Research And Design For Hybrid Reactive Power Compensator Based On DSP

With the development of science and technology, a large amount of electrical equipment brings convenience to people's production and life. As a consequence,a great amount of reactive power appears. In the new century, as the use of power electronic devices in the electricity system increases greatly, the demand for power quality is also getting higher and higher. The existence of reactive power results in the stability of voltage and the power factor of grid reducing, which seriously affects people's daily production activities, thus there is of great significance for the compensation of reactive power to improve the quality of electricity. On the other hand, the reduction of reactive power corresponds to the decline of electricity consumption. Therefore, whether from the perspective of economy or green environmental protection, it has a positive meaning to reduce the current going through the electrical equipment.As a large capacity, low cost, economic compensation, the main drawback of TSC (thyristor switching capacitor) is that it can only absorb inductive reactive power,and on the other hand, it can't do the fine compensation, because the minimum margin of compensation is affected by the size of the capacitor. STATCOM (static synchronous compensator) reacts fast, and it can realize the continuous compensation for reactive power as well as make compensation for the capacitive, inductive reactive power. However, its control is complex and the cost of large capacity STATCOM equipment manufacturing remains high. Based on this, this paper combines the advantages of two kinds of equipment, and puts forward the design scheme of hybrid reactive power compensation of STATCOM+TSC. On the basis of in-depth analysis of the basic principles of STATCOM and TSC, this paper makes an appropriate selection of the design. As for the testing of reactive current, this paper makes a comparison among Fourier reactive power algorithm, reactive power algorithm and reactive power algorithm, and chooses an appropriate reactive power algorithm according to the design by analyzing their characteristics. As for the modeling analysis of the STATCOM, the overall control of the hybrid system is theoretically analyzed under the appropriate current control algorithm. In order to verify the reliability of the theory, a simulation system is built with Simulink to verify the rationality and feasibility of the design.For the study on the core DSP of the system, this paper designs the matching sampling circuit and conditioning circuit based on the DSP, gives the design process of the program, complies the suitable program for the design under the matching software, and continuously tests as well as improves program by the emulator. Taking DSP as the core control of the hybrid systems, combined with the design of hardware and software, this paper sets up three groups of devices with STATCOM as the compensation capacity and TSC as the compensation capacity. After the grid connected experiment, it is proved that the system can meet the requirements in the aspect of real-time compensation for reactive power, dynamic response and compensation effect meeting the design under the experimental environment.