CN205160469U - A monitor cell for photovoltaic power generation system monitoring devices - Google Patents

Abstract

The utility model provides a monitor cell for photovoltaic power generation system monitoring devices, it includes: monitoring processor, interchange sensor, the first signal modulate circuit and high accuracy measurement chip, it connects photovoltaic power generation system interchange electrical signal output terminal to exchange the sensor signal input, it takes care of the signal input circuit end to exchange sensor signal output connection the first signal, the first signal takes care of electric circuit signal output end and connects high accuracy measurement chip signal input part, high accuracy measurement chip signal interaction terminal connects monitoring processor signal interaction terminal, monitoring processor shows that connected signal display device shows the signal end. Master power generation system's current operation conditions, in time discover unusually and take measures.

Description

Monitoring unit for photovoltaic power generation system monitoring device

technical field

The utility model relates to the field of photovoltaic power generation monitoring, in particular to a monitoring unit for a photovoltaic power generation system monitoring device.

Background technique

With the development of the power system, the proportion of photovoltaic power generation in the system is increasing. Photovoltaic power generation is greatly affected by environmental factors such as sunlight intensity, temperature, and wind speed. Its power generation characteristics are random and intermittent, and grid-connected operation has a serious impact on grid peak regulation, system safe operation, and power quality. Therefore, it is necessary to monitor the operating status of the entire photovoltaic power generation system and the parameters of the grid-connected point. Through the collection, analysis, processing, and query of monitoring data, the current operating status of the power generation system can be grasped, and abnormal situations can be detected in time and measures taken. However, the corresponding technical problems cannot be well solved in the prior art.

Utility model content

The utility model aims at at least solving the technical problems existing in the prior art, and particularly innovatively proposes a monitoring unit for a monitoring device of a photovoltaic power generation system.

In order to achieve the above purpose of the utility model, the utility model provides a monitoring unit for a photovoltaic power generation system monitoring device, which includes: a monitoring processor, an AC sensor, a first signal conditioning circuit and a high-precision metering chip;

The AC sensor signal input terminal is connected to the photovoltaic power generation system AC signal output terminal, the AC sensor signal output terminal is connected to the first signal conditioning circuit signal input terminal, and the first signal conditioning circuit signal output terminal is connected to the high-precision metering chip signal input terminal The signal interaction terminal of the high-precision metering chip is connected to the signal interaction terminal of the monitoring processor, and the display signal terminal of the monitoring processor is connected to the display signal terminal of the display device.

The monitoring unit for the photovoltaic power generation system monitoring device preferably further includes: a DC sensor, a second signal conditioning circuit, and an AD sampler;

The DC sensor signal input terminal is connected to the DC signal output terminal of the photovoltaic power generation system, the DC sensor signal output terminal is connected to the second signal conditioning circuit signal input terminal, and the second signal conditioning circuit signal output terminal is connected to the AD sampler signal input terminal, so The AD sampling signal interaction terminal is connected to the signal interaction terminal of the monitoring processor, and the display signal terminal of the monitoring processor is connected to the display device display signal terminal.

The beneficial effect of the above technical solution is that it can monitor power quality parameters such as harmonics, power factor, and harmonic distortion rate of the photovoltaic power generation system, grasp the current operating status of the power generation system, find abnormalities in time, and take measures.

In the monitoring unit used in the photovoltaic power generation system monitoring device, preferably, the first signal conditioning circuit includes: a voltage channel circuit and a current channel circuit;

The voltage channel circuit includes: the voltage input end is connected to one end of the first inductor, the other end of the first inductor is connected to one end of the first resistor, and the other end of the first resistor is respectively connected to one end of the second resistor and one end of the first capacitor. The other end of the second resistor is connected to the other end of the first capacitor and then grounded, and one end of the first capacitor is also connected to the signal input end of the high-precision metering chip and the negative electrode of the overvoltage protection diode;

The current channel circuit includes: the current input end is respectively connected to one end of the fourth resistor and one end of the third inductor, the other end of the fourth resistor is connected to one end of the second inductor, and the other end of the third inductor is connected to the positive input end of the AD converter, The other end of the second inductor is connected to the negative input end of the AD converter, and the output end of the AD converter is connected to the signal input end of the high-precision metering chip.

