共查询到17条相似文献,搜索用时 281 毫秒
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本文介绍了并网逆变用LCL输出滤波器的设计步骤和基干电网电压矢量定向的并网逆变系统直接电流控制方案的基本原理与推导过程,利用数字信号处理器TMS320F2812设计了一台原理样机。仿真和实验结果表明:网侧电流比逆变器侧电流高次谐波得到更好地衰减,并网电流与电网电压保持同相位,系统以单位功率因数向电网馈送电能。 相似文献
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全桥逆变器电机驱动或称开绕组结构虽然兼具相间电气隔离、容错性能好及器件开关频率低等优点,但存在逆变器输出电压矢量多、冗余严重且控制约束等问题。文中以共直流母线供电的六相全桥逆变器驱动六相永磁同步电机为研究对象,提出了一种基于二级矢量优化的简化模型预测电流控制算法,在实现电机定子基波电流有效跟踪控制的同时有效抑制了定子电流的谐波及零序分量。文中基于矢量空间解耦理论对六相全桥逆变器的输出电压矢量进行了分层分析,以定子基波电流控制、谐波及零序电流抑制为准则对逆变器输出的729个电压矢量进行二级优化,得到候选的12个电压矢量,以此为基础设计了模型预测电流控制算法。实验结果表明,该简化模型预测电流控制方法具有良好的动静态性能,能在基波电流控制的同时有效抑制谐波及零序电流分量,可为多相电机驱动系统研究提供一定的理论支撑。 相似文献
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11GHz CMOS环形压控振荡器设计 总被引:2,自引:2,他引:0
设计了一种全差分高速环形压控振荡器(VCO).该VCO有三级,每一级的增益是快慢通路增益的矢量叠加和,快慢通路的增益由底部电流源决定,差分控制电压通过镜像电流源控制快慢通路的各自电流,最终实现对振荡频率的调节.分析了VCO的工作原理及其相位噪声.电路采用TSMC公司0.18μm标准CMOS工艺制作.测试结果显示:芯片工作频率为10.88~11.72GHz,相位噪声为-101dBc/Hz@10MHz,输出信号抖动为3.8ps rms,在1.8V电源电压下的直流功耗约为75mW.该VCO可以应用于锁相环和频率合成器中. 相似文献
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设计了一种全差分高速环形压控振荡器(VCO).该VCO有三级,每一级的增益是快慢通路增益的矢量叠加和,快慢通路的增益由底部电流源决定,差分控制电压通过镜像电流源控制快慢通路的各自电流,最终实现对振荡频率的调节.分析了VCO的工作原理及其相位噪声.电路采用TSMC公司0.18μm标准CMOS工艺制作.测试结果显示:芯片工作频率为10.88~11.72GHz,相位噪声为-101dBc/Hz@10MHz,输出信号抖动为3.8ps rms,在1.8V电源电压下的直流功耗约为75mW.该VCO可以应用于锁相环和频率合成器中. 相似文献
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为了提高有源滤波器(APF)的电流跟踪性能,本文采用电压空间矢量预测电流控制方法。该方法在当前采样时刻预测下一采样时刻的指令电流,计算出APF在下一采样时刻的输出端参考电压,再利用电压空间矢量调制得出控制开关信号,以达到电流跟踪控制目的。仿真实验表明,该方法具有更好的电流控制效果。 相似文献
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针对感应电机直接转矩控制(DTC)系统启动电流过大的问题。提出一种将直流预励磁措施应用于DTC中的方法,即在零电压矢量和某一固定有效电压矢量之间进行切换,当电流超过设定值时就切换到零电压矢量。仿真和实验结果表明,该方法能有效减小启动电流,增大启动转矩,改善了DTC的性能。 相似文献
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In this paper, a novel principle for vector modulator-based phase shifters is proposed, which enables continuously adjustable phase control with only one control voltage. The weighting of the vector paths is performed by a simple configuration of DC-coupled variable attenuators. A compact low-power-consuming L-band microwave monolithic integrated circuit based on a commercial gallium-arsenide metal semiconductor field-effect transistor process is presented to verify the principle. Within a phase-control range higher than 120/spl deg/, a gain of 1.6/spl plusmn/0.6 dB is measured at 825 MHz. The current consumption is 5 mA at a supply voltage of 1.8 V. To the knowledge of the authors, this is the first vector modulator-based phase shifter which requires only one control bias, thereby significantly decreasing the control complexity. 相似文献
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矢量控制用于三相电压型PWM变流器时,能够使系统得到较好的动静态特性,但当直流侧接入非阻性负载时,直流侧电压会出现较大纹波,造成输入电流THD值增大。利用重复控制的特点,提出了一种基于矢量控制和重复控制结合的控制方法,实验结果表明,该方法有效的降低了三相电压型PWM变流器输入电流的THD值,使系统达到了更好的性能。 相似文献
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Ohishi K. Hayasaka E. Nagano T. Harakawa M. Kanmachi T. 《Industrial Electronics, IEEE Transactions on》2006,53(3):795-802
Generally, a speed servo system of a vector-controlled induction motor has limitations of motor voltage and current. When the speed servo system has a large torque reference, the output of its PI controller is often saturated. In this case, the conventional servo system stops the integral calculation of its PI controller. However, this system often has a large overshoot and/or an oscillated response caused by both a windup phenomenon and phase error on the vector control condition. This paper proposes a new speed servo system considering voltage saturation for the vector-controlled induction motor. The proposed control method compensates the phase error on vector control condition quickly, and always keeps the vector control condition. The experimental results show that the proposed system well regulates the motor speed and the secondary magnetic flux for a large torque reference without a windup phenomenon. 相似文献
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Jung-Ik Ha 《Power Electronics, IEEE Transactions on》2009,24(3):767-775
