Assessment and mitigation of voltage violations by solar panels in a residential distribution grid

Abstract

Abstract-Distributed renewable electricity generators, such as solar cells and wind turbines introduce bidirectional energy flows in the low-voltage power grid, possibly causing voltage violations and grid instabilities. The current solution to this problem comprises automatically switching off some of the local generators, resulting in a loss of green energy. In this paper we study the impact of different solar panel penetration levels in an residential area and the corresponding effects on the distribution feeder line. To mitigate these problems, we assess how effective it is to locally store excess energy in batteries. A case study on a residential feeder serving 63 houses shows that if 80% of them have photo-voltaic (PV) panels, 45% of them would be switched off, resulting in 482 kWh of PV-generated energy being lost. We show that providing a 9 kWh battery at each house can mitigate some voltage violations, and therefor allowing for more renewable energy to be used.

Exploiting V2G to optimize residential energy consumption with electrical vehicle (dis)charging

“…voltage violations, power quality etc. especially when considering also renewable energy sources (such as photo-voltaic panels installed in the homes [12]) and the opportunities of exploiting V2G to counter those power issues. Complementary work involves judging, and possibly minimizing, the impact the increased number of charging and discharging cycles has on the lifetime of the batteries.…”

LINEAR breakthrough project: Large-scale implementation of smart grid technologies in distribution grids

“…The impact of these battery storage systems on the electrical residential distribution grid was studied in [34], where a trade off between voltage regulation, power reduction and annual cost was proposed. The effectiveness of BESS to mitigate voltage violations was studied in [35]. Considering thermal energy storage, the flexibility potential of residential heat pumps combined with a storage tank is assessed in [36].…”

Modeling and Analysis of a PV Grid-Tied Smart Inverter's Support Functions

“…A combination of light loading and large generation, easily realizable for solar power when people are at work during the day and the sun is shinning its brightest, can have a significant influence on the feeder voltage [16]. In some cases the voltage rises to a level such that it becomes greater than specified limits and certain generation systems have to be disconnected from the grid, wasting potential clean renewable energy production [17]. Frequency can vary in a power system when there is an imbalance between power generation and demand [11].…”

“…Combining (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16) and (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17) yields the instantaneous DC bus power that the capacitor will need to sink or source every half cycle:…”

“…Integrating (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18) for one half cycle and setting it equal to the expression for energy stored in a capacitor, rearranging the result, the equation to size the input capacitor is expressed as:…”