A medium-high voltage fast electronic switch unit and a control system thereof

Abstract

The utility model relates to a kind of middle-high voltage fast electronic switch unit and its control system, belong to power electronics field.Electronic switch unit includes multiple groups of thyristor anti-parallel component with blocking capacitor voltage-sharing circuit in series, and thyristor anti-parallel component is connected in series by radiator;Resistance-capacitance voltage-sharing circuit is connected in parallel in each group of thyristor anti-parallel component.Electronic switch unit is controlled by the system of overvoltage protector, temperature detection device, current detection device, PECS controller and thyristor trigger device.Electronic switch unit is connected with overvoltage protector, and thyristor trigger device is connected with PECS controller and electronic switch unit respectively;Temperature detection device and current detection device are connected with PECS controller respectively.The utility model can quickly respond switch instruction, realizes high-low voltage electrical isolation, and guarantees equipment and personnel safety.

Description

Technical Field

[0001] This utility model belongs to the field of power electronics and relates to a medium- and high-voltage fast electronic switching unit and its control system. Background Technology

[0002] In today's power systems and high-end industrial applications, the performance of switchgear plays a crucial role in the system's operational efficiency and safety. Traditional mechanical switches suffer from numerous technical bottlenecks due to limitations in their operating principle. Ordinary mechanical switches have slow response times, typically tens of milliseconds or even longer, making it difficult to meet the demands of rapid switching. Furthermore, mechanical switches have a limited number of switching cycles; prolonged and frequent use leads to contact wear and increased contact resistance, consequently affecting the switch's reliability and lifespan. These issues make mechanical switches unsuitable for applications requiring rapid and frequent switching, especially in high-voltage and high-frequency AC power supply environments.

[0003] In recent years, with the development of power electronics technology, electronic switches have gradually become an ideal replacement for traditional mechanical switches. In some special applications, such as photovoltaic grid-connected and off-grid systems and maglev train systems, the application of electronic switches is particularly crucial. Grid-connected and off-grid photovoltaic systems require rapid power switching under different operating modes to ensure the continuity and stability of power supply. The long stator system of maglev trains places even more stringent requirements on the performance of switching equipment. This system not only requires electronic switches to withstand high voltages of up to 3-10kV, but also to achieve rapid shutdown under AC power of 600-1000Hz. This rapid shutdown capability is essential for ensuring the safe operation and precise control of maglev trains.

[0004] However, existing electronic switching technologies still have significant shortcomings when faced with the requirement of rapid shutdown under such high-voltage and high-frequency AC power supplies. Conventional electronic switches, such as ordinary thyristors, can achieve rapid switching to a certain extent, but their shutdown capability is limited under high-voltage and high-frequency AC power conditions. Utility Model Content

[0005] In view of this, the purpose of this utility model is to provide a medium- and high-voltage fast electronic switching unit and its control system. The electronic switching unit is constructed by using KK-type thyristors and RC voltage equalization circuits to meet the requirements of fast switching and high reliability in special application scenarios such as photovoltaic grid-connected and off-grid systems and magnetic levitation train stator systems.

[0006] To achieve the above objectives, the first aspect of this utility model provides a medium-high voltage fast electronic switching unit, which includes multiple sets of series-connected anti-parallel thyristor assemblies with RC voltage equalization circuits, the anti-parallel thyristor assemblies being connected in series through heat sinks; wherein, each set of anti-parallel thyristor assemblies includes two KK-type fast thyristors connected in anti-parallel; a static voltage equalization resistor is connected in parallel next to each set of anti-parallel thyristor assemblies, and a dynamic voltage equalization resistor and a dynamic voltage equalization capacitor connected in series are also connected in parallel to each set of anti-parallel thyristor assemblies.

[0007] Among them, the turn-off time of the KK type fast thyristor is less than or equal to 200μs, making the electronic switching unit suitable for high-frequency AC power supplies of 200-1000Hz.

[0008] The second aspect of this utility model provides a control system for controlling the electronic switching unit described in the first aspect. The system includes an overvoltage protector, a temperature detection device, a current detection device, a PECS controller, and a thyristor triggering device.

[0009] The overvoltage protector is connected to the electronic switching unit to prevent the electronic switching unit from being damaged by external overvoltage; the thyristor triggering device is connected to the PECS controller and the electronic switching unit respectively; the temperature detection device and the current detection device are connected to the PECS controller respectively.

[0010] Furthermore, the thyristor triggering device includes a power supply board and a trigger board; each trigger board is connected to a thyristor, and each power supply board is connected to all the trigger boards in a thyristor series assembly of one phase.

[0011] Furthermore, the temperature detection device includes a temperature measuring element, a wireless receiver, and a 485 signal to fiber optic signal module connected in sequence.

[0012] Furthermore, the current detection device includes an amplifier circuit and a CPLD (Programmable Logic Device) chip connected in sequence.

