Frequency converter cooling system and method

Abstract

The invention relates to a frequency converter cooling system and method.The frequency converter cooling system comprises a frequency converter (1) and a frequency converter cabinet, the frequency converter cabinet comprises a cabinet body (2) and a cabinet door (3), the frequency converter (1) is arranged on the rear side of the cabinet body (2), a cooling fan (4) and a controller (7) are further arranged on the rear side of the cabinet body (2), and the controller (7) is connected with the cooling fan (4); the controller (7) is used for controlling starting and stopping of the cooling fan (4), an air inlet (5) is formed in the cabinet door (3), and detachable filter screens (6) are arranged on the cooling fan (4) and the air inlet (5). Compared with the prior art, the cooling effect of the cooling frequency converter is improved, and the cooling requirement and the energy-saving requirement under the severe working condition can be met.

Description

Technical Field

[0001] The present invention relates to the technical field of inverter cooling, and in particular to an inverter cooling system and method. Background Art

[0002] Conventional inverter cabinets typically use fixed louvers combined with axial fans for forced ventilation to cool the inverter. However, in actual operation, especially in summer, the existing cooling fans alone are insufficient to mitigate high temperatures within the inverter cabinet. To prevent overheating, it's necessary to keep the cabinet door open and install an additional axial fan to directly blow air onto the inverter.

[0003] The fan is installed on the side of the inverter cabinet. For example, patent application CN206195598U discloses an inverter heat dissipation structure including a housing, an axial fan is provided on the top of the housing, air duct guide plates are provided on both sides of the axial fan mounting bracket, and a radiator is provided at a position opposite to the two air duct guide plates. The radiator is opposite to the heating component mounting plate. A first air inlet is provided at the bottom of the radiator, and a second air inlet is provided at a position corresponding to the terminal on the bottom of the housing. Cooling air enters the housing through the first air inlet, the second air inlet, and the side air inlet. The flow of cooling air carries the heat generated inside the inverter. The first air inlet is a louver, which is opposite to the radiator. The original intention was to cool the inverter by forming an airflow through axial suction, but the actual air duct is blocked by the inverter body, resulting in poor gas flow and a greatly reduced cooling effect.

[0004] On the other hand, the air inlet adopts a fixed louver structure. If there is no separate inverter room, it is very easy for dust to accumulate at the air inlet, causing further blockage of the air duct and further reducing the cooling effect. Summary of the Invention

[0005] The purpose of the present invention is to provide a frequency converter cooling system and method in order to overcome the above-mentioned defects in the prior art, thereby improving the cooling effect of the frequency converter.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] A frequency converter cooling system comprises a frequency converter (1) and a frequency converter cabinet, wherein the frequency converter cabinet comprises a cabinet body (2) and a cabinet door (3), wherein the frequency converter (1) is arranged on the rear side of the cabinet body (2), and a cooling fan (4) and a controller (7) are further arranged on the rear side of the cabinet body (2), wherein the controller (7) is connected to the cooling fan (4), and the controller (7) is used to control the start and stop of the cooling fan (4) according to the ambient temperature in the frequency converter cabinet, wherein the cabinet door (3) is provided with an air inlet (5), and the cooling fan (4) and the air inlet (5) are provided with a detachable filter (6).

[0008] Furthermore, the cabinet door (3) is connected to the cabinet body (2) via a hinge.

[0009] Furthermore, the size of the cooling fan (4) is matched with the size of the air inlet (5).

[0010] Furthermore, the cooling fan (4) includes a first cooling fan (401) and a second cooling fan (402), and the first cooling fan (401) and the second cooling fan (402) are symmetrically arranged on the rear side of the cabinet body (2) on the other side of the inverter (1).

[0011] Furthermore, the air inlet (5) comprises a first air inlet (501) and a second air inlet (502), and the first air inlet (501) and the second air inlet (502) are symmetrically arranged on the cabinet door (3) in an upper and lower direction.

[0012] Furthermore, when the cabinet door (3) is closed, the axis of the first cooling fan (401) coincides with the axis of the first air inlet (501), thereby forming a first cooling air duct, and the axis of the second cooling fan (402) coincides with the axis of the second air inlet (502), thereby forming a second cooling air duct.

