An ultra-high voltage flexible direct current valve group connection line voltage measurement anomaly detection and switching method

Abstract

The application discloses a kind of UHV flexible valve group connecting line voltage measurement abnormality detection and switching method, comprising, obtaining control device valve group connecting line voltage measurement value UDM, redundancy device valve group connecting line voltage measurement value UDM_OSYS and abnormality detection auxiliary judgment value UV, obtain the intermediate size value UMID in three;When the difference between UDM and UMID is greater than the first reference value UREF1, and lasts the first delay time T1ref, it is considered that control device valve group connecting line voltage measurement value UDM is abnormal;Redundancy device valve group connecting line voltage measurement value UDM_OSYS or the connecting line voltage value UDMCAL calculated based on the measured electrical quantity of control device is used as the connecting line voltage measurement value UDM0 of control device.The application detects redundancy device valve group connecting line voltage measurement value and abnormality detection auxiliary judgment value to realize the detection of control device valve group connecting line measurement value abnormality, and switches to correct value, maintains system stable operation, principle is reliable, and realization is simple.

Description

A method for detecting and switching abnormal voltage measurements in ultra-high voltage flexible direct current valve group connection lines. Technical Field

[0001] This invention belongs to the field of flexible DC power systems, specifically relating to a method for detecting and switching abnormal voltage measurements on the connecting lines of ultra-high voltage flexible DC valve groups. Background Technology

[0002] Ultra-high voltage flexible direct current transmission systems (MMC-UHVDC) exhibit significant technological advantages in large-scale centralized transmission of renewable energy due to their long-distance, high-capacity transmission capabilities, DC line characteristics without charging power limitations, and ability to decouple from the AC grid. This system is particularly suitable for constructing multi-energy complementary renewable energy DC grids and will play a crucial role in the construction of future new power systems.

[0003] However, due to the high voltage level and large capacity characteristics of UHV flexible DC transmission systems, single voltage source converter valve group schemes present significant challenges in equipment manufacturing and transportation. Specifically, the size and weight of a single voltage source converter valve group make it difficult to meet practical engineering requirements. In contrast, a series connection scheme using multiple voltage source converter valve groups can effectively solve these problems, making equipment manufacturing and transportation more feasible. Therefore, current UHV flexible DC transmission systems generally adopt a series connection voltage source converter valve group design.

[0004] In the control system of a series voltage source converter valve group, accurate acquisition of the connection line voltage is required to achieve constant voltage control or voltage equalization control of the high-end and low-end valve groups. However, existing measurement methods are insufficient in dealing with abnormal valve group connection line voltages, which may lead to system instability. To ensure the reliability and stability of the system, it is essential to detect and switch to the correct voltage value in a timely manner. Therefore, there is an urgent need to develop an effective method for detecting and switching abnormal valve group connection line voltage measurements to ensure stable system operation. Summary of the Invention

[0005] The purpose of this invention is to provide a method for detecting and switching abnormal voltage measurements in the connection lines of ultra-high voltage flexible DC valve groups. This method detects abnormal voltage measurements in the connection lines of the control device valve group by detecting the voltage measurements of the redundant device valve group and the auxiliary judgment value for abnormal detection, and switches to the correct value to maintain stable system operation. The principle is reliable and the implementation is simple.

[0006] To achieve the above objectives, the solution of the present invention is:

[0007] A method for detecting and switching abnormal voltage measurements on the connection line of an ultra-high voltage flexible direct current valve group includes,

[0008] Acquire the measured voltage values ​​of the control device valve group connection line UDM, the measured voltage values ​​of the redundant device valve group connection line UDM_OSYS, and the anomaly detection auxiliary judgment value UV;

[0009] Compare the measured values ​​of the valve assembly connection line voltage UDM, the redundant device valve assembly connection line voltage UDM_OSYS, and the anomaly detection auxiliary judgment value UV, and obtain the median value UMID among the three.

[0010] When the difference between the measured voltage UDM of the valve group connection line of the control device and the intermediate value UMID is greater than the first reference value UREF1 and continues for the first delay time T1ref, the measured voltage UDM of the valve group connection line of the control device is considered abnormal.

[0011] When the measured value UDM of the valve group connection line voltage of the control device is abnormal, the measured value UDM_OSYS of the redundant device valve group connection line voltage or the connection line voltage value UDMCAL calculated based on the measured electrical quantity of the control device shall be used as the measured value UDM0 of the control device connection line voltage.

[0012] Among them, obtaining the anomaly detection auxiliary judgment value (UV) includes,

[0013] The abnormality detection auxiliary judgment value UV is obtained by calculation, or the valve group connection line voltage measurement value is obtained by a second redundant device and used as the abnormality detection auxiliary judgment value UV.

