| 摘要 |
PROBLEM TO BE SOLVED: To obtain a solar power system which enables to find whether the system is buying or selling power indoors. SOLUTION: A system linkage between distributed power supplies using solar cells 20 and a commercial power supply AC is composed, and a power is supplied to load through branch circuits Lb branched from main lines Lm. The instantaneous current is obtained by current transformers CT2a and CT2b on the main lines Lm between the commercial power supply AC and the branch circuits Lb. A signal conversion circuit 14 detects a state whether the system is buying or selling power, in accordance with a product of the instantaneous line voltage between the main lines Lm and the instantaneous current obtained by the current transformers CT2a and CT2b. Buying or selling detected by the signal conversion circuit 14 is transferred to a display device 5 through a linkage protective circuit 25 and displayed on the display device 5. The display device 5 is located indoors, and hence buying or selling can be recognized indoors. |
