Semiconductor Pre-Charger Module Using MCT Switch
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Solution Overview
Problem
Conventional relay switches in battery systems, such as those used in electric vehicles, suffer from short lifespan, high weight, large volume, and inefficiency due to mechanical contact issues and high leakage currents, particularly when used for pre-charging, which can lead to system damage and power loss.
Innovation Solution
A semiconductor pre-charger module utilizing a MOS-controlled thyristor (MCT) with a low gate turn-on voltage and minimal leakage current, driven by a single pulse, is integrated into the battery system to replace traditional relays, featuring an isolation element for safe operation and efficient voltage control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a relay is used as a pre-charge switch, then high voltage and high current performance is achieved, but the device has heavy weight, large volume, short lifespan, and long turn-on time
Solution Approach 1:
The patent replaces the mechanical relay system with a semiconductor-based MCT (MOS-controlled thyristor) switch. This substitution eliminates mechanical contacts, arcs, and associated wear, thereby reducing weight and volume while extending lifespan and reducing turn-on time to microsecond levels.
2Volume of moving object
If a conventional MOSFET or IGBT is used as a pre-charge switch, then the device size is reduced, but leakage current increases and gate turn-on voltage becomes high
Solution Approach 1:
The patent changes the electrical parameters of the switch by using an MCT device with specific characteristics: low gate turn-on voltage (5V or less) and minimal leakage current (pA level). This parameter optimization resolves the contradiction between small size and low leakage current.
3Power
If a relay is used as a pre-charge switch, then high current capability is achieved, but the device generates heat and vibration causing short-circuits
Solution Approach 1:
The patent replaces the mechanical relay with a solid-state MCT switch that handles high current without mechanical contact. This eliminates vibration and reduces heat generation, preventing short-circuits while maintaining high current capability.
4Stability of the object's composition
If a pre-charge switch with fast turn-on time is used, then system stability is improved, but the device complexity increases
Solution Approach 1:
The MCT switch is designed to be self-latching, requiring only a brief trigger pulse to activate. Once turned on, it maintains conduction automatically without requiring continuous control signals, thereby achieving fast response with simple control circuitry.
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 semiconductor pre-charger module achieves high reliability, small size, light weight, and high efficiency by minimizing leakage current and simplifying the driving circuit, thereby extending system lifespan and reducing power loss while ensuring safe and efficient pre-charging operations.
Implementation Method 1
a semiconductor pre-charger module utilizing a MOS-controlled thyristor (MCT) with a low gate turn-on voltage and minimal leakage current
Data Source
AI summary
There is provided a battery system including: a controller; a main switch controlled by the controller to supply or cut off a voltage of a battery to a load; and a semiconductor pre-charger module including a semiconductor switch connected in parallel with the main switch and configured to supply or cut off the voltage of the battery to the load according to a control signal output from the controller, and a semiconductor switch driver configured to receive the control signal from the controller and output a single pulse signal for driving the semiconductor switch to turn on and off the semiconductor switch. Here, the semiconductor switch driver of the semiconductor pre-charger module includes an isolation element configured to electrically isolate the controller and the battery voltage, and the semiconductor switch of the semiconductor pre-charger module is a MOS-controlled thyristor (MCT).