Monitoring system of flexible direct current converter valve

Abstract

The invention discloses a monitoring system of a flexible direct current converter valve, and relates to the technical field of converter valve monitoring, a geometric model of a power device is established through a simulation analysis module, heat flow distribution of the power device during actual operation is simulated, a temperature cloud picture is generated, and the highest temperature point in the temperature cloud picture is determined as an optimal monitoring position. Therefore, the limitation that the traditional method depends on experience or random selection is solved; the shell temperature monitoring module can directly perform temperature data acquisition on the temperature to-be-measured point determined by simulation, so that time consumption caused by repeated trial and error in a traditional method is avoided, and the acquired temperature data can reflect the actual temperature of the power device more truly; and finally, the data processing unit pre-processes the original temperature data and sends the original temperature data to the valve control system. According to the invention, the efficiency of temperature monitoring is improved, more accurate temperature acquisition of the power device can be realized, and temperature abnormity can be found and processed in time.

Description

Technical Field

[0001] This invention relates to the field of converter valve monitoring technology, and in particular to a monitoring system for a flexible DC converter valve. Background Technology

[0002] As a core component of flexible DC transmission systems, the operating status of flexible DC converter valves directly affects the stability and safety of the entire system. Maintenance of these valves primarily involves monitoring them through data acquisition and analysis within the submodules. The power devices within the flexible DC converter valves generate heat during operation. Poor heat dissipation or internal defects can lead to overheating, affecting their performance and lifespan, and even causing malfunctions. Therefore, real-time monitoring of the converter valves requires timely acquisition and handling of temperature anomalies to ensure the stable operation of both the converter valves and the flexible DC transmission system.

[0003] However, traditional methods for monitoring the temperature of flexible DC converter valves require multiple attempts at different monitoring locations based on experience to find hot spots, or random selection of a location on the casing for temperature measurement. This not only wastes a lot of time and resources, resulting in low temperature monitoring efficiency, but may also cause the monitoring location to deviate from the actual hot spot location. Consequently, the collected temperature data may not accurately reflect the actual temperature of the power devices, leading to misjudgments of the power device's temperature status and an inability to detect and handle temperature anomalies in a timely manner. This, in turn, affects the maintenance and decision-making of flexible DC converter valves and fails to ensure the stable operation of the flexible DC transmission system. Summary of the Invention

[0004] This invention provides a monitoring system for a flexible DC converter valve, which can simulate the heat flow distribution of power devices during actual operation and generate a temperature cloud map. The highest temperature point in the temperature cloud map is determined as the optimal monitoring location, i.e. the temperature to be measured point. This solves the limitations of traditional methods that rely on experience or random selection, and can effectively solve the problem of misjudging the temperature status of power devices and failing to detect and handle temperature anomalies in a timely manner in the prior art.

[0005] An embodiment of the present invention provides a monitoring system for a flexible DC converter valve, comprising: a simulation analysis module, a shell temperature monitoring module, and a data processing unit;

[0006] The simulation analysis module is used to generate a geometric model corresponding to each power device in the sub-module of the flexible DC converter valve based on the physical structure of the power device; to simulate the heat flow distribution of the power device during operation based on the thermal property parameters and cooling parameters of the power device, and to generate a simulation temperature cloud map of the power device; and to mark the point with the highest temperature in the simulation temperature cloud map as the temperature to be measured point.

[0007] The case temperature monitoring module is used to collect the case surface temperature corresponding to the temperature measurement point of each power device, and then transmit each case surface temperature to the data processing unit.

[0008] The data processing unit is used to preprocess the temperature of each shell surface and upload the preprocessed shell surface temperature to the external valve control system, so that the external valve control system can analyze the preprocessed shell surface temperature and output the temperature analysis results of the power device.

[0009] Preferably, the case temperature monitoring module is disposed on the metal component of the power device;

[0010] The metal component is at the same potential as the negative terminal of the DC capacitor in the submodule, and the metal component is connected to the negative terminal of the DC capacitor through a conductive material.

[0011] Preferably, it further includes: a saturation voltage drop monitoring module for acquiring the saturation voltage drop of the power device driver board; wherein the saturation voltage drop monitoring module is disposed on the driver board of the power device;

[0012] The saturation voltage drop monitoring module includes: a transistor, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a first diode, a second diode, and an operational amplifier;

[0013] The collector of the transistor is connected to the first port of the first resistor, and the emitter and collector of the transistor form a current path; the gate of the transistor is the input terminal of the control signal, and the gate of the transistor is used to control the conduction and turn-off of the power device.

