped five-level inverter is analysed in this paper. Based on the analysis of diode-clamped three-level inverter, single pulse control method, pulse width modulation(PWM) control methods and a novel...
This paper presents a MATLAB/Simulink simulation model for a space vector modulated matrix converter. Indirect and direct space vector modulation methods are implemented using an almost common structure, following a shared approach. Different switching strategies are simulated and analyzed for both methods. In addition, a set of rules are proposed for direct space vector modulation switching strategies...
The matrix rectifier described in this paper can realizes three-phase AC voltages to a DC output voltage and can work as a power factor correction converter. The paper presents an SPWM control strategy based on virtual DC link for AC/DC matrix rectifier with high frequency link. The matrix converter in the paper can be equivalent to a virtual rectifier and a virtual inverter. The proposed control...
Because of the unbalanced construction, the conventional three-phase three-leg inverters produce huge amount of common-mode (CM) voltage. This paper proposes a novel sinusoidal pulse width modulation (SPWM) control strategy based on three-phase four-leg structure. This strategy is an improved method on the basis of the SPWM carrier phase-shifting control technology. In the new method, the state of...
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