One-way current detection method of power tube

Abstract

The invention relates to the technical field of current signal processing, and discloses a one-way current detection method of a power tube, which comprises the following steps of: processing a power signal through a power detection part and a common-mode signal extraction unit respectively to obtain a power detection signal and a common-mode detection signal, and performing bias voltage superposition on the power detection signal and the common-mode detection signal respectively to obtain a one-way current detection signal of the power tube; according to the technical scheme, a first detection signal and a second detection signal are obtained, a first signal processing module and a second signal processing module are used for processing the first detection signal and the second detection signal respectively, and a voltage feedback signal having a fixed proportional relation with a one-way current signal is obtained. The common-mode noise is effectively suppressed, the reliability of signal processing is enhanced, accurate control is realized through voltage feedback of a fixed proportional relation, and the problem that the cost is high when an external resistor is adopted for detecting a circuit in the prior art is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of current signal processing, and in particular to a unidirectional current detection method for a power tube. Background Art

[0002] In the field of power electronics, accurate current detection and control are crucial to the performance and safe operation of equipment. In the existing technology, the current detection of motors generally adopts the external resistor method. Other similar on-chip detection is not easy to make corresponding detection output. The external resistor method has a corresponding high application cost. Other detections can only perform overcurrent protection due to insufficient accuracy and are not easy to give a flag output. Summary of the invention

[0003] The object of the present invention is to provide a unidirectional current detection method for a power tube, aiming to solve the problem of high cost of using an external resistor to detect the circuit in the prior art.

[0004] The present invention is implemented in this way. In a first aspect, the present invention provides a unidirectional current detection method for a power tube, comprising: Acquire a unidirectional current signal of the power tube, and respectively perform signal processing on the unidirectional current signal through a power detection part and a common mode signal extraction unit electrically connected to the power tube to obtain a power detection signal and a common mode detection signal; Superimposing bias voltages on the power detection signal and the common mode detection signal to obtain a first detection signal and a second detection signal; The first detection signal and the second detection signal are processed by a first signal processing module electrically connected to the power detection part and a second signal processing module electrically connected to the common-mode signal extraction unit to obtain a voltage feedback signal; wherein the voltage feedback signal has a fixed proportional relationship with the unidirectional current signal.

[0005] The present invention provides a unidirectional current detection method for a power tube, which has the following beneficial effects: The present invention processes the power signal through a power detection part and a common-mode signal extraction unit respectively to obtain a power detection signal and a common-mode detection signal, and performs bias voltage superposition on the power detection signal and the common-mode detection signal respectively to obtain a first detection signal and a second detection signal, and uses a first signal processing module and a second signal processing module to process the first detection signal and the second detection signal respectively to obtain a voltage feedback signal with a fixed proportional relationship with the unidirectional current signal. The technical solution improves the accuracy and stability of current detection, effectively suppresses common-mode noise, and enhances the reliability of signal processing. Precise control is achieved through voltage feedback with a fixed proportional relationship, which solves the problem of high cost of using external resistors to detect circuits in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 It is a schematic diagram of the steps of a unidirectional current detection method of a power tube provided by an embodiment of the present invention; Figure 2 The present invention is a schematic diagram of a circuit structure used in a method for detecting a unidirectional current of a power tube provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0007] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0008] The implementation of the present invention is described in detail below in conjunction with specific embodiments.

[0009] Reference Figure 1 , Figure 2 As shown, a preferred embodiment of the present invention is provided.

[0010] In a first aspect, the present invention provides a unidirectional current detection method for a power tube, comprising: S1: obtaining a unidirectional current signal of the power tube, and performing signal processing on the unidirectional current signal through a power detection part and a common mode signal extraction unit electrically connected to the power tube, so as to obtain a power detection signal and a common mode detection signal; S2: Superimposing bias voltages on the power detection signal and the common mode detection signal to obtain a first detection signal and a second detection signal; S3: Performing signal processing on the first detection signal and the second detection signal through a first signal processing module electrically connected to the power detection part and a second signal processing module electrically connected to the common-mode signal extraction unit to obtain a voltage feedback signal; wherein the voltage feedback signal has a fixed proportional relationship with the unidirectional current signal.

