Researchers at the Indian Institute of Technology (IIT), Guwahati have developed optimized control schemes for active power distribution networks that can enable coordinated operation of photovoltaic (PV) power generation and electric vehicle (EV) charging stations.
However, solar power is intermittent, causing problems with voltage fluctuations in the power distribution network. In addition, EV charging is currently disorganized, leading to under-voltage of the distribution network and associated efficiency loss.
Dr. S Ganguli, Department of Electronics and Electrical Engineering (EEE), IIT Guwahati said, – We have developed an optimization-based integrated voltage control approach of power distribution networks to reduce overvoltage and under-voltage problems due to high PV generation.
IIT Guwahati said in a press release that the sustainability of EVs can be enhanced if the power used to charge these vehicles is also based on renewable energy sources such as solar power.
Our three-phase model helps maintain the EV battery’s bus voltage magnitude and state of charge (SOC) within safe limits with minimal use of control resources and cost of power consumption, – S Ganguli, added.
There is a need for a coordinated control approach to the power distribution system to derive maximum benefit from renewable energy generation and electric vehicle power sourcing. The institute said that PV and EV inverters need to work in coordination with other Voltage Regulating Devices (VRDs) to regulate the system voltage.
The research team has developed a three-stage model predictive control (MPC) approach to schedule the charging of electric vehicles and other equipment, the release said. The three phases include coordination of volt-var devices in two different time scales, reception of reactive power set points by the local controller, and EV charge scheduling according to a balance between operating cost and customer satisfaction.
The approach developed by the IIT-Guwahati team also provides a framework for transitioning from passive power distribution to active. Both solar power generation and EV can enable the transition of power distribution from a passive state (one-way flow of electricity from the grid to the consumer) to an active system in which there is a bidirectional flow of electricity from the grid to the point of use, and vice versa.
The approach proposed by Dr Ganguli and his team will help regulate the voltage generated by intermittent PV systems and pave the way for EVs to participate in proactive power distribution planning, the release said.
It provides a framework for optimum G2V and V2G operation of EVs while keeping the voltage of each node of the distribution network within acceptable upper and lower limits. The charging or discharging of EVs is optimally determined with respect to real time power pricing.
