528 results about "Voltage rating" patented technology

The invention relates to an off-grid parallel operation starting method of an energy storage system, the energy storage system and a storage medium, and belongs to the technical field of energy storage. The host receives the phase locking synchronization completion signal and sends a voltage unification instruction to the slave after determining that the grid-connected slave completes phase locking synchronization, and the host and the slave are boosted from the black start voltage to the rated voltage based on the voltage unification instruction to complete parallel start, so that fluctuation caused by unstable voltage in the start process of the slave can be improved; the stability of the energy storage system in the off-grid parallel operation process is improved; the slave is started after being synchronized according to the black start voltage phase lock phase established by the host, so that the output voltage after the slave is started is consistent with the output voltage of the host, the voltage consistency of the parallel energy storage current device is high, ring current caused by voltage difference can be reduced, and the operation efficiency of the system is improved; and the slave is started after successful phase locking, so that the risk of starting failure can be reduced.

A converter system, e.g., for vehicle-to-vehicle charging, includes galvanically-isolated modular first and second converters having the same maximum voltage rating, a direct current (DC) voltage bus interconnecting the converters, and an electronic controller. An input voltage to the DC bus is converted into an output voltage via switching control signals to the modular converters. The system's voltage rating may equal the maximum of the input and / or output voltage, or it may equal the maximum input voltage and be about 50-percent of the maximum output voltage. The maximum input and output voltages may be equal. When the voltage rating is about 50-percent of the maximum input voltage, capacitors may be connected in parallel with the modular converters on an input side thereof. Switching circuits may be connected to the bus to control the conversion of the input voltage via switching control signals.

The invention discloses a switch cabinet operation reliability evaluation method, relates to the field of switch cabinets, and solves the problem of low accuracy of switch cabinet operation reliability evaluation caused by non-targeted test, and the method comprises the following steps: collecting rated voltage values and rated current values of multiple groups of driving plug-ins and power modules in a target switch cabinet; performing an electrical variable protection test on each group of driving plug-ins in the target switch cabinet to obtain an electrical variable protection test result of the corresponding driving plug-ins; performing an over-temperature protection test on each group of power modules in the target switch cabinet to obtain an over-temperature test result of the corresponding power module; performing an open-phase protection test on the target switch cabinet to obtain an open-phase test result corresponding to the target switch cabinet; and integrating all test results corresponding to the target switch cabinet, and evaluating the reliability of the target switch cabinet based on the test results. According to the invention, through targeted testing of different accessories in the switch cabinet, accurate evaluation of the operation reliability of the switch cabinet is realized.

The invention relates to the technical field of new energy automobile electric control, and discloses a self-adaptive voltage dynamic stability control method for a new energy automobile converter. The method comprises the following steps: acquiring a real-time voltage time sequence data sequence of the new energy automobile converter in an operation period; performing voltage disturbance characteristic analysis on the real-time voltage time sequence data sequence based on a rated voltage interval of the converter, and identifying voltage disturbance modal information of the converter; then, according to an embedded voltage control strategy library and a voltage stability threshold condition, an initial voltage regulation and control instruction sequence is generated in combination with voltage disturbance modal information of the converter; performing voltage change trend prediction on the voltage disturbance modal information of the converter to obtain predicted voltage disturbance modal information; performing voltage control compensation optimization on the initial voltage regulation and control instruction sequence based on the predicted voltage disturbance modal information to generate an optimized voltage regulation and control instruction sequence; and performing adaptive voltage regulation on the new energy automobile converter according to the optimized voltage regulation instruction sequence.

The invention relates to the technical field of switching power supplies, in particular to a self-locking flyback switching power supply circuit with overcurrent and overvoltage protection, which comprises a primary side control circuit, a power conversion circuit, a synchronous rectification circuit and an output circuit, and is characterized in that a self-locking circuit is electrically connected with an overvoltage detection circuit and an overcurrent detection circuit; wherein the over-current detection circuit is used for detecting whether output current exceeds rated current or not; the overvoltage detection circuit is used for detecting whether the output voltage exceeds the rated voltage; and the self-locking circuit is used for pulling down the starting voltage of the primary side control circuit and the synchronous rectification circuit to a low level when the output overvoltage or overcurrent is detected, so that the power conversion circuit stops working until the input voltage is disconnected. According to the invention, the defects of response speed, protection precision, cost and adaptability in over-current and over-voltage protection of the existing flyback switching power supply are overcome.

