Parallel Switching Control for Minimum Pulse Width Limits
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Solution Overview
Problem
Switching apparatuses with multiple parallel switching devices face output distortion and increased losses due to differences in switching speed, leading to improper control and inefficient operation when the on-state holding time is short, resulting in switching failures and high power consumption.
Innovation Solution
Implementing a control method where the first switching device with a shorter minimum pulse width limit remains cut-off when the on-state holding time is less than its limit and performs switching when greater than or equal to the limit, while the second device performs switching operations when its on-state holding time meets or exceeds its minimum pulse width limit, with controlled flip times to manage turn-on and turn-off losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If multiple switching devices are simultaneously turned on to reduce on-resistance and losses, then power loss is reduced, but switching failures may occur when on-state holding time is short
Solution Approach 1:
The patent dynamically adjusts the switching control strategy based on the on-state holding time. When the holding time is sufficient, multiple switching devices are turned on to reduce losses. When the holding time is short, the control switches to a different mode to prevent switching failures, making the system adaptive to different operating conditions.
Solution Approach 2:
The patent changes the control parameters (switching signals) based on the on-state holding time. By monitoring the holding time parameter, the system adjusts whether to apply switching signals to the parallel-connected switching devices, thereby preventing switching failures while maintaining efficient operation when conditions permit.
2Productivity
If switching control is applied when on-state holding time is short, then switching operation is achieved, but output distortion occurs due to minimum pulse width limit
Solution Approach 1:
The patent applies preliminary anti-action by detecting the on-state holding time before applying switching control. When the holding time is shorter than the minimum pulse width limit, the system proactively prevents switching control from being applied, thereby avoiding the output distortion that would result from inadequate pulse width.
Solution Approach 2:
The patent uses feedback by continuously monitoring the on-state holding time and comparing it with the minimum pulse width limit. Based on this feedback, the control system decides whether to apply switching control to the parallel-connected switching devices, ensuring that switching operations are only performed when sufficient time is available, thus preventing output distortion.
3Loss of energy
If switching device with shorter minimum pulse width limit is controlled to switch, then switching loss is reduced, but output distortion increases when on-state holding time is short
Solution Approach 1:
The patent uses feedback by continuously monitoring the on-state holding time and comparing it with the minimum pulse width limit. Based on this feedback, the control system decides whether to apply switching control to the parallel-connected switching devices, ensuring that switching operations are only performed when sufficient time is available, thus preventing output distortion.
Solution Approach 2:
The patent dynamically adjusts the switching control strategy based on the on-state holding time. When the holding time is sufficient, switching control is applied to reduce losses. When the holding time is short, the control switches to a different mode to prevent output distortion, making the system adaptive to different operating conditions.
Data Source
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AI summary
This application provides a control method for a switching apparatus. The switching apparatus includes at least two switching devices connected in parallel, a minimum pulse width limit of the first switching device is less than a minimum pulse width limit of the second switching device, and the first switching device and the second switching device are in a turn-off state. The method includes: obtaining on-state holding time of the switching apparatus; controlling the at least two switching devices to remain in a cut-off state when the on-state holding time is less than the minimum pulse width limit of the first switching device; and controlling the first switching device to perform a switching operation when the on-state holding time is greater than or equal to the minimum pulse width limit of the first switching device. When the on-state holding time is less than the minimum pulse width limit of the first switching device, the first switching device is controlled to be turned off; and when the on-state holding time is greater than or equal to the minimum pulse width limit of the first switching device, the first switching device is controlled to perform a switching operation, thereby reducing a loss of the switching device and reducing output distortion.