High-voltage inverter control system

Abstract

The present invention provides an energy-saving system for cooling fans in high-voltage inverters that features simple implementation, low energy consumption, high heat dissipation power utilization, low noise, and intelligent adjustment. The high-voltage inverter control system comprises: a high-voltage inverter with a control unit; one or more cooling fans mounted on the high-voltage inverter; and one or more fan inverters connected between an industrial power supply and the cooling fans. The control unit controls the output frequency of the fan inverters.

Description

Technical Field

[0001] The present invention relates to the field of high-voltage frequency converters, and in particular to a high-voltage frequency converter control system that realizes energy saving of a heat dissipation fan for the high-voltage frequency converter. Background Art

[0002] High-voltage inverters usually generate a lot of heat during normal operation due to their high power. To ensure the normal operation of the equipment, a large amount of heat must be dissipated through the cooling system.

[0003] To address this issue, existing high-voltage inverters typically install a cooling fan on top of the cabinet housing the inverter. This uses forced air cooling to circulate air within the cabinet, thereby removing heat generated by components such as power modules within the cabinet and removing it from the cabinet to achieve the required operating temperature for the high-voltage inverter. Existing cooling fans for high-voltage inverters typically utilize direct power frequency start-up and direct power frequency operation, meaning all cooling fans are connected to a power frequency power supply. However, this has the following drawbacks:

[0004] 1. Regardless of the actual operating conditions of the load, the cooling fan runs at full speed, which consumes high energy and does not save energy. The user's electricity cost will also increase;

[0005] 2. Since the cooling fan of the high-voltage inverter will generate very loud noise when running at full speed, it will cause great harm to the workers who are engaged in long-term equipment commissioning and maintenance. The workers must wear anti-noise sheaths for protection, which is not conducive to their occupational health;

[0006] 3. Due to the large starting current, it is easy to cause instantaneous impact on the power grid;

[0007] 4. Since the cooling fan that discharges the heat in the cabinet has a large air volume when running at full speed, the filter on the cabinet that filters the air entering the cabinet is more likely to become dirty. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide an energy-saving system for a heat dissipation fan of a high-voltage inverter, which has a simple implementation method, low energy consumption, high heat dissipation power utilization, low noise and can be intelligently adjusted, in response to the technical problems existing in the above-mentioned prior art.

[0009] The high-voltage inverter control system of the present invention comprises: a high-voltage inverter having a control unit; one or more heat dissipation fans arranged on the high-voltage inverter; and one or more fan inverters connected between an industrial frequency power supply and the heat dissipation fans, wherein the control unit controls the output frequency of the fan inverters.

[0010] According to the present invention, an energy-saving system for a heat dissipation fan of a high-voltage inverter can be provided, which has a simple implementation method, low energy consumption, high heat dissipation power utilization, low noise and intelligent adjustment. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a diagram schematically showing the arrangement relationship between the high-voltage inverter and the heat dissipation fan of the present invention.

[0012] Figure 2 Schematic diagram of a high-voltage inverter control system according to a first embodiment.

[0013] Figure 3 Schematic diagram of a high-voltage inverter control system according to a second embodiment.

[0014] Figure 4 Schematic diagram of a high-voltage inverter control system according to a third embodiment.

[0015] Figure 5 Schematic diagram of a high-voltage inverter control system according to a fourth embodiment.

[0016] Figure 6 This is a diagram showing an example of an intelligent module for realizing a control unit of a high-voltage inverter. DETAILED DESCRIPTION

[0017] (Implementation Method 1)

[0018] like Figure 1 、 2 As shown, the high-voltage inverter control system of this embodiment has: a high-voltage inverter 1, as an example, can be an AC speed-regulating electric drive system with an AC voltage of more than 1000V but not more than 35kV, the high-voltage inverter 1 has a control unit, which can be, for example, Figure 6 The intelligent module shown is realized; multiple heat dissipation fans 2 are provided on the high-voltage inverter 1 (as an example, on the top of the cabinet of the high-voltage inverter 1) for dissipating heat to the high-voltage inverter 1; and more than one fan inverter 3 (in Figure 1 The inverter 3 is connected between the power supply and the cooling fan 2. The control unit of the high-voltage inverter 1 controls the output frequency of the fan inverter 3. Here, in order to independently adjust the speed of each cooling fan 2 by using each fan inverter 3, it is preferred to Figure 2 As shown, the frequency converter 3 for the fan is set to the same number as the cooling fan 2, that is, one frequency converter 3 for the fan drives one cooling fan 2. However, from the perspective of cost saving, the number of frequency converters 3 for the fan can also be set to be less than the number of cooling fans 2. For example, one frequency converter 3 for the fan can drive multiple cooling fans 2.

