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三相电压型PWM整流器是一个强非线性系统,采用常规线性控制难以达到理想的控制效果,动态性能差且参数调节复杂。滑模控制(SMC)可有效解决非线性系统的控制问题。针对电压外环采用滑模控制而电流内环采用非滑模控制方案对PWM整流器整体动态性能和鲁棒性的影响,提出了电压外环和电流内环均采用滑模控制的双滑模控制方案。给出了双滑模控制系统的详细设计过程,并通过Matlab/Simulink搭建了系统仿真模型,对双滑模控制方案和电压外环采用滑模控制、电流内环采用PI控制方案进行对比仿真。结果表明,采用双滑模控制的PWM整流器系统不仅设计和实现简单,而且具有更优越的鲁棒性和动态性能。 相似文献
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提高重复控制逆变电源的负载瞬态响应特性 总被引:1,自引:0,他引:1
基于重复控制和PID控制方法,提出了一种重复控制和PID控制相结合的控制方法,当控制方法在稳态时采用重复控制,在非周期扰动时采用PID控制,仿真结果表明该控制方法在具有高质量的稳态波形的同时,对非周期扰动也具有很快的响应速度。 相似文献
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为改善微网逆变器性能,提出基于虚拟同步发电机(VSG)技术的模糊滑模控制(FSMC)策略。在上层控制中,采用VSG技术为底层控制提供参考电压,并为系统提供必要的惯性和阻尼;在底层控制中,采用滑模变结构控制(SMC)算法提高系统的鲁棒性和动态性,根据输出电压与参考电压的差值构成三阶滑模面,控制部分采用等效控制和切换控制;为减弱滑模变结构控制带来的“抖振”,在切换增益环节采用模糊控制算法。最后,MATLAB/Simulink仿真结果验证了所提控制策略的正确性和有效性。 相似文献
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通过对火电厂主汽压采用不同的控制信号,控制规律和平衡信号进行控制所取得的效果进行分析比较,并根据实践经验,提出针对不同的机组制粉系统和一次设备的可控性情况,采用不同的主汽压控制信号,控制规律和平衡信号的控制方案,以取得较佳的控制效果。 相似文献
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面向单相微电网的双模式并联逆变器协调控制方法 总被引:1,自引:0,他引:1
微电网中的接口变流器往往采用电压控制方法或电流控制方法。对于电压控制方法,其优点是可以应用在并网/孤岛两种模式下,然而缺点是功率控制动态响应慢。电流控制方法的优点是动态响应快,但是不能应用在孤岛模式。采用分布式电源通过两个并联逆变器接入电网的结构,与传统方法不同的是,其中一个逆变器采用电压控制,另一个逆变器采用电流控制。这种方式可以同时发挥两种控制方法的优势。与此同时,加入功率耦合环节,提高电压控制逆变器和整个系统的动态特性。单相双逆变器的仿真和实验结果证实了所提出的结构与控制方法的有效性。 相似文献
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基于模型预测控制的主动配电网电压控制 总被引:4,自引:0,他引:4
《电工技术学报》2015,(23)
为解决主动配电网中分布式可再生能源和储能系统造成的电压波动影响,基于模型预测控制理论提出了主动配电网电压调节控制策略,充分利用主动配电网中分布式电源、储能系统和有载调压变压器,实现采用最小控制成本的控制方案进行电压控制。该控制方案基于模型预测控制,采用多步滚动优化,使得电压控制过程更为灵活平滑,控制模型求解采用二次规划。通过IEEE 33节点辐射状配电网系统算例分析,证明了所提电压控制策略的可行性和有效性。 相似文献
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《电力系统及其自动化学报》2017,(11)
针对风电场中静止同步补偿器(STATCOM)数学模型的多变量、非线性和强耦合特性,提出一种非线性PI控制和前馈解耦控制相结合的STATCOM电压双闭环控制策略。在该控制策略中,STATCOM公共连接点电压和STATCOM逆变器直流侧电压的控制均采用了基于跟踪微分器的非线性PI控制,STATCOM逆变器输出电流的控制采用了前馈解耦控制。电压外环非线性PI控制提高了装置的响应速度和鲁棒性,电流内环前馈解耦控制实现了对逆变器输出电流有功分量和无功分量的解耦控制。仿真结果表明,采用所提控制策略时STATCOM在固定工况和工况发生变动的情况下均表现出了良好的控制性能,满足应用要求。 相似文献
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介绍了一种拓扑结构与众不同的矩阵变换器--间接式矩阵变换器,并将其应用于感应电机矢量控制系统.在详细介绍间接式矩阵变换器的工作原理、控制策略及换流方法的基础上,将间接式矩阵变换器与感应电机矢量控制理论相结合,提出一种新颖的感应电机矢量控制系统.该系统在实现对电机矢量控制的同时,能够实现能量的双向传递,减少电网的谐波污染,同时又可以使电网侧的双向开关在零电流时动作,无需采用四步换流策略,由此降低了控制过程的复杂性.最后,利用Matlab软件对所提系统进行仿真,仿真结果验证了该系统的可行性. 相似文献
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This article introduces a new five-level single-phase voltage source inverter. The proposed configuration employs two bidirectional switches. Since some switches share the same gate signals, the proposed circuit significantly contributed in reducing the utilized power electronics components, gate drive circuits, and system complexity. A novel space vector current control strategy was employed to maintain the desired number of voltage levels based on load current. With the proper selection of the redundant inverter switching states, the deviation in neutral-point voltage was considerably minimized. The proposed work was simulated and its hardware was manufactured. 相似文献