[0014] The second port of the first resistor is connected to the anode of the first diode, and the cathode of the first diode is connected to the anode of the second diode; the cathode of the second diode is connected to the first port of the second resistor, and the second port of the second resistor is connected to a drive power supply for providing the voltage required to turn on the power device;

[0015] The second port of the second resistor is also connected to the first port of the third resistor, and the second port of the third resistor is connected to the non-inverting input of the operational amplifier;

[0016] The anode of the second diode is also connected to the first port of the fourth resistor, and the second port of the fourth resistor is connected to the inverting input of the operational amplifier.

[0017] The first port of the fifth resistor is connected to the second port of the third resistor, and the second port of the fifth resistor is connected to the output terminal of the operational amplifier.

[0018] Preferably, it further includes: a power consumption monitoring module;

[0019] The power consumption monitoring module is used to collect the current to be processed from the power source in the submodule and the voltage to be processed from the energy storage capacitor in the submodule, and transmit the current to be processed and the voltage to be processed to the data processing unit.

[0020] The data processing unit is further configured to generate a power consumption value based on the current to be processed and the voltage to be processed; wherein the power consumption value is used to characterize the operating power consumption of the board in the submodule.

[0021] Preferably, it further includes: a capacitor temperature monitoring module;

[0022] The capacitor temperature monitoring module is used to collect the capacitor temperature of the DC capacitor inside the submodule and transmit the capacitor temperature to the data processing unit.

[0023] The data processing unit is also used to preprocess the capacitor temperature and upload the preprocessed capacitor temperature to an external valve control system.

[0024] Preferably, the simulation analysis module is also used to perform thermal simulation on the three-dimensional model of the DC capacitor, determine the location of the hottest point in the DC capacitor based on the thermal simulation results, and mark the location of the hottest point in the DC capacitor as the connection point between the capacitor temperature monitoring module and the DC capacitor.

[0025] The capacitor temperature monitoring module is fixedly connected to the DC capacitor through the connection point.

[0026] Preferably, it further includes: a valve section temperature detection module;

[0027] The valve section temperature detection module is used to collect the first coolant temperature at the inlet of the cooling system and the second coolant temperature at the outlet of the cooling system in the valve section, and transmit the first coolant temperature and the second coolant temperature to the data processing unit.

[0028] The data processing unit is further configured to preprocess the first coolant temperature and the second coolant temperature, and upload the preprocessed first coolant temperature and the preprocessed second coolant temperature to an external valve control system.

[0029] Preferably, it also includes: a valve section water flow monitoring module;

[0030] The valve section water flow monitoring module is used to collect the first water flow at the inlet of the cooling system and the second water flow at the outlet of the cooling system in the valve section, and transmit the first water flow and the second water flow to the data processing unit.

[0031] The data processing unit is further configured to preprocess the first water flow rate and the second water flow rate, and upload the preprocessed first water flow rate and the preprocessed second water flow rate to an external valve control system.

[0032] Preferably, the valve section water flow monitoring module includes: an external clamp-on flow sensor or a turbine-type flow sensor.

[0033] Preferably, it also includes: a copper busbar temperature monitoring module;

[0034] The copper busbar temperature monitoring module is used to collect the copper busbar temperature at the AC output terminal of the submodule and transmit the copper busbar temperature to the data processing unit.

[0035] The data processing unit is also used to preprocess the copper busbar temperature and upload the preprocessed copper busbar temperature to an external valve control system.

[0036] The following benefits can be obtained by implementing the present invention:

[0037] This invention provides a monitoring system for flexible DC converter valves. The simulation analysis module of this invention establishes a geometric model of the power device, combining material thermal properties and cooling system parameters to simulate the heat flow distribution of the power device during actual operation and generate a temperature cloud map. The highest temperature point in the temperature cloud map is determined as the optimal monitoring location, i.e., the temperature measurement point, thus overcoming the limitations of traditional methods that rely on experience or random selection. Furthermore, the shell temperature monitoring module can directly collect temperature data from the temperature measurement point determined by the simulation, avoiding the time consumption of multiple trial and error in traditional methods. Moreover, each power device in this invention can obtain an independent temperature measurement point based on simulation analysis, enabling full-array temperature monitoring and ensuring that all potential hotspots are covered. This allows the collected temperature data to more accurately reflect the actual temperature of the power device. Finally, the data processing unit preprocesses the raw temperature data and sends it to the valve control system, achieving real-time interaction between the monitoring system and the valve control system to detect and handle abnormal temperature data. Therefore, this invention not only improves the efficiency of temperature monitoring but also achieves more accurate power device temperature acquisition, enabling timely detection and handling of temperature anomalies and ensuring the stable operation of the flexible DC transmission system. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the structure of a monitoring system for a flexible DC converter valve provided in an embodiment of the present invention.

[0039] Figure 2 This is a schematic diagram of the monitoring system structure of a flexible DC converter valve provided in another embodiment of the present invention.

[0040] Figure 3 This is a voltage drop sampling circuit diagram of a saturation voltage drop monitoring module provided in an embodiment of the present invention.

[0041] Figure 4 This is a circuit diagram of the current and voltage acquisition circuit of a power consumption monitoring module provided in an embodiment of the present invention.

[0042] Figure 5 This is a schematic diagram of the installation of an externally clamped flow sensor for a valve section water flow monitoring module according to an embodiment of the present invention.

[0043] Figure 6 This is a schematic diagram of the installation of an insertable thermocouple for a valve section temperature detection module provided in an embodiment of the present invention.

[0044] Figure 7 This is a connection diagram of internal components of a monitoring system provided in an embodiment of the present invention. Detailed Implementation

[0045] 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 some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] like Figure 1 The diagram shown is a flowchart of a monitoring system for a flexible DC converter valve according to an embodiment of the present invention. The monitoring system for the flexible DC converter valve includes: a simulation analysis module, a shell temperature monitoring module, and a data processing unit.

[0047] The simulation analysis module is used to generate a geometric model corresponding to each power device in the sub-module of the flexible DC converter valve based on the physical structure of the power device; to simulate the heat flow distribution of the power device during operation based on the thermal property parameters and cooling parameters of the power device, and to generate a simulation temperature cloud map of the power device; and to mark the point with the highest temperature in the simulation temperature cloud map as the temperature to be measured point.

[0048] The case temperature monitoring module is used to collect the case surface temperature corresponding to the temperature measurement point of each power device, and then transmit each case surface temperature to the data processing unit.

[0049] The data processing unit is used to preprocess the temperature of each shell surface and upload the preprocessed shell surface temperature to the external valve control system, so that the external valve control system can analyze the preprocessed shell surface temperature and output the temperature analysis results of the power device.

[0050] In a schematic embodiment of the present invention, the shell temperature monitoring module can be used to monitor the operating temperature of the sub-module in the flexible DC converter valve. First, the heat flow distribution of the power device during actual operation can be simulated by the simulation analysis module, and the hottest monitoring location can be determined, that is, the temperature measurement point corresponding to the highest temperature in the temperature cloud map can be determined. This allows the shell temperature monitoring module to directly collect temperature data from the temperature measurement point determined by the simulation, thereby achieving more accurate temperature monitoring of the power device.

[0051] In a preferred embodiment, the case temperature monitoring module is disposed on the metal component of the power device;

[0052] The metal component is at the same potential as the negative terminal of the DC capacitor in the submodule, and the metal component is connected to the negative terminal of the DC capacitor through a conductive material.

[0053] It is understandable that when installing the temperature sensor of the casing temperature monitoring module, the temperature sensor is installed at the same potential as the negative terminal of the DC capacitor. Since the negative terminal of the DC capacitor is usually at a low potential or grounded, selecting a metal part (such as the heat sink base of the power device or the module frame) at the same potential as it to install the temperature sensor can ensure that the sensor is isolated from the high-voltage area. Thus, the embodiments of the present invention can prevent electric shock accidents caused by insulation failure.

[0054] In a preferred embodiment, such as Figure 2 As shown, the monitoring system for the flexible DC converter valve of the present invention further includes: a saturation voltage drop monitoring module for collecting the saturation voltage drop of the power device driver board, a power consumption monitoring module, a capacitor temperature monitoring module, a valve section temperature detection module, a valve section water flow monitoring module, and a copper busbar temperature monitoring module. Thus, through these modules, the embodiments of the present invention can obtain various operating indicators of the converter valve in real time, and can be installed without affecting the function of the converter valve sub-modules themselves, minimizing the impact on the converter valve body.