[0013] Furthermore, the controller (7) includes a first cooling fan (401) control circuit and a second cooling fan (402) control circuit, the control circuit of the first cooling fan (401) includes an automatic start-stop control circuit and a manual start-stop control circuit, the automatic start-stop control circuit and the manual start-stop control circuit are connected through a switching switch, and the automatic start-stop control circuit of the first cooling fan (401) is provided with an inverter operation indication Y, a thermocouple RJ1 and a relay K1; the control circuit of the second cooling fan (402) includes an automatic start-stop control circuit, a manual start-stop control circuit, a normally closed contact circuit of the power contactor K1 of the first cooling fan 401 and a thermostat auxiliary contact WJ circuit, the automatic start-stop control circuit and the manual start-stop control circuit are connected through a switching switch, and the automatic start-stop control circuit of the second cooling fan (402) is provided with a time relay T, a contactor K2 and a thermocouple RJ2.

[0014] Furthermore, the switch is provided with 6 contacts. When contact ① and contact ⑥ are connected, it is the manual start-stop position; when contact ② and contact ⑤ are connected, it is the stop position; when contact ③ and contact ④ are connected, it is the automatic start-stop position.

[0015] Furthermore, a slide groove is provided on the cooling fan (4) and the air inlet (5), the width of the slide groove matches the thickness of the detachable filter (6), and the detachable filter (6) can be disassembled and installed through the slide groove.

[0016] According to another aspect of the present invention, a method for cooling a frequency converter is provided, wherein the frequency converter is cooled by using the above-mentioned frequency converter cooling system, and the method comprises the following steps:

[0017] The switching switch of the control circuit of the first cooling fan (401) and the second cooling fan (402) is switched to the connection of contact ③ and contact ④, so that the automatic start-stop circuit of the first cooling fan (401) and the second cooling fan (402) is connected. When the frequency converter 1 starts to run, the auxiliary contact of the thermocouple RJ1 is turned on, the relay K1 is energized, and the first cooling fan (401) automatically starts to cool the frequency converter cabinet. At the same time, the auxiliary contact of the thermocouple RJ2 is turned on, the contactor K2 is disconnected, and the second cooling fan (402) stops running.

[0018] When the ambient temperature in the inverter cabinet reaches the set temperature t1 of the thermostat, the thermostat auxiliary contact WJ is closed, the time relay T is energized, the contact T is closed after a delay, the contact K2 is energized, and the second cooling fan (402) is started;

[0019] When the ambient temperature in the inverter cabinet drops to the thermostat setting value t2, the thermostat auxiliary contact WJ is disconnected, the time relay T loses power, its normally open contact T is disconnected, the contactor K2 is opened, and the second cooling fan (402) stops running, completing the cooling of the inverter 1.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. The present invention forms a cooling air duct by arranging a cooling fan next to the inverter on the rear side of the inverter cabinet and correspondingly arranging an air inlet on the inverter cabinet door, thereby avoiding the disadvantage of poor air duct due to the air inlet being blocked by the inverter. The cooling air duct of the present invention is basically free of obstacles, can efficiently cool the inverter, and improves the cooling effect of the inverter.

[0022] 2. The present invention sets a controller on the rear side of the inverter cabinet, connects the controller to the first cooling fan and the second cooling fan, uses the second cooling fan as a backup fan, and controls the start and stop of the first cooling fan and the second cooling fan according to the ambient temperature in the inverter cabinet through the controller, thereby solving the problem that when the ambient temperature in the inverter cabinet is high or the inverter is running at high output, even if the air duct is unobstructed, the temperature in the inverter cabinet is still high. The cooling fan can be set to start and stop automatically or manually, meeting energy-saving requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a front view of a cabinet of a frequency converter cooling system proposed by the present invention;

[0024] Figure 2 This is a left side view of a cabinet of a frequency converter cooling system proposed by the present invention;

[0025] Figure 3 This is a schematic diagram of the structure of the detachable filter on the cooling fan;

[0026] Figure 4 This is a schematic diagram of the structure of the detachable filter on the air inlet;

[0027] Figure 5 is a control circuit diagram of the first cooling fan;

[0028] Figure 6 is a control circuit diagram of the second cooling fan;

[0029] Figure 7 Schematic diagram of the structure of the switch QK.

