Step-Up Converter Starting Current Limiting Method
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Solution Overview
Problem
Existing methods for limiting the starting current of a step-up-converter are inefficient, requiring direct current measurement and not effectively preventing high starting currents during incremental voltage increase.
Innovation Solution
A method that monitors the output voltage of a step-up-converter, temporarily disconnecting and reconnecting it to a DC voltage source to allow the coil to discharge, incrementally increasing the output voltage by switching the power switch on and off, until a predefined final value is reached, thereby limiting the starting current without direct current measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If direct current measurement is used to monitor starting current, then current limiting can be achieved, but device complexity and measurement effort increase
Solution Approach 1:
The patent uses output voltage as an intermediary parameter to indirectly control and limit starting current. Instead of directly measuring current, the system monitors output voltage changes and uses them to trigger disconnection events, which in turn limits the current through the coil discharge mechanism. This mediator approach simplifies the measurement system while maintaining effective current limiting.
Solution Approach 2:
The patent replaces the electrical measurement system (current sensors and measurement circuits) with a voltage-based control mechanism. By substituting direct current measurement with output voltage monitoring and using the inherent electrical characteristics of the coil discharge process, the system achieves current limiting without complex measurement hardware.
2Reliability
If continuous current monitoring is implemented, then starting current can be limited, but measurement precision requirements and system effort increase
Solution Approach 1:
The patent uses output voltage as an intermediary that naturally reflects the charging state of capacitors and the current flow through the coil. By monitoring voltage changes rather than current directly, the system achieves reliable starting current control with simpler and less precise measurement requirements, as voltage can be measured more easily and with higher precision using standard voltage dividers or ADC circuits.
3Reliability
If incremental voltage increase is used to limit starting current, then current peaks are prevented, but time to reach final voltage increases
Solution Approach 1:
The patent implements periodic switching of the power switch to achieve incremental voltage increase. The system repeatedly connects and disconnects the DC voltage source in controlled cycles, allowing the coil to discharge during each disconnection phase. This periodic action limits starting current by preventing continuous high current flow while progressively charging the output capacitor to the final voltage.
Solution Approach 2:
The patent performs preliminary discharge of the coil during each disconnection phase before the next connection. By预先 (in advance) allowing the coil to discharge during the off-period, the system prepares for the next voltage increment while ensuring current is already reduced, thus limiting starting current for each subsequent connection cycle.
4Productivity
If the power switch remains closed after reaching final voltage, then continuous operation is maintained, but high starting currents may occur if disconnected and reconnected
Solution Approach 1:
The patent performs preliminary discharge of the coil during each disconnection interval, including after the final voltage is reached. If the system is disconnected and needs to be reconnected, the preliminary discharge action during the disconnection period ensures that when power is restored, the coil current is already reduced, preventing high starting currents upon reconnection.
Solution Approach 2:
The patent maintains the periodic switching behavior even after reaching final voltage in certain operational modes. This periodic action ensures that if disconnection occurs, the coil has time to discharge during the off-period, and upon reconnection, the incremental voltage increase process resumes with controlled current, preventing current spikes during reconnection events.
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 effectively limits starting currents with reduced effort, preventing high current values by allowing the coil to discharge between connections, ensuring the output voltage reaches a safe final value without alarming currents, thus enhancing the efficiency of the step-up-converter operation.
Implementation Method 1
a time period is allowed, in which the coil (4) of the step-up-converter discharges
Data Source
AI summary
The disclosure relates to a method for limiting the starting current of a step-up-converter that is supplied by a DC voltage source. The step-up converter has a first capacitor, a coil connected in parallel to the first capacitor, a second capacitor connected to the coil in series, and a switch connected to the second capacitor in parallel and connected to the coil in series. In a first step, an output voltage of the circuit is measured and the step-up converter is connected to the DC voltage source by closing a power switch that is connected in series to the first capacitor. In a second step, the power switch is opened upon the output voltage increasing by more than a predefined threshold and is maintained open for a predefined time. The first and second steps are repeated until the output voltage reaches a predefined final value.