A ternary integrated PVT heat pump comprehensive energy system and a control method thereof

Abstract

The present application relates to a kind of ternary integrated PVT heat pump comprehensive energy systems and control method, PVT heat pump system includes PVT array, heat pump unit, energy storage water tank;Ternary integrated power system includes PVT and photovoltaic hybrid array, rectifier, inverter, MCU controller, grid-connected inverter and power grid.PVT and photovoltaic hybrid array are connected in series and parallel by several PVT components and photovoltaic components, array output voltage meets the input voltage range of inverter;Rectifier, inverter and MCU controller realize the power regulation between photovoltaic, power grid and load compressor three elements;MCU controller reads real-time hourly weather forecast, and according to weather forecast result, it is selected to determine control method switching.Heat pump unit, PVT array and energy storage water tank are realized cold, hot preparation and storage by four-way reversing valve, and grid-connected inverter realizes photovoltaic power generation grid-connected.The present application controls ternary integrated power system mode switching by hourly weather forecast, improves photovoltaic drive compressor electric energy conversion efficiency and power grid stability.

Description

Technical Field

[0001] This invention relates to the field of solar energy utilization technology, specifically to a PVT heat pump integrated energy system and its control method applied to buildings, which realizes three-dimensional regulation of photovoltaic, power grid and load compressor. Background Technology

[0002] The overexploitation and use of fossil fuels has triggered a series of adverse effects globally, including energy crises and global warming. The building industry accounts for approximately 40% of total energy consumption, making improved building energy efficiency a key means of saving energy and reducing greenhouse gas emissions. The concept of zero-energy buildings has emerged in response to this need. The integration of solar energy technology with buildings provides energy at its source, serving as the core technological support for zero-energy buildings. However, solar energy is intermittent and unpredictable. Existing solutions, such as grid connection regulation, increase the pressure on the power grid, hindering its stable operation. Energy storage devices, such as batteries, are expensive and bulky, all of which pose major obstacles to the widespread adoption of solar energy systems.

[0003] The authorized invention patent with application number ZL201710653981.3 discloses a PVT heat pump system that can achieve day and night time-sharing heat, electricity, and cooling supply using solar radiation and sky cold radiation. Although it can realize combined photovoltaic power generation, heating, and cooling, this invention adopts a power operation mode of directly connecting photovoltaic power generation to the grid and drawing electricity from the grid. With the increasing proportion of solar power generation, the pressure on grid regulation continues to expand, grid safety accidents occur frequently, and the intermittent nature of solar power generation leads to large-scale curtailment of photovoltaic power plants, resulting in a huge waste of photovoltaic power. In addition, the pressure-bearing capacity of the PVT array heat exchange aluminum plate in this invention is limited, and the cooling mode can only operate at night. However, the demand for building cooling is greatest in summer, and time-sharing operation not only increases the capacity of the cold storage box, but also reduces the daily cold storage capacity.

[0004] Therefore, there is an urgent need for a PVT heat pump integrated energy system and control method that can improve power conversion efficiency, alleviate grid pressure, expand cooling operation conditions, and is safe and reliable. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing PVT heat pump integrated energy systems, adapt to practical needs, and provide a three-element integrated PVT heat pump integrated energy system and control method.

[0006] To achieve the objectives of this invention, the technical solution adopted is as follows: A ternary integrated PVT heat pump energy system is disclosed, comprising a PVT heat pump system and a ternary integrated power system. The PVT heat pump system consists of a PVT array, a heat pump unit, and an energy storage tank, which are connected by a four-way reversing valve to form a circulation system that realizes cooling, heating, cold storage, and heat storage functions. The ternary integrated power system includes a PVT and photovoltaic hybrid array, an electromagnetic relay A, a rectifier, an electromagnetic relay B, an inverter, an MCU controller, a grid-connected inverter, and a power grid. The PVT and photovoltaic hybrid array, grid-connected inverter, and power grid are connected in series to enable the PVT and photovoltaic hybrid array to output power to the power grid. The power grid, rectifier, inverter, and heat pump unit are connected in series to enable the operation of the heat pump unit's compressor to be controlled by power supplied from the power grid. Electromagnetic relay A is connected between the output terminal of the PVT and photovoltaic hybrid array and the inverter to enable the PVT and photovoltaic hybrid array to output power to the compressor of the heat pump unit. Electromagnetic relay B is connected between the inverter and the rectifier to enable the power supply between the power grid and the compressor. The MCU controller is connected to electromagnetic relays A and B and controls their on / off states. The MCU controller is also connected to the inverter and collects the real-time power of the inverter. The MCU controller is also connected to the PVT and photovoltaic hybrid array, and the compressor in the heat pump unit and collects the output power of the PVT and photovoltaic hybrid array and the operating power of the compressor in real time.

