Cascode Power Converter for Series Cell Voltage Balancing
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Solution Overview
Problem
Existing power conversion devices with multiple cell circuits connected in series face challenges in voltage balancing, requiring complex control systems, increased component count, and higher power consumption, leading to device size limitations and inefficiencies.
Innovation Solution
Implementing a power conversion device with cascode-connected switching elements and inductors, utilizing soft switching techniques and triangular current mode to equalize voltage amplitudes and phases across multiple cell circuits, reducing power loss and complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a master controller is provided to control each cell circuit in cooperation with slave controllers, then the operation stability of all cell circuits is improved, but the device complexity and number of components increase
Solution Approach 1:
Each cell circuit is equipped with a slave controller that autonomously controls its own output voltage and current, enabling self-regulation without requiring external master control. The controllers communicate through a simple signal line to achieve coordinated operation, eliminating the need for complex master controller architecture.
2Reliability
If a master controller is provided to stabilize operation of all cell circuits, then the operation stability is improved, but the number of components and wiring increases
Solution Approach 1:
The control functions are merged into distributed slave controllers, with each controller managing its own cell circuit. These slave controllers are connected through a single common signal line, reducing the need for multiple separate wiring connections that would be required with a centralized master controller architecture.
3Power
If output terminals of cell circuits are connected in series to generate high DC voltage, then the output voltage is improved, but the voltage balancing between cell circuits deteriorates
Solution Approach 1:
Slave controllers monitor the output voltage of their respective cell circuits and exchange information through a common signal line. Based on this feedback, each controller adjusts its control to maintain equal voltage distribution across all series-connected cell circuits, preventing voltage imbalance while achieving high output voltage.
4Adaptability or versatility
If the number of wires is increased to connect master controller to all cell circuits, then the control capability is improved, but the power consumption and device size increase
Solution Approach 1:
A single common signal line serves multiple functions by connecting all slave controllers, enabling them to exchange control information and coordinate their operation. This universal communication channel replaces the need for multiple dedicated wiring connections, reducing both power consumption and device size while maintaining full control capability.
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
Achieves stable, high-voltage output with reduced power loss and simplified control by ensuring uniform voltage and phase across multiple cell circuits, enabling efficient power conversion without complex wiring or additional components.
Implementation Method 1
utilizing soft switching techniques and triangular current mode to equalize voltage amplitudes and phases
Data Source
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AI summary
A power conversion device includes a first switching element and a first inductor connected in series between a first terminal and a second terminal, the first inductor and a second switching element being connected in series between the second and third terminals, a switching controller that alternately turns on and off the first and second switching elements, a first capacitor connected between the first and second terminals, and a second capacitor connected between the second and third terminals. When a first full-wave rectified voltage is input, switching frequencies of the first switching element and the second switching element, an inductance of the first inductor, a capacitance of the first capacitor, and a capacitance of the second capacitor are set so that a second full-wave rectified voltage having a voltage amplitude and a phase same as the voltage amplitude and the phase of the first full-wave rectified voltage is output.