The invention provides a multi-path self-adaptive constant-voltage constant-current charging device, and the device comprises an input module which comprises a plurality of paths of input power supplies with the same rated voltage and limited power; the summarizing module is connected with each path of input power supply and combines the input power supplies into a single path for output; the conversion module is connected with the gathering module and is used for converting the single-path output voltage into target voltage and realizing constant-voltage output through a feedback loop; the detection module is connected with the input module and is used for detecting the effective path number of the input power supply and outputting a signal; and the control module dynamically adjusts the gain of the amplification circuit according to the output signal, and realizes constant current output by combining the current feedback of the conversion module. The summarizing module solves the problems of cost and size; the detection module and the control module jointly improve efficiency and stability; and meanwhile, a dynamic adjusting mechanism of the control module ensures constant-voltage and constant-current output under different input conditions. The modules operate cooperatively, so that the charging device is superior to the prior art in expansibility, efficiency and stability.

The invention discloses a cross-linked polyethylene insulating material for middle and high voltage cables and a preparation method of the cross-linked polyethylene insulating material. Comprising the following raw material components in parts by weight: 100 parts of a polyethylene base material, 1.0-2.5 parts of a peroxide cross-linking agent, 0.05-0.5 part of an anti-scorching agent, 0.1-5.0 parts of a water tree resistant additive, 0.1-1.0 part of a main antioxidant, 0.1-1.0 part of an auxiliary antioxidant, 0-2.0 parts of a processing aid and 0-0.5 part of a metal deactivator. The cross-linked polyethylene insulating material for the middle-high voltage cable is suitable for manufacturing a power cable insulating layer with the rated voltage of 10 kV or above. And the method is particularly suitable for application scenes with high requirements on processing stability, long-term reliability and energy efficiency.

The invention relates to the technical field of voltage compensation, in particular to a rapid compensation method for realizing stable voltage output of a distribution line in a transformer area. The method comprises the following steps: dividing a plurality of characteristic intervals according to the difference between each phase of voltage data and a standard voltage; determining a deviation characteristic value of the phase voltage according to the correlation degree between the phase voltage and each type of other data of the node, the maximum deviation value of the phase voltage and the maximum deviation value of each type of other data; according to the intersection-to-union ratio and the deviation characteristic value of each characteristic interval and each overrun interval, determining an influence characteristic value of the characteristic interval; determining a compensation coefficient of the phase voltage of the node according to the three-phase unbalance degree of each key node and the corresponding intermediate node and the influence characteristic value of the characteristic interval; and determining the reactive compensation amount according to the rated voltage value, the real-time voltage and the line impedance in response to the fact that the real-time voltage is located outside the preset interval. The method can improve the stability of voltage output of the distribution line in the transformer area.

The invention provides a multi-bridge-arm integrated valve tower structure, a high-voltage direct-current transformer and a power system. The multi-bridge-arm integrated valve tower structure comprises a high-voltage bridge arm branch, a multiplexing bridge arm branch, a low-voltage bridge arm branch, a high-voltage port and a low-voltage port. One end of the high-voltage bridge arm branch, one end of the low-voltage bridge arm branch and one end of the multiplexing bridge arm branch are connected; the high-voltage bridge arm branch comprises a plurality of first half-bridge sub-modules which are connected in series; the multiplexing bridge arm branch comprises a plurality of second half-bridge sub-modules which are connected in series; the low-voltage bridge arm branch comprises a plurality of full-bridge sub-modules which are connected in series; the number of the first half-bridge sub-modules, the number of the second half-bridge sub-modules and the number of the full-bridge sub-modules are in direct proportion to the voltage withstand level of the valve tower structure. According to the structure, the high-voltage bridge arm branch, the multiplexing bridge arm branch and the low-voltage bridge arm branch are connected in a T-shaped mode, the number of the first half-bridge sub-modules, the number of the second half-bridge sub-modules and the number of the full-bridge sub-modules are determined according to the voltage withstand level needed by the valve tower, and the structure can be suitable for voltages of different levels.