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Recent trends in the multi-level inverter (MLI) technology demand reduced number of switches, driver circuits, isolated DC sources, peak inverse voltage (PIV), appreciable number of voltage level, and lower total harmonic distortion. This paper presents an improved cascaded MLI configuration. Each module comprises ten switches, two isolated DC sources, and two capacitors; it can generate a maximum of 9-level output voltage waveform. Optimized switching sequence is developed that ensures minimum switching transitions and is implemented through single-carrier pulse width modulation for the control of the proposed topology. The classical cascaded H-bridge inverter and some recently developed MLI configurations were compared with the proposed inverter circuit. Results show that the proposed inverter configuration generates high number of output voltage levels with reduced number of power switches and PIV. It also has a lower per-unit power loss profile. Unit capacitor voltage balancing scheme is developed, which ensures proper control of the unit step voltage level in each of the cascaded modules, at extreme loading condition. For two cascaded inverter modules, simulation and experimental verifications are carried out on the proposed inverter for an R–L load. Simulation results of the output voltage waveforms and its harmonic spectrum are in conformity with experimental results. 相似文献
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零电压开关多谐振三电平直流变换器具有功率器件电压应力低、实现软开关范围宽、输出滤波器小的优点。该变换器的两只开关管采用相位差π脉冲频率调制的控制方式。该文将介绍交错控制方案的实现。在实际应用中由于控制电路和/或驱动电路有差异,使得两只分压电容不均压,该文提出一种均压方法,细微地调节开关管的关断时间,确保分压电容均压。论文最后给出实验结果,以验证上述方法的有效性。 相似文献
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断路器在热备用、控制回路断线在恢复时引起的重合闸误动使断路器合闸;弹簧未储能引起的重合闸多次动作重合在永久故障上;在就地分闸时,断路器重新合上;在合闸时,引起事故音响等。有的问题会引起事故或事故扩大,及运行人员误判断。通过分析和试验,在断路器控制回路逻辑上进行了简单的改造,解决了出现的问题,取得了较好的效果。 相似文献
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A high‐voltage gain nonisolated noncoupled inductor based multi‐input DC‐DC topology with reduced number of components for renewable energy systems
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Kazem Varesi Seyed Hossein Hosseini Mehran Sabahi Ebrahim Babaei 《International Journal of Circuit Theory and Applications》2018,46(3):505-518
This paper proposes a modular nonisolated noncoupled inductor‐based high‐voltage gain multi‐input DC‐DC converter. Despite the high‐voltage gain of the proposed topology, the average of normalized voltage stress (NVS) on its switches/diodes is low. This property leads to less loss and cost of switches/diodes. Using the same number of components, the proposed topology produces higher voltage gains, in comparison with recently presented high step‐up topologies. Also, the proposed topology utilizes less number of components (capacitors, inductors, diodes, and switches) for producing a desired voltage gain, which can reduce the size, mass, cost, complexity, and losses and improve the efficiency of converter. Continuous current of input sources is another main advantage of the proposed topology. All the abovementioned characteristics have made the proposed topology very suitable for renewable energy systems (or even hybrid/electric vehicles). Design considerations of the proposed topology have also been presented. For better evaluation, the proposed topology has been compared with some of recently presented high step‐up structures, from viewpoints of producible voltage gain, number of components, and normalized voltage stress (NVS) on switches/diodes. Finally, the prototype of 2‐input version has been experimentally implemented. Obtained experimental results confirm appropriate performance of the proposed topology. 相似文献