Metering acquisition circuit applied to photovoltaic grid-connected system and photovoltaic grid-connected system

Abstract

The utility model discloses a metering acquisition circuit applied to a photovoltaic grid-connected system and the photovoltaic grid-connected system, and relates to the technical field of photovoltaic grid-connected power generation, the metering acquisition circuit comprises an electricity meter, an acquisition module and a master control module, the electricity meter is used for acquiring voltage and current of a mains supply grid-connected module; the acquisition module is used for acquiring the voltage and current of the generator grid-connected module and acquiring the voltage and current of the photovoltaic inversion grid-connected module; and the main control module is in communication connection with the acquisition module and the electric meter and is used for acquiring the voltage data and the current data sent by the commercial power grid-connected module and acquiring the voltage data and the current data sent by the acquisition module. And the volume of the box body where the circuit is located can be reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to photovoltaic grid-connected power generation technical field especially relates to a kind of metering acquisition circuit and photovoltaic grid-connected system applied to photovoltaic grid-connected system. BACKGROUND

[0002] In the power supply system of gateway, three ways of photovoltaic power generation, generator power supply and mains power supply are usually used to provide stable energy supply to the load end of circuit in power supply system, in order to ensure the stability and reliability of power supply of each power supply side, the electric meter is arranged at the first phase input end and the second phase input end of generator side, photovoltaic side and mains side respectively, the voltage and current of each power supply side are monitored through the electric meter, the abnormal situation in power supply can be found in time, so that measures are taken quickly to ensure the stable operation of circuit, but through the electric meter arranged at the first phase input end and the second phase input end of three power supply sides to collect voltage and current, not only increases the cost of overall circuit, reduces the space of circuit debugging and optimization, but also increases the size of the box where the circuit is located. SUMMARY

[0003] The utility model discloses a kind of metering acquisition circuit and photovoltaic grid-connected system applied to photovoltaic grid-connected system, to reduce electric meter use, reduce cost and reduce the volume of the box where the circuit is located, to at least solve one of the technical problems existing in the prior art.

[0004] In the first aspect, the utility model embodiment provides a kind of metering acquisition circuit applied to photovoltaic grid-connected system, and the photovoltaic grid-connected system includes grid-connected bus, photovoltaic inverter grid-connected module, generator grid-connected module and mains grid-connected module, the photovoltaic inverter grid-connected module, the generator grid-connected module and the mains grid-connected module are connected with the grid-connected bus, and the metering acquisition circuit includes: electric meter, acquisition module and main control module, the electric meter is used to collect the voltage and current of the mains grid-connected module;The acquisition module is used to collect the voltage and current of the generator grid-connected module, and collect the voltage and current of the photovoltaic inverter grid-connected module;The main control module is respectively connected with the acquisition module and the electric meter communication, for obtaining the voltage data and current data sent by the mains grid-connected module, and obtaining the voltage data and current data sent by the acquisition module.

[0005] The utility model discloses a measurement collection circuit applied to photovoltaic grid-connected system, at least has following beneficial effect: through the acquisition module gathers the current and voltage of photovoltaic inverter grid-connected module and gathers the current and voltage of generator grid-connected module, through the electric meter gathers the current and voltage of mains grid-connected module, and the acquisition module and electric meter are connected respectively with main control module, obtains the current data and voltage data of acquisition module transmission and is used for obtaining the current data and voltage data of electric meter transmission, can real -time monitoring to each power supply side's voltage and current condition, thereby takes the measure to ensure the stable operation of circuit quickly, compared with using multiple electric meters respectively in photovoltaic inverter grid-connected module and generator grid-connected module gathers the current and voltage scheme, uses the acquisition module in photovoltaic inverter grid-connected module and generator grid-connected module gathers the current and voltage scheme not only reduces the cost, but also reduces the area of measurement collection circuit in the box that it is at in its place, increases the space of circuit debugging and optimization, also is favorable to reducing the manufacturing size of its place box, further saves production cost.

[0006] According to some embodiments of the utility model provide measurement collection circuit, the acquisition module includes first acquisition unit and second acquisition unit, first acquisition unit is used to gather the current and voltage of photovoltaic inverter grid-connected module, second acquisition unit is used to gather the current and voltage of generator grid-connected module.