[0014] The anomaly detection auxiliary judgment value UV, obtained through calculation, includes:

[0015] The pole line voltage value UDL and the neutral line voltage value UDN of the UHV flexible DC transmission system are obtained, and the anomaly detection auxiliary judgment value UV is calculated according to UV=(UDL+UDN) / 2.

[0016] Among them, obtaining the median value UMID of the three includes,

[0017] If UDM > UDM_OSYS > UV or UV > UDM_OSYS > UDM, then UMID = UDM_OSYS;

[0018] If UDM_OSYS > UDM > UV or UV > UDM > UDM_OSYS, then UMID = UDM;

[0019] If UDM_OSYS > UV > UDM or UDM > UV > UDM_OSYS, then UMID = UV.

[0020] Specifically, if the difference between the measured voltage UDM of the control device valve group connection line and the intermediate value UMID is greater than the first reference value UREF1, and this difference persists for a first delay time T1ref, the measured voltage UDM of the control device valve group connection line is considered abnormal, including:

[0021] Obtain the difference between the measured voltage value UDM of the valve group connection line of the control device and the intermediate value UMID, which is UDM_ER.

[0022] When the difference UDM_ER is greater than the first reference value UREF1, the timing variable T1 starts timing until the timing variable T1 = the first delay time T1ref, and the difference UDM_ER is always greater than the first reference value UREF1. Then, the voltage measurement value UDM of the valve group connection line of the control device is considered abnormal.

[0023] When the timing variable T1 starts timing, if the difference UDM_ER is less than UREF1-ZHIHUAN, the timing variable T1 is cleared to zero, and ZHIHUAN is the hysteresis setpoint.

[0024] The determination that the measured voltage UDM of the valve assembly connection line of the control device is abnormal also includes setting the abnormal state signal high and maintaining it for a second delay time T2ref.

[0025] When the timing variable T1 is greater than the first delay time T1ref, the abnormal state signal PL is set to high level, and the timer T2 starts timing.

[0026] When the timing variable T1 is less than or equal to the first delay time T1ref, if the abnormal status signal PL is low, then the abnormal status signal PL remains low; if the abnormal status signal PL is high and T2≤T2ref, then the abnormal status signal PL remains low; if PL is high and T2>T2ref, then PL is set to low and the timer T2 is cleared.

[0027] The connection line voltage value UDMCAL, calculated based on electrical quantities measured by the control device, includes:

[0028] Acquire electrical quantities measured by the control device, including pole line voltage value UDL, three-phase valve side voltage values ​​UVCA, UVCB, and UVCC;

[0029] The connection line voltage value UDMCAL is calculated based on the type of control device.

[0030] If the control device is a high-end valve assembly, then,

[0031]

[0032] If the control device is a low-end valve group device, then,

[0033]

[0034] UDN is the neutral line voltage value.

[0035] The connection line voltage value UDMCAL, calculated based on electrical quantities measured by the control device, includes:

[0036] Acquire electrical quantities measured by the control device, including pole line voltage UDL, three-phase submodule voltages UA_SUM, UB_SUM, and UC_SUM;

[0037] The connection line voltage value UDMCAL is calculated based on the type of control device.

[0038] If the control device is a high-end valve assembly, then,

[0039]

[0040] If the control device is a low-end valve group device, then,

[0041]

[0042] UDN is the neutral line voltage value.

[0043] A system for detecting and switching abnormal voltage measurements on the connection line of an ultra-high voltage flexible direct current valve group includes,

[0044] The data acquisition module is configured to acquire the measured voltage value UDM of the valve group connection line of the control device, the measured voltage value UDM_OSYS of the valve group connection line of the redundant device, and the abnormal detection auxiliary judgment value UV.

[0045] The intermediate value acquisition module is configured to compare the valve group connection line voltage measurement value UDM, the redundant device valve group connection line voltage measurement value UDM_OSYS, and the anomaly detection auxiliary judgment value UV, and obtain the median value UMID among the three.

[0046] The abnormal state judgment module is configured to consider the measured voltage UDM of the control device valve group connection line to be abnormal when the difference between the measured voltage UDM and the intermediate value UMID is greater than the first reference value UREF1 and continues for a first delay time T1ref; and,

[0047] The measurement value setting module is configured to, when the abnormal state judgment module considers the control device valve group connection line voltage measurement value UDM to be abnormal, use the redundant device valve group connection line voltage measurement value UDM_OSYS or the connection line voltage value UDMCAL calculated based on the electrical quantity measured by the control device as the control device connection line voltage measurement value UDM0.

[0048] The data acquisition module acquires the anomaly detection auxiliary judgment value (UV), including:

[0049] The abnormality detection auxiliary judgment value UV is obtained by calculation, or the valve group connection line voltage measurement value is obtained by a second redundant device and used as the abnormality detection auxiliary judgment value UV.

