Smart meters are an integral part of the smart grid construction process. The original electric energy meter generally adopts a mechanical structure, and the smart meter adopts an electronic structure, so the performance requirements of the semiconductor and its expectation as an emerging market are quite high. In addition, communication with low power consumption, information and payment, which can extend battery drive time, will also become an important factor. Therefore, we will explain the development trend of smart meters and existing problems, and introduce Renesas Electronics' solutions in smart meters.
Build different measurement units depending on the region and the public utility
It is the primary prerequisite for building a smart grid to fully popularize the use of electricity, water, gas, etc., and the intelligent instrument with communication function. In the past, the role of electricity meters was only to improve the efficiency of electricity consumption statistics and prevent electricity theft by remote meter reading. However, with the focus on power saving and energy saving brought about by the use of power consumption, in order to build a distributed power supply through the smart grid, and to grasp the detailed information of power demand, various demands such as power outages are prevented from expanding globally. In particular, since various types of electric energy meters have been mechanically constructed in the past, and smart meters have adopted an electronic structure, people are increasingly expecting new markets brought about by semiconductor performance and smart meters in smart meters.
The smart meter is composed of a measuring unit, a communication unit and a switch unit. (Figure 1) The main unit of the measurement unit is the statistics on electricity consumption and related expenses. The communication unit is used for communication with public utilities. The switch unit, as the name implies, controls the supply of electricity or gas. Taking a smart meter as an example, it consists of measuring the current/voltage measurement part, and the MCU part based on it for power and cost calculation, the display part, the EEPROM storing the cost information, and the optical coupling that makes the connection of the communication unit in an insulated state. And so on. However, due to the different regions and public institutions, the development of smart meters is also very different. This leads to the internal structure of the smart meter divided into three types, and the main component of the smart meter MCU also has a great difference in operation and performance.
Figure 1: Block diagram and configuration example of a measurement unit for a smart meter
The first is to calculate the cost only through the software of the MCU. This type of meter generally requires only an 8-bit MCU because it requires only basic calculation functions. At the same time, since this type of meter is processed almost entirely by hardware, low power consumption can also be achieved. In addition, such meter memory is small in size, low in cost, and requires no development of power measurement related functions, thereby shortening the development cycle. Especially for the Chinese market, which is biased towards a short development cycle, it has great advantages.
The second is that power calculations are also carried out through software. This meter requires a high speed 16-bit MCU. More flexibility than the first. It is very suitable for the Indian market with rich software development talents.
The third type is to be sensed by the MCU's A/D board, and the software performs filtering processing, power calculation, and cost processing. For greater flexibility, the general-purpose single-phase power supply and industrial-oriented three-phase power supply can be supported by software changes. However, since it is required to have higher computing power, it requires a 32-bit MCU with DSP function. Therefore, there is a high demand in the US and European markets where development efficiency and additional services are valued.
Due to the diversified composition of the measurement unit, the corresponding MCU products are also very different. Renesas Electronics has an MCU product line that can correspond to the above various types of meters. For example, for the first type of meter, Renesas Electronics owns R8C and 78K0 with single-phase power unit. For the second and third categories, we have 78K0R, V850, H8S and upcoming RX200 products. (Fig. 2) Renesas Electronics can provide MCUs with the main components as the center, including measuring the current/voltage measurement section, display section, EEPROM that can store cost information, and ICs and power devices with many other functions. Smart meter solution.
Figure 2: Instrumentation-oriented MCU development blueprint
Support multiple communication units with standard products and ASICs
The communication unit typically has two systems depending on the communication location. One system is the Neighborhood Area Network (NAN) for transmitting fee information to the utility; the other is the Home Aria Network (HAN) that the smart meter needs to implement the gateway in the user's home.
First, the NAN system has two modes of power line communication and wireless communication depending on the region of use. In the United States, grid communication is mainly used in the 900MHz band, while in China and Europe, power line communication is the main. At present, wireless communication is mainly used in Japan, but it is also considering whether to adopt a specific low power, 950MHz, PHS, and the like.
On the other hand, the HAN system may use wireless methods such as WiFi, ZigBee, 6LoWPAN, and Z-Wave, or wired methods such as power line communication and EtherNet.
Therefore, the semiconductors required for the above communication units are also different due to differences in public utilities and regions. In response to this situation, Renesas Electronics is currently developing an auxiliary gigahertz band wireless IP core and multi-modulation IP core for standard products. There are more ASICs to choose from. Renesas Electronics can customize products that meet the needs of customers in a short period of time according to the communication methods required by customers. As far as ASICs are concerned, due to the advanced technology they use, they can fully realize low power requirements.
Hardware encryption engine and tamper-proof function for improved security and peace of mind
However, after the instrument has a communication function, there are also drawbacks. One of the most worrying issues is hacking. If the lifeline of the grid is stopped after the communication is attacked, it may cause serious disasters. The key to solving this problem is to perform communication encryption. Among them, there are two elements, such as routers and other products, "high-encryption technology for anti-communication attacks", and "tamper-proof function" for encrypting MCU internal information in order to prevent internal attacks. Renesas Electronics also has two technologies: a highly hardware encryption engine and a highly tamper-proof function for secure transmission. This has a strong advantage for a semiconductor manufacturer. Thanks to these technologies, Renesas Electronics is about to launch a NAN system with safety features required by customers.
In addition, with its peripherals such as EEPROMs and optocouplers, Renesas Electronics can provide almost all of the major semiconductor products required for smart meters. In the future, Renesas Electronics will continue to provide more solutions for smart meters that are constantly expanding demand.
Withstand high voltage up to 750V (IEC/EN standard)
UL 94V-2 or UL 94V-0 flame retardant housing
Anti-falling screws
Optional wire protection
1~12 poles, dividable as requested
Maximum wiring capacity of 4 mm2
Feed Through Terminal Block,T12 Series Terminal Blocks,Terminal Strips Connector,Cable Connectors Block
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