Converged processors provide core platform for smart grid

Digital technology has transformed the world and brought mankind into the information age. Whether it is consumer electronics, medical equipment, industry, automobiles, or aviation and military fields, digital technology is everywhere. However, the power system that provides energy for the information society has lagged behind in the application of digital technology. Due to various reasons, the power grid in most countries in the world is aging, the degree of digitization of power equipment and power management is low, the power use efficiency is low, and the power management methods are backward.

A financial crisis has turned the concept of smart grid, which is unfamiliar to most people, into a global hot topic. In order to promote economic recovery and as countries around the world face increasing pressure to save energy and reduce emissions, the energy-saving effect, huge market prospects and social effects of smart grid have attracted the attention of global giants including Google, Microsoft, IBM, etc., and even entered the national strategic planning of some major countries. Research data shows that by 2020, the world can reduce carbon dioxide emissions by more than 1 billion tons through the use of smart grids, which is about one-thirtieth of the carbon dioxide emissions in 2008.

Smart grids introduce the concept of "information flow", which combines power flow and information flow, collects data while transmitting energy, and promotes the rational and effective use and management of energy. Through the optimization model, data is deeply mined and analyzed to predict the power flow, such as voltage changes and power consumption distribution, and provide information decision-making for power generation, transmission, distribution, power consumption and regulatory units, ultimately achieving the goal of a smart grid with clean power generation, efficient transmission, dynamic distribution and rational power consumption.

There is no standard definition of the concept of smart grid in various countries. In fact, there is no unified standard for the standards and architecture of various links related to smart grid. Due to the differences in goals of various countries, the substantive connotations behind the concept of smart grid vary greatly. The definition of smart grid given by State Grid Corporation of China is to build a unified strong and intelligent grid characterized by informatization, automation and interactivity, with UHV grid as the backbone grid and coordinated development of power grids at all levels as the basis, using advanced communication, information and control technologies. Obviously, the support of China's (or the world's) smart grid will be communication technology, information processing technology and control technology, and the corresponding markets will involve smart metering (smart meters), grid intelligence (network infrastructure and its control) and information technology applications of utilities (intelligent data management). Each field means a huge emerging market, and also means that there will be complex related standard game rules behind it.

Figure 1: The changes in power management and application that smart grids will bring. [page]

Converged processors help you seize the opportunity

Before smart grid became a hot topic, the application of various digital technologies in power systems has gradually increased. Since relevant data is sampled and measured at the power generation, transmission, distribution and power consumption ends, this has created a lot of opportunities for analog-to-digital converters and MCUs to enter the power system. In recent years, the design ideas of power secondary equipment have shown a diversified trend, which is inseparable from the greatly improved diversification and flexibility of processors. With the development of intelligent technology requirements, data processing capabilities and communication processing capabilities are increasingly required, and the reality of multi-specification and multi-standard coexistence of products requires higher and higher design flexibility. Engineers have begun to shift their attention to DSP technology. The dual-processor solution of DSP+MCU solves the control and computing requirements of the system, but the increased development complexity and BOM cost have brought new challenges.

1. Unique advantages of converged processors

Siemens, a global leader in power equipment, has an important view on smart grids: flexibility - not only meeting the current needs of customers, but also being able to cope with the changes and challenges of future development. In fact, this flexibility requirement involves all basic equipment related to smart grids. For a long time in the future, responding to the changes and challenges of smart grid market demand will become the main theme for power equipment companies.

The transformation from traditional power grid to smart grid requires power equipment to have stronger interface capabilities, communication capabilities and data processing capabilities, which puts extremely high demands on the selection of hardware solution platforms for power equipment. This also responds to the current industrial applications and test and measurement support Ethernet/wireless connections for ease of use, simple connections for high-quality measurements, system programmability, and the development trend of shifting from 8/16 to 32-bit solutions. In addition, since the power grid is a closed network and involves major security issues related to the national economy and people's livelihood, it is difficult to unify smart grid standards around the world, and the coexistence of multiple standards will be inevitable. For this reason, product solutions that can flexibly meet multiple standards and functional requirements are very important, which makes the convergent processor solution platform that combines the advantages of MCU and DSP, has software design flexibility and powerful processing capabilities have obvious advantages.

Figure 2: Comparison of flexibility and computing power among MCU, DSP and ASIC solutions. [page]

Blackfin is a convergent processor launched by ADI. It is based on the micro-signal architecture jointly developed by ADI and Intel. It combines a 32-bit RISC-type instruction set and dual 16-bit multiplication and accumulation signal processing functions with the ease of use of general-purpose microcontrollers. This unique convergent architecture is very suitable for full signal processing/analysis capability requirements, while also providing efficient control task execution capabilities on single-core devices. This convergent architecture is very suitable for data processing of smart grid infrastructure equipment including smart meters, various high-performance algorithms (such as harmonic analysis), software implementation of communication functions, and support for various system control functions.

