Flexible direct current converter valve and sub-module full-voltage power supply device thereof

Abstract

The invention relates to the technical field of converter valve sub-module power supply, and discloses a flexible direct current converter valve and a sub-module full-voltage power supply device thereof, the device comprises a high-voltage power supply and a low-voltage power supply, the high-voltage power supply and the low-voltage power supply are both used for power supply connection with an SCE control panel and a GDU drive board, and the high-voltage power supply and the low-voltage power supply are both energy-taking power supplies. The low-voltage power supply is used for working when the voltage of the sub-module is lower than a set voltage value and higher than a safe voltage and converting the current voltage of the sub-module into the working voltage of the SCE control board and the GDU driving board, and the high-voltage power supply is used for working when the voltage of the sub-module is higher than the set voltage value and converting the current voltage of the sub-module into the working voltage of the GDU driving board. And converting the current sub-module voltage into the working voltage of the SCE control board and the GDU driving board. According to the invention, the operation of continuously detecting the voltage value of the sub-module in the process of continuously reducing the voltage of the sub-module is simplified.

Description

Technical Field

[0001] The present invention relates to the technical field of power supply for converter valve submodules, and in particular to a flexible direct current converter valve and a full-voltage power supply device for its submodules. Background Art

[0002] In the context of new power systems, the proportion of renewable energy generation is increasing year by year. However, the intermittent and random fluctuations of renewable energy generation make it prone to grid fluctuations when integrated into the grid, placing high demands on the grid's self-regulation capabilities. The high flexibility, stability, and adaptability of HVDC Flexible technology play a significant role in addressing the grid fluctuations easily caused by the integration of renewable energy generation.

[0003] Because flexible DC transmission equipment is relatively large and places increasingly stringent demands on its components, maintenance procedures necessitate monitoring its operation at different voltages. Traditionally, maintenance procedures utilize only a high-voltage power supply to power the SCE control panel. This high-voltage power supply, acting as an energy source, converts the high voltage within the submodules into a low voltage to power the SCE control panel. This power supply eliminates the need for additional low-voltage power supply equipment for the SCE control panel. However, in practice, due to the operating principle of the high-voltage power supply, it can only output power when the external voltage (e.g., the submodule) exceeds a certain limit. For example, in actual use, if the submodule voltage is greater than 350V, the SCE control board will only be powered when the input voltage of the high-voltage power supply reaches 350V. When the submodule voltage is lower than 350V (for example, during submodule maintenance and testing), the input voltage of the high-voltage power supply cannot reach the limit value of 350V, and the high-voltage power supply no longer powers the SCE control board. As a result, the SCE control board can no longer monitor the submodule voltage. The operator can only monitor the submodule voltage value through a multimeter. The operation is complicated and cumbersome, and there is a risk of electric shock. Summary of the Invention

[0004] The purpose of the present invention is to provide a flexible DC converter valve and a full-voltage power supply device for its submodules, which aims to solve the problem that the submodule voltage monitoring process is complicated when the voltage of the existing converter valve submodule is lower than the set voltage value.

[0005] In order to solve the above technical problems, the present invention provides a full-voltage power supply device for the sub-module of a flexible direct current converter valve. The device includes a high-voltage power supply and a low-voltage power supply. Both the high-voltage power supply and the low-voltage power supply are used to power the SCE control board and the GDU drive board. Both the high-voltage power supply and the low-voltage power supply are energy-taking power sources, and both take energy from the sub-module. The low-voltage power supply is used to work when the sub-module voltage is lower than the set voltage value and higher than the safety voltage, and convert the current sub-module voltage into the working voltage of the SCE control board and the GDU drive board. The high-voltage power supply is used to work when the sub-module voltage is higher than the set voltage value, and convert the current sub-module voltage into the working voltage of the SCE control board and the GDU drive board.

[0006] Furthermore, the set voltage value is the lowest operating voltage for the high voltage power supply to perform voltage conversion.

[0007] Furthermore, it also includes a trigger switch, which is used to switch the high-voltage power supply or low-voltage power supply to the sub-module according to the sub-module voltage under the control of the SCE control board, and convert the current sub-module voltage into the operating voltage of the SCE control board and the GDU driver board.

[0008] Furthermore, the low-voltage power supply and the high-voltage power supply both adopt a DC / DC circuit structure.

