Fault diagnosis and correction device for sensor on converter

By designing a sensor fault diagnosis and correction device on the converter including a fault estimator and a controller, the problem of distortion of the sensor measured value is solved, and effective tracking of the steady-state voltage and current of the converter is achieved, and the reliability and safety of the system are improved.

CN119945392APending Publication Date: 2025-05-06NORTHEAST GASOLINEEUM UNIV
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Patent Information

Application Number
CN202411934493.6
Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Filing Date
2024-12-26
Publication Date
2025-05-06

AI Technical Summary

Technical Problem

The measured value of the sensor on the converter causes the duty cycle to be distorted, which in turn causes the voltage and current to deviate from the desired steady-state value, affecting the performance of the energy conversion system.

Method used

Design a device that includes an output and input current sensor, a voltage sensor, a fault estimator and a controller to estimate sensor failures and correct measurement values ​​through real-time measurement and calculation to ensure the signal received by the controller is accurate.

Benefits of technology

Real-time diagnosis and correction of voltage and current sensor faults is realized, ensuring steady-state tracking of the converter in various sensor fault conditions, and improving the reliability and safety of the converter circuit.

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Abstract

The invention relates to the technical field of sensors, in particular to a fault diagnosis and correction device for a sensor on a converter, which comprises a current sensor fault estimator, an input end current sensor fault estimator and an output end current estimator, wherein the current sensor fault estimator is used for calculating a theoretical current output value based on an input measurement value of the input end current sensor; fault estimation of the output end current sensor is obtained through calculation based on the theoretical current output value and an output end measurement value of the output end current sensor, and an input value of a controller current estimation closed loop is obtained through calculation based on the fault estimation of the output end current sensor, the measured output current value and a set output current reference value; and the controller is used for establishing an error analysis system based on the real-time input value of the controller current estimation closed loop and the input value of the controller voltage estimation closed loop to output a corrected voltage square wave. According to the invention, the reliability and safety of converter circuits such as a Boost converter and the like can be improved.
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Description

Technical Field

[0001] The invention relates to the technical field of sensors, and in particular to a sensor fault diagnosis and correction device on a converter. Background Art

[0002] DC power electronic converters can increase the amplitude of DC voltage and play an important role in power and energy conversion systems. The output voltage and output current of the converter are two important indicators of the converter. The control feedback circuit can ensure that these two indicators track the expected steady-state values. Due to the aging of sensor equipment and some unknown reasons, the measurement values ​​of voltage sensors and current sensors will be distorted. Therefore, the wrong measurement values ​​sent to the controller will cause duty cycle distortion, which will cause the voltage and current to deviate from the expected steady-state values, which will lead to the performance deterioration of the entire energy conversion system or even the failure of the entire system. Summary of the invention

[0003] In view of this, the object of the present invention is to provide a sensor fault diagnosis and correction device on a converter to solve the problem that erroneous measurement values ​​sent to the controller will cause duty cycle distortion, thereby causing the voltage and current to deviate from the desired steady-state values.

[0004] Based on the above purpose, the present invention provides a sensor fault diagnosis and correction device on a converter, including an output current sensor, an output voltage sensor, an input current sensor, an input voltage sensor, a current sensor fault estimator, a voltage sensor fault estimator and a controller, wherein:

[0005] The output terminal current sensor is used to measure the output terminal current of the converter, and the output terminal voltage sensor is used to measure the output terminal voltage of the converter;

[0006] The input terminal current sensor is used to measure the input terminal current of the converter, and the input terminal voltage sensor is used to measure the input terminal voltage of the converter;

[0007] The current sensor fault estimator is used to calculate a theoretical current output value based on an input measurement value of the input-end current sensor, and to calculate a fault estimate of the output-end current sensor based on the theoretical current output value and the output-end measurement value of the output-end current sensor, and to calculate an input value of a controller current estimation closed loop based on the fault estimate of the output-end current sensor, the measured output current value and the set output current reference value;

[0008] The voltage sensor fault estimator is used to calculate a theoretical voltage output value based on an input measurement value of the input voltage sensor, and to calculate a fault estimation of the output voltage sensor based on the theoretical voltage output value and the output measurement value of the output voltage sensor, and to calculate an input value of a controller voltage estimation closed loop based on the fault estimation of the output voltage sensor, the measured output voltage value and the set output voltage reference value;

[0009] The controller is used to establish a voltage square wave after the error analysis system output is corrected based on the real-time input value of the controller current estimation closed loop and the input value of the controller voltage estimation closed loop.

[0010] Optionally, the output fault estimation of the output-end current sensor=the measured value of the output-end current sensor-theoretical current output value.

[0011] Optionally, the input value of the controller current estimation closed loop = (measured output current value - fault estimation of the output current sensor) - a set output current reference value.

[0012] Optionally, the output fault estimate of the voltage sensor=measured value of the output voltage sensor-theoretical voltage output value.

[0013] Optionally, the controller voltage estimation closed-loop input value = (measured output voltage value - fault estimation of the output voltage sensor) - a set output voltage reference value.

