Power supply device for supplying power to control system of frequency converter and frequency converter

Abstract

The utility model provides a power supply device for supplying power to a control system of a frequency converter and the frequency converter, the frequency converter comprises a phase-shifting transformer, the phase-shifting transformer comprises a primary winding arranged at a primary side, and the primary winding receives a first voltage; the phase-shifting transformer comprises a first-path three-phase alternating-current power supply circuit and a second-path three-phase alternating-current power supply circuit, the first-path three-phase alternating-current power supply circuit comprises a first-path three-phase alternating-current power supply circuit, a second-path three-phase alternating-current power supply circuit, a second-path three-phase alternating-current power supply circuit and a third-path three-phase alternating-current power supply circuit, the first three-phase alternating current power supply circuit comprises an auxiliary winding of a phase-shifting transformer, and the first three-phase alternating current power supply circuit is provided with a first phase line, a second phase line and a third phase line. The power supply device can supply power to the control system through the auxiliary winding added to the secondary side of the phase-shifting transformer, and the requirement of customers for providing auxiliary power can be reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of frequency converters, and more specifically to a power supply of a control system of the frequency converter and a frequency converter. Background Art

[0002] As a motor energy-saving and speed-regulating device, frequency converters have been widely used in metallurgy, electricity, water supply, petroleum, chemical industry, coal and other fields. Users have put forward higher and higher requirements for their reliability. In addition to the reliability of the device itself, its internal control power supply is directly related to whether the device can operate reliably, safely and stably. At present, for equipment such as frequency converters, customers need to provide 380V or 220V auxiliary AC power for these equipment on site. These auxiliary AC power supplies have relatively high requirements and require large capacity. Utility Model Content

[0003] 1. Technical issues

[0004] In view of the above-mentioned shortcomings of the prior art, the utility model provides a power supply device for supplying power to the control system of the frequency converter, which can effectively overcome the technical problems of the prior art that the auxiliary AC power supply provided by the customer on site has high requirements and large capacity.

[0005] (II) Technical solution

[0006] In order to achieve the above objectives, the present invention is implemented through the following technical solutions:

[0007] According to one aspect of an embodiment of the present application, a power supply device for supplying power to a control system of a frequency converter is provided, the frequency converter includes a phase-shifting transformer, the phase-shifting transformer includes a primary winding arranged on the primary side, the primary winding receives a first voltage; and a secondary winding arranged on the secondary side, the secondary winding outputs a second voltage lower than the first voltage, the phase-shifting transformer also includes an auxiliary winding arranged on the secondary side, the auxiliary winding is separated from the secondary winding, and the auxiliary winding outputs a third voltage lower than the first voltage, the power supply device includes a first three-phase AC power supply circuit, the first three-phase AC power supply circuit includes an auxiliary winding of the phase-shifting transformer, the first three-phase AC power supply circuit has a first phase line, a second phase line and a third phase line, and the first three-phase AC power supply circuit supplies power to the control system of the frequency converter through the third voltage output by the auxiliary winding.

[0008] In this way, by adding an auxiliary winding on the secondary side of the phase-shifting transformer, the secondary side of the phase-shifting transformer can be used to power the control system of the inverter, thereby reducing the need for the customer to provide auxiliary AC power on site, and the power supply voltage of the auxiliary winding on the secondary side of the phase-shifting transformer can be adjusted according to the wind turbine voltage. That is, the auxiliary winding on the secondary side of the phase-shifting transformer can not only provide 380V / 400V voltage, but also other voltage values ​​such as 415V. The advantage of this is that when the wind turbine voltage is 415V, but the customer-side power supply is only 380V or 400V, there is no need for the customer to add a separate step-up transformer to change the voltage, which reduces the customer's investment and space usage.

[0009] According to an exemplary embodiment of the present application, the power supply device also includes a pre-charging circuit, which is connected to the first phase line, the second phase line and the third phase line of the first three-phase AC power supply circuit to supply power to the auxiliary winding to pre-charge the inverter, and the pre-charging circuit and the first three-phase AC power supply circuit are constructed to interlock with each other to allow the pre-charging circuit and one of the first three-phase AC power supply circuit to operate.

[0010] In this way, the auxiliary winding is powered by the pre-charging circuit to pre-charge the inverter, so that the high voltage impact on the capacitor, rectifier and other devices inside the power unit connected to the secondary winding is prevented in the process of providing high voltage to the phase-shifting transformer, thereby extending the service life of the inverter and improving the reliability of the inverter. Moreover, the auxiliary winding of the phase-shifting transformer can be used as both a power supply winding and a pre-charging winding, which simplifies the entire auxiliary power supply circuit and reduces the cost of the power supply circuit and the pre-charging circuit.

[0011] According to an exemplary embodiment of the present application, the power supply device also includes a second three-phase AC power supply circuit, the second three-phase AC power supply circuit includes an external power supply, the second three-phase AC power supply circuit has a first phase line, a second phase line and a third phase line, and the second three-phase AC power supply circuit supplies power to the control system of the inverter through the power supply voltage provided by the external power supply, wherein the first three-phase AC power supply circuit and the second three-phase AC power supply circuit are constructed to interlock with each other to supply power to the control system through one of the first three-phase AC power supply circuit and the second three-phase AC power supply circuit.

[0012] In this way, the customer provides power on site as a redundant power supply. Since the first three-phase AC power supply circuit and the second three-phase AC power supply circuit are interlocked with each other, only one of them supplies power to the control system. Therefore, when one power supply circuit loses power, it can switch to the other power supply circuit, thereby avoiding the risk of power loss of the entire control power supply due to damage to a single power supply, thereby improving the power supply reliability and operating stability of the inverter.

