The Design Of High Power High Voltage Frequency Converter And Its Application

At present, China’s industrial electricity is a major component of social power.High-voltage motors in domestic wide range of applications, main drag fans, pumps, compressors and other large machinery. They are the main driving force of the industrial and mining enterprises. At this stage of the motor system low efficiency, high energy consumption, resulting in equipment for a long run in the low load condition, the motor system energy imperative. VVVF motor at this stage is the most effective energy-saving equipment. Corresponding in this way to derive several types of high-voltage inverter, such as a current source, the three-level PWM voltage source type, unit multi-level PWM voltage source type inverter series.Multi-level PWM voltage source inverter unit in series with its easy to implement, a wide range of applications, low cost, easy to transform as well as ease of service and other advantages to become the mainstream of the domestic market, high-voltage inverter industry. The article describes a high voltage inverter system structure based on the frequency converter of this type, and elaborate on the implementation of control cabinet, power cabinet and transformer cabinets and other cabinets. The transformer cabinet introduces the principles and parameters of phase-shifting transformer selected; Power cabinet to focus on the power unit describes the realization of the main circuit of the unit, and focuses on the bridge rectifier,IGBT, the original parameters of the electrolytic capacitor and select; Control cabinet as the inverter control system, on the one hand, PC monitoring, real-time transmission of the data; the other hand, is responsible for the lower machine control logic and data transmission, to ensure that the system is safe and reliable operation. Therefore, the control system on the one hand described control unit up and some of the features, on the other hand tells the PLC electrical control equipment and to communicate with the host computer or remote terminal.The high-voltage inverter control strategy v/f control strategy widely used in fans, pumps and other load types. Its advantage is the output waveform can be improved significantly, reducing the harmonic losses of the motor and reduce the torque ripple and to simplify the structure of the inverter, speed regulator. The application of the transform technique of the modulation wave can change the size of the circuit output voltage and output frequency, to improve the voltage utilization factor at the same time reduce the number of switching times. Phase shift carrier PWM modulation technique SPWM and a phase-shifted carrier combined, so that the amplitude of the pulse of the PWM increases but the level number and the equivalent switching frequency does not increase and the du/dt is a good PWM modulationway. Last eight H-bridge power unit series of simulation using MATLAB simulation software.Automated high-voltage inverter Experiment Station laboratory equipment, experimental steps1000kVA/10kV high voltage inverter completed device20Hz,30Hz, and50Hz, load test, and record the voltage waveform and the experimental data, while in the experimental stage,issued simulation waveforms in the frequency and compared.Based VVVF energy saving principle and fan running performance, high-voltage inverter applications in the industrial dust blower and induced draft fan, for example, inverter applications do feasibility analysis according to the actual operating data to calculate the electricity savings, remarkable energy savings achieved their intended purpose.