Conversion state estimation method of equivalent voltage measurement taking PMU into account

Abstract

The invention provides a conversion state estimation method of equivalent voltage measurement taking PMU into account. Aiming at the characteristics of measurement data of a supervision control and data acquisition (SCADA) system and a wide-area measurement system (WAMS), the invention provides the conversion state estimation of equivalent voltage measurement taking a phasor measurement unit (PMU) into account. By utilizing a measurement conversion method, the invention converses various measurements under the SCADA system and the WAMS into equivalent voltage measurement and obtains an information matrix of constant real numbers by simplification treatment, thus realizing the decoupling calculation of a real component and an imaginary component of nodal voltage. The estimation method is characterized by fast calculation speed and overcomes the defect that the traditional conversion state estimate of measurement only can treat power measurement of a single circuit branch. An IEEE-30 node system verifies the effectiveness of the provided method.

Description

(1) Technical field [0001] The invention relates to a power system state estimation technology, in particular to an equivalent voltage measurement transformation technology. (2) Background technology [0002] Aiming at the characteristics of measurement data of current supervisory control and data acquisition (SCADA) system and wide-area measurement system (WAMS), a phasor measurement unit (phasor measurement unit) is proposed. unit, PMU) equivalent voltage measurement transformation state estimation. In this paper, various measurements under the SCADA and WAMS systems are converted into equivalent voltage measurements by using the quantity measurement transformation method, and the constant real number information matrix is ​​obtained after simplified processing, and the decoupling calculation of the real and imaginary parts of the node voltage is realized. The algorithm has the characteristics of fast calculation speed, and overcomes the disadvantage that the traditional ...

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Problems solved by technology

[0004] Literature (Phadke A G, Thorp J S, Karimi K J. State estimation with phsor measurements[J]. IEEETrans on Power Systems, 1986, 1(1): 233-241; Lu Zhigang, Xu Shifan, Shi Zenghong, etc. Partial voltage and current vector State estimation of voltage phase angle when it can be measured [J]. Power System Automation, 2000, 24(1): 42-44) proposed a linear state estimation algorithm that completely uses PMU measurement. The solution of the system state quantity does not need iteration, and can be It can be obtained by direct calculation, but the number of PMUs meets the observable requirements of the power system and cannot be realized in a short time, and the expression of its linear state estimation is complex, and the program implementation is relatively complicated; literature (Li Dahu, Cao's family. Based on the SCADA / PMU mixed quantity Wide-area dynamic real-time state estimation method [J]. Power Grid Technology, 2007, 31 (6): 72-78) uses the sensitivity relationship of each node voltage change, through the supervision control and data acquisition (supervision control and data acquisition, SCADA ) system provides the initial value and the voltage measurement of the installed PMU node to obtain the voltage phasor of other nodes without PMU installed, which solves the situation of insufficient PMU measurement to a certain extent; literature (Li Qiang, Zhou Jingyang, Yu Erkeng, etc. based on Hybrid Algorithm for Power System State Estimation Based on Hybrid Measurements [J]. Power System Automation, 2005, 29(19): 31-35; Li Qiang, Zhou Jingyang, Yu Erkeng, et al. Linear State Estimation of Power System Based on Phasor Measurement [J]. Electric Power System Automation, 2005, 29(18): 24-28) On the basis of traditional state estimation results, use state quantity conversion prediction and power flow calculation to obtain forecast state and forecast node injection current, together with PMU measurement Carry out linear state estimation, this method improves the practicability and accuracy of state estimation; literature [8] uses the equivalent current measurement transformation method to obtain the constant Jacobian matrix and information matrix, and realizes the real part of the node voltage , imaginary part decoupling calculation, but the condition number of the information matrix is ​​large, which is not conducive to convergence; literature (Wu Dugui, Xu Zheng. Harmonic state estimation of power system based on phasor measurement (I)-theory, model and solution algorithm [J]. Chinese Journal of Electrotechnical Society, 2004, 19(2): 64-68; Wu Dugui, Xu Zheng. Harmonic State Estimation of Power System Based on Phasor Measurement (II) - Observability, Quality Evaluation and Example Study[ J]. Journal of Electrotechnical Society, 2004, 19(3): 76-81) established a linear harmonic state estimation model using PMU measurement, which opened up a new field for the application research of PMU measurement

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