[0013] Furthermore, the PECS controller has a built-in fiber optic communication port for receiving and transmitting optical signals. The fiber optic communication port includes a pair of fiber optic receivers and fiber optic transmitters with a rate of 160 MBd or higher. The wavelengths of the fiber optic receivers and fiber optic transmitters are selected and configured according to the required transmission distance.

[0014] The fiber optic communication port communicates with external devices using the IEC60044-8 protocol. The communication content includes switching commands, equipment operating status such as overcurrent and overtemperature, and the switching command response rate is less than or equal to 10μs.

[0015] Furthermore, the PECS controller is connected to the temperature detection device, current detection device, and thyristor triggering device via optical fiber.

[0016] The beneficial effects of this utility model are as follows: This utility model proposes a medium-high voltage fast electronic switching unit and its control system, effectively overcoming the problems of traditional mechanical switches and conventional electronic switches in high-voltage, high-frequency applications. In this utility model, the electronic switching unit adopts a modular multi-group thyristor series structure, which has good voltage and current level expansion capability. Furthermore, it combines KK-type thyristors and RC voltage equalization circuits, enabling the electronic switching unit to be applicable to high-frequency AC power supplies and achieve fast and reliable shutdown operation, flexibly adapting to the needs of different medium-high voltage systems.

[0017] Furthermore, the control system proposed in this invention features high integration and fast response speed. Utilizing high-speed fiber optic communication for command transmission and status monitoring, it can quickly respond to switching commands, with a communication cycle as short as 40μs, ensuring extremely rapid response to switching commands and real-time system control. Temperature and current detection devices are electrically isolated via fiber optics, ensuring the safety of equipment and personnel in high-voltage environments. The overall control system has a compact structure, making it suitable for space-constrained industrial applications. It features no mechanical wear, long lifespan, and maintenance-free operation, meeting the stringent requirements of high-voltage, high-frequency AC systems such as the stator system of maglev trains for rapid switching and reliable operation.

[0018] Other advantages, objectives, and features of this invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination and study, or may be learned from practice of this invention. The objectives and other advantages of this invention can be realized and obtained through the following description. Attached Figure Description

[0019] To make the objectives, technical solutions, and advantages of this utility model clearer, the preferred embodiments of this utility model will be described in detail below with reference to the accompanying drawings, wherein:

[0020] Figure 1 This is a schematic diagram of the control system structure of a medium- and high-voltage fast electronic switching unit provided in an embodiment of the present invention;

[0021] Figure 2 This is a schematic diagram of a medium-high voltage fast electronic switching unit structure provided in an embodiment of the present invention;

[0022] Figure 3 This is a schematic diagram of the current detection device.

[0023] Reference numerals: 1-Electronic switching unit; 2-Overvoltage protector; 3-Temperature detection device; 4-Current detection device; 5-PECS controller; 6-Fiber optic communication port; 7-Thyristor triggering device; 8-Fiber optic cable. Detailed Implementation

[0024] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this utility model. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0025] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the present invention. To better illustrate the embodiments of the present invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0026] In the accompanying drawings of this utility model, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this utility model. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0027] Example 1

[0028] This embodiment provides a medium-to-high voltage fast electronic switching unit, such as... Figure 2 As shown, the electronic switching unit includes multiple sets of series-connected anti-parallel thyristor components with RC voltage equalization circuits, wherein the anti-parallel thyristor components are connected in series through heat sinks.

[0029] In this electronic switching unit, the appropriate number of thyristor anti-parallel components can be selected for series connection according to the voltage level, thus making it suitable for voltage levels in different scenarios.

[0030] In this embodiment, for the 6kV / 700Hz frequency voltage electronic switchgear, four sets of anti-parallel thyristor assemblies are selected and connected in series. Each set of anti-parallel thyristor assemblies uses two 5000V high-voltage KK-type fast thyristors connected in anti-parallel to meet the application requirements of the 6kV fast electronic switchgear. Furthermore, the voltage level can be further increased by adding more sets of series-connected anti-parallel assemblies, and the current level can also be increased by changing the thyristor selection.

[0031] To enable the overall circuit to withstand higher voltages and thus be used in medium- and high-voltage power supply systems, this embodiment also includes a resistor-capacitor (RC) voltage equalization circuit connected in parallel next to the anti-parallel thyristor assembly in each group. The RC voltage equalization circuit includes a static voltage equalization resistor R. d The static voltage equalization resistor R and the dynamic voltage equalization capacitor C. The static voltage equalization resistor R... d To ensure voltage balance of the thyristor elements under blocking conditions, they are connected in parallel to each group of anti-parallel thyristor components; the dynamic voltage equalization resistor R and the dynamic voltage equalization capacitor C are connected in series and then in parallel with each group of anti-parallel thyristor components.

[0032] Example 2

[0033] This embodiment provides a control system for a medium- and high-voltage fast electronic switching unit, such as... Figure 1 As shown, the system includes an electronic switch unit 1, an overvoltage protector 2, a temperature detection device 3, a current detection device 4, a PECS controller 5, a high-speed fiber optic communication port 6, and a thyristor triggering device 7.