[0050] The anomaly detection auxiliary judgment value UV, obtained through calculation, includes:

[0051] The pole line voltage value UDL and the neutral line voltage value UDN of the UHV flexible DC transmission system are obtained, and the anomaly detection auxiliary judgment value UV is calculated according to UV=(UDL+UDN) / 2.

[0052] The intermediate value acquisition module obtains the median value UMID among the three, including:

[0053] If UDM > UDM_OSYS > UV or UV > UDM_OSYS > UDM, then UMID = UDM_OSYS;

[0054] If UDM_OSYS > UDM > UV or UV > UDM > UDM_OSYS, then UMID = UDM;

[0055] If UDM_OSYS > UV > UDM or UDM > UV > UDM_OSYS, then UMID = UV.

[0056] Specifically, if the difference between the measured voltage UDM of the control device valve group connection line and the intermediate value UMID is greater than the first reference value UREF1, and this difference persists for a first delay time T1ref, the measured voltage UDM of the control device valve group connection line is considered abnormal, including:

[0057] Obtain the difference between the measured voltage value UDM of the valve group connection line of the control device and the intermediate value UMID, which is UDM_ER.

[0058] When the difference UDM_ER is greater than the first reference value UREF1, the timing variable T1 starts timing until the timing variable T1 = the first delay time T1ref, and the difference UDM_ER is always greater than the first reference value UREF1. Then, the voltage measurement value UDM of the valve group connection line of the control device is considered abnormal.

[0059] When the timing variable T1 starts timing, if the difference UDM_ER is less than UREF1-ZHIHUAN, the timing variable T1 is cleared to zero, and ZHIHUAN is the hysteresis setpoint.

[0060] Specifically, when the abnormal state judgment module determines that the measured value of the valve group connection line voltage UDM of the control device is abnormal, the abnormal state judgment module sets the abnormal state signal to a high level and continues it for a second delay time T2ref, including:

[0061] When the timing variable T1 is greater than the first delay time T1ref, the abnormal state signal PL is set to high level, and the timer T2 starts timing.

[0062] When the timing variable T1 is less than or equal to the first delay time T1ref, if the abnormal status signal PL is low, then the abnormal status signal PL remains low; if the abnormal status signal PL is high and T2≤T2ref, then the abnormal status signal PL remains low; if PL is high and T2>T2ref, then PL is set to low and the timer T2 is cleared.

[0063] The measurement value setting module calculates the connection line voltage value UDMCAL based on the electrical quantities measured by the control device, including:

[0064] Acquire electrical quantities measured by the control device, including pole line voltage value UDL, three-phase valve side voltage values ​​UVCA, UVCB, and UVCC;

[0065] The connection line voltage value UDMCAL is calculated based on the type of control device.

[0066] If the control device is a high-end valve assembly, then,

[0067]

[0068] If the control device is a low-end valve group device, then,

[0069]

[0070] UDN is the neutral line voltage value.

[0071] The measurement value setting module calculates the connection line voltage value UDMCAL based on the electrical quantities measured by the control device, including:

[0072] Acquire electrical quantities measured by the control device, including pole line voltage UDL, three-phase submodule voltages UA_SUM, UB_SUM, and UC_SUM;

[0073] The connection line voltage value UDMCAL is calculated based on the type of control device.

[0074] If the control device is a high-end valve assembly, then,

[0075]

[0076] If the control device is a low-end valve group device, then,

[0077]

[0078] UDN is the neutral line voltage value.

[0079] A computer device includes a memory, a processor, and a computer program stored in the memory and executable on the processor; when the processor executes the computer program, it implements the steps of the above-described method for detecting and switching abnormal voltage measurements of UHV flexible direct current valve group connection lines.

[0080] A computer-readable storage medium storing a computer program; when executed by a processor, the computer program implements the steps of the above-described method for detecting and switching abnormal voltage measurements of UHV flexible direct current valve group connection lines.

[0081] After adopting the above solution, this invention analyzes the existing technology, which only judges whether the voltage at the measurement point is abnormal based on the communication status flag. However, voltage measurement is not just a communication issue; there are also cases where the voltage deviates abnormally small or large from the actual value, in which case the communication flag is still good. Therefore, the existing technology, which judges whether the voltage measurement point is abnormal solely based on the communication status, is insufficient to detect such abnormal voltage deviations from the actual value.

