In our region we have many major power outages after storms go through the area. The last major storm affected over 700,000 people. Traffic signals in high traffic areas were not working for days. This required having safety and service personnel to erect temporary 4 way stop signs and other means to direct traffic.
This design allows the traffic signals to operate when the utility power is lost. Automatic notification is sent through the internet to the responsible traffic control authorities of the location of the outage as the backup power system takes over powering the lights. This system reduces traffic problems and the need to immediately send personnel to the location so that the manpower can be used at other higher priority situations such as marking off or guarding downed live electrical power lines.
System set up to work like this: At the main traffic control box an automatic power transfer switch is installed. When the system senses the loss of utility power after a set time it will switch to the battery backup. The set time is made to prevent any short power loss spikes from causing the switching between power systems. This ensures that the backup system is activated only when the utility power is lost for a minute or two.
The backup battery is to have sufficient amp-hour capacity to keep the specific traffic signals operating for up to 5 days. The battery is to be trickle charged during standby operation. A power inverter will convert the DC battery power to A/C power.
A system test for readiness is to be part of the operating system. The automatic testing to be conducted to occur at least weekly. It can be changed per the customer. A message of system status will be sent to the responsible authority.
LED lights in the traffic signals will reduce the power demand required from the utilities and the battery.
An optional solar panel system can be part of the backup package to extend battery operation during a power outage.