Drive Control Device Pre-Ignition Commutation Voltage Stability
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Solution Overview
Problem
Drive control devices experience significant voltage dips during commutation, leading to oscillations that can result in incorrect commutation, which is typically mitigated by increasing the capacitance of F3E capacitors, but this increases reactive current and space requirements.
Innovation Solution
Implementing a method where semiconductor switches are controlled with a pre-ignition angle before the normal activation time, creating a short circuit that allows current to commutate smoothly, thereby reducing voltage drops without increasing capacitor capacitance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the capacitance of F3E capacitors is increased to reduce voltage dips and oscillations, then the voltage stability during commutation is improved, but the reactive current component and space requirements increase
Solution Approach 1:
The patent applies preliminary action by triggering the semiconductor switch before the normal commutation time (pre-ignition). This advance triggering allows the switch to be already conductive when the commutation occurs, enabling the current to transfer smoothly without causing voltage dips. The pre-ignition angle is calculated based on the grid frequency and system parameters, ensuring the switch is ready in advance to handle the commutation current, thus avoiding oscillations without requiring larger capacitors.
2Stability of the object's composition
If the capacitance of F3E capacitors is increased to reduce voltage dips, then the oscillation tendency is reduced, but the device space and reactive current increase
Solution Approach 1:
The invention uses preliminary action by calculating and applying a pre-ignition angle that triggers the semiconductor switch in advance of the normal commutation time. This ensures the switch is already conductive when commutation occurs, allowing smooth current transfer and eliminating voltage dips that cause oscillations. By preparing the switch in advance, the system achieves stable commutation without requiring oversized capacitors, thereby reducing device space requirements.
3Reliability
If semiconductor switches are controlled with pre-ignition angle, then voltage drops during commutation are reduced, but the control complexity increases
Solution Approach 1:
The patent implements feedback by continuously monitoring the actual commutation behavior and adjusting the pre-ignition angle accordingly. The control system measures voltage and current parameters during commutation and uses this information to optimize the pre-ignition timing. This feedback mechanism ensures that the pre-ignition angle is precisely tuned to minimize voltage drops while avoiding excessive control complexity, as the adjustment is based on straightforward electrical parameter measurements.
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 reduces or eliminates severe voltage drops during commutation, minimizing oscillations without the need for larger capacitors, thus maintaining stable commutation.
Implementation Method 1
the control of individual semiconductor switches takes place by a corresponding control signal by a period of time expressed in the form of a predetermined or predeterminable pre-ignition angle before the determined control signal time
Data Source
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AI summary
A control signal time instant for each control signal is determined with control logic. The individual semiconductor switches are controlled with a corresponding control signal generated by the control logic at a respective control signal time instant. The individual semiconductor switches are controlled by the corresponding control signal in accordance with predetermined pre-ignition angle prior to the determined control signal time instant. Independent claims are included for the following: (1) computer program for regenerative operation of drive control facility; and (2) drive control facility.