Heat dissipation system of energy storage converter

Abstract

The invention relates to the field of converters, in particular to a heat dissipation system of an energy storage converter. Comprising a liquid cooling unit, a power unit, a liquid cooling reactor and a flow distribution unit, the power unit comprises an IGBT module and a power unit liquid cooling plate, the IGBT module is in close contact with the power unit liquid cooling plate, and a power unit cooling flow channel is arranged in the power unit liquid cooling plate; the liquid cooling electric reactor comprises an electric reactor coil and an electric reactor liquid cooling plate, the electric reactor coil is tightly attached to the electric reactor liquid cooling plate, an electric reactor cooling flow channel is arranged in the electric reactor liquid cooling plate, and the power unit cooling flow channel and the electric reactor cooling flow channel are both communicated with the liquid cooling unit through pipelines; the flow distribution unit is arranged between the power unit and the reactor and intelligently distributes the optimal flow in a preset mode according to the thermal load difference between the power unit water cooling plate and the reactor liquid cooling plate. According to the invention, uniform-temperature cooling of a high-heat-flux IGBT and deep heat conduction of a large-volume reactor winding can be realized, and mutual interference between cooling loops of the IGBT and the reactor winding can be avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of converter, in particular to a heat dissipation system of energy storage converter. BACKGROUND

[0002] The energy storage converter is a key device for ensuring the quality of power transmission and dynamic characteristics control of the energy storage system, can realize the bidirectional flow of energy, can control the charging and discharging process of the battery, can convert AC and DC, and can directly power the AC load in the absence of power grid. The energy storage converter can effectively regulate the power resources in the smart grid, well balance the power difference between day and night and different seasons, and ensure the safety of the power grid. The energy storage converter can be applied in different occasions such as grid-connected system, island system and hybrid system, and is suitable for various application occasions requiring dynamic energy storage. The core of the energy storage converter is the power unit and the filter. In the working process of the energy storage converter, a large amount of heat is generated in the electric reactor part of the power unit and the filter, causing the temperature to rise. The excessively high temperature will cause the semiconductor devices in the power unit to burn out, resulting in the failure of the converter to work normally, and even cause a fire. Therefore, for the energy storage converter, it is of great engineering significance and economic value to design a cabinet structure that is conducive to heat dissipation.

[0003] The heat dissipation methods of current energy storage converters can be divided into forced air cooling heat dissipation method and liquid cooling heat dissipation method. The forced air cooling heat dissipation method is characterized by using air as the cooling medium, blowing air through the energy storage converter components through a fan or the like, and using the principle of convective heat transfer to take away the heat. The liquid cooling heat dissipation method is characterized by using cooling liquid as the cooling medium, closely attaching the water cooling plate to the surface of the heat generating components, and taking away the heat through the principles of convective heat transfer and conductive heat transfer. However, the above two types of heat dissipation methods have certain limitations. For the forced air cooling heat dissipation method, air cooling circulation means that air exchange with the outside world is needed, so air inlets and outlets for air exchange with the outside world are needed, which reduces the protection level of the converter, and due to the influence of heat dissipation efficiency, it is difficult to meet the heat dissipation requirements of high-power energy storage converters. At present, the liquid cooling heat dissipation technology for power units is relatively mature, but there is a lack of effective liquid cooling heat dissipation means for reactors. Therefore, the current common heat dissipation design scheme for energy storage converters is liquid cooling heat dissipation for power units and air cooling heat dissipation for reactors, and the heat dissipation systems of the two are independent of each other. At the same time, if the reactor is to be liquid cooled, a new liquid cooling circuit will have to be introduced, increasing the difficulty of device assembly. The fundamental reason for the inability to integrate the design of the power unit and reactor heat dissipation system is that the thermal characteristics of the power unit and the reactor are different. The power unit has the characteristic of local high heat flux density. The coil of the reactor is large and the internal space is narrow, causing internal heat accumulation. Therefore, a compact and efficient liquid cooling system needs to be designed, which can meet the uniform cooling of high heat flux density IGBT and the deep heat conduction of large volume reactor windings, and avoid mutual interference between the cooling circuits of the two. Thus, a general heat dissipation solution is provided for the design of large-capacity energy storage converters, simplifying the production and installation difficulty, and promoting the upgrading of energy storage converter products. SUMMARY

[0004] The present application aims to solve the technical problems of the current energy storage converter liquid cooling scheme, which is caused by the large difference in thermal characteristics between the power module and the filter reactor, resulting in a large separate heat dissipation system, complex piping, difficult cooling efficiency, and difficult maintenance. A highly integrated system is provided, which can efficiently cool two types of heterogeneous heat sources through adaptive flow distribution and targeted flow channel design.

