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CN112039424A - A control system and control method for preventing snow on photovoltaic roofs - Google Patents

️Fri Dec 04 2020

一种预防光伏屋顶积雪的控制系统及其控制方法A control system and control method for preventing snow on photovoltaic roofs

技术领域technical field

本发明涉及光伏技术领域，具体涉及一种预防光伏屋顶积雪的控制系统及其控制方法。The invention relates to the field of photovoltaic technology, in particular to a control system and a control method for preventing snow accumulation on photovoltaic roofs.

背景技术Background technique

中国华东、中南等地区人口集中、工商业发达，屋顶光伏系统消纳比列大，投资回报率高；但是光伏车棚、光伏屋顶、特别是安装在彩钢瓦厂房屋顶的大面积光伏电站，虽然每年下雪次数不多，但仍然可能出现大规模降雪天气，这样就可能出现屋顶因积雪承重过大的安全性问题。In East China, Central and South China and other regions with concentrated population and developed industry and commerce, rooftop photovoltaic systems have a large consumption ratio and a high return on investment; however, photovoltaic carports, photovoltaic roofs, especially large-area photovoltaic power stations installed on the roof of color steel tile workshops, although every year It doesn't snow much, but there is still the potential for massive snowfall, which can lead to safety issues with roofs bearing too much snow.

现有技术中对光伏屋顶的除雪除冰主要依赖人工，但降雪天气具有随机性，降雪持续时间不可确定，且屋顶作业具有危险性；此外，为及时除雪也需提前组织大量人力等待，劳务支出过大。In the prior art, the snow and ice removal of photovoltaic roofs mainly relies on manual work, but the snowfall weather is random, the duration of snowfall is uncertain, and the roof operation is dangerous; in addition, in order to remove snow in time, a large amount of manpower needs to be organized in advance to wait, labor costs is too big.

发明内容SUMMARY OF THE INVENTION

为解决上述技术问题，本发明提供一种预防光伏屋顶积雪的控制系统及其控制方法。In order to solve the above technical problems, the present invention provides a control system and a control method for preventing snow accumulation on photovoltaic roofs.

为解决上述技术问题，本发明采用如下技术方案：In order to solve the above-mentioned technical problems, the present invention adopts the following technical solutions:

一种预防光伏屋顶积雪的控制系统，包括：A control system for preventing snow accumulation on photovoltaic roofs, comprising:

光伏组件，其两端反向通电后产生热量；Photovoltaic modules, which generate heat after reverse energization at both ends;

整流电路，其与电网、光伏组件串联，用于将交流电整流为直流电后反向通入光伏组件；A rectifier circuit, which is connected in series with the power grid and the photovoltaic modules, is used to rectify the alternating current into direct current and then reversely feed the photovoltaic modules;

温度传感器，其安装在光伏组件上且用于采集光伏组件的温升；a temperature sensor, which is installed on the photovoltaic module and used to collect the temperature rise of the photovoltaic module;

图像传感器，其安装在光伏组件上且用于检测降雪状态；an image sensor mounted on the photovoltaic module and used to detect snowfall conditions;

控制器，其与整流电路、温度传感器以及图像传感器连接。The controller is connected with the rectifier circuit, the temperature sensor and the image sensor.

进一步地，还包括与控制器连接的无线通信模块。Further, it also includes a wireless communication module connected with the controller.

一种所述预防光伏屋顶积雪的控制系统的控制方法，包括以下步骤：A control method of the control system for preventing snow on photovoltaic roofs, comprising the following steps:

步骤一：通过图像传感器周期性地获取屋顶的状态图像，并通过事先训练好的机器学习模型对状态图像进行分析，获得气象状态；Step 1: Periodically obtain the state image of the roof through the image sensor, and analyze the state image through the pre-trained machine learning model to obtain the meteorological state;

步骤二：如开始降雪，则对光伏组件进行反向通电；通过温度传感器检测光伏组件的温升，并根据温升控制光伏组件的反向通电功率，使温升维持在设定值；Step 2: If snow starts to fall, reversely energize the photovoltaic modules; detect the temperature rise of the photovoltaic modules through the temperature sensor, and control the reverse energization power of the photovoltaic modules according to the temperature rise, so that the temperature rise is maintained at the set value;

步骤三：如停止降雪，则停止对光伏组件进行反向通电。Step 3: If the snowfall stops, stop the reverse energization of the PV modules.

