Summary:Local semiconductor material manufacturers are continuously enhancing their technological levels and R&D capabilities in semiconductor products, gradually breaking the monopoly of foreign semiconductor companies. This is advancing the domestication of China's semiconductor materials and promoting the development of the Chinese semiconductor industry. The manufacturing of semiconductor products, which utilizes equipment such as single crystal furnaces and multi-crystal furnaces, is a source of harmful harmonics. These harmonics generated by the equipment can pollute the power system and affect the quality of power supply. Therefore, electronic factories producing semiconductors require a comprehensive system solution to effectively address the power quality issues they produce.
Keywords:Semiconductor Industry; Power Quality; Power Quality Monitoring and Management; System Solutions
Introduction
Semiconductors are at the core of many industrial systems, widely used in fields such as computers, communications, consumer electronics, automotive, industrial/medical, and military sectors. To encourage the development of the semiconductor materials industry and break through industry bottlenecks, our country has introduced a series of policies to support the development of the semiconductor industry, providing a favorable development environment for the industry. Compared to other industrial buildings, semiconductor and electronic factories primarily differ in their high cleanroom standards, as well as the stringent requirements for power quality and voltage levels of precision equipment like lithography machines and plasma injectors. The majority of electronic products used in semiconductor production facilities employ nonlinear adjustable speed drives and variable frequency drives, which generate harmonic issues that degrade the quality of the public power grid. If left untreated, these issues can not only affect the normal operation of equipment but, in severe cases, even threaten patient safety. Therefore, in-depth analysis and research into the power quality management of semiconductor factory power supply and distribution systems is imperative.
2nd Harmonic Source Analysis
The semiconductor chip processing electronic factory's production manufacturing distribution system primarily includes harmonic loads from single crystal furnaces, multi-crystal furnaces, various precision equipment, lighting and variable frequency ventilation systems, computers, and UPS units.
Currently, most single crystal furnaces use a method of heating with medium-frequency induction power supply. The main circuit of the medium-frequency power supply includes rectification circuit, filtering circuit, single-phase bridge inverter circuit, and parallel resonance circuit. Among them, the rectification circuit employs a three-phase full-bridge rectification circuit, which functions to convert the three-phase 50Hz AC voltage into fluctuating DC voltage. The medium-frequency power supply of the single crystal furnace generates harmonic currents that only contain
(k=1,2,3...) times.
Monocrystalline and polycrystalline furnaces, IC test benches, PLC-controlled robotic arms, wafer manufacturing machines, and variable frequency-controlled semiconductor stations all generate a significant amount of harmonics. These not only cause malfunctions within the equipment themselves but also lead to overheating in other circuits when the harmonic currents return to the power grid. This can result in false operations of electronic switches, unstable power supply voltages, and even production line shutdowns or scrapping of semi-finished products, with considerable losses. Moreover, the frequent on/off operations of high-energy equipment such as epitaxy, diffusion, and ion implantation devices further exacerbate the deterioration of the electrical environment.
Harmonic Impact
3.1 Impact on the Power Grid
Increased power consumption in the power grid, reduced equipment lifespan, abnormal grounding protection and remote control functions, and increased heat in lines and equipment, especially the significant neutral current caused by the third harmonic, resulting in the neutral line current exceeding the phase line current, leading to unstable operation of the equipment. Consequently, harmonics can also trigger resonance in the power grid, causing disruptions such as the cessation of normal power supply, severe situations, and grid fragmentation. Resonance can lead to local parallel and series connections in substation transformers, damaging voltage transformer facilities; it also generates additional harmonic losses in the equipment and components of the substation system, causing the temperature of power transformers, cables, motors, and other equipment to rise, capacitor failure, and thereby accelerating the rate of qualitative change in insulating materials.
3.2 Impact on Electrical Safety
Firstly, fires have caused disasters. Many accidental fires are related to power harmonics. Currently, the on-off of power supply in energy-saving lamps and dimmer facilities is widespread. Initially, this was done to save energy, but these facilities have become harmonic sources, increasing the risk factor of the power grid, leading to an increase in neutral line current, which can exceed the line current severely, creating potential safety risks for fires. Secondly, equipment damage. Power quality can affect relay protection, computer systems, and precision instruments and machinery, causing them to operate and control unevenly, reducing the lifespan of facilities, and ultimately leading to avoidable accidental losses due to incorrect relay protection operations, causing various forms of interference. Thirdly, communication disturbances. The main factor for grid disturbances is the occurrence of harmonics, which, through basic electrostatic induction and electromagnetic induction, lead to audio confusion through communication lines. As the harmonic frequency increases, noise issues arise, causing audio confusion through communication lines.