[0030] Legend: 1. Inverter; 2. Cabinet body; 3. Cabinet door; 4. Cooling fan; 401. First cooling fan; 402. Second cooling fan; 5. Air inlet; 501. First air inlet; 502. Second air inlet; 6. Removable filter; 7. Controller. DETAILED DESCRIPTION

[0031] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0032] Example 1

[0033] This embodiment provides a frequency converter cooling system, including a frequency converter 1 and a frequency converter cabinet, wherein the frequency converter cabinet includes a cabinet body 2 and a cabinet door 3, and the cabinet door 3 is connected to the cabinet body 2 via a hinge. Figure 1As shown, the inverter 1 is set at the rear side of the cabinet body 2, and the cabinet body 2 is also provided with a cooling fan 4 and a controller 7. The controller 7 is connected to the cooling fan 4 and is used to control the start and stop of the cooling fan 4 according to the ambient temperature inside the inverter cabinet. Figure 2 As shown, the cabinet door 3 is provided with an air inlet 5. The size of the cooling fan 4 is matched with the size of the air inlet 5.

[0034] like Figure 3 As shown, a detachable filter 6 is provided on the cooling fan 4. Figure 4 As shown, the air inlet 5 is also provided with a removable filter 6. A chute is provided on the cooling fan 4 and the air inlet 5. The width of the chute matches the thickness of the removable filter 6, and the chute allows for removal and installation of the removable filter 6. By providing the removable filter 6 on the cooling fan 4 and the air inlet 5 instead of a fixed louver, maintenance and cleaning are facilitated, solving the problem of poor air flow caused by dust accumulation and blockage of the air inlet and outlet due to high dust levels on site.

[0035] The cooling fan 4 includes a first cooling fan 401 and a second cooling fan 402 . The first cooling fan 401 and the second cooling fan 402 are symmetrically arranged on the rear side of the cabinet body 2 on the other side of the inverter 1 .

[0036] The air inlet 5 includes a first air inlet 501 and a second air inlet 502 , and the first air inlet 501 and the second air inlet 502 are symmetrically arranged on the cabinet door 3 from top to bottom.

[0037] When the cabinet door 3 is closed, the axis of the first cooling fan 401 coincides with the axis of the first air inlet 501, forming a first cooling duct. The axis of the second cooling fan 402 coincides with the axis of the second air inlet 502, forming a second cooling duct. This improved duct design provides a smoother duct, eliminating the problem of air inlets being blocked by the inverter and resulting in a blocked duct. The duct is essentially free of obstructions, effectively cooling the inverter.

[0038] The controller 7 includes a control circuit for a first cooling fan 401 and a control circuit for a second cooling fan 402. The control circuit for the first cooling fan 401 includes an automatic start-stop control circuit and a manual start-stop control circuit, which are connected via a switching switch. The automatic start-stop control circuit of the first cooling fan 401 is provided with an inverter operation indicator Y, a thermocouple RJ1, and a relay K1. The control circuit for the second cooling fan 402 includes an automatic start-stop control circuit, a manual start-stop control circuit, a normally closed contact circuit of the power contactor K1 of the first cooling fan 401, and a thermostat auxiliary contact WJ circuit. The automatic start-stop control circuit and the manual start-stop control circuit are connected via a switching switch. The automatic start-stop control circuit of the second cooling fan 402 is provided with a time relay T, a contactor K2, and a thermocouple RJ2.

[0039] Cooling fan 4 can be started and stopped in either automatic or manual modes. Using a cooling fan that can switch between automatic and manual modes can meet cooling and energy conservation requirements in harsh operating conditions. When inverter 1 begins operation, first cooling fan 401 starts to cool the inverter cabinet. When the ambient temperature inside the inverter cabinet exceeds the preset temperature of inverter 1, second cooling fan 402 automatically turns on to cool the cabinet. Second cooling fan 402 is in automatic start-stop mode.

