Electric wire protection device

• Main Authors: Ueta, Keisuke, Ezoe, Rikuya, Nishino, Tomoya, Tsukioka, Masataka, Kikuchi, Takashi, Nagakura, Syunsuke, Miyakawa, Takahiro, Kawamata, Seiju, Ujigawa, Noboru
• Format: Patent
• Language: English
• Published: 07.07.2020
• Subjects: BASIC ELECTRIC ELEMENTS; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRIC SWITCHES; ELECTRICITY; EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS; EMERGENCY PROTECTIVE DEVICES; GENERATION; MEASURING; MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES; MEASURING QUANTITY OF HEAT; MEASURING TEMPERATURE; PHYSICS; RELAYS; SELECTORS; TESTING; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR

An electric wire protection device includes a voltage adjuster that adjusts voltage on a power source side to be supplied to a load and a controller that includes a temperature calculation part which calculates temperature information of an electric wire based on a current value flowing through the voltage adjuster. The controller sets a first time constant as a time constant used to calculate the temperature information while the voltage adjuster is in the interrupted state, and sets a second time constant as a time constant used to calculate the temperature information while the voltage adjuster supplies power to the load. The first time constant is a value larger than the second time constant and equal to or larger than an actual time constant of the electric wire, and the second time constant is a value smaller than the actual time constant of the electric wire.