Padmount transformer with energy storage apparatus
The present disclosure is directed to a padmount transformer. The padmount transformer includes an electrical distribution transformer housed in a cabinet that can be mounted on a ground level platform or pad. High/medium voltage connectors of the electrical distribution transformer can connect to high/medium voltage terminals of a power supply network. Low voltage connectors of the electrical distribution transformer are configured to connect to low voltage terminals of one or more loads coupled to respective renewable energy sources. The high/medium voltage connectors and the low voltage connectors are housed in the cabinet. An energy storage apparatus is housed in the cabinet and is connected with the low voltage connectors for supplying power to the loads. Power can be supplied to the energy storage apparatus by the renewable energy sources. An inverter is operable for commanding the power supply direction at the energy storage apparatus and a control unit is configured to control the inverter.
1. A padmount transformer comprising:
a cabinet;
an electrical distribution transformer housed in the cabinet to be mounted on a ground level platform or pad;
high/medium voltage connectors for connecting the electrical distribution transformer to high/medium voltage terminals of a power supply network, and low voltage connectors for connecting the electrical distribution transformer to low voltage terminals of one or more loads coupled to respective renewable energy sources, the high/medium voltage connectors and the low voltage connectors being housed in the cabinet;
an energy storage apparatus housed in the cabinet and connected with the low voltage connectors for supplying power to said one or more loads and for being power supplied by the renewable energy sources coupled thereto;
an inverter for commanding the power supply direction at the energy storage apparatus, said inverter being housed in the cabinet;
a control unit for controlling the inverter.
2. A padmount transformer according to claim 1 , wherein the control unit is configured to command the inverter such that when the power produced by the renewal energy sources exceeds the overall loads power demand, the exceeding power is stored in the energy storage apparatus.
3. A padmount transformer according to claim 1 , wherein the control unit is configured to command the inverter such that, when the power produced by the renewable energy sources is lower than the overall loads power demand, at least a portion of the power missing at the loads is supplied by the energy storage apparatus.
4. A padmount transformer according to claim 1 , comprising standard low voltage connectors for connection to standard loads of said one or more loads and higher priority low voltage connectors for connection to higher priority loads of said one or more loads, wherein the control unit is configured to command the inverter such that a predetermined safety energy reserve is maintained in the energy storage apparatus to be supplied only to the higher priority loads in case of a blackout in the power supply network when the energy reserve in the energy storage apparatus is below said safety energy reserve.
5. A padmount transformer according to claim 4 , comprising switching devices associated to the standard low voltage connectors and to the higher priority low voltage connectors.
6. A padmount transformer according to claim 1 , comprising a switching device to connect/disconnect the inverter from the low voltage network.
7. A padmount transformer according to claim 1 , wherein the energy storage apparatus comprises a battery pack, or a supercapacitor or a fuel cell.
8. A padmount transformer according to claim 1 , wherein the energy storage apparatus is connected to the electrical distribution transformer such that the energy storage apparatus can supply power to and be power supplied by the power supply network.
9. A padmount transformer according to claim 8 , wherein the distribution transformer comprises a primary winding, a first secondary windings for supplying the loads, and a second secondary winding for supplying the energy storage apparatus.
10. A padmount transformer according to claim 8 , wherein the distribution transformer comprises a third secondary winding connected to the inverter.
11. A padmount transformer according to claim 8 , wherein the control unit is configured to control the inverter such that the energy storage apparatus absorbs energy from or injects energy to the power supply network in order to keep the grid voltage in a predetermined range of values.
12. A padmount transformer according to claim 8 , wherein the control unit is configured to control the inverter such that the energy storage apparatus acts for compensating voltage sags and dips in the power distribution network.
13. A padmount transformer according to claim 8 , wherein the control unit is configured to control the inverter such that the energy storage apparatus acts as an active filter for the power distribution network.
14. A padmount transformer according to claim 8 , wherein the control unit is configured to control the inverter such that the energy storage apparatus acts for at least partially eliminating reactive power in the power distribution network.
15. A padmount transformer according to claim 8 , wherein the control unit is configured to control the inverter such that the energy storage apparatus performs a phase balancing in the power distribution network.
16. A padmount transformer according to claim 1 , comprising a switching device to connect/disconnect the inverter from the transformer.
17. A padmount transformer according to claim 1 , wherein the electrical distribution transformer is housed in a transformer compartment of the cabinet, the electrical transformer being immersed in a tank of oil.
18. A padmount transformer according to claim 17 , wherein the energy storage apparatus is housed in a separate energy storage compartment of the cabinet.
19. A padmount transformer according to claim 18 , wherein the inverter is housed in a separate inverter compartment of the cabinet.