Parallel Inverter Modules for Ripple Compensation
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Solution Overview
Problem
Existing power converting devices with high-frequency and low-frequency inverter modules face challenges in efficiently reducing ripples and dynamic response limitations due to the need for larger inductance and higher costs, especially when switching frequency is low, leading to increased ripple and reduced dynamic performance.
Innovation Solution
A power converting device and method that employs a high-frequency inverter module in parallel with a low-frequency inverter module, where the high-frequency inverter module compensates for the low-frequency ripple current by adjusting its duty ratio based on the low-frequency ripple current, allowing for effective ripple elimination and improved dynamic response without increasing inductance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If the inductance of the filter is increased to remove ripples, then the ripple reduction is improved, but the dynamic response decreases
Solution Approach 1:
The patent divides the single inverter system into two parallel inverter modules: a low-frequency inverter module for main power conversion and a high-frequency inverter module for ripple compensation. This segmentation allows each module to operate at optimized frequencies, with the high-frequency module specifically targeting ripple reduction without compromising the dynamic response of the overall system.
Solution Approach 2:
The patent changes the operating frequency parameter by introducing a high-frequency inverter module that operates at a higher switching frequency than the low-frequency module. This parameter change enables effective ripple filtering through the high-frequency operation, achieving ripple reduction without requiring increased inductance that would slow down the dynamic response.
2Stability of the object's composition
If the inductance of the filter is increased to reserve the decay range of the inductance, then the stability is improved, but the size and cost of the iron core increases
Solution Approach 1:
The patent segments the filtering function between two parallel inverter modules operating at different frequencies. The high-frequency inverter module handles the ripple compensation, which allows for smaller filter components since high-frequency ripples can be filtered more efficiently with smaller inductance values, thus reducing the size and cost of the iron core while maintaining stability.
Solution Approach 2:
By changing the operating frequency to high-frequency for the ripple compensation module, the patent reduces the required inductance value for effective filtering. High-frequency operation allows smaller inductors to achieve the same filtering effect, thereby reducing the size and cost of the iron core while maintaining system stability through the dual-module architecture.
3Ease of manufacture
If low-speed switching elements are used in the high-power inverter to reduce cost, then the cost is reduced, but the dynamic response is limited by the maximum switching frequency
Solution Approach 1:
The patent segments the inverter system into two modules with different functional roles: the low-frequency inverter module uses cost-effective low-speed switching elements for main power conversion, while the high-frequency inverter module uses high-speed switching elements specifically for ripple compensation. This segmentation allows the expensive high-speed elements to be used only where necessary, controlling overall cost while achieving high dynamic response through the high-frequency module.
Solution Approach 2:
The patent changes the switching frequency parameter by introducing a high-frequency inverter module that operates at a higher switching frequency than the low-frequency module. This allows the system to achieve fast dynamic response through the high-frequency module's capability, while the low-frequency module can use cheaper low-speed switching elements, thus balancing cost and performance.
4Ease of manufacture
If the switching frequency of the switching elements is lowered to reduce cost, then the cost is reduced, but the ripples will increase
Solution Approach 1:
The patent segments the ripple handling function to the high-frequency inverter module, which operates at a higher switching frequency specifically for ripple compensation. This allows the low-frequency inverter module to use lower switching frequencies for cost reduction, while the high-frequency module actively compensates for and eliminates ripples, thus achieving both cost reduction and effective ripple suppression through functional segmentation.
Solution Approach 2:
The patent changes the switching frequency parameter by introducing a high-frequency inverter module that operates at a higher frequency than the low-frequency module. This parameter change enables the low-frequency module to use cost-effective lower switching frequencies while the high-frequency module's higher switching frequency actively compensates for and reduces ripples, achieving both cost reduction and effective ripple suppression.
Data Source
AI summary
A power converting device with a high frequency inverter module compensating a low frequency inverter module is for transmitting a direct current voltage to an alternating current load module. The low frequency inverter module is controlled by a low frequency duty ratio. The high frequency inverter module is connected to the low frequency inverter module in parallel and controlled by a high frequency duty ratio. The low frequency inverter module is controlled according to the low frequency duty ratio to generate a first current. The high frequency duty ratio is adjusted according to a low-frequency ripple current. The high frequency inverter module is controlled according to the high frequency duty ratio to generate a second current, and the second current is for compensating ripples of the first current.