[0055] In a preferred embodiment, the data processing unit is a sampling board. The shell temperature monitoring module has two crimped devices at the grounding end, which transmit the temperature signal to the sampling board via a cable.

[0056] Each power device's driver board has a sampling circuit for a saturation voltage drop monitoring module. The sampling circuit sends the conduction voltage drop signal to the sampling board via a cable.

[0057] The power consumption monitoring module can connect the onboard current sensor on the sampling board in series with the power supply line of the capacitor-power-harvesting power supply in the submodule to obtain the input current of the power-harvesting power supply, so as to calculate the power consumption of the secondary board in the submodule.

[0058] The capacitor temperature monitoring module collects the temperature of the DC capacitor and sends it to the sampling board via a cable.

[0059] The valve section temperature detection module and valve section water flow monitoring module of the valve section water branch are located at the valve section inlet / outlet, which are external to the sub-modules and are connected to the sampling board, so that water temperature signal and flow signal can be sent up.

[0060] The copper busbar temperature monitoring module corresponding to the copper busbar at the AC end of the submodule can monitor the temperature corresponding to the highest temperature position of the copper busbar, and the copper busbar temperature monitoring module is connected to the sampling board via a data cable.

[0061] Finally, the monitoring signals can be sent to the submodule unit control board via the sampling board and then uploaded to the external valve control system. This allows the external valve control system to analyze the pre-processed shell temperature and output the temperature analysis results of the power devices, enabling maintenance personnel to perform analysis and maintenance work.

[0062] In a preferred embodiment, the monitoring system for the flexible DC converter valve of the present invention further includes: a saturation voltage drop monitoring module for collecting the saturation voltage drop of the power device drive board; wherein the saturation voltage drop monitoring module is disposed on the drive board of the power device;

[0063] The saturation voltage drop monitoring module includes: a transistor, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a first diode, a second diode, and an operational amplifier;

[0064] The collector of the transistor is connected to the first port of the first resistor, and the emitter and collector of the transistor form a current path; the gate of the transistor is the input terminal of the control signal, and the gate of the transistor is used to control the conduction and turn-off of the power device.

[0065] The second port of the first resistor is connected to the anode of the first diode, and the cathode of the first diode is connected to the anode of the second diode; the cathode of the second diode is connected to the first port of the second resistor, and the second port of the second resistor is connected to a drive power supply for providing the voltage required to turn on the power device;

[0066] The second port of the second resistor is also connected to the first port of the third resistor, and the second port of the third resistor is connected to the non-inverting input of the operational amplifier;

[0067] The anode of the second diode is also connected to the first port of the fourth resistor, and the second port of the fourth resistor is connected to the inverting input of the operational amplifier.

[0068] The first port of the fifth resistor is connected to the second port of the third resistor, and the second port of the fifth resistor is connected to the output terminal of the operational amplifier.

[0069] Specifically, such as Figure 3 The voltage drop sampling circuit diagram of the saturation voltage drop monitoring module shown includes a transistor, resistor R1 (i.e., the first resistor), resistor R2 (i.e., the second resistor), resistor R3 (i.e., the third resistor), resistor R4 (i.e., the fourth resistor), and resistor R... f (i.e., the fifth resistor), diode D1 (i.e., the first diode), diode D2 (i.e., the second diode), and operational amplifier (i.e., the operational amplifier).

[0070] In this circuit, resistor R1 is connected in series with the emitter (E) of the transistor, serving as a current limiter; resistors R2 and R3 participate in voltage division and circuit protection; and resistor R4 acts as the input resistor for the operational amplifier, matching the signal input. f The feedback resistor of the operational amplifier determines the amplification factor. Diodes D1 and D2 provide overvoltage protection to prevent abnormal voltage from damaging subsequent circuits. Capacitor C is connected in parallel across the transistor for filtering and voltage stabilization, while the operational amplifier (IN+, IN-, GND, Vout) amplifies the sampled signal.

[0071] It is understood that the acquisition circuit corresponding to the saturation voltage drop monitoring module of the present invention includes an input circuit, a protection and voltage divider circuit, and a signal amplification circuit;

[0072] The input circuit is as follows: the collector (C) of the transistor is connected to the main power supply (such as the bus voltage) or to the power supply through the load, and the emitter (E) is connected to the subsequent circuit through resistor R1. Capacitor C is connected in parallel across the transistor to filter out high-frequency interference.