[0007] According to some embodiments of the utility model provide measurement collection circuit, first acquisition unit includes first voltage sensor, first current sensor and first measurement unit, first measurement unit is connected with first voltage sensor, first current sensor and main control module respectively, first voltage sensor is used to gather the voltage of photovoltaic inverter grid-connected module, and first current sensor is used to gather the current of photovoltaic inverter grid-connected module.

[0008] According to some embodiments of the utility model provide measurement collection circuit, second acquisition unit includes second voltage sensor, second current sensor and second measurement unit, second measurement unit is connected with second voltage sensor, second current sensor and main control module respectively, second voltage sensor is used to gather the voltage of generator grid-connected module, and second current sensor is used to gather the current of generator grid-connected module.

[0009] According to some embodiments of the utility model provide measurement collection circuit, first measurement unit and main control module are connected using TTL communication mode.

[0010] According to some embodiments of the utility model provide measurement collection circuit, second measurement unit and main control module are connected using TTL communication mode.

[0011] The ammeter and the main control module are connected in an RS485 communication mode.

[0012] In the second aspect, the utility model embodiment provides a kind of photovoltaic grid-connected system, including grid-connected busbar, photovoltaic inverter grid-connected module, generator grid-connected module, mains grid-connected module and the metering acquisition circuit of any one described in the first aspect embodiment, the photovoltaic inverter grid-connected module, the generator grid-connected module and the mains grid-connected module are all connected with the grid-connected busbar.

[0013] According to some embodiments of the utility model provide photovoltaic grid-connected system, output line in the mains grid-connected module is sequentially provided with first circuit breaker and first relay, and the ammeter is used to collect the voltage and current of line section between the first circuit breaker and the first relay.

[0014] According to some embodiments of the utility model provide photovoltaic grid-connected system, output line in the generator grid-connected module is sequentially provided with second circuit breaker and second relay, and the acquisition module is used to collect the voltage and current of line section between the second circuit breaker and the second relay.

[0015] According to some embodiments of the utility model provide photovoltaic grid-connected system, output line in the photovoltaic inverter grid-connected module is sequentially provided with third circuit breaker and third relay, and the acquisition module is used to collect the voltage and current of line section after the third relay. BRIEF DESCRIPTION OF DRAWINGS

[0016] The accompanying drawings are used to provide further understanding of the technical scheme of the utility model, and constitute a part of the specification, and are used to explain the technical scheme of the utility model together with the embodiments of the utility model, and do not constitute the limitation to the technical scheme of the utility model.

[0017] The utility model is further illustrated as follows by combining with the drawings and embodiments;

[0018] Figure 1 It is the relay topology and circuit breaker topology structure diagram of photovoltaic grid-connected system provided in the utility model embodiment;

[0019] Figure 2 It is the system block diagram of metering acquisition circuit applied to photovoltaic grid-connected system provided in the utility model embodiment. DETAILED DESCRIPTION

[0020] The detailed embodiments of the present application will be described in this section, and the preferred embodiments of the present application are shown in the drawings, the role of the drawings is to supplement the description of the text part with graphics, so that people can intuitively and visually understand each technical feature and the overall technical scheme of the present application, but it cannot be understood as a limitation on the protection scope of the present application.

[0021] In the description of the present application, if the first and second are described for the purpose of distinguishing technical features, they cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or implicitly indicating the order of indicated technical features.

[0022] In the description of the present application, unless otherwise explicitly limited, the words such as setting, installing and connecting should be broadly understood, and the skilled in the art can reasonably determine the specific meaning of the above words in the present application in combination with the specific content of the technical scheme.

