| 摘要 |
PROBLEM TO BE SOLVED: To perform temperature protection of a brake power element by calculating a switching frequency and calculating a total loss of the brake power element.SOLUTION: An internal loss of a power conversion device is preliminarily stored in a storage part. A switching frequency f and a duty ratio Ton/T of a brake power element 1 are calculated by using a voltage detection value V of a DC intermediate circuit, a regenerative electric power P1, a reverse flow power P2, and the internal loss Plossp of the power conversion device. A total loss Ploss of the brake power element 1 is calculated by using the calculated switching frequency f and duty ratio Ton/T of the brake power element 1.SELECTED DRAWING: Figure 4 |