[0019] For the high-voltage inverter 1, a given temperature can be preset. The given temperature can be set at the factory or can be variably set through software, HMI screen or adding a temperature setting device according to the environment in which the high-voltage inverter is located.

[0020] The number of cooling fans 2 can be set according to the given temperature of the high-voltage inverter 1. In this embodiment, the number is set to the minimum number, i.e., the required number N, that can cool the high-voltage inverter 1 to a given temperature when all cooling fans 2 are running at full speed.

[0021] More specifically, a temperature detection unit is provided within the cabinet or a power unit of the high-voltage inverter 1. The control unit adjusts the speed of the cooling fan 2 in real time based on the cabinet temperature, the temperature of a power unit, or the average temperature of the power units detected by the temperature detection unit. For example, when the detected temperature rises, the control unit calculates and drives the fan inverter 3 to change its output frequency, thereby increasing the speed of the cooling fan 2. When the detected temperature decreases, the control unit calculates and drives the fan inverter 3 to change its output frequency, thereby decreasing the speed of the cooling fan 2. In addition, when the detected temperature exceeds a predetermined temperature, the control unit automatically disconnects (trips) the high-voltage inverter 1 due to overheat protection, thereby achieving energy saving and reducing noise. Alternatively, a current detection unit can be provided in place of the temperature detection unit. For example, when the current detection unit detects excessive current flowing through the cabinet of the high-voltage inverter, it provides feedback to the control unit, which then changes the output frequency of the fan inverter 3, thereby increasing the speed of the cooling fan 2.

[0022] In addition, since the temperature of the power unit of the high-voltage inverter 1 or the temperature inside the cabinet also indirectly reflects the load condition of the high-voltage inverter 1, the speed of the cooling fan 2 can also be adjusted according to the load condition. For example, when the load towed by the high-voltage inverter 1 is a water pump, when the power of the water pump is relatively low, it means that the current of the high-voltage inverter 1 is relatively low during operation and the temperature inside the cabinet is relatively low. Therefore, the above-mentioned control unit of the high-voltage inverter 1 controls the fan inverter 3 according to the low power of the water pump, so as to reduce the speed of the cooling fan 2, which can also achieve energy saving. In this way, the air volume brought by the cooling fan can be adjusted according to the actual situation, the service life of the filter can be extended, and the design of the system can be made more reasonable.

[0023] Alternatively, a wind pressure detection device may be installed within the cabinet of the high-voltage inverter 1, and an intelligent adaptive model may be provided within the control unit. This model may be used to adaptively match the pressure values ​​of the high-voltage inverter 1 at various speeds when equipped with a filter of a specific cleanliness level. Based on this pressure value, an appropriate wind pressure alarm value at each speed may be set. This wind pressure alarm value may also be set at the factory or through software, an HMI screen, or the like. For example, the wind pressure values ​​that the high-voltage inverter 1 should theoretically reach at various speeds when the filter is 100% clean may be pre-set, and the wind pressure alarm values ​​at each speed may be set based on these wind pressure values. Then, during actual operation, if the wind pressure value at a particular speed actually detected by the wind pressure detection device exceeds the pre-set wind pressure alarm value for that speed, the control unit may cause the alarm unit of the high-voltage inverter control system to sound an alarm. Upon receiving the alarm signal, operators and maintenance personnel will be informed that the filter needs to be replaced, thereby achieving an intelligent filter replacement reminder function.