[0023] Reference Figure 1In the photovoltaic grid-connected system, three ways of photovoltaic power generation, generator power supply and mains power supply are used to provide stable energy supply to the load end of the circuit, and the power supply system includes a grid-connected bus 1100, a photovoltaic inverter grid-connected module 1200, a generator grid-connected module 1300, a mains grid-connected module 1400, a first energy storage inverter grid-connected module 1500, a second energy storage inverter grid-connected module 1600, a first intelligent load grid-connected module 1700, a second intelligent load grid-connected module 1800, a third intelligent load grid-connected module 1900, and a load end powered by the photovoltaic inverter grid-connected module 1200, the generator grid-connected module 1300 and the mains grid-connected module 1400. The photovoltaic inverter grid-connected module 1200, the generator grid-connected module 1300, the mains grid-connected module 1400, the first energy storage inverter grid-connected module, the second energy storage inverter grid-connected module, the first intelligent load grid-connected module 1700, the second intelligent load grid-connected module 1800, the third intelligent load grid-connected module 1900 and the load end are all connected with the grid-connected bus 1100. Specifically, the first phase input end L1 and the second phase input end L2 of the mains grid-connected module 1400 are connected with a first circuit breaker QF1 and a first relay RY1 in sequence; the first phase input end L1 and the second phase input end L2 of the generator grid-connected module 1300 are connected with a second circuit breaker QF2 and a second relay RY2 in sequence; the first phase input end L1 and the second phase input end L2 of the photovoltaic inverter grid-connected module 1200 are connected with a third circuit breaker QF3, and the first phase input end L1 is further connected with a third relay RY3 which is connected after the third circuit breaker QF3; the first phase input end L1 and the second phase input end L2 of the first energy storage inverter grid-connected module 1500 are connected with a fourth circuit breaker QF4; the first phase input end L1 and the second phase input end L2 of the second energy storage inverter grid-connected module 1600 are connected with a fifth circuit breaker QF5; the first phase input end L1 and the second phase input end L2 of the first intelligent load grid-connected module 1700 are connected with a sixth circuit breaker QF6 in sequence, and the first phase input end L1 is further connected with a fourth relay RY4 which is connected after the sixth circuit breaker QF6, and the second phase input end L2 is further connected with a fifth relay RY5 which is connected after the sixth circuit breaker QF6; the first phase input end L1 and the second phase input end L2 of the second intelligent load grid-connected module 1800 are connected with a seventh circuit breaker QF7 in sequence, and the first phase input end L1 is further connected with a sixth relay RY6 which is connected after the seventh circuit breaker QF7, and the second phase input end L2 is further connected with a seventh relay RY7 which is connected after the seventh circuit breaker QF7.The eighth circuit breaker QF8 is connected in sequence to the first phase input end L1 and the second phase input end L2 of the third intelligent load grid-connected module 1900, the eighth relay RY8 is further connected to the first phase input end L1, and the eighth relay RY8 is connected after the eighth circuit breaker QF8; and the ninth relay RY9 is further connected to the second phase input end L2, and the ninth relay RY9 is connected after the eighth circuit breaker QF8.

[0024] In order to ensure the stability and reliability of power supply of each power supply side, the electric meter is arranged in the mains grid-connected module 1400 to collect the voltage and current of the line section between the first circuit breaker QF1 and the first relay RY1, that is, to collect the voltage and current at the TA1 and TA2 positions; the electric meter is arranged in the generator grid-connected module 1300 to collect the voltage and current of the line section between the second circuit breaker QF2 and the second relay RY2, that is, to collect the voltage and current at the TA3 and TA4 positions; the electric meter is arranged in the photovoltaic inverter grid-connected module 1200 to collect the voltage and current of the line section after the third relay RY3, that is, to collect the voltage and current at the TA5 position; and the electric meter is also arranged after the third circuit breaker QF3 connected to the second phase input end L2 of the photovoltaic inverter grid-connected module 1200 to collect the voltage and current at the TA6 position; by arranging the electric meters at the first phase input end L1 and the second phase input end L2 of the generator side, the photovoltaic side and the mains side respectively, the voltage and current of each power supply side can be monitored by the electric meters, so that abnormal conditions in power supply can be found in time, and measures can be taken to ensure the stable operation of the circuit, for example, when it is detected that the current or voltage of a power supply side exceeds a preset value, the relay is disconnected, and the power supply of the load end by the power supply side is stopped.

