Research And Implementation Of The Energy Feedback Type Electronic Load

The testing of various types of power needs the participation of the load, but the traditional static load will consume large amounts of energy in the testing. However, the electronic load has controllable characteristic, at the same time, energy feedback electronic load can urge the energy of the measured power feedback to the grid, reaching the purpose of saving energy. This paper will take systematic academic research, simulate and do some experiment for the current tracking strategy and the implementation of the electronic load.Firstly, the paper selects the BOOST circuit as the topology of the forward converter circuit after comparing. Based on this topology, simulate and analyze the static and dynamic response of the DC electronic load in constant current and constant impedance modes. And establish the AC electronic load modeling which is based on the PWM rectifier, analyze the static and dynamic response in two modes above. Choosing PI controller as the input current control strategy, accordingly making the electronic load can track the changes of the input current quickly, so that the input current can real-time and accurate tracking the current reference value, making sure the electronic load can be stabilized to work.Secondly, this paper analyzes the operation of electronic load through the view of energy balance. By setting up the mathematical model, this article calculates the result that input power and output power can reach a balance when the voltage among the DC bus capacitor can maintain stability. By analyzing the DC bus voltage fluctuation, and calculating the maximum amplitude of permitted fluctuation, this paper analyzes the conditions that the input power and bus capacitance required to meet in qualitative way, while the electronic load ensure output power continuously in a dynamic situation.This paper studies and analyzes the grid-connected inverter current control strategy. Combined with grid voltage feed-forward control and zero-error current tracking control technology, this paper presents a new current control strategy, which can compensate for grid voltage disturbance on the system error and sinusoidal current on the system caused a given error as well, so that inverter output current can be error-free tracking the grid voltage, and fulfill grid-connected with high power factor. Then, establishing the circuit modeling and simulating, through comparing grid-connected current waveform generated with other control strategies, verify the feasibility of the theory.Finally, this paper introduces hardware design and software design, the circuit parameters and the choice of components in hardware circuit design, and software program flow chart of the circuit. Through the experimental implement some of the functions of DC electronic load, and record the experimental data and experimental waveforms, summarize the debug work.