Alstom Generates Production Code for Safety-Critical Power Converter Control Systems

Alstom engineers needed to design energy management controls and power converter controls that meet stringent performance requirements with sub-millisecond latencies.

"A latency of 10 to 20 microseconds is too much because our cycle times are about 200 microseconds," explains Geerligs. "We also have complex multiprocessor models that can have a DSP running an interrupt process and a Power-PC CPU using a multirate process."

Adding to the challenge, Alstom engineers used disparate tools for algorithm development, modeling, and simulation. Moreover, the tools did not provide any automatic code generation capabilities, so they had to write code by hand.

"Our tools were not integrated, so we spent a lot of time writing conversion tools. Since we had no way to automatically generate code, we would design, make specifications, and then hand code," Geerligs recalls. "It took a long time to go from specification to implementation. There was no rapid prototyping, documentation took longer, we lacked an overview of the entire effort, and it was very difficult to implement changes quickly."

After evaluating several commercial software packages, Alstom chose MathWorks tools for Model-Based Design. Alstom engineers used the tools to design, simulate, and automatically generate code on a number of projects, including a tramway control system and an energy management system for Czech Railways’ Pendolino tilting train.

在设计阶段，工程师使用Simulink万博1manbetx^®, Simscape Electrical™, and Stateflow^®to develop their control systems.

G万博1manbetxeerligs说：“ Simulink使得从设计的一部分转移功能或将时间从时机转换为中断驱动，同时保持效率。”“如果没有Simulink，这种主要的设计更改将非常困难。”万博1manbetx

工程师使用SIMSCAPE电气来对系统的电气组件进行建模，包括电源电子组件以及电阻器，电容器和电感器。

Using Stateflow, the team modeled the supervisory control and control system states, including start-up, slow-down, and error handling. The communication protocol between the power conversion control and the system’s central fault handling unit was also implemented in Stateflow.

Geerligs说：“状态流中的超级巨星对故障处理特别有用。当我们取代过故障时，我们从超级巨星中拔出了一条线，而状态流则确保了始终正确处理。”

The Alstom team used MATLAB^®to preprocess measurement data from fiberoptic interfaces and scopes for their simulations. They also used MATLAB to report and verify the simulation results. Geerligs used Control System Toolbox™ with MATLAB to create and analyze Bode diagrams and develop classical control algorithms.

在Simulink和stateFlow中模拟系统后，团队使用了万博1manbetxSimulink Coder™和嵌入式编码器^®to automatically generate production-ready code. They integrated the code with a number of real-time operating systems, including Microware 0S-9 and Wind River’s OSEKWorks.

阿尔斯通工程师他们的模型从项目中重用to project. "MathWorks tools helped us define design patterns and share that knowledge in libraries," explains Geerligs. "Fault handling and electrical modeling, for example, were shared between the tramway project and the energy management project."