[0082] Therefore, this invention integrates the measured voltage values ​​of the valve group connection lines of the device, the measured voltage values ​​of the valve group connection lines of the redundant devices, and the auxiliary judgment value for anomaly detection for judgment. Specifically, utilizing the measured voltage values ​​of the valve group connection lines of the redundant devices fully utilizes the control and protection redundancy devices of the flexible DC system, eliminating the need for additional voltage monitoring devices and saving costs. Utilizing the auxiliary judgment value for anomaly detection avoids misjudgments of measurement anomalies in the redundant system's own measurement anomalies. It fully utilizes other redundant devices when multiple redundancies are used, or, when no additional redundancy is available, uses calculated theoretical connection line voltage measurements to determine measurement anomalies. This invention can avoid misjudgments of the valve group connection line measurements of the control device when there are measurement anomalies in redundant devices or when the auxiliary judgment value for anomaly detection is abnormal. It is reliable in principle, simple to implement, and maintains the stable operation of the UHV flexible DC system. Attached Figure Description

[0083] Figure 1 is a flowchart of the method of the present invention;

[0084] Figure 2 is a schematic diagram of the key measuring points in this invention. Detailed Implementation

[0085] This invention provides a method for detecting and switching abnormal voltage measurements on the connection lines of ultra-high voltage flexible direct current valve groups, including:

[0086] Acquire the measured voltage values ​​of the control device valve group connection line UDM, the measured voltage values ​​of the redundant device valve group connection line UDM_OSYS, and the anomaly detection auxiliary judgment value UV;

[0087] Compare the measured values ​​of the valve assembly connection line voltage UDM, the redundant device valve assembly connection line voltage UDM_OSYS, and the anomaly detection auxiliary judgment value UV, and obtain the median value UMID among the three.

[0088] When the difference between the measured voltage UDM of the valve group connection line of the control device and the intermediate value UMID is greater than the first reference value UREF1 and continues for the first delay time T1ref, the measured voltage UDM of the valve group connection line of the control device is considered abnormal.

[0089] When the measured value UDM of the valve group connection line voltage of the control device is abnormal, the measured value UDM_OSYS of the redundant device valve group connection line voltage or the connection line voltage value UDMCAL calculated based on the measured electrical quantity of the control device shall be used as the measured value UDM0 of the control device connection line voltage.

[0090] Among them, obtaining the anomaly detection auxiliary judgment value (UV) includes,

[0091] The abnormality detection auxiliary judgment value UV is obtained by calculation, or the valve group connection line voltage measurement value is obtained by a second redundant device and used as the abnormality detection auxiliary judgment value UV.

[0092] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0093] During normal operation, ultra-high voltage flexible DC dual-valve manifolds require precise acquisition of the valve manifold connection line voltage to achieve constant voltage control or voltage equalization control for the high-end and low-end valve groups. However, when the valve manifold connection line voltage UDM is abnormal, the control device will also malfunction, leading to DC system lockout. Therefore, it is necessary to promptly detect abnormal valve manifold connection line voltage measurements and switch to the correct value in a timely manner to ensure the reliability and stability of the system.

[0094] In view of this, this invention provides a method for detecting and switching abnormal voltage measurements on the connection line of an ultra-high voltage flexible direct current valve group. As shown in Figure 1, the method includes:

[0095] Step 101: Initialize timers T1 and T2 to 0, and initialize the status signal PL to low level;

[0096] Step 102: Obtain the electrical quantity sampling values ​​of this device and the redundant device. In this embodiment, the parameters selected include the measured value of the connection line voltage of this device UDM, the measured values ​​of the valve group connection line voltage of the redundant device UDM_OSYS and UDM_OSYSC, the measured value of the pole line voltage UDL, the measured value of the neutral line voltage UDN, and the valve side voltage UVC.

[0097] To obtain the anomaly detection auxiliary judgment value UV, you can choose UV = UDM_OSYSC or UV = (UDL + UDN) / 2;

[0098] Get the median value UMID among UDM, UDM_OSYS, and UV;

[0099] Step 103: If the difference between the measured value UDM of the valve group connection line voltage of this device and the intermediate value UMD is greater than the first reference value UREF1 and lasts for the first delay time T1ref, then the measured value of the valve group connection line voltage of this device is considered abnormal, the abnormal status signal is set to high level, and this abnormal status signal lasts for the second delay time T2ref.

[0100] Step 104: After detecting a measurement anomaly, set the measured line voltage UDM0 of this device to the measured value UDM_OSYS of the redundant device or the measured line voltage UDMAL calculated based on the electrical quantities of this device.

[0101] In some embodiments, this device is a control device, and the redundant device is a backup system with the same function as this control device. The redundant device is connected to a redundant measuring device, and the measuring device connected to this control device and the measuring device connected to the redundant device are independent of each other.

[0102] In some embodiments, the anomaly detection auxiliary judgment value UV is the valve group connection line voltage measurement value obtained by calculation or a third set of redundant devices.

[0103] Specifically, referring to Figure 2, the pole line voltage value UDL and neutral line voltage value UDN of the UHV flexible DC transmission system (flexible DC system) are obtained, then UV = (UDL + UDN) / 2.

[0104] Specifically, the third set of redundant devices is the third set of protection devices, which is connected to the third set of measuring devices. The two sets of measuring devices connected to the third set of measuring devices and the control device are independent of each other.