[0007] The PVT and photovoltaic hybrid array is composed of several hybrid modules connected in parallel; the hybrid module is composed of several PVT components and photovoltaic components connected in series, and the PVT components in the hybrid module are connected in series with each other, with PVT components and photovoltaic components connected in series with each other, and with photovoltaic components connected in series with each other through positive and negative electrodes.

[0008] The rectifier consists of six rectifier diodes arranged in a three-wire configuration, and the inverter is a single-stage inverter based on an IGBT power conversion module, and the inverter contains two capacitors.

[0009] Furthermore, this invention also discloses a control method for a ternary integrated PVT heat pump energy system, using the system described above, comprising: (1) If the PVT heat pump system stops operating, both electromagnetic relay A and electromagnetic relay B will be disconnected, and the PVT and photovoltaic hybrid array will generate electricity through the grid-connected inverter.

[0010] (2) When the PVT heat pump system is running, the MCU controller reads the hourly weather forecast in real time. If it is a sunny day, the electromagnetic relay A switch is closed and the electromagnetic relay B switch is opened; the compressor adaptively matches the maximum power output point of the PVT and photovoltaic hybrid array under varying irradiance conditions. If the output power of the PVT and photovoltaic hybrid array is lower than the rated operating power of the compressor, the photovoltaic DC power output by the PVT and photovoltaic hybrid array directly drives the compressor to operate at a variable frequency. If the output power of the PVT and photovoltaic hybrid array is higher than the rated operating power of the compressor, the compressor maintains its rated power operation, and the photovoltaic DC power of the PVT and photovoltaic hybrid array that exceeds the rated power of the compressor is transmitted to the grid through the grid-connected inverter. If the output power of the PVT and photovoltaic hybrid array is equal to the rated operating power of the compressor, the compressor will maintain its rated power operation. (3) When the PVT heat pump system is running, the MCU controller reads the hourly weather forecast in real time. If it is not a sunny day, the electromagnetic relay A and electromagnetic relay B switches are closed. The grid voltage is rectified into a stable DC power by the rectifier. At the same time, the operating voltage of the PVT and photovoltaic hybrid array is corrected and the constant voltage method is used to keep the PVT and photovoltaic hybrid array at the maximum power point output. If the output power of the PVT and photovoltaic hybrid array is lower than the rated operating power of the compressor, the photovoltaic DC power output by the PVT and photovoltaic hybrid array and the power grid work together to drive the compressor to maintain rated power operation. If the output power of the PVT and photovoltaic hybrid array is higher than the rated operating power, the electromagnetic relay B will be disconnected, the compressor will maintain the rated power operation, and the excess photovoltaic DC power of the PVT and photovoltaic hybrid array that exceeds the rated power of the compressor will be transmitted to the grid through the grid-connected inverter. If the output power of the PVT and photovoltaic hybrid array is equal to the rated operating power of the compressor, the compressor will maintain its rated power operation.

[0011] Furthermore, when the PVT heat pump system is operating in cooling mode, the upper limit of the PVT heat pump system's exhaust pressure is used as a limiting condition for the compressor's operating frequency. When the compressor's exhaust pressure is higher than the pressure that the PVT and photovoltaic hybrid array flow channels can withstand, the compressor's operating frequency is reduced to lower the exhaust pressure. The compressor's operating frequency is adjusted according to changes in irradiance and ambient temperature to ensure that the exhaust pressure is always lower than the upper limit.

