A brief discussion on ADI's complete solution for smart grid

China State Grid announced that it will build a nationwide smart grid by 2020, and has invested 4 trillion yuan in basic design and construction. The implementation of this grand plan will involve a wide range of related fields such as new energy power generation, new energy grid access, large-capacity energy storage, ultra-high voltage transmission, digital substations, and smart metering, opening up an unprecedented huge market for global power equipment companies, while also posing higher technical challenges to semiconductor manufacturers and equipment manufacturers.

　　There are many key challenges in the construction of smart grids. "We can see more demands including high-precision analog-to-digital converters and precision operational amplifiers, processors and controllers that support network functions, long-life, wide temperature range, high-reliability isolation devices, etc." said Singer Zhang, technical business manager of ADI, at the recent "2012 Industry Development Trends Media Seminar".

　　ADI has been involved in energy-related semiconductor solutions for more than ten years, and in 2009, it established a new organization dedicated to smart grid and other energy applications. It has a wide range of product solutions from energy metering chips to control system solutions for all aspects of the comprehensive energy and power system. It has always maintained a leading technological advantage in power transmission and distribution, relay protection, measurement and control systems, power metering and energy control, and has a high market share. Faced with the huge opportunities brought by the gradual global popularization of smart grids, what are ADI's observations? What leading technical support can it provide?

　　Figure 1: ADI can provide leading technology solutions in all aspects of generation, transmission, distribution and use.

　　In the power generation sector, the prospects for new energy are still promising

　　NPD Solarbuzz's China Project Report recently pointed out that many photovoltaic manufacturers have made grand plans to independently or cooperatively develop hundreds of megawatts of projects in China in 2012. Many industry insiders have also pointed out recently that after the reshuffle and decline in the second half of last year, the cost of the current photovoltaic market has dropped significantly, and the cost of building power stations has been greatly reduced, and the market has begun to show a hot trend again. In terms of wind power, according to the "Emerging Energy Industry Development Plan", in the offshore wind power plan alone, China's installed capacity during the "12th Five-Year Plan" period is 5 million kilowatts, and the installed capacity will reach 30 million kilowatts in 2020.

　　Although new energy represented by wind power and solar photovoltaics once faced a roller coaster-like market reversal in 2011 after enjoying rapid growth, it is undeniable that new energy still has a bright future. "In the field of power generation, new energy will be the main trend in the future. We will also spend more time focusing on the new energy field." Singer said, "At present, Chinese companies occupy a leading position in the global market in the field of new energy equipment manufacturing. ADI looks forward to helping Chinese companies further improve their competitiveness in technology."

　　The main technologies involved in renewable energy power generation include the design and assembly technology of high-power wind turbines, generator control technology, high-power conversion technology, MPPT control of photovoltaic systems, photovoltaic inverter technology and grid-connected technology. "In these aspects, ADI has relevant technologies to provide support, especially ADI's high-precision converters and operational amplifiers to ensure the precise measurement of voltage and current of renewable energy." Singer pointed out, "For example, the bus current of the inverter is detected and electrically isolated. ADI's AD7400 and AD7401 can greatly reduce system complexity and improve integration and stability because they integrate Sigma-Delta modulators and ADI's patented iCoupler isolators. At the same time, for some systems that use Hall devices for isolation, ADI also provides precision ADC as a converter for bus current detection. In addition, for some applications that require motor speed/angle detection, since the system requires extremely high stability, RDCs such as AD2S1210 can provide the system with a simple and stable sine/cosine signal processing conversion channel."

　　Figure 2: ADI provides a wide range of solutions in new energy fields such as wind power, solar power, and energy storage.

Power transmission and distribution: new technologies and standards give rise to a large market

　　"Since the power of renewable energy generation is uncontrollable, the power output is volatile and intermittent. When the scale of grid connection reaches a certain level, the power distribution of the power grid will change. The power control of the traditional power grid will undergo a major change, which will directly affect the stability of the power grid." Singer pointed out. The uncertainty of renewable energy generation has brought about power fluctuations that have reduced the quality of power grid power. Solar power generation will also have an island effect. The use of traditional power grid protection and measurement and control equipment cannot meet the requirements, and newer power grid protection and control equipment is needed.

　　Figure 3: Singer: ADI looks forward to helping Chinese companies improve their global competitiveness in technology.

