Friends in the photovoltaic field are no strangers to microinverters. The CC2340 is unfamiliar to everyone. Who is it? What does it have to do with microinverters? You also said it could lead to the next era of microinverters? Don't worry, let's take a look together.
At a time when the world is working towards a dual-carbon vision and the European fossil energy crisis brought about by the Russo-Ukrainian war, distributed photovoltaic power generation is increasingly valued by the new energy community for its ability to supply green energy and enhance grid resilience. It is welcomed and encouraged by the regulatory authorities of various countries. Since the emergence of micro-inverters at the beginning of this century, after several developments, it has become an indispensable part of the field of distributed photovoltaic power generation in developed areas. It can not only improve the conversion efficiency of photovoltaic modules in actual field work, but also greatly Improve the safety and stability of the entire power generation system to a great extent. Global microinverter shipments are expected to reach 13.39GW in 2023, and will maintain an annual growth rate of 70% in the next five years. There are currently two communication methods for photovoltaic micro-inverters, one is cable connection communication, and the other is wireless communication method (mainly ZigBee technology). The wireless method has become a market development trend due to its convenient installation, natural electrical isolation effect, and higher security. The large-scale application of new technologies, in addition to solving our problems, also needs to bring sufficient cost-effective advantages and reduce the entry cost of application promotion. The CC2340, a wireless communication chip launched by Texas Instruments that supports Zigbee, was born precisely for this new trend. This may be something that its developer, TI, is not aware of either. why? Sir, please continue reading.
ZigBee is a low-rate short-distance wireless communication technology. Its biggest feature is that it naturally supports MESH networking, making its stability and networking capabilities excellent. In addition, the localized deployment of ZigBee brings good stability to various special situations. ZigBee-based products can complete work in micro-inverter systems and have high stability and networking capabilities. Microinverters are suitable for household or small industrial and commercial systems, and are very suitable for ZigBee networking.
Figure 1 Microinverter
TI has already made plans in the ZigBee field. Its CC2530 and CC265x are widely used. TI's newly launched CC2340 achieves rolling advantages in terms of cost performance. The SoC is available in 4x4 RGE QFN24 and 5x5 RKP QFN40 packages, with a 48MHz MCU, standby power consumption of 710 nA, sleep power consumption of 150nA, receiving current of 5.3mA, and the transmitting current is less than 11mA at the highest transmit power of +8dbm. These performances have been greatly improved compared to previous generations of chips. In this case, TI posted a starting price of just $0.79. The use of TI CC2340 is bound to improve the wireless communication performance of micro-inverters and effectively reduce the terminal cost of the solution, creating sufficient competitive advantages for manufacturers. The following table is a parameter comparison of TI CC2340, CC2530 and CC265x Soc.
Table TI 2340, CC2530 and CC265x SoC comparison
In the micro-inverter system, each component has an independent MPPT. The power generation between the components does not affect each other. Control of each component can be achieved, that is, component-level control. Through the intelligent operation and maintenance system, each component can be viewed The location and power generation status and other information can be used to locate faults faster and more accurately.
The micro-inverter system adopts ZigBee wireless communication method. The energy communicator ECU and micro-inverter have built-in ZigBee modules to achieve network self-healing, multi-level jumps, and optimized path communication. Through the ZigBee MESH mesh network, the energy communicator ECU is responsible for collecting and transmitting the microinverter power generation data. Data can be uploaded to the cloud platform through wired/Wi-Fi/4G gateway access to the Internet. Users can check the power generation status of the system anytime and anywhere through terminal devices such as computers or mobile phones to achieve real-time monitoring, intelligent alarms, statistical analysis, remote upgrade control, etc. . The MESH network topology has a flexible communication mode. When one of the inverters has a problem, the data can also be automatically transmitted along other inverters or directly to the energy communicator ECU, without communication problems with one inverter. And affect the communication of the entire system. Each ECU can monitor hundreds of inverters. The micro-inverters have wireless signal relay functions and can relay communication information. The entire system network is built into a MESH self-organizing network, with faster and more stable transmission speeds.
Figure 2 ZigBee networking of micro-inverter system
►►► ZigBee wireless communication technology features
01. Low power consumption
ZigBee's low power consumption standby mode allows two AA dry batteries to support the operation of a node for 6-24 months, or even longer. In comparison, Bluetooth can only work for a few weeks and Wi-Fi can only work for a few hours, which is the outstanding advantage of ZigBee.
02. Low cost
By greatly simplifying the protocol, ZigBee's cost is very low, less than 1/10 of Bluetooth, which reduces the requirements for communication controllers. According to predictive analysis, using an 8051 8-bit microcontroller, a full-function master node requires 32 KB of code, and a sub-function node only requires 4 KB of code. In addition, the ZigBee protocol patent is free.
03.Low rate
The communication rate of ZigBee is 250 kbps, which is suitable for application requirements for low-rate data transmission.
04. Close range
The transmission range of ZigBee is usually between 10 and 100 meters. By increasing the RF transmission power, the transmission range can be extended to 1-3 kilometers. These transmission distances are the distances between adjacent nodes. The transmission distance can be further extended through routing and relays between nodes.
05.Short delay
ZigBee has a fast response speed, it only takes 15 ms to convert from sleep state to working state, and it only takes 30 ms for a node to connect to the network. It not only improves the response speed, but also saves power. In comparison, Bluetooth takes 3~10 s to establish a connection, and Wi-Fi takes 3 s to complete the connection.
06.High capacity
ZigBee can adopt star, slice and mesh network structures, with one master node managing multiple child nodes. A master node can manage up to 254 sub-nodes. At the same time, the master node can also be managed by the upper layer network nodes, which can form a large network of up to 65,000 nodes. This high-capacity architecture can accommodate applications of varying sizes and complexity.
07. High security
ZigBee provides three levels of security modes, including no security settings, the use of access control lists (ACLs) to prevent illegal acquisition of data, and the use of symmetric ciphers using the Advanced Encryption Standard (AES128) to determine its security attributes. This flexible security setting can meet the security needs of different applications and protect data from unauthorized access.
08. License-free frequency band
ZigBee uses the Industrial Scientific Medical (ISM) frequency band, which includes 915MHz (United States), 868MHz (Europe) and 2.4GHz (global), and can be used free of charge without application.
Shenzhen Xinchida Technology combines the needs of micro-inverter systems and the IoT composite track. After launching the CC2530 series ZigBee modules and the CC265x series multi-protocol wireless modules (supporting the ZigBee protocol), it launched the RF-based TI CC2340 wireless SoC The BM-2340Bx series ZigBee module can embed a micro-inverter, allowing users to remotely read micro-inverter data and remotely control it.
RF-BM-2340Bx series wireless modules support ZigBee self-organizing network technology, +8 dBm transmit power, have multiple package sizes, support wireless output methods of PCB antennas and IPEX sockets, and have high performance, low power consumption, high reliability, It has the characteristics of high cost performance, flexible and convenient networking, and supports large-scale node networking. With the launch of TI's CC2340 series SoC, we can expect it to have large-scale applications in the micro-inverter market, especially CC2340-based ZigBee modules. Therefore, let us wait and see how the CC2340 SoC performs in the market.
About Xinchida
The R&D team of Xinchida Technology has many years of experience and technology accumulation in the wireless communication module industry, and is committed to providing customers with high-quality wireless radio frequency solutions and product services. As a third-party IDH of TI in the United States, Xinchida Technology will continue to promote the market popularization and technological progress of Bluetooth and multi-protocol products, provide all-round support for TI's fourth-generation wireless SoC----CC2340, and accelerate its success in the market. promotion and application.