具体地，步骤一中，所述气象状态包括日照条件、降雪状态和降雪等级。Specifically, in step 1, the meteorological state includes sunshine conditions, snowfall status and snowfall level.

具体地，如停止降雪时日照条件能够用于光伏发电，则停止对光伏组件进行反向通电后，使用光伏组件进行发电，并将光伏组件发出的直流电进行逆变处理后送入电网。Specifically, if the sunshine conditions can be used for photovoltaic power generation when the snowfall is stopped, after the reverse power-on of the photovoltaic modules is stopped, the photovoltaic modules are used to generate electricity, and the direct current generated by the photovoltaic modules is inverted and sent to the grid.

具体地，温升的设定值与降雪等级呈正相关的关系。Specifically, the set value of the temperature rise is positively correlated with the snowfall level.

具体地，光伏组件的温升是指光伏组件高出环境的温度，步骤二中根据温升控制光伏组件的反向通电功率时，如温升小于设定值，则提高光伏组件的反向通电功率；如温升大于设定值，则降低光伏组件的反向通电功率或者暂时停止反向通电。Specifically, the temperature rise of the photovoltaic module refers to the temperature of the photovoltaic module higher than that of the environment. In step 2, when the reverse power of the photovoltaic module is controlled according to the temperature rise, if the temperature rise is less than the set value, the reverse power of the photovoltaic module is increased. Electric power; if the temperature rise is greater than the set value, reduce the reverse energization power of the PV module or temporarily stop the reverse energization.

具体地，步骤三中，停止降雪并停止对光伏组件进行反向通电后，所述控制系统进入警戒状态，并在警戒状态维持设定时间，如在上述设定时间内无降雪，控制系统根据气象预报信息退出至低功耗的待机状态。Specifically, in step 3, after the snowfall is stopped and the reverse power-on of the photovoltaic modules is stopped, the control system enters an alert state, and maintains the alert state for a set time. If there is no snowfall within the above-mentioned set time, the control system will The weather forecast information exits to a low-power standby state.

具体地，根据气象预报信息，如不再下雪但在未来的设定时间内仍有降雪，则控制系统维持在警戒状态；如不再下雪但在未来的设定时间内不再降雪，则控制系统进入待机状态；所述控制系统进入警戒状态时，通过图像传感器周期性地获取屋顶的状态图像，并通过事先训练好的机器学习模型对状态图像进行分析，获得当前的气象状态，根据气象状态判断是否进入工作状态，即开始对光伏组件进行反向通电；所述控制系统进入待机状态时，所述图像传感器不再工作，但控制系统能够通过手动指令进入警戒状态。Specifically, according to the weather forecast information, if it no longer snows but it still falls within the set time in the future, the control system will maintain the alert state; Then the control system enters the standby state; when the control system enters the alert state, the state image of the roof is periodically obtained through the image sensor, and the state image is analyzed through the pre-trained machine learning model to obtain the current weather state. The meteorological state determines whether to enter the working state, that is, reverse power-on of the photovoltaic modules is started; when the control system enters the standby state, the image sensor no longer works, but the control system can enter the alert state through manual commands.

与现有技术相比，本发明的有益技术效果是：Compared with the prior art, the beneficial technical effects of the present invention are:

通过图像识别对降雪状态以及降雪等级进行检测，并通过检测温升和光伏组件的反向通电功率形成闭环控制，使得化雪流程自动化、安全可控；消除了工人在屋顶作业的安全风险，确保光伏屋顶不积雪，且能实现光伏屋顶的快速除雪。The snowfall status and snowfall level are detected through image recognition, and closed-loop control is formed by detecting temperature rise and reverse energization power of photovoltaic modules, making the snow melting process automatic, safe and controllable; eliminating the safety risk of workers working on the roof, ensuring The photovoltaic roof does not accumulate snow, and can achieve rapid snow removal from the photovoltaic roof.