[0014] Optionally, the device further comprises a limiter, which is used to receive the modified voltage square wave and adjust the amplitude of the modified voltage square wave to a predetermined value.

[0015] Optionally, the device further comprises a pulse width modulator, and the pulse width modulator is used to adjust the pulse width of the corrected voltage square wave.

[0016] The device is arranged on the converter when in use, measures the output current of the converter by the output current sensor, measures the output voltage of the converter by the output voltage sensor, measures the input current of the converter by the input current sensor, measures the input voltage of the converter by the input voltage sensor, calculates the theoretical current output value based on the input measurement value of the input current sensor by the current sensor fault estimator, and obtains the fault estimation of the output current sensor based on the theoretical current output value and the output measurement value of the output current sensor, and calculates the output current value and the set output current value based on the fault estimation of the output current sensor. The current reference value is calculated to obtain the input value of the controller current estimation closed loop; the theoretical voltage output value is calculated based on the input measurement value of the input voltage sensor by the voltage sensor fault estimator, and the fault estimation of the output voltage sensor is calculated based on the theoretical voltage output value and the output measurement value of the output voltage sensor; the input value of the controller voltage estimation closed loop is calculated based on the fault estimation of the output voltage sensor, the measured output voltage value and the set output voltage reference value; the controller is used to establish the voltage square wave after the error analysis system output is corrected based on the real-time input value of the controller current estimation closed loop and the input value of the controller voltage estimation closed loop.

[0017] From the above, it can be seen that the two time-varying fault estimators of the device can effectively estimate various sensor faults, such as jump faults, offset faults, stuck faults, high-frequency faults and gap faults. Therefore, the fault of the voltage sensor and the measurement distortion of the current sensor can be effectively diagnosed in real time, and comprehensive information on the fault type and fault severity can be obtained based on the calculated data. By correcting the measured values ​​of the voltage and current sensors, the corrected values ​​can effectively approach the measured values ​​of the healthy sensors. Under the action of the stabilization controller, the Boost fault-tolerant converter circuit can effectively track the steady-state capacitor voltage and steady-state inductor current in three cases: i) no sensor fault; ii) single sensor fault; iii) simultaneous distortion of the voltage and current sensors. After the voltage square wave is corrected, the problem that the wrong measurement value sent to the controller will cause duty cycle distortion, thereby causing the voltage and current to deviate from the expected steady-state value can be solved, which can improve the reliability and safety of converter circuits such as Boost converters. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only for the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1The figure is a structural block diagram of a fault diagnosis and correction device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0020] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments.

[0021] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0022] like Figure 1 As shown, a sensor fault diagnosis and correction device on a converter includes an output current sensor, an output voltage sensor, and also includes: an input current sensor, an input voltage sensor, a current sensor fault estimator, a voltage sensor fault estimator and a controller, wherein:

[0023] The output terminal current sensor is used to measure the output terminal current of the converter, and the output terminal voltage sensor is used to measure the output terminal voltage of the converter;

[0024] The input terminal current sensor is used to measure the input terminal current of the converter, and the input terminal voltage sensor is used to measure the input terminal voltage of the converter;

[0025] The current sensor fault estimator is used to calculate a theoretical current output value based on an input measurement value of the input-end current sensor, and to calculate a fault estimate of the output-end current sensor based on the theoretical current output value and the output-end measurement value of the output-end current sensor, and to calculate an input value of a controller current estimation closed loop based on the fault estimate of the output-end current sensor, the measured output current value and the set output current reference value;

[0026] The voltage sensor fault estimator is used to calculate a theoretical voltage output value based on an input measurement value of the input voltage sensor, and to calculate a fault estimation of the output voltage sensor based on the theoretical voltage output value and the output measurement value of the output voltage sensor, and to calculate an input value of a controller voltage estimation closed loop based on the fault estimation of the output voltage sensor, the measured output voltage value and the set output voltage reference value;

[0027] The controller is used to establish a voltage square wave after the error analysis system output is corrected based on the real-time input value of the controller current estimation closed loop and the input value of the controller voltage estimation closed loop.

[0028] The device is arranged on the converter when in use, measures the output current of the converter by the output current sensor, measures the output voltage of the converter by the output voltage sensor, measures the input current of the converter by the input current sensor, measures the input voltage of the converter by the input voltage sensor, calculates the theoretical current output value based on the input measurement value of the input current sensor by the current sensor fault estimator, and obtains the fault estimation of the output current sensor based on the theoretical current output value and the output measurement value of the output current sensor, and calculates the output current value and the set output current value based on the fault estimation of the output current sensor. The current reference value is calculated to obtain the input value of the controller current estimation closed loop; the theoretical voltage output value is calculated based on the input measurement value of the input voltage sensor by the voltage sensor fault estimator, and the fault estimation of the output voltage sensor is calculated based on the theoretical voltage output value and the output measurement value of the output voltage sensor; the input value of the controller voltage estimation closed loop is calculated based on the fault estimation of the output voltage sensor, the measured output voltage value and the set output voltage reference value; the controller is used to establish the voltage square wave after the error analysis system output is corrected based on the real-time input value of the controller current estimation closed loop and the input value of the controller voltage estimation closed loop.