[0105] In some embodiments, the method for obtaining the median value UMID among UDM, UDM_OSYS, and UV is as follows:

[0106] If UDM > UDM_OSYS > UV or UDM > UDM_OSYS > UV, then UMID = UDM_OSYS;

[0107] If UDM_OSYS > UDM > UV or UV > UDM > UDM_OSYS, then UMID = UDM;

[0108] If UDM_OSYS > UV > UDM or UDM > UV > UDM_OSYS, then UMID = UV.

[0109] In some embodiments, the specific implementation method for step 103, which states that if the difference between the measured value UDM and the intermediate value UMD of the valve group connection line voltage of this device is greater than the first reference value UREF1 and continues for a first delay time T1ref, then the measured value of the valve group connection line voltage of this device is considered abnormal, is as follows:

[0110] Step 1031, the difference between UDM and the intermediate size value UMID is: UDM_ER = |UDM - UMID|;

[0111] The method for determining the first delay time T1ref is as follows: Define a timing variable T1. When UDM_ER is greater than UREF1, timing variable T1 starts timing; when UDM_ER is less than UREF1-ZHIHUAN, timing variable T1 is cleared to zero, and ZHIHUAN is the hysteresis setpoint.

[0112] The method for determining abnormal voltage measurement values ​​of the valve group connection lines in this device is as follows: Define an abnormal state signal PL. When T1 > T1ref, the voltage measurement values ​​of the valve group connection lines in this device are abnormal, and PL is set to a high level.

[0113] Step 1032, the method for maintaining the abnormal state signal for a second delay time is as follows:

[0114] Define a timer T2;

[0115] When T1 is greater than T1ref, PL is set to high level, then cleared to zero and the timer starts.

[0116] When T1 is less than or equal to T1ref, if PL is low, then PL remains low; if PL is high and T2 ≤ T2ref, then PL remains low, i.e., it maintains its original state; if PL is high and T2 > T2ref, then PL is set low and timer T2 is cleared.

[0117] In some embodiments, a method for calculating the valve group connection line voltage based on the pole line voltage UDL, valve side voltage UVC (UVCA, UVCB, UVCC), and neutral point voltage UDN, derived from the connection line voltage value UDMCAL calculated by the electrical quantities of this device, is as follows:

[0118] If this device is a high-end valve assembly, then:

[0119]

[0120] If this device is a low-end valve assembly device, then:

[0121]

[0122] In some embodiments, a method for calculating the valve group connection line voltage based on the connection line voltage value UDMCAL calculated from the electrical quantities of this device, using the pole line voltage, submodule voltage U_SUM (submodule voltages of the upper and lower bridge arms of phase A and UA_SUM, voltages of the upper and lower bridge arms of phase B and UB_SUM, voltages of the upper and lower bridge arms of phase C and UC_SUM), and neutral point voltage, is as follows:

[0123] If this device is a high-end valve assembly, then:

[0124]

[0125] If this device is a low-end valve assembly device, then:

[0126]

[0127] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0128] This invention also provides a system for detecting and switching abnormal voltage measurements on the connection line of an ultra-high voltage flexible direct current valve group, comprising:

[0129] The data acquisition module is configured to acquire the measured voltage value UDM of the valve group connection line of the control device, the measured voltage value UDM_OSYS of the valve group connection line of the redundant device, and the abnormal detection auxiliary judgment value UV.

[0130] The intermediate value acquisition module is configured to compare the valve group connection line voltage measurement value UDM, the redundant device valve group connection line voltage measurement value UDM_OSYS, and the anomaly detection auxiliary judgment value UV, and obtain the median value UMID among the three.

[0131] The abnormal state judgment module is configured to consider the measured voltage UDM of the control device valve group connection line to be abnormal when the difference between the measured voltage UDM and the intermediate value UMID is greater than the first reference value UREF1 and continues for a first delay time T1ref; and to set the abnormal state signal high for a second delay time T2ref; and,

[0132] The measurement value setting module is configured to use the redundant device valve group connection line voltage measurement value UDM_OSYS or the connection line voltage value UDMCAL calculated based on the electrical quantity measured by the control device as the connection line voltage measurement value UDM0 of the control device.

[0133] The data acquisition module acquires the anomaly detection auxiliary judgment value (UV), including:

[0134] The abnormality detection auxiliary judgment value UV is obtained by calculation, or the valve group connection line voltage measurement value is obtained by a second redundant device and used as the abnormality detection auxiliary judgment value UV.

[0135] The anomaly detection auxiliary judgment value UV, obtained through calculation, includes:

[0136] The pole line voltage value UDL and the neutral line voltage value UDN of the UHV flexible DC transmission system are obtained, and the anomaly detection auxiliary judgment value UV is calculated according to UV=(UDL+UDN) / 2.