[0025] Although the voltage and current can be collected by arranging the electric meters at the first phase input end L1 and the second phase input end L2 of the three power supply sides, that is, the photovoltaic inverter grid-connected module 1200, the generator grid-connected module 1300 and the mains grid-connected module 1400, abnormal conditions in power supply can be found in time, and measures can be taken to ensure the stable operation of the circuit, the electric meters are large in size and high in cost, which not only increases the cost of the overall circuit, reduces the space for debugging and optimization of the circuit, but also increases the size of the box in which the circuit is located.

[0026] Based on this, the utility model embodiment provides a metering and collecting circuit applied to a photovoltaic grid-connected system and a photovoltaic grid-connected system, which can reduce the use of electric meters, reduce the cost and reduce the size of the box in which the circuit is located.

[0027] The utility model embodiments are further described below with reference to the drawings.

[0028] Reference Figure 2The utility model discloses a kind of metering acquisition circuits applied to photovoltaic grid-connected system, photovoltaic grid-connected system includes grid-connected bus 1100, photovoltaic inverter grid-connected module 1200, generator grid-connected module 1300 and mains grid-connected module 1400, photovoltaic inverter grid-connected module 1200, generator grid-connected module 1300 and mains grid-connected module 1400 are connected with grid-connected bus 1100, metering acquisition circuit includes: electric meter 2100, acquisition module 2200 and main control module 2300, electric meter 2100 is used to acquire the voltage and current of mains grid-connected module 1400;Acquisition module 2200 is used to acquire the voltage and current of generator grid-connected module 1300, and acquisition photovoltaic inverter grid-connected module 1200's voltage and current;Main control module 2300 is connected with acquisition module 2200 and electric meter 2100 communication respectively, for obtaining the voltage data and current data sent by mains grid-connected module 1400, and obtaining the voltage data and current data sent by acquisition module 2200.

[0029] According to the utility model embodiment provided application in photovoltaic grid-connected system's metering acquisition circuit, through acquisition module 2200 acquisition photovoltaic inverter grid-connected module 1200's current and voltage and acquisition generator grid-connected module 1300's current and voltage, through electric meter 2100 acquisition mains grid-connected module 1400's current and voltage, main control module 2300 is connected with acquisition module 2200 and electric meter 2100 respectively, obtains the current data and voltage data sent by acquisition module 2200 and is used to obtain the current data and voltage data sent by electric meter 2100, can be monitored to each power supply side's voltage and current condition in real time, to ensure the stable operation of circuit rapidly takes measures, compared with using multiple electric meters 2100 respectively in photovoltaic inverter grid-connected module 1200 and generator grid-connected module 1300 acquisition current and voltage scheme, using acquisition module 2200 in photovoltaic inverter grid-connected module 1200 and generator grid-connected module 1300 acquisition current and voltage scheme not only reduces cost, also reduces the area of metering acquisition circuit in the box where it is located, increase the space of circuit debugging and optimization, also be favorable to reduce the manufacturing size of the box where it is located, further save production cost.

[0030] According to some embodiments of the utility model provide metering acquisition circuit, acquisition module 2200 includes first acquisition unit 2210 and second acquisition unit 2220, first acquisition unit 2210 is used to acquire the current and voltage of photovoltaic inverter grid-connected module 1200, and second acquisition unit 2220 is used to acquire the current and voltage of generator grid-connected module 1300.

[0031] It can be understood that the acquisition module 2200 is composed of the first acquisition unit 2210 and the second acquisition unit 2220 which are separately arranged, and the sampling circuit is carried through the separate device, so that the first acquisition unit 2210 and the second acquisition unit 2220 can be more flexibly arranged according to the physical positions of the photovoltaic inverter grid-connected module 1200 and the generator grid-connected module 1300; in addition, each acquisition unit is independent, and when one of the acquisition units fails, the normal work of the other acquisition units will not be affected, thereby improving the stability of the metering acquisition circuit.

[0032] According to the metering acquisition circuit provided by some embodiments of the utility model, the first acquisition unit 2210 includes a first voltage sensor 2211, a first current sensor 2212 and a first metering unit 2213, the first metering unit 2213 is connected with the first voltage sensor 2211, the first current sensor 2212 and the master control module 2300 respectively, the first voltage sensor 2211 is used for acquiring the voltage of the photovoltaic inverter grid-connected module 1200, and the first current sensor 2212 is used for acquiring the current of the photovoltaic inverter grid-connected module 1200.

