Power quality is an important index of power industry products, which involves the rights and interests of generation, supply and use. With the progress and development of science and technology, there are more and more impact and nonlinear loads, especially the application of power electronic devices, which makes the power quality problems such as harmonics, voltage fluctuation, flicker and three-phase imbalance particularly serious.
The power quality problem of the automobile industry is mainly reflected in the automobile manufacturing industry, while in the automobile manufacturing industry, it is mainly reflected in the production process of stamping, welding, painting and final assembly. The whole automobile manufacturing process is closely connected, has the characteristics of high integration, and has relatively high requirements for power quality. The power supply failure and electrical accident of any manufacturing process will affect the normal operation of the previous process or the next process. Therefore, harmonic control is of great significance to the automobile manufacturing industry.
Power quality issues:
The main load of the coating process is power electronic devices and large-capacity heating equipment, which are manufactured by the principle of rectifier and frequency conversion, which will produce harmonics in this process, while the heating equipment uses devices with high resistance. The power quality of the painting workshop is characterized by large inductive reactive power, low overall power factor, large and complex harmonic current, serious reduction of system bus voltage, high calorific value of equipment and low utilization rate.
Harmonics will increase the equipment loss of the painting workshop, increase the iron loss, copper loss, dielectric loss and peak voltage of the main transformer, increase the noise of the transformer and reduce the load capacity of the transformer. Harmonics will cause misoperation of painting, painting, transportation and other equipment, resulting in uneven painting, transportation is not in place, bubbles, leakage, grinding is not in place, repeated painting and other defects appear on the painting surface, which seriously affect the painting quality of the products.
Due to the increase of system reactive power consumption, the decrease of bus voltage and the deviation of voltage, the heating equipment will not reach the temperature standard of baking automobile surface coating within the specified time because the voltage is too low, resulting in baking quality problems.
Power quality governance:
The passive filter device is used to filter out the characteristic harmonics of the system and compensate the reactive power at the same time. The switching switch adopts thyristor switch to meet the requirements of rapid load change. The dynamic safety compensation device MVTS adopts the mixed compensation mode of three-phase co-compensation and sub-compensation, which meets the compensation requirements of the three-phase imbalance of the system.
Through the mixed use of active power filter and dynamic safety compensation device, it can solve the harmonic influence of the power distribution system in the automobile manufacturing industry, reduce the system loss, and make the distribution system operate safely and efficiently. In particular, it is of great significance to the users who have high requirements for power safety.
The dynamic reactive power generator is used to provide reactive power to each phase of the system, and each harmonic of the system is controlled at the same time.