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SSDC(Supplementary sub-synchronous oscillation damping controller) is one of effective measures to suppress the SSO(sub-synchronous oscillations) caused by HVDC. The article researched the phase compensation method of SSDC on the basis of studying the SSO and the SSDC mechanism in depth. We verified the validity of the method used by designing SSDC in an large domestic HVDC simulation model. And we find that the SSDC designed can effectively increase the positive electrical damping in the sub-synchronous frequency range with the sub-synchronous frequency scanning to suppress the SSO.

As a promising transport in the future, electric vehicles plays an important role in people's lives and energy conservation. Planning of electric vehicle charging stations has a far-reaching significance for the popularity of electric vehicles. In this paper, we discuss the siting problem of electric vehicle charging station and propose a two-step method of optimization method. Firstly, we establish a charging station location model, then use Voronoi diagram to determine the preliminary zone, finally we get this problem optimally solved by immune algorithm.The example verifies feasibility of this model.

The electric demand of EV in the public transportation sector is increasingly important to the future city’s power distribution and even infrastructure construction. According to the characteristic of public transportation, this paper analyzed the influence factors of EV power load and they were divided into three parts. Then a predicting model of EV power load in public transportation based on fuzzy clustering analysis method was put forward. We used BP (Back Propagation) neural network algorithm to solve the fuzzy clustering analysis problem. Finally the predicting model was operated in a practical example. Results showed that this predicting model of EV power load in public transportation based on fuzzy clustering analysis could be appropriately applied in reality.

This paper is based on the development process of charge-discharge experiment platform of electric cars under multi-working condition and more modules, it can carry out much charge-discharge experiment under several of control modes and parameters, and it contains lots of functions, like modular control, data collection, on-off control, human-computer interaction and environmental monitoring. There are 6 DC/DC modules in this platform, to realize these modules run independently under one backstage control system, meanwhile one module can change working condition ongoing, status inquiry and in-out operation automatic, this article proposes a new control method. It comes true by identifying critical parameters and taking into account many situations, finally we give the flow process of the method. The conclusion claim that this method could meet the request of the platform, and it has certain of reference price to such platform.

The more popular of electric vehicles is, the higher the load capacity of the battery is in the power system, therefore, the charging and discharging technology is particularly important. This paper introduces several electric vehicle battery charging methods commonly used at present, describes working principle of the bidirectional DC/DC converter in detail in the battery charging and discharging process, and the bidirectional DC/DC charging and discharging control strategy. Finally, the electric vehicle battery charging and discharging simulation model is built, the validity of the electric vehicle battery charging and discharging model is verified based on control strategies mentioned herein by use of simulation.

Electric vehicle power battery is one of the key technologies for electric vehicle charging and discharging. This paper summarized the characteristics of lithium iron phosphate battery firstly, then adopted intermittent discharge method to get the battery OCV-SOC curve under experimental tests, determined the parameters of OCV-SOC models, analyzed the advantages and disadvantages of commonly used cell performance model, finally built electric vehicle battery charging model.

In this paper, one on-board charger in the charging station will be used to test its charging process. We screen the data which has the typical characteristics of power parameters from test data, and compared with the national power quality standards. We can get the following conclusions: (1) The electric car battery is capacitive load, it may transfer the reactive power to grid in the process of charging;(2) The test data imply that frequency deviation, power factor and VTHD e.g. indexes are qualified;(3) On-board charger is mainly produced the odd harmonics in the process of charging, with the increase of harmonic frequency, harmonic contain lower rate;(4) In practice, harmonic mainly reflects on the current, voltage only has a small distortion.

In order to determine the layout of electric car charging stations, a model for optimizing charging stations location is developed after charging-demand districts are divided, the number of electric vehicles and the center of each charging district are ready. This model takes the minimization of electric vehicles charging stations total cost which includes initial fixed investment costs, operating costs and charging costs as the objective function, some related constraints which include service radius, capacity of charging station etc. are considered. Particle swarm optimization based on hybridization is proposed to solve this problem. The example verifies feasibility of this method.