The beneficial effects of the above technical solution are: the regulation function is realized through the voltage channel circuit and the current channel circuit, the circuit design is reasonable, and the operation is stable.

As for the monitoring unit used in the photovoltaic power generation system monitoring device, preferably, the monitoring processor is LPC2368.

As for the monitoring unit used in the photovoltaic power generation system monitoring device, preferably, the high-precision metering chip is ADE7880.

In the monitoring unit used in the monitoring device of the photovoltaic power generation system, preferably, the display device is a liquid crystal touch screen.

In the monitoring unit used in the photovoltaic power generation system monitoring device, preferably, the overvoltage protection diode is a TVS diode.

In the monitoring unit used in the monitoring device of the photovoltaic power generation system, preferably, the fourth resistor is a manganese-copper sampling resistor.

In summary, due to the adoption of the above technical solution, the beneficial effects of the utility model are:

A utility model of photovoltaic power generation system monitoring system combined with LPC2368, ADE7880, DC sampling, and environmental parameter collection box. The device uses LPC2368 controller to control the collection of AC and DC data of photovoltaic system on-site power generation system, and can monitor the monitoring data by communicating with the monitoring host Collection, analysis, processing, query. Through the field operation test, the device can not only collect conventional data such as voltage, current, power, power generation efficiency, and environmental parameters of the photovoltaic power generation system, but also monitor power quality parameters such as harmonics, power factor, and harmonic distortion rate of the photovoltaic power generation system , grasp the current operating status of the power generation system, detect abnormalities in time and take measures. The device can not only be used for the monitoring of the photovoltaic power generation system, but also can be used for other monitoring fields of power quality.

Additional aspects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Description of drawings

The above and/or additional aspects and advantages of the present utility model will become apparent and easy to understand from the description of the embodiments in conjunction with the following drawings, wherein:

Fig. 1 is the overall schematic diagram of the utility model;

Fig. 2 is a schematic diagram of the utility model monitoring unit;

Fig. 3 is a schematic diagram of the voltage channel of the utility model;

Fig. 4 is a schematic diagram of the current channel of the utility model;

Fig. 5 is the utility model LPC2368 and ADE7880 interface schematic diagram;

Fig. 6 is a structural diagram of the environmental parameter collection box of the utility model.

detailed description

Embodiments of the present invention are described in detail below, examples of which are shown in the drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present utility model, but should not be construed as limiting the present utility model.

In describing the present invention, it should be understood that the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical" , "horizontal", "top", "bottom", "inner", "outer" and other indicated orientations or positional relationships are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the utility model and simplifying the description. It does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be construed as limiting the present invention.

In the description of the present utility model, unless otherwise stipulated and limited, it should be noted that the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a mechanical connection or an electrical connection, or it can be The internal communication between two elements may be direct connection or indirect connection through an intermediary. Those of ordinary skill in the art can understand the specific meanings of the above terms according to specific situations.

As shown in Figure 1, the monitoring device of the present invention includes: a monitoring host, a monitoring unit, and an environmental parameter collection box;

The monitoring data interaction end of the monitoring unit is connected to the monitoring data interaction end of the monitoring host, and the environmental data interaction end of the environmental parameter collection box is connected to the environmental data interaction end of the monitoring host. The monitoring unit and the environmental parameter collection box communicate with the monitoring host through the RS485 bus Data interaction.

The beneficial effects of the above technical solution are: real-time monitoring and data collection of the photovoltaic power generation system through the environmental parameter collection box and the monitoring unit, ensuring accurate data monitoring, grasping the current operating status of the power generation system, and timely finding abnormalities and taking measures.

As shown in Figure 2, the monitoring unit includes: a monitoring processor, an AC sensor, a first signal conditioning circuit and a high-precision metering chip;

The AC sensor signal input terminal is connected to the photovoltaic power generation system AC signal output terminal, the AC sensor signal output terminal is connected to the first signal conditioning circuit signal input terminal, and the first signal conditioning circuit signal output terminal is connected to the high-precision metering chip signal input terminal The signal interaction terminal of the high-precision metering chip is connected to the signal interaction terminal of the monitoring processor, and the display signal terminal of the monitoring processor is connected to the display signal terminal of the display device.

