This makes sense only for systems that are larger than a kilowatt of peak power and that have sufficient battery capacity. Local systems in one building could be connected to local low-voltage DC or 230V AC grids to improve the security of supply.
当涉及单相或三相230V交流电（为大型机械供电时），就必须用到变频装置。变频装置仅适用于功率峰值大于1千瓦、且电池容量充足的系统。建筑供电系统可以和当地低压直流或230V交流电网相连，以此来改善供电的安全性。