[0034] The electronic switch unit 1 is electrically connected to the overvoltage protector 2, and is also signal-connected to the thyristor triggering device 7. The temperature detection device 3, the current detection device 4, and the thyristor triggering device 7 are all signal-connected to the PECS controller 5. The high-speed fiber optic communication port 6 is integrated into the PECS controller 5.

[0035] Electronic switch unit 1 is connected to overvoltage protector 2, which prevents external overvoltage from damaging electronic switch unit 1.

[0036] The temperature detection device 3 includes a temperature sensing element, a wireless receiver, and a 485 signal to fiber optic signal conversion module. The temperature detection device 3 first converts the temperature signal into a wireless signal through the temperature sensing element for transmission, and then converts the temperature signal transmitted by the temperature sensing element into a Modbus-RTU protocol frame signal through the wireless receiver. Subsequently, the wireless receiver transmits the protocol frame signal to the PECS controller 5 through the 485 to fiber optic signal conversion module.

[0037] like Figure 3As shown, the current detection device 3 includes a multi-channel amplifier circuit and a CPLD chip. The current detection device 3 first amplifies the received analog signal through the amplifier circuit, then encodes the analog signal into a serial digital signal with an identification frame header through the CPLD chip, and transmits the digital signal to the PECS controller 5 through the optical fiber 8.

[0038] The function of fiber optic cable 8 is to achieve safe isolation between the high-voltage system and the low-voltage control system.

[0039] The PECS controller 5 is based on an FPGA and DSP, featuring optional communication ports that support various common industrial communication protocols and 24 pairs of programmable fiber optic I / O interfaces. The FPGA option is Cyclone V-5CEBA4F23C8, and the DSP option is TMS320C28346. The PECS controller 5 processes the fiber optic signals from the temperature detection device 2 and the current detection device 3 to obtain the over-temperature, over-current, and other fault states of the electronic switching unit.

[0040] The PECS controller 5 communicates with external devices via a high-speed fiber optic communication port 6, using a custom frame protocol based on IEC 60044-8. Communication content includes, but is not limited to, switching commands, device fault status, and communication cycle settings.

[0041] The PECS controller 5 outputs a corresponding trigger pulse through the optical fiber 8 based on the received external device instructions or the device fault status obtained by its own processing.

[0042] In this embodiment, the high-speed optical fiber communication port 6 uses an optical fiber receiver HFBR-1414Z and an optical fiber transmitter AFBR-2418TZ. The optical fiber 8 used for communication is ST-ST multimode optical fiber with a wavelength of 820nm and a maximum link distance of 2.7km.

[0043] The thyristor triggering device 7 includes a power supply board and a trigger board. Each trigger board is connected to an anti-parallel thyristor, and each power supply board is connected to all trigger boards in a single-phase thyristor series assembly. The power supply board synchronously transmits the pulse signal sent from the PECS controller 5 to the trigger boards of all thyristors in the connected single-phase thyristor series assembly and provides drive power to the trigger boards. The trigger boards convert the optical signal into an electrical signal and output it to the PK and PG terminals of the thyristors, ensuring that the thyristors in the series assembly are turned on synchronously.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of this technical solution, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A medium-high voltage fast electronic switching unit, characterized in that, It includes multiple sets of series-connected anti-parallel thyristor components with RC voltage equalization circuits, which are connected in series through heat sinks; each set of anti-parallel thyristor components includes two KK-type fast thyristors connected in anti-parallel; a static voltage equalization resistor is connected in parallel next to each set of anti-parallel thyristor components, and a dynamic voltage equalization resistor and a dynamic voltage equalization capacitor are connected in parallel in series.

2. A control system for the electronic switching unit of claim 1, characterized in that, The system includes an overvoltage protector, a temperature detection device, a current detection device, a PECS controller, and a thyristor triggering device; the overvoltage protector is connected to the electronic switching unit to prevent the electronic switching unit from being damaged by external overvoltage. The thyristor triggering device is connected to the PECS controller and the electronic switching unit respectively; the temperature detection device and the current detection device are connected to the PECS controller respectively.

3. The control system according to claim 2, characterized in that, The thyristor triggering device includes a power supply board and a trigger board; each trigger board is connected to a thyristor, and each power supply board is connected to all the trigger boards in the thyristor series assembly of one phase.

4. The control system according to claim 2, characterized in that, The temperature detection device includes a temperature measuring element, a wireless receiver, and a 485 signal to fiber optic signal module connected in sequence.

5. The control system according to claim 2, characterized in that, The current detection device includes an amplifier circuit and a CPLD chip connected in sequence.

6. The control system according to claim 2, characterized in that, The PECS controller has a built-in fiber optic communication port for receiving and transmitting light signals.

7. The control system according to claim 6, characterized in that, The PECS controller is connected to the temperature detection device, current detection device, and thyristor triggering device via optical fiber.

Images