　　"These problems that arise after the large-scale use of new energy have put forward a realistic demand for smart grids. It is necessary to digitize and intelligentize substations in different regions from the traditional standards to ensure the balance of the entire power grid." Singer said. This transformation will require a lot of infrastructure to be upgraded and updated, which will undoubtedly bring about huge market opportunities for power infrastructure equipment. "Take automated substations as an example. The State Grid plans to achieve 6,100 automated substations in the next five years. This alone is a very large market." Singer pointed out.

　　However, the cost of implementing automated substations based on the IEC 61850 standard is still very high, which puts great pressure on the transformation of the huge power grid system. "ADI hopes to help reduce the cost and promote the advancement of China's power grid intelligence." Singer said, "Currently, there are very limited solutions on the market that support IEC61850 in the core processor field. ADI will soon launch a very 'powerful' core processor that supports this standard." Singer smiled and revealed ADI's key product plan.

　　The transformation of smart grid will not only bring about the technical upgrade of substations, but all power secondary equipment will need to meet the requirements of stronger interface capabilities, control capabilities, protection capabilities, measurement capabilities, communication capabilities and data processing capabilities. In addition, some secondary side equipment functions such as some detection functions will be transferred to the primary side, which will also bring challenges to related product designs, especially to chips, because most of the primary equipment is outdoors, and the requirements for temperature range, anti-interference and special environments are increased. "The requirements for IC temperature drift, anti-interference, isolation and other performance are significantly higher than traditional solutions. Taking isolation as an example, optical isolation will face challenges in high temperature, high heat and long life requirements." Singer pointed out, "and these are exactly what ADI excels in. For example, the patented iCoupler digital isolation technology can well overcome the shortcomings of traditional optocoupler isolation with high environmental requirements."

　　Electricity metering, smart meters are on the rise

　　"China was the first country to implement electronic electricity metering, and it was carried out very thoroughly. Now, China is also taking the lead in rapidly promoting the popularization of smart meters." Obviously, Singer is very pleased that China is at the forefront of the world in electricity metering technology. In fact, with the launch of the global smart grid market, the intelligentization of electricity meters is in the ascendant, and China and major countries in the world will usher in a peak period of smart meter installation that will last for several years.

　　Electricity metering is no longer the only function of smart meters. Information collection, analysis and interactive management of electricity usage - using advanced intelligent analysis tools to generate useful information, and then using this to make better electricity decisions and optimize power system configuration in real time, will be the functional requirements of smart meters in the future. The advancement of smart meter technology will enable individuals and companies to choose how and when to use electricity, reduce energy waste and achieve reasonable use of electricity. Power companies can analyze the collected electricity information, discover existing problems or even power failures in a timely manner, and provide electricity consultation for users. Electricity meters have developed from simple basic metering to multi-functional trends such as automatic meter reading, information collection, and automatic control.

　　ADI is undoubtedly a pioneer in the field of electric energy metering. It has successfully launched electric energy metering devices very early and has always occupied a leading market advantage. As a basic requirement, the metering function is still the most important for smart meters, and higher requirements are placed on key characteristics such as accuracy and dynamic range. ADI has launched a variety of high-precision electric energy metering chips to solve these metering needs, including single-chip metering conversion chips ADE7858, ADE7868, ADE7878 and ADE7953, which can greatly simplify the system hardware and software design. If higher metering accuracy is required, simultaneous sampling ADCs such as AD73360 and AD7606 can achieve high-precision metering of 0.1s-0.2s.

　　In addition to high-precision metering ICs, ADI's devices support almost all functions of the metering system, including isolation, power management, and multiple types of communications. "An important function of smart meters is to realize autonomous communication of meters. ADI is also a leader in this field, and we have been doing in-depth research and development." Singer pointed out. It is reported that ADI is the main supplier of RF integrated circuits in the deployment of wireless mesh networks in the United States. In China, ADI has entered the market with its power line carrier communication solution based on the new OFDM technology. Compared with the FSK communication protocol commonly used in power line communication, this technology has superior communication reliability.

　　Figure 4: Siemens smart meters use Blackfin processors from Analog Devices.

　　“In China, wireless communication technology and power line carrier technology have begun to be used in meter reading and communication, and will soon transition to smart meters. ADI has very strong capabilities in both technologies and can provide corresponding technical solutions to support the development of China's smart grid,” said Singer.