附图说明Description of drawings

图1为本发明的工作原理示意图；Fig. 1 is the working principle schematic diagram of the present invention;

图2为本发明整流电路的结构示意图；2 is a schematic structural diagram of a rectifier circuit of the present invention;

图3为本发明控制系统整体的结构示意图。FIG. 3 is a schematic structural diagram of the overall control system of the present invention.

具体实施方式Detailed ways

下面结合附图对本发明的一种优选实施方式作详细的说明。A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

中高纬度地区的光伏屋顶、光伏车棚、安装在彩钢瓦厂房屋顶的大面积光伏电站，在大规模降雪天气下，容易出现屋顶积雪承重过大的安全性问题。In the middle and high latitudes, photovoltaic roofs, photovoltaic carports, and large-area photovoltaic power plants installed on the roof of color steel tile workshops are prone to safety problems such as excessive snow load on the roof in large-scale snowfall weather.

如图1和3所示，本发明提供了一种预防光伏屋顶积雪的控制系统，包括：As shown in Figures 1 and 3, the present invention provides a control system for preventing snow accumulation on photovoltaic roofs, including:

光伏组件，其两端反向通电后产生热量；Photovoltaic modules, which generate heat after reverse energization at both ends;

图像传感器2，其安装在光伏组件上且用于检测降雪状态；an image sensor 2, which is installed on the photovoltaic module and used to detect snowfall conditions;

控制器，其与整流电路、温度传感器以及图像传感器连接。The controller is connected with the rectifier circuit, the temperature sensor and the image sensor.

本发明通过结合多种传感器信号以及机器学习技术，实现降雪预警及降雪状态和等级的检测，并通过检测温升和光伏组件的反向通电功率形成闭环控制，可以有效解决降雪天气下光伏屋顶带来的承重隐患，防止光伏板表面积雪；此外，该系统也能完成光伏板表面的快速除雪，节约人力成本，应用范围包括光伏屋顶、光伏车棚、光伏电站等。By combining various sensor signals and machine learning technology, the invention realizes snowfall warning and detection of snowfall status and grade, and forms closed-loop control by detecting temperature rise and reverse energization power of photovoltaic modules, which can effectively solve the problem of photovoltaic roof belts in snowy weather. In addition, the system can also complete the rapid snow removal on the surface of photovoltaic panels, saving labor costs, and the application scope includes photovoltaic roofs, photovoltaic carports, photovoltaic power plants, etc.

若干个光伏组件串联后，形成能够输出直流电的电路单元集合，被称为光伏组串；其中光伏组件即我们通常所说的光伏板。After several photovoltaic modules are connected in series, a set of circuit units capable of outputting direct current is formed, which is called a photovoltaic string; the photovoltaic module is what we usually call a photovoltaic panel.

图1中的PV代表光伏组件。PV in Figure 1 stands for Photovoltaic Module.

把光伏组件作为一个负载，在光伏组件两极施加反向电压，当电流通过时会在光伏组件内部PN结区域产热，从而使光伏组件表面温度均匀升高，起到融雪的作用。The photovoltaic module is used as a load, and a reverse voltage is applied to the two poles of the photovoltaic module. When the current passes through, heat will be generated in the PN junction area inside the photovoltaic module, so that the surface temperature of the photovoltaic module will increase evenly, which plays the role of snow melting.

