Inverter thermal protection
View Patent ↗An inverter has three redundant modes of thermal protection providing fire protection and secures protection of the inverter from thermal damage. An embodiment of the present invention is disclosed wherein thermal transducers or actuators are located on a control circuit board, a heat sink, and a power circuit board. Two of the modes of thermal protection are active and one is passive.
1. An inverter connected to a photovoltaic panel comprising:
a chassis with a top, a bottom, two sides, a front, and a back;
inverter circuitry attached to said chassis;
at least two temperature sensors located at two different locations within said chassis;
devices associated with each of said temperature sensors for interrupting operation of said inverter if a temperature measured by at least one of said temperature sensors exceeds a predetermined value; and
a set of electrical cables that connect said inverter circuitry to an alternating current (AC) power grid and a switch in said cables for disconnecting said inverter circuitry from said AC power grid wherein at least one of said temperature sensors and its respective device for interrupting operation of said inverter is located near said switch.
2. The inverter of claim 1 wherein at least one of said temperature sensors and its respective device for interrupting operation of said inverter is a passive sensor and device.
3. The inverter of claim 2 comprising three temperature sensors and three devices associated with said temperature sensors for interrupting operation of said inverter.
4. The inverter of claim 1 wherein at least one of said temperature sensors is located near the top of said chassis and at least one of said temperature sensors is located near the bottom of said chassis.
5. The inverter of claim 2 wherein at least one of said temperature sensors is located near the top of said chassis and at least one of said temperature sensors is located near the bottom of said chassis.
6. The inverter of claim 3 wherein at least one of said temperature sensors is located near the top of said chassis and at least one of said temperature sensors is located near the bottom of said chassis.
7. The inverter of claim 4 wherein said at least one of said temperature sensors and its respective device for interrupting operation of said inverter that is located near the bottom of said chassis is a passive sensor and device.
8. The inverter of claim 1 further comprising a heat sink located at the top of said chassis and wherein at least one of said temperature sensors is mounted on said heat sink to monitor the temperature thereof.
9. The inverter of claim 1 further comprising a control circuit board with a temperature sensor mounted on said control circuit board to monitor the temperature thereof.
10. The inverter of claim 1 further comprising a power circuit board with a temperature sensor mounted on said power circuit to monitor the temperature thereof.
11. The inverter of claim 10 wherein said power circuit board is mounted in said chassis near the bottom of said chassis.
12. The inverter of claim 10 wherein said temperature sensor mounted on said power circuit board and its respective device for interrupting operation of said inverter is a passive sensor and device.
13. The inverter of claim 12 wherein said temperature sensor mounted on said power circuit board is a bi-metal thermostat.
14. The inverter of claim 1 wherein at least one temperature sensor and its respective device for interrupting operation of said inverter located near said switch opens said switch when the measured temperature exceeds a predetermined value.
15. The inverter of claim 14 wherein said at least one temperature sensor and its respective device for interrupting operation of said inverter located near said switch is a passive sensor and device.
16. The inverter of claim 15 wherein said at least one temperature sensor located near said switch is a bi-metal thermostat.