[0009] A flexible DC converter valve includes a submodule circuit, an SCE control board, a GDU drive board and a high-voltage power supply, and also includes a low-voltage power supply. The high-voltage power supply and the low-voltage power supply are both used to supply power to the SCE control board and the GDU drive board. The high-voltage power supply and the low-voltage power supply are both energy-taking power supplies, and both take energy from the submodule. The low-voltage power supply is used to operate when the submodule voltage is lower than a set voltage value and higher than a safety voltage, and convert the current submodule voltage into an operating voltage of the SCE control board and the GDU drive board. The high-voltage power supply is used to operate when the submodule voltage is higher than the set voltage value, and convert the current module voltage into an operating voltage of the SCE control board and the GDU drive board.

[0010] Furthermore, the set voltage value is the lowest operating voltage for voltage conversion of high voltage electricity.

[0011] Furthermore, it also includes a trigger switch. The SCE control board controls the trigger switch according to the submodule voltage, and realizes the switching between the high-voltage power supply and the low-voltage power supply and the submodule through the trigger switch.

[0012] Furthermore, the operating voltage range of the low voltage power supply is 24V-350V.

[0013] Furthermore, the low-voltage power supply and the high-voltage power supply both adopt a DC / DC circuit structure.

[0014] The beneficial effects of the present invention are as follows: as an improved invention, the present invention realizes real-time monitoring of the voltage value of the submodule by using the SCE control board during the process of the converter valve submodule discharging the voltage by setting a low-voltage power supply. When the voltage value of the submodule drops to the set voltage, the SCE control board controls the low-voltage power supply access circuit to continue to power the SCE control board, and at the same time disconnects the high-voltage power supply that can no longer output voltage, ensuring that the SCE control board can still be powered normally when the voltage value of the submodule is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Schematic diagram of the novel flexible DC converter valve submodule power supply device for charging the multi-stage power supply of the present invention. DETAILED DESCRIPTION

[0016] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0017] The present invention provides a submodule that continues to supply power to the SCE module after the submodule voltage value is lower than the set voltage, thereby achieving continued power supply to the SCE control board after the submodule voltage value is lower than the critical voltage of the high-voltage power supply.

[0018] Implementation Method of Flexible Direct Current Converter Valve The present invention proposes a new type of flexible direct current valve. Figure 1 As shown, the device includes an SCE control board, a GDU driver board, a bypass switch and thyristor trigger, a high-voltage power supply, and a low-voltage power supply. The SCE control board primarily monitors the submodule voltage in real time and switches the power supply when the voltage reaches the set voltage. Furthermore, the SCE control board controls the bypass switch K2 and transistor TR1 in the submodule circuit via the bypass switch and thyristor trigger. The GDU driver board primarily controls the first IGBT T1 and second IGBT T2 in the submodule circuit according to instructions from the SCE control board. Both the high-voltage power supply and the low-voltage power supply are energy-drawing power sources. Both the high-voltage power supply and the low-voltage power supply are connected to the SCE control board and the GDU driver board. The high-voltage power supply operates when the submodule voltage exceeds the set voltage, converting the current submodule voltage into the operating voltage for the SCE control board and the GDU driver board. The low-voltage power supply operates when the submodule voltage is below the set voltage but above the safety voltage, converting the current submodule voltage into the operating voltage for the SCE control board and the GDU driver board.

[0019] Specifically, during the power-on process, since the voltage value in the submodule circuit is low at this time, the low-voltage power supply is used by default to power the SCE control board and the GDU driver board. The low-voltage power supply is connected to both sides of the charging capacitor by triggering the switch K1. The low-voltage power supply converts the electric energy released by the charging capacitor and powers the SCE control board. The SCE control board also starts to monitor the voltage of the submodule circuit in real time. When the voltage value in the submodule circuit continues to rise to the set voltage value of the voltage, the SCE control board sends a trigger switch switching signal, triggering the switch K1 to disconnect from the low-voltage power supply, and connect the high-voltage power supply to the circuit for power supply. As an embodiment, the set voltage value of the set voltage is 350V, which is the lowest operating voltage for the high-voltage power supply to perform voltage conversion.

[0020] During voltage discharge, the high-voltage power supply is used, and the SCE control board monitors the voltage in the submodule circuit in real time. When the submodule voltage drops to a set voltage, the SCE control board sends a trigger switch switching signal, controlling trigger switch K1 to disconnect the high-voltage power supply and connect the low-voltage power supply to the circuit. Using trigger switch K1 to connect either the high-voltage or low-voltage power supply ensures that only one power supply is connected to the circuit at a time, ensuring power supply safety. Furthermore, when the voltage drops below the set voltage, the SCE control board can continue to monitor the submodule's discharge voltage while operating from the low-voltage power supply. This eliminates the need for operators to connect the SCE control board to an external low-voltage power supply or monitor the submodule's discharge voltage using a multimeter, reducing the risk of electric shock and improving safety. As an example, the SCE control board can monitor the submodule's discharge voltage within a range of 24-350V while operating from a low-voltage power supply. 24V is set as the minimum value in the range because voltages below 24V are considered safe for humans and no longer require real-time monitoring.

