Two-Quadrant Converter Filter for Power Supply Ripple
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Solution Overview
Problem
Existing filter devices for power supply connections struggle to effectively reduce ripple in intermediate circuit voltage and prevent oscillations, as they require complex components like chokes and capacitors, and fail to completely eliminate disruptive harmonics, leading to instability and increased demands on dielectric strength.
Innovation Solution
A filter device comprising a backup capacitor and a two-quadrant controller with a control circuit that generates control signals based on bandpass-filtered AC voltage components, forming a series resonant circuit to dampen disruptive AC components, thereby reducing ripple and oscillations with less overall effort and resource usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a series resonant circuit is used to eliminate disruptive harmonics, then the AC voltage component is reduced, but the voltage increase at resonance places particular demands on the dielectric strength of the capacitance
Solution Approach 1:
The patent extracts the disruptive AC voltage component from the power supply connection by using a parallel resonant circuit that specifically targets and isolates the harmonic frequency, allowing it to be compensated separately without affecting the main power delivery
Solution Approach 2:
The patent applies counter-action by generating a compensation current that is 180 degrees out of phase with the disruptive harmonic, effectively canceling it out. The parallel resonant circuit creates an opposing voltage that counterbalances the harmful AC component
2Device complexity
If an uncontrolled rectifier is used to feed the intermediate circuit, then the system is simpler, but harmonics occur under load which are particularly disruptive
Solution Approach 1:
The patent introduces a parallel resonant circuit as an intermediary element between the rectifier and the load. This mediator specifically targets the harmonic frequency generated by the uncontrolled rectifier and provides a path for it to be compensated, allowing the simple rectifier to continue operating while its harmful effects are neutralized
Solution Approach 2:
The patent implements feedback by continuously monitoring the AC voltage component at the harmonic frequency and adjusting the compensation current accordingly. The control system detects the disruptive harmonics and automatically generates the counteracting current to maintain cancellation
3Productivity
If regulated, highly dynamic drives are used, then the drive performance is improved, but the time delay causes mapping of harmonics to torque which cannot be avoided to a satisfactory extent
Solution Approach 1:
The patent applies preliminary action by compensating for the AC voltage component before it can be mapped to torque through the motor drive. By eliminating the harmonic voltage distortion at the power supply level, the subsequent drive stages operate with cleaner input, preventing the propagation of harmonics to the torque output
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 reduces AC voltage ripple and oscillations in power supply connections, improving stability and reducing the need for complex components, while maintaining efficient operation and cost-effectiveness.
Implementation Method 1
the voltage of the power supply connection is rectified by means of a two-quadrant converter into a back-up voltage for charging a back-up capacitor
Implementation Method 2
the backup voltage is inverted into a backup current using the two-quadrant controller
Implementation Method 3
forming a series resonant circuit to dampen disruptive AC components, thereby reducing ripple and oscillations
Data Source
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AI summary
To improve the voltage (Ud) of a power supply connection (SVV), a filter device (FV) comprises a decoupling capacitor (Cst), a two-quadrant converter (Z), and a control circuit (S) for generating (120) at least one first control signal (S1) for the two-quadrant converter (Z). The two-quadrant converter (Z) has a decoupling voltage connection (SSA) connected to the decoupling capacitor (Cst). The two-quadrant converter (Z) also has an AC voltage connection (WSA) for parallel connection with the power supply connection (SVV). The control circuit (S) is configured to generate the first control signal (S1) taking into account a first AC voltage component (WF1) of the voltage (Ud) of the power supply connection (SVV). The control circuit (S) includes a first bandpass filter (BPF1) for filtering the first AC voltage component (WF1) of the voltage (Ud) of the power supply connection (SVV).Furthermore, a power supply device (SV) with a filter device (FV) according to the invention and a corresponding method (100) for improving a voltage (Ud) of the power supply connection (SVV) are provided.