Multiphase Driver Circuit Phase Current Balancing Feedback
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Solution Overview
Problem
Existing multiphase driver devices for semiconductor switches face imbalances in output currents due to variations in circuit element performance and increased gate capacitance, leading to increased current differences between phases, which existing solutions attempt to address by adding numerous circuits, resulting in a large circuit scale.
Innovation Solution
A multiphase driver device configuration that includes a first phase driver circuit with a monitoring transistor and resistor to output a reference voltage, and multiple phase driver circuits with comparators and regulating transistors to adjust source currents based on the reference voltage, ensuring balanced source currents without increasing circuit scale.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If large source currents are supplied to gates of IGBTs with increased gate capacitance, then drive capability is improved, but imbalance between phases is exacerbated
Solution Approach 1:
The patent implements feedback control by detecting the source current of each phase driver circuit and comparing it with a reference value. Based on the comparison result, the circuit adjusts the source current of each phase to reduce imbalances. This feedback mechanism enables the system to maintain balanced phase currents even when operating with large drive currents for high gate capacitance IGBTs.
Solution Approach 2:
The patent employs self-service by having each phase driver circuit automatically adjust its own source current based on detection and comparison with reference values. The circuit autonomously compensates for imbalances without requiring external intervention, thereby maintaining phase balance while delivering high drive capability.
2Stability of the object's composition
If numerous circuits are added to reduce imbalance between phases, then balance between phases is improved, but circuit scale increases
Solution Approach 1:
The patent merges multiple functions into a single integrated circuit structure. The detection circuit, comparison circuit, and current adjustment functionality are combined within the phase driver device itself, eliminating the need for separate external circuits. This integration achieves phase balance while avoiding an increase in overall circuit scale.
Solution Approach 2:
The patent implements multi-functionality by designing a unified circuit structure that performs both drive function and imbalance correction function. The same phase driver circuit that supplies gate signals also detects source current, compares it with reference values, and adjusts the current accordingly. This universal design avoids adding separate dedicated circuits for each function.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration effectively reduces imbalances between phases by matching source currents using a simple and efficient circuit design, allowing for adjustments to achieve balanced output currents without enlarging the circuit scale, thus improving the reliability and efficiency of semiconductor switch operations.
Implementation Method 1
a first monitoring resistor that converts a current flowing through the first monitoring transistor to a first voltage such that a value of the first voltage is proportional to the first source current
Implementation Method 2
a comparator that compares the second voltage to the reference voltage
Implementation Method 3
a first regulating transistor that adds a first regulating current to the second source current in accordance with an output of the comparator
Data Source
AI summary
A multiphase driver device includes: one phase driver circuit of a first type including a first monitoring transistor and a first monitoring resistor generating a first voltage that is proportional to a first source current supplied to a one of the plurality of semiconductor switches; and a plurality of phase driver circuits of a second type each including a second monitoring transistor and a second monitoring resistor generating a second voltage that is proportional to that a second source current supplied to corresponding one of the remaining semiconductor switches, each of the plurality of phase driver circuits of the second type further including a comparator that compares the second voltage to the reference voltage, and a first regulating transistor that adds a first regulating current to the second source current in accordance with an output of the comparator.