電力系統(tǒng)時滯小擾動穩(wěn)定性研究
發(fā)布時間：2019-04-02 04:52
【摘要】：隨著我國電網規(guī)模的不斷擴大和互聯程度的不斷提高,電網運行的安全性與穩(wěn)定性面臨越來越大的挑戰(zhàn),相關問題受到電力工業(yè)界和學術界的高度關注。為提高電力系統(tǒng)運行的安全穩(wěn)定性水平,利用廣域量測系統(tǒng)(WAMS)對其進行協(xié)調控制成為一種未來可能的選擇,但廣域量測系統(tǒng)信息在傳輸中存在著明顯的時滯,會對電力系統(tǒng)的穩(wěn)定運行和相關控制器的設計產生負面影響,需要加以科學考慮。為此,本文將針對含有時滯環(huán)節(jié)的電力系統(tǒng)小擾動穩(wěn)定性開展研究,主要工作如下:(1)在詳細推導電力系統(tǒng)關鍵環(huán)節(jié)和設備數學模型基礎上,利用線性化技術得到了進行時滯電力系統(tǒng)小擾動穩(wěn)定分析所需的定常模型用于后續(xù)研究,包括:典型二階時滯系統(tǒng)模型、單機-無窮大系統(tǒng)模型、WSCC-3機9節(jié)點系統(tǒng)模型和IEEE-10機39節(jié)點系統(tǒng)模型。(2)提出了一種求解電力系統(tǒng)大范圍時滯小擾動穩(wěn)定域的有效方法:首先利用參數變換技術,將大范圍時滯小擾動穩(wěn)定域邊界的求解,轉換為對有限參數空間的搜索、平移和反平移過程,大大減少了穩(wěn)定域邊界的求解量;進一步,利用四點插值法,通過對穩(wěn)定域邊界上臨界點實施微擾來確定小擾動穩(wěn)定域的邊界性質和構成;最后,利用典型二階時滯系統(tǒng)和WSCC-3機9節(jié)點時滯系統(tǒng)驗證了所給方法的有效性。(3)提出了一種適用于單時滯電力系統(tǒng)模型的簡化方法并推導了適用的線性矩陣不等式(LMI)新判據:首先將包含時滯環(huán)節(jié)的電力系統(tǒng)線性模型,擴展為包含輸入-輸出環(huán)節(jié)的狀態(tài)空間表達式;進一步,利用基于狀態(tài)空間表達式的降維方法,對擴展后的模型進行簡化,在保留系統(tǒng)關鍵動態(tài)基礎上盡量減少待求變量數;最后,基于簡化模型,推導了新的更為高效的時滯穩(wěn)定LMI判據。將該方法應用于含時滯環(huán)節(jié)的WSCC-3機9節(jié)點系統(tǒng)和IEEE-10機39節(jié)點系統(tǒng),借助二分搜索算法對比了兩種電力系統(tǒng)單時滯穩(wěn)定裕度的求解結果,算例表明時滯系統(tǒng)經過模型簡化后,在保證計算精度的前提下,計算效率大大提升。(4)提出了一種適用于多時滯系統(tǒng)且具有更高求解效率的時滯穩(wěn)定LMI新判據:首先,通過構造新的Lyapunov-Krasovskii泛函,并通過變分學方法直接得到該泛函導數取極大值的條件,從而形成新的LMI判據,在此過程中避免引入任何自由權矩陣,有效減少了判據的待求變量數;進一步,從理論上證明了新判據的極值條件與已有自由權矩陣判據的最優(yōu)值等價;最后,利用典型二階時滯系統(tǒng)、單機-無窮大系統(tǒng)和WSCC-3機9節(jié)點系統(tǒng),驗證了所提方法的有效性,計算結果表明新判據在求解相同時滯穩(wěn)定裕度的情況下,計算效率得到大大提升。
[Abstract]:With the continuous expansion of power grid scale and the continuous improvement of interconnection degree, the security and stability of power grid operation are facing more and more challenges, and the related problems have been highly concerned by the power industry and academia. In order to improve the security and stability of power system operation, the coordinated control of wide area measurement system (WAMS) is a possible choice in the future, but there is obvious time delay in the transmission of wide area measurement system information. It will have a negative effect on the stable operation of the power system and the design of the related controllers, which need to be considered scientifically. The main work of this paper is as follows: (1) on the basis of deducing the key link and equipment mathematical model of power system in detail, the stability of power system with time-delay is studied in this paper. By means of linearization technique, the steady state model needed for small disturbance stability analysis of time-delay power system is obtained for further study, including: typical second-order time-delay system model, single-machine-infinite bus system model, and so on. WSCC- 3 machine 9-bus system model and IEEE- 10 machine 39-bus system model. (2) an effective method to solve the stability region of large-scale time-delay and small disturbance in power system is proposed. Firstly, the parameter transformation technique is used to solve the stability region of power system with time-delay and small disturbance. The solution of the boundary of the stability region with large time-delay and small disturbance is transformed into the search, translation and inverse translation of the finite parameter space, which greatly reduces the solution of the boundary of the stability region. Furthermore, by using the four-point interpolation method, the boundary properties and composition of the small perturbation stability region are determined by perturbing the critical points on the boundary of the stability region. Last, The effectiveness of the proposed method is verified by using the typical second-order time-delay system and the WSCC- 3 machine 9-node time-delay system. (3) A simplified method for single time-delay power system model is proposed and the applicable linear matrix is derived. The new criterion of inequality (LMI): first of all, the linear model of power system with time-delay links is proposed. Extend to include input-output link state space expression; Furthermore, the extended model is simplified by using the dimensionality reduction method based on the state space expression, and the number of variables to be solved is reduced as much as possible on the basis of retaining the key dynamics of the system. Finally, based on the simplified model, a new and more efficient delay-stable LMI criterion is derived. The method is applied to WSCC- 3-machine 9-bus system with time-delay and 39-bus system with IEEE- 10 machine. The results of single-delay stability margin of two power systems are compared by using binary search algorithm. Numerical examples show that after simplification of the model, the computational efficiency of the time-delay system is greatly improved under the premise of ensuring the computational accuracy. (4) A new LMI criterion for time-delay stability is proposed, which is suitable for multi-time-delay systems and has higher solving efficiency: first of all, a new time-delay stability criterion is proposed for multi-time-delay systems. By constructing a new Lyapunov-Krasovskii functional and directly obtaining the condition that the derivative of the function is maximized by variational method, a new LMI criterion is formed, in which any free right matrix is avoided. It effectively reduces the number of variables to be found in the criterion. Furthermore, it is proved theoretically that the extremum condition of the new criterion is equivalent to the optimal value of the existing free-right matrix criterion. Finally, a typical second-order time-delay system, a single-machine-infinite bus system and a WSCC- 3 machine 9-bus system are used to verify the effectiveness of the proposed method. The calculation results show that the new criterion can solve the same time-delay stability margin with the same time-delay. The computational efficiency has been greatly improved.