The invention relates to the technical field of energy storage converter control, and particularly discloses an adaptive virtual impedance control method for a grid-connected inverter in a fault state, which comprises the following steps of: acquiring an output voltage, and when the output voltage is smaller than a voltage threshold, determining that the grid-connected inverter is in a fault state; according to the output voltage, calculating the voltage drop of the rated voltage and the reactive current needing to be injected into the inverter; calculating a real part and an imaginary part of the virtual impedance according to the output voltage, the voltage drop of the rated voltage and the reactive current needing to be injected into the inverter; obtaining an output current, and calculating an adaptive virtual voltage according to the output current and the real part and the imaginary part of the virtual impedance; and revising an output voltage reference value by using the self-adaptive virtual voltage, and then carrying out double-loop control to generate a PWM (Pulse-Width Modulation) gate signal. According to the invention, the voltage drop is used as an action signal of the virtual impedance, and the inverter injects the reactive current proportional to the voltage drop to reduce the fault when the power grid has the fault.

The disclosure provides a power tool and power tool system, including: a first slot and a second slot; when the power tool is in a double-pack working state, battery packs are respectively arranged in the first slot and the second lot; when the power tool is in a single-pack working state, the battery pack is arranged in the first slot or the second slot, and both the double-pack working state and the single-pack working state provides a same rated voltage to the power tool.

The invention discloses a load matching method of a tested power supply and related equipment. The method comprises the following steps: acquiring rated voltage, rated current and rated power of a tested power supply, drawing a power supply parameter curve based on the group of parameters, and determining a current turning point from the power supply parameter curve; according to the magnitude relationship between the actual output voltage of the tested power supply and the voltage corresponding to the current turning point, the rated current or rated power is flexibly selected as a reference basis to determine the resistance value of each load in the load box; and finally, selecting a plurality of loads connected in parallel from the load box as test loads according to the actual output voltage, and ensuring that the actual output current of the tested power supply reaches the rated current or the actual output power reaches the rated power. The rated current or the rated power is dynamically switched through the current turning point to serve as a reference basis, the load requirements of the tested power supply in different voltage intervals are accurately adapted, and the adaptability of load matching is greatly improved.

The invention relates to the field of power system equipment detection, in particular to a residual magnetism measuring device and method for a large power transformer. The residual magnetism measuring device for the large-scale power transformer comprises the large-scale power transformer, a high-voltage bushing, a high-voltage neutral point bushing, a low-voltage bushing, an iron core outgoing line bushing, a first capacitor, a second capacitor, a detection impedor, a partial discharge instrument and a large-current generator, the capacitance of the first capacitor is 30pf-40pf and is matched with the capacitance of a transformer iron core, and the capacitance of the second capacitor is 300pf-400pf and is 10 times proportional to the capacitance of the first capacitor; the method comprises the following steps: carrying out a long-time induction withstand voltage and partial discharge test after a conventional test, measuring discharge amounts Q1, Q2 and Q3 at 0.5, 1 and 1.5 times of rated voltages, judging residual magnetism according to the difference value of the discharge amounts and an iron core grounding current, and if the residual magnetism exceeds the standard, magnetizing and demagnetizing by using a large current generator at the frequency of 150Hz. The method has the advantages that the residual magnetism is measured and evaluated in time, equipment faults are avoided, operation is easy and convenient, and adaptability is high.

The application relates to the field of power systems, in particular to a control switching method and device of a converter device in a power supply system, which can be applied to energy storage converters in new energy micro-grid, electrochemical energy storage power station and the like. In the method, the voltage of the converter device at the control switching moment is saved, and the voltage is taken as an initial value after switching, then the rated voltage is transitioned in a first time period, so that voltage and current distortion and regulation time in the control switching process can be reduced. Meanwhile, through given phase initial values, circulation between converter devices in a power supply system with multiple converter devices under asynchronous switching is avoided.

The invention discloses a pilot protection method for an offshore wind power low-frequency cable outgoing line, and belongs to the technical field of power system relay protection, the pilot protection method comprises the following steps: determining a voltage break variable according to acquired voltage information on two sides of a low-frequency cable line, and when the voltage break variable is greater than a preset rated voltage, starting protection and carrying out fault state judgment; according to the maximum value and the minimum value of the current of the current information of the two sides of the low-frequency cable line in the same data window, probability distribution of the current of the two sides of the low-frequency cable line is determined, and a divergence value K of the probability distribution is obtained; comparing the divergence value K value with a setting threshold value, and determining the types of internal and external faults of the low-frequency cable line; and executing corresponding protection operation according to the fault judgment result. According to the method, the current probability distribution difference of the two sides of the low-frequency cable line is extracted, the K-L divergence value K is calculated, and the protection criterion is constructed to perform internal and external fault judgment, so that the accuracy of the judgment result is improved, and the corresponding protection operation is quickly executed.