[0005] In order to solve the technical problem, the technical scheme adopted by the present application is: a heat dissipation system of an energy storage converter, comprising a liquid cooling unit, a power unit, a liquid cooled reactor and a flow distribution unit, the power unit comprises an IGBT module and a power unit liquid cooling plate, the IGBT module is arranged on the surface of the power unit liquid cooling plate and is in close contact with the power unit liquid cooling plate, and the power unit liquid cooling plate is provided with a power unit cooling flow channel; the liquid cooled reactor comprises a reactor coil and a reactor liquid cooling plate, the reactor coil is in close contact with the reactor liquid cooling plate, and the reactor liquid cooling plate is provided with a reactor cooling flow channel, the power unit cooling flow channel and the reactor cooling flow channel are connected with the liquid cooling unit through pipelines; the cross-sectional areas of the power unit cooling flow channel and the reactor cooling flow channel are A1 and A2 respectively, the total lengths of the power unit cooling flow channel and the reactor cooling flow channel are L1 and L2 respectively, the flow resistance coefficients of the power unit cooling flow channel and the reactor cooling flow channel are R1 and R2 respectively, A1>A2, L1

[0006] Further, the power unit cooling flow channel is a straight-through flow channel or a parallel flow channel, the straight-through flow channel refers to a flow channel without branches in the middle, and the parallel flow channel is a flow channel with branches.

[0007] Further, the reactor cooling flow channel is a serpentine flow channel with multiple turns.

[0008] Further, the multi-sided reactor liquid cooling plate surrounds a polygon, and the reactor winding is located in the polygonal reactor liquid cooling plate.

[0009] Further, the liquid flow reactor further comprises a cooling liquid return pipeline, a cooling liquid inlet pipeline and a liquid cooling plate connecting pipeline, the multi-sided reactor liquid cooling plate is connected through the liquid cooling plate connecting pipeline, and the cooling liquid inlet pipeline and the cooling liquid return pipeline are connected between the reactor liquid cooling plate and the liquid cooling unit.

[0010] Further, the flow distribution control module works in an intelligent mode, and the temperature of the power unit IGBT module and the temperature of the reactor winding are collected in real time, and the opening degrees of the adjusting valve I and the adjusting valve II are controlled based on the temperature of the power unit IGBT module and the temperature of the reactor winding.

[0011] Further, the flow distribution control module works in a preset mode, the best opening degrees of the adjusting valve I and the adjusting valve II are obtained through pre-period thermal simulation and test of the equipment, and then the adjusting valve I and the adjusting valve II are set at the best opening degrees.

[0012] Further, the liquid cooling unit, the power unit, the liquid cooled reactor and the flow distribution unit are arranged in the energy storage converter cabinet, the liquid cooling unit is assembled at the top of the cabinet frame, and the power unit and the liquid cooled reactor are connected through pipelines, the power unit is assembled in the upper cavity of the cabinet frame, and the power unit and the liquid cooled reactor are connected through copper bars, the liquid cooled reactor is assembled in the lower cavity of the cabinet frame, and the flow distribution unit is arranged between the power unit and the liquid cooled reactor.

[0013] Further, the reactor liquid cooling plate is made of heat-conducting insulating material.

[0014] The application has the following advantages: 1. High integration and high space utilization. Through the innovative integrated distribution unit and the optimized parallel pipeline layout, compared with the traditional two independent circuits, the pipeline length and external joints are reduced by 30%, and the internal structure of the cabinet is more compact.

[0015] 2. Differentiated cooling plates designed for different heat source characteristics, cooperating with the flow distribution unit, ensure the maximum utilization of the cooling liquid efficiency. Based on thermal simulation and prototype test results, under typical working conditions, the overall thermal resistance of the system is reduced by about 20%.

[0016] 3. The two pipelines from the distribution unit are connected to the power unit cooling flow channel and the reactor cooling flow channel in parallel and shortest path. The return water pipeline also converges in the shortest path to form a compact closed-loop system of "one-to-two, two-to-one", which maximizes the reduction of pipeline length and joint number.