【學位授予單位】：天津大學
【學位級別】：博士
【學位授予年份】：2014
【分類號】：TM712
，
本文編號：2452260
[Abstract]:With the continuous expansion of power grid scale and the continuous improvement of interconnection degree, the security and stability of power grid operation are facing more and more challenges, and the related problems have been highly concerned by the power industry and academia. In order to improve the security and stability of power system operation, the coordinated control of wide area measurement system (WAMS) is a possible choice in the future, but there is obvious time delay in the transmission of wide area measurement system information. It will have a negative effect on the stable operation of the power system and the design of the related controllers, which need to be considered scientifically. The main work of this paper is as follows: (1) on the basis of deducing the key link and equipment mathematical model of power system in detail, the stability of power system with time-delay is studied in this paper. By means of linearization technique, the steady state model needed for small disturbance stability analysis of time-delay power system is obtained for further study, including: typical second-order time-delay system model, single-machine-infinite bus system model, and so on. WSCC- 3 machine 9-bus system model and IEEE- 10 machine 39-bus system model. (2) an effective method to solve the stability region of large-scale time-delay and small disturbance in power system is proposed. Firstly, the parameter transformation technique is used to solve the stability region of power system with time-delay and small disturbance. The solution of the boundary of the stability region with large time-delay and small disturbance is transformed into the search, translation and inverse translation of the finite parameter space, which greatly reduces the solution of the boundary of the stability region. Furthermore, by using the four-point interpolation method, the boundary properties and composition of the small perturbation stability region are determined by perturbing the critical points on the boundary of the stability region. Last, The effectiveness of the proposed method is verified by using the typical second-order time-delay system and the WSCC- 3 machine 9-node time-delay system. (3) A simplified method for single time-delay power system model is proposed and the applicable linear matrix is derived. The new criterion of inequality (LMI): first of all, the linear model of power system with time-delay links is proposed. Extend to include input-output link state space expression; Furthermore, the extended model is simplified by using the dimensionality reduction method based on the state space expression, and the number of variables to be solved is reduced as much as possible on the basis of retaining the key dynamics of the system. Finally, based on the simplified model, a new and more efficient delay-stable LMI criterion is derived. The method is applied to WSCC- 3-machine 9-bus system with time-delay and 39-bus system with IEEE- 10 machine. The results of single-delay stability margin of two power systems are compared by using binary search algorithm. Numerical examples show that after simplification of the model, the computational efficiency of the time-delay system is greatly improved under the premise of ensuring the computational accuracy. (4) A new LMI criterion for time-delay stability is proposed, which is suitable for multi-time-delay systems and has higher solving efficiency: first of all, a new time-delay stability criterion is proposed for multi-time-delay systems. By constructing a new Lyapunov-Krasovskii functional and directly obtaining the condition that the derivative of the function is maximized by variational method, a new LMI criterion is formed, in which any free right matrix is avoided. It effectively reduces the number of variables to be found in the criterion. Furthermore, it is proved theoretically that the extremum condition of the new criterion is equivalent to the optimal value of the existing free-right matrix criterion. Finally, a typical second-order time-delay system, a single-machine-infinite bus system and a WSCC- 3 machine 9-bus system are used to verify the effectiveness of the proposed method. The calculation results show that the new criterion can solve the same time-delay stability margin with the same time-delay. The computational efficiency has been greatly improved.
【學位授予單位】：天津大學
【學位級別】：博士
【學位授予年份】：2014
【分類號】：TM712
，
本文編號：2452260
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