[0013] According to an exemplary embodiment of the present application, the power supply device also includes a switching contactor, which is used to switch the power supply from the first three-phase AC power supply circuit to the control system to the second three-phase AC power supply circuit, or to switch the power supply from the second three-phase AC power supply circuit to the control system to the first three-phase AC power supply circuit.

[0014] In this way, it is possible to switch the power supply from the first three-phase AC power supply circuit to the second three-phase AC power supply circuit, or to switch the power supply from the second three-phase AC power supply circuit to the first three-phase AC power supply circuit, using only a switching contactor. The circuit structure is simple and the space occupied is small.

[0015] According to an exemplary embodiment of the present application, the power supply device also includes an output circuit, the output circuit includes a first output terminal, a second output terminal and a third output terminal, the first phase line of the first three-phase AC power supply circuit and the first phase line of the second three-phase AC power supply circuit are connected to the first output terminal, the second phase line of the first three-phase AC power supply circuit and the second phase line of the second three-phase AC power supply circuit are connected to the second output terminal, and the third phase line of the first three-phase AC power supply circuit and the third phase line of the second three-phase AC power supply circuit are connected to the third output terminal.

[0016] According to an exemplary embodiment of the present application, the power supply device further includes an electromagnetic compatibility filter circuit connected to the first output terminal, the second output terminal, and the third output terminal of the output circuit to filter out noise signals.

[0017] In this way, the first three-phase AC power supply circuit and the second three-phase AC power supply circuit are combined into one in the output circuit, that is, the two inputs are combined into one output. At the same time, only one EMC filter needs to be added, instead of adding two EMC filters to the two inputs. This saves space and cost. The EMC filter is an optional circuit, and the entire circuit can be implemented without the EMC filter.

[0018] According to an exemplary embodiment of the present application, the control system is connected to the electromagnetic compatibility filter circuit through a terminal bus bar to draw a three-phase voltage through the terminal bus bar.

[0019] In this way, the number of terminals can be expanded through the terminal bus according to the required number of wind turbines, thereby expanding the number of connected wind turbine control circuits and the number of corresponding wind turbines.

[0020] According to an exemplary embodiment of the present application, the power supply device further includes a third power supply circuit, which draws two-phase voltages from the three-phase voltage from the terminal bus to provide the control system with a two-phase voltage having a voltage lower than the three-phase voltage.

[0021] In this way, the third power supply circuit can provide the system with, for example, 220 V power. The third power supply circuit has two inputs, that is, two inputs and one output, which can ensure the input of multiple power supplies and provide a more reliable power input for the control system.

[0022] According to an exemplary embodiment of the present application, the power supply device also includes a voltage collection circuit, which is connected to the first phase line, the second phase line and the third phase line of the first three-phase AC power supply circuit to collect the third voltage output by the auxiliary winding of the phase-shifting transformer.

[0023] In this way, the auxiliary winding of the transformer can be fully utilized, that is, by collecting the third voltage output by the auxiliary winding of the phase-shifting transformer, the primary voltage of the transformer can be monitored, and high and low voltage isolation can be achieved. This can reduce the problems of insulation and electrical clearance caused by direct high-voltage voltage collection. In addition, the cost of the entire voltage acquisition circuit and the volume occupied by components can be reduced.

[0024] According to an exemplary embodiment of the present application, a first three-phase AC power supply circuit includes a first contactor, a pre-charging circuit includes a second contactor, the pre-charging circuit is connected to a first phase line, a second phase line and a third phase line of the first three-phase AC power supply circuit through the second contactor, the second contactor is connected to a status contact of the first contactor, the first contactor is connected to a status contact of the second contactor, the pre-charging circuit and the first three-phase AC power supply circuit are interlocked with each other through the first contactor and the second contactor, wherein the status contact is a normally open contact or a normally closed contact.

[0025] According to an exemplary embodiment of the present application, the first three-phase AC power supply circuit also includes a first contactor, and the second three-phase AC power supply circuit also includes a third contactor. The first contactor is connected to the first phase line and the second phase line of the first three-phase AC power supply circuit and is connected to the status contact of the third contactor. The third contactor is connected to the first phase line and the second phase line of the second three-phase AC power supply circuit and is connected to the status contact of the first contactor. The first three-phase AC power supply circuit and the second three-phase AC power supply circuit are interlocked with each other through the first contactor and the third contactor, wherein the status contact is a normally open contact or a normally closed contact.

[0026] In this way, circuit interlocking can be achieved through the contactor, thereby simplifying the circuit structure and reducing the circuit cost.

[0027] According to an exemplary embodiment of the present application, when the first three-phase AC power supply circuit serves as the main power supply circuit and the second three-phase AC power supply circuit serves as the auxiliary power supply circuit, the switching contactor is connected to the first phase line and the second phase line of the first three-phase AC power supply circuit, and the third contactor is also connected to the status contact of the switching contactor. The switching contactor is used to switch the power supply from the second three-phase AC power supply circuit to the first three-phase AC power supply circuit.

[0028] According to an exemplary embodiment of the present application, when the second three-phase AC power supply circuit serves as the main power supply circuit and the first three-phase AC power supply circuit serves as the auxiliary power supply circuit, the switching contactor is connected to the first phase line and the second phase line of the second three-phase AC power supply circuit, and the first contactor is also connected to the status contact of the switching contactor. The switching contactor is used to switch the power supply from the first three-phase AC power supply circuit to the second three-phase AC power supply circuit.

[0029] In this way, the auxiliary winding of the phase-shifting transformer or the customer power supply can be determined as the main power supply circuit according to whether the switching contactor is set on the phase-shifting transformer side or the customer power supply side, thereby achieving circuit flexibility.