[0024] Alternatively, the fan inverter 3 or the heat dissipation fan 2 itself also has a controller and an alarm unit, and when any fan inverter 3 or heat dissipation fan 2 fails, the corresponding controller performs control so that the alarm unit automatically alarms. In addition, it can also be further configured so that when any fan inverter 3 or heat dissipation fan 2 fails, the corresponding controller performs control so that the failed fan inverter 3 or heat dissipation fan 2 automatically disconnects (trips). More preferably, an automatic damper closing device is also provided for the heat dissipation fan 2, whereby when the heat dissipation fan 2 fails, the controller of the failed heat dissipation fan 2 controls the corresponding automatic damper closing device so that it closes the damper of the corresponding heat dissipation fan 2, thereby preventing the fan from reversing (the so-called "backdraft").

[0025] In addition, it can also be arranged that when any fan inverter 3 or cooling fan 2 fails, its own controller immediately sends a signal to the control unit of the high-voltage inverter 1, and the control unit controls the high-voltage inverter 1 to automatically disconnect (trip). In this case, it is also possible not to set the automatic damper closing device for the cooling fan.

[0026] (Implementation Method 2)

[0027] The main difference from the first embodiment is the number of cooling fans 2. In the first embodiment, the number of cooling fans 2 is designed to be the minimum number actually required, that is, the required number N, according to the heat output. However, in the present embodiment, Figure 3As shown, M spare cooling fans 2 are further redundantly configured, that is, the number of cooling fans 2 becomes N+M, where M ≤ N. Furthermore, M spare fan inverters 3 can also be redundantly configured to independently drive each of the N+M cooling fans 2.

[0028] In this case, in actual application, the control unit of the high-voltage inverter 1 can be controlled to operate N cooling fans 2 and disable M spare cooling fans 2. When a faulty cooling fan 2 among the N cooling fans 2 is present, one or more cooling fans 2 among the M cooling fans 2 is appropriately activated. As in the first embodiment, the faulty cooling fan 2 automatically closes its damper using an automatic damper closing device to prevent backdraft. Alternatively, while the N cooling fans 2 are being activated, the control unit of the high-voltage inverter 1 can also activate one or more cooling fans 2 among the M cooling fans 2. In this case, the operating cooling fans 2 do not all need to run at full speed, but rather adjust their speeds based on the real-time temperature within the cabinet to achieve the desired airflow. Similarly, when a faulty cooling fan 2 among the operating cooling fans 2 is present, the damper of the faulty cooling fan 2 is automatically closed using the automatic damper closing device, and the remaining non-operating cooling fans 2 among the M cooling fans 2 are activated.

[0029] In this embodiment, it can also be configured that if the number of failed fan inverters 3 or heat dissipating fans 2 exceeds the specified number, the control unit of the high-voltage inverter 1 controls the high-voltage inverter 1 to automatically disconnect (trip). In other words, if the number of failed fan inverters 3 or heat dissipating fans 2 is less than the specified number, the high-voltage inverter 1 will not automatically disconnect (trip). In this case, it is preferred that when a failure occurs, the controller of the fan inverter 3 or heat dissipating fan 2 sends a signal to the control unit of the high-voltage inverter 1 indicating that the failure has occurred, thereby enabling the control unit of the high-voltage inverter 1 to count the number of failed fan inverters 3 or heat dissipating fans 2. In addition, it is also possible that when the number of failed fan inverters 3 or heat dissipating fans 2 exceeds the specified number, the high-voltage inverter 1 does not disconnect (trip) immediately, but, as in the first embodiment, when the internal temperature exceeds a given temperature, the high-voltage inverter 1 automatically disconnects (trips) due to overheating protection.

[0030] According to this embodiment, by adding redundant cooling fans 2 (and fan inverters 3), reliability can be improved and the service life of cooling fans 2 (and fan inverters 3) can be extended. Moreover, if only 1 to M fan inverters 3 or cooling fans 2 fail, the normal operation of high-voltage inverter 1 will not be affected in theory.

[0031] Other than that, since it is the same as the first embodiment, it will not be repeated.

[0032] (Implementation Method 3)

[0033] The main difference between this embodiment and the first embodiment is that a contactor is further provided as a switching device.

