共查询到20条相似文献,搜索用时 31 毫秒
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A quasi-parallel resonant DC-link (QPRDCL) circuit with improved PWM capability is proposed for the zero voltage switching (ZVS) three phase PWM inverter. The circuit has minimum voltage stresses and improved PWM capability due to the flexible selectability of the on/off instants of the resonant link 相似文献
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针对脉宽调制(PWM)逆变器,在研究逆变电源电压矢量的基础上,将空间矢量脉宽调制(SVPWM)技术应用于三相和单相PWM逆变电源,分别给出了三相和单相SVPWM的数字信号处理(DSP)算法,给出了一种开关模式优化的单相SVPWM算法,导出了三相和单相SVPWM基于载波调制的调制波形式以及零序信号形式,指出载波零序信号在本质上对应着逆变器零电压矢量作用时间分配与分布,论证了SVPWM与载波PWM的统一,实验结果验证了SVPWM算法的有效性. 相似文献
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针对单相全桥PWM逆变器,在研究单相逆变电源电压矢量的基础上,首次将空间矢量脉宽调制(SVPWM)技术应用于单相PWM逆变电源,并给出了单相SVPWM算法的DSP实现方法.通过对单相逆变电压调制信号的频谱分析,给出了单相SVPWM算法的谐波倍频特性;通过对单相SVPWM零电压矢量的分析,提出了一种开关模式优化的单相SVPWM算法;通过对单相SVPWM零序信号的分析,论证了单相SVPWM与载波PWM的统一.实验结果验证了单相SVPWM算法的有效性. 相似文献
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WAN YI HYO L. LlU YONG C. JUNG JUNG G. CHO GYU H. CHO 《International Journal of Electronics》2013,100(3):567-575
A soft switched space vector PWM inverter is developed using new parallel resonant DC-link (PRDCL). This PRDCL can operate on variable DC-link pulse position and width resulting in enhanced PWM capability, which is superior to other resonant DC-links. A new space vector algorithm is presented suitable for this PRDCL inverter. The suggested algorithm is able to eliminate narrow PWM pulses that impede DC-link operation. This PWM control, however, requires complex and precise timing sequences in relation to PRDCL operation, which is nicely solved by adopting a new programmed controller with a buffer and a programmable timer. 相似文献
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Yie-Tone Chen 《Power Electronics, IEEE Transactions on》1998,13(3):427-435
A new quasi-parallel resonant DC-link inverter with the more flexible pulse-width-modulation (PWM) capability and easier control is proposed in this paper. With the addition of one coupling core and one diode, the circuit can be directly applied to the single/three-phase inverter to achieve the soft-switching action. For the proposed topology, it needs neither the help of the inverter switch devices nor the requirement of voltage/current sensors. Random duration of the zero DC-link voltage can be obtained, and the voltage stresses of the inverter switches can be maintained to the minimum. The relative analysis of the presented circuit has been performed and verified by the experiment 相似文献
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A parallel resonant DC link (PRDCL) circuit topology is proposed as an approach to realizing zero switching loss DC-AC high switching frequency power conversion. The proposed circuit is used as an interface between the DC voltage supply and a voltage source pulse width modulated (PWM) inverter to provide a short zero voltage period in the DC link of the inverter to allow zero voltage switchings to take place in the PWM inverter. The peak voltage stress on the PWM inverter switches is limited to the DC supply voltage. Another significant advantage of the circuit is that the inverter can be controlled by the conventional PWM strategy. The proposed circuit is systematically analyzed and its operation principle is explained. Design considerations and design formulas are presented. A complete zero voltage switching DC-AC system consisting of the proposed circuit and a PWM inverter was simulated on a computer 相似文献
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电压空间矢量脉宽调制是一种先进的调制方法。在分析空间矢量调制(SVPWM)基本原理和输出电压特性的基础上,详细介绍了TMS320LF2407芯片产生SVPWM的硬件结构。结合电机控制专用高速数字信号处理器TMS320LF2407运算速度快、精度高、可以实时完成SVPWM控制算法的特点。给出了一种基于DSP的数字化三相感应电动机控制的软件实现方法,这种方法在三相电压源逆变器中能产生更少的谐波并减少了损耗。 相似文献
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This paper proposes a transformer-assisted pulsewidth modulation (PWM) zero-voltage switching pole inverter. As the auxiliary-resonant-commutated pole inverter (ARCPI), the proposal guarantees zero-voltage switching of the main switch and zero-current switching of the auxiliary switch, with a small power auxiliary circuit and full PWM capability. In particular, problems outstanding with the ARCPI such as control complexity, auxiliary switch protection, and center-tap potential variation, etc., are solved in the proposal. The commutation process is discussed step by step in the paper. A detailed analysis for the auxiliary circuit with regard to commutation duration/duty-cycle limitation, auxiliary switch peak current/RMS current, resonant capacitor RMS current, as well as pole output voltage loss are presented afterwards. A design methodology for the auxiliary circuit is recommended based on the analysis. The proposal is experimentally verified with a 4.25 kW half-bridge inverter prototype 相似文献
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The series-parallel resonant converter (SPRC) is known to have combined merits of the series resonant converter (SRC) and PRC. However, the SPRC has a three-element LCC structure with complex transient dynamics, and without control of the resonant circuit's dynamics, the converter's closed-loop bandwidth to switching-frequency ratio will be much reduced compared to that of pulsewidth-modulation (PWM) converters. This paper presents the optimal trajectory enabling any SPRC's steady state be achieved within one cycle. Dynamics using the state-plane analysis is presented, and the optimal state trajectory for transients is derived. Experimental results with comparison to frequency control show much reduced resonant circuit response time for step changes in output voltage. This improved resonant circuit control allows subsequent current and voltage-loop controls of the SPRC to be treated as that of a conventional PWM voltage source 相似文献