[0030] According to an exemplary embodiment of the present application, the first three-phase AC power supply circuit and the second three-phase AC power supply circuit provide a voltage of 380V or 400V.

[0031] According to an exemplary embodiment of the present application, the first three-phase AC power supply circuit can provide a voltage of 380V-500V.

[0032] According to an exemplary embodiment of the present application, the third power supply circuit provides a voltage of 220V to the control system.

[0033] In this way, different voltage inputs of the control system can be guaranteed, providing a more reliable power input for the control system.

[0034] According to another exemplary embodiment of the present application, a frequency converter is provided. The frequency converter includes a control system and the above-mentioned power supply device, and the power supply device is used to supply power to the control system.

[0035] (III) Technical Effect

[0036] In an embodiment of the present application, a power supply device for supplying power to a control system of a frequency converter is provided. The power supply device supplies power to the control system of the frequency converter by utilizing an auxiliary winding added on the secondary side of a phase-shifting transformer, thereby reducing the need for the customer to provide an auxiliary AC power supply on site, and the power supply voltage of the auxiliary winding on the secondary side of the phase-shifting transformer can be adjusted according to the fan voltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0038] Figure 1 4 is a circuit diagram of a power supply device for supplying power to a control system of a frequency converter according to an embodiment of the present application.

[0039] Description of Figure Numbers:

[0040] 1: A power supply device used to supply power to the control system of the inverter;

[0041] 10: Phase shifting transformer;

[0042] 20: The first three-phase AC power supply circuit;

[0043] 30: pre-charging circuit;

[0044] 40: Second three-phase AC power supply circuit;

[0045] 50: switching unit;

[0046] 60: output circuit;

[0047] 70: Electromagnetic compatibility filter circuit;

[0048] 80: Terminal busbar;

[0049] 90: third power supply circuit;

[0050] 100: Voltage acquisition circuit. DETAILED DESCRIPTION

[0051] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0052] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0053] As discussed in the previous background technology, the problem faced by powering the control system of the frequency converter is that for the frequency converter and other equipment, the customer site needs to provide 380V or 220V auxiliary AC power for these equipment. These auxiliary AC power supplies have relatively high requirements and require large capacity, making it difficult to stably supply power to the control system.

[0054] To this end, the concept of the utility model is to make full use of the characteristics of the secondary of the phase-shifting transformer of the frequency converter. In addition to the secondary winding of the phase-shifting transformer to supply power to the power unit, an auxiliary winding is also provided on the secondary side of the phase-shifting transformer. After the frequency converter is energized, the auxiliary winding of the phase-shifting transformer of the frequency converter is used to supply power to the control system, thereby reducing the pressure and loss of power supply on the customer side.

[0055] On the other hand, the auxiliary winding of the phase-shifting transformer of the inverter and the customer power supply can also realize the redundancy of the power supply to the control system, providing the stability and reliability of the system. Specifically, one power supply is the customer power supply on the customer side, which can be used as a startup power supply or a redundant power supply; the other power supply is the auxiliary winding of the phase-shifting transformer. The two power supplies are interlocked with each other. At the same time, when one power supply loses power, it switches to the other power supply. In addition, it is also possible to set any power supply as the main power supply circuit. Moreover, the auxiliary winding of the phase-shifting transformer can also be used as a pre-charging winding. Although the pre-charging winding and the power supply winding share a winding, there is a time difference between the two functional circuits. This feature can be fully utilized to perform logical control at different times, simplify the entire power supply circuit, and at the same time reduce the cost of the power supply circuit and the pre-charging circuit.

[0056] Figure 1 is a schematic circuit diagram of a power supply device for supplying power to a control system of a frequency converter according to an embodiment of the present application. Figure 1As shown, the phase-shifting transformer 10 of the frequency converter includes a primary winding 11 arranged on the primary side, the primary winding 11 receives a first voltage; a secondary winding 12 arranged on the secondary side, the secondary winding 12 outputs a second voltage lower than the first voltage; and an auxiliary winding 13 arranged on the secondary side, the auxiliary winding 13 is separated from the secondary winding 12, and outputs a third voltage lower than the first voltage. The secondary winding 12 can be connected to the power unit P of the frequency converter, so that the second voltage output from the secondary winding 12 is provided to the power unit P of the frequency converter.

[0057] Furthermore, if Figure 1 As shown, the power supply device 1 for supplying power to the control system of the inverter includes: a first three-phase AC power supply circuit 20, the first three-phase AC power supply circuit 20 may include an auxiliary winding 13 of a phase-shifting transformer 10, the first three-phase AC power supply circuit 20 includes a first phase line L1, a second phase line L2 and a third phase line L3, and the first three-phase AC power supply circuit 20 supplies power to the control system of the inverter through a third voltage output by the auxiliary winding 13.

[0058] As an example, Figure 1 As shown, the first three-phase AC power supply circuit 20 can further include a first contactor K2, the coil of the first contactor K2 can be connected to the first phase line L1 and the second phase line L2 of the first three-phase AC power supply circuit 20 and connected to the auxiliary winding 13 via the circuit breaker Q2, and the main contacts 1 and 2, 3 and 4, and 5 and 6 of the first contactor K2 are respectively connected to the first phase line L1, the second phase line L2 and the third phase line L3.

[0059] The power supply device 1 may also include a pre-charging circuit 30, which is connected to an external power supply to receive AC power from the external power supply, and the pre-charging circuit 30 is also connected to the first phase line L1, the second phase line L2 and the third phase line L3 of the first three-phase AC power supply circuit 20 to supply power to the auxiliary winding 13 so as to pre-charge the inverter, and the pre-charging circuit 30 and the first three-phase AC power supply circuit 20 are constructed to interlock with each other to allow one of the pre-charging circuit 30 and the first three-phase AC power supply circuit 20 to operate. As an example, the first three-phase AC power supply circuit 20 can provide a voltage of 380V-500V. In this article, the external power supply refers to an external power supply provided on site by the user (customer).