[0017] 4. The flow distribution mechanism avoids local overheating caused by uneven flow distribution, the system temperature field is more uniform, and the service life and reliability of the key devices (such as IGBT) are improved.

[0018] 5. The modular flow channel distribution unit and the standardized interface design reduce the assembly difficulty and facilitate subsequent isolation and maintenance of single cooling branch. DETAILED DESCRIPTION

[0019] Figure 1 It is a schematic diagram of the overall structure of the energy storage converter cabinet; Figure 2 It is a schematic diagram of the structure of the power unit; Figure 3 It is a schematic diagram of the three-dimensional structure of the liquid cooled reactor; Figure 4 It is a schematic diagram of the front view structure of the liquid cooled reactor; Figure 5 It is a schematic diagram of the side view structure of the liquid cooled reactor; Figure 6 It is a schematic diagram of the structure of the flow distribution unit; Figure 7This is a schematic diagram of the cooling flow path for the power unit; Figure 8 This is a schematic diagram of the reactor cooling flow path; In the diagram: 1. Liquid-cooled unit, 2. Cabinet frame, 3. Power unit, 4. Flow distribution unit, 5. Liquid-cooled reactor, 31. IGBT module, 32. Power unit liquid-cooled plate, 33. Power unit cooling channel, 41. Regulating valve I, 42. Regulating valve II, 43. Coolant inlet, 44. Coolant outlet I, 45. Coolant outlet II, 51. Coolant return pipe, 52. Reactor base plate, 53. Coolant inlet pipe, 54. Liquid-cooled plate connecting pipe, 55. Reactor liquid-cooled plate, 56. Reactor cooling channel. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0021] Example 1 This embodiment discloses a heat dissipation system for an energy storage converter. Its core components are: a liquid-cooled chiller unit, two differently designed cooling channels, and a flow distribution unit for connection and control. The heat dissipation system described in this embodiment includes a liquid-cooled chiller unit 1, a power unit 3, a liquid-cooled reactor 5, and a flow distribution unit 4, as follows: Figure 1 As shown, the liquid-cooled unit 1, power unit 3, liquid-cooled reactor 5, and flow distribution unit 4 are installed inside the energy storage converter cabinet. The liquid-cooled unit 1 is bolted to the top of the cabinet frame 2 and connected to the power unit 3 and liquid-cooled reactor 5 through pipes. The power unit 3 is bolted to the upper cavity inside the cabinet frame 2 and connected to the liquid-cooled reactor 5 through copper busbars. The liquid-cooled reactor 5 is bolted to the lower cavity inside the cabinet frame 2. The flow distribution unit 4 is located between the power unit 3 and the liquid-cooled reactor 5. The flow distribution unit 4 is equipped with a regulating valve based on the feedback of the power unit IGBT module temperature and the reactor winding temperature, or it is designed as a flow-diverting cavity structure with a fixed flow resistance ratio. The purpose is to intelligently or pre-determine the optimal flow rate according to the difference in heat load between the liquid-cooled plates of the power unit and the reactor.

[0022] like Figure 2 As shown, the power unit 3 includes an IGBT module 31 and a power unit liquid cooling plate 32. The IGBT module 31 is fixedly connected to the surface of the power unit liquid cooling plate 32 and is in close contact with the surface of the liquid cooling plate. The power unit liquid cooling plate 32 has a straight or parallel power unit cooling channel 33 with a large cross-sectional area, short channel length, and low flow resistance coefficient. The coolant exchanges heat with the IGBT module 31 on the surface through the power unit cooling channel 33 via convection. Figure 7The power unit cooling flow channel 33 is serpentine in the design form of the flow channel in this embodiment, but has fewer turns, a larger cross-sectional area, a shorter flow channel length, and a smaller flow resistance. The power unit is used for power conversion and is one of the cooling objects of the liquid cooling unit. The flow channel length in the power unit liquid cooling plate 32 is calculated and designed according to the actual heat dissipation requirement of the IGBT module, that is, under the premise of controlling the turbulent flow state of the cooling liquid, according to the actual heat power and working temperature range of the IGBT module, in combination with the actual working parameter limit of the liquid cooling unit 1, the number of turns is increased (when the heat power is large), so as to increase the flow resistance of the flow channel, reduce the thermal resistance between the cooling liquid and the IGBT, improve the heat dissipation capacity, and the like. This type of flow channel can reduce the flow resistance of the cooling liquid. Under the same pump power, the flow rate of the cooling liquid flowing through the flow channel is larger, so that under the condition of the same total heat absorption, the temperature rise of the cooling liquid is smaller, so as to ensure that the cooling liquid temperature at the inlet and outlet of the flow channel is almost the same, and the cooling liquid in the entire flow channel is in a relatively close low temperature state, so that uniform cooling can be performed on the contact area of all the liquid cooling plates and the IGBT modules, and the uniformity of the power unit is improved.