3.3 The Impact of Harmonics on Electrical Equipment
First, the impact of power capacitors. As capacitors occupy a significant portion in the reactive power configuration capacity of the power grid, some capacitors are only arranged based on the reactive compensation amount, without considering the actual pollution status of the power quality at the installation point. Under severe conditions, series and parallel resonance may occur, leading to excessive voltage and current harmonics in the capacitors, causing capacitor cracking. Second, the impact of transformers. Harmonic currents in transformers increase copper losses, resulting in local overheating, vibration, increased noise, and additional overheating of windings. Third, the impact of synchronous generators. Negative sequence and harmonic currents flowing into synchronous generators within the system cause additional losses, leading to local overheating and reduced insulation strength. Fourth, the impact of automatic controllers. With digital control technology now being applied to a wider range of fields, many precise loads have higher requirements for power quality indicators. Consequently, contamination of power quality can lead to distortion variables in the monitoring modules of equipment, disrupt normal decomposition calculations, and cause erroneous output results.
Power Quality Monitoring and Management System Solutions for the Electronic Semiconductor Industry
4.1 Industry Characteristics
High Requirements for Power Quality:
The load contains multiple harmonic sources, resulting in a relatively high harmonic content in the distribution system.
Harmonics primarily consist of the 6N first harmonic.
There is an abundance of variable frequency equipment, posing risks of mutual resonance among these devices.
4.2 System Solution
Semiconductor chip manufacturing plays a crucial role in the national economy, with the scale of related enterprises growing increasingly larger. The stable and reliable operation of their power supply and distribution systems is not only a basic guarantee for their safe production but also affects product quality and the smooth progress of production. Integrated circuit chip manufacturing involves numerous key equipment, tooling, and complex process steps. In addition to the power supply and distribution system, transmission systems, ultra-pure water purification systems, vacuum systems, gas-cooled and air-cooled systems, and special gas distribution systems are required to ensure the smooth implementation of the production process and the safe operation of critical equipment. Since the entire factory's production conditions are ultimately achieved through electrical power supply, semiconductor chip manufacturing has particularly high requirements for power quality.
Ankorri Electric's power quality monitoring and treatment system solution meets the needs of power monitoring and management, operations, and power quality treatment. Committed to providing a one-stop comprehensive solution for the highway industry, the company aims to fulfill customer requirements from product, system, and service perspectives, thereby creating value for users.
4.3 Features
The Power Quality Monitoring and Management System offers local device-based services for power quality monitoring, management, and equipment maintenance. Additionally, by integrating with the AcrelEMS-SEMI Power Plant Energy Efficiency Management Platform, it provides users with remote online services.
Compliant with GB/T17626.30-2012 Class A accuracy measurement methods, suitable for situations requiring accurate measurement of power quality indicator parameters.
Specialized Power Quality Monitoring: Real-time online power quality monitoring with high measurement accuracy and precision, compliant with IEC61000-4-30 standard.
Interconnect Information for Power Quality Monitoring and Treatment Devices, conveniently managing both grid power quality and treatment data through a unified platform.
Utilizing three-level power electronic drive devices to output higher-quality regulated waveforms through more levels.
4.4 Plan Effect
Real-time high-precision monitoring of power grid energy quality, including voltage deviation, frequency deviation, harmonics, voltage fluctuations, flicker, and unbalanced three-phase voltage. The system also allows for recording fault events, trend analysis of load curves and voltage/current, voltage deviation, unbalance degree, and flicker at monitoring points. Users can view the waveform and trend analysis of alarm events through the system, and can also generate energy quality diagnostic reports based on the energy quality conditions of monitoring points.
By employing a governance strategy of centralized compensation plus on-site compensation, we enhance the compensation of reactive power and harmonic distortion throughout the data center, improving the power quality within the systems and the efficiency of electrical equipment supply. This significantly reduces equipment failure rates and meets the power quality requirements of automated equipment within the data center, effectively resolving issues of harmonic interference and false tripping.
The system offers a multi-dimensional tool for electricity consumption index statistics and electrical energy data analysis, providing guidance for the optimization of distribution system operation management and energy conservation.
Ankoray Power Quality Monitoring and Management System Product Selection
5.1 Comprehensive Governance
Within the electronic factory, electrical appliances such as fans and air conditioners are used. These appliances are scattered and produce relatively low harmonic levels individually. To ensure the reactive power factor meets the national standard requirements and avoid fines, a centralized treatment of power quality issues is conducted at the power distribution room for these loads. Additionally, online power quality monitoring of the entire low-voltage power supply and distribution system can be implemented, including harmonic analysis, waveform sampling, voltage dips/swells/interruptions, and flicker monitoring.
