Floating offshore photovoltaic power generation transformer

Abstract

This invention discloses a transformer for offshore photovoltaic power generation, relating to the field of offshore photovoltaic power generation technology. It includes a transformer body and a floating platform. The transformer body is fixed to a base, and the lower end of the base is fixedly connected to the floating platform. The transformer body includes an oil tank and an internal transformer. The top of the transformer is fixedly connected to the top of the oil tank via screws, and the lower part of the transformer is connected to the bottom of the oil tank via a limiting mechanism. The oil tank does not have finned cooling; instead, a forced air cooling device dissipates heat from the transformer oil inside the tank. The floating platform is limited by a fixed limiting device. Compared to traditional offshore photovoltaic power generation transformers, this method replaces land-based or offshore platform construction with floating transformer construction, reducing the specifications of power transmission cables, eliminating the need for land area and large-scale offshore platform construction, lowering costs, and reducing requirements for the equipment installation environment.

Description

Technical Field

[0001] This invention relates to the field of transformer technology for offshore photovoltaic power generation, and in particular to a floating offshore photovoltaic power generation transformer suitable for long-distance applications. Background Technology

[0002] Currently, there are two main types of offshore photovoltaic transformers: one type is installed on land, far from the sea surface, where the low-voltage power from the inverter is transmitted to the transformer via low-voltage cables. This type uses large-section low-voltage cables, resulting in higher construction costs. The other type is located on a fixed platform on the sea surface. However, for transformers in deep-sea locations, the platform construction cost is also high. Both of these solutions suffer from high construction costs.

[0003] Offshore photovoltaic systems are affected by seabed conditions and shipping routes. Conventional 35kV voltage transmission is insufficient for long-distance power transmission due to significant energy loss in the conductors. Therefore, it is necessary to increase the transmission voltage to 66kV. This places higher demands on the insulation design of the transformers.

[0004] Offshore photovoltaics can utilize the ocean area without occupying scarce land resources. Traditional 35kV land transformers or offshore fixed platform transformers can no longer meet the development needs. Therefore, there is an urgent need to develop a new offshore photovoltaic power generation transformer to reduce power generation costs and output higher voltage. Summary of the Invention

[0005] The purpose of this invention is to provide a floating offshore photovoltaic power generation transformer, which changes the construction method from land-based or offshore platform construction to floating transformer construction, reduces the specifications of the power transmission cable, does not occupy land area or require large-scale offshore platform construction, and reduces costs.

[0006] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows: The floating offshore photovoltaic power generation transformer includes a transformer body and a floating platform. The transformer body is fixed on a base, and the lower end of the base is fixedly connected to the floating platform. The transformer body includes an oil tank and an internal transformer. The top of the transformer is fixedly connected to the top of the oil tank by a screw, and the lower part of the transformer is connected to the bottom of the oil tank by a limiting mechanism. The oil tank does not have finned cooling; the transformer oil in the oil tank is cooled by a forced air cooling device.

[0007] Furthermore, the limiting mechanism includes limiting rings and shock-absorbing pads. Four limiting rings are fixed at the bottom of the oil tank, and limiting pads with conical grooves are provided inside the limiting rings. Inverted conical fixing parts are fixedly installed at the four corners of the bottom of the transformer. The fixing parts are in contact with the limiting pads to prevent the transformer from shifting horizontally inside the oil tank. Shock-absorbing pads are provided between the bottom of the transformer and the bottom of the oil tank to reduce the vibration of the transformer inside the oil tank.

[0008] The forced air cooling device includes a radiator, an oil outlet pipe, and an oil return pipe. An oil pump is installed on the oil outlet pipe, and the oil pump is equipped with a temperature sensor. The radiator includes a fan and heat exchange tubes, which are connected to both the oil outlet and return pipes. The device also includes a controller, which is connected to the temperature sensor, oil pump, and fan circuits. When the transformer power and temperature rise increase, the flow rate of the transformer oil to the radiator and the fan speed are increased to improve heat dissipation efficiency. When the power is low, the oil flow is reduced, and the fan speed is lowered or even stopped to avoid unnecessary power loss and increase the equipment's service life.

