当前迫切需要研究实现可再生能源与电网统一协调发展的能源互联网系统提供技术支撑.通过提出扩展的能源枢纽模型,基于考虑了太阳能光伏发电和可再生能源发电储能技术的参与.分析日常负载需求(例如电、热和冷却)和使用时间能源价格来设置优化问题.为了优化总能源成本,构建了一个数学模型,其中包括一些约束,例如能源枢纽的输入输出能量平衡,电价,系统的容量限制以及可再生能源发电技术的储能效率.比较了基于不同能源枢纽结构的运营案例,以评估太阳能应用和电池储能系统、可再生能源发电技术对运营效率的影响.结果表明,所提出的模型预测了电力和天然气的所需量的重大变化,从而导致总成本降低.

Recently, inductive energy storage systems have attracted interests due to high energy densities. The high-temperature superconducting pulsed-power supply (HTSPPS) is one inductive PS topology for electromagnetic launching system. The topology can achieve a high amplitude load current and cut down the electrical losses due to the zero resistance characteristic of superconducting inductors. However, in this topology, the integrated gated commuted thyristor is used as a switch and cannot withstand high current, which limits the expansion of the system. Besides, it has significant current amplification ability as a single unit, but one module cannot provide sufficient amplitude and appropriate pulsewidth for the load current of the electromagnetic launching. In this paper, by applying the principle of inverse current commutation with semiconductor devices (ICCOS) in the HTSPPS, a novel circuit topology called HTSPPS with ICCOS is presented. This topology is analyzed and the multiple modules system is established. Simulation results show that the HTSPPS with ICCOS exceeds the current limitations of the original one and ensures the reliable cutting off of the main switch. It has potential applications in the future of high-energy systems while reducing the cost greatly. By asynchronous cooperative triggered discharge of the multiple HTSPPS with ICCOS modules in parallel, the appropriate amplitude and flat shape current of the load can be achieved through the careful design of the trigger time.

In the rail-type electromagnetic launching system, the equivalent load of pulsed-power supplies (PSs) varies with the launching process, while it has a certain influence on the discharge of pulsed PS. However, in the analysis and design of pulsed PS, researchers usually use the fixed resistance and inductance to simulate the load, which is impossible to accurately study the characteristics of the pulsed PS. The electromagnetic launching needs high-amplitude current pulse. Therefore, in this paper, a mathematical model of electromagnetic launching system driven by multiple superconducting inductive pulsed PS modules is established. In this model, the fixed resistance and inductance load are replaced by the dynamic load model of the railgun; the effects of dynamic load and fixed load on the discharge characteristics are analyzed; the parallel discharge characteristics of multiple high-temperature superconducting pulsed-power transformer (HTSPPT) modules are studied; and the characteristics of the simple rail-type electromagnetic launching driven by multiple HTSPPT modules are analyzed. The simulation results show that a high amplitude of current pulse can be produced using synchronous parallel discharge of multiple HTSPPT modules. The simulation results show that when the resistance and inductance of load are fixed at 2 $\text{m}\Omega$ and 0.5 $\mu \text{H}$ , respectively, the current amplification factor is 15.666, and the maximum voltage of the auxiliary capacitor is 1079 V. In the dynamic load model, the current amplification factor is 17.174, and the error is 9.6%. The maximum voltage of the auxiliary capacitor is 983 V, and the error is 8.9%. Therefore, the discharge characteristics of pulsed PS can be more accurately studied using dynamic models.

The opening switch is one of the critical technologies in the development of inductive pulsed-power supply. The power requirement is very high when the opening switch is desired to commutate a large current. This paper presents a zero-current opening circuit for inductive pulsed-power supply based on a high-temperature superconducting pulsed-power transformer. First, there are two types of current flowing through the opening switch, one comes from the secondary side of the pulse transformer, and the other one comes from superconducting energy storage inductance. The orientation of the two current is opposite. Then, when the current flowing through the opening switch closes to zero, the switch is opened and this restrains the over-voltage pulse of the opening switch. The simulation results indicate that this zero-current opening circuit is feasible and has potential applications for high-energy systems in the future electromagnetic launcher.

针对配电网线路主体多为含分支的“架空线—电缆”混合线路这一异于输电线路的特征,建立配电网常见的“架空线—电缆—架空线”三段式混合线路模型,每段设置分支.在此基础上,提出了一套针对该线路的故障定位方法,利用比较特殊点故障时和一般点故障时每段线路各分支末端行波到达时刻与线缆连接点行波到达时刻差值的方法,确定故障发生在三段中哪一段.再进一步选择两两分支线路末端行波时差比较,确定故障发生于具体哪一分支线路,最后提出使用综合行波测距方法,确定在分支线路中具体故障位置.PSCAD仿真结果表明,该套定位方法能较为准确地选出故障区段,并确定故障位置,且不受故障类型和过渡电阻的影响,可靠性和准确性较高.

直流母线电压稳定是直流微电网运行控制的目标之一,但由于直流微电网特殊的物理架构,易出现母线电压振荡现象.依据IEEE对电压振荡参数的规定,建立直流母线电压振荡信号的数学模型.考虑希尔伯特黄变换的模态混叠弊端,采用一种基于掩膜信号的改进希尔伯特-黄变换对母线电压振荡仿真信号进行检测.检测结果显示,该方法可以快速判断直流母线电压振荡的发生和结束时间,相对误差在0.378%以下,表明通过准确提取电压振荡信号的时频信息,希尔伯特-黄变换可实现对直流微电网母线振荡的检测与分析.