在直驱风电系统中,为了提高变流器的性能,该文提出了外环采用PI控制,内环采用无源控制的混合控制策略。根据主电路拓扑结构分别建立了在dq坐标系下的欧格-拉格朗日EL(Euler-Lagrange)模型和端口受控耗散哈密顿PCHD(port control Hamilto...在直驱风电系统中,为了提高变流器的性能,该文提出了外环采用PI控制,内环采用无源控制的混合控制策略。根据主电路拓扑结构分别建立了在dq坐标系下的欧格-拉格朗日EL(Euler-Lagrange)模型和端口受控耗散哈密顿PCHD(port control Hamiltonian with dissipation)模型。基于EL模型,采用了注入阻尼的方法,得到无源控制律;而基于PCHD模型,采用能量成形的方法,利用IDA-PBC(injecting dampingpassivity-based contro)控制算法设计无源控制器。仿真结果表明机侧变流器能够实现对转速的控制;网侧变流器实现直流电压跟踪控制、单位功率因数并网。实验验证了所提控制策略的可行性。展开更多
A device to activate lignite and sludge by electro-hydraulic impulse is presented. It comprises an impulse current generator constituted by a high voltage transformer, a high voltage silicon rectifier, a current-limit...A device to activate lignite and sludge by electro-hydraulic impulse is presented. It comprises an impulse current generator constituted by a high voltage transformer, a high voltage silicon rectifier, a current-limiting resistor, a capacitor bank and an air-break switch, and a lignite and sludge appliance made up of two plane electrodes and a working chamber. The installation activates the lignite or sludge delivered to the working chamber by the impulse current that is from the generator to puncture the main gap in the working chamber, raise the temperature therein up to (20 000 to 40 000) K and the energy density to as high as 109 Jm-3, and form a plasma piston. The alternative development and attenuation of plasma expansion makes the lignite in a number of physical and chemical processes resulting in diverse active radicals and ions, and also breaks it into grains mostly smaller than 250 mm. It is founded by experimental study that the technology can raise the content of nitro-nitrogen by 1.4 to 1.5 times and that of dissoluble organic substances by 5 to 10 times which is probably attributed to the decomposition of the ample germs in the lignite. The calculated power requirement to activate lignite is about (50 to 60) kWht-1. In comparison with muck applied to cucumber cultivation, the activated lignite demonstrates its features as an effective and economical green fertilizer by the same yield with half amount. These findings imply a promising access to green fertilizer.展开更多
文摘在直驱风电系统中,为了提高变流器的性能,该文提出了外环采用PI控制,内环采用无源控制的混合控制策略。根据主电路拓扑结构分别建立了在dq坐标系下的欧格-拉格朗日EL(Euler-Lagrange)模型和端口受控耗散哈密顿PCHD(port control Hamiltonian with dissipation)模型。基于EL模型,采用了注入阻尼的方法,得到无源控制律;而基于PCHD模型,采用能量成形的方法,利用IDA-PBC(injecting dampingpassivity-based contro)控制算法设计无源控制器。仿真结果表明机侧变流器能够实现对转速的控制;网侧变流器实现直流电压跟踪控制、单位功率因数并网。实验验证了所提控制策略的可行性。
基金the National Natural Science Foundation of China (59979029)
文摘A device to activate lignite and sludge by electro-hydraulic impulse is presented. It comprises an impulse current generator constituted by a high voltage transformer, a high voltage silicon rectifier, a current-limiting resistor, a capacitor bank and an air-break switch, and a lignite and sludge appliance made up of two plane electrodes and a working chamber. The installation activates the lignite or sludge delivered to the working chamber by the impulse current that is from the generator to puncture the main gap in the working chamber, raise the temperature therein up to (20 000 to 40 000) K and the energy density to as high as 109 Jm-3, and form a plasma piston. The alternative development and attenuation of plasma expansion makes the lignite in a number of physical and chemical processes resulting in diverse active radicals and ions, and also breaks it into grains mostly smaller than 250 mm. It is founded by experimental study that the technology can raise the content of nitro-nitrogen by 1.4 to 1.5 times and that of dissoluble organic substances by 5 to 10 times which is probably attributed to the decomposition of the ample germs in the lignite. The calculated power requirement to activate lignite is about (50 to 60) kWht-1. In comparison with muck applied to cucumber cultivation, the activated lignite demonstrates its features as an effective and economical green fertilizer by the same yield with half amount. These findings imply a promising access to green fertilizer.
