电网

On March 8, Toronto-listed Quadra Mining Ltd . announced that it has entered into a memorandum of understanding with China's State Grid International Development Ltd ., a wholly-owned subsidiary of the largest Chinese utility company State Grid Corp.

3月8日，在多伦多上市的企业夸德拉矿业公司宣布，该公司已与中国国家电网国际开发有限公司签订谅解备忘录，组建一家双方各占50%股权的合资公司，运营夸德拉设在智利的项目。

As part of the deal, State Grid will pay C$152m (US$148m) for a 9.9 per cent stake in Quadra.

作为协议的一部分，国家电网将出资1.52亿加元（合1.48亿美元）收购Quadra 9.9%的股份。

Management believes that the strategic JV impressively unites Quadra's skills in operating copper producing assets and State Grid's position as major end user of copper in China.

管理层人士相信，两家公司的战略性合作不仅很好地发挥了夸德拉在铜矿生产领域的先进技术，而且满足了国家电网作为中国主要铜制品终端用户的强大需求。

State Grid, China's biggest power utility, has agreed to spend at least US$900m to develop a large copper deposit in Chile in partnership with Vancouver-based Quadra Mining.

中国最大的电力公用事业公司国家电网已同意出资至少9亿美元，与总部位于温哥华的Quadra Mining携手开发智利一个大型铜矿床。

State Grid, China's biggest power utility, has agreed to spend at least US$900m (660m, 599m) to develop a large copper deposit in Chile in partnership with Vancouver-based Quadra Mining.

中国最大的电力公用事业公司国家电网已同意出资至少9亿美元，与总部位于温哥华的Quadra Mining携手开发智利一个大型铜矿床。

The phase-locked loop method of random phase angles is put forward, by which the sinusoidal quantity of random phase angles can be calculated, and phase leading can be realized and locked at random phase angles.

根据电网和普通负载的特点，提出了基于相位超前的孤岛效应检测方法，详细分析了这种方法的工作原理，最后进行了实验验证。

According to the characteristics of distribution networks,a backward topology method is adopted considering the status of the switches and the equivalent loss proportion by which the rank of calculating matrix can be reduced,and therefore it can increase the overall calculating speed.

根据配电网的结构特点，采用了计及网络开关状态的逆序拓扑方法和等效损耗分摊，以降低计算矩阵的阶数，提高整体计算速度。

Reactive component of current adds to the loads current and increases the voltage drops across network impedances.

电流的无功部分使负载电流增加并且提升了电网的阻抗压降。

The technique made full use of the characteristic of PR controller which can realize zero steady-state error in AC input signal in stationary frame. In the method, the active and reactive current component in the vector control strategy were transformed in the stationary frame to achieve the objective of keeping the DC-link voltage constant, adjusting the power factor and decoupling the active and reactive power. Compared with conventional double close-loop proportional integral controller, the PR technique is better in harmonic compensation without the complex rotating frame transformation and the couple or feedback voltage which is easily influenced by temperature and circuit parameters. The control algorithm is easy to be realized while the robustness and power quality is improved.

该方法充分利用了PR控制器能够在静止坐标系下对交流输入信号无静差控制的优势，将矢量控制策略下的有功电流和无功电流分量转换到静止坐标系下进行调节，实现网侧变换器维持直流电压稳定和调节功率因数的控制任务和双馈电机有功、无功功率的解耦控制，与传统的双闭环PI控制相比，该策略无需繁琐的坐标旋转变换，不存在受温度及电路参数影响的耦合项和前馈补偿项，且易于实现对系统低次谐波电流的补偿，减小了控制算法实现难度，提高了控制系统的鲁棒性和电网电能质量。

It is obvious that the investigation in reactive power optimization of power systems is of great significance.

从事电网无功优化规划及其优化调度的研究工作具有非常重要的意义。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。