Goods and entertainment equipment. Such as remote areas in Northwest China in large scale use of photovoltaic systems of this type, load DC energy saving lamps, tape recorders and televisions, used to solve without electricity

 

    District, the family's basic lighting problems.

 

    The system features a simple DC system (Simple DC) is the system load DC load and the load time of use are no special requirements, the load is mainly used in the daytime, so the system does not make

 

    Batteries do not need to use the controller. The system is simple, direct use of solar energy solar modules to power the load, eliminating the losses caused by storage and release of energy in the battery

 

    , And the controller in the energy loss and improve the efficiency of utilization of solar energy. Commonly used in photovoltaic pumping systems, temporary equipment during the day electricity and tourist facilities. Figure 4-4 shows a simple straight

 

    The flow of photovoltaic pumping systems. Such systems in the developing areas of non-pure water for drinking has been widely used to produce a good social. 4.2.3 The large-scale solar-powered system

 

    (Large DC) compared with the two PV systems, this photovoltaic system will still apply to the DC power supply systems, this solar photovoltaic system load power to the load in order to ensure reliable mention

 

    For a stable electricity supply, the size of the system need to be equipped with solar solar module array and larger battery, often used in telecommunications, telemetry, monitoring equipment, power,

 

    Centralized power stations in rural areas, a lighted beacon, street lamps and other fields. "Bright Project" in China in the western region, some areas without electricity, the construction of photovoltaic power plants of some of the villages is to use this form;

 

    China Mobile and China Unicom is also used in remote power grid construction in communication base station PV systems supply AC and DC power supply (AC / DC) with the above three solar PV systems

 

    The difference is that the photovoltaic system to provide electricity for both DC and AC load the inverter in the system structure more than the above three systems, is used to convert DC to AC to meet the exchange of negative

 

    Set out the demand. Usually such a system load power consumption is relatively large, thus the size of the system. Communication base stations have both AC and DC load and the other containing AC and DC load

 

    Photovoltaic power plant. And DC (Utility, the Grid Connected) the biggest feature of this PV system is the solar modules is converted to meet the grid inverter

 

    Direct access to the public electricity grid requirements AC grid, grid-connected systems the PV array to generate electricity to supply the AC load, excess electricity back to the grid. In the rainy day or night, too

 

    The solar cell component does not generate electricity, or electricity generated can not meet the load demand from the mains supply. Directly to the electricity supply network, remove the battery configuration, eliminating the need for battery energy storage and release

 

    Process that can take full advantage of the power issued by the PV array to reduce energy loss and reduces the cost of the system. Dedicated grid-connected inverter system to ensure that the output power is full

 

    Foot grid electricity such as voltage, frequency electrical performance requirements. Because the efficiency of the inverter, there will still be part of the energy loss. This system is usually able to parallel the use of electricity and solar energy solar power

 

    Pool component array as a local AC load power, reducing the rate of the entire system load power shortage. And grid-connected PV systems can play a role in peak shaving to the utility grid. Grid-connected photovoltaic power supply system as a

 

    Distributed power generation systems, the traditional centralized power grid will have some adverse effects, such as harmonic pollution island effect. This solar photovoltaic hybrid power supply system (Hybrid)

 

    In addition to using solar energy solar module array system using the fuel generator as backup power. The purpose of using the hybrid power supply system to the comprehensive utilization of the advantages of various power generation technologies

 

    To avoid their disadvantages. For example, the advantages of the several stand-alone PV system is low maintenance, the disadvantage is that energy output is dependent on weather, unstable. The use of diesel generators and solar modules

 

    Energy provided by the hybrid power supply system and the independent system of a single energy dependent on the weather to be small, its advantages are: ? use of hybrid power supply system can reach the better renewable energy

 

    With. Because renewable energy is changing, unstable, so the system must be in accordance with energy at least a period of design. Because the system is designed in accordance with the worst-case scenario, so in the time

 