Solutions based on Blackfin processors can easily use software to implement different power metering-related protocols and various communication protocol algorithms, as well as meet various functional combination requirements. The powerful processing power of Blackfin processors enables power equipment manufacturers to easily implement various general or customized functions, and can quickly adapt to evolving standards and new functional requirements without changing (or rarely changing) hardware, and greatly reduce product development and manufacturing costs.

Since launching the first convergent processor product in 2001, ADI has launched several series and dozens of products with various functional combinations and performance characteristics, ranging from 300MHz to 756MHz, from single-core architecture to dual-core architecture, with the lowest price as low as less than US$5. The powerful processing power, high performance and low cost are in line with the development direction of the power secondary equipment market.

In terms of peripherals, the Blackfin series provides a wealth of choices, including on-chip Flash, SDRAM or DDR controller, parallel interface PPI, asynchronous serial interface UART, synchronous serial interface SPORT, serial master-slave control interface SPI, I2C, general timer, watchdog, real-time clock, GPIO pins, etc., thus providing customers with great design convenience and abundant available on-chip design resources.

ADI also provides industry-leading tools, starter kits and support, including the well-known ADI CROSSCORE® software and hardware tools that can support other Blackfin processors, including VisualDSP++® integrated development and debugging environment (IDDE), simulators, and EZ-KIT Lite® evaluation hardware. Because Blackfin provides a complete hardware reference design and software development environment, it is very convenient for power secondary equipment customers to migrate old application solutions or redevelop new application solutions.

At the same time, ADI has a global leading position in the fields of sensors (such as electric meter measurement chips), analog-to-digital/digital-to-analog converters, operational amplifiers, and power line communications. The optimized system solution platform based on the Blackfin processor and ADI's leading analog device technology and power line communication technology will help form a seamless high-performance component platform and achieve the optimization of functions and performance. [page]

2. Extensive successful design verification

The application history of ADI's DSP processor products in power equipment can be traced back to the 1990s. As ADI has always had a good reputation and products in the field of industrial applications, ADI's ADC, operational amplifiers and DSP processors are widely used in the design of power secondary equipment. Among them, the DSP processors mainly use the fixed-point DSP processor ADSP21XX series and the floating-point DSP processor ADSP2106X series.

Due to the insufficient processing power of DSP or MCU in the past, most of the old design solutions adopted multi-processor architecture. With the continuous improvement of market requirements for equipment cost and development cycle, and the continuous improvement of DSP processor performance, new power secondary equipment designs are increasingly adopting single-chip design ideas represented by Blackfin convergent processors. This can not only greatly reduce equipment costs, but also simplify the development platform and save a lot of development costs.

Blackfin processors have been widely used in power systems since their introduction. Nanjing NARI Relay Protection Electric Co., Ltd., a global leader in digital protection, automation and control systems for HVAC and HVDC power systems, uses Blackfin processors in many of its products, while most embedded processing was previously based on general-purpose microprocessor architectures. NARI Relay Protection has found that the superior performance of Blackfin processor solutions effectively ensures the reliability of the national power grid in critical applications such as detection and response to grid faults and transient events. High performance is definitely a very important factor in the success of Blackfin digital signal processors in these industrial applications. The ability to connect input and output devices such as converters and switches is also very important. The ability to quickly measure and analyze system conditions is also another important factor. In addition, low power consumption and low cost are also a significant reason for choosing ADI DSP in so many applications. [page]

(III) Analysis of typical application cases

The main beneficiaries of power grid construction are smart meter manufacturers and secondary equipment companies. As smart meter technology is relatively mature, the development speed of intelligent distribution network will be faster than that of transmission network. In the early stage of smart grid construction, the demand for secondary equipment, mainly grid dispatching system and digital substation, will increase greatly. AMI (Advanced Metering System) is the first step in the intelligent construction of power grid, accounting for the largest proportion of investment in smart grid, mainly involving a large number of smart meters, sensors and other equipment

Not long ago, Siemens, a global leader in power metering technology, announced that the core engine of its latest automatic meter information system (AMIS) smart meter uses the cost-effective computing performance of the Blackfin processor - BF531, to achieve innovative smart meter functions and performance, setting a new benchmark for the next generation of smart power management. The Siemens AMIS system covers the entire power system, from power plants to users. As a user metering terminal, the smart meter measures the user's electricity consumption, monitors the power grid, and sends the data to the control center.