[0073] The protection and voltage divider circuit consists of resistors R2 (the second resistor), R3 (the third resistor), diodes D1 (the first diode), and D2 (the second diode). Diodes D1 (the first diode) and D2 (the second diode) are connected in reverse parallel to limit the voltage amplitude.

[0074] The signal amplification circuit is as follows: the sampled signal is input to the non-inverting input of the operational amplifier via resistor R4, and the inverting input of the operational amplifier is connected to resistor R... f It is connected to the output terminal (Vout) to form a closed-loop amplifier circuit.

[0075] The working principle of the voltage drop sampling circuit of the present invention is as follows: when the transistor (power device) is turned on, a saturation voltage drop (V) is generated between its collector and emitter terminals. CE This voltage is transmitted to subsequent circuits. D1 and D2 clamp the op-amp to prevent reverse voltage or overvoltage from damaging it. The operational amplifier uses R... fR4 serves as a feedback element, which proportionally amplifies the input saturation voltage drop signal and ultimately outputs a recognizable voltage signal (i.e., saturation voltage drop) for further processing by the sampling board (such as analog-to-digital conversion), thereby enabling accurate monitoring of the saturation voltage drop of the power device in the on-state.

[0076] Indicatively, this invention can also add a filter unit and an AD conversion circuit to the voltage drop sampling circuit, thereby converting the analog signal into a digital signal and sending it to the control board and valve control equipment. Since the collector and emitter electrodes are at very high voltage levels when the device is turned off, the electromagnetic environment of the saturated voltage drop acquisition circuit is harsh, with high current and voltage changes potentially causing radiated interference up to 30V / m, as well as surges and fast transient pulses that may interfere with the measurement lines. Therefore, this invention can also add a shielding cover to the driver board to reduce interference.

[0077] In a preferred embodiment, the monitoring system for the flexible DC converter valve of the present invention further includes: a power consumption monitoring module;

[0078] The power consumption monitoring module is used to collect the current to be processed from the power source in the submodule and the voltage to be processed from the energy storage capacitor in the submodule, and transmit the current to be processed and the voltage to be processed to the data processing unit.

[0079] The data processing unit is further configured to generate a power consumption value based on the current to be processed and the voltage to be processed; wherein the power consumption value is used to characterize the operating power consumption of the board in the submodule.

[0080] Indicative, such as Figure 4 The diagram shows the current and voltage acquisition circuit structure of the power consumption monitoring module. This invention adds a current sampling circuit between the module capacitor and the power source. Optionally, the current sampling can employ a Hall sensor with electromagnetic isolation or a resistor-isolated voltage divider current sampling circuit with resistive isolation. After the current signal is sent to the sampling board and then to the valve control, it can be multiplied by the acquired submodule capacitor voltage to obtain the real-time power consumption of the secondary board.

[0081] In a preferred embodiment, the monitoring system for the flexible DC converter valve of the present invention further includes: a capacitor temperature monitoring module;

[0082] The capacitor temperature monitoring module is used to collect the capacitor temperature of the DC capacitor inside the submodule and transmit the capacitor temperature to the data processing unit.

[0083] The data processing unit is also used to preprocess the capacitor temperature and upload the preprocessed capacitor temperature to an external valve control system.

[0084] In illustratively, the simulation analysis module of the present invention is also used to perform thermal simulation on the three-dimensional model of the DC capacitor, determine the location of the hottest point in the DC capacitor based on the thermal simulation results, and mark the location of the hottest point in the DC capacitor as the connection point between the capacitor temperature monitoring module and the DC capacitor.

[0085] The capacitor temperature monitoring module is fixedly connected to the DC capacitor through the connection point.

[0086] It is understood that, in this embodiment of the invention, the simulation analysis module performs thermal simulation on the three-dimensional model of the DC capacitor, which can accurately simulate the temperature distribution of the capacitor during actual operation and quickly locate the hottest point in the capacitor, i.e., the point with the highest temperature. Using this point as the connection point between the capacitor temperature monitoring module and the DC capacitor ensures that the monitored temperature data is the most representative, thereby improving the accuracy of the entire monitoring system.