[0040] like Figure 5 As shown, there are 6 contacts on the transfer switch. When contact ① and contact ⑥ are connected, it is the manual start-stop position, when contact ② and contact ⑤ are connected, it is the stop position, and when contact ③ and contact ④ are connected, it is the automatic start-stop position.

[0041] The control circuit of the first cooling fan 401 is as follows Figure 6As shown, K1 represents the power contactor for first cooling fan 401, along with its corresponding relay and auxiliary contacts. RJ1 is a thermocouple, providing protection. If the fan motor shorts or experiences other faults, RJ1 disconnects, breaking the control circuit and tripping K1, causing first cooling fan 401 to stop. Y represents the operating indicator for inverter 1 and is active when inverter 1 is running. QK1 is the automatic / manual selector switch. When switch QK1 is in contact ③ and contact ④, the system enters automatic start / stop mode. When inverter 1 is running (contact Y closed) and switch QK1 is in automatic start / stop mode, first cooling fan 401 starts. Fan 1 stops when inverter 1 is stopped (contact Y open). When switch QK1 is switched to points ① and ⑥, it is in manual start / stop mode. Button B11 is the start button for first cooling fan 401, and button B12 is the stop button for first cooling fan 401. Pressing button B11 starts first cooling fan 401, and pressing button B12 stops first cooling fan 401. When switch QK1 is switched to points ② and ⑤, it is in the stop position, and first cooling fan 401 cannot be started automatically or manually.

[0042] Under normal circumstances, the switch QK1 is switched to "automatic", and contacts ③ and ④ are connected. When the inverter is put into operation, contact Y is connected, and there is no action of the thermocouple RJ1 (that is, the auxiliary contact of the thermocouple RJ1 is connected), the relay K1 is energized, and the first cooling fan 401 starts to run automatically.

[0043] The second cooling fan 402 is a backup fan used for starting the inverter 1 when the temperature is high or in other situations. The control circuit of the second cooling fan 402 is as follows: Figure 7As shown, the control circuit of the second cooling fan 402 incorporates the normally closed contact of the power contactor K1 of the first cooling fan 401. When the first cooling fan 401 trips and the power contactor K1 opens, the second cooling fan 402 automatically starts if it is in automatic start / stop mode. When the selector switch QK2 is switched to contact ① and contact ⑥, the control circuit enters manual start / stop mode. Button B21 is the start button for the second cooling fan 402, and button B22 is the stop button. Pressing button B21 starts the second cooling fan 402, and pressing button B22 stops it. When the selector switch QK2 is switched to contact ② and contact ⑤, the control circuit enters the stop position, preventing the second cooling fan 402 from being started either automatically or manually. K2 represents the power contactor for the second cooling fan 402, along with its corresponding relay and auxiliary contacts. RJ2 is a thermocouple, which provides protection by tripping the second cooling fan 402 in the event of a short circuit or other fault. QK2 is the automatic / manual switch, Y is the inverter operation indicator, T is the time relay, and WJ is the thermostat auxiliary contact. When QK2 is switched to contacts ③ and ④ are connected, the system is in automatic start / stop mode. When inverter 1 is running (contact Y is closed) and the thermostat measures that the ambient temperature inside the inverter cabinet is as high as the set temperature t1, the thermostat auxiliary contact WJ closes. After the delay set by time relay T (to prevent temperature fluctuations and frequent fan starts and stops), contact T closes, and the second cooling fan 402 starts. When the ambient temperature inside the inverter cabinet drops back to the set temperature t2, the thermostat auxiliary contact WJ opens, time relay T loses power, and second cooling fan 402 stops. When inverter 1 stops (contact Y is open), second cooling fan 402 also stops. (Note: The setting value t1>t2; the specific value can be set differently according to the production site environment and local climate.)