[0137] The intermediate value acquisition module obtains the median value UMID among the three, including:

[0138] If UDM > UDM_OSYS > UV or UV > UDM_OSYS > UDM, then UMID = UDM_OSYS;

[0139] If UDM_OSYS > UDM > UV or UV > UDM > UDM_OSYS, then UMID = UDM;

[0140] If UDM_OSYS > UV > UDM or UDM > UV > UDM_OSYS, then UMID = UV.

[0141] Specifically, if the difference between the measured voltage UDM of the control device valve group connection line and the intermediate value UMID is greater than the first reference value UREF1, and this difference persists for a first delay time T1ref, the measured voltage UDM of the control device valve group connection line is considered abnormal, including:

[0142] Obtain the difference between the measured voltage value UDM of the valve group connection line of the control device and the intermediate value UMID, which is UDM_ER.

[0143] When the difference UDM_ER is greater than the first reference value UREF1, the timing variable T1 starts timing. When the timing variable T1 equals the first delay time T1ref, if the difference UDM_ER is always greater than the first reference value UREF1, then the voltage measurement value UDM of the valve group connection line of the control device is considered abnormal.

[0144] When the timing variable T1 starts timing, if the difference UDM_ER is less than UREF1-ZHIHUAN, the timing variable T1 is cleared to zero, and ZHIHUAN is the hysteresis setpoint.

[0145] The abnormal state judgment module sets the abnormal state signal to a high level and maintains it for a second delay time T2ref, including:

[0146] When the timing variable T1 is greater than the first delay time T1ref, the abnormal state signal PL is set to high level, and the timer T2 starts timing.

[0147] When the timing variable T1 is less than or equal to the first delay time T1ref, if the abnormal status signal PL is low, then the abnormal status signal PL remains low; if the abnormal status signal PL is high and T2≤T2ref, then the abnormal status signal PL remains low; if PL is high and T2>T2ref, then PL is set to low and the timer T2 is cleared.

[0148] The measurement value setting module calculates the connection line voltage value UDMCAL based on the electrical quantities measured by the control device, including:

[0149] Acquire electrical quantities measured by the control device, including pole line voltage UDL, three-phase valve side voltages UVCA, UVCB, and UVCC;

[0150] The connection line voltage value UDMCAL is calculated based on the type of control device.

[0151] If the control device is a high-end valve assembly, then,

[0152]

[0153] If the control device is a low-end valve group device, then,

[0154]

[0155] The measurement value setting module calculates the connection line voltage value UDMCAL based on the electrical quantities measured by the control device, including:

[0156] Acquire electrical quantities measured by the control device, including pole line voltage UDL, three-phase submodule voltages UA_SUM, UB_SUM, and UC_SUM;

[0157] The connection line voltage value UDMCAL is calculated based on the type of control device.

[0158] If the control device is a high-end valve assembly, then,

[0159]

[0160] If the control device is a low-end valve group device, then,

[0161]

[0162] This invention also provides another computer device, including a processor and a memory configured to store a computer program capable of running on the processor; wherein, when the processor is configured to run the computer program, it performs the method steps described in the foregoing embodiments.

[0163] In practical applications, the aforementioned processor includes a Field-Programmable Gate Array (FPGA), and the processor can be a Central Processing Unit (CPU) or a Digital Signal Processor (DSP). It is understood that for different devices, the electronic devices used to implement the functions of the aforementioned processor can also be other types, and this embodiment of the invention does not impose specific limitations.

[0164] The aforementioned memory can be volatile memory, such as random-access memory (RAM); or non-volatile memory, such as read-only memory (ROM), flash memory, hard disk drive (HDD), or solid-state drive (SSD); or a combination of the above types of memory, and provides instructions and data to the processor.

[0165] In an exemplary embodiment, the present invention also provides a computer-readable storage medium for storing a computer program.

[0166] Optionally, the computer-readable storage medium can be applied to any of the methods in the embodiments of the present invention, and the computer program causes the computer to execute the corresponding processes implemented by the processor in the various methods of the embodiments of the present invention. For the sake of brevity, these will not be described in detail here.

[0167] In the several embodiments provided by this invention, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods, such as: multiple units or components can be combined, or integrated into another system, or some features can be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the various components shown or discussed can be through some interfaces, and the indirect coupling or communication connection between devices or units can be electrical, mechanical, or other forms.

[0168] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. The solutions in the embodiments of the present invention can be implemented using various computer languages, such as the object-oriented programming language Java and the interpreted scripting language JavaScript.

[0169] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in one or more blocks of the flowchart illustrations and / or one or more blocks of the block diagrams.

[0170] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means that implement the functions specified in one or more flowcharts and / or one or more block diagrams.

[0171] These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, such that the instructions, which execute on the computer or other programmable apparatus, provide steps for implementing the functions specified in one or more flowcharts and / or one or more block diagrams.