[0009] The floating platform is also equipped with a fixed limiting device, which includes anchor chains. Multiple anchor chains are evenly distributed around the lower periphery of the floating platform. The lower ends of the anchor chains are connected to the seabed through suction cylinders. A circular float is fixedly installed at the lower end of the floating platform, and its upper end is fixedly connected to the base. A counterweight is installed at the lower end of the floating platform so that the center of gravity is below the sea level, which can resist the impact of marine environments such as typhoons.

[0010] Furthermore, as another implementation, the floating platform can be connected to other floating mechanisms via connecting rods to provide a limiting device instead of a fixed limiting device.

[0011] A square oil conservator is fixed above the oil tank and connected to it. Compared to the traditional round oil conservator, it stores more transformer oil and can better regulate the transformer oil. The high-voltage bushing is a fully insulated bushing.

[0012] Furthermore, a high-pressure nozzle is fixedly installed at the lower end of the base. The high-pressure nozzles are evenly distributed above the circular float and face the side of the circular float. They are connected to the high-pressure pump through a high-pressure pipeline. The high-pressure pump is started periodically, for example, once every half month (the time can be set according to the actual working conditions). The high-pressure water jet generated by the high-pressure nozzle can remove parasitic marine organisms.

[0013] The transformer components and floating platform components are made of C5VH high corrosion-resistant plates, which are suitable for the high salt spray environment at sea. The transformer oil has been changed from mineral oil to the latest environmentally friendly vegetable oil.

[0014] The beneficial effects of this invention are as follows: (1) The transformer is changed from being installed on land or on an offshore platform to being installed on a floating offshore platform. The installation location is flexible, does not occupy land area and does not require the construction of an offshore platform, thus reducing construction costs and installation environment requirements; (2) Change the way the transformer body is fixed in the oil tank, and there are positioning and shock absorption measures in six directions inside the oil tank; change the heat dissipation structure of the transformer to improve heat dissipation efficiency and reduce the overall footprint of the transformer. (3) Because the floating offshore photovoltaic power generation transformer can be installed close to the photovoltaic panels and inverters, it can reduce the use of large cross-section low-voltage cables and use small cross-section high-voltage cables, reduce the initial construction investment, and the increased voltage level is more conducive to the transmission of electricity, reduce line power loss, and improve power generation efficiency. (4) The center of gravity of the overall equipment is located below the sea level. Combined with the strong pulling force provided by the suction anchor that extends deep into the seabed, it can ensure the stability of the equipment in the ocean and has the characteristics of resisting the influence of typhoons, waves and ocean currents. (5) The floating platform is equipped with a cleaning device, which can regularly clean the attached marine organisms, reduce the amount of manual maintenance, improve work efficiency, and extend the service life of the equipment. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of the present invention.

[0016] Figure 2 This is a top view of the structure of an embodiment of the present invention; Figure 3 This is a schematic diagram of the transformer oil tank structure; Figure 4 for Figure 3 Enlarged view of point A in the middle; Figure 5 This is a top view of the transformer body.

[0017] 1-Transformer body, 2-Base, 3-Circular floating ring, 4-Anchor chain, 5-Suction cylinder, 6-Screw, 7-Fixing ring, 8-Shock damping pad, 9-Fixing component, 10-Limiting pad, 11-Low voltage cable, 12-High voltage cable, 13-High voltage bushing, 14-Radiator, 15-Oil pump, 16-Oil outlet pipe, 17-Oil return pipe, 18-Fan. Detailed Implementation

[0018] The present invention will be further described below with reference to the accompanying drawings: The floating offshore photovoltaic power generation transformer includes a transformer body 1 and a floating platform. The transformer body 1 is fixed on a base 2, and the lower end of the base 2 is fixedly connected to the floating platform. The transformer body 1 includes an oil tank and an internal transformer. The top of the transformer is fixedly connected to the top of the oil tank through a screw 6, and the lower part of the transformer is connected to the bottom of the oil tank through a limiting mechanism. The oil tank does not have a heat exchanger, and the transformer oil in the oil tank is cooled by a forced air cooling device.