[0060] As an example, Figure 1As shown, the pre-charging circuit 30 may include a charging circuit 31 connected to an external power source and a second contactor K4, the main contacts 1 and 2, 3 and 4, and 5 and 6 of the second contactor K4 are respectively connected to the first phase line L1, the second phase line L2, and the third phase line L3 of the first three-phase AC power supply circuit 20, and the coil of the second contactor K4 is connected to the state contacts 11 and 12 of the first contactor K2. In addition, the coil of the first contactor K2 is also connected to the state contacts 21 and 22 of the second contactor K4, and the state contacts may include a normally open contact and a normally closed contact. Figure 1 In the example shown, the status contact is a normally closed contact.

[0061] Specifically, the pre-charging circuit 30 can receive a pre-charging control signal from its control unit via terminals A and B. After receiving the pre-charging control signal, the coil of the second contactor K4 of the pre-charging circuit 30 is energized and thus attracted, thereby closing the main contacts 1 and 2, 3 and 4, and 5 and 6 of the second contactor K4, so that the AC power received from the external power supply is provided to the auxiliary winding 13 to pre-charge the inverter. At this time, due to the attraction of the coil of the second contactor K4, the normally closed contact of the second contactor K4 changes from the normally closed state to the open state, and the coil of the first contactor K2 is not energized so that the coil of the first contactor K2 is in the open state, that is, the coil of the first contactor K2 switches between attraction and opening according to the state of the state contact of the second contactor K4. At this time, the pre-charging circuit 30 is running, and the first three-phase AC power supply circuit 20 is disconnected from the control system and is in a non-operating state.

[0062] After the pre-charging is completed, the coil of the second contactor K4 loses power and opens, thereby the main contacts 1 and 2, 3 and 4, and 5 and 6 of the second contactor K4 are opened, so that the pre-charging circuit 30 is disabled. At this time, the normally closed contact of the second contactor K4 is restored from the open state to the normally closed state, so that the coil of the first contactor K2 is energized and the coil is attracted, thereby the main contacts 1 and 2, 3 and 4, and 5 and 6 of the first contactor K2 are closed, so that the first three-phase AC power supply circuit 20 is enabled and in operation. Therefore, the pre-charging circuit 30 and the first three-phase AC power supply circuit 20 are interlocked with each other to allow one of the pre-charging circuit 30 and the first three-phase AC power supply circuit 20 to operate.

[0063] Since the auxiliary winding 13 is powered by the pre-charging circuit 30 to pre-charge the inverter, the high voltage impact on the capacitor, rectifier and other devices inside the power unit P connected to the secondary winding 12 during the high voltage application process is prevented, thereby extending the service life of the inverter and improving the reliability of the inverter. In addition, the auxiliary winding 13 of the phase-shifting transformer 10 can be used as both a power supply winding and a pre-charging winding, which simplifies the entire auxiliary power supply circuit and reduces the cost of the power supply circuit and the pre-charging circuit.

[0064] As an example, Figure 1 As shown, the power supply device 1 may further include a second three-phase AC power supply circuit 40 and a switching unit 50 .

[0065] The second three-phase AC power supply circuit 40 may include an external power supply (not shown). The second three-phase AC power supply circuit 40 may have a first phase line L1, a second phase line L2, and a third phase line L3. The second three-phase AC power supply circuit 40 supplies power to the control system of the inverter through the power supply voltage provided by the external power supply, wherein the first three-phase AC power supply circuit 20 and the second three-phase AC power supply circuit 40 are constructed to interlock with each other to supply power to the control system through one of the first three-phase AC power supply circuit 20 and the second three-phase AC power supply circuit 40. The external power supply here and the external power supply for powering the pre-charging circuit 30 may be the same power supply or different power supplies. Figure 1 In the example, the external power source here is the same power source as the external power source that supplies power to the pre-charging circuit 30.

[0066] As an example, the second three-phase AC power supply circuit 40 may also include a third contactor K1, the coil of the third contactor K1 is connected to the first phase line L1 and the second phase line L2 of the second three-phase AC power supply circuit 40 and is connected to the external power supply through the circuit breaker Q1, and the main contacts 1 and 2, 3 and 4, and 5 and 6 of the third contactor K1 are respectively connected to the first phase line L1, the second phase line L2 and the third phase line L3 of the second three-phase AC power supply circuit 40. The coil of the third contactor K1 can be connected to the state contacts 21 and 22 of the first contactor K2, and the first three-phase AC power supply circuit 20 and the second three-phase AC power supply circuit 40 are interlocked with each other through the first contactor K2 and the third contactor K1, wherein the state contact is a normally open contact or a normally closed contact, and in this example, the state contact is a normally closed contact.

[0067] For example, when the coil of the first contactor K2 is attracted so that the state contact of the first contactor K2 changes from the normally closed state to the open state, the coil of the third contactor K1 is not energized so that the coil is in the open state, and thus the main contacts 1 and 2, 3 and 4, and 5 and 6 of the third contactor K1 are in the open state, so that the second three-phase AC power supply circuit 40 is disconnected from the control system and no power is supplied to the control system. At this time, due to the attraction of the coil of the first contactor K2, the main contacts 1 and 2, 3 and 4, and 5 and 6 of the first contactor K2 are closed, so that the first three-phase AC power supply circuit 20 is connected to the control system to supply power to the control system, so that the first three-phase AC power supply circuit 20 and the second three-phase AC power supply circuit 40 are constructed to be interlocked with each other so as to supply power to the control system through one of the first three-phase AC power supply circuit 20 and the second three-phase AC power supply circuit 40. Although the situation in which the first three-phase AC power supply circuit 20 is connected to the control system to supply power to the control system and the second three-phase AC power supply circuit 40 is disconnected from the control system and does not supply power to the control system is described here, the technical personnel in this field can understand the situation in which the second three-phase AC power supply circuit 40 is connected to the control system to supply power to the control system and the first three-phase AC power supply circuit 20 is disconnected from the control system and does not supply power to the control system based on the description here, and it will not be repeated here.