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Four-wire dynamic voltage restorer based on a three-dimensional voltage space vector PWM algorithm 总被引:3,自引:0,他引:3
Changjiang Zhan Arulampalam A. Jenkins N. 《Power Electronics, IEEE Transactions on》2003,18(4):1093-1102
A modified voltage space vector pulse-width modulated (PWM) algorithm for a four-wire dynamic voltage restorer (DVR) is described. The switching strategy based on a three-dimensional (3-D) /spl alpha//spl beta/O voltage space is applicable to the control of three-phase four-wire inverter systems such as the split-capacitor PWM inverter and the four-leg PWM inverter. In contrast to the conventional voltage space vector PWM method, it controls positive, negative and zero sequence components of the terminal voltages instantaneously. Three 3-D modulation schemes are analyzed with respect to total harmonic distortion (THD), weighted total harmonic distortion (WTHD), neutral line ripple and switching loss over the whole range of the modulation index when the DVR experiences both balanced and unbalanced sags with phase angle jumps. Experimental results from a 9 kW DVR system using a split-capacitor PWM inverter are presented to validate the simulation results. 相似文献
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This paper presents a new quasi-resonant DC-link (QRDCL) inverter. Only one switching device is used to create zero voltage instants under all load conditions. The maximum voltage across the inverter devices is maintained at around (1.01-1.1) times the input source voltage. The circuit has the flexibility of selecting switching instants of the resonant link in synchronism with any PWM technique. Control technique does not require the help of inverter switches to create the zero voltage instants in the DC-link, and voltage and current sensors are eliminated from the control circuit. In this paper, the principle of operation and detailed analysis of the proposed QRDCL inverter are presented and design considerations for achieving soft switching are obtained. Detailed PSPICE simulation studies are carried out to study the feasibility of the proposed topology under various load conditions. The experimental results of the proposed QRDCL PWM inverter feeding a three phase induction motor are given. 相似文献
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新型谐振直流环节逆变器具有PWM和软开关双重优点,然而辅助谐振直流环节有4个换能元件,使逆变器具有复杂的动力学行为和高维时变特性,用解微分方程的方法研究系统的动态特性和求解软开关条件及设计规则是相当复杂和困难的.结合相平面法分析的特点,该文将4维电路分解在3个相平面研究了系统的动力学行为、软开关条件以及设计规则.文中详细阐述了相平面的构建和分析过程,利用相平面分析结果和解析几何方法求取了软开关条件及设计规则.利用设计规则,搭建了逆变器驱动无刷直流电机的实验,实验结果验证了相平面分析的正确性和设计规则的可行性. 相似文献
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A V /f PWM inverter control algorithm based on controlling the stator flux vector of an induction motor is presented. The algorithm permits an automatic boost of inverter voltage in such a way that the stator flux magnitude is kept constant. The voltage autoboost method is based on knowledge of the IM equivalent circuit parameters and given load characteristics. An offline auto measurement of the equivalent circuit parameters using a PWM inverter is described. The technique consists of performing the no-load and single-phase tests when the motor is connected to the inverter. The complete control system has been constructed and tested and the experimental results have been found satisfactory. The proposed method has achieved a considerable improvement of IM torque-speed characteristics under optimal slip frequency operation 相似文献
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B. Gutierrez 《International Journal of Electronics》2013,100(6):913-927
This paper proposes a finite control set predictive control (FCS-PC) scheme for the shunt hybrid power filter (SHPF) to reduce the power loss while maintaining satisfactory power quality at the utility’s grid terminals. By means of the instantaneous power theory, the controller for the proposed method can generate the reference voltage for the SHPF voltage source inverter (VSI) for the future sampling time. Therefore, during a sampling time, the vector of the reference voltage is compared with the finite number of voltage vectors existent in the VSI to select the vector that best fits the cost function of the controller. The proposed method, compared with the conventional pulse width modulation (PWM) carrier method, has the capability of suppressing similarly the harmonic currents at grid terminals and controlling VSI DC-link voltage while maintaining low switching frequencies in the devices. This method shows simplicity in digital implementation because it does not need a PWM block to obtain the VSI gating signals. In addition, a comparison of the proposed FCS-PC method with the conventional carrier-based PWM method is presented and discussed. Parameter errors in the controller are studied and their effects on system performance are explained. The effectiveness of the proposed method is demonstrated with simulation and experimental results during steady-state operation and transient response of the system. 相似文献