| 摘要 |
PURPOSE: To make it possible to effectively utilize the capacitance of all resistors for operation by determining priorities in closing switching devices, calculating the number of resistors required from a calculated value of the estimated amount of regenerative power generated, and outputting closing signals to the switching devices according to the calculated number of resistors required and closing priority signals. CONSTITUTION: Direct current motors 3 operate on variable d.c. voltage, and resistors 4, connected to contactors 5, consume regeneratlve power. A closing priority determining circuit 12 determines the priorities in closing the contactors 5 according to the connection information from a resistor connection time managing circuit 11. A regeneratlve power calculating circuit 8 estimates the amount of regenerative power generated based on the value of current passing through the d.c. motors 3. A number of resistors required calculating circuit 9 calculates the number of resistors 4 required according to the result of the estimation. A resistor connection instructing circuit 10 outputs closing signals to the contactors 5 according to the calculated number of resistors required and priority signals. This makes it possible to effectively utilize the regenerative resistors 4, which enables the construction of a system smaller and more inexpensive than conventional ones. |
