Do you understand these photovoltaic technical terms?
photovoltaic technical terms
Photovoltaic/photovoltaic effect
The full name is photovoltaic effect, which is the phenomenon that an object generates electromotive force due to the absorption of photons. When an object is exposed to light, the charge distribution state inside the object changes, producing an effect of electromotive force and current.
PV
A power generation technology that utilizes the photovoltaic effect to directly convert solar energy into electrical energy.
unit of measurement
Watt (W), kilowatt (kW), megawatt (MW), gigawatt (GW), terawatt (TW).
Calculation formula
1TW=1000GW=1000000MW=1000000000kW=1000000000000W.
unit of electrical energy
Kilowatt hour (kWh), that is, 1kWh of electrical energy is 1 kilowatt hour of electricity.
Inverter
One of the key equipments in the solar photovoltaic power generation system, its function is to convert the DC power emitted by the solar cells into AC power that meets the power quality requirements of the grid.
String inverter
The string inverter tracks several groups (usually 1-4 groups) of photovoltaic strings to individually track the maximum power peak, and then integrates them into the AC grid after inversion. A string inverter can have multiple maximum power peak tracking modules with relatively small power. It is mainly used in distributed power generation systems and centralized photovoltaic power generation systems.
Installed capacity
Solar cells can be packaged and protected after being connected in series to form a large-area solar cell module. Together with power controllers and other components, a photovoltaic power generation device is formed. The power generated by this device is the installed capacity.
Volume ratio
The ratio of the component capacity of the photovoltaic power station to the inverter capacity (capacity ratio = photovoltaic system installed capacity/photovoltaic system rated capacity).
Appropriately increasing the capacity-to-distribution ratio within a certain range can improve the utilization rate of other equipment, dilute investment costs, reduce construction costs and power generation costs. It can also make the output smoother and improve grid friendliness.
AGC
Automatic Generation Control (Automatic Generation Control), that is, the active power control system, responds to the remote adjustment instructions issued by the dispatcher and optimizes the calculation through the overall strategy of the AGC module to make the operating data meet the dispatching and grid connection requirements.
AVC
Automatic Voltage Control (Automatic Voltage Control), that is, reactive voltage regulation, quickly responds to dispatch instructions according to the grid voltage curve, automatically adjusts control strategies and response times such as reactive power and reactive power compensation devices, and achieves voltage regulation targets and reduces network losses. .
Photovoltaic power station low voltage ride-through technology
It means that when the voltage at the grid connection point of the photovoltaic power station fluctuates due to grid failure or disturbance, within a certain range, the photovoltaic power station can operate uninterruptedly on the grid.
average conversion efficiency
A measure of a solar cell’s ability to convert light energy into electrical energy. The optimal output power of a solar cell is the ratio of the solar radiation power projected onto its surface.
Levelized cost of electricity
Referred to as cost of electricity. The cost and power generation during the life cycle of the project are first levelized, and then the power generation cost is calculated, that is, the present value of the cost during the life cycle/the present value of power generation during the life cycle.
Affordable Internet access
It includes two meanings: power generation side parity and user side parity. Generation-side parity refers to the fact that photovoltaic power generation can achieve reasonable profits even if it is purchased according to the feed-in price of traditional energy (without subsidies); user-side parity refers to the fact that the cost of photovoltaic power generation is lower than the electricity sales price. According to the type of users and their electricity purchase costs, Different, it can be divided into industrial and commercial and residential user-side parity.
Benchmark on-grid electricity price
The National Development and Reform Commission sets the purchase price (tax included) for power grid companies to purchase electricity from centralized photovoltaic power stations connected to the grid.
Power generation equipment utilization hours
The number of operating hours of the average power generation equipment capacity in a region under full load operating conditions within a certain period, that is, the ratio of power generation to the average installed capacity, reflects the utilization rate of power generation equipment in the region. The formula is: utilization hours = power generation/installed capacity.
Yearly utilization hours
The average full-load operating time of the generating set within one year; among the 8,760 hours per year, the proportion of power generation equipment utilization hours is also called the “equipment utilization rate”.
Dedicated line access
Distributed power access points are equipped with switching equipment dedicated to distributed power, such as distributed power directly connected to substations, switching stations, power distribution room busbars, or ring network cabinets.
collector circuit
In a photovoltaic power generation system with decentralized inversion and centralized grid-connection, the electric energy output by each photovoltaic module string is combined to the inverter through the combiner box, and then collected to the power generation bus through the inverter output terminal. The DC and AC transmission lines are called collector circuit. The current collection line can be sent out by overhead, direct burial or bridge laying.
Combiner box
It can be divided into DC combiner box and AC combiner box. The DC combiner box is a wiring device that ensures the orderly connection and convergence function of photovoltaic modules; the AC combiner box combines the output currents of multiple inverters while protecting the inverters from harm from the AC grid-connected side/load. As an inverter The output disconnection point of the transformer improves the safety of the system and protects the safety of installation and maintenance personnel.
High, medium and low voltage grid connection of photovoltaic power plants
Generally, industrial and commercial projects of 400kW and below can be connected to the low-voltage 380V grid. Between 400kW and 2MW, multiple grid-connected points can be used for low-voltage grid connection. If it exceeds 2MW, it needs to be connected to the grid at 10kV. If it exceeds 6MW, it needs to be connected to the grid at 35kV (please refer to the local power grid company for details). requests or suggestions).
AC and DC cables
The power supply is divided into AC and DC, so it is divided into AC cable and DC cable. AC cables are used to connect AC power supply cables; DC cables are used to connect cables in DC power transmission and distribution systems.
Monocrystalline solar cells
A solar cell based on high-quality single crystal silicon materials and processing techniques, generally developed using technologies such as surface texturing, emitter area passivation, and zoned doping.
polycrystalline solar cells
Using solar-grade polysilicon material, the manufacturing process is similar to that of monocrystalline silicon solar cells. The current photoelectric conversion efficiency and production cost are slightly lower than monocrystalline solar cells.
Photovoltaic power plant low voltage ride through technology (Low Voltage Ride Through)
It means that when the voltage of the photovoltaic power station’s grid connection point fluctuates due to grid failure or disturbance, the photovoltaic power station can operate continuously on the grid within a certain range.