[0044] Under normal circumstances, the switch QK2 is switched to "auto", and contacts ③ and ④ are connected. After the inverter 1 is put into operation, contact Y is connected, and there is no action of the thermocouple RJ2 (that is, the auxiliary contact of the thermocouple RJ2 is connected). Since the normally open contact T of the time relay T is disconnected, the contactor K2 is disconnected, and the second cooling fan 402 stops running. When the ambient temperature in the inverter cabinet is as high as the thermostat set temperature t1, the contact WJ is closed, the time relay T is energized, and after a delay, the contact T is closed, the relay K2 is energized, the contactor K2 is energized, and the second cooling fan 402 starts. When the ambient temperature in the inverter cabinet drops to the thermostat set value t2, the contact WJ is disconnected, the time relay T loses power, its normally open contact T is disconnected, the relay K2 loses power, the contactor K2 is opened, and the second cooling fan 402 stops running.

[0045] When the inverter 1 needs to keep the fan in the stopped state due to maintenance or other reasons, switch QK1 and switch QK2 are switched to "stop", contact ② and contact ⑤ are connected, and the manual and automatic control circuits are both in the disconnected position.

[0046] To manually start or stop the fan, switch QK1 to "Manual," connect contacts ① and ⑥, press button B11, energize K1, close contactor K1, and close auxiliary contact K1 to keep K1 energized, starting the first cooling fan 401. Press button B12, de-energize K1, open contactor K1, and deactivate the first cooling fan 401. Switch switch QK2 to "Manual," connect contacts ① and ⑥, press button B21, energize K2, close contactor K2, and close auxiliary contact K21 to keep relay K2 energized, starting the second cooling fan 402. Press button B22, de-energize K2, open contactor K2, and stop the second cooling fan 402.

[0047] The present invention solves the problem that the inverter cabinet door needs to be opened for a long time and blown directly by an axial flow fan. Even if the cabinet door is closed during operation, the temperature inside the inverter cabinet can be kept normal, effectively preventing the inverter from getting damp or small animals from entering.

[0048] Example 2

[0049] This embodiment provides a frequency converter cooling method, which cools the frequency converter by using the frequency converter cooling system in the embodiment, including the following steps:

[0050] The switches of the control circuits of the first cooling fan 401 and the second cooling fan 402 are switched to contacts ③ and ④, so that the automatic start and stop circuits of the first cooling fan 401 and the second cooling fan 402 are connected. When the inverter 1 starts running, the auxiliary contact of the thermocouple RJ1 is turned on, the relay K1 is energized, and the first cooling fan 401 automatically starts to cool the inverter cabinet. At the same time, the auxiliary contact of the thermocouple RJ2 is turned on, the contactor K2 is disconnected, and the second cooling fan 402 stops running.

[0051] When the ambient temperature inside the inverter cabinet reaches the set temperature t1 of the thermostat, the thermostat auxiliary contact WJ is closed, the time relay T is energized, and after a delay, the contact T is closed, the contactor K2 is energized, and the second cooling fan 402 is started;

[0052] When the ambient temperature inside the inverter cabinet drops to the thermostat setting value t2, the thermostat auxiliary contact WJ is disconnected, the time relay T loses power, its normally open contact T is disconnected, the contactor K2 is opened, and the second cooling fan 402 stops running, completing the cooling of the inverter 1.

[0053] The rest is the same as Example 1.

[0054] The above describes in detail the preferred embodiments of the present invention. It should be understood that those skilled in the art can make numerous modifications and variations based on the concepts of the present invention without inventive effort. Therefore, any technical solutions that can be derived by those skilled in the art through logical analysis, reasoning, or limited experimentation based on the concepts of the present invention and the prior art should be within the scope of protection defined by the claims.

Claims

1. A frequency converter cooling system, comprising a frequency converter (1) and a frequency converter cabinet, characterized in that: The frequency converter cabinet comprises a cabinet body (2) and a cabinet door (3); the frequency converter (1) is arranged on the rear side of the cabinet body (2); a cooling fan (4) and a controller (7) are also arranged on the rear side of the cabinet body (2); the controller (7) is connected to the cooling fan (4); the controller (7) is used to control the start and stop of the cooling fan (4) according to the ambient temperature in the frequency converter cabinet; an air inlet (5) is arranged on the cabinet door (3); and a detachable filter (6) is arranged on the cooling fan (4) and the air inlet (5).

