Series Semiconductor Switch Control for Balanced High-Voltage Sharing
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Solution Overview
Problem
Existing circuit arrangements for semiconductor switches in high-power applications face challenges in maintaining even voltage distribution and minimizing wear, particularly when operating at voltages close to the maximum permissible blocking voltage, leading to uneven power losses and asymmetric component degradation.
Innovation Solution
A circuit arrangement featuring a series connection of semiconductor switches with individually controlled drive circuits, where the switching behavior of each control circuit can be adjusted via digital parameters to balance voltage distribution and manage switching losses, incorporating a voltage monitoring device to ensure voltage limits are not exceeded and a master-slave configuration for efficient communication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a higher direct voltage is used to provide high power output, then the power delivery capability is improved, but the maximum blocking voltage capability of the semiconductor power switches is exceeded and component wear increases
Solution Approach 1:
The patent divides a single high-voltage switching task into multiple lower-voltage switching tasks by connecting semiconductor power switches in series. Each switch handles a portion of the total voltage, allowing the system to achieve high power output without any single switch exceeding its blocking voltage capability. This segmentation resolves the contradiction by enabling high power delivery while maintaining switch reliability within safe operating limits.
2Loss of energy
If semiconductor switches operate at voltage close to maximum permissible blocking voltage, then the power efficiency is improved, but the component wear increases and lifespan decreases
Solution Approach 1:
The patent applies local quality by distributing the voltage stress unevenly across series-connected switches initially, then using active control to balance the voltage distribution. Each switch operates at an optimized voltage level that balances efficiency and longevity, rather than all switches operating at maximum voltage. This allows the system to maintain high power efficiency while preventing any single component from experiencing excessive stress that would reduce its lifespan.
3Stress or pressure
If series connection of semiconductor switches is implemented to handle high voltage, then the voltage handling capability is improved, but the voltage distribution becomes uneven and control complexity increases
Solution Approach 1:
The patent implements feedback control by continuously monitoring the voltage across each semiconductor switch in the series connection and using this information to adjust the switching signals. The control circuits exchange information about actual voltage distribution and adapt their switching behavior to achieve balanced voltage sharing. This feedback mechanism resolves the contradiction by automatically managing the complexity of controlling multiple series switches while maintaining even voltage distribution and high voltage handling capability.
4Stability of the object's composition
If individual control circuits are provided for each semiconductor switch to balance voltage distribution, then the voltage balancing is improved, but the system complexity and communication requirements increase
Solution Approach 1:
The patent merges the control functions by having control circuits exchange information and coordinate their switching actions collectively. Rather than completely independent control circuits, the system uses interconnected control circuits that share voltage distribution information and synchronize their operations. This merging approach reduces the overall system complexity while maintaining stable and balanced voltage distribution across the series-connected semiconductor switches.
Data Source
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AI summary
In order to be able to provide a high power, for example for an electrical machine, by means of an inverter, a higher operating voltage (Uzk) can be used. However, this possibility is limited by the maximum reverse voltage capability of semiconductor switches (44, 78) of the inverter. The object of the present invention is to provide a low-maintenance switching apparatus with which a current can be switched even at relatively high powers. The circuit arrangement according to the invention has a series circuit (80) comprising at least two semiconductor switches (44, 78), of which each is connected to a respective actuation circuit (42, 82) by means of its control input. In the case of at least one of the actuation circuits (42, 82), the switching behaviour thereof can be defined by at least one digital switching parameter. The value (K1(1)*Uzk, K2(1)*Uzk, K1 (n) *Uzk, K2 (n) *Uzk) of the switching parameter can be varied, and therefore the switching behaviour can be adjusted during operation, that is to say between two switching processes.