[0087] Optionally, the present invention can also use an external thermistor to measure the capacitor temperature. Since the capacitor cannot be directly soldered, a thermal coupling agent is used to attach the NTC temperature sensor to the corresponding position, that is, to the hottest point of the DC capacitor.

[0088] In a preferred embodiment, the monitoring system for the flexible DC converter valve of the present invention further includes: a valve section temperature detection module;

[0089] The valve section temperature detection module is used to collect the first coolant temperature at the inlet of the cooling system and the second coolant temperature at the outlet of the cooling system in the valve section, and transmit the first coolant temperature and the second coolant temperature to the data processing unit.

[0090] The data processing unit is further configured to preprocess the first coolant temperature and the second coolant temperature, and upload the preprocessed first coolant temperature and the preprocessed second coolant temperature to an external valve control system.

[0091] In a preferred embodiment, the monitoring system for the flexible DC converter valve of the present invention further includes: a valve section water flow monitoring module;

[0092] The valve section water flow monitoring module is used to collect the first water flow at the inlet of the cooling system and the second water flow at the outlet of the cooling system in the valve section, and transmit the first water flow and the second water flow to the data processing unit.

[0093] The data processing unit is further configured to preprocess the first water flow rate and the second water flow rate, and upload the preprocessed first water flow rate and the preprocessed second water flow rate to an external valve control system.

[0094] In a preferred embodiment, the valve section water flow monitoring module includes: an external clamp-on flow sensor or a turbine-type flow sensor.

[0095] like Figure 5 The schematic diagram of the clamp-on flow sensor installation for the valve section water flow monitoring module shows that, to prevent leakage caused by the opening, an ultrasonic clamp-on flow sensor can be selected in this invention. Indicatively, during installation, a 2-3mm layer of coupling agent can be evenly applied to the emitting surface of the sensor. Then, the sensor is installed on the pipe surface after the paint, rust, and anti-corrosion layer have been removed, according to the required installation distance, and secured with steel straps or wire ropes.

[0096] Optional, such as Figure 6 As shown, embodiments of the present invention can also use insertion thermocouples to measure the inlet and outlet water temperatures of the valve section. Specifically, corresponding holes can be drilled in the inlet and outlet water pipes of the valve section, and thermocouples can be inserted into the water pipes to directly measure the water temperature. Optionally, indirect measurement methods such as thermistors can also be used, and the inlet and outlet water temperatures can be obtained through calculation.

[0097] In a preferred embodiment, the monitoring system for the flexible DC converter valve of the present invention further includes: a copper busbar temperature monitoring module;

[0098] The copper busbar temperature monitoring module is used to collect the copper busbar temperature at the AC output terminal of the submodule and transmit the copper busbar temperature to the data processing unit.

[0099] The data processing unit is also used to preprocess the copper busbar temperature and upload the preprocessed copper busbar temperature to an external valve control system.

[0100] Indicatively, this invention can simulate the copper busbar process, thereby adjusting the precision and mesh division of the simulation model to determine the temperature acquisition points of the copper busbar. Optionally, embodiments of this invention can also use thermocouples or fiber optic temperature sensors that meet the measurement requirements to measure the temperature of the copper busbar.

[0101] In a preferred embodiment, such as Figure 7 The diagram shows the internal component connections of the monitoring system. The shell temperature monitoring module is located in... Figure 7 The corresponding NTC temperature sensor is associated with the water-cooled plate (such as the water-cooled plate position corresponding to IGBT1-IGBT4). The working principle of the case temperature monitoring module is as follows: by monitoring the temperature of the water-cooled plate where the IGBT is located, the case temperature status of the power device (IGBT) can be indirectly reflected. The NTC sensor collects the temperature signal and transmits it to the sampling board.

[0102] Saturation pressure drop monitoring module in Figure 7Although the internal circuitry is shown in detail, the IGBT driver board is the key component of the saturation voltage drop monitoring module. The working principle of the saturation voltage drop monitoring module is as follows: the driver board integrates a conduction voltage drop sampling circuit to collect the IGBT saturation voltage drop signal. Figure 7 The connection relationship of the IGBTs on the driver board implies the implementation path of this monitoring function.

[0103] Power consumption monitoring module in Figure 7 The corresponding sensors are the current sensor and the module capacitor voltage sensor in the power supply circuit. Figure 7 (Not given), its working principle is: the input current of the power supply is collected by the current sensor, and combined with the collected module capacitor voltage, the power consumption of the secondary board (such as the driver board) can be calculated.