The invention relates to the technical field of power distribution network overhead line pole-mounted switches, and discloses an all-insulation vacuum circuit breaker which comprises a circuit breaker body, a plurality of sets of pole columns are arranged above the circuit breaker body, the top of each set of pole column is provided with an all-insulation quick-connection wire inlet terminal, and the side edge of each pole column is provided with an isolation knife static end. The front end of the isolation knife static end is provided with an isolation knife moving end, and the tail part of the isolation knife moving end is connected with an all-insulation quick-connection outgoing line terminal. According to the scheme, the condition of inter-phase short circuit or inter-phase flashover is eliminated, the problem that the isolation knife is bounced off or virtually closed due to the fact that instantaneous current is too large is avoided, and a key effect is achieved on effective closing of a circuit. Compared with a common inner cavity assembly type pole, the integrated casting solid-sealed pole has the advantages that the electrical performance is more stable and reliable, and the partial discharge capacity under rated voltage is greatly reduced. And the embedded electricity taking capacitor can be configured with controllers with different powers, a potential indicator and a temperature sensor, so that problems of the circuit or the circuit breaker body can be found in time and maintained in time.

The invention relates to an alternating-current fault ride-through control method and device for a grid-forming type wind generating set. The wind generating set is arranged in a direct-current power transmission system based on a diode rectification unit, and the method comprises the steps that a voltage error value is determined based on a measured value and a reference value of output voltage of a converter of the wind generating set, and the reference value of the output voltage is an alternating-current side rated voltage amplitude of the diode rectification unit; adjusting an active power reference value and a reference frequency and a frequency measurement value of the output voltage based on the voltage error value; and performing active power control on the wind generating set based on the adjusted active power reference value, and performing frequency control on the wind generating set based on the adjusted reference frequency and the frequency measurement value. By adopting the method and the device, whether the fan enters the fault ride-through strategy or not can be determined by adopting the local information voltage amplitude without additional fault information, and the fault current of the converter can be reduced.

The invention discloses a circuit for a high-voltage direct-hanging electric heater, and the circuit comprises a high-voltage pre-charging module which is used for inputting high-voltage alternating current and suppressing the surge current of the high-voltage alternating current; the full-bridge rectifier module is used for converting the high-voltage alternating current into direct current; the conversion and control module is used for isolating and converting the direct current and outputting rated voltage and required power of the electric heater based on the direct current, the full-bridge rectifier module is connected with the high-voltage pre-charging module and the conversion and control module, and the output end of the conversion and control module is connected with the electric heater.

The invention relates to the field of power system protection and control, in particular to a vehicle-network interactive charging station self-adaptive fault ride-through method and device considering power grid voltage support, and the method comprises the steps: collecting the voltage amplitude of a grid-connected point of a charging station at a main protection action moment, and if the voltage amplitude of the grid-connected point recovers to be more than 0.95 times of rated voltage, judging whether the grid-connected point recovers to be more than 0.95 times of rated voltage; active power control of the voltage source converter is switched into direct-current voltage control at the main protection action moment, the reactive power reference value is adjusted to be consistent with that before the fault, and the charging station recovers normal operation, otherwise, the discharging power reference value of the charging station is adjusted to be Pmax 2 at the main protection action moment, and the charging station recovers normal operation. And meanwhile, active power control of the voltage source converter is switched into direct-current voltage control, and a reactive power control reference value of the voltage source converter is adjusted to Qmax 2 until the voltage of the grid-connected point of the charging station is recovered to be more than 0.95 times of rated voltage. Corresponding control strategies are adopted according to different fault severity degrees, and the method can adapt to different fault severity degrees, different initial operation working conditions and the access number of the electric vehicles.