[0012] The specific method for the compressor's adaptive frequency conversion to match the maximum power output point is as follows: The MCU controller acquires the photovoltaic power generation of the PVT and photovoltaic hybrid array and the compressor operating frequency twice, before and after the acquisition, and outputs a disturbance control signal to the inverter to cause the compressor frequency to change with a certain step period; the output power of the PVT and photovoltaic hybrid array before and after the disturbance is compared. If the power output of the PVT and photovoltaic hybrid array after the disturbance is greater than that before the disturbance, the direction of the compressor frequency disturbance of the heat pump unit remains unchanged; If the output power of the PVT and photovoltaic hybrid array after the disturbance is less than that before the disturbance, the compressor frequency of the heat pump unit will change in the opposite direction.

[0013] If the output power of the perturbed PVT and the photovoltaic hybrid array is equal, then the output power is continuously measured and compared.

[0014] The beneficial effects of this invention are as follows: 1. This invention features multiple operating strategies: independent photovoltaic (PV) DC power drive for the compressor, combined PV DC power and grid power drive for the compressor, and grid-connected PV DC power, thereby improving the efficiency of photovoltaic power generation, heating and heat storage, and cooling and cold storage. Under sunny conditions, the ternary PVT heat pump integrated energy system preferentially operates in the PV DC power independent compressor drive mode. The PV DC power is directly driven by the compressor after a single-stage inverter, significantly improving the energy conversion efficiency from DC to AC power to drive the compressor. Under cloudy conditions, the ternary PVT heat pump integrated energy system utilizes the high voltage stability of the grid to achieve combined PV DC power and grid power drive for the compressor. Specifically, the PV DC power and grid power complement each other in jointly driving the compressor, significantly improving the energy conversion efficiency from DC to AC power to drive the compressor. Furthermore, when there is no demand for cooling or heating, the compressor stops operating, and grid-connected PV power generation meets the general applicability of grid power generation.

[0015] 2. This invention combines the characteristics of photovoltaic power generation and compressor operation to achieve electrical isolation between the photovoltaic DC power and the power grid during compressor operation, thereby improving the stability of power grid operation and reducing power grid safety faults. The ternary integrated PVT heat pump energy system and control method achieve a balance between power supply and demand among photovoltaic, power grid, and compressor, utilizing their respective power characteristics to promote each other functionally while remaining independent. When energy storage is needed, the photovoltaic DC power flows directly to the compressor, greatly reducing the photovoltaic system's dependence on the power grid and effectively reducing the grid-connected penetration rate of photovoltaic power generation.

[0016] 3. This invention is simple in technology, low in cost, and safe and reliable. It does not increase costs compared to existing PVT heat pump integrated energy systems, while simultaneously satisfying the diverse functions of existing technologies such as photovoltaic grid connection, compressor frequency conversion, and integrated heating and cooling. Furthermore, addressing the safety assurance issue of cooling operation under adverse conditions in PVT heat pump integrated energy systems, it proposes an adaptive adjustment of the compressor exhaust temperature based on the compressor operating frequency to ensure safe operation of the system's cooling mode under adverse conditions, thus expanding the system's operating range for cooling. The ternary integrated PVT heat pump integrated energy system is ready to use immediately, unrestricted, and meets the output capacity for heating and cooling under varying loads.

[0017] 4. This invention employs photovoltaic (PV) direct-drive compressor operation for energy storage, improving the energy conversion efficiency of multi-stage conversion from PV DC to compressor AC. Addressing the intermittent nature of PV power generation and considering applicability to various weather conditions, it utilizes multiple control methods to achieve maximum electrical isolation between PV power generation and the grid, enabling self-consumption and grid connection of surplus power, reducing PV grid-connected electricity and alleviating grid pressure. It also provides a refrigeration operation technology solution based on exhaust pressure control, addressing the pressure limitations of PVT arrays as condensers in heat pump systems, enhancing cold storage capacity, and ensuring a safe and reliable refrigeration process. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a three-element integrated PVT heat pump energy system and its control method.

[0019] Figure 2 This is a schematic diagram of a hybrid array structure of PVT and photovoltaic.

[0020] Figure 3 This is a schematic diagram of the ternary wiring structure of the power grid, PVT and photovoltaic hybrid array, and compressor.