    , The system capacity is too large. Excess energy generated by the peak in solar irradiance can not use is wasted. Independent performance of the system as a whole is therefore reduced. If the worst month and

 

    Month difference, may lead to waste of energy equal to or even exceed the design load requirements. ? has a high system availability. Changes in the renewable energy and independent system

 

    Will cause the system to stable power supply can not meet the load demand is the load power shortage situation, the use of hybrid systems will greatly reduce the rate of load power shortage. ? and a single diesel power generation

 

    Machine system, compared with less maintenance and uses less fuel. ? high fuel efficiency. In the case of low load, the diesel engine's fuel efficiency is very low, will cause the waste of fuel.

 

    In a hybrid system can be integrated control makes the diesel engine near the rated power, thereby improving fuel efficiency. ? load to match better. The use of hybrid systems, because the diesel generator

 

    Offer instant access to the higher power, hybrid systems can be applied to a wider range of load system, for example, can use large AC load, impact load. You can also better match the load

 

    And systems for power generation, as long as the load during the peak period to open the reserve source of energy can be simple to do so. Sometimes, the size of the load determines the need to use a hybrid system, a large load requires a lot of current and very

 

    High voltage. If the only use of solar energy costs will be high. The hybrid system also has its own drawbacks: ? control is more complicated. Use a variety of energy, so the system need to be monitored every

 

    Kinds of energy work, to deal with the interaction between the various sub-energy systems, to coordinate the operation of the entire system, thus leading to the control system is more complex than stand-alone system, and now make more use of micro-processing chip into

 

    Line system management. ? the initial phase. Hybrid systems design, installation, construction project than an independent engineering. ? than stand-alone systems require more maintenance. Oil machine use is required

 

    To a lot of maintenance work, such as replacement of oil filter, fuel filter, spark plugs, etc., also need to add fuel to the tank. ? and noise pollution. PV system is no noise, no emissions

 

    Clean energy use, but because the use of a diesel hybrid systems, this will inevitably produce noise and pollution. In remote areas without electricity, communication power and civil aviation navigation equipment, power supply, because

 

    High power requirements, have adopted a hybrid system power supply, in order to achieve the best value for money. China's Xinjiang, Yunnan and the construction of rural photovoltaic power plants with light / diesel hybrid systems. And net mixed for

 

    With the development of solar photovoltaic industry, the electrical system (Hybrid), the emergence of hybrid power supply system can be comprehensive utilization of solar photovoltaic arrays, electricity and spare oil machine and network. This system is usually

 

    The integrated controller and inverter integration, the use of a computer chip full control over the operation of the system as a whole, comprehensive utilization of various energy sources, to achieve the best working conditions, and can be equipped with battery. Further

 

    Improve the load on the system power supply protection rate, such as AES, SMD inverter system. The system can provide qualified local load power, and can be used as an online UPS (uninterruptible power supply) work. It can be

 

    To the power grid, can also be obtained from the grid electricity, the bi-directional inverter / controller. The system works by electricity and photovoltaic power working in parallel, for the purposes of the local load, the solar modules

 

    Of electricity enough to load, it will directly use electricity generated by solar modules supply the load demand. If the electricity generated by solar modules over the immediate load demand but also the excess energy

 

    Return to the grid; If the electricity generated by the solar modules is not enough, it will automatically enable the mains electricity supply local load demand; Moreover, when the local load power consumption less than SMD inverter rated City

 

    60% of power capacity, the electricity will automatically charge to the battery, ensure that the battery long-term floating state; the mains failure, mains power failures or quality of electricity supply failure, the system

 

    Will automatically disconnect the mains, turn into a stand-alone mode, the load required by the battery and inverter to provide AC power. Once the electricity is back to normal, that is, voltage and frequency return to normal state within the system

 

    Will disconnect the battery instead of the grid mode, the mains power supply. System monitoring, control and data acquisition functions also some grid-connected hybrid power supply system can be integrated into the control chip.