[0104] Capacitor temperature monitoring module Figure 7 The corresponding sensor is the NTC temperature sensor next to the module capacitor. Its working principle is to directly attach or approach the DC capacitor through the NTC sensor to collect the surface temperature of the capacitor and monitor its operating status.

[0105] Valve section temperature detection module and valve section water flow monitoring module Figure 7 The two sensors correspond to the external clamp-on flow sensor at the outlet of the valve section and the NTC temperature sensor at the outlet of the valve section, respectively.

[0106] Copper busbar temperature monitoring module Figure 7 The corresponding element is the NTC temperature sensor on the copper busbar. Its working principle is as follows: by installing an NTC temperature sensor on the hottest spot of heat dissipation on the copper busbar, the temperature of the copper busbar can be monitored in real time to prevent overheating failure.

[0107] It can be understood that the case temperature monitoring module of the present invention indirectly reflects the case temperature status of the power device (IGBT) by monitoring the temperature of the water-cooled plate where the IGBT is located, thus avoiding the interference and errors that may be caused by directly measuring the temperature of the power device, and improving the accuracy and reliability of temperature monitoring.

[0108] The saturation voltage drop monitoring module can collect the saturation voltage drop signal of IGBT in real time through the on-state voltage drop sampling circuit integrated on the driver board, thereby reflecting the on-state and health of the power device.

[0109] The power consumption monitoring module collects the input current of the power supply and the voltage of the module capacitor to calculate the power consumption of the secondary board, thereby achieving accurate monitoring of the internal power consumption of the sub-module and reducing the risk of system overheating and failure due to excessive power consumption.

[0110] Furthermore, the capacitor temperature monitoring module directly attaches to or approaches the DC capacitor via an NTC sensor to collect the capacitor surface temperature, enabling real-time monitoring of the capacitor's operating status. This improves the accuracy and timeliness of capacitor temperature monitoring and ensures the stable operation of the system.

[0111] The valve section temperature detection module monitors the inlet and outlet water temperatures of the valve section cooling system, which reflects the overall temperature status of the valve section, enabling subsequent evaluation of the cooling system's performance and ensuring the safe operation of the valve section.

[0112] The valve section water flow monitoring module can monitor the inlet and outlet water flow of the valve section cooling system in real time to ensure that the water flow of the cooling system meets the requirements and prevent overheating problems caused by insufficient water flow.

[0113] The copper busbar temperature monitoring module can monitor the copper busbar temperature in real time by installing an NTC temperature sensor at the hottest point of heat dissipation on the copper busbar, thereby improving the ability to detect and handle abnormal copper busbar temperatures in a timely manner.

[0114] In summary, this invention achieves comprehensive monitoring of various operational indicators of the flexible DC converter valve through precise monitoring and real-time data transmission of each monitoring module. Furthermore, real-time monitoring and early warning systems enable timely detection and handling of faults, preventing system downtime and increased maintenance costs caused by malfunctions. The collaborative operation of the various monitoring modules in this invention enables comprehensive and accurate monitoring of the system, improving system safety and reliability and ensuring the stable operation of the power system.

[0115] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A monitoring system for a flexible DC converter valve, characterized in that, include: Simulation analysis module, shell temperature monitoring module, and data processing unit; The simulation analysis module is used to generate a geometric model corresponding to each power device in the sub-module of the flexible DC converter valve based on the physical structure of the power device; to simulate the heat flow distribution of the power device during operation based on the thermal property parameters and cooling parameters of the power device, and to generate a simulation temperature cloud map of the power device; and to mark the point with the highest temperature in the simulation temperature cloud map as the temperature to be measured point. The case temperature monitoring module is used to collect the case surface temperature corresponding to the temperature measurement point of each power device, and then transmit each case surface temperature to the data processing unit. The data processing unit is used to preprocess the temperature of each shell surface and upload the preprocessed shell surface temperature to the external valve control system, so that the external valve control system can analyze the preprocessed shell surface temperature and output the temperature analysis results of the power device.

2. The monitoring system for a flexible DC converter valve as described in claim 1, characterized in that, The case temperature monitoring module is mounted on the metal component of the power device; The metal component is at the same potential as the negative terminal of the DC capacitor in the submodule, and the metal component is connected to the negative terminal of the DC capacitor through a conductive material.