The invention provides an extra-high voltage hybrid direct current transmission fault recovery optimization control method, device and equipment, and relates to the technical field of extra-high voltage hybrid direct current transmission. The system comprises a plurality of sending end converter stations and a plurality of receiving end converter stations, and the plurality of receiving end converter stations are connected to different alternating current systems in a layered manner; the method comprises the following steps: when a receiving end has a fault, obtaining a sub-module capacitor voltage of a target receiving end converter station; based on the sub-module capacitor voltage and a preset sub-module capacitor rated voltage, calculating a power unbalance amount of the target receiving end converter station; and determining an active power setting value of the target receiving-end converter station based on the direct-current side input power and the power unbalance amount of the target receiving-end converter station, and controlling the target receiving-end converter station based on the active power setting value. According to the method, the fault degree can be prevented from being further deepened, so that the fault recovery speed of the hierarchical access system is accelerated.

A rated voltage transfer line includes: a rated voltage application part to which a first rated voltage is applied, at least one capacitor including a first terminal connected to the rated voltage application part and a second terminal that is grounded, a branch line part including a branch part electrically connected to the rated voltage application part and first and second branch lines branching and extending from the branch part, a first contact part electrically connected to a first end of the first branch line spaced apart from the branch part, and a second contact part electrically connected to a first end of the second branch line spaced apart from the branch part.

The utility model relates to the technical field of relay control, and provides a relay drive control circuit, which comprises an input control module, a voltage division control module, a comparator, a first capacitor, a first triode and a second triode, the control end of the input control module is connected with the first input end of the comparator and the base electrode of the second triode. A second input end of the comparator is connected with a rated voltage signal end through the voltage division control module, and an output end of the comparator is connected with a base electrode of the first triode; one end of the first capacitor is connected with the first input end of the comparator and the other end is grounded; an emitter of the first triode is connected with a rated voltage signal end, and a collector of the first triode is connected with a first contact of a relay to be driven and a holding voltage signal end; the emitter of the second triode is connected with the second contact of the relay to be driven, and the collector of the second triode is grounded. According to the circuit, the EMC problem is avoided, a plurality of electrolytic capacitors do not need to be connected in parallel, and the circuit cost is relatively low.

The invention provides a method, device and equipment for determining the position of an electric leakage cell in a battery pack, and the method comprises the steps: measuring the total voltage of the battery pack as a first voltage value through a first voltmeter and a second voltmeter which are connected in series; two probes of a first voltmeter are respectively connected with the total positive electrode of the battery pack and the shell of the battery pack to obtain a second voltage value, and two probes of a second voltmeter are respectively connected with the total negative electrode of the battery pack and the shell of the battery pack to obtain a third voltage value; if an absolute value of a difference value between half of the first voltage value and the second voltage value is greater than a first preset value, performing ratio calculation on the second voltage value and a rated voltage value of a single battery cell in the battery pack to obtain a first ratio, and determining the position of the electric leakage battery cell in the battery pack according to the first ratio; according to the invention, the position of the electric leakage cell in the battery pack can be determined.

The invention discloses a current limiting method and system for a virtual synchronous generator after a power grid fault. The method comprises the following steps: monitoring a ratio of a power grid voltage to a rated voltage; comparing the ratio with a voltage drop degree threshold value; when the ratio is smaller than a voltage drop degree threshold value, a fault current limiting strategy is started; when a current-limiting strategy stopping condition is reached, judging whether the amplitude of the power grid current is smaller than or equal to a current-limiting threshold value or not; if the amplitude of the power grid current is smaller than or equal to the current limiting threshold value, ending, otherwise, carrying out the fault current limiting strategy again; when the ratio is greater than or equal to the voltage drop degree threshold value, the fault current limiting strategy does not need to be started; wherein the fault current limiting strategy comprises an active ring adjustment strategy based on angular frequency deviation feedback and a reactive adjustment strategy based on an adaptive adjustment reactive droop coefficient. According to the invention, the response capability and the operation stability of the converter during sudden power grid disturbance can be improved.

A method can comprise determining, by a first controller comprising a processor, of a first vehicle, a first voltage rating of a first battery of the first vehicle and a state of charge of the first battery. In various embodiments, the method can further comprise determining, by the first controller, based on an output of a second controller of a second vehicle, a second voltage rating of a second battery of the second vehicle and a state of charge of the second battery. In further embodiments, the method can further comprise in response to a determination, by the first controller, that the first voltage rating matches the second voltage rating, transferring, by the first controller, power from the first battery to the second battery, wherein the state of charge of the first battery is greater than the state of charge of the second battery.