[0019] Furthermore, each of the high and low voltage upper clamps of the transformer has four (eight in total) M30 screws 6 connected to the top cover of the oil tank. The eight M30 screws can prevent the transformer from moving vertically inside the oil tank. Each of the four corners of the lower clamp of the transformer is equipped with a φ50 inverted conical fixing piece 9. At the corresponding positions on the bottom of the oil tank, four fixing rings 7 with an inner diameter of φ134 are welded. Between the fixing rings 7 and the inverted conical fixing pieces 7 is an insulating limiting pad 10 for adjusting the fixing gap. The inverted conical fixing pieces can prevent the transformer from moving horizontally inside the oil tank. A shock-absorbing pad 8 is set between the bottom of the transformer and the bottom of the oil tank to reduce the vibration of the transformer inside the oil tank. The transformer in this embodiment serves as a step-up transformer. Compared to conventional 35kV new energy transformers, it has a higher voltage level of 66kV and a larger insulation size. The traditional internal pressure plate fixing method of new energy transformers cannot meet the usage environment on the sea surface. The transformer is prone to movement relative to the oil tank, resulting in insufficient insulation distance and thus causing the transformer to burn out. By improving the internal fixing method, it is more adaptable to the vibration environment of floating at sea.

[0020] The forced air cooling device includes a radiator 14, an oil outlet pipe 16, and an oil return pipe 17. An oil pump 15 is installed on the oil outlet pipe 16, and the oil pump 15 is equipped with a temperature sensor. The radiator 14 is equipped with a fan 18 and heat exchange tubes, which are connected to both the oil outlet pipe 16 and the oil return pipe 17. The device also includes a controller, which is connected to the temperature sensor, oil pump, and fan circuits. When the transformer power and temperature rise increase, the flow rate of the transformer oil to the radiator and the fan speed are increased to improve heat dissipation efficiency. When the power is low, the oil flow is reduced and the fan speed is lowered or even stopped to avoid unnecessary power loss and increase the service life of the equipment. By modifying the transformer's heat dissipation method, transformer fin defects are eliminated, and heat dissipation is achieved through a forced oil circulation air cooler, reducing the transformer's footprint and improving heat dissipation efficiency.

[0021] The floating platform is also equipped with a fixed limiting device, which includes anchor chains 4. Multiple anchor chains 4 are evenly distributed around the lower periphery of the floating platform. In this embodiment, six anchor chains are provided. The lower ends of the anchor chains 4 are connected to the seabed through suction cylinders 5. The suction anchor works by using underwater negative pressure to fix the anchors to the seabed and provide limiting tension to the floating platform. A circular float 3 is fixedly installed at the lower end of the floating platform. Its upper center is fixedly connected to the base 2. A fixed counterweight is installed at the lower end of the floating platform so that the center of gravity is below the sea level. The circular float 3 is connected to a support frame. The support frame converges towards the center and is fixedly connected to the lower end of the transformer mounting base. This circular float floating method can improve the overall stability of the device and reduce the impact of marine environments such as typhoons.

[0022] Furthermore, as another implementation, the floating platform can be connected to other floating mechanisms via a connecting rod to achieve a limiting connection instead of a fixed limiting device.

[0023] A square oil storage tank is fixed above the oil tank and connected to the oil tank. Compared with the traditional round oil storage tank, it can store more transformer oil and play a better role in regulating the transformer oil. The high-voltage bushing 13 is a fully insulated bushing.

[0024] Furthermore, a high-pressure nozzle is fixedly installed at the lower end of the base. The high-pressure nozzles are evenly distributed above the circular float and face the side of the circular float. They are connected to the high-pressure pump through a high-pressure pipeline. The high-pressure pump is started once every half month (the time can be set according to the actual working conditions). The high-pressure water jet generated by the high-pressure nozzle can remove parasitic marine organisms.

[0025] The transformer components and floating platform components use C5VH high-corrosion-resistant plates, adapting to the high-salt-spray environment of the sea. The transformer oil has been replaced from mineral oil with the latest environmentally friendly vegetable oil, which is biodegradable and pollution-free, ensuring that even if leakage occurs, it will not seriously impact the marine environment. Magnetic shielding and the use of high-grade silicon steel sheets reduce stray losses during transformer operation, enabling the product to meet the latest GB20052-2024 energy efficiency requirements, thus reducing unnecessary energy waste.