This paper presents a voltage injection method for reconstructing phase currents from current signals measured on single current-shunt circuits with cost-effective and high-performance configurations in the pulsewidth modulation (PWM) inverters that are used for digital appliances. This method involves the injection of voltage signals at the carrier frequency for reconstructing the phase currents in PWM inverters using a single current sensor in the DC-link. It uses minimum signals to reduce the voltage and current harmonics caused by the injected signals. The vector of the injected voltage is at a minimum distance from the original reference to ensure the measurement time in the reconstruction of the phase currents. An injection sequence control method is also proposed to avoid an abrupt change in the injection signals. A PWM scheme for splitting phase voltages is proposed to reduce any audible noise, especially in low-speed operation. The proposed method reconstructs the phase currents with signals from a single current sensor and minimizes the amplitude of the injected signals to reduce the harmonics at audible noise frequencies in the injection signals. Experimental results showed the effectiveness of the proposed method. 相似文献
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In a permanent magnet synchronous motor (PMSM) control system, usually, the phase voltage instruction is limited independently to prevent a three-phase pulse width modulation (PWM) wave from overflowing. This method decreases the efficiency of the bus voltage and causes voltage vector direction errors. To solve these problems, we propose a harmonic injection sinusoidal pulse-width modulation (SPWM). This method uses harmonic injected sinusoidal PWM to improve the utilisation ratio of the bus voltage, and consequently improve system performance. In this paper, we analyse the problem in terms of potential difference. The simulation results show that the proposed method can increase the utilisation ratio of the bus voltage up to 15.4%, and the voltage vector mode obtained with the proposed algorithm is larger than that obtained with the conventional one. The method with harmonic injection consequently improves current response, without affecting voltage vector accuracy. The experiment results validate the proposed method. 相似文献
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An adaptive dead-time compensation strategy for voltage source inverter fed motor drives 总被引:4,自引:0,他引:4
Urasaki N. Senjyu T. Uezato K. Funabashi T. 《Power Electronics, IEEE Transactions on》2005,20(5):1150-1160
This paper presents an adaptive dead-time compensation strategy to obtain fundamental phase voltage for inverter fed vector controlled permanent magnet synchronous motor drives. The amplitude of phase dead-time compensation voltage (DTCV) to compensate disturbance voltage due to undesirable characteristics of inverter, such as dead-time, turn-on/off time of switching devices, and on-voltages of switching devices and diodes is adaptively determined according to a dead-time compensation time (DTCT). DTCT is identified on-line with using a /spl delta/-axis disturbance voltage in the current reference frame that is synchronized with current vector. The /spl delta/-axis disturbance voltage is estimated by a disturbance observer. The accuracy of identified DTCT is experimentally confirmed by calculating the mean absolute percentage error (MAPE) between a calculated active power and a measured one. MAPE for adaptive DTCT is almost within 5% at any operating point. 相似文献
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This paper deals with the performance evaluation of space-vector-modulated matrix power converters under input and output unbalanced conditions. Two control strategies of the input current displacement angle are presented and compared in order to emphasize their influence on the input current harmonic content. The first is based on keeping the input current vector in phase with the input voltage vector. In the second, the input current displacement angle is dynamically modulated as a function of positive- and negative-sequence components of the input voltages. In both cases, the harmonic content and the three-phase RMS value of the input current have been evaluated analytically. The input current harmonic spectrum is quite different for the two control strategies and can be related to the input and output unbalance. It has been verified that, in the usual case of balanced output conditions, using the second method, it is possible to eliminate the harmonic components of the input current. Some numerical simulations are presented to confirm the analytical results 相似文献