Wan J.,Chongqing Ultra High Voltage Bureau |
Chen T.,Chongqing Ultra High Voltage Bureau |
Guo Z.-H.,Chongqing Ultra High Voltage Bureau |
Tuo Y.-K.,Chongqing University |
And 4 more authors.
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2010
A novel grid-connected dual frequency inverter for photovoltaic generation is proposed. The inverter consists of two cascaded standard half bridges, one of the half bridges works in high frequency to improve the performance of output current and the other one works in low frequency to handle power thereby the switching losses can be reduced and the system efficiency can be improved. For the high frequency half bridge, the one-cycle control is adopted. The simulation results illustrate that the inverter is controlled to generate the output current in phase with the grid voltage with low harmonic distortion and better dynamic performance.
Luo J.,Chongqing University |
Feng S.,Chongqing University |
Cai M.,Chongqing University |
Xia Y.,Chongqing Ultra high Voltage Bureau
Dianli Xitong Zidonghua/Automation of Electric Power Systems | Year: 2011
Because of immeasurable variables, synchronous generator parameter estimation need to solve complex differential equations, which might lead to difficulties in the parameters estimation process. This paper presents a new generator model, on which all the variables can be measured. Firstly, the model is a good guarantee of both the precision and the stationarity of the parameter estimation. Secondly, because all the variables in the model can be measured, we can avoid solving complex differential equations, so that the stability of identification process and the arithmetic speed can be improved and the parameter estimation will become simple and convenient. The identifiability of the model parameters is analyzed in detail to conclude that the model parameters are uniquely identifiable when the steady-state equations are used as an additional condition. The model parameters are estimated using least squares estimation algorithm according to steady-state data and dynamic-state data respectively. The test results with PSASP show that the model presented in this paper is correct, feasible and valid. © 2011 State Grid Electric Power Research Institute Press.