Power Module Control Circuit for Dead-Time Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing power modules with dead time compensation techniques face challenges in reducing the number of input signals and compensating for output voltage distortion, as described in Japanese Patent Laying-Open No. 2001-327171 does not explicitly incorporate dead-time compensation into the power module design.
Innovation Solution
A power module with a power conversion unit comprising switching-element pairs and diodes, along with a control circuit that receives command signals and a shared enable signal, performs all-off control, dead-time addition control, and dead-time compensation control to minimize input signals and correct output voltage distortion by adjusting switching element states based on load current polarity and command signal changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If dead time is added to PWM signals to prevent simultaneous conduction of switching elements, then switching safety is improved, but output voltage distortion increases
Solution Approach 1:
The control circuit preemptively extends the conduction period of switching elements beyond the normal PWM signal duration to compensate for the voltage loss caused by dead time. By calculating the expected voltage distortion in advance and applying compensatory extension, the system maintains accurate output voltage control while preserving the necessary dead time for safe switching operations.
Solution Approach 2:
The system incorporates feedback mechanisms that monitor the actual output voltage and switching states, then adjust the switching element conduction timing accordingly. The control circuit uses information about dead time duration and load conditions to dynamically modify the compensation strategy, ensuring accurate voltage control while maintaining switching safety.
2Volume of moving object
If the number of input signals is reduced for miniaturization, then device size is reduced, but control flexibility is worsened
Solution Approach 1:
The control circuit merges multiple control functions into a unified architecture that accepts reduced input signals while maintaining full control capability. By integrating dead time compensation, PWM generation, and switching control into a single control unit that processes fewer input signals, the system achieves miniaturization without sacrificing control flexibility.
Solution Approach 2:
The control circuit is designed with multi-functionality to handle various control tasks using a minimal set of input signals. It can perform normal PWM control, dead time addition, dead time compensation, and all-off control using the same control pathways, thereby reducing the number of dedicated input signals required while maintaining adaptability across different operating conditions.
Data Source
AI summary
A power module including: a power conversion unit including N switching-element pairs; and a control circuit. The control circuit receives N command signals, which correspond respectively to the N switching-element pairs, and a shared enable signal. The control circuit is configured to, when the enable signal is negated, execute all-off control of turning off all of the switching elements constituting the power conversion unit, and when the enable signal is asserted, execute normal control, dead-time addition control, and dead-time compensation control for each of the switching-element pairs per period of a corresponding command signal.