When the V2G available capacity in next week.

When the electric vehicles participate in regionaldistribution network for peak power regulation, it must bearranged in corresponding region scheduling scheme. TheV2G forecasting is necessary, which include prediction of thenumber of vehicle participated in V2G service, the totalavailable capacity, the available power in each time. Accurateforecast the parameters of V2G is the basic elements of realizethe functions of V2G. It is because of V2G power withtwo-way interaction and the user interaction, so the predictionof V2G available capacity is more complex than the traditionalload forecasting. From technology to analyze, V2G storagecapacity can be acquired through the following two ways.egin{enumerate} item { extit{ EVs user settings}}:  It means that the vehicle owners set next week program of participate V2G vehicle in the weekend, then the V2G station control system can count the V2G available capacity in next week. In the actual implementation of charging and discharging priority use the plan capacity. The model is similar to the contract market and real-time market in power market and has good promotion prospects. item { extit{ V2G capacity}}: V2G capacity is closely related with the amount of participated vehicle, user’s hobbit, weather, energy price, season and the economic development. In the initial of V2G service, relatively few vehicles involved, so can adopt the method that discharge all the vehicle at the peak power time and charge in low power time. As technology and markets mature, the number of vehicle participate the V2G will increase, and the historical data will gradually accumulate. Then these predict methods can be applied in V2G capacity forecast, such as the time series method, exponential smoothing method, gray model method, Kalman filtering method, and some artificial intelligence methods such as expert systems, artificial neural networks, fuzzy prediction method etc. end{enumerate}subsection {Smart Charging Coordination}The interaction between EV and charging station is well-defined in international electro technical commission IEC 61851.  The IEC 61851 standard will facilitate the communication from the charging station to the EV.  Due to the incomplete the EV communication protocols standard, it is hardly applied in the current available vehicles and charging stations. Currently, the smart charge stations that are working with AC, can provide very inadequate communication. For instance, increased the number of electric vehicles and charging stations are anticipated to be increase continually. Therefore, V2G features such as data scheduling will become very important to achieve stable power grid. The communication standard implemented by the utility, normally is power line communication (PLC) that will facilitate a possible technical solution for vehicle-to-grid communication.The control signal can facilitate a two-way communication and is produced by the EV supply equipment (EVSE). The available current of the charging station will be based on the average voltage can be measured by getting the variable duty cycle and high voltage. Pulse width modulation (PWM) signals are used for a wide variety of control signal with a frequency of 1 kHz. The smart vehicle charger should not exceed the maximum of charge current. The EV has the ability to change the voltage level of the controller to signalize the vehicles charging statues. Apart from above-mentioned EV charging planning phase, the charging station is also responsible for checking the status of smart grid frequently. It has to make a proper decision when the power grid condition is not stable. For example, if the EV charging station started to schedule the charge for EV, during the charging process if the grid operation system condition changed and not stable. Hence, the EV charger station will take into their account the status of the power system and start to decreases the rat of charging gradually till the power grid status back to normal. If the power grid condition is continuous in dangers the charging station will stop charging completely.