[0021] Figure 4 Flowchart of the control process for a photovoltaic DC-powered independently driven compressor.

[0022] Explanation of reference numerals in the attached diagram: ①PVT array; ②Photovoltaic array; ③Grid-connected inverter; ④Grid; ⑤Electromagnetic relay A; ⑥Rectifier; ⑦Electromagnetic relay B; ⑧Inverter; ⑨MCU controller; ⑩Heat pump unit; ⑪Energy storage tank. Detailed Implementation

[0023] The following is in conjunction with reference to [see also] Figures 1 to 4 The present invention is further illustrated by the embodiments: Example 1: A ternary integrated PVT heat pump energy system. This system comprises two parts: a PVT heat pump system and a ternary integrated power system. For example... Figure 1 As shown, the PVT heat pump system includes a PVT array ①, a heat pump unit ⑩, and an energy storage tank ⑪. The PVT array ①, the heat pump unit ⑩, and the energy storage tank ⑪ are connected to form a heat exchange circulation system.

[0024] The three-element integrated power system includes a PVT and photovoltaic hybrid array (①, ②), a grid-connected inverter (③), an electromagnetic relay A (⑤), a rectifier (⑥), an electromagnetic relay B (⑦), an inverter (⑧), and an MCU controller (⑨).

[0025] Among them, the PVT and photovoltaic hybrid array (①, ②) constitute a subsystem, which is composed of several PVT array ① and photovoltaic hybrid array ② connected in series to form a hybrid module. The positive and negative terminals of PVT array ① are connected in series with each other, the photovoltaic hybrid array is connected with each other, and the photovoltaic hybrid array ② is connected with each other. Several hybrid modules are connected in parallel to form the PVT and photovoltaic hybrid array (①, ②). The hybrid modules are connected in parallel with the same polarity. The output voltage of the PVT and photovoltaic hybrid array (①, ②) reaches the input voltage range of the inverter.

[0026] The PVT and photovoltaic hybrid array, grid-connected inverter, and power grid are connected in series to enable the PVT and photovoltaic hybrid array to output power to the power grid. The power grid, rectifier, inverter, and heat pump unit are connected in series to enable the operation of the heat pump unit's compressor to be controlled by power supplied from the power grid. Electromagnetic relay A is connected between the output terminal of the PVT and photovoltaic hybrid array and the inverter to enable the PVT and photovoltaic hybrid array to output power to the compressor of the heat pump unit. Electromagnetic relay B is connected between the inverter and the rectifier to enable the power supply between the power grid and the compressor.

[0027] The MCU controller is connected to electromagnetic relays A and B and controls their on / off states. The MCU controller is also connected to the inverter and collects the real-time power of the inverter. The MCU controller is also connected to the PVT and photovoltaic hybrid array, and the compressor in the heat pump unit and collects the output power of the PVT and photovoltaic hybrid array and the operating power of the compressor in real time.

[0028] The PVT and photovoltaic hybrid array is composed of several hybrid modules connected in parallel; the hybrid module is composed of several PVT components and photovoltaic components connected in series, and the PVT components in the hybrid module are connected in series with each other, with PVT components and photovoltaic components connected in series with each other, and with photovoltaic components connected in series with each other through positive and negative electrodes.

[0029] The rectifier consists of six rectifier diodes arranged in a three-wire configuration, and the inverter is a single-stage inverter based on an IGBT power conversion module, and the inverter has two large capacitors.

[0030] Example 2: A control method for a ternary integrated PVT heat pump energy system, using the system described in Example 1, including: (1) If the PVT heat pump system stops operating, both electromagnetic relay A and electromagnetic relay B will be disconnected, and the PVT and photovoltaic hybrid array will generate electricity through the grid-connected inverter.