The monitoring unit also includes: a DC sensor, a second signal conditioning circuit, and an AD sampler;

The DC sensor signal input terminal is connected to the DC signal output terminal of the photovoltaic power generation system, the DC sensor signal output terminal is connected to the second signal conditioning circuit signal input terminal, and the second signal conditioning circuit signal output terminal is connected to the AD sampler signal input terminal, so The AD sampling signal interaction terminal is connected to the signal interaction terminal of the monitoring processor, and the display signal terminal of the monitoring processor is connected to the display device display signal terminal.

The beneficial effect of the above technical solution is that it can monitor power quality parameters such as harmonics, power factor, and harmonic distortion rate of the photovoltaic power generation system, grasp the current operating status of the power generation system, find abnormalities in time, and take measures.

Preferably, the monitoring processor is LPC2368.

Preferably, the high-precision metering chip is ADE7880.

Preferably, the display device is a liquid crystal touch screen.

As shown in FIG. 3, preferably, the first signal conditioning circuit includes: a voltage channel circuit and a current channel circuit;

The voltage channel circuit includes: the voltage input end is connected to one end of the first inductor, the other end of the first inductor is connected to one end of the first resistor, and the other end of the first resistor is respectively connected to one end of the second resistor and one end of the first capacitor. The other end of the second resistor is connected to the other end of the first capacitor and then grounded, and one end of the first capacitor is also connected to the signal input end of the high-precision metering chip and the negative electrode of the overvoltage protection diode;

As shown in FIG. 4, the current channel circuit includes: the current input terminal is respectively connected to one end of the fourth resistor and one end of the third inductor, the other end of the fourth resistor is connected to one end of the second inductor, and the other end of the third inductor is connected to AD The positive input terminal of the converter, the other end of the second inductor is connected to the negative input terminal of the AD converter, and the output terminal of the AD converter is connected to the signal input terminal of the high-precision metering chip.

The second signal conditioning circuit is the same as above.

The beneficial effects of the above technical solution are: the regulation function is realized through the voltage channel circuit and the current channel circuit, the circuit design is reasonable, and the operation is stable.

Preferably, the monitoring processor is LPC2368.

Preferably, the high-precision metering chip is ADE7880.

As shown in Figure 6, the environmental parameter acquisition box of the utility model includes: a temperature sensor, an irradiance sensor and a wind speed sensor;

The temperature sensor signal interaction end is connected to the temperature signal interaction end of the environmental parameter acquisition processor, the irradiance sensor signal interaction end is connected to the irradiance signal interaction end of the environmental parameter acquisition processor, and the wind speed sensor signal interaction end is connected to The wind speed signal interaction terminal of the environmental parameter collection processor, the temperature sensor, the irradiance sensor and the wind speed sensor are used to collect the environmental parameters of the photovoltaic power generation system.

The beneficial effect of the above technical solution is: the temperature, irradiance and wind speed of the photovoltaic power generation system are collected in real time through the temperature sensor, the irradiance sensor and the wind speed sensor, so as to ensure the accuracy of information collection and monitor its operating status in real time.

The environmental parameter acquisition processor is an MSP430 processor.

The temperature sensor includes: a photovoltaic power generation system monitoring device temperature sensor and an ambient temperature sensor;

The temperature sensor signal interaction terminal of the photovoltaic power generation system monitoring device is connected to the temperature signal interaction terminal of the environmental parameter collection processor, and the environmental temperature sensor signal interaction terminal is also connected to the environmental parameter collection processor signal interaction terminal.

Preferably, the wind speed sensor is DP-FS485.

Preferably, the irradiance sensor is FY-ZF.

Preferably, the temperature sensor is PT100.

The ADE7880 has multiple second-order analog-to-digital converters (ADCs), digital integrators, reference voltage source circuits, and all necessary signal processing circuits to realize high-precision sampling of current and voltage waveforms, total (fundamental and harmonic) active/ Apparent power measurement and RMS calculation, and fundamental active/reactive power measurement. In addition, the ADE7880 calculates phase and neutral currents and harmonic rms, active/reactive/apparent power on phase and phase voltages, and power factor and harmonic distortion on each harmonic for all phases. Total Harmonic Distortion (THD) is also calculated for all currents and voltages. At the same time of high-precision measurement, it also has the function of phase separation system calibration, including RMS offset offset.