[0172] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0173] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for detecting and switching abnormal voltage measurements on the connection line of an ultra-high voltage flexible direct current valve group, characterized in that: This includes acquiring the measured voltage value UDM of the control device valve group connection line, the measured voltage value UDM_OSYS of the redundant device valve group connection line, and the anomaly detection auxiliary judgment value UV; comparing the magnitudes of the measured voltage value UDM, the measured voltage value UDM_OSYS of the redundant device valve group connection line, and the anomaly detection auxiliary judgment value UV, and obtaining the median value UMID among the three; when the difference between the measured voltage value UDM of the control device valve group connection line and the median value UMID is greater than the first reference value UREF1, and continues for a first delay time T1ref, the measured voltage value UDM of the control device valve group connection line is considered abnormal; when the measured voltage value UDM of the control device valve group connection line is abnormal, the measured voltage value UDM_OSYS of the redundant device valve group connection line or the connection line voltage value UDMCAL calculated based on the measured electrical quantities of the control device is used as the connection line voltage of the control device. The measured value is UDM0; wherein, obtaining the anomaly detection auxiliary judgment value UV includes, either by calculating the anomaly detection auxiliary judgment value UV, or by obtaining the valve group connection line voltage measurement value through a separately set second redundant device, as the anomaly detection auxiliary judgment value UV; wherein, obtaining the anomaly detection auxiliary judgment value UV by calculation includes, obtaining the UHV flexible DC transmission system pole line voltage value UDL and neutral line voltage value UDN, and calculating the anomaly detection auxiliary judgment value UV according to UV=(UDL+UDN) / 2; wherein, calculating the connection line voltage value UDMCAL based on the electrical quantities measured by the control device includes, obtaining the electrical quantities measured by the control device, including the pole line voltage value UDL, the three-phase valve side voltage values ​​UVCA, UVCB, and UVCC; calculating the connection line voltage value UDMCAL according to the type of control device; wherein, if the control device is a high-end valve group device, then, If the control device is a low-end valve group device, then... Wherein, UDN is the neutral line voltage value; or, the connection line voltage value UDMCAL is calculated based on the electrical quantities measured by the control device, including acquiring the electrical quantities measured by the control device, including the pole line voltage value UDL, the three-phase submodule voltages UA_SUM, UB_SUM, and UC_SUM; and calculating the connection line voltage value UDMCAL according to the type of control device; wherein, if the control device is a high-side valve group device, then... If the control device is a low-end valve group device, then, Where UDN is the neutral line voltage value.

2. The method as described in claim 1, characterized in that: The middle value UMID among the three is obtained as follows: if UDM > UDM_OSYS > UV or UV > UDM_OSYS > UDM, then UMID = UDM_OSYS; if UDM_OSYS > UDM > UV or UV > UDM > UDM_OSYS, then UMID = UDM; if UDM_OSYS > UV > UDM or UDM > UV > UDM_OSYS, then UMID = UV.

3. The method as described in claim 1, characterized in that: If the difference between the measured voltage UDM of the valve group connection line of the control device and the intermediate value UMID is greater than the first reference value UREF1, and this difference persists for a first delay time T1ref, the measured voltage UDM of the valve group connection line of the control device is considered abnormal. This includes obtaining the difference UDM_ER between the measured voltage UDM of the valve group connection line of the control device and the intermediate value UMID; when the difference UDM_ER is greater than the first reference value UREF1, the timing variable T1 starts timing until the timing variable T1 equals the first delay time T1ref, and the difference UDM_ER is always greater than the first reference value UREF1, then the measured voltage UDM of the valve group connection line of the control device is considered abnormal; wherein, when the timing variable T1 starts timing, if the difference UDM_ER is less than UREF1-ZHIHUAN, the timing variable T1 is reset to zero, and ZHIHUAN is a hysteresis setpoint.

4. The method as described in claim 3, characterized in that: The method of assuming that the measured voltage value UDM of the valve group connection line of the control device is abnormal also includes setting the abnormal status signal to a high level and maintaining it for a second delay time T2ref. This includes setting the abnormal status signal PL to a high level and starting the timer T2 when the timing variable T1 is greater than the first delay time T1ref; when the timing variable T1 is less than or equal to the first delay time T1ref, if the abnormal status signal PL is low, then the abnormal status signal PL remains low; if the abnormal status signal PL is high and T2≤T2ref, then the abnormal status signal PL remains low; if PL is high and T2>T2ref, then PL is set to a low level and the timer T2 is reset to zero.