[0033] It should be noted that the first acquisition unit 2210 is arranged in the first phase input end L1 and the second phase input end L2 of the photovoltaic inverter grid-connected module 1200, that is, two first current sensors 2212, two first current sensors 2212 and two first metering units 2213 are arranged in the photovoltaic inverter grid-connected module 1200, wherein the first current sensor 2212 is annular, the two first current sensors 2212 are respectively sleeved in the acquisition positions of the lines connected with the first phase input end L1 and the second phase input end L2 in the photovoltaic inverter grid-connected module 1200, so as to acquire the current of the photovoltaic inverter grid-connected module 1200; and one access point is led out at the acquisition position of the line connected with the first phase input end L1 and the acquisition position of the line connected with the second phase input end L2 in the photovoltaic inverter grid-connected module 1200, and the two first voltage sensing modules are respectively connected with the access points, so as to acquire the voltage of the photovoltaic inverter grid-connected module 1200.

[0034] It can be understood that the first metering unit 2213 is a metering chip, the first metering unit 2213 can transmit the voltage data acquired by the first voltage sensor 2211 and the current data acquired by the first current sensor 2212 to the master control module 2300, or the first metering unit 2213 converts the voltage data acquired by the first voltage sensor 2211 and the current data acquired by the first current sensor 2212 into power data and transmits the power data to the master control module 2300.

[0035] The metering acquisition circuit according to some embodiments of the utility model provides, second acquisition unit 2220 includes second voltage sensor 2221, second current sensor 2222 and second metering unit 2223, second metering unit 2223 is connected with second voltage sensor 2221, second current sensor 2222 and main control module 2300 respectively, second voltage sensor 2221 is used to collect the voltage of generator grid-connected module 1300, and second current sensor 2222 is used to collect the current of generator grid-connected module 1300.

[0036] It needs to be explained that, the first phase input end L1 in generator grid-connected module 1300, second phase input end L2 are provided with first acquisition unit 2210, namely, two second current sensors 2222 and two second current sensors 2222 and two second metering units 2223 are arranged in generator grid-connected module 1300, wherein, second current sensor 2222 is annular, two second current sensors 2222 are respectively sleeved in the collection position of the circuit of first phase input end L1 in generator grid-connected module 1300 and the collection position of the circuit of second phase input end L2, realize the current of generator grid-connected module 1300 is collected;And the collection position of the circuit of first phase input end L1 in generator grid-connected module 1300 and the collection position of the circuit of second phase input end L2 each lead out an access point, two first voltage sensing modules are respectively connected to the access point, realize the voltage of generator grid-connected module 1300 is collected.

[0037] It can be understood that, second metering unit 2223 is a metering chip, and second metering unit 2223 can transmit the voltage data collected by second voltage sensor 2221 and the current data collected by second current sensor 2222 to main control module 2300, or second metering unit 2223 converts the voltage data collected by second voltage sensor 2221 and the current data collected by second current sensor 2222 into power data and transmits the power data to main control module 2300.

[0038] The metering acquisition circuit according to some embodiments of the utility model provides, first metering unit 2213 and main control module 2300 are connected in TTL communication mode.

[0039] It can be understood that, in the metering acquisition circuit, TTL communication mode is used to realize the communication between first metering unit 2213 and main control module 2300, which not only has faster data transmission speed and lower power consumption, but also saves cost.

[0040] The metering acquisition circuit according to some embodiments of the utility model provides, second metering unit 2223 and main control module 2300 are connected in TTL communication mode.

[0041] It can be understood that the TTL communication mode is used in the meter acquisition circuit to realize the communication between the second metering unit 2223 and the main control module 2300, which is not only faster in data transmission speed and lower in power consumption, but also saves cost.

[0042] According to the meter acquisition circuit provided by some embodiments of the utility model, the electric meter 2100 and the main control module 2300 are connected in an RS485 communication mode.

