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逆变器三相输出电压在负载不平衡条件下是不对称的,为了解决负载不平衡对逆变器输出电压的影响,提出了一种改进型准比例复数积分(QPCI)控制策略,利用Bode图分析了控制器参数对系统性能的影响,对比了PI控制和改进QPCI控制对不平衡负载的抑制能力,进行了仿真与实验,验证了所提控制策略的正确性与可行性。 相似文献
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含非线性负载的三相逆变器难以建立精确的数学模型,为此,文中以三相电压型SPWM逆变器为研究对象,提出一种基于状态空间平均法的非线性负载下三相逆变器建模的方法。根据三相逆变器的工作原理建立系统的小信号模型,利用相关坐标变换及状态空间平均法导出其状态方程,对其平均变量进行分离扰动和线性化处理,经过拉普拉斯变换后得到系统的状态空间平均模型。在Matlab/Simulink环境中分别搭建系统在线性负载和非线性负载条件下的方框图模型,对于两相旋转坐标系和三相静止坐标系下的三相逆变系统进行相应的仿真。结果表明,利用状态空间平均法对三相逆变器进行建模的可行性强,且所提方法具有仿真结果精确、误差小、鲁棒性强、仿真时间短等优点。 相似文献
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为了解决常用的逆变器所带来的问题,我们提出一种新型的带升降压功能的三相DC/AC变换器拓扑,并介绍了其工作原理。借助于PSIM仿真软件,对单相和三相电路进行了仿真研究,提出了由单相组成三相电压输出的构成方法。在列出仿真参数的前提下,给出了负载电压,负载电流以及调制给定电压和逆变器输出电压的仿真结果。仿真结果表明三相DC/AC逆变器可以实现50 kHz高频功率变换下宽输入电压范围工频逆变输出,证明了理论分析的正确性。 相似文献
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本文对三相并网逆变器进行了阐述。在分布式并网发电系统中,三相并网逆变器是最为关键的部件之一。三相并网逆变器的性能主要取决于电流控制器的性能。通过对三相电压逆变器进行系统建模,经过abc三相静止坐标系下数学建模,引入dqo变换,使三相交流物理量转换为两相直流物理量。本文主要在MATLAB/SIMULINK环境中对基于模糊逻辑控制器的电流控制器进行了仿真研究。 相似文献
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分析了死区时间对逆变器输出电压谐波的影响,结合逆变器在旋转坐标系上的数学模型,提出了多旋转坐标系下死区谐波电压补偿策略,即在旋转坐标系下在线检测死区谐波电压,通过谐波电压的反馈控制对死区谐波电压进行消除。该策略无需对桥壁电流极性进行判断即能达到消除死区电压的目的。最后,在工频逆变器上通过实验验证了该补偿方法对谐波电压检测以及死区谐波电压消除的有效性。 相似文献
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介绍一种前馈加双环控制技术的逆变器,它的双环控制包括一个电容电流内环控制和一个瞬时电压外环控制。通过分析该控制策略的工作原理,应用DSP TM320F2812对控制系统进行了设计。试验结果显示逆变器有很好的正弦波输出波形,快速的动态响应,优良的负载特性和高精度的输出电压。 相似文献
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Zbigniew Rymarski 《International Journal of Electronics》2013,100(5):521-535
This article presents the complete design of a low power voltage source inverter (VSI) dedicated for a UPS system. The analysis of the rectangular PWM-AC voltage spectrum allows for a choice of the basic architecture of the inverter. Output filter parameters were calculated to reduce the maximum amplitude of the output VSI voltage harmonics for the steady-state inverter mode. The choice of the feedback loop type was based on a discussion of the inverter output impedance using a continuous model of the inverter. The parameters of the inner loop digital control for the discrete inverter model were calculated using the Coefficient Diagram Method. The influence of the step load was modelled. The time constant of the inverter closed loop system was selected to ensure sufficient system robustness. An outer feedback loop with a plug-in repetitive controller, simplified owing to the properties of the PID/CDM inner loop control, was introduced to eliminate the periodic disturbances generated by the non-linear rectifier load and the deadtime influence. The experimental verification of the design method is presented. 相似文献
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This paper describes a novel method of robust (insensitive to system parameter variations and load current changes) and fast digital control for an uninterruptible power supply (UPS) with a three-phase PWM inverter. The purpose of this paper is to propose a method by which characteristics better than those by conventional methods are obtained using an algorithm simpler than that of conventional methods. The experiments show that the purpose is achieved and the proposed method offers a total harmonic distortion of 0.6% of the output voltage waveform at a full nonlinear load. The analysis shows that the stability of the method is sufficient. Three features of the method are: (a) a capacitor current observer for stabilization and a disturbance observer for robustness are used to compensate the time lag by the computation and the disturbances, in a minor loop of the capacitor current through an inductor-capacitor filter of the inverter; (b) new models of the inverter and the disturbances are established to simplify these observers; and (c) the output voltage control loop can be designed easily and exactly because the minor loop realizes a rapid and robust control of the current 相似文献
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A three-phase voltage-source inverter for a power quality compensator under the unbalanced mains and nonlinear loads is proposed to provide balanced three-phase source current and improve input power factor. The proposed converter is based on the conventional three-phase voltage-source inverter with three additional ac power switches to achieve three-level pulsewidth modulation. The voltage stress of three ac power switches is clamped to half the dc-link voltage. The balanced reference mains currents are estimated using the dc-bus voltage and load currents. A proportional-integral voltage controller is used in the outer loop to compensate the switching losses of the voltage-source inverter. To perform the integrated power quality compensation, a hysteresis current control scheme is adopted to track the balanced line current command in phase with mains voltage. Three voltage levels are generated on the ac terminal of the proposed inverter. Computer simulation and experimental results are provided to verify the effectiveness of the proposed control scheme. 相似文献
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本文提出了一种新型的三相四线制多电平逆变器,它在常规六开关三相全桥逆变输出上,再级联一级半桥,并加入自举电路,负载中线与输入电源正极相连.在纹波跟踪分段式SPWM(Sinusoidal Pulse Width Modulation)调制下,级联的半桥电能由自举电路工作时得到.该电路拓扑结构及其控制方法,减少了多电平逆变的独立直流电源数,提高了逆变输出电压.文章用逐段计算法分析了规则采样SPWM调制法的自举电容的纹波和电流,以及产生的谐波.通过分析和实验表明,自举电容的电容量、充电回路电阻、负载和调制度等,均对自举电容的纹波和电流有影响. 相似文献
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Eung-Ho Kim Jung-Min Kwon Jae-Kyu Park Bong-Hwan Kwon 《Industrial Electronics, IEEE Transactions on》2008,55(8):2933-2942
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Parallel processing inverter system 总被引:5,自引:0,他引:5
Kawabata T. Sashida N. Yamamoto Y. Ogasawara K. Yamasaki Y. 《Power Electronics, IEEE Transactions on》1991,6(3):442-450
A novel method of instantaneous voltage and power balance control of a parallel processing inverter system is proposed. It consists of a high-speed switching PWM (pulsewidth modulated) inverter with an instantaneous current minor loop controller, a voltage major loop controller, and a power balance controller. This system realizes the following functions with only one inverter: constant AC output voltage control with reactive power control, active filtering to absorb load current harmonics, DC voltage and current control as AC-to-DC converter, and uninterruptible power supply (UPS) for stand-alone operation. This system covers a wide application range, including UPS systems, new energy systems, and active filters with voltage control functions 相似文献