5. A system for detecting and switching abnormal voltage measurements on the connection line of an ultra-high voltage flexible direct current valve group, characterized in that: include, The data acquisition module is configured to acquire the measured voltage value UDM of the valve group connection line of the control device, the measured voltage value UDM_OSYS of the valve group connection line of the redundant device, and the abnormal detection auxiliary judgment value UV. The intermediate value acquisition module is configured to compare the valve group connection line voltage measurement value UDM, the redundant device valve group connection line voltage measurement value UDM_OSYS, and the abnormal detection auxiliary judgment value UV to obtain the median value UMID among the three; the abnormal state judgment module is configured to consider the control device valve group connection line voltage measurement value UDM to be abnormal when the difference between the control device valve group connection line voltage measurement value UDM and the median value UMID is greater than the first reference value UREF1 and lasts for a first delay time T1ref. And, the measurement value setting module is configured to, when the abnormal state judgment module considers the control device valve group connection line voltage measurement value UDM to be abnormal, use the redundant device valve group connection line voltage measurement value UDM_OSYS or the connection line voltage value UDMCAL calculated based on the electrical quantity measured by the control device as the control device connection line voltage measurement value UDM0; wherein, the data acquisition module acquires the abnormal detection auxiliary judgment value UV, including, by calculating the abnormal detection auxiliary judgment value UV, or by acquiring the valve group connection line voltage measurement value through an additionally set second redundant device, as the abnormal detection auxiliary judgment value UV; wherein, through The anomaly detection auxiliary judgment value UV is obtained through calculation, including acquiring the pole line voltage value UDL and the neutral line voltage value UDN of the UHV flexible DC transmission system, and calculating the anomaly detection auxiliary judgment value UV according to UV=(UDL+UDN) / 2; wherein, the measurement value setting module calculates the connection line voltage value UDMCAL based on the electrical quantities measured by the control device, including acquiring the electrical quantities measured by the control device, including the pole line voltage value UDL, the three-phase valve side voltage values ​​UVCA, UVCB, and UVCC; and calculating the connection line voltage value UDMCAL according to the type of control device; wherein, if the control device is a high-end valve group device, then, If the control device is a low-end valve group device, then... Wherein, UDN is the neutral line voltage value; or, the measurement value setting module calculates the connection line voltage value UDMCAL based on the electrical quantities measured by the control device, including: acquiring the electrical quantities measured by the control device, including the pole line voltage value UDL, the three-phase submodule voltages UA_SUM, UB_SUM, and UC_SUM; calculating the connection line voltage value UDMCAL according to the type of control device; wherein, if the control device is a high-side valve group device, then, If the control device is a low-end valve group device, then, Where UDN is the neutral line voltage value.

6. The system as described in claim 5, characterized in that: The intermediate value acquisition module obtains the median value UMID among the three, including: if UDM > UDM_OSYS > UV or UV > UDM_OSYS > UDM, then UMID = UDM_OSYS; if UDM_OSYS > UDM > UV or UV > UDM > UDM_OSYS, then UMID = UDM; if UDM_OSYS > UV > UDM or UDM > UV > UDM_OSYS, then UMID = UV.

7. The system as described in claim 5, characterized in that: If the difference between the measured voltage UDM of the valve group connection line of the control device and the intermediate value UMID is greater than the first reference value UREF1, and this difference persists for a first delay time T1ref, the measured voltage UDM of the valve group connection line of the control device is considered abnormal. This includes obtaining the difference UDM_ER between the measured voltage UDM of the valve group connection line of the control device and the intermediate value UMID; when the difference UDM_ER is greater than the first reference value UREF1, the timing variable T1 starts timing until the timing variable T1 equals the first delay time T1ref, and the difference UDM_ER is always greater than the first reference value UREF1, then the measured voltage UDM of the valve group connection line of the control device is considered abnormal; wherein, when the timing variable T1 starts timing, if the difference UDM_ER is less than UREF1-ZHIHUAN, the timing variable T1 is reset to zero, and ZHIHUAN is a hysteresis setpoint.

8. The system as described in claim 7, characterized in that: When the abnormal state judgment module determines that the measured voltage value UDM of the valve group connection line of the control device is abnormal, it sets the abnormal state signal to a high level and continues for a second delay time T2ref. This includes: when the timing variable T1 is greater than the first delay time T1ref, the abnormal state signal PL is set to a high level and the timer T2 starts timing; when the timing variable T1 is less than or equal to the first delay time T1ref, if the abnormal state signal PL is low, the abnormal state signal PL remains low; if the abnormal state signal PL is high and T2≤T2ref, the abnormal state signal PL remains low; if PL is high and T2>T2ref, PL is set to a low level and the timer T2 is cleared.

9. A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor; characterized in that: When the processor executes the computer program, it implements the steps of the method for detecting and switching abnormal voltage measurements of UHV flexible direct valve group connection lines as described in any one of claims 1 to 4.

10. A computer-readable storage medium storing a computer program; characterized in that: When the computer program is executed by the processor, it implements the steps of the method for detecting and switching abnormal voltage measurements of UHV flexible direct valve group connection lines as described in any one of claims 1 to 4.

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