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针对现有电力电子变换器潜电路分析方法存在的不足,提出了基于开关布尔矩阵分析电力电子变换器潜电路的统一方法.根据电力电子变换器的开关状态,建立变换器的开关布尔矩阵,通过布尔运算消去全开关布尔矩阵中的正常工作模态开关向量以及无效开关向量,得到变换器的潜开关布尔矩阵,进而辨识出变换器中存在的潜在开关路径和潜电路模态.以Mat... 相似文献
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《中国电机工程学报》2019,(20)
传统矩阵变换器(matrix converter,MC)模型预测电流控制策略在线寻优计算量大,适当降低采样频率有助于缓解计算压力,但会造成变换器电源侧、输出侧电流谐波大的问题。对此,该文引入开关状态切换点自由度,依据最优开关状态在最佳时刻切换的思想,提出矩阵变换器开关切换点优化预测电流控制策略。实验结果表明,所提策略与传统预测电流控制策略相比,能够有效降低矩阵变换器输出侧和电源侧电流波形中的谐波,提高矩阵变换器的电能变换质量。 相似文献
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对矩阵变换器开关器件调制策略的研究,提出了基于直接开关函数调制策略实现矩阵变换器功率器件控制信号的原理;建立了输入侧滤波器的仿真模块,以改善矩阵变换器输入侧的电流波形;建立了离散化的开关函数仿真模块,以适用于数字仿真和工程试验;建立了开关信号发生仿真模块,以实现功率器件控制信号的输出;将各个仿真模块进行组合得到矩阵变换器的整个仿真模型。然后通过Matlab/Simulink软件仿真,给出了主要的仿真波形。仿真的结果表明该矩阵变换器采用直接开关函数的调制策略是切实可行的,该调制策略不仅使功率器件控制信号的方法具有清晰易懂、简单有效的优点,而且实现了矩阵变换器良好的输入输出电气特性。 相似文献
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矩阵变换器的性能与所采用控制开关状态的调制策略有密切关系。在此介绍了一种新的矩阵变换器调制策略-占空比空间矢量调制策略。 相似文献
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针对永磁同步电机系统共模电压较大造成系统可靠性降低的问题,提出一种新型矩阵变换器(MC)直接转矩控制(DTC)策略,将传统矩阵变换器直接转矩控制开关表中部分有效矢量替换为与其方向相同或相近的旋转矢量,以此达到减小共模电压的目的.分析了矩阵变换器输出电压矢量随输入电压相角变化的规律,当有效矢量与旋转矢量的夹角在不影响控制效果的误差范围之内时,用旋转矢量将有效矢量替换,依此修改传统矩阵变换器直接转矩控制的开关表,从而得到新型矩阵变换器开关表.由于满足替换条件的旋转矢量同时存在两个,以减小开关损耗为原则,选取使开关状态变化数量较少的一个旋转矢量.对新型控制策略进行实验研究,结果表明,与传统策略相比,新型策略能够有效抑制共模电压. 相似文献
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基于系统伪故障指标截断的电力系统可靠性算法 总被引:3,自引:3,他引:0
引入了系统伪故障状态和伪故障指标的定义,并给出了系统伪故障指标的计算公式。提出了基于伪故障指标的系统状态空间截断的电力系统可靠性评估算法,利用伪故障指标包含的信息,找出所有系统伪故障状态对系统可靠性影响较大的状态集合,通过对该集合进行系统行为分析,统计计算出电力系统的可靠性指标。该算法能对系统状态空间截断,在计算速度上取得了很大的进展,协调了可靠分析中的计算速度和精度的矛盾。通过系统伪故障指标还可以分析系统的薄弱环节。 相似文献
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Iztok Fajfar Franc Bratkovic 《International Journal of Circuit Theory and Applications》1994,22(2):145-155
An efficient algorithm is given for finding all stable equilibrium states of a cellular neural network. the method is based upon a new theorem concerning the network dynamics. the theorem implies the implementation of a simple sign test which, combined with a binary tree search, efficiently performs the task of searching the equilibria. Since the proposed algorithm uses information about the network architecture and dynamic behaviour, it exhibits two important advantages over other more general methods for searching the equilibria of resistive piecewise-linear circuits. First, the regions which cannot possibly include stable steady states can be eliminated even before starting to perform the algorithm. Secondly, there is no need to solve any set of linear equations, which is usually the most tedious part of equilibrium-searching methods. 相似文献
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介绍了基于对给定函数预测的批量模糊PID控制方法在化工行业锅炉里面的应用.该方法以Fuzzy-PID算法为基础,再加上基于对给定曲线的预测提前发出控制信号,能有效地克服大时滞、非线性对控制效果的不良影响.提高控制系统的动态性能与精确性.将该方法应用到温度控制系统之中后,控制效果得到明显的改善,控制速度加快,减弱了时滞的影响. 相似文献
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V. N. Baranov L. N. Ginzburg E. R. Gorskii I. F. Romanchuk V. F. Rul’kovskii A. V. Rul’kovskii 《Thermal Engineering》2011,58(10):829-839
Results obtained from a large set of investigations, search for, and perfection of the technology for starting 200-MW two-boiler