[0026] The transformer tank is fixed to the base by 12 evenly distributed M24 high-strength bolts around its bottom; the high-voltage bushing is a fully insulated bushing to ensure that the high-voltage insulation is not affected by the marine environment.

[0027] The electricity generated by the photovoltaic panels is converted into 0.8kV AC by the inverter, and then transmitted to the low-voltage side of the transformer via low-voltage cable 11. After transformation, it outputs 66kV high-voltage electricity, which is then transmitted to the main transformer via high-voltage cable 12. After the implementation of this product, the use of large-section low-voltage cables will be reduced, the cable area for transmitting power will be reduced, and construction costs will be reduced.

[0028] The data cited above is for illustrative purposes only. Other models, voltage levels, and products with different capacity ratios are all within the scope of protection of this patent document.

Claims

1. A floating offshore photovoltaic power generation transformer, characterized in that: It includes a transformer body and a floating platform. The transformer body is fixed on the base, and the lower end of the base is fixedly connected to the floating platform. The transformer body includes an oil tank and an internal transformer. The top of the transformer is fixedly connected to the top of the oil tank by a screw, and the lower part of the transformer is connected to the bottom of the oil tank by a limiting mechanism. The oil tank does not have a cooling plate and the transformer oil in the oil tank is cooled by a forced air cooling device.

2. The floating offshore photovoltaic power generation transformer according to claim 1, characterized in that: The limiting mechanism includes limiting rings and shock-absorbing pads. Four limiting rings are fixed at the bottom of the oil tank, and limiting pads with conical grooves are set inside the limiting rings. Inverted conical fixing parts are fixedly installed at the four corners of the bottom of the transformer. The fixing parts are in contact with the limiting pads to prevent the transformer from shifting horizontally inside the oil tank. Shock-absorbing pads are set between the bottom of the transformer and the bottom of the oil tank to reduce the vibration of the transformer inside the oil tank.

3. The floating offshore photovoltaic power generation transformer according to claim 1, characterized in that: The forced air cooling device includes a radiator, an oil outlet pipe, and an oil return pipe. The oil outlet pipe is equipped with an oil pump, which is connected to a temperature sensor. The radiator is equipped with a fan and heat exchange tubes, which are connected to the oil outlet pipe and the oil return pipe respectively. The device is also equipped with a controller, which is connected to the temperature sensor, the oil pump, and the fan circuit respectively. When the transformer power and temperature rise increase, the internal transformer oil flow rate to the radiator and the fan speed are increased to improve the heat dissipation efficiency.

4. The floating offshore photovoltaic power generation transformer according to claim 1, characterized in that: The floating platform is also equipped with a fixed limiting device, which includes anchor chains. Multiple anchor chains are evenly distributed around the lower periphery of the floating platform. The lower ends of the anchor chains are connected to the seabed through suction cylinders. A circular float is fixedly installed at the lower end of the floating platform, and its upper end is fixedly connected to the base. A counterweight is installed at the lower end of the floating platform so that the center of gravity is below the sea level, which can resist the impact of marine environments such as typhoons.

5. The floating offshore photovoltaic power generation transformer according to claim 1, characterized in that: The aforementioned floating platform can be limited by connecting it to other floating mechanisms via connecting rods.

6. The floating offshore photovoltaic power generation transformer according to claim 1, characterized in that: A square oil storage tank is fixed above the oil tank and connected to the oil tank; the high-voltage bushing is a fully insulated bushing.

7. The floating offshore photovoltaic power generation transformer according to claim 4, characterized in that: A high-pressure nozzle is fixedly installed at the lower end of the base. The high-pressure nozzles are evenly distributed above the circular float ring, with the nozzles facing the side of the circular float ring. They are connected to a high-pressure pump through a high-pressure pipeline, and the high-pressure pump is started periodically.

8. The floating offshore photovoltaic power generation transformer according to claim 1, characterized in that: The transformer components and floating platform components are made of C5VH high corrosion-resistant plates; the transformer oil is vegetable oil.

Images