Studies on DC System Interconnection by Means of Superconducting Magnetic Energy Storage

1.利用超导线圈实现直流系统互联的实验研究将两台三相可控硅AC-DC变换器组合在一起，并利用超导线圈（L = 95 H，<max>I_2 = 20 A，储能容量= 1. 5 V）构建了一个直流输电实验系统。kj），其连接两个配电盘。采用微机控制的方法进行了吸放功率实验。功率的规定值为i）恒定功率，ii）用恒定功率切换吸收和释放，以及iii）正弦吸收和释放。实验结果表明，两个直流互联子系统可以独立控制功率。然而，完成测量值的输入、控制值的计算和输出的一个周期需要大约0.3秒，这使得功率吸收和释放的开关频率限制在大约0.6Hz。这是未来需要改进的问题 ...更多信息 控制策略和计算机控制程序.直流系统与超导线圈互联对系统稳态稳定性的改善利用特征值分析方法，对一个典型纵向电力系统的稳态稳定性进行了研究。分析结果表明，直流系统互联可显著提高系统的稳态稳定性，而超导线圈的储能能力在适当控制两个变流器的情况下可进一步稳定系统。当在互连线上存在功率流时，功率流出的系统（整流器侧）显著稳定。提高暂态稳定性通过计算机仿真，对上述相同的电力系统进行了功率振荡阻尼效果的研究。假设干扰是发电机跳闸。将系统按直流互联划分，一个子系统上的扰动几乎诺托影响另一个子系统。超导线圈的引入可以使功率摆动阻尼更快。少

1. Experimental Studies on DC System Interconnection Using Superconducting Coil ; Two sets of 3-phase thyristor AC-DC converter were composed, and a experimental DC transmission system was constructed with the superconducting coil ( L = 95 H, I_<max> = 20 A, Energy Storage Capacity = 1. kj ), which connects two distribution boards. Experiments of power absorption and release were done by means of personal computer control. The specified values of power were i) constant power, ii) switching of absorption and release with constant power, and iii) sinusoidal absorption and release. It was confirmed from the experiments that the power can be controlled from the two DC interconnected subsystems independently. It takes, however, as long as about 0.3 sec to complete one cycle of the input of measured values, the computation and the output of the control value, which puts the limit of about 0.6 Hz on the switching frequency of power absorption and rellease. It is the future problems to improve … More the control strategy and the computer programming for control.2. Improvement of Steady-State Stability by DC System Interconnection with Superconducting Coil ; The system stabilizing effect of DC system interconnection and superconducting coil was examined regarding the steady-state stability on a sample longitudinal power system by means of the eigenvalue analysis. It was made clear from the results of the analysis that DC system interconnection fairly improves the steady-state stability, and that the energy storage capability of superconducting coil can stabilize the system further if the both converters are controlled appropriately. When there is a power flow on the interconnection line, the system from which the power flows out ( rectifier side ) is remarkably stabilized.3. Improvement of Transient Stability ; The power swing damping effect was examined on the same sample power system as above by means of computer simulation. The disturbance assumed was a tripping of a generator. By dividing the system by DC interconnection, the disturbance on one subsystem does noto almost affect the other subsystem. The introduction of a superconducting coil can makes the power swing damping faster. Less