[0043] It can be understood that the RS485 communication mode is used in the meter acquisition circuit to realize the communication between the electric meter 2100 and the main control module 2300, which not only reduces the number and complexity of the communication lines and reduces the overall cost of the system, but also realizes long-distance communication and can more flexibly adjust the position distance between the electric meter 2100 and the control module.

[0044] In the second aspect, the utility model embodiment provides a photovoltaic grid-connected system, including grid-connected bus 1100, photovoltaic inverter grid-connected module 1200, generator grid-connected module 1300, mains grid-connected module 1400 and the meter acquisition circuit of any one in the first aspect embodiment, photovoltaic inverter grid-connected module 1200, generator grid-connected module 1300 and mains grid-connected module 1400 all are connected with grid-connected bus 1100.

[0045] It can be understood that the electric meter 2100 in the meter acquisition circuit is used to acquire the voltage and current of the mains grid-connected module 1400, the acquisition module 2200 is used to acquire the voltage and current of the generator grid-connected module 1300 and the photovoltaic inverter grid-connected module 1200, the main control module 2300 acquires the current data and voltage data sent by the acquisition module 2200 and is used to acquire the current data and voltage data sent by the electric meter 2100, the main control module 2300 compares the current data and voltage data with preset data, can timely find the abnormal situation in power supply, and thus rapidly takes measures to ensure the stable operation of the photovoltaic grid-connected system.

[0046] According to the photovoltaic grid-connected system provided by some embodiments of the utility model, the output line in the mains grid-connected module 1400 is sequentially provided with a first circuit breaker QF1 and a first relay RY1, and the electric meter 2100 is used to acquire the voltage and current of the line section between the first circuit breaker QF1 and the first relay RY1.

[0047] It can be understood that the electric meter 2100 is used to acquire the voltage and current at TA1 and TA2 positions in the line section between the first circuit breaker QF1 and the first relay RY1, the main control module 2300 is in communication connection with the electric meter 2100, the main control module 2300 compares the acquired current data and voltage data with preset data, can timely find the abnormal situation in power supply, and thus rapidly takes measures to ensure the stable operation of the photovoltaic grid-connected system.

[0048] It can be understood that the master module 2300 is connected with the electric meter 2100 in the grid-connected module 1400, receives the current and voltage of the grid-connected module 1400 collected by the electric meter 2100, and when overcurrent or overvoltage of the grid-connected module 1400 is detected, in order to ensure the stable operation of the circuit, the first relay RY1 is controlled to be disconnected to stop the grid-connected module 1400 from supplying power to the load end of the load; or the master module 2300 sends an alarm prompt, so as to remind the staff to manually disconnect the first circuit breaker QF1 to stop the grid-connected module 1400 from supplying power to the load end of the load.

[0049] According to the photovoltaic grid-connected system provided by some embodiments of the utility model, the load end comprises an important load module and a common load module, the important load module is connected with the grid-connected bus 1100, and the common load is connected with the line section between the first circuit breaker QF1 and the first relay RY1.

[0050] It can be understood that when overcurrent or overvoltage of the grid-connected module 1400 is detected, in order to ensure the stable operation of the circuit, the first relay RY1 is controlled to be disconnected to stop the grid-connected module 1400 from supplying power to the important load of the load end; or the master module 2300 sends an alarm prompt, so as to remind the staff to manually disconnect the first circuit breaker QF1 to stop the grid-connected module 1400 from supplying power to the common load and the important load of the load end; in addition, since the important load is connected with the grid-connected bus 1100, the grid-connected module 1400, the photovoltaic inverter grid-connected module 1200 and the generator grid-connected module 1300 all supply power to the important load, when overcurrent or overvoltage of the grid-connected module 1400 is detected, the photovoltaic inverter grid-connected module 1200 and the generator grid-connected module 1300 can still supply power to the important load module, which further enhances the stability of the operation of the photovoltaic grid-connected system.

[0051] According to the photovoltaic grid-connected system provided by some embodiments of the utility model, the output line in the generator grid-connected module 1300 is sequentially provided with the second circuit breaker QF2 and the second relay RY2, and the acquisition module 2200 is used for acquiring the voltage and current of the line section between the second circuit breaker QF2 and the second relay RY2.