[0068] The switching unit 50 may include a switching contactor K3. Figure 1 In the example of the power supply device shown, the first three-phase AC power supply circuit 20 serves as the main power supply circuit and the second three-phase AC power supply circuit 40 serves as the auxiliary power supply circuit, so that the switching unit 50 is arranged on the side of the phase-shifting transformer (i.e., the side of the first three-phase AC power supply circuit 20). Specifically, the coil of the switching contactor K3 is connected to the first phase line L1 and the second phase line L2 of the first three-phase AC power supply circuit 20 and is connected to the auxiliary winding 13 via the circuit breaker Q2, and the main contacts 1 and 2, 3 and 4, and 5 and 6 of the switching contactor K3 can be respectively connected to the main contacts 1 and 2, 3 and 4, and 5 and 6 of the first contactor K2. The coil of the switching contactor K3 can be connected to the state contacts 11 and 12 of the second contactor K4 of the pre-charging circuit 30, thereby ensuring that the pre-charging circuit 30 and the first three-phase AC power supply circuit 20 are interlocked with each other.

[0069] Furthermore, the coil of the third contactor K1 is also connected to the state contacts 21 and 22 of the switching contactor K3 . In this example, the state contacts are normally closed contacts.

[0070] In this example, the switching contactor K3 can be used to switch the power supply from the second three-phase AC power supply circuit 40 to the control system to the power supply from the first three-phase AC power supply circuit 20. Specifically, the coil of the third contactor K1 is also connected to the normally closed contact of the switching contactor K3, and the coil of the switching contactor K3 is also connected to the state indicating contacts 111 and 112 indicating whether the voltage output by the auxiliary winding of the phase-shifting transformer 10 is restored to a value greater than or equal to a predetermined value, that is, restored to a normal power supply state. When the state indicating contacts 111 and 112 are closed to indicate that the voltage output by the auxiliary winding of the phase-shifting transformer 10 is restored to a normal power supply state, the coil of the switching contactor K3 is energized and thus attracted, thereby closing the main contacts 1 and 2, 3 and 4, and 5 and 6 of the switching contactor K3, so that the first three-phase AC power supply circuit 20 supplies power to the control system. At this time, since the coil of the switching contactor K3 is energized and thus attracted, the normally closed contacts 21 and 22 of the switching contactor K3 are opened, so that the coil of the third contactor K1 loses power and becomes open, thereby the main contacts 1 and 2, 3 and 4, and 5 and 6 of the third contactor K1 are opened to disconnect the second three-phase AC power supply circuit 40 from the control system. Therefore, the switching contactor K3 realizes the switching from the second three-phase AC power supply circuit 40 to the first three-phase AC power supply circuit 20.

[0071] The above describes the situation where the first three-phase AC power supply circuit 20 is used as the main power supply circuit and the second three-phase AC power supply circuit 40 is used as the auxiliary power supply circuit. The configuration where the second three-phase AC power supply circuit 40 is used as the main power supply circuit and the first three-phase AC power supply circuit 20 is used as the auxiliary power supply circuit can also be implemented. In this case, the switching contactor K3 is arranged on one side of the second three-phase AC power supply circuit 40 and the coil of the switching contactor K3 can be connected to the first phase line L1 and the second phase line L2 of the second three-phase AC power supply circuit 40, and the coil of the first contactor K2 can be connected to the status contact of the switching contactor K3. The switching contactor K3 is used to switch the power supply from the first three-phase AC power supply circuit 20 to the control system to the power supply from the second three-phase AC power supply circuit 40 to the control system.

[0072] As an example, the power supply device 1 may further include an output circuit 60, the output circuit 60 including a first output terminal 1, a second output terminal 3, and a third output terminal 5. Additionally, the output circuit 60 may further include a first auxiliary output terminal 2 connected to the first output terminal 1, a second auxiliary output terminal 4 connected to the second output terminal 3, and a third auxiliary output terminal 6 connected to the third output terminal 5.

[0073] Additionally or alternatively, the power supply device 1 may further include an electromagnetic compatibility filter circuit 70, which is connected to the first auxiliary output terminal 2, the second auxiliary output terminal 4 and the third auxiliary output terminal 6 of the output circuit 60. The first phase line L1 of the first three-phase AC power supply circuit 20 and the first phase line L1 of the second three-phase AC power supply circuit 40 are connected to the first output terminal 1, the second phase line L2 of the first three-phase AC power supply circuit 20 and the second phase line L2 of the second three-phase AC power supply circuit 40 are connected to the second output terminal 3, and the third phase line L3 of the first three-phase AC power supply circuit 20 and the third phase line L3 of the second three-phase AC power supply circuit 40 are connected to the third output terminal 5.

[0074] Therefore, the first three-phase AC power supply circuit 20 and the second three-phase AC power supply circuit 40 are combined into one in the output circuit 60, that is, the two inputs are combined into one output. At the same time, only one electromagnetic compatibility filter circuit 70 needs to be added, rather than adding two electromagnetic compatibility filter circuits 70 to the two inputs. This saves space and cost. The electromagnetic compatibility filter circuit 70 is an optional circuit. If there is no EMC filter, the entire circuit is also valid.