[0031] (2) When the PVT heat pump system is running, the MCU controller reads the hourly weather forecast in real time. If it is a sunny day, the electromagnetic relay A switch is closed and the electromagnetic relay B switch is opened; the compressor adaptively matches the maximum power output point of the PVT and photovoltaic hybrid array under varying irradiance conditions. If the output power of the PVT and photovoltaic hybrid array is lower than the rated operating power of the compressor, the photovoltaic DC power output by the PVT and photovoltaic hybrid array directly drives the compressor to operate at a variable frequency. If the output power of the PVT and photovoltaic hybrid array is higher than the rated operating power of the compressor, the compressor maintains its rated power operation, and the photovoltaic DC power of the PVT and photovoltaic hybrid array that exceeds the rated power of the compressor is transmitted to the grid through the grid-connected inverter. If the output power of the PVT and photovoltaic hybrid array is equal to the rated operating power of the compressor, the compressor will maintain its rated power operation. (3) When the PVT heat pump system is running, the MCU controller reads the hourly weather forecast in real time. If it is not a sunny day, the electromagnetic relay A and electromagnetic relay B switches are closed. The grid voltage is rectified into a stable DC power by the rectifier. At the same time, the operating voltage of the PVT and photovoltaic hybrid array is corrected and the constant voltage method is used to keep the PVT and photovoltaic hybrid array at the maximum power point output. If the output power of the PVT and photovoltaic hybrid array is lower than the rated operating power of the compressor, the photovoltaic DC power output by the PVT and photovoltaic hybrid array and the power grid work together to drive the compressor to maintain rated power operation. If the output power of the PVT and photovoltaic hybrid array is higher than the rated operating power, the electromagnetic relay B will be disconnected, the compressor will maintain the rated power operation, and the excess photovoltaic DC power of the PVT and photovoltaic hybrid array that exceeds the rated power of the compressor will be transmitted to the grid through the grid-connected inverter. If the output power of the PVT and photovoltaic hybrid array is equal to the rated operating power of the compressor, the compressor will maintain its rated power operation.

[0032] Furthermore, when the PVT heat pump system is operating in cooling mode, the upper limit of the PVT heat pump system's exhaust pressure is used as a limiting condition for the compressor's operating frequency. When the compressor's exhaust pressure is higher than the pressure that the PVT and photovoltaic hybrid array flow channels can withstand, the compressor's operating frequency is reduced to lower the exhaust pressure. The compressor's operating frequency is adjusted according to changes in irradiance and ambient temperature to ensure that the exhaust pressure is always lower than the upper limit.

[0033] The specific method for the compressor's adaptive frequency conversion to match the maximum power output point is as follows: The MCU controller acquires the photovoltaic power generation of the PVT and photovoltaic hybrid array and the compressor operating frequency twice, before and after the acquisition, and outputs a disturbance control signal to the inverter to cause the compressor frequency to change with a certain step period; the output power of the PVT and photovoltaic hybrid array before and after the disturbance is compared. If the power output of the PVT and photovoltaic hybrid array after the disturbance is greater than that before the disturbance, the direction of the compressor frequency disturbance of the heat pump unit remains unchanged; If the output power of the PVT and photovoltaic hybrid array after the disturbance is less than that before the disturbance, the compressor frequency of the heat pump unit will change in the opposite direction.

[0034] If the output power of the perturbed PVT and the photovoltaic hybrid array is equal, then the output power is continuously measured and compared.

[0035] To explain the above process in detail, taking a day's operation as an example, in the initial state, the grid-connected inverter ③ is always connected to the grid ④. After the sun comes out in the morning, the sun shines on the surface of the photovoltaic cells, and after the photovoltaic effect, photovoltaic DC power is generated. The DC power is inverted by the grid-connected inverter ③ into three-phase power that meets the national grid-connected power quality standards, and then sent to the grid ④. This control method is the photovoltaic DC power grid-connected mode.

[0036] When the PVT heat pump system is turned on, the MCU controller ⑨ reads the hourly weather forecast from the gateway in real time. When the weather forecast is sunny, the electromagnetic relay A⑤ is activated. The control method is that the photovoltaic DC power independently drives the compressor, and the photovoltaic DC power actively and preferentially flows into the heat pump unit ⑩ compressor.

[0037] To ensure stable operation of inverter ⑧, the output voltage levels of the PVT and photovoltaic hybrid array (①, ②) are within the input voltage range of inverter ⑧. The structure of the PVT and photovoltaic hybrid array is as follows: Figure 2 As shown, the photovoltaic array ① is connected in series with the PVT array ② to reach the input voltage range of the inverter ⑧. Multiple strings of PVT and photovoltaic modules are connected in series and parallel to form a hybrid PVT and photovoltaic array (①, ②) to further meet the power requirements of the PVT heat pump integrated energy system.

