Application of domestic PLC-IKON Drive PLC in photovoltaic power generation
Author: Xiamen IKON Drive Technology Co., Ltd.
Foreword: Photovoltaic power generation is based on the principle of photovoltaic effect, using solar cells to directly convert sunlight energy into electrical energy. Photovoltaic power generation has a wide range of applications, and has their presence in the transportation field, communication/communication field, petroleum, marine, meteorological fields, and residential electricity consumption. The impact is small, the system occupies a small area, and the land utilization rate is high. The photovoltaic power generation system is generally composed of solar cell arrays, battery packs, charge and discharge controllers, inverters, AC power distribution cabinets, sun tracking control systems and other equipment. This article will take a solar cell array as an example to introduce the application of Haiwell PLC in photovoltaic power generation.
Keywords: IKON Drive (IKON Drive) domestic PLC IKON Drive H01TCP-4 intelligent gateway photovoltaic power generation
1. Principle of sun tracking system
Tracking of daily movement trajectory. Compared with a solar photovoltaic power generation system at a fixed location, the sun rises and sets every day in four seasons of a year, and the sun’s illumination angle changes all the time. If the solar panel can always face the sun, the power generation efficiency will be improved. reach a better state. At present, the general sun tracking control system needs to calculate the angle of the sun at different times of each day of the year according to the latitude and longitude of the placement point, and store the sun position at each time of the year in the PLC, that is, by calculating Sun position for tracking.
Sensor tracking. Sensor tracking is to use the light sensor to detect whether the sunlight deviates from the baseline of the panel. When the sunlight deviates from the baseline of the panel, the sensor outputs a deviation signal, which is amplified and converted into a standard signal, which is transmitted to the PLC through the analog input channel. After the calculation, the actuator is controlled by the switch output, so that the tracking device is re-aligned with the sun.
2. Introduction of solar cell array network
1. Schematic diagram of a single solar cell square array network:
2. Schematic diagram of the network of 10,000 trackers in the photovoltaic power plant
There are often thousands of trackers in a photovoltaic power plant. Haiwell PLC and H04TCP-4 gateway are convenient and powerful for networking. Multiple solar cell arrays are connected to the optical fiber Ethernet switch, and they can be transmitted through Ethernet. Thousands of PLCs are monitored in the central control room. The network diagram is as follows:
3. Main hardware configuration of the system
3.1 Haiwell PLC
Haiwell PLC hybrid host comes with switch quantity and analog quantity, 6 channels of analog quantity input, the range is 0~10V, uses 12-bit AD conversion (generally 0~20mA), and supports direct access to optical sensors. The CPU host has 2 communication ports, which can be extended to 5 communication ports. Each communication port can be programmed and networked, and can be used as a master station or a slave station. Supports 1:N, N:1, N:N networking, supports various man-machine interfaces and configuration software, and can be networked with any third-party equipment with communication functions (such as inverters, meters, bar code readers, etc.).
3.2 Haiwell H01TCP-4 Intelligent Gateway
H01TCP-4 is a powerful hardware protocol gateway that converts various protocols from devices to standard Modbus RTU or Modbus TCP protocols. The gateway supports analog linear conversion, bit-taking function, and high-low byte exchange function; the gateway has a built-in WEB server, users can view the real-time changing data and communication status through the browser, which is convenient for on-site debugging; it comes with 4 communication serial ports and 1 Ethernet Ethernet port, each communication port has its own communication isolation. In addition, the intelligent gateway can also make a communication disconnection alarm for the slaves in each communication port network.
3.3 Optical fiber Ethernet switch, central control room SCADA system.
4. System data acquisition and control principle
Each tracker is a Haiwei PLC, which always receives the solar light position signal from the sensor, and sends it to the PLC through the PLC analog input channel. The PLC controls the rotation direction of the actuator through the user program calculation, so that the solar receiver is always facing the sun. Direct direction to obtain the maximum effective irradiation area.
The H01TCP-4 in a single solar cell array has 4 communication serial ports, each serial port is connected to 15 PLCs, and the data in the PLC is collected into the internal memory of the intelligent gateway for storage, for the host computer communication collection, monitoring and use. The host computer can also issue control commands, which are transmitted to the corresponding PLC of each serial port through the intelligent gateway. In addition, multiple solar cell arrays can be connected to the fiber optic Ethernet switch together, so that centralized control and monitoring of thousands of trackers in a solar photovoltaic farm can be realized.
3. System advantages
1. Haiwell H01TCP-4 only has strong gateway networking capability. Multiple solar cell arrays can be connected to the fiber optic Ethernet switch together, so that centralized control and monitoring of thousands of trackers in a solar photovoltaic farm can be realized.
2. Compared with traditional networking, the cost is greatly reduced. Traditionally, one PLC plus one Ethernet module is used to collect and monitor data for each tracker, which is costly; using Haiwell H01TCP-4 gateway module, one gateway can monitor the operation of more than 60 PLCs.
3. The intelligent gateway will make a communication disconnection alarm for each slave in each network. The management is convenient, but the traditional network management method is difficult, troubleshooting is difficult, and the human input is large.
4. Haiwell PLC has strong communication networking capability. The CPU host comes with 2 communication ports, each of which can be programmed and networked, and can be used as a master station or a slave station. Supports 1:N, N:1, N:N networking, supports various man-machine interfaces and configuration software, and can be networked with any third-party equipment with communication functions (such as inverters, meters, bar code readers, etc.).
5. Haiwell PLC programming software is fully simulated, and the analog quantity does not need to be converted between the code value and the engineering quantity through programming. It reduces the time for programming and on-site debugging, facilitates the debugging work of technicians, and improves work efficiency.