CN201805238U - Intelligent control system for photovoltaic grid-connected power plant - Google Patents

Abstract

An intelligent control system for a photovoltaic grid-connected power plant comprises multiple groups of photovoltaic arrays, an inverter and a load, wherein the multiple groups of photovoltaic arrays are connected with an input side of the inverter. The intelligent control system is characterized by further comprising a first current transformer, a second current transformer and a plurality of direct-current contactors, a primary side of the first current transformer is connected with an output side of the inverter, a secondary side of the first current transformer is connected with an input end of a first current transmitter, an output end of the first current transmitter is connected with a central controller PLC, a primary side of the second current transformer is connected with a main input side of the load, a secondary side of the second current transformer is connected with an input end of a second current transmitter, an output end of the second current transmitter is connected with the central controller PLC, the direct-current contactors correspond to the photovoltaic arrays one by one, input ends of the direct-current contactors are correspondingly connected with a control signal output end of the central controller PLC through a control device, and the output end of each direct-current contactor is connected between the corresponding photovoltaic array and the input side of the inverter. The intelligent control system realizes detection and real-time control to photovoltaic power generation quantity, and prevents electric quantity from reversely flowing to an alternating-current power grid on the premise of meeting requirements of power utilization of the load when in power generation.

Description

The pv grid-connected plant intelligence control system

Technical field

The utility model relates to the photovoltaic plant technical field, specifically is a kind of pv grid-connected plant intelligence control system.

Background technology

Traditional fuel energy reduces day by day, and the harm that environment is caused also becomes increasingly conspicuous, and in order to keep long-range sustainable development, solar energy more and more comes into one's own as a kind of inexhaustible and free of contamination energy.Solar energy more and more is applied in life, industrial production, and photovoltaic generation is exactly wherein one.In field of photovoltaic power generation, there are two kinds of forms in the power station: a kind of is from net, i.e. solar panel power supply accumulators is then by the storage battery supply load; Also having a kind of is to be incorporated into the power networks, and is that photovoltaic generation and AC network are combined into load electric power is provided.And pv grid-connected plant is more and more at present, in order to realize that solar power system combines with intelligence between AC network, when making full use of solar power generation, prevent that adverse current from producing impact to AC network, electrical network not being had a negative impact becomes the technical problem that need overcome.

The utility model content

In order to overcome the shortcoming that above-mentioned prior art exists, the purpose of this utility model is to provide a kind of pv grid-connected plant intelligence control system, and it can prevent effectively that adverse current from producing impact to AC network.

For addressing the above problem, the utility model by the following technical solutions:

This pv grid-connected plant intelligence control system comprises many group photovoltaic arrays, inverter, load, organizes photovoltaic array more and is connected with the input side of described inverter, and the outlet side of inverter is connected with AC network;

Also comprise first current transformer, the primary side of described first current transformer is connected with the outlet side of described inverter, and secondary side connects the input of first current transducer; The output of described first current transducer connects first input end of analog signal of central controller PLC;

Also comprise second current transformer, the primary side of second current transformer connects total input side of load, and secondary side connects the input of second current transducer; The output of described second current transducer connects second input end of analog signal of described central controller PLC;

Also comprise a plurality of D.C. contactors, corresponding one by one with described photovoltaic array, the input of D.C. contactor is by the corresponding connection with the control signal output ends of described central controller PLC of control device, and the output of D.C. contactor is connected between the input side of corresponding photovoltaic array and described inverter.

Operation principle is as follows: utilize first current transformer to detect the outlet side electric current of inverter, and deliver to first input end of analog signal of central controller PLC after first current transducer is converted into first analog signal; Utilize second current transformer to detect the total input side electric current of load, and after second current transducer is converted into second analog signal, deliver to second input end of analog signal of described central controller PLC.Central controller PLC handles first analog signal, second analog signal that receive then, and judge relatively more corresponding photovoltaic generation amount with first analog signal, with the magnitude relationship of the corresponding load power consumption of second analog signal.Central controller PLC is according to the judged result of the magnitude relationship of described photovoltaic generation amount, load power consumption, and output is to the control signal of described D.C. contactor.If when judging the solar power generation amount less than the load power consumption, central controller PLC controls all D.C. contactor closures, starts all photovoltaic arrays.If when judging the solar power generation amount greater than the load power consumption, central controller PLC controls one or more D.C. contactors and opens according to the size output control signal of difference, closes one or more groups photovoltaic array.

The beneficial effects of the utility model are: can realize the detection of photovoltaic generation amount and control in real time, satisfy under the prerequisite that load uses in generating and to prevent the electric weight adverse current to the situation that exchanges electrical network, solve the problem that exists when combining between solar power generation and the AC network, for the application of solar power generation provides convenience, photovoltaic generation universal played great facilitation.

