Smart grid and Electric Vehicles (EVs) network is an example of the typical distributed network with heterogeneous systems. It has very strong requirement of robust and secure method of communication. Deployment of such efficient and secure communication scheme in this network is a very challenging task. From time to time EVs need to coordinate with smart grid and other entities specially, aggregators in network for charging/discharging purposes. For the security and integrity of this communication, a reliable and efficient authentication scheme is essential. Main problems for such networks are the application of security schemes in such complex distributed system when the number of EVs is very high and the load management of aggregators in the system. These issues are complicated because as the number of EVs becomes high, then the authentication delays increases and so as the load on aggregator for charging. These issues should be addressed in an efficient way otherwise the delay for authentication becomes intolerable for customers. Communication traffic and computational delay also increases in case of peak traffic time. If a certain method for authenticating large number of EVs is devised, the load for charging huge number of authenticated EVs in short time is difficult. Therefore, in order to reduce these service degrading factors, we have proposed a hybrid authentication and load management scheme for aggregators to deal with any number of EVs and load based on a distributed power control network. The proposed authentication scheme consists of the use of digital signature algorithm and batch authentication scheme. The hybrid algorithm based on these schemes makes the aggregators in the network to work in different modes based on amount of traffic in the network which results in lesser authentication delay and communication traffic as compared to when these two authentication schemes were used separately. Also we devised a novel scheme which deals with excessive load conditions in aggregators and distributes the load in an excellent manner among all aggregators in the network. In this way we achieve a novel and better strategy for uniformly distributed charging load on aggregator, secure and efficient authentication and communication in distributed power control network.