Week 7 State of charge estimation

CHALLENGE WEEK 7 STATE OF CHARGE ESTIMATION 1.Simulate the 3 test cases from harness dashboard and write a detailed report on the results. Test Case 1: Normal Driving, Charging, and Standby mode. In this test, I looked at the behavior of the Battery Management System (BMS) throughout various tasks. The BMS operated without a hitch. This is what happened: After 3000 seconds, the car started moving and then changed to charging. It entered standby mode after the charging process had reached 90%. While charging and driving, the battery warmed up a little. The battery voltage hit 4.2V while it was charging. While driving, I could see how much power was entering and leaving the battery. While driving, the battery's State of Charge (SOC) dropped below 50% but rose during charging. Test case 2: After the test case variant changed to 2. I attempted charging in the second test, but something went wrong. Here's what I noticed: There was a difficulty when I attempted to charge the battery. Instead of increasing as it was supposed to, the SOC remained decreasing. Test case 3: Changing test case variant to 3 In the third test, I concentrated on what occurs when we continue to charge while moving or halting. Here are what I have found: I did not use the battery while driving or in standby mode; I just continually charged it. During charging, the SOC reached 100% and remained there. As soon as the battery entered standby mode, its temperature dropped. Therefore, if we continuously charge without pausing, the battery finally reaches 100% and remains intact. In conclusion, these experiments gave us a better understanding of how the BMS functions under various conditions. In Test Case 1, everything was shown to be operating correctly; in Test Case 2, a charging issue was highlighted; and in Test Case 3, it was shown how the battery maintains a 100% charge while it is regularly charged. These tests assist us in evaluating the BMS functionality and identifying any problems with how it controls the battery. 2.What is coulomb counting? Refer to the above model and explain how BMS implements coulomb counting for SOC estimation? A commonly used method for determining a battery's State of Charge (SOC) is coulomb counting. It makes use of continuous electrical charge flow measurements into or out of the battery. Coulomb counting is used in the Battery Management System (BMS) model that you specified in the following ways: Inputs: The BMS system receives inputs like temperature and battery current. Integration: Over time, the current entering or leaving the battery is incorporated. The cumulative charge that has entered or left the battery is represented by this integration. SOC Calculation: The nominal capacity of the battery and integrated charge are used to determine the SOC. Coulomb counting is the method for estimating SOC, and the formula is: SOC(t) = Q / Q_nominal + SOC(t-1) Where: The SOC at time t is known as SOC(t). The SOC from the prior time step is SOC(t-1). Q is the integrated charge across the time step (current integration). The battery's nominal capacity is Q_nominal. The Coulomb counting block is located inside the SOC estimate block of the BMS model. The actions taken by this block are as follows: Current measurement: Measures the amount of current entering or leaving the battery. Temperature Compensation: The BMS takes this into account by modifying capacity dependent on temperature. Temperature information may have an impact on battery capacity. Integration: The time component of the current signal is integrated. Division: To calculate the SOC, divide the integrated current by the battery's nominal capacity. In summary, to calculate SOC by monitoring the passage of electrical charge into and out of the battery over time, Coulomb counting is included in the BMS model. The approach is simple and effective in terms of computing, with temperature correction being one of the factors for accuracy in the SOC estimating process.