[0029] From the above, it can be seen that the two time-varying fault estimators of the device can effectively estimate various sensor faults, such as jump faults, offset faults, stuck faults, high-frequency faults and gap faults. Therefore, the fault of the voltage sensor and the measurement distortion of the current sensor can be effectively diagnosed in real time, and comprehensive information on the fault type and fault severity can be obtained based on the calculated data. By correcting the measured values ​​of the voltage and current sensors, the corrected values ​​can effectively approach the measured values ​​of the healthy sensors. Under the action of the stabilization controller, the Boost fault-tolerant converter circuit can effectively track the steady-state capacitor voltage and steady-state inductor current in three cases: i) no sensor fault; ii) single sensor fault; iii) simultaneous distortion of the voltage and current sensors. After the voltage square wave is corrected, the problem that the wrong measurement value sent to the controller will cause duty cycle distortion, thereby causing the voltage and current to deviate from the expected steady-state value can be solved, which can improve the reliability and safety of converter circuits such as Boost converters.

[0030] In some embodiments, the output fault estimate of the output current sensor = the measured value of the output current sensor - the theoretical current output value. The input value of the controller current estimation closed loop = (measured output current value - fault estimate of the output current sensor) - the set output current reference value. The output fault estimate of the voltage sensor = the measured value of the output voltage sensor - the theoretical voltage output value. The input value of the controller voltage estimation closed loop = (measured output voltage value - fault estimate of the output voltage sensor) - the set output voltage reference value.

[0031] The present invention designs a time-varying fault estimator for voltage sensor fault and current sensor fault respectively, automatically updates the parameters of the time-varying estimator, estimates the voltage sensor fault and current sensor distortion respectively, thereby realizing real-time monitoring and diagnosis of the voltage sensor and current sensor.

[0032] In some embodiments, the device further comprises a limiter, which is configured to receive the modified voltage square wave and adjust the amplitude of the modified voltage square wave to a predetermined value.

[0033] By controlling the amplitude of the voltage square wave through a limiter, damage to the converter caused by excessively high amplitude values ​​can be avoided.

[0034] In some embodiments, the device further comprises a pulse width modulator for adjusting the pulse width of the modified voltage square wave.

[0035] It should be understood by those skilled in the art that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present invention (including the claims) is limited to these examples. Within the scope of the present invention, the technical features in the above embodiments or in different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the above aspects of the present invention, which are not provided in detail for the sake of simplicity.

[0036] The present invention is intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A sensor fault diagnosis and correction device for a converter, comprising an output current sensor and an output voltage sensor, characterized in that: Also includes: An input-end current sensor, an input-end voltage sensor, a current sensor fault estimator, a voltage sensor fault estimator, and a controller, wherein: The output terminal current sensor is used to measure the output terminal current of the converter, and the output terminal voltage sensor is used to measure the output terminal voltage of the converter; The input terminal current sensor is used to measure the input terminal current of the converter, and the input terminal voltage sensor is used to measure the input terminal voltage of the converter; The current sensor fault estimator is used to calculate a theoretical current output value based on an input measurement value of the input-end current sensor, and to calculate a fault estimate of the output-end current sensor based on the theoretical current output value and the output-end measurement value of the output-end current sensor, and to calculate an input value of a controller current estimation closed loop based on the fault estimate of the output-end current sensor, the measured output current value and the set output current reference value; The voltage sensor fault estimator is used to calculate a theoretical voltage output value based on an input measurement value of the input voltage sensor, and to calculate a fault estimation of the output voltage sensor based on the theoretical voltage output value and the output measurement value of the output voltage sensor, and to calculate an input value of a controller voltage estimation closed loop based on the fault estimation of the output voltage sensor, the measured output voltage value and the set output voltage reference value; The controller is used to establish a voltage square wave after the error analysis system output is corrected based on the real-time input value of the controller current estimation closed loop and the input value of the controller voltage estimation closed loop.

2. A sensor fault diagnosis and correction device for a converter according to claim 1, characterized in that: The output fault estimation of the output end current sensor=the measured value of the output end current sensor−the theoretical current output value.

3. A sensor fault diagnosis and correction device for a converter according to claim 1, characterized in that: The input value of the controller current estimation closed loop=(measured output current value-fault estimation of the output current sensor)-set output current reference value.

4. A sensor fault diagnosis and correction device for a converter according to claim 1, characterized in that: The output fault estimation of the voltage sensor=the measured value of the output voltage sensor-theoretical voltage output value.

5. The device for diagnosing and correcting sensor faults on a converter according to claim 1, characterized in that: The controller voltage estimation closed-loop input value=(measured output voltage value-fault estimation of the output voltage sensor)-set output voltage reference value.

6. The device for diagnosing and correcting sensor faults on a converter according to claim 1, characterized in that: The device further comprises a limiter, which is used for receiving the modified voltage square wave and adjusting the amplitude of the modified voltage square wave to a predetermined value.

7. The device for diagnosing and correcting sensor faults on a converter according to claim 1, characterized in that: The device further comprises a pulse width modulator, which is used to adjust the pulse width of the modified voltage square wave.