Switched Reluctance Rotor Position Estimation Across Variable Speeds

The patent applies dynamics by making the pulse injection strategy adaptive to motor speed. The controller dynamically selects different pulse injection methods based on the current speed range: high-frequency pulse injection for low speeds, variable pulse number injection for medium speeds, and single-pulse injection for high speeds. This dynamic adaptation resolves the contradiction by optimizing position estimation accuracy for each speed condition while maintaining implementation feasibility through a unified control framework.

The patent changes the parameter of pulse number injected according to speed. At low speeds, multiple high-frequency pulses are injected; at medium speeds, the pulse number is adjusted based on a preset curve or table; at high speeds, only one pulse is injected. This parameter change strategy directly addresses the contradiction by adapting the injection parameters to match the motor's operational conditions, thereby maintaining accuracy across the full speed range.

The patent segments the speed range into three distinct sections (low-speed, medium-speed, and high-speed) and applies different pulse injection strategies to each segment. This segmentation allows the system to use multiple pulses only when necessary (low and medium speeds) while using a single pulse at high speeds, thereby maintaining accuracy where needed without unnecessarily increasing system complexity across all operating conditions.

The patent applies partial action by injecting multiple high-frequency pulses only during low-speed operation where they are most beneficial for accurate position estimation. At high speeds, where the motor's back-EMF is higher and current response is faster, a single pulse suffices. This partial application of multi-pulse injection resolves the contradiction by concentrating computational resources where they provide the most value.

The patent implements a dynamic pulse injection strategy that adapts to motor speed. At low speeds, high-frequency multiple pulses are injected to achieve fine position resolution. As speed increases to the medium range, the pulse number is adjusted according to a preset curve or table. At high speeds, a single pulse is injected. This dynamic adaptation resolves the contradiction by matching the injection strategy to the motor's capabilities at each speed level.

The patent changes the injection parameters (pulse number and frequency) according to motor speed. The controller monitors motor speed and automatically adjusts the pulse injection parameters: using high-frequency multiple pulses at low speeds for fine resolution, transitioning to variable pulse numbers at medium speeds, and using single pulses at high speeds. This parameter change approach directly resolves the speed-resolution contradiction.

The patent introduces capacitor voltage detection as an intermediary method to capture the current response at high speeds. Instead of directly measuring the difficult-to-capture single-pulse current response, the system uses a capacitor to integrate the current signal and measures the voltage across the capacitor, which provides a more easily detectable signal that still accurately reflects the rotor position. This intermediary approach resolves the contradiction between using simple single-pulse injection and maintaining position accuracy.

The patent substitutes direct current measurement with capacitor voltage measurement. The capacitor acts as an integrator that converts the difficult-to-measure current pulse into an easily measurable voltage signal. This substitution allows the system to use simple single-pulse injection at high speeds while still achieving accurate position estimation through the intermediary voltage measurement, thereby resolving the contradiction between simplicity and accuracy.