[0038] When the PVT heat pump system is turned on, the MCU controller ⑨ reads the hourly weather forecast from the gateway in real time. When the forecast for the next hour is not sunny, the control method is to use photovoltaic DC power and the power grid to jointly drive the compressor. Switch electromagnetic relays A⑤ and B⑦ are both closed. When the output power of the PVT and photovoltaic hybrid array (①, ②) is lower than the rated operating power of the compressor of the heat pump unit ⑩, the photovoltaic DC power of the PVT and photovoltaic hybrid array (①, ②) and the power grid ④ jointly drive the compressor to operate at its rated power.

[0039] When the output power of the PVT and photovoltaic hybrid array (①, ②) is higher than the rated operating power of the compressor of the heat pump unit ⑩, the compressor maintains the rated power operation, and the excess output power of the PVT and photovoltaic hybrid array (①, ②) is transmitted to the power grid through the grid-connected inverter ③.

[0040] Taking the SM572-190 photovoltaic module as an example, the maximum power point voltage is 36.5 V, the maximum power point current is 5.21 A, and the maximum power output is 190 W. The rated power of the 3HP PVT heat pump energy storage system compressor is 3.6 kW, and the heat power matching is 12 PVT modules. The three-phase power from the grid (④) is 380 V, which is rectified to 525 V by the rectifier (⑥), corresponding to 15 SM572-190 PV modules. Since the photovoltaic voltage is less affected by the environment, and the output voltage loss during the aging process of the PVT modules is not significant (<0.5%), considering the series voltage loss between photovoltaic modules, the specific implementation plan designs a single string connection of 16 modules, and finally determines 4 PVT modules. The rated power of a single string of PVT and photovoltaic is 3.04 kW. Two strings of PVT and photovoltaic are connected in parallel to form a PVT and photovoltaic hybrid array (①, ②), with a rated output power of 6.08 kW.

[0041] A hybrid PVT and photovoltaic array (①, ②) consisting of two parallel PVT and photovoltaic strings is connected to the positive and negative terminals of the inverter ③ via cables. The three-phase (380V) RST power from the grid ④ is connected to the input terminals of the rectifier module. After rectification by rectifier ⑥, the voltage is 525V. The positive and negative terminals of rectifier ⑥ are connected to the same polarity as those of inverter ③. The output terminals of inverter ③ are connected to the UVW terminals of the compressor in the heat pump unit ⑩. like Figure 3 As shown. When the control method is photovoltaic DC power independently driving the compressor of the heat pump unit ⑩, under the condition of changing solar irradiance, the MCU controller ⑨ collects the photovoltaic power generation and the operating frequency of the compressor of the heat pump unit ⑩ twice, and outputs a disturbance control signal to the inverter to realize the periodic disturbance change of the compressor frequency f(n) with a step size of Δf. The output power of the PVT and photovoltaic hybrid array (①, ②) after disturbance is compared with the output power of the PVT and photovoltaic hybrid array (①, ②) before disturbance: If the output power of the PVT and photovoltaic hybrid array (①, ②) after the disturbance is greater than that before the disturbance, it means that the direction of the disturbance signal in the previous cycle can increase the output power of the PVT and photovoltaic hybrid array (①, ②). Therefore, the direction of the frequency disturbance of the heat pump unit ⑩ compressor remains unchanged in the next cycle.

[0042] If the output power of the PVT and photovoltaic hybrid array (①, ②) after the disturbance is less than that before the disturbance, it means that the direction of the disturbance causes the output power of the photovoltaic array (①, ②) to decrease. Therefore, the frequency disturbance direction of the heat pump unit ⑩ compressor will change in the opposite direction next time.

[0043] If the output power of the two PVT and photovoltaic hybrid arrays (①, ②) is equal, then continue to detect and compare the output power.

[0044] Ultimately, the output power of the PVT and photovoltaic hybrid array (①, ②) remains at maximum at all times.

