Motor Braking Resistor Control for Multi-Phase Shorting Torque

The patent applies dynamics by making the stator resistance adjustable rather than fixed. The controller dynamically modifies the equivalent stator resistance based on motor speed to maintain optimal braking torque across the entire deceleration range. This is achieved through pulse-width modulation of bypass switches that selectively connect or disconnect braking resistors, transforming the static resistance into a dynamic parameter that adapts to changing operating conditions.

The patent changes the electrical resistance parameter of the stator circuit to optimize braking performance. By introducing adjustable braking resistors and using pulse-width modulation to vary the equivalent resistance, the system transforms the fixed resistance characteristic into a variable parameter. This allows the braking torque to be maintained at optimal levels throughout the speed range, resolving the contradiction between simple system design and consistent braking torque.

The patent applies universality by making the first encoder serve dual functions: it provides position feedback for motor control and simultaneously serves as a safety monitor by comparing its signals against expected values. This eliminates the need for a separate second encoder dedicated solely to safety monitoring. The single encoder performs multiple functions, reducing certification requirements while maintaining safety, thus resolving the contradiction between safety improvement and certification time/expense.

The patent applies self-service by enabling the motor control system to perform its own safety monitoring function. The controller continuously verifies the integrity of encoder signals and motor operation during normal control functions, eliminating the need for separate dedicated safety monitoring hardware. This self-monitoring capability maintains safety while reducing system complexity and certification burden.