Dead-Time Voltage Compensation in Single-Phase DC-AC Inverters
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Solution Overview
Problem
The addition of dead-time in semiconductor switching elements of single-phase DC-AC inverters leads to increased total harmonic distortion and voltage loss in the AC output, affecting the overall system performance.
Innovation Solution
A dead-time voltage compensation apparatus and method that calculates voltage losses due to dead-time and compensates the AC voltage using a processor to adjust the control reference signal, thereby reducing the impact of dead-time on the AC voltage and improving harmonic distortion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If dead-time is added to prevent short-circuiting of the DC input end, then reliability is improved, but voltage loss increases and total harmonic distortion increases
Solution Approach 1:
The patent calculates the voltage loss caused by dead-time in advance and compensates for it by adjusting the control reference signal before the actual switching occurs. This preliminary compensation action prevents the voltage loss from affecting the output quality while maintaining the necessary dead-time for reliable switching operation.
Solution Approach 2:
The patent dynamically adjusts the control reference signal parameters based on the calculated voltage loss. By changing the amplitude or timing parameters of the control signal in response to the dead-time effects, the system compensates for voltage loss and reduces harmonic distortion while maintaining the protective dead-time interval.
2Reliability
If dead-time is added to prevent short-circuiting of the DC input end, then reliability is improved, but total harmonic distortion increases
Solution Approach 1:
The system performs preliminary calculation of voltage loss and compensates the control reference signal before switching occurs, which proactively counteracts the harmonic distortion effects caused by dead-time without requiring additional hardware or complex circuit modifications.
Solution Approach 2:
The patent implements a feedback mechanism where the voltage loss caused by dead-time is calculated based on the switching state and current values, and this calculated loss is fed back to adjust the control reference signal. This closed-loop compensation effectively reduces harmonic distortion while maintaining the protective dead-time.
Data Source
AI summary
A dead-time voltage compensation apparatus and a dead-time voltage compensation method are provided. The method includes: converting a DC voltage of an input end of a single-phase DC-AC inverter into a unipolar AC voltage; calculating first to third current values based on a first inductor current value of a inductor, calculating first voltage compensation amounts of a first dead-time and a third dead-time of an AC voltage and a second inductor current value of the AC voltage based on polarities of the first to third current values, calculating fourth to sixth current values based on the second inductor current value, calculating second voltage compensation amounts of a second dead-time and a fourth dead-time of the AC voltage based on polarities of the fourth to sixth current values, and compensating a control reference signal of a processor based on the first and second voltage compensation amounts.