[0075] As an example, the first three-phase AC power supply circuit 20 and the second three-phase AC power supply circuit 40 can provide a voltage of 380V or 400V.

[0076] As an example, Figure 1 As shown, the control system may include a fan control circuit MC, which may be connected to the electromagnetic compatibility filter circuit 70 via a terminal bus 80 to draw a three-phase voltage via the terminal bus 80. Specifically, the terminal bus 80 may include a group of three terminals 7, 8, and 9 that receive a three-phase voltage from the output circuit 60, wherein one fan control circuit is connected to a group of three terminals. Alternatively, a group of three terminals 7, 8, and 9 may be expanded to multiple groups of three terminals to connect multiple fan control circuits. Thus, the terminal bus 80 can be expanded to expand the number of fan control circuits connected to the terminal bus 80, thereby expanding the number of connected fans.

[0077] As an example, the terminal bus 80 may also include additional terminals 10 and 11 connected to terminals 7 and 8, respectively, and the power supply device 1 may also include a third power supply circuit 90 connected to the additional terminals 10 and 11, so that the third power supply circuit 90 can draw two-phase voltages of the three-phase voltage from the additional terminals 10 and 11 of the terminal bus 80 to provide the control system with a two-phase voltage with a voltage lower than the three-phase voltage. For example, the third power supply circuit 90 can be a 220V, 50HZ power supply circuit, thereby providing a voltage of 220V to the control system.

[0078] As an example, the power supply device 1 may also include a voltage acquisition circuit 100, which may be directly connected to the first phase line L1, the second phase line L2 and the third phase line L3 of the first three-phase AC power supply circuit 20 to monitor the first voltage on the primary side of the phase-shifting transformer 10 by acquiring the third voltage output by the first phase line L1, the second phase line L2 and the third phase line L3. Thus, the auxiliary winding of the phase-shifting transformer can be fully utilized, that is, the acquisition of the primary side voltage of the phase-shifting transformer is realized, and high and low voltage isolation can be achieved. This can reduce the problems of insulation, electrical clearance, etc. caused by direct high-voltage voltage acquisition. Moreover, the cost of the entire voltage acquisition circuit and the volume occupied by components can be reduced.

[0079] The present application also provides a frequency converter, which includes: Figure 1 The fan control circuit MC shown is used as a control system or a part of a control system and Figure 1 The power supply device shown is used to supply power to the control system.

[0080] The above is a description of a power supply device for supplying power to a control system of a frequency converter according to an embodiment of the present application and a frequency converter including such a power supply device. The power supply device can supply power to the control system of the frequency converter by utilizing an auxiliary winding added on the secondary side of a phase-shifting transformer, thereby reducing the need for the customer to provide auxiliary AC power on site, and the power supply voltage of the auxiliary winding on the secondary side of the phase-shifting transformer can be adjusted according to the fan voltage. The power supply device may also include a redundant power supply. Since the first three-phase AC power supply circuit and the second three-phase AC power supply circuit are interlocked with each other, only one of them supplies power to the control system. Therefore, it is possible to switch to another power supply circuit after power is lost in one power supply circuit, thereby avoiding the risk of power loss of the entire control power supply due to damage to a single power supply, thereby improving the power supply reliability and operating stability of the frequency converter.

[0081] The specific working mode of the power supply device of the utility model according to this embodiment is described below:

[0082] The external power supply side provides a three-phase power supply, and the pre-charging circuit 30 receives the pre-charging control signal via terminals A and B, so that the coil of the second contactor K4 is energized and attracted, and the main contacts 1 and 2, 3 and 4, and 5 and 6 of the second contactor K4 are closed, so that the charging circuit 31 is connected to the first phase line L1, the second phase line L2, and the third phase line L3, so that the charging circuit 31 provides the power received from the external power supply to the auxiliary coil, thereby energizing the auxiliary coil, and charging the inverter. At this time, the coil of the first contactor K2 is open, that is, the first three-phase AC power supply circuit 20 is not running. At the same time, the voltage acquisition circuit 100 always monitors the charging voltage.

[0083] After the pre-charging is completed, the coil of the second contactor K4 loses power, so that the coil of the second contactor K4 opens, so that the main contacts 1 and 2, 3 and 4, and 5 and 6 of the second contactor K4 are disconnected, and the pre-charging circuit 30 is disconnected from the auxiliary coil. At this time, the high-voltage power supply on the primary side of the phase-shifting transformer 10 is closed, the phase-shifting transformer 10 is energized, and the coil of the first contactor K2 of the first three-phase AC power supply circuit 20 as the main power supply circuit is attracted, so that the main contacts 1 and 2, 3 and 4, 5 and 6 of the first contactor K2 are closed, thereby realizing that the auxiliary winding of the phase-shifting transformer supplies power to the control system. In this case, since the coil of the first contactor K2 is attracted, its normally closed contact becomes open, and the coil of the third contactor K1 of the second three-phase AC power supply circuit 40 as the auxiliary power supply circuit is not powered, so that the coil of the third contactor K1 remains open. In this state, the external power supply is used as the starting power supply of the inverter.

[0084] When the first three-phase AC power supply circuit 20 cannot provide enough voltage to the control system, for example, when the voltage output by the auxiliary winding of the phase-shifting transformer 10 is lower than the predetermined threshold value (undervoltage), the coil of the first contactor K2 loses power and becomes open. Then, due to the opening of the coil of the first contactor K2, the state contact of the first contactor K2 is restored to the closed state and the coil of the switching contactor K3 is in the open state, so that the state contact of the switching contactor K3 remains in the closed state, thereby the coil of the third contactor K1 of the second three-phase AC power supply circuit 40 is energized so that the coil of the third contactor K1 is attracted, so that the main contacts 1 and 2, 3 and 4, 5 and 6 of the third contactor K1 are closed, thereby realizing the switching from the auxiliary winding power supply of the phase-shifting transformer to the external power supply to the control system. In this state, the external power supply is used as a redundant auxiliary power supply.