The monitoring unit used for the monitoring device of the photovoltaic power generation system is composed of three parts: the monitoring host, the monitoring unit, and the environmental parameter collection box, as shown in Figure 1. The monitoring host implements multi-level security control of the operating system, database system, and application system. Realize monitoring data recording, display, data analysis, data query, system management and other functions. The monitoring unit realizes the collection and measurement of the AC and DC parameters of the photovoltaic power generation system. The environmental parameter acquisition box realizes the acquisition and upload of temperature, solar irradiance and wind speed. The monitoring unit and the environmental parameter collection box communicate with the monitoring host using the RS485 bus.

The monitoring unit is mainly composed of LPC2368ARM processor, AC sensor and signal conditioning circuit, ADE7880 high-precision metering chip, DC sensor and signal conditioning circuit, AD sampler, and LCD touch screen, as shown in Figure 2.

As the control core of the utility model, the LPC2368 microcontroller is used to realize the control of the LCD touch screen, the initialization of the ADE7880 and the acquisition and storage of related measurement data, and the communication with the monitoring host, and the ADE7880 three-phase high-precision multifunctional metering chip, Realize the collection and measurement of AC parameters of the photovoltaic power generation system, the AD sampler realizes the collection of DC parameters, and the LCD touch screen realizes the local display of the operating parameters of the photovoltaic power generation system.

The main function of the signal conditioning circuit is to adjust the analog signal to the range required by the ADE7880 input through filtering, amplification, and other links. The biggest influence on the measurement results is the sampling accuracy. The ADE7880 chip ensures the sampling accuracy of the signal on the internal hardware, and the addition of the digital filter further improves the measurement accuracy of the chip. In order to eliminate the impact of external sensor nonlinearity and precision on the measurement results, the utility model uses a resistor divider network to realize the sampling of the voltage signal, and the sampling resistor adopts a precision resistor with high stability and small temperature drift, and a utility model RC anti-aliasing filter The signal is filtered, and the voltage signal channel is shown in Figure 3.

The amplitude of the output voltage signal in the figure is:

$\mathrm{<span\; class="notranslate">\; V</span>}<span\; class="notranslate">\; =</span>\sqrt{\mathrm{<span\; class="notranslate">\; 3</span>}}\frac{{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; =</span>\sqrt{\mathrm{<span\; class="notranslate">\; 3</span>}}\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1000</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0.381</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; V</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

0.5V less than the maximum input signal amplitude of the ADE7880. The anti-aliasing low-pass filter is set to 8kHz according to the value of the corner frequency, and the resistance value of the low-pass filter R=1kΩ, C=22nF is selected according to formula (2).

${\mathrm{<span\; class="notranslate">\; f</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}\mathrm{<span\; class="notranslate">\; R</span>}\mathrm{<span\; class="notranslate">\; C</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 8000</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$

TVS is overvoltage protection to prevent the instantaneous high voltage of the power grid from causing damage to the circuit, and the magnetic beads are used to absorb high-frequency interference from the power grid.

The current channel uses a manganin sheet to sample the current signal, and the current signal is sampled by the manganin as a voltage signal, which is amplified and then input to the ADE7880, as shown in Figure 3.

In the utility model, the manganese-copper sampling resistor adopts 1 milliohm. After the precision amplifier circuit amplifies the signal by 6 times, the current input to the ADE7880 is passed through the subsequent anti-aliasing filter processing, and the magnetic beads are used to absorb the high frequency from the power grid. interference.

The ADE7880 has three serial port interfaces: a full-throttle I2C interface, a serial peripheral interface (SPI), and a high speed data capture port (HSDC). The ADE7880 has four operating modes (normal power mode, power reduction mode, low power mode, and sleep mode), and the specific mode is determined by the state of the PM0 and PM1 pins. Since the microcontroller can only work in the slave mode when using the HSDC interface, in order to improve the flexibility of data acquisition on the basis of satisfying the data acquisition speed, the utility model adopts the SPI interface of LPC2368 to realize the communication with the SPI interface of ADE7880, The SPI of LPC2368 works in master mode. The wiring diagram of LPC2368 and ADE7880 is shown in Figure 4. In Fig. 5, P1.19 and P1.20 of LPC2368 are respectively connected with PM0 and PM1 of ADE7880 to control the working mode of ADE7880.

