A cement company is a large regional cement production enterprise. The kiln head power room is the core power supply hub for clinker burning, which provides low voltage power supply for large equipment.
1. Introduction to the Project
A cement company is a large regional cement production enterprise. The kiln head power room is the core power supply hub for clinker burning, which provides low voltage power supply for large equipment. The system inductive load accounts for over 80%. The original LV capacitor reactance compensation mode had the problems of low compensation accuracy and slow response speed. The power factor of the power grid was only 0.8, which failed to meet the industrial power standard; The harmonic current generated by the production equipment made the distortion rate of the power grid exceed the standard, the utilization rate of the power equipment was low, the invalid power consumption cost was increased, and frequent failures and voltage fluctuations affected the stability of the production, with potential safety and efficiency hazards. And the original compensation cabinet body space was fixed, so the conventional expansion and transformation scheme cannot be implemented. Silicon carbide active filter APF+SVG compensation integration scheme is adopted to complete capacity expansion and active filter configuration without adding new cabinet, create low voltage power quality control and reactive compensation system suitable for kiln head working condition and solve enterprise problems.
2. Project Key Challenges
Due to the particularity of cement kiln head production and difficulties in site transformation, the Project faces three major problems:
1) The power factor of the original compensation cabinet failed to reach 0.90 for a long time, resulting in a fine of tens of thousands of USD per month; The cabinet space was fixed without extra space. It was required to complete 300kvar compensation capacity expansion and 500A active filter configuration in limited space, so the space utilization was difficult.
2) Due to high dust concentration and large equipment vibration at the production site of kiln head, silicon carbide power electronic equipment could be easily affected by dust intrusion and vibration.
3) Cement production is a continuous operation, the kiln head has no long-term shutdown conditions, the reconstruction construction and commissioning time was limited, and the low voltage power distribution core system is involved. Improper operation was easy to cause power supply interruption, and the risk is high.
3. Main measures and solutions:
1) The APF and SVG compensation device based on silicon carbide power device are selected. The devices have the advantages of high frequency and in small sizes. Compared with the traditional silicon based equipment, the volume of the device is reduced by 65%. The device can be directly embedded into the idle position of the original compensation cabinet without changing the cabinet body and power distribution layout; We completed the simulation installation of equipment with CAD 3D modeling, accurately plan the equipment placement, wiring direction and heat dissipation space, ensure that the original power distribution system will not be affected after the equipment is installed, and maximize the use of limited space.
2) During the implementation of this project, independent air duct is applied to our filter module, and each circuit mainboard is filled with glue (dustproof, waterproof and moisture-proof) to avoid short circuit caused by dust falling on the circuit board, and the overall installation and commissioning cycle is shortened from 10 days to 5 days, without slowing down the normal production of the kiln head in the whole process.
4. Project implementation effects and benefits
Through 6 months of continuous operation monitoring, all technical indicators of the Project have exceeded the expectation and achieved remarkable results in technical and economic aspects. Meanwhile, the Project has been highly recognized by the Owner. The power factor of the low voltage power grid of the kiln head power room is increased from 0.8 to 0.96 after reconstruction and is stable for a long time, reaching the high quality standard of industrial electricity; The voltage and current distortion rate of the power grid shall be reduced to within the requirements of the national standard, so as to completely solve the problem of substandard power quality; The utilization rate of power supply equipment is improved, the hidden dangers such as switching failure of compensation equipment and grid voltage fluctuation are eliminated, the continuous and reliable operation of core production equipment of kiln head is guaranteed, and the contribution to high-efficiency cement production of enterprises is made.
In terms of feedback from the Owner, the cement company highly affirmed the implementation effect of the project, and thought that the project completely solved the industry difficulties of low power factor and unqualified electric energy quality in the kiln head power room for a long time under the premise of no new cabinet and no impact on normal production.