Inverter Control Observer for Delay Compensation
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Solution Overview
Problem
Existing methods for controlling converters with controllable power semiconductors fail to account for delay effects, leading to instability and the need for slower control, which limits the converter's performance.
Innovation Solution
A method that includes a monitoring unit providing delayed state model readings, allowing for the calculation of model deviation differences, which are then used to model the converter with an observation unit, effectively compensating for delay effects and improving control stability by minimizing model deviation differences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If delay effects are not taken into account in converter control, then the control can be implemented with simpler methods, but the stability of the control deteriorates and the control speed must be reduced
Solution Approach 1:
The observer calculates estimated state variables in advance based on the delayed measurement values and system model, effectively predicting the current state before the control action is applied. This preliminary estimation compensates for the delay effects without requiring complex real-time calculations during the control cycle.
Solution Approach 2:
The observer acts as an intermediary between the delayed measurement values and the control unit, processing the delayed information through mathematical models to generate accurate state estimates that the control unit can use as if they were real-time values.
2Reliability
If the control is made significantly slower to guarantee stability, then control stability is improved, but the productivity and response speed of the converter deteriorates
Solution Approach 1:
By calculating the state estimates in advance using the observer, the system prepares accurate state information before the control decision is made, enabling fast control cycles without sacrificing stability. The observer runs independently and provides ready-to-use estimates for the control unit.
Solution Approach 2:
The observer continuously updates the state estimates based on the difference between actual delayed measurements and model predictions, creating a feedback mechanism that maintains accuracy despite delays. This allows high-speed control with stable performance.
3Productivity
If the control is made faster to improve productivity, then the response speed is improved, but control stability deteriorates due to delay effects
Solution Approach 1:
The observer computes accurate state estimates in advance using system models and delayed measurements, providing the control unit with information that reflects the current system state rather than delayed state. This enables fast control响应 while maintaining stability.
Solution Approach 2:
The observer serves as an intermediary that transforms delayed measurement data into accurate real-time state estimates, allowing the control system to operate at high speeds without being constrained by measurement and actuation delays.
Data Source
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AI summary
In order to provide a method for controlling an inverter (1) comprising controllable power semiconductors, wherein actual state values x^(k) describing the state of the inverter (1) are compared to target state values x Soll(k) to obtain control difference values, the control difference values are fed to a control unit (14, 16) which generates actuating voltage values u(k) at the output, and a control electronics unit (19) supplies control signals depending on the actuating voltage values u(k) and transmits them to the power semiconductors (S1, S2) of the inverter (1), wherein the control unit (14, 16) generates such actuating voltage values u(k) that the control difference values are as small as possible, taking delay effects into consideration, it is proposed that the actual state values x^(k) are calculated by an observation unit (21) based on the actuating voltage values u(k), wherein the observation unit (21) models the inverter (1) and takes delay effects into consideration, so that the actual state values x^(k) of delay effects correspond to released non-delayed current measurement values.