SLAAEE3 july   2023 MSPM0L1306 , MSPM0L1306

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Gauge Hardware Introduction
  6. 3Gauge Software Introduction
    1. 3.1 Gauge Algorithm Introduction
    2. 3.2 Gauge GUI Introduction
  7. 4MSPM0 Gauge Evaluation Steps
    1. 4.1 Step1: Hardware Preparation
    2. 4.2 Step2: Get the Battery Model
    3. 4.3 Step3: Input the Customized Configuration
    4. 4.4 Step4: Evaluation
      1. 4.4.1 Detection Data Input Mode
      2. 4.4.2 Flash Data Input Mode
      3. 4.4.3 Communication Data Input Mode
  8. 5MSPM0 Gauge Solution Test Results
    1. 5.1 Performance Test
    2. 5.2 Current Consumption Test

3.1 Gauge Algorithm Introduction

For the VGauge, it treats the battery as a first order RC model. Then it will use the RC model and the SoC-open circuit voltage (OCV) table to generate VF_SoC. As it uses a low oder circuit model to simulate the battery, the accuracy of VF_SoC is not so high. However, it can help if you know the battery SoC when you do not detect the battery current or do not know the full capacity (AbsFullCap) at the beginning. In the software code, the RC model and SoC-OCV table are saved in “circuitParamsTable”.

GUID-E8DAC31F-B973-458E-8F9E-3A3E02D6CAAD-low.png Figure 3-2 Battery Model and SoC-OCV Table

Figure 3-3 shows the software flow chart of VGauge function. The circuitParamsTable (Rcell lookup table and SOC-OCV lookup table ) and Qmax are per saved. When the MCU start working, it treats the first AvgVcell as the OCV[K-1], then it looks into the SOC-OCV table to find the SoC. Rcell and Ccell are calculated and inputted in the model. With the AvgVcell input, a new OCV[K] is calculated, which is treated as a new OCV[K-1] inputted in the model in the next calculation cycle.

In a word, this model is used to evaluate the OCV based on the battery parameters and the AvgVcell input. The SoC is get by searching the SoC-OCV table.

GUID-05B5E127-B01F-4A43-A8F5-E2D8F92620C9-low.png Figure 3-3 VGauge Software Flow

For more details about VGauge, see Current sensor-less state-of-charge estimation algorithm for lithium-ion batteries utilizing filtered terminal voltage.