overview
Distributed photovoltaic power generation projects are generally divided into 380V and 10KV according to the grid-connected voltage level. The general voltage level is 380V, and the low-voltage grid-connection basically does not involve any secondary products. It can usually be solved by using photovoltaic grid-connected cabinets. The common grid-connected equipment is mainly anti-islanding protection devices and online power quality monitoring devices. However, projects with 10KV grid-connected photovoltaic capacity generally between 1MWP and 10MWP need to be used for photovoltaic secondary equipment. The common secondary equipment involved in this includes photovoltaic background monitoring system, telecontrol communication screen, dispatching data network screen, photovoltaic secondary security screen, photovoltaic secondary equipment prefabricated cabin, anti-islanding protection device, power quality online monitoring device, fault release device, etc.
Photovoltaic background monitoring system
The function is to monitor the data in the substation in real time. At the same time, it can remotely control the closing and opening of some power station switches, adjust the parameters of electrical equipment, and so on. The photovoltaic background monitoring system is to connect the inverter, combiner box, irradiator, meteorological instrument, electric meter, microcomputer protection device and other equipment of the photovoltaic power station through data lines, use photovoltaic power station data collectors, communication management machines, data gateways and other equipment for data collection, and upload them to user servers or local computers through GPRS, optical fiber, etc., so that users can view relevant data on the Internet or local computers, which is convenient for power station managers and users to view and manage the operating data of photovoltaic power stations. It can monitor and control the battery array, combiner box, inverter, AC and DC power distribution cabinet, and other equipment in the solar photovoltaic power station in real time, and quickly grasp the operation of the power station through various styles of charts and data. Its friendly user interface, powerful analysis function, and perfect fault alarm ensure the complete reliability and stable operation of the solar photovoltaic power generation system.
Photovoltaic remote screen
It is generally composed of telecontrol communication devices, protocol converters, switches, lightning protection devices, etc. Telecontrol communication screens are equipment for remote monitoring of plant information and remote removal of power grid loads based on the safety construction of the power grid; the main channel is composed of telecontrol devices, communication management machines, switches, GPS time synchronization devices, digital channel lightning protection devices, analog channel lightning protection devices, screen cabinets and accessories. The substation telecontrol communication system refers to a system that monitors and controls the production process in a wide area. It includes all equipment and functions such as the collection, processing, transmission, display, and execution of necessary process information. The equipment constituting the telecontrol system includes the station-side telecontrol device, the dispatching-side telecontrol device and the telecontrol channel.
Photovoltaic dispatching data network
Photovoltaic dispatch data network is used to transmit power grid automation information, dispatch command instructions, relay protection and safety automatic device control information, etc. This service is completed by the router, the power vertical encryption equipment is responsible for encrypting the data, and the switch is the supporting equipment. Dispatching data network equipment is generally composed of 2M services and 100M services, each group is equipped with 1 router, 2 vertical encryption devices dedicated to electric power, and 2 switches. The router is responsible for data service transmission, two vertical encryption devices divide real-time information area and non-real-time information area, and one vertical encryption device is matched with one switch for business processing. A complete set of dispatching data network equipment for the power main network is generally configured with 2 routers, 4 vertical encryption devices dedicated to power, and 4 switches.
Photovoltaic secondary security screen
The secondary security screen is to ensure the security of the power information system, power real-time closed-loop monitoring system and dispatching data network. The goal is to resist malicious damage and attacks on the system initiated by hackers, viruses, malicious codes, etc. in various forms, so as to prevent the occurrence of accidents such as primary system and secondary system accidents or large-scale power outages. It is a composite system composed of business systems widely distributed geographically at all levels of generators and substations through close or loose connections. Its support environment includes not only the heterogeneous computer systems and local area networks of dispatching networks and power stations, but also the power system industry extranet connected to each local area network. Therefore, power information system security is different from pure computer system or communication system security. In order to ensure the security of power system business, it is necessary to consider the interaction between widely distributed and interconnected business systems and basic support systems such as computers and communications.
Photovoltaic secondary equipment prefabricated cabin
The secondary equipment prefabrication cabin is composed of prefabrication cabin, secondary equipment screen cabinet, secondary equipment and so on. The prefabricated cabin of the secondary equipment integrates the photovoltaic secondary equipment, and completes the related wiring between the screen cabinets in the prefabricated cabin, and transports it to the project site as a whole, and realizes the docking with the primary equipment and civil engineering on site. The combined secondary equipment of the prefabricated cabin is generally modularized according to the characteristics of the secondary system and the primary objects served.
other devices
-
The anti-islanding protection device
is mainly used for the islanding phenomenon caused by abnormal voltage or frequency in the photovoltaic power station, and predicts the occurrence of the phenomenon in advance, and quickly cuts off the grid-connected point switch, so that the photovoltaic power station and the grid are quickly separated. At the same time, it can play a role of intelligent grid connection. -
The power quality online monitoring device
mainly solves the power quality problems such as waveform distortion, voltage fluctuation and flicker, and three-phase unbalance due to the sharp increase of power load, especially the continuous growth of impact and nonlinear load capacity. -
The fault disconnecting device
is mainly used to monitor the voltage and current of the grid-connected point of power generation. When a fault occurs, the device makes logical judgments in time, reacts accurately, and quickly trips the grid-connected switch.