[0045] The control process of the photovoltaic DC independent drive compressor is as follows: Figure 4 As shown. For example, when the irradiance reaches 500 W / m 2 At this time, the power generation of the PVT and photovoltaic hybrid array (①, ②) is 3.04 kW. At this time, the compressor of the heat pump unit ⑩ operates at a variable frequency between 40 and 45 Hz; when the irradiance reaches 1000 W / m 2 At that time, the theoretical maximum power of the PVT and photovoltaic hybrid array (①, ②) is 6.08 kW. At this time, the rated power of the heat pump unit ⑩ compressor is 3.6kW (full load 50Hz), and the excess power generated by the PVT and photovoltaic hybrid array (①, ②) is 2.48kW and transmitted to the grid ④.

[0046] When the control method involves a combination of photovoltaic DC power and grid-driven compressor, under varying solar irradiance conditions, when the irradiance reaches 500 W / m²... 2 At this time, the theoretical power generation of the PVT and photovoltaic hybrid array (①, ②) is 3.04 kW. At this time, the rated power of the heat pump unit ⑩ compressor is 3.6 kW, and the supplementary power from the three-phase power grid ④ is 0.56 kW. When the irradiance reaches 1000 W / m²... 2 At that time, the theoretical maximum power of the PVT and photovoltaic hybrid array (①, ②) is 6.08 kW. At this time, the rated power of the heat pump unit ⑩ compressor is 3.6kW, and the excess power of the PVT and photovoltaic hybrid array (①, ②) is 2.48kW and transmitted to the grid ④.

[0047] For regions with varying irradiance resources, voltage level adaptation selection can be achieved through the following two design methods: 1) changing the number of photovoltaic modules connected; 2) adapting the photovoltaic module model, primarily considering the maximum power point voltage and maximum output power. The power supplement from the grid (④) shows a trend opposite to the output power of the PVT and photovoltaic hybrid array. Ultimately, the output power of the PVT and photovoltaic hybrid array, combined with the three-phase power from the grid (④), supplies power to the compressor.

[0048] The embodiments disclosed herein are preferred embodiments, but are not limited thereto. Those skilled in the art can readily grasp the spirit of the present invention based on the above embodiments and make different extensions and variations, but as long as they do not depart from the spirit of the present invention, they are all within the protection scope of the present invention.

Claims

1. A ternary integrated PVT heat pump energy system, comprising a PVT heat pump system and a ternary integrated power system; the PVT heat pump system consists of a PVT array, a heat pump unit, and an energy storage tank, connected by a four-way reversing valve to form a circulation system realizing cooling, heating, cold storage, and heat storage functions; the ternary integrated power system comprises a PVT and photovoltaic hybrid array, an electromagnetic relay A, a rectifier, an electromagnetic relay B, an inverter, an MCU controller, a grid-connected inverter, and a power grid; characterized in that: The PVT and photovoltaic hybrid array, grid-connected inverter, and power grid are connected in series to enable the PVT and photovoltaic hybrid array to output power to the power grid. The power grid, rectifier, inverter, and heat pump unit are connected in series to enable the operation of the heat pump unit's compressor to be controlled by power supplied from the power grid. Electromagnetic relay A is connected between the output terminal of the PVT and photovoltaic hybrid array and the inverter to enable the PVT and photovoltaic hybrid array to output power to the compressor of the heat pump unit. Electromagnetic relay B is connected between the inverter and the rectifier to enable the power supply between the power grid and the compressor. The MCU controller is connected to electromagnetic relays A and B and controls their on / off states. The MCU controller is also connected to the inverter and collects the real-time power of the inverter. The MCU controller is also connected to the PVT and photovoltaic hybrid array, and the compressor in the heat pump unit and collects the output power of the PVT and photovoltaic hybrid array and the operating power of the compressor in real time.

2. The ternary integrated PVT heat pump comprehensive energy system as described in claim 1, characterized in that: The PVT and photovoltaic hybrid array is composed of several hybrid modules connected in parallel; the hybrid module is composed of several PVT components and photovoltaic components connected in series, and the PVT components in the hybrid module are connected in series with each other, with PVT components and photovoltaic components connected in series with each other, and with photovoltaic components connected in series with each other through positive and negative electrodes.