如图2所示，所述整流电路完成市电到直流电的转换，并通过PWM的方法实现对反向通电功率的控制；本发明采用的整流电路以桥式整流电路为基础，现有的商用整流电路多为在该整流电路的原理上发展而来，其主要通过整流二极管、电容滤波器、电感滤波器将交流电输出为平滑的直流电，并为光伏组件进行反向通电。As shown in FIG. 2 , the rectifier circuit completes the conversion from commercial power to direct current, and realizes the control of reverse energization power by means of PWM; the rectifier circuit adopted in the present invention is based on a bridge rectifier circuit, and the existing commercial The rectifier circuit is mostly developed on the principle of the rectifier circuit. It mainly outputs the alternating current into a smooth direct current through a rectifier diode, a capacitor filter and an inductance filter, and reversely energizes the photovoltaic modules.

所述控制器包括布置在近端的微控制器3以及布置在远端的服务器。The controller includes a microcontroller 3 arranged at the near end and a server arranged at the far end.

所述微控制器连接整流电路、图像传感器、温度传感器，其可以通过继电器6的通断实现各光伏组串的通断；在设计上为满足功率匹配，将一路光伏组串分为多组光伏组件；当市电通过整流电路后转化为稳定的直流电，通过升压处理和电路转换处理后，反向通入到一个光伏组串的两端，对光伏板进行均匀加热，使降落在光伏板表面的雪及时融化；例如分为M组，第一组加热X时间之后，第二组加热X时间，之后第三组加热X时间，按上述方式依次进行对剩余组进行加热，直至第M组加热X时间，并再次轮换到第一组加热X时间，如此循环加热，加热时间可根据需要进行设置；上述分组的目的在于：如果继电器的功率无法支持所有光伏组件同时进行加热，但又需要对所有光伏组件的表面进行除雪，进行分组加热既能够满足功率匹配，又能够对光伏板的表面进行均匀加热除雪。The microcontroller is connected to a rectifier circuit, an image sensor, and a temperature sensor, which can realize the on-off of each photovoltaic string through the on-off of the relay 6; in order to meet the power matching, one photovoltaic string is divided into multiple groups of photovoltaic strings. Module; when the commercial power is converted into a stable DC power through the rectifier circuit, after the boosting process and the circuit conversion process, it is reversely connected to both ends of a photovoltaic string to uniformly heat the photovoltaic panel, so that it falls on the photovoltaic panel. The snow on the surface melts in time; for example, it is divided into M groups. After the first group is heated for X time, the second group is heated for X time, and then the third group is heated for X time, and the remaining groups are heated in sequence in the above manner until the Mth group is heated. Heating for X time, and then rotate to the first group of heating X time again, so that the heating cycle can be set as needed; the purpose of the above grouping is: if the power of the relay cannot support all photovoltaic modules to heat at the same time, but it is necessary to Snow removal is performed on the surface of all photovoltaic modules, and group heating can not only satisfy power matching, but also uniformly heat and remove snow on the surface of photovoltaic panels.

所述温度传感器负责监控每一组光伏组件的温度变化；进行融雪时，由于“边界递减效应”，温升与融雪速度并非一直成正比，在温升较高时，融雪速度的增长率变小，在未通电的时间内，光伏组件可以利用余温融化积雪，通过控制通电周期，或者根据温度传感器的参数，使光伏组件的温升与融雪速度保持在正比例区间内，能够提高能量的利用效率。The temperature sensor is responsible for monitoring the temperature change of each group of photovoltaic modules; during snow melting, due to the "boundary decreasing effect", the temperature rise and the snow melting speed are not always proportional, and when the temperature rise is high, the growth rate of the snow melting speed becomes smaller. , During the time when no power is applied, the photovoltaic modules can use the residual temperature to melt the snow. By controlling the power-on cycle or according to the parameters of the temperature sensor, the temperature rise of the photovoltaic modules and the snow melting speed are kept in a proportional range, which can improve the utilization of energy. efficiency.

一种预防光伏屋顶积雪的控制系统的控制方法，包括以下步骤：A control method for a control system for preventing snow on a photovoltaic roof, comprising the following steps:

步骤一：通过图像传感器周期性地获取屋顶的状态图像，并通过事先训练好的机器学习模型对状态图像进行分析，获得气象状态。Step 1: Periodically obtain the state image of the roof through the image sensor, and analyze the state image through the pre-trained machine learning model to obtain the meteorological state.