[0034] In detail, Figure 4 As shown, assuming that N fan inverters 3 each drive N cooling fans 2, first to third contactors are provided for each fan inverter 3. The first contactor is connected between the power supply and the fan inverter 3, the second contactor is connected between the fan inverter 3 and the cooling fan 2, and the third contactor is connected between the power supply and the cooling fan 2. During operation, the first and second contactors are connected, and the third contactor is disconnected. However, if, for example, a fan inverter 3 fails, the controller of the fan inverter 3 sends a fault signal to the control unit of the high-voltage inverter 1. Upon receiving the fault signal, the control unit disconnects the first and second contactors before and after the fan inverter 3 and connects the third contactor. As a result, while the fan inverter 3 is disconnected, the cooling fan 2 can continue to operate. Since the fan inverter 3 is no longer energized, it can be safely removed from the system for maintenance.

[0035] Here, from the perspective of reducing the impact on the power grid, it is more preferred that when a frequency converter 3 for a certain wind turbine fails, its corresponding second contactor is disconnected first, and then the third contactor is connected after a delay of Y (Y value is adjustable on site) seconds, and then the first contactor is disconnected after a delay of Z (Z value is adjustable on site).

[0036] In addition, when a certain cooling fan 2 fails, or a certain fan inverter 3 and its corresponding cooling fan 2 both fail, the corresponding controller may send a signal indicating the failure to the control unit of the high-voltage inverter 1. After receiving the fault signal, the control unit disconnects at least one of the first and second contactors and does not connect the third contactor.

[0037] In the case where one fan inverter 3 drives multiple cooling fans 2, the same situation as above can also be applied. For example, when a certain fan inverter 3 fails, the control unit of the high-voltage inverter 1 disconnects the first and second contactors of the fan inverter 3 and connects the third contactor.

[0038] Other than that, since it is the same as the first embodiment, it will not be repeated.

[0039] (Implementation Method 4)

[0040] The fourth embodiment combines the redundancy of the second embodiment with the third embodiment. Figure 5 Since it has been explained above, it will not be repeated here.

[0041] Although several embodiments of the present invention have been described above, these embodiments are provided as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other ways and can be combined, omitted, replaced, or modified in various ways without departing from the scope of the invention. These embodiments and their variations are included in the scope and spirit of the invention and are included in the invention described in the claims and their equivalents.

Claims

1. A high voltage inverter control system, characterized in that: have: A high-voltage frequency converter having a control unit; One or more heat dissipation fans, provided on the high-voltage inverter; and One or more fan frequency converters are connected between the industrial frequency power supply and the cooling fan. The control unit controls the output frequency of the fan inverter. A wind pressure detection device is provided in the cabinet of the high-voltage inverter, and an intelligent adaptive model is provided in the control unit. The intelligent adaptive model is used to adaptively match the wind pressure value of the high-voltage inverter equipped with a filter with a specific cleanliness level at various fan speeds. The wind pressure alarm value at various fan speeds is set according to the wind pressure value. The high-voltage inverter control system also has an alarm unit. When the wind pressure value detected by the wind pressure detection device exceeds the pre-set wind pressure alarm value at the current speed of the fan, the control unit controls the alarm unit to sound an alarm.

2. The high-voltage inverter control system according to claim 1, characterized in that: A temperature detection unit is provided in the high-voltage inverter, and the control unit controls the fan inverter according to the temperature in the high-voltage inverter detected by the temperature detection unit.

3. The high-voltage inverter control system according to claim 2, characterized in that: For the high voltage inverter, a given temperature is preset. When the temperature inside the high-voltage inverter detected by the temperature detection unit exceeds the predetermined temperature, the control unit automatically turns off the high-voltage inverter.

4. The high-voltage inverter control system according to claim 3, characterized in that: For the high-voltage converter, a given temperature is variably set.

5. The high-voltage inverter control system according to claim 1, characterized in that: A current detection unit is provided in the high-voltage inverter, and the control unit controls the inverter for the fan according to the current in the high-voltage inverter detected by the current detection unit.

6. The high-voltage inverter control system according to claim 1, characterized in that: The control unit controls the inverter for the fan according to the load driven by the high-voltage inverter.

7. The high-voltage inverter control system according to claim 1, characterized in that: The frequency converters for the fans are set to be the same in number as the heat dissipation fans, and one frequency converter for the fans drives one heat dissipation fan.

8. The high-voltage inverter control system according to claim 1, characterized in that: The number of the frequency converters for the fans is less than the number of the heat dissipation fans.