Description of drawings

Below in conjunction with drawings and Examples the utility model is described further:

Fig. 1 is the circuit theory diagrams of the utility model embodiment,

Fig. 2 is the schematic block circuit diagram of the utility model embodiment,

Among the figure: 1 photovoltaic array, 2 inverters, 3 first current transducers, 4 central controller PLC, 5 loads, 6 second current transducers, 7 AC network, 8 D.C. contactors, 9 control device.

Embodiment

As shown in Figure 1, 2, this pv grid-connected plant intelligence control system comprises many group photovoltaic arrays 1, inverter 2, load 5, organizes photovoltaic array 1 more and is connected with the input side of described inverter 2, and the outlet side of inverter 2 is connected with AC network 7; Also comprise the first current transformer TA1, first current transducer 3, central controller PLC 4, the second current transformer TA2, second current transducer 6 and a plurality of D.C. contactor 8.

The primary side of the first current transformer TA1 is connected with the outlet side of described inverter 2, and secondary side connects the input of first current transducer 3; The output of described first current transducer 3 connects first input end of analog signal of central controller PLC 4.

The primary side of the second current transformer TA2 connects total input side of load 5, and secondary side connects the input of second current transducer 6; The output of described second current transducer 6 connects second input end of analog signal of described central controller PLC 4.

Each D.C. contactor 8 is corresponding one by one with every group of photovoltaic array 1, the input of D.C. contactor 8 is by the corresponding connection with the control signal output ends of described central controller PLC 4 of control device 9, and the output of D.C. contactor 8 is connected between the input side of corresponding photovoltaic array and described inverter 2.

Its operation principle is as follows: utilize the first current transformer TA1 to detect the outlet side electric current of inverter 2, and be converted into first input end of analog signal of delivering to central controller PLC 4 after first analog signal of 4-20mA through first current transducer 3.Utilize the second current transformer TA2 to detect load 5 total input side electric currents, and be converted into second input end of analog signal of delivering to described central controller PLC 4 after second analog signal of 4-20mA through second current transducer 6.

Then, first analog signal, second analog signal that 4 couples of central controller PLC receive are handled, and judge relatively more corresponding photovoltaic generation amount with first analog signal, with the magnitude relationship of the corresponding load power consumption of second analog signal, and according to the judged result of the magnitude relationship of described photovoltaic generation amount, load power consumption, output is to the control signal of described D.C. contactor.

If when judging the photovoltaic generation amount less than the load power consumption, central controller PLC controls all D.C. contactor closures, starts all photovoltaic arrays.

If when judging the photovoltaic generation amount greater than the load power consumption, central controller PLC controls one or more D.C. contactors and opens according to the size output control signal of difference, closes one or more groups photovoltaic array.For example: when the photovoltaic generation amount surpass the load power consumption 105% the time, open a D.C. contactor, close one group of photovoltaic array to reduce the solar power generation amount; And the like.Central controller PLC according to the size of described difference, adjusts the quantity of opening D.C. contactor in real time, promptly adjusts the group number of closing photovoltaic array.

Like this in pv grid-connected plant work:

When photovoltaic array does not generate electricity, power to the load by AC network;

The electric weight that sends when photovoltaic array does not satisfy load when using, and provides required electric weight to load jointly by photovoltaic array and AC network;

When the electric weight that sends when photovoltaic array surpasses the use amount of load, can cut off single output of organizing or organizing photovoltaic array more by force as required, to reduce the output electric weight of photovoltaic generating system, make it to be complementary with the power consumption of load, prevent the photovoltaic generation surplus and adverse current to the situation that exchanges electrical network.

Claims (1)

1. the pv grid-connected plant intelligence control system comprises many group photovoltaic arrays, inverter, load, organizes photovoltaic array more and is connected with the input side of described inverter, and the outlet side of inverter is connected with AC network; It is characterized in that:

Also comprise first current transformer, the primary side of described first current transformer is connected with the outlet side of described inverter, and secondary side connects the input of first current transducer; The output of described first current transducer connects first input end of analog signal of central controller PLC;

Also comprise second current transformer, the primary side of second current transformer connects total input side of load, and secondary side connects the input of second current transducer; The output of described second current transducer connects second input end of analog signal of described central controller PLC;

Also comprise a plurality of D.C. contactors, corresponding one by one with described photovoltaic array, the input of D.C. contactor is by the corresponding connection with the control signal output ends of described central controller PLC of control device, and the output of D.C. contactor is connected between the input side of corresponding photovoltaic array and described inverter.

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