Can be soft-configured fuel cell engine control system
Proton exchange membrane fuel cell (Proton Exchange Membrane Fuel Cell, PEMFC short) is a stored in the fuel and oxidizer in the chemical energy into electrical energy generating device, with high energy, noise, pollution, zero emissions and energy conversion High efficiency, especially suitable for electric vehicle power and energy. Governments, enterprises and research institutions dedicated to research focused on proton exchange membrane fuel cell electric vehicles, fuel cell engine fuel cell electric vehicles as the core of new breakthroughs is currently in pre-, is becoming the new hot topics. At present, many studies of fuel cell engines are simply dedicated to improving the performance of the fuel cell stack, the control system is relatively small, while the fuel cell engine is good or bad in addition to the stack itself Characteristics of a large part outside the control system also depends on the degree of good or bad. the traditional control system is based on the specific characteristics of the engine design, and a fixed control strategy, the line interface and operating parameters to a large extent limited the control functions Extension of the control system can not meet the user's use and development needs, but also in the maintenance of the system software was modified and degraded by constant. In view of this, the paper proposed and designed a new type of fuel cell engine can be soft-configured control system In meeting all control objectives but also the ability to upgrade the software configuration, a variety of optional features such as control strategy, which greatly improves the flexibility and adaptability of the control system, and achieved good control effect.
1 can be soft-configured fuel cell engine control system structure
Can be soft-configured fuel cell engine control system structure according to their functions by the following new components: the host computer configuration terminal, can be soft-configured controller, the fuel cell stack, hydrogen supply system, air supply system, humidification system, cooling water management systems, security alarm system, communication control system, shown in Figure 1. Fuel cell engine configuration than the crew as a soft end to the controller for the control and coordination center to the fuel cell stack is the core of the engine into the stack of hydrogen and oxygen in the reaction under certain conditions, to produce electricity and water. PC configuration terminal can select different control strategies can also configure the controller software upgrade. Hydrogen supply system is responsible for the stack to provide a certain pressure and flow of pure hydrogen. Stack air supply system to provide sufficient air for the reaction. Humidification system is responsible for the stack to facilitate the provision of appropriate humidity increase the reaction efficiency. Cooling water management system is mainly issued to stack the excess heat through the circulation of deionized water to bring out the stack and through the cooler heat, so that the stack is efficient reaction conditions. Security alarm system work through real-time detection of the stack during the various states and parameters, the fault alarm information appears in a timely manner. Real-time communications monitoring system displays the current status of various physical data and run, and record the required data for analysis.
2 soft-upgrade mechanism configuration
Can be soft-configured fuel cell engine control system is a characteristic of the soft configuration can be upgraded. Statistics show that the control system has been the improvement of survival and adaptability of its maintenance work 70% of the workload. Passively to maintain and modify the demand changes occur in the life period and then re-programmed the control system or even design the controller, the cost is expensive. Can be soft-configured fuel cell engine control system is an internal structure can be reconfigured, the control parameters can be continuously adjusted to meet the hardware environment, the control parameters change control system, its configuration can be divided into the controller upgrade feature to upgrade the port configuration and parameters configuration upgrades.
2.1 Software configuration controller can be
Controller is designed to fully take into account various factors that may change, retaining only the main framework for the main program, all variable information is stored separately in a special module, configure the terminal is responsible for selecting the host computer system is running the strategy and will kinds of software configuration upgrade information to the controller, once the system need to configure the update, users do not understand the control procedures in the case of simple operation, greatly reducing the development cycle of the controller improves the system's suitability and operational sex.
Shown in Figure 2, the controller hardware consists of a microprocessor (DSP), the watchdog module, power control module, the software configuration module, signal conditioning and analog-digital conversion module, digital to analog conversion circuit, I / 0 module , SCI, and CAN communication module and other components. PC terminal using VB software configuration design, integration of the upgraded configuration system and the data monitoring system, can upgrade the software configuration can also be real-time display and record data, and used between the DSP 485. EEPROM software configuration modules to receive and store the configuration information from the host computer, through the SPI to communicate with the DSP. Controller through the interface to a variety of external analog signals and digital signals, analog signals, including voltage, current, pressure, flow, temperature, humidity, digital signal includes a variety of solenoid valves and relays. The controller implements the control system's modular design and miniaturization, high flexibility, high reliability, high anti-interference, high-speed signal processing capabilities as well as advanced software configuration upgrades.
2.2 Upgrading the controller port configuration
Controller to set a lot of the hardware control port, for example, analog to digital converter module connected to the various sampling ports AD, DA digital to analog converter module ports simultaneously control several fans, I / 0 module I / 0 port control opening and closing of the relay, and alarm information to receive hydrogen gas, which is connected to the controller hardware port is configured for the soft upgrade. When the fuel cell engine control system, subsystem, or stack testing rectification, some of the lines connecting the controller ports are bound to change, then, through the PC can easily configure the terminal to adjust the controller's internal interface set the controller to quickly adapt to new hardware requirements.
