An active temperature control device for fuel cell stacks based on a compound pid controller

Abstract

An active temperature control device for fuel cell stacks based on a composite PID controller provided by the present invention includes a double-sided monitoring device, a CPU, an analog-to-digital conversion module, a power module, a controller, and a host computer; the double-sided monitoring device is set at any Between two adjacent fuel cell units, it is composed of multiple monitoring units, and the monitoring units are respectively buried with wire resistance, sampling resistance and heating resistance; when the deviation between the preset temperature and the temperature signal is greater than the deviation threshold, the controller according to the traditional The preset coefficient in the PID algorithm controls the resistance value of the corresponding adjustable resistor in the power module; when the deviation is less than or equal to the deviation threshold, the controller adopts the fuzzy PID algorithm, according to the deviation and the deviation change rate in the fuzzy control rule table proposed by the present invention Query each coefficient to obtain the output to control the resistance value of the corresponding adjustable resistor, and then change the partial pressure on the corresponding heating resistor to realize zone heating. It has the advantages of good adaptability, high control precision, and fast heating speed.

Description

technical field [0001] The invention belongs to the field of fuel cells, in particular to an active temperature control device for fuel cell stacks based on a composite PID controller. Background technique [0002] Proton exchange membrane fuel cells (PEMFCs) are widely used in automobiles, unmanned aerial vehicles, and stationary power generation systems due to their low pollution, low noise, high power density, and high energy conversion efficiency. However, the life attenuation and stability of fuel cell stacks limit the large-scale commercial application of fuel cells. The performance is affected by many factors, such as stack temperature, humidity, flow field shape, etc., which directly affect the temperature and current density distribution. The temperature of the fuel cell is related to the moisture content in the ionomer of the proton exchange membrane and the catalyst layer, thereby affecting the performance of the fuel cell. Therefore, it is of great significance ...

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Problems solved by technology

However, there is a dead zone setting problem to control the temperature by adjusting the on-off time, and there will be hysteresis. For example, when the set temperature gap is 2°C, the conductor will cut off the voltage when the temperature changes from 60°C to 62°C, which makes Temperature adjustment is a control system with a large lag, because it takes a while to heat up after power on, and even the temperature will drop when the power is just turned on, and the temperature will not drop immediately after the power is turned off at high temperature, so it is controlled by adjusting the on-off time The temperature method has the disadvantages of low accuracy and large temperature hysteresis

In addition, the control parameters of the traditional PID control algorithm cannot be adjusted online, and there are phenomena of overshoot and hysteresis in the temperature; fuzzy PID control is an intelligent control based on language rules, which does not depend on the accurate model of the controlled object, and has a simple structure and adaptability Good, robust and other advantages, in recent years have been applied to the fuel cell temperature control system, the existing fuzzy temperature control still has some shortcomings, such as when the error between the set temperature and the actual temperature e (k) = Tref When (k)-T(k) is large, the adjustment time is long and the accuracy is poor

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