[0085] When the status indication contacts 111 and 112 indicate that the voltage output by the auxiliary winding of the phase-shifting transformer 10 has returned to the normal power supply voltage, the coil of the switching contactor K3 is energized. Due to the energization of the coil of the switching contactor K3, the main contacts 1 and 2, 3 and 4, 5 and 6 of the switching contactor K3 are closed, thereby supplying power to the control system from the auxiliary winding of the phase-shifting transformer. At the same time, due to the energization of the coil of the switching contactor K3, the status contact of the switching contactor K3 becomes open, thereby de-energizing the third contactor K1, thereby opening the main contacts 1 and 2, 3 and 4, 5 and 6 of the third contactor K1, thereby disconnecting the second three-phase AC power supply circuit 40 from the control system and no longer supplying power to the control system, thereby switching from the external power supply to the auxiliary winding of the phase-shifting transformer to supply power to the control system.

[0086] In the above process, the voltage acquisition circuit 100 always acquires the third voltage in real time through the auxiliary winding, thereby monitoring the high-voltage side voltage.

[0087] The above operation mode is a situation where the first three-phase AC power supply circuit 20 serves as the main power supply circuit and the second three-phase AC power supply circuit 40 serves as the auxiliary power supply circuit. For the configuration where the second three-phase AC power supply circuit 40 serves as the main power supply circuit and the first three-phase AC power supply circuit 20 serves as the auxiliary power supply circuit, technicians in this field can make modifications based on the contents disclosed in this application to obtain and practice the specific configuration and working mode of the power supply device.

[0088] The power supply device for supplying power to the control system of the frequency converter according to the embodiment of the present application has at least the following advantages over the prior art:

[0089] 1. The first three-phase AC power supply circuit and the second three-phase AC power supply circuit are interlocked with each other, and only one of them supplies 380Vac or 400Vac to the control system, and can switch to the other power supply circuit after power is lost in one power supply circuit.

[0090] 2. Whether the auxiliary winding of the phase-shifting transformer or the customer power supply is used as the main power supply circuit can be determined based on whether the switching relay is set on the phase-shifting transformer side or the customer power supply side, thereby achieving circuit flexibility.

[0091] 3. The pre-charging circuit and the second three-phase AC power supply circuit share a customer power supply, and the pre-charging circuit and the first three-phase AC power supply circuit share an output, namely the three-phase line of the auxiliary winding, thereby reducing the input loop at the customer site and also reducing the cost and space of the transformer winding of the pre-charging circuit and the second three-phase AC power supply circuit.

[0092] 4. The pre-charging circuit and the second three-phase AC power supply circuit are interlocking circuits to ensure that only one circuit is running at different times.

[0093] 5. The first three-phase AC power supply circuit and the second three-phase AC power supply circuit are combined into one in the output circuit, that is, the two inputs are combined into one output. At the same time, only one EMC filter needs to be added, instead of adding two EMC filters to the two inputs. This saves space and cost. The EMC filter is an optional circuit. If there is no EMC filter, the entire circuit is also valid.

[0094] 6. The third power supply circuit can provide 220V power supply to the system. The third power supply circuit has two inputs, that is, 2 inputs and one output, which can ensure the input of multiple power supplies and provide more reliable power input for the control system.

[0095] 7. The number of fans can be expanded through the terminal block according to the required number of fans.

[0096] 8. The first three-phase AC power supply circuit can exist alone, that is, it can be realized even without the second three-phase AC power supply circuit. At this time, there is an additional advantage that the secondary side power supply voltage of the phase-shifting transformer can be adjusted according to the wind turbine voltage. That is, it is not just 380V / 400V, it can be 415V or other voltage values. The advantage is that when the wind turbine voltage is 415V, but the customer side only has 380V or 400V, the customer does not need to add a separate step-up transformer to change the voltage. Reduce the customer's investment and space usage.

[0097] In the above embodiments of the present application, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0098] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only illustrative. The above are only preferred implementations of this application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of this application, and these improvements and modifications should also be regarded as the protection scope of this application.

Claims

1. A power supply device for supplying power to a control system of a frequency converter, the frequency converter comprising a phase-shifting transformer (10), the phase-shifting transformer (10) comprising a primary winding (11) arranged on a primary side, the primary winding (11) receiving a first voltage; and a secondary winding (12) arranged on a secondary side, the secondary winding (12) outputting a second voltage lower than the first voltage, characterized in that: The phase-shifting transformer (10) further comprises an auxiliary winding (13) arranged on the secondary side, the auxiliary winding (13) being arranged separately from the secondary winding (12), and the auxiliary winding (13) outputting a third voltage lower than the first voltage, the power supply device comprising a first three-phase AC power supply circuit (20), the first three-phase AC power supply circuit (20) comprising the auxiliary winding (13) of the phase-shifting transformer, the first three-phase AC power supply circuit (20) having a first phase line, a second phase line and a third phase line, the first three-phase AC power supply circuit (20) supplies power to the control system of the inverter via the third voltage output by the auxiliary winding (13).

