Solid-State Power Controller Pre-Charge for DC Bus Inrush Suppression
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Solution Overview
Problem
Inrush currents and voltage spikes during the connection of capacitive loads to a DC bus in more electric aircraft (MEA) and all electric aircraft (AEA) systems can cause damage to the system, and traditional methods with electro-mechanical switches are not suitable for solid-state power controllers (SSPCs).
Innovation Solution
A solid-state power controller that uses a semiconductor switch operated in an active region to pre-charge capacitive loads, suppressing inrush currents and voltage spikes by generating pulsed driver signals with different voltage levels to control the switch's operation between active and saturated regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a semiconductor switch is used to connect capacitive loads to a DC bus, then the response time is reduced and reliability is improved, but inrush current and voltage spikes occur during turn-on
Solution Approach 1:
The patent applies preliminary action by pre-charging the capacitive load through a controlled charging process before full connection to the DC bus. The controller activates the semiconductor switch in a preliminary stage with limited current, then gradually transitions to full power connection, preventing inrush current damage while maintaining the reliability benefits of solid-state switching.
Solution Approach 2:
The patent implements dynamics by dynamically controlling the semiconductor switch operation through multiple stages. The controller adjusts the switch operating parameters in real-time during the connection process, transitioning from a controlled charging phase to full power transmission, thereby adapting the system behavior to prevent harmful inrush currents while maintaining fast response characteristics.
2Object-affected harmful factors
If a separate pre-charge resistor and contactor are used during initial period, then inrush current is suppressed, but device complexity and size increase
Solution Approach 1:
The patent applies merging by combining the pre-charge function and main power transmission function into a single semiconductor switch device. The controller integrates both the pre-charge control and full power connection control within one solid-state switch, eliminating the need for separate pre-charge resistors and mechanical contactors, thereby reducing device complexity while maintaining inrush current suppression capability.
Solution Approach 2:
The patent implements universality by designing the semiconductor switch to perform multiple functions: it acts as both the pre-charge switch and the main power transmission switch. The single device handles both the initial controlled charging phase and the subsequent full power connection, reducing the overall number of components and simplifying the circuit architecture.
3Object-affected harmful factors
If additional circuitry such as buck converter is connected in parallel with semiconductor device, then soft-start function is achieved, but weight and size of system increase
Solution Approach 1:
The patent applies extraction by removing the need for additional external circuitry such as buck converters. Instead, the soft-start function is extracted and integrated directly into the control logic of the semiconductor switch itself. The controller manages the gradual charging process through intelligent control of the existing switch, eliminating the weight and size burden of separate voltage regulation circuits.
Solution Approach 2:
The patent implements self-service by enabling the semiconductor switch to perform its own soft-start function without requiring external assistance from additional circuitry. The switch, controlled by the integrated controller, autonomously manages the gradual charging process and voltage spike suppression, making the system self-sufficient and eliminating the need for extra weight-bearing components.
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 effectively suppresses inrush currents and voltage spikes during the pre-charging of capacitive loads, preventing damage to the system and allowing for efficient and reliable operation of power converters in aerospace applications.
Implementation Method 1
a first pulsed driver signal which operates the at least one semiconductor switch in an active region
Implementation Method 2
a second pulsed driver signal which operates the at least one semiconductor switch in a saturated region
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A solid state power controller (1) for limiting and/or breaking an electrical current flowing through a power transmission line. The solid state power controller (1) comprises at least one semiconductor switch (S1; S11-S16) with a control terminal (G); a controller (20) generating a pulsed signal; and a gate driver circuit (10) receiving the pulsed signal and configured to generate a pulsed driver signal which is applied to the control terminal (G) of the at least one semiconductor switch (S1; S11-S16). The gate driver circuit (10) comprises a gate driver (11) receiving from the controller (20) the pulsed signal and providing a pulsed output signal; and driver signal generating means (12, 13; 14, 15) configured to be operable in a first state and a second state, the first and second states controlled by the controller (20). The driver signal generating means (12, 13; 14, 15) receive the gate driver pulsed output signal and are configured to generate in the first state a first pulsed driver signal which operates the at least one semiconductor switch (S1; S11-S16) in an active region, and to generate in the second state a second pulsed driver signal which operates the at least one semiconductor switch (S1; S11-S16) in a saturated region. The controller (20) is configured to set the driver signal generating means (12, 13; 14, 15) in the first or second state depending on a voltage level signal received by the controller.