9. The high-voltage inverter control system according to claim 1, characterized in that: The heat dissipation fan is also provided with an automatic damper closing device. The heat dissipation fan itself has a controller, When the heat dissipation fan fails, the controller of the heat dissipation fan that fails controls the damper automatic closing device of the heat dissipation fan that fails to close the damper of the heat dissipation fan that fails.

10. The high-voltage inverter control system according to claim 1, characterized in that: A given temperature is preset for the high-voltage inverter, and the number of the heat dissipation fans is set to be the minimum number that can cool the high-voltage inverter to the given temperature when all the heat dissipation fans are running at full speed.

11. The high-voltage inverter control system according to claim 1, characterized in that: A given temperature is preset for the high-voltage inverter, and the number of the heat dissipation fans is set to be greater than the minimum number that can cool the high-voltage inverter to the given temperature when all the heat dissipation fans are running at full speed.

12. The high-voltage inverter control system according to claim 11, characterized in that: The heat dissipation fan is also provided with an automatic damper closing device. The heat dissipation fan itself has a controller, The control unit controls to make part of the cooling fans work. When there is a faulty cooling fan among the working cooling fans, the control unit controls to make one or more of the other cooling fans that are not working work, and the controller of the faulty cooling fan controls the damper automatic closing device of the faulty cooling fan to close the damper of the faulty cooling fan.

13. The high-voltage inverter control system according to claim 11, characterized in that: The fan frequency converter and / or the heat dissipation fan itself has a controller, When the fan inverter and / or the cooling fan fails, the controller thereof sends a signal indicating the failure to the control unit of the high-voltage inverter. The control unit counts the number of the fan inverters and / or the cooling fans that have failed. When the number of the fan inverters and / or the cooling fans that have failed exceeds a specified number, the control unit controls the high-voltage inverter to automatically disconnect.

14. The high-voltage inverter control system according to claim 1, characterized in that: The frequency converter for the fan and / or the heat dissipation fan itself has a controller and an alarm unit. When the frequency converter for the fan and / or the heat dissipation fan fails, the controller of the failed frequency converter for the fan and / or the heat dissipation fan controls the alarm unit of the failed frequency converter for the fan and / or the heat dissipation fan to sound an alarm.

15. The high-voltage inverter control system according to claim 1, characterized in that: The fan frequency converter and / or the heat dissipation fan itself has a controller, When the fan inverter and / or the heat dissipation fan fails, the controller of the failed fan inverter and / or the heat dissipation fan controls the failed fan inverter and / or the heat dissipation fan to disconnect the failed fan inverter and / or the heat dissipation fan.

16. The high-voltage inverter control system according to claim 1, characterized in that: The fan frequency converter and / or the heat dissipation fan itself has a controller, When the fan inverter and / or the heat dissipation fan fails, the controller of the failed fan inverter and / or the heat dissipation fan sends a signal to the control unit of the high-voltage inverter, and the control unit controls the high-voltage inverter to disconnect.

17. The high-voltage inverter control system according to claim 1, characterized in that: The fan frequency converter has a controller. The fan inverter is provided with a first contactor, a second contactor, and a third contactor as a switching device, wherein the first contactor is connected between the industrial frequency power supply and the fan inverter, the second contactor is connected between the fan inverter and the heat dissipation fan, and the third contactor is connected between the industrial frequency power supply and the heat dissipation fan. When the frequency converter for the wind turbine is not faulty, the first contactor and the second contactor are connected, and the third contactor is disconnected. When a fault occurs in the inverter for the fan, the controller of the faulty inverter for the fan sends a signal indicating the fault to the control unit of the high-voltage inverter, and the control unit controls so that the first contactor and the second contactor corresponding to the faulty inverter for the fan are disconnected and the corresponding third contactor is connected.

18. The high-voltage inverter control system according to claim 17, characterized in that: When the inverter for the fan fails, the control unit controls to first open the second contactor corresponding to the inverter for the fan, then close the corresponding third contactor, and finally open the corresponding first contactor.

19. The high-voltage inverter control system according to claim 17, characterized in that: The heat dissipation fan has a controller, When the cooling fan fails, the controller of the failed cooling fan sends a signal indicating the failure to the control unit of the high-voltage inverter, and the control unit controls so that at least one of the first contactor and the second contactor corresponding to the failed cooling fan is disconnected and the third contactor is not connected.

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