Power Supply Unit Starting Voltage via Magnetic Remanence
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Solution Overview
Problem
Power supply units for motor vehicle electrical systems face challenges in managing high inrush currents during the charging of DC link capacitors, which can lead to component damage and inefficiencies, particularly when the generator is not operational.
Innovation Solution
The method utilizes the magnetic remanence of the rotor winding core to generate a starting voltage without external excitation, enabling the charging of DC link capacitors and powering of other components, thereby eliminating the need for additional energy sources and reducing the risk of high inrush currents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If DC link capacitors are isolated from the vehicle electrical system to avoid leakage currents, then reliability is improved, but device complexity increases due to switching requirements and inrush current management
Solution Approach 1:
The patent applies preliminary action by pre-charging the DC link capacitors using the vehicle battery before generator connection. This ensures the capacitors are already charged when the generator is connected, eliminating inrush currents and the need for complex switching control during generator startup.
2Reliability
If series connection of ohmic or inductive load is used to limit inrush current, then reliability is improved by preventing component damage, but device complexity increases and manufacturing cost rises
Solution Approach 1:
The patent eliminates the need for series connection of ohmic or inductive loads by pre-charging the DC link capacitors before generator connection. The capacitors are charged to the required voltage level using the vehicle battery, so when the generator is connected, no inrush current occurs and no additional limiting components are needed.
3Reliability
If DC voltage converter is used to regulate charging current and voltage, then reliability is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent eliminates the need for DC voltage converters by pre-charging the DC link capacitors to the required voltage level before generator connection. The capacitors are charged using the vehicle battery, and once charged, the generator can be connected without requiring additional voltage regulation components.
4Object-affected harmful factors
If clocking of voltage at DC link capacitors is used, then inrush current is limited, but device complexity increases and manufacturing cost rises
Solution Approach 1:
The patent eliminates the need for voltage clocking control circuitry by pre-charging the DC link capacitors before generator connection. The capacitors are charged to the required voltage level using the vehicle battery, so when the generator is connected, the voltage is already stable and no clocking control is needed.
5Reliability
If adapted dimensioning of all components is used to prevent damage from high charging current, then reliability is improved, but manufacturing cost increases
Solution Approach 1:
The patent eliminates the need for adapted dimensioning of components to withstand high charging currents by pre-charging the DC link capacitors before generator connection. Since the capacitors are already charged, no high inrush current occurs, and standard component specifications can be used, reducing manufacturing cost.
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 approach provides an autonomous energy source that can precharge capacitors and power electronics independently, reducing the risk of component damage and eliminating the need for additional voltage sources, while also allowing for cost savings by eliminating the need for components like resistors and transistors.
Implementation Method 1
The present invention makes use of a magnetic remanence of the rotor (in particular of the winding core) to generate a starting voltage without external excitation
Data Source
AI summary
A method for operating a power supply unit for an electrical system of a motor vehicle, the power supply unit having an electric generator having a stator having a stator winding and a rotor having a rotor winding, as well as a field current controller assigned to the rotor winding for selecting the setpoint of the current flowing through the rotor winding; the electric generator being set into rotation without a current being specified by the rotor winding, thereby generating a starting voltage; at least one component of the power supply unit or of the vehicle electrical system being energized by the starting voltage.