Shown in Figure 3, AD sampling is the main input channel signal, the signal acquisition, such as hydrogen pressure and out of the heap, the stack voltage and current, air current, and out of stack temperature, cooling water and the humidification level of water flow; I / O ports mainly refers to the DSP's digital inputs and outputs, then the relay output control by controlling the various solenoid valves, pumps, motors, switches, load switches, such as charge, hydrogen nitrogen tail valve, humidifier water pumps and hydrogen circulation pump, etc.; I / O inputs include the number of hydrogen alarm switch signal; digital to analog conversion module will output the digital DSP into analog control fans, each DA control of a fan, the size of output determines the fan speed speed. When the hardware port the stack shift, circuit restructuring and other changes, through the PC terminal port to reconfigure the control system can be programmed in the case of free and new hardware required to maintain sync.
2.3 Parameter Configuration Upgrade
Fuel cell engine control system commonly used parameters include the various control parameters, security parameters and various sensor calibration parameters. Among them, the control parameters, including flow control switch, fan power control, humidification water flow control, emissions control; security parameters, including various types of alarm parameters, stack protection parameters (since shut down, load shedding), the protection time delay parameters ; various types of sensors such as voltage, current, water level, pressure and other sensors. Sensor is an important channel AD sampling, the controller integrates a variety of sensors on the calculation of transformation parameters initial sampling, the parameter contains the sensor range, signal type, etc., but when the sensor is damaged, replacement, etc., the controller The calculation parameters need be adjusted accordingly. Experimental results show that reasonable parameters can be configured to various types of restructuring the entire control system in time control strategy can be more secure, reliable, fuel-cell engines to achieve the optimal net power output.
For example, since the shutdown conditions, the stack temperature, hydrogen pressure, air currents are all important factors affecting the normal work, once out of range in the control system will execute commands from the shutdown, when the stack performance upgrades, the power heap can bear the corresponding augmented the scope of work, then configure a new PC can be shut down conditions for self-configuration controller are upgraded accordingly.
Implementation Strategy 2.4 upgrade software configuration
PC configuration information to the controller, the controller will determine the identification and classification of information stored in the soft partition configuration EEPROM module, and then the main program by the DSP has been sorted from the EEPROM to call a fixed address. PC upgrade information in the configuration is equivalent to changing the data stored in the EEPROM in the order or size, the system uses the EEPROM space the size of 64Kb, each page data store 32 bytes (0x0000-0x0031), can be storage 256 (0x0000-0xFF00), each page can store a configuration information.
(1) mapping to model
The configuration of the controller ports during the upgrade, the PC terminal and controller configuration software configuration module defines each hardware port form a collaborative mapping model. The so-called mapping model can be abstracted into a function like map, where and are two component sets, where the controller can be expressed as the actual hardware port number and applications, is to a map, is variable xyfxyf: x → y, and the mapping to be through the medium of performance EEPROM and save. Each host computer sends a new port configuration, change once the new hardware port functions accordingly. For example, the original controller interface to the initial first way AD is set to "capture into the stack temperature signal", the second way AD is set to "capture the stack temperature signal", where the "first road" and the "second way" is mapping model, that this is a hardware port on the controller serial number; and "into the stack temperature" and "out of stack temperature" is the host computer to be configured to indicate the practical application of the port function; and put both associate, expressed to the mapping. When the host computer to configure the two way exchange of AD when the interface is also changed accordingly, the configuration of the result is the "first road" AD port into a "capture the stack temperature signal", the "second way" AD port will be turned into "Collection into the stack temperature signal ".
(2) The Executive cited Zhi
PC configuration of the controller to complete the work, in the soft configuration of each module will update the appropriate information to establish the mapping model is completed, then, DSP and then through the implementation of the various mapping models cited Zhi call to the main program module corresponding in. Execution engine is a configuration than the mapping model that higher-level mapping model, the same token it can also be abstracted into a function mapping, where is the upgrade of software configuration information mapping module in the model, such as the AD port mapping model, I / O port mapping model, mapping model from the shutdown conditions, such as sensor calibration mapping model; and is the main program to upgrade the information to perform this part of the program modules, complete the mapping model to the corresponding program execution module of the mapping.
Coordinated control strategy performance over three
Can be soft-configured fuel cell engine control system is another special control strategy lies in its diversity. Traditional control system for individual control of only one object in terms of the general control strategy, in the control process can not meet the needs of users or extensions, sometimes in order to meet the different control objectives have to re-program the program or re-design the controller. As shown, the system controller through the PC soft-switching strategy in the integrated database, you can easily use a variety of different control strategies to control the fuel cell engine. Alternative control strategies in a systematic control strategy for the global coordination of the normal operation of the system normal operation of the local coordinate system of partial failure of the control strategies and coordinated control strategy operation. A variety of alternative control strategies to a large extent in the control system to meet the different needs, and easy to operate, the friendly man-machine dialogue.
Based on the configuration of fuel cell engine can be soft-upgrade feature configuration requirements, design, software configuration that can be configured to upgrade the controller and the corresponding mechanism, the controller realized the internal port structure and control system operating parameters can be soft-configured upgrade. The paper also raises fuel cell performance of the engine control system and more coordinated control strategy and its control system in the application of a preliminary exploration. Practice shows that the control system runs stable, reliable, and get a good control effect. The author Innovations:
1, the design of fuel cell that can be soft-configured mapping of the engine control system model and pull out the implementation of guidelines
2, the control system with flexible configuration capabilities
3, the design of a multi-performance coordinated control strategy to achieve coordinated control of multiple performance
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