Power Converter Common DC Link for Parallel Machine Operation
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Solution Overview
Problem
Existing power converter topologies, such as the Bordline CC1500 DE, restrict the type of power supply and rectifier circuit topology when multiple electrical machines are operated in parallel, leading to issues like undesired compensating currents and limitations in bidirectional energy flow.
Innovation Solution
A power converter design that allows two converters to share a common DC voltage intermediate circuit, using semiconductor switches for indirect energy supply and eliminating AC-side equalizing currents, enabling the use of various power supplies and rectifier topologies without requiring all converters to connect to the same power supply.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If passive rectifier circuits are used to avoid compensating currents between parallel converters, then reliability is improved, but adaptability deteriorates because bidirectional energy flow is prevented
Solution Approach 1:
The invention segments the power supply architecture by introducing a common DC voltage intermediate circuit that serves as a shared energy buffer between parallel converters. Each converter connects to this common DC circuit independently, allowing individual rectifier circuits to be segmented and configured separately while maintaining system stability through the shared DC link.
Solution Approach 2:
The common DC voltage intermediate circuit acts as an intermediary between the parallel converters and the power supply. This intermediate circuit decouples the converters from direct AC-side interactions, eliminating compensating currents while enabling flexible power supply connections through the DC side.
2Productivity
If converters are connected in parallel on the rectifier side to operate multiple electrical machines, then productivity is improved, but device complexity increases due to matching requirements
Solution Approach 1:
The invention merges the DC voltage intermediate circuits of multiple parallel converters into a single common DC voltage intermediate circuit. This consolidation simplifies the overall system architecture by eliminating the need for separate DC circuits and matching rectifier topologies, while still enabling multiple electrical machines to be operated in parallel.
3Ease of manufacture
If a common power supply is used for parallel converters to reduce device complexity, then ease of manufacture is improved, but adaptability deteriorates because bidirectional energy flow is restricted
Solution Approach 1:
The common DC voltage intermediate circuit provides universal functionality by serving as a shared energy buffer that accommodates various power supply types and configurations. It enables both unidirectional and bidirectional energy flow scenarios, supporting diverse energy supply options including asynchronous machines, while maintaining manufacturing simplicity through a standardized common DC link architecture.
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 design allows for flexible power supply options, eliminates AC-side equalizing currents, and reduces the need for additional components, resulting in a more compact and cost-effective power converter that can operate with both single-phase and three-phase energy supplies.
Implementation Method 1
the first DC voltage side pole can be at least connected to the third DC voltage side pole via a first current path and the second DC voltage side pole can be connected to the fourth DC voltage side pole via a second current path which current paths can be at least connectable, wherein the first current path and the second current path comprises a semiconductor switch
Data Source
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AI summary
The invention relates to a power converter (10) for operating a first electric machine (12) and a second electric machine (14), comprising a first converter (16), a second converter (18), and a first connection (21), a second connection (22), and a third connection (23) for connecting the power converter (10) to a three-phase energy supply (60), wherein the first converter (16) comprises a first rectifier circuit (31) and a second rectifier circuit (32) and the second converter (18) comprises a third rectifier circuit (33), wherein the first rectifier circuit (31) has a first alternating-current-side pole (51) and a second alternating-current-side pole (52), the second rectifier circuit (32) has a third alternating-current-side pole (53) and a fourth alternating-current-side pole (54), and the third rectifier circuit (33) has a fifth alternating-current-side pole (55) and a sixth alternating-current-side pole (56), the first rectifier circuit (31) and the second rectifier circuit (32) are connected in parallel on the direct voltage side and are connected to a common first direct-voltage-side pole (41) and to a common second direct-voltage-side pole (42), wherein the third rectifier circuit (33) is connected on the direct voltage side to a third direct-voltage-side pole (43) and to a fourth direct-voltage-side pole (44), wherein the first direct-voltage-side pole (41) at least can be connected to the third direct-voltage-side pole (43) by means of a first current path (36) and the second direct-voltage-side pole (42) at least can be connected to the fourth direct-voltage-side pole (44) by means of a second current path (37), wherein at least the first current path (36) or the second current path (37) comprises a semiconductor switch (64).