所述图像传感器设立在光伏组件附近，采集光伏屋顶以及周围的状态图像，通过机器学习的方法判断当前是否处于降雪状态、日照强度是否足够光伏板发电、判断降雪等级；对当前状态完成判断后，将气象状态回传给微控制器，微控制器通过控制继电器、反向通电功率等策略进行控制。The image sensor is set up near the photovoltaic modules, collects the state images of the photovoltaic roof and the surroundings, and judges whether the current state of snowfall is in a state of snowfall, whether the sunshine intensity is sufficient for photovoltaic panels to generate electricity, and judges the snowfall level through the method of machine learning; after the judgment of the current state is completed, The weather state is sent back to the microcontroller, and the microcontroller controls it through strategies such as controlling relays and reverse energization power.

利用机器学习方法对图片进行分析，得到分类结果，是较为成熟的技术，本发明利用事先训练好的机器学习模型对状态图像进行分析，得到气象状态的分类结果；其中对上传的图像进行识别与分类的程序运行在远端的服务器上。It is a relatively mature technology to use the machine learning method to analyze the picture and obtain the classification result. The present invention uses the machine learning model trained in advance to analyze the state image to obtain the classification result of the meteorological state; wherein the uploaded image is identified and analyzed. Classified programs run on remote servers.

步骤二：如开始降雪，则对光伏组件进行反向通电；通过温度传感器检测光伏组件的温升，并根据温升控制光伏组件的反向通电功率，使温升维持在设定值。Step 2: If the snow starts to fall, reversely energize the photovoltaic modules; detect the temperature rise of the photovoltaic modules through the temperature sensor, and control the reverse energization power of the photovoltaic modules according to the temperature rise, so that the temperature rise is maintained at the set value.

微控制器可周期性的改变继电器的通断，从而实现同一路组串内的多组光伏组件进行轮换加热，进入除雪状态的初期时功率较大，光伏板表面快速升温，温升达到设定值附近时，逐渐降低反向通电功率，维持温升不下降，通过微控制器对反向通电功率进行动态调控；本实施例中，温升控制在10℃，能够实现除雪且功耗较低；具体应用中温升的设定值以当地气候环境为准。The microcontroller can periodically change the on-off of the relay, so that multiple groups of photovoltaic modules in the same string can be heated alternately. In the initial stage of snow removal, the power is large, the surface of the photovoltaic panel heats up rapidly, and the temperature rise reaches the set value. When the temperature is near the value, the reverse power is gradually reduced to keep the temperature rise from falling, and the reverse power is dynamically regulated by the microcontroller; in this embodiment, the temperature rise is controlled at 10°C, which can achieve snow removal and low power consumption ; The set value of temperature rise in specific applications is subject to the local climate environment.

步骤三：如停止降雪，则停止对光伏组件进行反向通电。Step 3: If the snowfall stops, stop the reverse energization of the PV modules.

如图2所示，每一路光伏组串与一个逆变器连接，光伏组串发出的直流电通过逆变器后生成交流电，并入电网。As shown in Figure 2, each PV string is connected to an inverter, and the DC power generated by the PV string passes through the inverter to generate AC power, which is merged into the grid.

具体地，温升的设定值与降雪等级呈正相关关系；如大雪时，可以使光伏组件具有较高的温升，避免雪量过大导致的化雪能力不足。Specifically, the set value of temperature rise is positively correlated with the level of snowfall; for example, when there is heavy snow, the photovoltaic modules can have a higher temperature rise, so as to avoid insufficient snow melting ability caused by excessive snow volume.

