Research On Identification Of Induction Motor Load Parameters And Analytical Method For Its Dynamic Performances

With the implement and deep of "power transmission from west to east and interregional wide interconnection" strategy, load center of "Yangtze River Delta" and "Pearl River Delta" in our country have all formed a typical structure of receiving-end grid. Due to the insufficient of power supply and constant power characteristics of the air conditioner induction motor load has a high proportion in the receiving-end system, the massive dynamic power absorbed during the fault period and the recovery process often leads to transient voltage stability problem. In order to precaution and control the transient voltage stability of the receiving-end system, it is very necessary to quickly and accurately calculate the model parameters and dynamic power characteristics for induction motor synthesis load.There are several methods to obtain the model parameters of induction motor, in which, estimating the model parameters of induction motor using for power system stability analysis according to the nameplate data is a significant promising approach with potential application. In order to overcome the shortage of approximate constraints added by researchers of these methods, the paper proposes a novel optimal mathematical model to identify the parameters of induction motors single cage and double cage models. The main objective of this proposed model is to minimize calculation efficiency deviation, while the constraints concluding induction motor stator current, input reactive power, maximum electromagnetic torque and starting argument as well as other important performance indices equaled to nameplate data. The sequence quadratic programming algorithm is used to solve the problem. The comparison with other methods in literature shows that the model parameters obtained by the proposed approach can reflect the working characteristics of induction motor better.In this paper, the characteristics and applicability of several popular induction motor models are studied. According to the characteristics that first-order mechanical transient model exhibits high precision on active power and the voltage transient model exhibits high precision on reactive power, innovation analytical calculations of the transient active and reactive power of induction motor with symmetrical and asymmetrical voltage sags. On this basis, the paper further implement the analysis with certain proportion of induction motor synthesis load model on transient power characteristics. Compared with the simulation results that obtained by electromagnetic transient simulation program PSCAD/EMTDC and electromechanical transient simulation program PSD-BPA, the accuracy and effectiveness of the analytical algorithm are verified.This paper provides a new method for planning and operating people in power system to obtain parameters of induction motor model. It also has some certain promotion function to load modeling. The thesis puts forward an analytical model and algorithm for induction motor load dynamic power characteristic, which overcome limitations of load transient power demand obtained by traditional simulation calculation. As a result, it has good theoretical value and application prospect.