Motor Control Delay Compensation via Sampling Signal Adjustment
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Solution Overview
Problem
High pole count electric motors experience significant hardware delays that affect control performance and reduce pulse ratios, leading to instability and sensitivity issues at high motor speeds.
Innovation Solution
A method and system for controlling electric motors that compensates for hardware delays by adjusting sampling signals and scheduling current sampling to align with voltage signals, using a controller and inverter with an analog-to-digital converter to produce a voltage signal and adjust for delays introduced by hardware components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the pole count of the electric motor is increased to achieve higher fundamental frequency, then the fundamental frequency is improved, but hardware delays become significant and control performance deteriorates
Solution Approach 1:
The patent applies preliminary action by calculating and compensating for hardware delays in advance before they affect control performance. The controller pre-determines the magnitude of delays introduced by hardware components and adjusts control signals accordingly, allowing the system to maintain stable operation at high fundamental frequencies despite inherent hardware limitations
Solution Approach 2:
The patent changes parameters by dynamically adjusting control signals based on calculated delay compensation. The controller modifies timing parameters and signal characteristics to account for hardware delays, enabling the system to operate reliably at higher pole counts and fundamental frequencies where delays would normally cause instability
2Speed
If the pole count is increased for higher fundamental frequency, then the fundamental frequency is improved, but the pulse ratio is reduced and sensitivity to delays increases
Solution Approach 1:
The system performs preliminary calculation of delay magnitudes introduced by hardware components before control signals are processed. By knowing the exact delay amounts in advance, the controller can pre-compensate for them, reducing the sensitivity to delays that normally increases with lower pulse ratios
Solution Approach 2:
The patent implements feedback by continuously monitoring control performance and adjusting delay compensation accordingly. The system measures the actual effects of hardware delays and modifies compensation parameters to maintain optimal control accuracy, thereby reducing sensitivity to delays even at low pulse ratios
3Speed
If hardware delays are present in high pole count motors, then fundamental frequency is improved, but control stability deteriorates at high motor speeds
Solution Approach 1:
The controller calculates the magnitude of hardware delays in advance and applies compensation before control signals are executed. This preliminary compensation ensures that control remains stable at high motor speeds by preventing delay-induced instability from occurring in the first place
Solution Approach 2:
The system applies preliminary anti-action by introducing compensating signals that counteract the destabilizing effects of hardware delays before they can affect control stability. The controller pre-generates corrected control signals that offset the anticipated delay effects, maintaining stability during high-speed operation
Data Source
AI summary
Methods and systems are provided for controlling an electric machine via an inverter while compensating for one or more hardware delays. The method includes receiving a control signal, producing a first sampling signal based on the control signal, and adjusting the sampling signal to compensate for a first delay of the one or more hardware delays. The inverter is operable to produce a voltage signal based on the control signal, and the electric machine is operable to produce a current based on the voltage signal. A sampling of the current is performed based on the first sampling signal.