如图3所示，还包括与控制器连接的无线通信模块；所述无线通信模块能够发射5G信号、4G信号或者3G信号，微控制器与无线通信模块连接，微控制器通过无线通信模块完成与服务器的通信。As shown in Figure 3, it also includes a wireless communication module connected to the controller; the wireless communication module can transmit 5G signals, 4G signals or 3G signals, the microcontroller is connected to the wireless communication module, and the microcontroller is completed through the wireless communication module Communication with the server.

手机控制软件7能够实现如下功能：手动设定光伏电站的位置并调用该位置的气象信息，实现降雪预警和降雪等级预测；手动设定融雪等级，不同融雪等级对应不同的除雪速率；全自动模式，由本发明的控制方法自动控制除雪流程。The mobile phone control software 7 can realize the following functions: manually set the position of the photovoltaic power station and call the meteorological information of the position to realize snowfall warning and snowfall grade prediction; manually set the snowmelt grade, and different snowmelt grades correspond to different snow removal rates; automatic mode , the snow removal process is automatically controlled by the control method of the present invention.

手机控制软件还能够实现与控制系统的通信和远程操控，例如回传实时图像，人工判断除雪效果和降雪等级，或者实现打开或者关闭控制系统；当服务器收到图像回传请求时，通过微控制器控制图像传感器完成状态图像的采集和图像上传。The mobile phone control software can also realize communication and remote control with the control system, such as sending back real-time images, manually judging the snow removal effect and snowfall level, or turning on or off the control system; The controller controls the image sensor to complete the acquisition of the status image and the image upload.

本发明的控制系统平时工作在待机状态下，手机控制软件得到将会有降雪的信息后自动将控制系统切换到警戒状态，或者通过手机将降雪预警发送给用户，用户可根据实际情况手动对系统进行设置。The control system of the present invention usually works in a standby state, and the mobile phone control software automatically switches the control system to the alert state after getting the information that there will be snowfall, or sends the snowfall warning to the user through the mobile phone, and the user can manually adjust the system according to the actual situation. Make settings.

本发明适用于不常下雪的中纬度地区，能够实现边下雪边化雪，防止光伏屋顶积雪，避免屋顶超过其承重上限；也适用于雪期较长的高纬度地区，能够完成快速化雪，避免因长时间的积雪降低冬季光伏电站的发电量。The present invention is suitable for mid-latitude areas where it does not often snow, and can realize snow melting while snowing, prevent the photovoltaic roof from accumulating snow, and prevent the roof from exceeding the upper limit of its bearing capacity; Melting snow to avoid reducing the power generation of photovoltaic power plants in winter due to long-term snow accumulation.

对于本领域技术人员而言，显然本发明不限于上述示范性实施例的细节，而且在不背离本发明的精神或基本特征的情况下，能够以其他的具体形式实现本发明。因此无论从哪一点来看，均应将实施例看作是示范性的，而且是非限制性的，本发明的范围由所附权利要求而不是上述说明限定，因此旨在将落在权利要求的等同要件的含义和范围内的所有变化囊括在本发明内，不应将权利要求中的任何附图标记视为限制所涉及的权利要求。It will be apparent to those skilled in the art that the present invention is not limited to the details of the above-described exemplary embodiments, but that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. The embodiments are therefore to be regarded in all respects as illustrative and not restrictive, the scope of the invention being defined by the appended claims rather than the foregoing description, and are therefore intended to fall within the scope of the appended claims. All changes that come within the meaning and range of equivalents are embraced within the invention, and any reference signs in the claims shall not be construed as limiting the scope of the claims involved.

此外，应当理解，虽然本说明书按照实施方式加以描述，但并非每个实施方式仅包含一个独立技术方案，说明书的这种叙述方式仅仅是为了清楚起见，本领域技术人员应当将说明书作为一个整体，各实施例中的技术方案也可以经适当组合，形成本领域技术人员可以理解的其他实施方式。In addition, it should be understood that although this specification is described in terms of embodiments, not every embodiment only includes an independent technical solution, and this description in the specification is only for the sake of clarity, and those skilled in the art should take the specification as a whole, The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.