Inverter Gate Driving With Faster Current Than Voltage Slew
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Solution Overview
Problem
Inverters and converters experience significant switching losses due to the non-zero power consumption when transistors switch between on and off, and there is a risk of electrical breakdown from excessive voltage change rates.
Innovation Solution
The inverter and converter designs include a driver with current and voltage adjustment elements that control the time change rates of current and voltage differently, with the current change rate being greater than the voltage change rate to minimize switching losses and reduce the risk of electrical breakdown.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the transistor switches between on and off states with equal time change rates for both current and voltage, then the switching control is simple, but switching losses increase due to non-zero power consumption during transition
Solution Approach 1:
The patent applies parameter changes by differentiating the time change rates of current and voltage during transistor switching. Specifically, it controls the current time change rate (di/dt) to be greater than the voltage time change rate (dv/dt) through the driver circuit design, which reduces the overlap period when both voltage and current are non-zero during switching transitions, thereby reducing switching losses.
Solution Approach 2:
The patent implements dynamics by making the switching control adaptive and differentiated. The driver circuit dynamically adjusts the switching characteristics to achieve unequal time change rates for current and voltage, transforming the static switching control into a dynamic process that optimizes power loss reduction during transitions.
2Loss of energy
If the voltage change rate is increased to improve switching speed, then switching loss is reduced, but the risk of electrical breakdown in motor winding increases
Solution Approach 1:
The patent resolves this contradiction by changing the parameter relationship between voltage and current time change rates. Instead of increasing voltage change rate alone, it establishes that current time change rate should be greater than voltage time change rate (di/dt > dv/dt), which reduces switching loss while limiting voltage spike risks to motor winding breakdown.
Solution Approach 2:
The driver circuit acts as an intermediary that mediates between the transistor switching action and the motor winding. By controlling the current to change faster than voltage through the driver's internal circuitry, it reduces switching losses while protecting the motor winding from excessive voltage stress.
3Loss of energy
If the current change rate is increased to reduce switching loss, then energy efficiency improves, but control precision becomes more difficult to maintain
Solution Approach 1:
The patent addresses control precision by establishing a specific parameter relationship where current time change rate is controlled to be greater than voltage time change rate. This differentiated control approach maintains measurability and detectability while optimizing energy efficiency, as the driver circuit is designed to inherently manage this parameter relationship.
Data Source
AI summary
An inverter includes: a high electric potential input terminal, a low electric potential input terminal, an output terminal that outputs AC power, a transistor pair, a driver that performs complementary switching control of the transistor pair. The driver includes a current adjustment element that adjusts the channel current and a voltage adjustment element that adjusts the channel voltage of the transistor pair, and adjusts, in the switching control of the transistor pair, the time change rate of the channel current to be larger than the time change rate of the channel voltage.