single-turbine power units from different thermal states are presented. An algorithm for automated starting of the boiler
shell from its hot state is given as an example. 相似文献
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《Electric Power Systems Research》1998,47(3):189-195
The number of possible system contingency states can be extremely large for practical composite generation and transmission systems. It is therefore not feasible or even possible to investigate all the contingencies in adequacy evaluation of composite power systems. Only those system states which are credible or usually given as up to certain contingency level are investigated in practical calculations. Although the probabilities of the ignored high level system contingency states are individually very small, the total value can be significant as the number of these high level system states is very large, especially for large size composite systems. This paper presents a state extension algorithm, which effectively includes the effects of high level contingencies without increasing the computational effort. The algorithm can, therefore, effectively and efficiently provide improved estimates of the adequacy indices. The accuracy improvement applies to the basic failure probability, frequency and duration (F&D) indices, determined for both the overall system and the individual load points. The technique also provides exact error estimates for the three adequacy indices. The concepts associated with the technique are developed and illustrated using simple networks. A numerical example is presented in the paper to illustrate the effectiveness of the proposed algorithm. 相似文献
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Giulio Ferrari A. Asenov M. Nedjalkov C. Jacoboni 《Journal of Computational Electronics》2006,5(4):419-423
Combining an insight on the quantum transport given by the Wigner function formalism and the classical perturbation theory,
an algorithm has been developed that allows the introduction of collisional broadening in semiclassical electron transport
Monte Carlo (MC) simulations. In the proposed algorithm, electron energy and momentum are treated as independent variables;
the laws of energy and momentum conservation are fulfilled at each scattering event, but the relationship between energy and
momentum is not given by the traditional expression, since Bloch states are not eigenstates of the total Hamiltonian. The
results obtained for a simple model semiconductor demonstrate that the non-physical instabilities observed in previous attempts
to introduce collisional broadening in semiclassical MC simulations have been removed. The algorithm is suitable for application
in MC simulations of realistic device models. 相似文献
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模块化设计是提高系统可靠性、维修性,降低生产成本的一种基本方式。本文对模块化的DC/DC变换器进行了建模和仿真,在对几种常规反馈控制算法比较的基础上,提出了一种基于数字预测的非线性PID算法,仿真和实验结果表明,该控制算法的性能较常规控制算法有较大的提高。最后设计了基于DSP的系统软、硬件部分,并给出了实验结论。 相似文献
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文章提出一种改进的电网分区无功优化迭代模型和算法,将上下层电网进行更为清晰的划分,利用界面节点的电压和功率进行上下层迭代来求得全网的无功优化解。并且给出了迭代算法的收敛判据。通过在某地区电网的应用表明,分区迭代算法在优化质量、收敛可靠性和时间方面都比全网整体优化有优势。 相似文献