3. The monitoring system for a flexible DC converter valve as described in claim 2, characterized in that, It also includes: a saturation voltage drop monitoring module for collecting the saturation voltage drop of the power device driver board; wherein the saturation voltage drop monitoring module is disposed on the driver board of the power device; The saturation voltage drop monitoring module includes: a transistor, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a first diode, a second diode, and an operational amplifier; The collector of the transistor is connected to the first port of the first resistor, and the emitter and collector of the transistor form a current path; the gate of the transistor is the input terminal of the control signal, and the gate of the transistor is used to control the conduction and turn-off of the power device. The second port of the first resistor is connected to the anode of the first diode, and the cathode of the first diode is connected to the anode of the second diode; the cathode of the second diode is connected to the first port of the second resistor, and the second port of the second resistor is connected to a drive power supply for providing the voltage required to turn on the power device; The second port of the second resistor is also connected to the first port of the third resistor, and the second port of the third resistor is connected to the non-inverting input of the operational amplifier; The anode of the second diode is also connected to the first port of the fourth resistor, and the second port of the fourth resistor is connected to the inverting input of the operational amplifier. The first port of the fifth resistor is connected to the second port of the third resistor, and the second port of the fifth resistor is connected to the output terminal of the operational amplifier.

4. The monitoring system for a flexible DC converter valve as described in claim 3, characterized in that, It also includes: a power consumption monitoring module; The power consumption monitoring module is used to collect the current to be processed from the power source in the submodule and the voltage to be processed from the energy storage capacitor in the submodule, and transmit the current to be processed and the voltage to be processed to the data processing unit. The data processing unit is further configured to generate a power consumption value based on the current to be processed and the voltage to be processed; wherein the power consumption value is used to characterize the operating power consumption of the board in the submodule.

5. The monitoring system for a flexible DC converter valve as described in claim 4, characterized in that, Also includes: Capacitor temperature monitoring module; The capacitor temperature monitoring module is used to collect the capacitor temperature of the DC capacitor inside the submodule and transmit the capacitor temperature to the data processing unit. The data processing unit is also used to preprocess the capacitor temperature and upload the preprocessed capacitor temperature to an external valve control system.

6. The monitoring system for a flexible DC converter valve as described in claim 5, characterized in that, The simulation analysis module is also used to perform thermal simulation on the three-dimensional model of the DC capacitor, determine the location of the hottest point in the DC capacitor based on the thermal simulation results, and mark the location of the hottest point in the DC capacitor as the connection point between the capacitor temperature monitoring module and the DC capacitor. The capacitor temperature monitoring module is fixedly connected to the DC capacitor through the connection point.

7. The monitoring system for a flexible DC converter valve as described in claim 6, characterized in that, Also includes: Valve section temperature detection module; The valve section temperature detection module is used to collect the first coolant temperature at the inlet of the cooling system and the second coolant temperature at the outlet of the cooling system in the valve section, and transmit the first coolant temperature and the second coolant temperature to the data processing unit. The data processing unit is further configured to preprocess the first coolant temperature and the second coolant temperature, and upload the preprocessed first coolant temperature and the preprocessed second coolant temperature to an external valve control system.

8. The monitoring system for a flexible DC converter valve as described in claim 7, characterized in that, Also includes: Valve section water flow monitoring module; The valve section water flow monitoring module is used to collect the first water flow at the inlet of the cooling system and the second water flow at the outlet of the cooling system in the valve section, and transmit the first water flow and the second water flow to the data processing unit. The data processing unit is further configured to preprocess the first water flow rate and the second water flow rate, and upload the preprocessed first water flow rate and the preprocessed second water flow rate to an external valve control system.

9. The monitoring system for a flexible DC converter valve as described in claim 8, characterized in that, The valve section water flow monitoring module includes: an external clamp-on flow sensor or a turbine-type flow sensor.

10. The monitoring system for a flexible DC converter valve as described in claim 9, characterized in that, Also includes: Copper busbar temperature monitoring module; The copper busbar temperature monitoring module is used to collect the copper busbar temperature at the AC output terminal of the submodule and transmit the copper busbar temperature to the data processing unit. The data processing unit is also used to preprocess the copper busbar temperature and upload the preprocessed copper busbar temperature to an external valve control system.

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