High-Voltage Bus Discharge Circuit with Bi-Stable Switch
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing power inverter systems face challenges in efficiently discharging electrical energy stored on high-voltage buses, particularly when the system is not in operation, which can lead to instability and potential over-discharge issues.
Innovation Solution
A passive discharge circuit is introduced, comprising a discharge switch and resistor connected in series between the positive and negative conductors of the high-voltage bus, controlled by a bi-stable switch and trigger device, allowing for automatic and rapid discharge without external power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a discharge circuit is implemented to discharge electrical energy stored on the high-voltage bus, then system stability is improved and over-discharge is prevented, but device complexity increases due to additional components
Solution Approach 1:
The discharge switch is integrated into the existing power inverter circuit architecture, merging the discharge function with the bulk capacitor and high-voltage bus structure. This combination allows the discharge circuit to share physical and control resources with the power inverter system, reducing overall device complexity while maintaining reliability improvements.
Solution Approach 2:
The discharge circuit is designed to operate autonomously using the existing high-voltage bus energy to control the discharge process. The circuit automatically activates when voltage thresholds are exceeded, using the stored energy itself to trigger and sustain the discharge operation without requiring external control systems, thereby improving reliability without proportionally increasing complexity.
2Speed
If a rapid discharge mechanism is implemented to quickly discharge high-voltage bus energy, then discharge speed is improved and system stability is enhanced, but energy loss increases due to the rapid discharge process
Solution Approach 1:
The discharge resistor value is carefully selected to optimize the discharge time constant, achieving rapid discharge while controlling energy loss. By adjusting the resistance parameter, the system achieves fast discharge speed for stability improvement while the resistor value is tuned to minimize excessive energy dissipation, balancing speed and energy loss trade-offs.
3Ease of operation
If a discharge circuit with switch and resistor is added to the power inverter system, then the ability to control discharge is improved, but manufacturing complexity increases
Solution Approach 1:
The discharge switch and resistor components are selected to serve multiple functions within the power inverter system. The discharge circuit can operate in various modes (controlled discharge, automatic discharge, emergency discharge) and shares components with the existing power conversion architecture, making the system easier to manufacture by using standardized multi-functional components rather than dedicated single-purpose parts.
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
The solution enables quick, automatic, and energy-efficient discharge of high-voltage bus energy, preventing over-discharge and ensuring system stability during shutdown, vehicle operation, or emergency conditions like airbag deployment, without requiring active control or energy consumption.
Implementation Method 1
a discharge switch electrically connected in series with a discharge resistor between positive and negative conductors of the high-voltage bus
Data Source
AI summary
A discharge circuit for a high-voltage bus that is electrically connected to a high-voltage DC power source is described. The discharge circuit includes a discharge switch electrically connected in series with a discharge resistor between positive and negative conductors of the high-voltage bus, and the discharge switch includes a gate. A bi-stable switch includes a control gate, an input line that is electrically connected to the high-voltage bus and an output line that is electrically connected to the gate of the discharge switch. A trigger device is in communication with the control gate of the bi-stable switch. The input line of the bi-stable switch is electrically connected to the high-voltage bus, and the discharge switch is controllable to a closed state to provide an electric current flow path through the discharge resistor between the positive and negative conductors of the high-voltage bus in response to an activation signal.