With the widespread random access of distributed resources in the new power system, precise measurement of bus current under complex operating conditions has brought new challenges. Tunnel magnetoresistance (TMR) sensors, as the latest generation of magnetoresistance sensors, integrate the advantages of high sensitivity, low power consumption, and small size of traditional magnetic sensors. They have a wide range of applications in magnetic fields detection, current detection, magnetic memory and other fields. Due to the skin effect of bus current at high frequencies, the current is concentrated in the “skin” part of the conductor, and the surrounding magnetic field exhibits nonlinear characteristics that affect the measurement of the sensor. An optimization method for arranging the position and quantity of tunnel magnetoresistance chips around the distribution bus is proposed, based on the physical characteristics of tunnel reluctance sensors and the disturbance law of skin effect. The corresponding sensor structure is designed to reduce the influence of bus skin effect and stray magnetic field on sensor measurement accuracy.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |