Power Converter Control Device for Motor Noise Reduction
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Solution Overview
Problem
Existing direct power converter systems fail to efficiently drive motors while minimizing noise, as they do not adequately address the noise generated by mechanical vibrations and fluctuations in motor rotational speed.
Innovation Solution
A power converter control device that adjusts the compensation rate based on motor rotational speed to reduce noise and optimize efficiency, by setting a higher compensation rate during specific rotational speed ranges to minimize noise and a lower rate during others to reduce power buffer circuit losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a high compensation rate is used to reduce noise in the power buffer circuit, then noise suppression is improved, but power losses increase and efficiency decreases
Solution Approach 1:
The patent applies dynamics by making the compensation rate adjustable and variable based on operating conditions. The control device dynamically changes the compensation rate according to the rotational speed of the motor, transitioning between different compensation modes to optimize both noise suppression and efficiency under varying operational states.
Solution Approach 2:
The patent implements parameter changes by modifying the compensation rate parameter based on detected rotational speed. When rotational speed falls within predetermined ranges associated with noise peaks, the compensation rate is increased to suppress noise; otherwise, it is reduced to minimize power losses, thus adapting system parameters to operational conditions.
2Object-affected harmful factors
If the compensation rate is increased to minimize power ripple and noise, then noise suppression is improved, but the size and cost of the power buffer circuit increase
Solution Approach 1:
The control device dynamically adjusts the compensation rate based on real-time rotational speed detection, enabling the power buffer circuit to operate with variable compensation levels rather than fixed high compensation, thus reducing the required circuit size while maintaining noise suppression when needed.
Solution Approach 2:
By changing the compensation rate parameter according to operational conditions, the system achieves noise suppression only when necessary (when rotational speed indicates noise peaks), allowing for a more compact and cost-effective power buffer circuit design that does not require continuous high-level compensation capability.
3Object-affected harmful factors
If a fixed high compensation rate is used throughout all operating conditions, then noise is consistently suppressed, but efficiency decreases across all operating modes
Solution Approach 1:
The system transitions from static to dynamic control by continuously monitoring rotational speed and adjusting the compensation rate in real-time, enabling efficient operation across varying loads while maintaining noise suppression capability when operational conditions indicate noise generation.
Solution Approach 2:
The compensation rate parameter is varied based on detected rotational speed ranges, implementing high compensation only when noise peaks are anticipated (within predetermined ranges) and low compensation during other operating modes, thus optimizing the balance between noise suppression and efficiency across the full operating spectrum.
4Object-affected harmful factors
If the power buffer circuit is designed with high compensation capability to handle all noise scenarios, then noise suppression is ensured, but device complexity and cost increase
Solution Approach 1:
The control device introduces dynamic adjustment capability that allows a simpler power buffer circuit to achieve noise suppression when needed by varying the compensation rate, eliminating the requirement for an overly complex circuit designed for continuous maximum compensation.
Solution Approach 2:
By implementing parameter-based control of the compensation rate, the system enables a relatively simple power buffer circuit to adapt its performance characteristics through control signals, achieving noise suppression capability without requiring complex hardware modifications or oversized components.
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
A direct-power converter control device that enables driving of a motor with high efficiency while suppressing noise is provided. Ripple power having a first variation range is input into a DC link (DC power supply lines (LH, LL)). Buffer power is provided and received between the DC link and a power buffer circuit (4), so that the DC link outputs DC power having a second variation range smaller than the first variation range. An inverter (5) receives the DC power as an input, and outputs AC power to a motor (6). A power control unit (11) controls the power buffer circuit and the inverter on the basis of a compensation rate (k) that sets the second variation range. A compensation rate setting unit (12) performs a setting in which the compensation rate (k) when a rotational speed (ωm) of the motor (6) belongs to any of a plurality of first predetermined ranges is higher than the compensation rate (k) when the rotational speed (ωm) belongs to a second predetermined range other than the plurality of first predetermined ranges.