共查询到18条相似文献,搜索用时 100 毫秒
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直驱式永磁同步风电机组全功率并网变流器的直流侧母线电压受网侧电网电压三相不平衡扰动,在此情况下会影响直流侧电压的稳定性。故提出应用微分跟踪器与模糊PID控制电压环策略。首先分析在电网电压不平衡条件下直流母线电压波动原理。运用微分跟踪器TD合理地提取微分信号,提取的微分信号与模糊PID控制结合控制电压外环,利用控制理论计算模糊PID参数的范围。与传统控制方式相比,加入了微分环节和模糊控制抑制了直流母线电压波动。仿真结果验证了微分跟踪器与模糊PID控制策略的有效性。 相似文献
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针对并联型有源电力滤波器的直流侧电压控制特点,提出了一种对直流侧电压进行柔性控制的并联型有源电力滤波器控制策略。该策略中,在直流侧电压控制部分引入反馈低通滤波器,削弱直流侧固有谐波对输出电流控制的影响;在电流控制的输出部分通过增加直流侧电压前馈系数,抵制在变换桥中可能引入的直流侧电压谐波影响。仿真结果表明直流侧电压柔性控制策略能够降低APF系统补偿后的电源电流总谐波畸变率,从而改善并联型有源电力滤波器的谐波补偿性能。 相似文献
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本文针对并联型有源电力滤波器(APF)的主电路及其外围电路进行了深入的研究,详细讨论了主电路开关器件的选择、缓冲电路的设计,并且采用理论分析和仿真实验相结合的方法,给出了直流母线电压的取值、直流母线电容量以及交流侧滤波电感值的选择方法。并根据上述分析方法得出了并联型APF的主电路具体器件选型及外围电路的详细设计参数。 相似文献
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A series active power filter adopting hybrid control approach 总被引:20,自引:0,他引:20
Zhaoan Wang Qun Wang Weizheng Yao Jinjun Liu 《Power Electronics, IEEE Transactions on》2001,16(3):301-310
The series active power filter (APF) is suitable for compensating a voltage type harmonics-producing load, whereas the control approach it adopts may directly influence its compensation characteristics. This paper first discusses the control approach of detecting source current in terms of the basic operation principle of a series APF, then developing a control approach of detecting load voltage. On the basis of these, a hybrid control approach is proposed. In this approach, the reference signal of the compensation voltage needed by the series APF is obtained by detecting both source current and load voltage. Thus, this approach has the advantages of the first and the second control approaches and, at the same time, it can overcome their respective drawbacks. For practical realization, the control methods of the PWM inverter in the series APF and for regulating its DC side voltage are discussed in detail. A prototype of the series APF is manufactured and corresponding experimental investigation is done. The results show that when the series APF, if adopting the hybrid control approach instead of the other two, compensates for the voltage type harmonics-producing load, its performance can be improved greatly 相似文献
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In this article, a novel DC voltage control strategy which is independent of the detection of the primary winding voltage across the series transformer is proposed to solve the DC voltage control problem of the series hybrid active power filter (APF). Meanwhile, this proposed DC voltage control method adopts an open-loop control strategy. The inverter generates unchanged DC voltage control current to ensure that the fundamental voltage loss of the series transformer remain stable. The simulation and experimental results validity and feasibility of the proposed DC voltage control the method of the series hybrid APF. 相似文献
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A novel technique is presented for generation of a contemporary estimate of the fundamental component of the distorted input current or voltage to an uncontrolled three-phase bridge rectifier with a DC link smoothing filter. This allows for accurate calculation of cancellation references for series and shunt active power filters (APF) operating under steady-state and transient conditions. Improved transient performance allows for reduction of the power rating and control system bandwidth of an APF. An artificial neural network (ANN) predictor has been used to directly calculate the mean dq-axis input to the rectifier without filtering. This is a critical stage in separating harmonic distortion from fundamental current or voltage. The technique is developed using simulation data for both series and shunt APFs and validated with experimental results. The predictive harmonic identifier shows good steady-state performance and excellent transient performance that far exceeds that of a conventional identifier using time-domain or frequency-domain filtering 相似文献
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PM2.5测量系统中改进神经网络控制算法优化补偿 总被引:1,自引:0,他引:1
针对现阶段PM2.5测量系统的测量精度较低的问题,提出了改进的BP神经网络PID控制算法对其进行优化补偿。通过对粒子群优化算法的速度公式进行了改进,采用优化的粒子群算法优化了BP神经网络,将其用于PID的在线参数调节,以PM2.5测量系统作为研究对象,将改进的BP神经网络PID控制算法与传统PID分别作了仿真研究。研究结果表明,基于改进的粒子群优化算法改进的BP神经网络PID控制算法与传统的PID控制相比,提高了测量精度,在一定程度上减少了误差。 相似文献
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PID神经元网络具有动态特性,在系统控制应用中相比于传统的PID控制方法可取得更优的效果,但其学习算法为梯度学习算法,初始权值随机取得,为了提高其控制量逼近控制目标的速度和系统响应时间,引入粒子群算法对初始权值进行优化,最后应用Matlab软件对改进后的PID神经元网络算法进行仿真。仿真结果表明,该方法具有较好的控制性能。 相似文献
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传统PID控制器在矿井提升机变频调速系统应用中,由于控制参数固定且不易整定,导致电机转速超调大、电磁转矩和转子磁链脉动大,进而出现矿井提升机调速系统控制效果差的问题。针对这一问题,文中提出一种改进粒子群优化BP神经网络PID控制器的算法。由于BP神经网络算法存在收敛速度慢和极易陷入局部最优的缺点,现将粒子群算法收敛速度快和全局最优特性与神经网络结合,并通过设计神经网络收敛系数进一步加快收敛速度。仿真结果表明,粒子群优化的神经网络控制效果比神经网络好,且效果明显优于传统PID控制器;相较于神经网络PID控制器,矿井提升机转速调节系统稳速调节速度明显提高;与传统PID控制器相比,电机电磁转矩和转子磁链脉动明显降低,具有较强的稳定性和鲁棒性。 相似文献
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文章通过对多电机同步控制的原理及其特点分析,将神经网络与PID控制相结合,设计一种神经网络PID控制器并用于多电机同步控制中,有效的缓解负载带来的同步误差,实验结果表明,在相同扰动情况下,该方法能更好的使多电机以一定速度同步运行。 相似文献