Band-pass Regulator And Being Used In Inverter Control Of Energy Feedback Electronic Load

In recent years, many kinds of power electronic equipments and chemical batterys wereused widely, such as uninterruptible power supply (UPS), active power filter (APF), static varcompensator, lead battery and lithium battery, etc. They must be testing before they leave thefactory. The shortcomings of the traditional static load:①Lack of flexibility, they can’tsimulate constant voltage、 Constant current、 constant power and other special load;②Thewaste of energy, they are not suitable for high power test.Electronic load overcome the shortcomings of the traditional load. It is the combinationof Power electronic technology, Computer control technology and Automation technology.Energy feedback type electronic load not only has the strong flexibility and can simulate allkinds of load; but also will make absorbed energy no pollution feedback network. Thereforethe market prospect is very broad.First is elaborated Energy feedback type electronic load implementation scheme. MakingAC/DC、DC/AC double PWM as the main circuit topology. Analysised the principle ofsimulate arbitrary load in the PWM rectifier, the principle of the unit power factor energyfeedback and stable DC bus voltage in PWM inverter.Stable DC bus voltage and current tracking control use Voltage-Current double closedloop control scheme. According to the problem of the DC bus voltage ripple caused currentdistortion, puts forward a new Band-Pass (BP) regulator, used this regulator in Inverter-Gridsystem, effective suppression of the Inverter-Grid current harmonic.According to the characteristics of BP regulator and designed the current loop system,and compared with PI and PR regulator system. The most obvious characteristic of the BPregulator system is the Band-Pass. This characteristic makes the system only respondfundamental frequency, harmonic all suppression outside of fundamental wave; the systemband of the BP regulator is very narrow, can alleviate the actual system band nervous.The closed-loop system used the BP regulator for also has some disadvantages. The mostobvious shortage is can not adjustment the interference of forward channel, so the system hasGrid-Voltage feedforward and DC bus voltage feedforward. Secondly, the current loop bandis very narrow, leading to the slow response; through designing the voltage loop reasonabled,can improve the current loop response slow, at the same time also can ensure the fast andaccurate of voltage loop. Finally, the system using the BP regulator phase track is sensitive tothe frequency, the real-time correction system resonance frequency is equal to the power gridvoltage frequency to ensure phase tracking accuracy.Finally this paper was presented the results of closed loop system simulation andexperimental using BP controller and PI regulator. The simulation and experiment have shown that the BP regulator proposed and the closed loop system validity and feasibility.