[0052] It should be noted that the acquisition module 2200 is configured to acquire the voltage and current at the TA3 and TA4 positions in the line segment between the second circuit breaker QF2 and the second relay RY2, the main control module 2300 acquires the current data and voltage data sent by the acquisition module 2200, and the main control module 2300 is configured to compare the current data and the voltage data with preset data, so that abnormal conditions in power supply can be found in time, and measures can be taken to ensure the stable operation of the photovoltaic grid-connected system.

[0053] It can be understood that the main control module 2300 is connected with the acquisition module 2200 and receives the current and voltage of the generator grid-connected module 1300 acquired by the acquisition module 2200, and when overcurrent or overvoltage of the current and voltage of the generator grid-connected module 1300 is detected, the second relay RY2 is controlled to be disconnected to stop the generator grid-connected module 1300 from supplying power to the load end; or the main control module 2300 sends an alarm prompt to remind the staff to manually disconnect the second circuit breaker QF2 to stop the generator grid-connected module 1300 from supplying power to the load end.

[0054] According to the photovoltaic grid-connected system provided by some embodiments of the utility model, the output line in the generator grid-connected module 1300 is sequentially provided with the second circuit breaker QF2 and the second relay RY2, and the second acquisition unit 2220 is configured to acquire the voltage and current of the line segment between the second circuit breaker QF2 and the second relay RY2.

[0055] It should be noted that the second acquisition unit 2220 includes a second voltage sensor 2221, a second current sensor 2222, and a second metering unit 2223, the second metering unit 2223 is connected with the second voltage sensor 2221, the second current sensor 2222, and the main control module 2300, respectively, the second voltage sensor 2221 is configured to acquire the voltage of the line segment between the second circuit breaker QF2 and the second relay RY2, and the second current sensor 2222 is configured to acquire the current of the line segment between the second circuit breaker QF2 and the second relay RY2.

[0056] According to the photovoltaic grid-connected system provided by some embodiments of the utility model, the output line in the photovoltaic inverter grid-connected module 1200 is sequentially provided with the third circuit breaker QF3 and the third relay RY3, and the acquisition module 2200 is configured to acquire the voltage and current of the line segment after the third relay RY3.

[0057] It should be noted that the light-voltage inverter grid-connected module 1200 is provided with the acquisition module 2200 for acquiring the voltage and current of the line section after the third relay RY3, that is, the voltage and current at the TA5 position, and the acquisition module 2200 is also provided after the third circuit breaker QF3 connected to the second phase input end L2 of the light-voltage inverter grid-connected module 1200, and the acquisition module 2200 is used for acquiring the voltage and current at the TA6 position. The main control module 2300 acquires the current data and voltage data sent by the acquisition module 2200, and the main control module 2300 can timely find abnormal conditions in power supply by comparing the current data and voltage data with preset data, so as to take measures to ensure the stable operation of the light-voltage grid-connected system.

[0058] It can be understood that the main control module 2300 is connected with the acquisition module 2200 and receives the current and voltage of the light-voltage inverter grid-connected module 1200 collected by the acquisition module 2200. When it is detected that the current and voltage of the light-voltage inverter grid-connected module 1200 appear overcurrent or overvoltage, in order to ensure the stable operation of the circuit, the third relay RY3 is controlled to be disconnected to stop the light-voltage inverter grid-connected module 1200 from supplying power to the load end of the load; or the main control module 2300 sends an alarm prompt, so as to remind the staff to manually disconnect the third circuit breaker QF3 to stop the light-voltage inverter grid-connected module 1200 from supplying power to the load end of the load.

[0059] According to the light-voltage grid-connected system provided by some embodiments of the utility model, the output line in the light-voltage inverter grid-connected module 1200 is sequentially provided with the third circuit breaker QF3 and the third relay RY3, and the first acquisition unit 2210 is used for acquiring the voltage and current of the line section after the third relay RY3.