3. The ternary integrated PVT heat pump comprehensive energy system as described in claim 1, characterized in that: The rectifier consists of six rectifier diodes arranged in a three-wire configuration, and the inverter is a single-stage inverter based on an IGBT power conversion module, and the inverter contains two capacitors.

4. A control method for a ternary integrated PVT heat pump energy system, characterized in that, Using the ternary integrated PVT heat pump integrated energy system as described in any one of claims 1 to 3, including: (1) If the PVT heat pump system stops operating, both electromagnetic relay A and electromagnetic relay B will be disconnected, and the PVT and photovoltaic hybrid array will generate electricity through the grid-connected inverter. (2) When the PVT heat pump system is running, the MCU controller reads the hourly weather forecast in real time. If it is a sunny day, the electromagnetic relay A switch is closed and the electromagnetic relay B switch is opened; the compressor adaptively matches the maximum power output point of the PVT and photovoltaic hybrid array under varying irradiance conditions. If the output power of the PVT and photovoltaic hybrid array is lower than the rated operating power of the compressor, the photovoltaic DC power output by the PVT and photovoltaic hybrid array directly drives the compressor to operate at a variable frequency. If the output power of the PVT and photovoltaic hybrid array is higher than the rated operating power of the compressor, the compressor maintains its rated power operation, and the photovoltaic DC power of the PVT and photovoltaic hybrid array that exceeds the rated power of the compressor is transmitted to the grid through the grid-connected inverter. If the output power of the PVT and photovoltaic hybrid array is equal to the rated operating power of the compressor, the compressor will maintain its rated power operation. (3) When the PVT heat pump system is running, the MCU controller reads the hourly weather forecast in real time. If it is not a sunny day, the electromagnetic relay A and electromagnetic relay B switches are closed. The grid voltage is rectified into a stable DC power by the rectifier. At the same time, the operating voltage of the PVT and photovoltaic hybrid array is corrected and the constant voltage method is used to keep the PVT and photovoltaic hybrid array at the maximum power point output. If the output power of the PVT and photovoltaic hybrid array is lower than the rated operating power of the compressor, the photovoltaic DC power output by the PVT and photovoltaic hybrid array and the power grid work together to drive the compressor to maintain rated power operation. If the output power of the PVT and photovoltaic hybrid array is higher than the rated operating power, the electromagnetic relay B will be disconnected, the compressor will maintain the rated power operation, and the excess photovoltaic DC power of the PVT and photovoltaic hybrid array that exceeds the rated power of the compressor will be transmitted to the grid through the grid-connected inverter. If the output power of the PVT and photovoltaic hybrid array is equal to the rated operating power of the compressor, the compressor will maintain its rated power operation.

5. The control method for the ternary integrated PVT heat pump energy system as described in claim 4, characterized in that: When the PVT heat pump system is operating in cooling mode, the upper limit of the PVT heat pump system's exhaust pressure is used as the limiting condition for the compressor's operating frequency. When the compressor's exhaust pressure is higher than the pressure that the PVT and photovoltaic hybrid array flow channels can withstand, the compressor's operating frequency is reduced to lower the exhaust pressure. The compressor's operating frequency is adjusted according to changes in irradiance and ambient temperature to ensure that the exhaust pressure is always lower than the upper limit.

6. The control method for the ternary integrated PVT heat pump comprehensive energy system as described in claim 4, characterized in that... The specific method for the compressor's adaptive frequency conversion to match the maximum power output point is as follows: The MCU controller acquires the photovoltaic power generation of the PVT and photovoltaic hybrid array and the compressor operating frequency twice, before and after the acquisition, and outputs a disturbance control signal to the inverter to cause the compressor frequency to change with a certain step period; the output power of the PVT and photovoltaic hybrid array before and after the disturbance is compared. If the power output of the PVT and photovoltaic hybrid array after the disturbance is greater than that before the disturbance, the direction of the compressor frequency disturbance of the heat pump unit remains unchanged; If the output power of the PVT and photovoltaic hybrid array after the disturbance is less than that before the disturbance, the compressor frequency of the heat pump unit will change in the opposite direction. If the output power of the perturbed PVT and the photovoltaic hybrid array is equal, then the output power is continuously measured and compared.

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