# Energy-Feedback Load Simulation Algorithm Based on Fuzzy Control
## 6 Load Simulation Strategy Based on Fuzzy Control Variable Load Simulink Simulation Results  
The energy-feedback DC electronic load studied in this paper has four load simulation modes of constant current, constant resistance, constant power, and variable load. The following four load simulation modes are used for functional tests in turn. An oscilloscope is used to measure and record the waveform of the input voltage \(V_{\text{IN}}\) and input current \(I_{\text{IN}}\). In the constant current load simulation mode, the input current setting value \(I_{\text{SET}}\) is constant at 5.0 A, and the input voltage \(V_{\text{IN}}\) gradually and steadily increases from 200 V to 300 V. The simulation function test results of the constant current load are shown in Figure 11a. When the input voltage \(V_{\text{IN}}\) changes, the input current \(I_{\text{IN}}\) remains constant, and its effective value is 4.90 A; thus the simulation function of constant current load is normal. The constant resistance load simulation mode of input resistance value \(R_{\text{SET}}\) constant is 50 \(\Omega\). The function test result is as shown in Figure 11b. With the increase in the input voltage \(V_{\text{IN}}\), input current \(I_{\text{IN}}\) increases proportionally, and thus the equivalent resistance \(R_{\text{IN}}\) constant is equal to 50.4 \(\Omega\), and the test results show that the proposed load simulation control strategy based on analog control has good dynamic performance. The input power of the constant power load simulation mode setting \(P_{\text{SET}}\) constant is 1000 W. The test results are as shown in Figure 11c. With the increase in the input voltage \(V_{\text{IN}}\), input current \(I_{\text{IN}}\) decreases inversely proportionally, and the change in input current is smooth, does not trigger any system protection action by accident, and in the entire process of the constant power test, the input power \(P_{\text{IN}}\) constant is equal to 1006 W. The test results show that the simulation function of constant power load is normal and the dynamic performance of the system is good. The initial set value of input current in the simulation test of variable load is 2.0 A. During the process of the variable load test, the set value of input current is changed from 2 A to 4 A, then to 6 A after 4 s, and finally to 8 A after 4 s. The test results show that the input current \(I_{\text{IN}}\) changes from 2 A to 4 A, 6 A, and 8 A successively. The simulation function of the variable load is normal, and multi-stage programming output can be achieved. The dynamic response of the input current tracking is rapid, and the current flow is small in the response process. The initial set value of input current \(I_{\text{SET}}\) in the simulation test of variable load is 2.0 A. During the process of the variable load test, the set value of input current \(I_{\text{SET}}\) is changed from 2 A to 4 A, then to 6 A after 4 s, and finally to 8 A after 4 s.  
The test results show that the input current \(I_{\text{IN}}\) changes from 2 A to 4 A, 6 A, and 8 A successively. The simulation function of the variable load is normal, and multi-stage programming output can be achieved. The dynamic response of the input current tracking is rapid, and the current flow is small in the response process. Figure 13: Load simulation power relative error curve. and the input-current-tracking error and constant power load simulation precision are also reduced. The range of constant resistance load simulation is 15-400 \(\Omega\). In the constant resistance load simulation accuracy testing process, the input resistance value is set to 20-200 \(\Omega\) with a total of 10 different values of resistance. Respectively, we measure and record the input voltage and input current and then calculate the equivalent input resistance.