Environmental parameter acquisition box hardware

The environmental parameter acquisition box is composed of MSP430 processor, temperature sensor, irradiance sensor, wind speed sensor, etc., as shown in Figure 6.

As the control core of the acquisition box, the MSP430 processor is used to realize the initialization, control, measurement and communication with the monitoring host of the sensor. The irradiance sensor, temperature sensor and wind speed sensor realize the solar irradiance, component temperature, ambient temperature and Acquisition of environmental parameters such as wind speed.

A utility model of photovoltaic power generation system monitoring system combined with LPC2368, ADE7880, DC sampling, and environmental parameter collection box. The device uses LPC2368 controller to control the collection of AC and DC data of photovoltaic system on-site power generation system, and can monitor the monitoring data by communicating with the monitoring host Collection, analysis, processing, query. Through the field operation test, the device can not only collect conventional data such as voltage, current, power, power generation efficiency, and environmental parameters of the photovoltaic power generation system, but also monitor power quality parameters such as harmonics, power factor, and harmonic distortion rate of the photovoltaic power generation system , grasp the current operating status of the power generation system, detect abnormalities in time and take measures. The device can not only be used for the monitoring of the photovoltaic power generation system, but also can be used for other monitoring fields of power quality.

The software program part of the utility model is well known to those skilled in the art.

In the description of this specification, descriptions referring to the terms "one embodiment", "some embodiments", "example", "specific examples", or "some examples" mean that specific features described in connection with the embodiment or example , structures, materials or features are included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although the embodiments of the present invention have been shown and described, those skilled in the art can understand that various changes, modifications, substitutions and modifications, the scope of the present invention is defined by the claims and their equivalents.

Claims (8)

1. for a monitoring means for photovoltaic generating system monitoring device, it is characterized in that, comprising: monitoring processor, ac sensor, the first signal conditioning circuit and computation chip;

Ac sensor signal input part connects photovoltaic generating system ac signal output, described ac sensor signal output part connects the first signal conditioning circuit signal input part, described first signal conditioning circuit signal output part connects computation chip signal input part, described computation chip signal interaction end connects monitoring processor signal interaction end, and described monitoring processor display end connects display unit display end.

2. the monitoring means for photovoltaic generating system monitoring device according to claim 1, is characterized in that, also comprise: direct current transducer, secondary signal modulate circuit, AD sampler;

Direct current transducer signal input part connects photovoltaic generating system DC signal output, described direct current transducer signal output part connects secondary signal modulate circuit signal input part, described secondary signal modulate circuit signal output part connects AD sampler signal input part, described AD sampled signal interaction end connects monitoring processor signal interaction end, and described monitoring processor display end connects display unit display end.

3. the monitoring means for photovoltaic generating system monitoring device according to claim 1, is characterized in that, described first signal conditioning circuit comprises: voltage channel circuit and current channel circuit;

Described voltage channel circuit comprises: voltage input end connects first inductance one end, the described first inductance other end connects first resistance one end, the described first resistance other end connects second resistance one end and first electric capacity one end respectively, ground connection after the described second resistance other end is connected with the first electric capacity other end, described first electric capacity one end also connects computation chip signal input part and overvoltage protection diode negative pole respectively;

Described current channel circuit comprises: current input terminal connects the 4th resistance one end and the 3rd inductance one end respectively, the described 4th resistance other end connects second inductance one end, the described 3rd inductance other end connects AD converter electrode input end, the described second inductance other end connects AD converter negative input, and described AD converter output connects computation chip signal input part.

4. the monitoring means for photovoltaic generating system monitoring device according to claim 1 and 2, is characterized in that, described monitoring processor is LPC2368.

5. the monitoring means for photovoltaic generating system monitoring device according to claim 1, is characterized in that, described computation chip is ADE7880.

6. the monitoring means for photovoltaic generating system monitoring device according to claim 1 and 2, is characterized in that, described display unit is liquid crystal touch display screen.

7. the monitoring means for photovoltaic generating system monitoring device according to claim 3, is characterized in that, described overvoltage protection diode is TVS diode.

8. the monitoring means for photovoltaic generating system monitoring device according to claim 3, is characterized in that, described 4th resistance is copper-manganese sampling resistor.