[0023] As shown in FIGS. Figure 3 , 4 , 5, the liquid-cooled reactor 5 includes a cooling liquid return pipeline 51, a reactor base plate 52, a cooling liquid inlet pipeline 53, a liquid cooling plate connecting pipeline 54, and a reactor liquid cooling plate 55. The reactor winding is mounted on the reactor base plate 52, and the reactor liquid cooling plate 55 is mounted on the reactor base plate by bolts and is in close contact with the surface of the reactor winding. The cooling liquid return pipeline 51 and the cooling liquid inlet pipeline 53 are connected with the reactor liquid cooling plate 55 through standard pipe joints. The reactor liquid cooling plate 55 has a serpentine reactor cooling flow channel 56 inside, which has a smaller cross-sectional area, a longer total flow channel length, and multiple turns to strengthen the turbulence, and is mounted in close contact with the surface of the reactor winding for heat dissipation. Figure 8 This design form of the flow channel is shown. The reactor cooling flow channel 56 has more turns and a smaller pipe diameter, thereby having a larger flow resistance. In this embodiment, four liquid cooling plates are provided, which are sequentially connected into a rectangle and are in communication with each other through the liquid cooling plate connecting pipeline 54 and the standard pipe joint. The liquid-cooled reactor is used for filtering in an alternating current circuit and is one of the cooling objects of the liquid cooling unit. The main function of the flow channel in the reactor liquid cooling plate 55 is to greatly increase the heat exchange area and the cooling liquid residence time, to enhance the fluid disturbance, to improve the heat exchange coefficient, to perform local extreme heat dissipation in the narrow area around the reactor, and to maximize the use of the space around the winding, thereby being beneficial to good heat dissipation of the winding. The reactor liquid cooling plate is preferably made of a heat-conducting insulating material, so as to ensure close contact and insulation with the surface of the winding and to realize deep heat conduction of the large-volume heat source.

[0024] The cross-sectional areas of the power unit cooling flow channel and the reactor cooling flow channel are A1 and A2 respectively, the total lengths of the power unit cooling flow channel and the reactor cooling flow channel are L1 and L2 respectively, the flow resistance coefficients of the power unit cooling flow channel and the reactor cooling flow channel are R1 and R2 respectively, A1>A2, L1

[0025] As shown in Figure 6 The flow distribution unit 4 includes a flow distribution control module, a regulating valve I 41, a regulating valve II 42, a cooling liquid inlet 43, a cooling liquid outlet I 44, a cooling liquid outlet II 45, the cooling liquid inlet 43 is connected with the cooling liquid outlet of the liquid cooling unit 1, the cooling liquid outlet I 44 is connected with the power unit cooling flow channel 33, the cooling liquid outlet II 45 is connected with the reactor cooling flow channel 56, the regulating valve I 41 is located on the pipeline between the cooling liquid inlet 43 and the cooling liquid outlet I 44, and is used for controlling the flow size of the power unit cooling circuit, the regulating valve II 42 is located on the pipeline between the cooling liquid inlet 43 and the cooling liquid outlet II 45, and is used for controlling the flow size of the reactor cooling circuit. The flow distribution control module is located inside the integrated flow channel distribution unit, intelligently or presetly distributes the flow of the regulating valve I 42 and the regulating valve II 42 according to the thermal load difference of the power unit and the reactor. When the flow distribution control module works in the intelligent mode, one working method is that the outlet temperatures of the two sets of cooling circuits are collected as feedback signals, and the opening degrees of the regulating valve I 41 and the regulating valve II 42 are adjusted dynamically. When the flow distribution control module works in the preset mode, the best opening degrees of the regulating valves of each circuit are obtained through the pre-period thermal simulation and test of the equipment. In the embodiment, the power unit cooling circuit and the reactor cooling circuit are connected in parallel, the flow of the two circuits is controlled by the regulating valve I 41 and the regulating valve II 42 respectively, and the control is simple. Moreover, the flow distribution unit 4 is located between the power unit 3 and the liquid-cooled reactor 5, and can be connected with the power unit cooling flow channel and the reactor cooling flow channel in parallel and the shortest path. The backwater pipeline also converges in the shortest path, forms a compact closed-loop system of “one-to-two and two-to-one”, and maximally reduces the pipeline length and the number of joints.