The system uses power lines for communication, avoiding the increased costs of wireless and Internet communications used by other solutions. The system has excellent expansion flexibility and remains open to other possible standards in the future (including support for other communication media). New standards can be implemented through simple online software download upgrades. With the AMIS multi-functional smart meter, a single meter platform can meet all charging modes, and the meter's billing mode can be automatically modified in the control center. Therefore, there is no need to change the meter for each rate modification. You can automatically collect user electricity data at any time according to user requirements, and you can remotely control user power outage operations without going to the site. You can realize prepayment functions or power consumption restrictions. Power companies can also record the power supply quality for each user (voltage, short-term faults and long-term faults at each stage, etc.).

At the beginning of AMIS design, Siemens realized that to achieve the above functional characteristics, these smart meters need to provide extraordinary in-meter processing capabilities, dynamic and grid-integrated communications, and true scalability at a low unit price. Siemens chose the Blackfin convergence processor because it has the ability to work seamlessly as a DSP and MCU at the same time. The Blackfin processor is responsible for calculating the user's electricity consumption and performing the power line modem function. It performs efficient two-way communication through the power line concentrator, which is particularly suitable for the high-density processing and dynamic communication application requirements of Siemens AMIS. The low-cost Blackfin processor has the ability to process raw real-time electricity consumption data at the meter level and realize communication between the meter and the power grid, providing a one-stop, low-cost, and easy-to-configure solution.

Figure 3: Functional block diagram of a Siemens smart meter based on a Blackfin processor.

In addition to its large on-chip memory and low power consumption, another important reason why Siemens chose Blackfin is that the processor supports programmability. Siemens' main market is in Europe, but the EU has not yet unified the standards for power line communication. Power line communication in different countries can have different changes, so Siemens needs to support smart grids with different standards. With the programmable characteristics of Blackfin, changes can be made to support different power line communication standards even after the meter is installed. Blackfin-based smart meters can not only meet current design requirements, but also prepare for the next generation of technology updates. With the development of future standards, these applications can be downloaded to Blackfin-based meter components simply through the power grid to achieve seamless transmission.

In fact, Siemens' experience in choosing Blackfin is also of reference significance to the secondary equipment of smart grid and all power metering equipment companies. The standards of smart grid (including product function definition) will continue to evolve over a long period of time and it is difficult to achieve global unification. The design flexibility and scalability of the product solution platform are crucial for companies to meet the global market. [page]

ADI Creates Comprehensive Technology Solutions for Smart Grid

ADI is an important force in promoting the development of the global power industry. As a leading company in analog semiconductor technology, its sensors, amplifiers, analog-to-digital converters and other products are widely used in power secondary equipment. According to statistics, more than 225 million electric meters in the world have adopted ADI's electric energy metering technology. ADI's power metering chips are world-renowned for their high quality, high reliability and high performance. Now, ADI's industry-leading convergent DSP technology will continue to play an increasingly important role in global smart power metering applications. The wide range of semiconductor solutions provided by ADI helps power equipment companies successfully cope with the design challenges posed by various links from electric meters to substations. In the future, ADI will further improve chip integration and integrate mixed signal processing, Flash and new interfaces into DSP.

Engineers developing “smart grid” technologies rely on ADI’s advanced digital and analog signal processing technologies to advance the next generation of energy infrastructure. ADI’s integrated circuits are optimized for a variety of smart grid applications, from meter solutions to dynamic management and communication systems for grid integration. For power infrastructure and user-side applications, ADI’s technology enables development engineers to design intelligent systems that improve energy efficiency and management flexibility. ADI’s integrated circuits are optimized for a variety of smart grid applications, from meter solutions to dynamic management and communication systems for grid integration. For power infrastructure and user-side applications, ADI’s technology enables development engineers to design intelligent systems that improve energy efficiency and management flexibility.

ADI sees the huge potential market for power applications and is committed to providing users with the most optimized technical solutions. Not long ago, the company announced that it would cooperate with NARI Relay Protection Electric Co., Ltd. to jointly establish its first joint laboratory in the industrial field in China to strengthen the application research of analog and digital signal processing technology in the field of power system automation. NARI Relay Protection will put forward requirements and feedback on signal processing technology from the perspective of power system automation applications, and then ADI will design chips that meet the application of power system automation, thereby improving the application level of analog and digital signal processing technology in the field of power system automation and reducing the application cost of signal processing technology in the field of power system automation. ADI has also established a similar joint laboratory with another Chinese power system automation and relay protection device R&D company, Beijing Sifang Relay Protection, to strengthen technical support for Chinese power equipment companies through close cooperation with local companies.

The Chinese government is drafting a smart grid development plan and has already started the pilot work of smart grid applications. At the same time, based on the unified management system of China's State Grid, China will be a pioneer in the development and application of smart grid technology. China is not behind any other country in terms of smart grid technology research or technology application. Chinese local companies will seize this wave of digitalization and will surely usher in opportunities for rapid development.