考虑暂态稳定约束的联络线最大传输功率计算

Calculation on the Maximum Transfer Capability Considering Transient Stability Constraints of Tie-lines

由于确定电力系统联络线最大功率时要考虑其故障时对系统暂态稳定的影响,故提出了一种基于能量函数灵敏度的考虑暂态稳定约束的联络线最大传输功率计算方法。该法首先确定网络在临界或失稳情况下的能量裕度及能量裕度对各发电机有功出力的灵敏度,再用等步长法和二分法按各发电机能量裕度灵敏度的大小调整有功出力,结合时域仿真法的判稳校验求出考虑暂态稳定约束的联络线极限传输功率。该法计算简单、快速,较好的解决了考虑暂态稳定约束后计算负担过重和直接法偏于保守的问题。2个算例仿真测试证实了该法的有效性。

The methods based on direct current power flow, alternate current power flow or continuous power flow were used to calculate the available transfer capability, but all the methods had not considered the transient stability constraints. On the basis of the traditional methods of calculating the available transfer capability, this paper presents a method of calculating the maximum transfer capability of the tie lines. Considering tie lines＂ transient stability constraints, the method is based on corrected transient energy function sensitivity. The classical model of the transient stability calculation is used in this method. Firstly, the energy margin and energy margin sensitivity of each generator＇s active power outputs are fixed on the critical or the unstable environment of the network. ; then the active power outputs of generators are adjusted by the methods of the equal step and the dichotomy, according to the sensitivity of each generator＇s active power outputs; finally, the maximum transfer capability of the tie lines which considers the transient stability constraints, is calculated based on the checkout of the stability which is the result of a time domain simulation analysis. The proposed process of the calculation is very simple and fast, it avoids the problem of hard calculation amount to be carried out in an effective way after the transient stability constraints are considered, and it overcomes the conservative results when using the direct method. At last, using the simulation procedure, the effectiveness of the proposed algorithm is verified by the calculation results of a 30-bus system and a 60-bus system, which are improved from the IEEE 30 bus system.