How to build a super capacitor module assembly line?
As a new type of green energy storage element between capacitors and batteries, supercapacitors have the characteristics of long cycle life, fast charge and discharge performance and higher energy density. At the same time, it combines the high power characteristics of ordinary capacitors and the high energy characteristics of batteries.
As a new type of high-efficiency, green and intelligent rail transit vehicles, energy storage trams have the advantage of being based on super capacitors as the main power source to achieve 30 s rapid charge and discharge, long-distance continuous cruising, and large passenger capacity. With the vigorous development of the energy storage tram market, the traditional station system production model is far from being able to meet market demand. Based on the introduction of advanced process concepts, it has become necessary to build an assembly line that can achieve accurate detection of capacity and internal resistance, real-time monitoring of cell temperature rise, online determination of contact internal resistance, and integrated test of withstand voltage and insulation.
1. Overall plan
The super capacitor module assembly production line integrates module assembly, testing, storage, and other functions. By subdividing and adjusting each process, the rhythmic production is then realized. Line automation, tooling and equipment integration, and production rhythm control have become the salient features of the assembly line. A simulation diagram of the assembly line for the super capacitor module.
Among them, the assembly line automation requires that the assembly line can realize the functions of automatic product delivery, automatic performance detection, automatic storage and placement; tooling integration focuses on the reliability application of industrial loading plates and the integrated testing of test equipment tooling; production cycle Chemical control emphasizes that the assembly process of each process must be consistent with the line rhythm to achieve the smooth operation of the super capacitor module assembly. The specific operating mechanism is as follows.
The work loading board starts on the line from the first station and is transported to the end of the line body by a triple-speed chain, and the line is turned horizontally by a translation trolley; the front end of the loop walking line body is formed by another translation trolley to form a loop. Horizontal cycle.
In order to ensure the module gap accuracy requirements, the 180º automatic turning system is integrated in the third station of the assembly line to meet the process assembly requirements of the special turning assembly of supercapacitor modules.
Similarly, the fourth station highly integrates the functions of the withstand voltage meter test terminal and the module characteristic test bench test terminal into a set of 'test station unitSynchronous detection of charging and discharging; Based on the construction of the automatic storage unit, the fifth station speeds up the transformation of the super capacitor module from flat to three-dimensional storage and realizes the storage function of inputting the automatic storage module according to human instructions.
2. Comprehensive test system for super capacitor modules
As the core of the entire conversion production line, the integrated testing system for supercapacitor modules is responsible for the automated testing of key performance parameters such as module internal resistance, capacity, contact internal resistance, and temperature rise. Among them, the precise detection of the module's milliohm-level ultra-low internal resistance and ultra-large capacity is realized by relying on strict national technical standards and professional test equipment.
3. Principle of internal resistance test of super capacitor module
The super capacitor used in energy storage trams has the remarkable feature of ultra-low internal resistance. Based on the charge and discharge characteristics of the super capacitor, the internal resistance test method is as follows.
(1) Charge with a constant current to the rated voltage, and keep the rated voltage and constant voltage for continuous charging. Afterward, the switch S is switched to the constant current discharger and discharges with a constant current until it reaches 0 V.
(2) Use a recording voltmeter to record the voltage value between capacitor terminals that changes with time, and to obtain a straight line of the voltage between capacitor terminals that changes with time from the voltmeter Part of the extension, draw an auxiliary extension line.
(3) Obtain the voltage drop value ΔU3 from the intersection of this auxiliary line and the time coordinate when the discharge starts. Use equation (1) to calculate the internal resistance Rd.
In the formula, Rd represents the DC internal resistance, the unit is Ω; ΔU3 represents the voltage drop, the unit is V, and I is the discharge current, the unit is A.
4, the principle of super capacitor module capacity test
Charge with a constant current to the rated voltage, keep the rated voltage and constant voltage for continuous charging, then switch S to the constant current discharger, and discharge with a constant current to 80% of the rated voltage (U3) at the corresponding time t1, rated The time t2 corresponding to 50% of the voltage (U4). According to this cycle 3 times, calculate the electrostatic capacity of each cycle and take the average
The calculation of discharge capacity is shown in formula (2).
C putu003d[ I2×(t4-t3)]/( U3-U4) (2)
In the formula, U3 represents the starting voltage of the discharge capacity calculation, U4 represents the cut-off voltage of the discharge capacity calculation, I1 represents the charging current, and I2 represents the discharge current.
5. The realization of the test system
Based on the testing principle of super capacitor module capacity and internal resistance, the comprehensive test system of super capacitor module is mainly composed of testing tooling, pneumatic transmission system and testing equipment (including super capacitor tester, withstand voltage tester, temperature inspection instrument, Voltage rise and voltage drop acquisition unit) and other components, and its functions include testing the internal resistance, electrostatic capacity, withstand voltage, temperature, and contact resistance of the module.