2. The power supply device for supplying power to a control system of a frequency converter according to claim 1, characterized in that: The power supply device further comprises a pre-charging circuit (30), wherein the pre-charging circuit (30) is connected to the first phase line, the second phase line and the third phase line of the first three-phase AC power supply circuit (20) to supply power to the auxiliary winding (13) so as to pre-charge the inverter, and the pre-charging circuit (30) and the first three-phase AC power supply circuit (20) are constructed to be interlocked with each other to allow one of the pre-charging circuit (30) and the first three-phase AC power supply circuit (20) to operate.

3. The power supply device for supplying power to a control system of a frequency converter according to claim 1, characterized in that: The power supply device further comprises a second three-phase AC power supply circuit (40), the second three-phase AC power supply circuit (40) comprises an external power supply, the second three-phase AC power supply circuit (40) has a first phase line, a second phase line and a third phase line, the second three-phase AC power supply circuit (40) supplies power to the control system of the inverter through a power supply voltage provided by the external power supply, wherein the first three-phase AC power supply circuit (20) and the second three-phase AC power supply circuit (40) are constructed to be interlocked with each other so as to supply power to the control system through one of the first three-phase AC power supply circuit (20) and the second three-phase AC power supply circuit (40).

4. The power supply device for supplying power to a control system of a frequency converter according to claim 3, characterized in that: The power supply device further comprises a switching contactor (K3), wherein the switching contactor (K3) is used to switch the power supply from the first three-phase AC power supply circuit (20) to the control system to the second three-phase AC power supply circuit (40), or to switch the power supply from the second three-phase AC power supply circuit (40) to the control system to the first three-phase AC power supply circuit (20).

5. The power supply device for supplying power to a control system of a frequency converter according to claim 3, characterized in that: The power supply device further comprises an output circuit (60), the output circuit (60) comprising a first output terminal, a second output terminal and a third output terminal, the first phase line of the first three-phase AC power supply circuit (20) and the first phase line of the second three-phase AC power supply circuit (40) are connected to the first output terminal, the second phase line of the first three-phase AC power supply circuit (20) and the second phase line of the second three-phase AC power supply circuit (40) are connected to the second output terminal, and the third phase line of the first three-phase AC power supply circuit (20) and the third phase line of the second three-phase AC power supply circuit (40) are connected to the third output terminal.

6. The power supply device for supplying power to a control system of a frequency converter according to claim 5, characterized in that: The control system is connected to the output circuit (60) through a terminal busbar (80) to draw a three-phase voltage via the terminal busbar (80).

7. The power supply device for supplying power to a control system of a frequency converter according to claim 6, characterized in that: The power supply device also includes a third power supply circuit (90), which draws two-phase voltages of the three-phase voltage from the terminal bus (80) to provide the control system with a two-phase voltage whose voltage is lower than the three-phase voltage.

8. The power supply device for supplying power to a control system of a frequency converter according to claim 1, characterized in that: The power supply device further comprises a voltage collection circuit (100), wherein the voltage collection circuit (100) is connected to a first phase line, a second phase line and a third phase line of the first three-phase AC power supply circuit (20) to collect the third voltage output by the auxiliary winding of the phase-shifting transformer.

9. The power supply device for supplying power to a control system of a frequency converter according to claim 2, characterized in that: The first three-phase AC power supply circuit (20) further comprises a first contactor (K2), the pre-charging circuit (30) comprises a second contactor (K4), the pre-charging circuit (30) is connected to the first phase line, the second phase line and the third phase line of the first three-phase AC power supply circuit (20) via the second contactor (K4), the second contactor (K4) is connected to the status contact of the first contactor (K2), the first contactor (K2) is connected to the status contact of the second contactor (K4), the pre-charging circuit (30) and the first three-phase AC power supply circuit (20) are interlocked with each other via the first contactor (K2) and the second contactor (K4), wherein the status contact is a normally open contact or a normally closed contact.

10. The power supply device for supplying power to a control system of a frequency converter according to claim 4, characterized in that: The first three-phase AC power supply circuit (20) further comprises a first contactor (K2), and the second three-phase AC power supply circuit (40) further comprises a third contactor (K1), the first contactor (K2) being connected to the first phase line and the second phase line of the first three-phase AC power supply circuit (20) and being connected to the status contact of the third contactor (K1), the third contactor (K1) being connected to the first phase line and the second phase line of the second three-phase AC power supply circuit (40) and being connected to the status contact of the first contactor (K2), the first three-phase AC power supply circuit (20) and the second three-phase AC power supply circuit (40) being interlocked with each other through the first contactor (K2) and the third contactor (K1), wherein the status contact is a normally open contact or a normally closed contact.

11. The power supply device for supplying power to a control system of a frequency converter according to claim 10, characterized in that: When the first three-phase AC power supply circuit (20) serves as the main power supply circuit and the second three-phase AC power supply circuit (40) serves as the auxiliary power supply circuit, the switching contactor (K3) is connected to the first phase line and the second phase line of the first three-phase AC power supply circuit (20), and the third contactor (K1) is also connected to the status contact of the switching contactor (K3). The switching contactor (K3) is used to switch the power supply from the second three-phase AC power supply circuit (40) to the first three-phase AC power supply circuit (20).

12. The power supply device for supplying power to a control system of a frequency converter according to claim 10, characterized in that: When the second three-phase AC power supply circuit (40) serves as a main power supply circuit and the first three-phase AC power supply circuit (20) serves as an auxiliary power supply circuit, the switching contactor (K3) is connected to a first phase line and a second phase line of the second three-phase AC power supply circuit (40), and the first contactor (K2) is also connected to a status contact of the switching contactor (K3). The switching contactor (K3) is used to switch power supply from the first three-phase AC power supply circuit to the second three-phase AC power supply circuit.

13. A frequency converter, characterized in that: The frequency converter comprises a control system and a power supply device according to any one of claims 1 to 12, wherein the power supply device is used to supply power to the control system.

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