2. The inverter cooling system according to claim 1, characterized in that: The cabinet door (3) is connected to the cabinet body (2) via a hinge.

3. The inverter cooling system according to claim 1, characterized in that: The size of the cooling fan (4) is matched with the size of the air inlet (5).

4. The inverter cooling system according to claim 3, characterized in that: The cooling fan (4) comprises a first cooling fan (401) and a second cooling fan (402), and the first cooling fan (401) and the second cooling fan (402) are symmetrically arranged on the rear side of the cabinet body (2) on the other side of the inverter (1).

5. The inverter cooling system according to claim 4, characterized in that: The air inlet (5) comprises a first air inlet (501) and a second air inlet (502), and the first air inlet (501) and the second air inlet (502) are symmetrically arranged on the cabinet door (3) in an upper and lower direction.

6. The inverter cooling system according to claim 5, characterized in that: When the cabinet door (3) is closed, the axis of the first cooling fan (401) coincides with the axis of the first air inlet (501), thereby forming a first cooling air duct, and the axis of the second cooling fan (402) coincides with the axis of the second air inlet (502), thereby forming a second cooling air duct.

7. The inverter cooling system according to claim 6, characterized in that: The controller (7) includes a first cooling fan (401) control circuit and a second cooling fan (402) control circuit, the control circuit of the first cooling fan (401) includes an automatic start-stop control circuit and a manual start-stop control circuit, the automatic start-stop control circuit and the manual start-stop control circuit are connected through a switching switch, and the automatic start-stop control circuit of the first cooling fan (401) is provided with a frequency converter operation indication Y, a thermocouple RJ1 and a relay K1; the control circuit of the second cooling fan (402) includes an automatic start-stop control circuit, a manual start-stop control circuit, a normally closed contact circuit of the power contactor K1 of the first cooling fan 401 and a thermostat auxiliary contact WJ circuit, the automatic start-stop control circuit and the manual start-stop control circuit are connected through a switching switch, and the automatic start-stop control circuit of the second cooling fan (402) is provided with a time relay T, a contactor K2 and a thermocouple RJ2.

8. The inverter cooling system according to claim 7, characterized in that: The switch is provided with 6 contacts. When contact ① and contact ⑥ are connected, it is the manual start-stop position; when contact ② and contact ⑤ are connected, it is the stop position; when contact ③ and contact ④ are connected, it is the automatic start-stop position.

9. The inverter cooling system according to claim 1, characterized in that: The cooling fan (4) and the air inlet (5) are provided with a slide groove, the width of which matches the thickness of the detachable filter (6), and the detachable filter (6) can be disassembled and installed through the slide groove.

10. A frequency converter cooling method, characterized in that: Cooling the inverter by using the inverter cooling system according to any one of claims 1 to 9 comprises the following steps: The switching switch of the control circuit of the first cooling fan (401) and the second cooling fan (402) is switched to the connection of contact ③ and contact ④, so that the automatic start-stop circuit of the first cooling fan (401) and the second cooling fan (402) is connected. When the frequency converter 1 starts to run, the auxiliary contact of the thermocouple RJ1 is turned on, the relay K1 is energized, and the first cooling fan (401) automatically starts to cool the frequency converter cabinet. At the same time, the auxiliary contact of the thermocouple RJ2 is turned on, the contactor K2 is disconnected, and the second cooling fan (402) stops running. When the ambient temperature in the inverter cabinet reaches the set temperature t1 of the thermostat, the thermostat auxiliary contact WJ is closed, the time relay T is energized, the contact T is closed after a delay, the contact K2 is energized, and the second cooling fan (402) is started; When the ambient temperature in the inverter cabinet drops to the thermostat setting value t2, the thermostat auxiliary contact WJ is disconnected, the time relay T loses power, its normally open contact T is disconnected, the contactor K2 is opened, and the second cooling fan (402) stops running, completing the cooling of the inverter 1.

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