[0060] It should be noted that the first phase input end L1 and the second phase input end L2 in the light-voltage inverter grid-connected module 1200 are each provided with a first acquisition unit 2210, the first acquisition unit 2210 includes a first voltage sensor 2211, a first current sensor 2212 and a first metering unit 2213, and the first metering unit 2213 is connected with the first voltage sensor 2211, the first current sensor 2212 and the main control module 2300 respectively; at the first phase input end L1, the first voltage sensor 2211 is used for acquiring the voltage of the line section after the third relay RY3, and the first current sensor 2212 is used for acquiring the current of the line section after the third relay RY3; and another first acquisition unit 2210 is provided after the third circuit breaker QF3 connected to the second phase input end L2.

[0061] The utility model embodiment makes the detailed explanation in combination with the drawing, but the utility model is not limited to the above -mentioned embodiment, still can make various changes in the knowledge range of ordinary skill in the art who has in the premise of not departing from the utility model purpose.

Claims

1. A metering acquisition circuit applied to a photovoltaic grid-connected system, characterized in that, The photovoltaic grid-connected system comprises a grid-connected bus, a photovoltaic inverter grid-connected module, a generator grid-connected module and a mains grid-connected module, the photovoltaic inverter grid-connected module, the generator grid-connected module and the mains grid-connected module are connected with the grid-connected bus, and the metering and collecting circuit comprises: an electric meter for collecting voltage and current of the mains grid-connected module; a collecting module for collecting voltage and current of the generator grid-connected module and collecting voltage and current of the photovoltaic inverter grid-connected module; a master control module in communication connection with the collecting module and the electric meter respectively, for acquiring voltage data and current data sent by the mains grid-connected module and acquiring voltage data and current data sent by the collecting module.

2. The metrology harvesting circuit of claim 1, wherein, The collecting module comprises a first collecting unit and a second collecting unit, the first collecting unit is used for collecting current and voltage of the photovoltaic inverter grid-connected module, and the second collecting unit is used for collecting current and voltage of the generator grid-connected module.

3. The metrology harvesting circuit of claim 2, wherein, The first collecting unit comprises a first voltage sensor, a first current sensor and a first metering unit, the first metering unit is connected with the first voltage sensor, the first current sensor and the master control module respectively, the first voltage sensor is used for collecting voltage of the photovoltaic inverter grid-connected module, and the first current sensor is used for collecting current of the photovoltaic inverter grid-connected module.

4. The metrology harvesting circuit of claim 2, wherein, The second collecting unit comprises a second voltage sensor, a second current sensor and a second metering unit, the second metering unit is connected with the second voltage sensor, the second current sensor and the master control module respectively, the second voltage sensor is used for collecting voltage of the generator grid-connected module, and the second current sensor is used for collecting current of the generator grid-connected module.

5. The metrology harvesting circuit of claim 3, wherein, The first metering unit is connected with the master control module in a TTL communication mode.

6. The metrology harvesting circuit of claim 4, wherein, The second metering unit is connected with the master control module in a TTL communication mode.

7. The metrology harvesting circuit of claim 1, wherein, The electric meter is connected with the master control module in an RS485 communication mode.

8. A photovoltaic grid-connected system, characterized by, The photovoltaic grid-connected system comprises a grid-connected bus, a photovoltaic inverter grid-connected module, a generator grid-connected module, a mains grid-connected module and the metering and collecting circuit according to any one of claims 1 to 7, the photovoltaic inverter grid-connected module, the generator grid-connected module and the mains grid-connected module are connected with the grid-connected bus.

9. The photovoltaic grid-tie system of claim 8, wherein, An output line in the mains grid-connected module is sequentially provided with a first circuit breaker and a first relay, and the electric meter is used for collecting voltage and current of a line section between the first circuit breaker and the first relay.

10. The photovoltaic grid-tie system of claim 8, wherein, An output line in the generator grid-connected module is sequentially provided with a second circuit breaker and a second relay, and the collecting module is used for collecting voltage and current of a line section between the second circuit breaker and the second relay.

11. The photovoltaic grid-tie system of claim 8, wherein, An output line in the photovoltaic inverter grid-connected module is sequentially provided with a third circuit breaker and a third relay, and the collecting module is used for collecting voltage and current of a line section after the third relay.

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