5.2 On-Site Governance
During the production of semiconductor devices, electronic factories require the use of controllable converter devices and variable frequency speed control devices, which generate a significant amount of harmonic pollution in the power grid during operation. If not addressed at the source, this can affect the voltage distortion rate, ultimately damaging other loads. To address this load situation, it is recommended to install power quality compensation equipment in the distribution boxes of all key equipment to locally treat the harmonics, achieving the goal of terminal harmonic treatment and preventing harmonics from affecting the entire distribution system and other electrical equipment.
5.3 Power Quality Monitoring and Management System
Platform Topology
The electric power quality monitoring and treatment system platform is mainly composed of four parts: electric power quality treatment equipment, physical gateways, servers, and service terminals. The electric power quality treatment equipment serves as the foundation for data collection and power quality compensation, while the physical gateways facilitate data transmission between devices and servers and distribute strategy functions to the devices. Data is ultimately presented to users through service terminals via the servers.
(2) Platform Display
The Power Quality Monitoring and Management System, in addition to providing local terminal services such as power quality monitoring, treatment, and equipment operation and maintenance to users, can also offer remote online services by integrating with the AcrelEMS Corporate Microgrid Energy Efficiency Management Platform.
Feature Showcase - Visual Management
- Project Site Information
- Plant Overview
- Distribution Room Information
- Equipment Compensation Operating Status in Substation
- Voice Alarm
- Error Information Popup
Effectiveness Comparison - Governance Analysis
- Load Side Harmonics 2-31 Histogram
- Power Grid Side Harmonics 2-31 Order Histogram
- Load-side phase voltage and current distortion rates
- Power line phase voltage and current distortion rates
Status Display - Equipment Operation
- Real-time monitoring of equipment compensation status
- Equipment operational status
- Fault Analysis and Description
Equipment Showcase - Operational Status
Capacitance Data Real-Time Monitoring
Switching State
Jiangsu Electronics Factory Energy Quality Management Project Case
6.1 Project Background
The electronic factory in Jiangsu not only produces core semiconductor devices but also houses transmission systems, water purification systems, air-cooling systems, and HVAC systems, all of which demand high electrical power quality. These equipment are non-linear loads that generate a significant amount of harmonics during operation, which are then injected into the system. Without harmonic mitigation, this can severely pollute the power grid, affecting the operation, interruption, or even paralysis of other sensitive equipment within the electronic factory, thus reducing the safety and reliability of the power distribution system.
6.2 Governance Plan
Based on past measurement experiences, harmonic analysis and estimation reveal that harmonics are primarily generated by single crystal furnaces, wafer machines, and certain non-linear loads. The power supply system consists of two 1200kVA transformers and employs a combination of centralized and on-site treatment approaches.
Centralized Management: Due to the widespread distribution of air conditioning and fan equipment in the electronic factory, a 400A active harmonic control system is installed under each transformer. This system is realized by paralleling two 150A modules and one 100A module, with the model being the whole cabinet type AnSin400-GⅠ. It automatically tracks and compensates for harmonic currents generated by the load, ensuring the safe and reliable operation of the power supply system.
On-site Harmonic Mitigation: As the single crystal furnace is a *malicious load in the center, it is necessary to mitigate the harmonic current it generates at the distribution end to avoid interference with other electrical equipment. Therefore, a wall-mounted ANAPF600-380/BBL active power filter is installed in the distribution room using the single crystal furnace, to locally mitigate the harmonic pollution generated by the single crystal furnace.
6.3 Governance Effectiveness
By comparing the waveform data before and after the power distribution box at the output end of the single crystal furnace in the factory, the voltage distortion rate, for example in phase A, was reduced from 10.45% to 5.58%, and the current distortion rate dropped from 28.94% to 5.67% after installing the wall-mounted ANAPF600-380/BBL active power filter unit, thereby improving the grid waveform quality.
Conclusion
The development of semiconductor material technology in China has led to the deployment of numerous semiconductor processing equipment, which commonly utilizes power electronic converters and control devices. These devices, while in operation, also generate a significant amount of harmonics. Not only do these harmonics cause malfunctions within the equipment itself, but the harmonic currents returning to the power grid can also lead to overheating in other circuits, erroneous operation of electronic switches, unstable supply voltage, and even halt production lines and scrap semi-finished products. Therefore, Ankorui has provided the electronics industry with a comprehensive system solution for power quality monitoring and treatment, effectively addressing the power quality issues in electronic factories. Considering cost, performance, and reliability, this method offers a high cost-performance ratio.