The invention discloses a multi-terminal flexible direct current system coordination control method and device, a multi-terminal flexible direct current system comprises a plurality of flexible interconnection devices, each flexible interconnection device is provided with an interconnection agent, and the adjacent flexible interconnection devices establish communication through the interconnection agents. The method comprises the following steps: outputting a current optimal droop coefficient and adjusting the direct current side output current of the current flexible interconnection equipment based on a droop coefficient optimization model pre-constructed in the current flexible interconnection equipment in combination with the direct current side output current, the direct current side output voltage and the alternating current side output power of the current flexible interconnection equipment, obtaining a direct current side output voltage reference value of the current flexible interconnection equipment by combining a direct current side rated voltage value of the current flexible interconnection equipment; through the proportional-integral controller, a power control instruction is output, coordination control over the current flexible interconnection equipment is completed, the influence of voltage deviation and uneven current shunting is reduced, more accurate voltage control and power distribution are achieved, and the overall performance of the system is improved.

A rated voltage transfer line includes: a rated voltage application part to which a first rated voltage is applied, at least one capacitor including a first terminal connected to the rated voltage application part and a second terminal that is grounded, a branch line part including a branch part electrically connected to the rated voltage application part and first and second branch lines branching and extending from the branch part, a first contact part electrically connected to a first end of the first branch line spaced apart from the branch part, and a second contact part electrically connected to a first end of the second branch line spaced apart from the branch part.

Disclosed in the present application is an electrolytic hydrogen production rectifier power supply operation control method, comprising an AC / DC converter first operates, and then a DC / DC converter starts; when the output voltage of a hydrogen production rectifier power supply is lower than a certain proportion value Z of a rated voltage, the DC / DC converter works in a step-down mode; and, when the output voltage of the hydrogen production rectifier power supply is greater than or equal to the certain proportion value Z of the rated voltage, the DC / DC converter exits from the step-down mode, all upper transistors of bridge arms of the DC / DC converter remain in a normally on state, all lower transistors of the bridge arms of the DC / DC converter remain in a normally off state, and the DC / DC converter remains in a pass-through state. In the method, in a low-load phase, both the AC-DC converter and the DC-DC work so as to achieve a good voltage regulation range; and in a high-load phase, the AC-DC works and the DC-DC is in a continues conduction working mode, such that the control and regulation of the output voltage changes from control by the output of the DC / DC unit to control by the output of the AD / DC unit, so as to achieve good energy-saving benefits.

The utility model provides a vehicle power grid system. The vehicle power grid system comprises first power receiving equipment, second power receiving equipment, a voltage conversion circuit and a voltage coordinator. The rated voltage of the first power receiving device is different from the rated voltage of the second power receiving device. The voltage conversion circuit comprises a first output end and a second output end, and the second output end is electrically connected with the grounding end; the first power receiving device is electrically connected between the first output end and the grounding end, and the voltage conversion circuit supplies power to the first power receiving device. The voltage coordinator comprises a first connecting end, a second connecting end and a third connecting end. The third connecting end is electrically connected with the grounding end; the voltage coordinator is electrically connected with the voltage conversion circuit through the first connecting end, the second powered device is electrically connected between the second connecting end and the grounding end, and the voltage coordinator supplies power to the second powered device through the second connecting end. According to the invention, the first power receiving device and the second power receiving device can be rapidly carried on the same vehicle power grid system, and the manufacturing cost of the vehicle power grid system is reduced.

The application provides a real-time monitoring device and method for air supplement amount of a Francis turbine unit of a hydropower plant, and relates to the field of Francis turbine units of hydropower plants.The device comprises a thermistor, an air supplement pipe, a current generator, a thermistor temperature sensor, a current regulator and a wind speed regulator, wherein the thermistor is fixed in the middle of the air supplement pipe, and the current generator generates rated voltage to heat the thermistor; the current regulator is used for real-time measurement of output current of the thermistor and records the change frequency of the output current; the wind speed regulator is used for measurement of wind speed at the air supplement pipe opening; and the thermistor temperature sensor is used for measurement of the temperature of the thermistor. The application fixes the thermistor in the air supplement pipe, determines the relationship curve between the air supplement amount and the output current, solves the problem that the air supplement amount of the Francis turbine unit cannot be monitored, and uses the thermistor principle to realize accurate measurement, is durable and not easy to be damaged, is convenient to install, can be introduced into a monitoring system, and can be monitored in real time on a host computer.