[0026] The structural design of the application can effectively control the temperature of the core power electronic components in the energy storage converter according to the thermal characteristics of different power electronic components, realize efficient heat dissipation of the power electronic converter, and make the internal structure of the energy storage converter compact, save internal space, and improve the single-machine power density of the energy storage converter.

[0027] The above description is only the basic principle and preferred embodiment of the application, and the improvements and replacements made by the person skilled in the art according to the application belong to the protection scope of the application.

Claims

1. A heat dissipation system for an energy storage converter, characterized in that: The system includes a liquid-cooled chiller, a power unit, a liquid-cooled reactor, and a flow distribution unit. The power unit comprises an IGBT module and a liquid-cooled plate. The IGBT module is mounted on the surface of the liquid-cooled plate and in close contact with it. The liquid-cooled plate contains cooling channels. The liquid-cooled reactor includes a reactor coil and a liquid-cooled plate. The reactor coil is mounted close to the liquid-cooled plate, and the liquid-cooled plate contains cooling channels. Both the power unit cooling channels and the reactor cooling channels are connected to the liquid-cooled chiller via pipes. The power unit cooling channels and the reactor... The cross-sectional areas of the cooling channels are A1 and A2, respectively. The total lengths of the cooling channels of the power unit and the reactor are L1 and L2, respectively. The flow resistance coefficients of the cooling channels of the power unit and the reactor are R1 and R2, respectively. A1 > A2, L1 < L2, R1 < R2. The flow distribution unit includes a flow distribution control module, regulating valve I and regulating valve II. Regulating valve I and regulating valve II are respectively installed on the pipelines between the cooling channels of the power unit and the cooling channels of the reactor and the liquid-cooled unit. The flow distribution control module is connected to regulating valve I and regulating valve II.

2. The heat dissipation system of the energy storage converter according to claim 1, characterized in that: The power unit cooling channel can be a straight-through channel or a parallel channel.

3. The heat dissipation system of the energy storage converter according to claim 1, characterized in that: The reactor cooling channel is a serpentine channel with multiple bends.

4. The heat dissipation system of the energy storage converter according to claim 1, characterized in that: The liquid cooling plates of the multifaceted reactor form a polygon, and the reactor windings are located inside the polygonal reactor liquid cooling plates.

5. The heat dissipation system of the energy storage converter according to claim 4, characterized in that: The liquid flow reactor also includes a coolant return pipe, a coolant inlet pipe, and a liquid cooling plate connecting pipe. The liquid cooling plates of the multi-faceted reactor are connected through the liquid cooling plate connecting pipe. The coolant inlet pipe and the coolant return pipe are connected between the reactor liquid cooling plate and the liquid cooling unit.

6. The heat dissipation system of the energy storage converter according to claim 1, characterized in that: The flow distribution control module operates in intelligent mode, collecting the temperature of the power unit IGBT module and the reactor winding in real time, and controlling the opening of regulating valve I and regulating valve II based on the return flow temperature.

7. The heat dissipation system of the energy storage converter according to claim 1, characterized in that: The flow distribution control module operates in a preset mode. It obtains the optimal opening degree of regulating valve I and regulating valve II through preliminary thermal simulation and testing of the equipment, and then sets regulating valve I and regulating valve II to the optimal opening degree.

8. The heat dissipation system of the energy storage converter according to claim 1, characterized in that: The liquid-cooled unit, power unit, liquid-cooled reactor, and flow distribution unit are installed inside the energy storage converter cabinet. The liquid-cooled unit is mounted on the top of the cabinet frame and is connected to the power unit and liquid-cooled reactor through pipes. The power unit is mounted in the upper cavity inside the cabinet frame and is connected to the liquid-cooled reactor through copper busbars. The liquid-cooled reactor is mounted in the lower cavity inside the cabinet frame. The flow distribution unit is located between the power unit and the liquid-cooled reactor.

9. The heat dissipation system of the energy storage converter according to claim 1, characterized in that: The reactor liquid cooling plate is made of thermally conductive and insulating material.

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