[0021] In summary, the present invention adopts a multi-stage power supply method to power the SCE control board, which enables the SCE control board to effectively obtain the latest and real-time module status information so as to upload it to the main control end in a timely, accurate and efficient manner. When low-voltage pressurization operation is required, it can be powered by a low-voltage power supply, thereby enhancing the scalability of the power supply of the flexible direct current valve sub-module, saving time, and expanding the monitoring range of the sub-module voltage, effectively reducing the risk of electric shock, and having low cost, low energy consumption, long life, and green environmental protection.

[0022] Implementation method of full voltage power supply device for flexible DC converter valve submodule The present invention proposes a full-voltage power supply device for submodules of a flexible direct current converter valve, comprising a submodule circuit, an SCE control board, a GDU drive board and a high-voltage power supply. In order to continue to power the SCE control board and the GDU drive board by converting the submodule voltage when the submodule voltage is lower than the minimum operating voltage of the high-voltage power supply for voltage conversion, the converter valve also includes a low-voltage power supply. The low-voltage power supply is used to operate when the submodule voltage is lower than the set voltage value and higher than the safety voltage, and convert the current submodule voltage into the operating voltage of the SCE control board and the GDU drive board.

[0023] In order to ensure that only one set of circuits is connected to the access circuit for power supply during power supply, a trigger switch is also provided in the flexible DC converter valve. The trigger switch is used to switch the high-voltage power supply or low-voltage power supply to the sub-module according to the sub-module voltage under the control of the SCE control board, and convert the current sub-module voltage into the operating voltage of the SCE control board and the GDU driver board.

[0024] The specific implementation process has been described in detail in the flexible DC converter valve implementation method and will not be repeated here.

Claims

1. A full voltage power supply device for a flexible DC converter valve submodule, characterized in that: The device includes a high-voltage power supply and a low-voltage power supply, both of which are used to supply power to the SCE control board and the GDU driver board. Both the high-voltage power supply and the low-voltage power supply are energy-taking power supplies, both of which take energy from the sub-module. The low-voltage power supply is used to work when the sub-module voltage is lower than the set voltage value and higher than the safety voltage, and convert the current sub-module voltage into the operating voltage of the SCE control board and the GDU driver board. The high-voltage power supply is used to work when the sub-module voltage is higher than the set voltage value, and convert the current sub-module voltage into the operating voltage of the SCE control board and the GDU driver board.

2. The full-voltage power supply device for flexible DC converter valve submodule according to claim 1, characterized in that: The set voltage value is the lowest operating voltage of the high voltage power supply for voltage conversion.

3. The full-voltage power supply device for the flexible DC converter valve submodule according to claim 2, characterized in that: It also includes a trigger switch for switching the high-voltage power supply or low-voltage power supply to connect to the submodule according to the submodule voltage under the control of the SCE control board, and converting the current submodule voltage into the operating voltage of the SCE control board and the GDU driver board.

4. The full-voltage power supply device for flexible DC converter valve submodule according to claim 1, characterized in that: The low-voltage power supply and the high-voltage power supply both adopt a DC / DC circuit structure.

5. A flexible direct current converter valve, comprising a submodule circuit, an SCE control board, a GDU drive board and a high-voltage power supply, characterized in that: It also includes a low-voltage power supply. Both the high-voltage power supply and the low-voltage power supply are used to power the SCE control board and the GDU driver board. Both the high-voltage power supply and the low-voltage power supply are energy-taking power supplies, and both take energy from the sub-module. The low-voltage power supply is used to work when the sub-module voltage is lower than the set voltage value and higher than the safety voltage, and converts the current sub-module voltage into the working voltage of the SCE control board and the GDU driver board. The high-voltage power supply is used to work when the sub-module voltage is higher than the set voltage value, and converts the current module voltage into the working voltage of the SCE control board and the GDU driver board.

6. The flexible direct current converter valve according to claim 5, characterized in that: The set voltage value is the minimum operating voltage for high voltage power conversion.

7. The flexible direct current converter valve according to claim 6, characterized in that: It also includes a trigger switch. The SCE control board controls the trigger switch according to the sub-module voltage, and realizes the switching between the high-voltage power supply and the low-voltage power supply and the sub-module through the trigger switch.

8. The flexible direct current converter valve according to claim 5, characterized in that: The low voltage power supply operates in the voltage range of 24V-350V.

9. The flexible direct current converter valve according to claim 5, characterized in that: The low-voltage power supply and the high-voltage power supply both adopt a DC / DC circuit structure.

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