Converter Controller Redundancy via Resolver Data Sharing
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Solution Overview
Problem
High-power electric drive systems with multiple machines and resolvers face reliability issues due to the potential failure of resolver-RDC-converter controller combinations, leading to increased costs and system downtime, as each resolver requires AC excitation and analog processing, and lacks redundancy for fault tolerance.
Innovation Solution
A system with multiple resolvers and converter controllers connected via communication buses, where each converter controller activates its resolver-to-digital converter (RDC) based on priority, sharing digital shaft information to ensure redundancy and fault tolerance, allowing continued operation even if one RDC fails.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single resolver-RDC-converter controller combination is used for each electric machine, then the system structure is simple and cost-effective, but the system reliability deteriorates because any failure renders the whole electric drive system inoperable
Solution Approach 1:
Multiple converter controllers are merged into a single coordinated control system that shares shaft information through communication buses. The controllers work together as an integrated unit, allowing redundancy where multiple controllers can support each other's functions, particularly in providing shaft position and speed information to power converters.
Solution Approach 2:
Duplicate resolver-RDC-converter controller combinations are implemented to create redundant copies of the critical measurement and control chain. Each controller has its own resolver and RDC, ensuring that if one copy fails, another can take over to maintain system operation.
2Reliability
If duplicative resolver-RDC-converter controller combinations are used to provide redundancy, then system reliability improves, but the overall system cost significantly increases
Solution Approach 1:
Each converter controller is designed to perform multiple functions: it controls its associated power converter, processes resolver signals through its RDC, and simultaneously serves as a backup for other controllers through the shared communication network. This multi-functionality reduces the need for dedicated redundant components.
Solution Approach 2:
The system implements self-diagnosis and automatic failover capabilities where controllers monitor each other's status through communication buses and automatically take over control functions when a failure is detected, eliminating the need for external intervention or complex manual redundancy management.
3Reliability
If each converter controller has its own independent RDC connected to its own resolver, then each controller can independently determine shaft information, but the system lacks redundancy and any failure renders the whole system inoperable
Solution Approach 1:
Communication buses serve as intermediaries that connect all converter controllers and enable them to share shaft information. Instead of direct point-to-point connections between all controllers, the communication bus acts as a mediator that facilitates information exchange and coordination throughout the system.
Solution Approach 2:
The system implements feedback mechanisms where controllers continuously monitor the status of other controllers and resolvers through communication buses. This feedback enables automatic detection of failures and triggers appropriate failover actions to maintain system operation.
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 solution provides redundant shaft information, ensuring system reliability and reducing costs by enabling continued operation with failed RDCs, as each converter controller can use redundant digital shaft information from other resolvers, thus maintaining power converter control.
Implementation Method 1
resolvers require an alternating current (AC) excitation signal and analog output signal processing circuit to determine the shaft angle and speed
Data Source
AI summary
Electric machine drive systems, and related electric machine embodiments, include technologies for providing redundancy of shaft information of one or more electric machines between converter controllers of the corresponding system. The converter controllers are configured to control operation of power converters, which control one or more electric machines. The disclosed technologies include establishing one or more communication buses between the converter controllers to share the shaft information, which may be based on analog signals from a single, common resolver and/or from different, redundant resolvers depending on the embodiment. For example, in some embodiments, converter controllers communicatively connected to the same resolver may include separate resolver-to-digital converters (RDCs) to provide redundancy of the RDCs.