[0011] Specifically, in step S1 of the embodiment provided by the present invention, a unidirectional current signal is obtained from the power tube. The current signal is obtained by electrically connecting the detection circuit to the target power tube, thereby introducing the unidirectional current signal of the power tube.

[0012] It should be noted that a unidirectional current signal means that the current flows in only one direction (for example, from the power supply to the load). This signal can be direct current (DC) or alternating current (AC) but has a single directionality.

[0013] More specifically, the acquired unidirectional current signal is sent to two different circuit units respectively. The power detection part is specifically used to process the effective component in the current signal and extract the useful detection signal. The common mode signal extraction unit is used to extract the common mode component in the current signal for subsequent compensation or correction.

[0014] More specifically, the signal processing of the power detection part may include signal processing operations such as filtering, amplification, and rectification to extract the effective component representing the current signal to obtain a power detection signal, which reflects the effective value or characteristics of the current.

[0015] More specifically, the common-mode signal extraction unit processing focuses on extracting common-mode components in the current signal, which are usually noise or interference. The common-mode detection signal contains the common-mode noise or interference components in the current signal.

[0016] It can be understood that by extracting the effective signal and the common-mode signal respectively, the useful signal and noise can be effectively separated, and the quality and accuracy of the signal can be improved. The common-mode signal extraction unit can detect and identify common-mode noise, providing a basis for subsequent noise suppression. The power detection signal obtained by the power detection part can accurately reflect the actual situation of the current signal and improve the measurement accuracy. The common-mode detection signal obtained by the common-mode signal extraction unit can be used for subsequent signal correction and compensation, further improving the accuracy of signal processing.

[0017] Specifically, in step S2 of the embodiment provided by the present invention, the power detection signal obtained from S1 represents the effective component of the current signal, and the common mode detection signal obtained from S1 represents the common mode noise or interference component in the current signal.

[0018] More specifically, an appropriate bias voltage is generated by a precision voltage source or an adjustable resistor network to ensure the stability and accuracy of the bias voltage. The bias voltage is superimposed on the power detection signal. The bias voltage and the power detection signal are superimposed to form a first detection signal. This step can be achieved by an operational amplifier or an adding circuit. The bias voltage is superimposed on the common-mode detection signal. The bias voltage and the common-mode detection signal are superimposed to form a second detection signal. This step can also be achieved by an operational amplifier or an adding circuit.

[0019] More specifically, the first detection signal is a signal processed by bias voltage superposition, including a power detection signal and a bias voltage, and the signal is processed by bias voltage superposition, including a common mode detection signal and a bias voltage.

[0020] It can be understood that by superimposing an appropriate bias voltage, the reference level of the signal can be effectively adjusted, making subsequent signal processing more accurate and stable. The superposition of bias voltage helps to adjust the signal to a suitable operating range and avoid signal distortion or noise interference at low levels. The detection signal after bias voltage processing has higher stability, reducing the impact of environmental changes or power supply fluctuations, providing a stable and reliable input signal for subsequent signal processing units, and helping to improve the stability and reliability of the entire system.

[0021] It can be seen that the key to this step is to obtain the power detection signal and common mode detection signal obtained from step S1, and superimpose appropriate bias voltages to form the first detection signal and the second detection signal. This processing method can effectively adjust the reference level of the signal, improve the accuracy and stability of signal processing, expand the dynamic range of the signal, and provide a more stable and reliable input signal for subsequent signal processing. This provides an important guarantee for improving the overall performance of the system and optimizing the signal processing effect.

[0022] Specifically, in step S3 of the embodiment provided by the present invention, the first detection signal obtained from step S2 is input into the first signal processing module, and the second detection signal obtained from step S2 is input into the second signal processing module.

[0023] More specifically, the first detection signal is filtered to remove high-frequency noise and unnecessary interference components, the filtered signal is amplified to enhance the signal strength and ensure the signal availability, and the amplified analog signal is converted into a voltage signal suitable for subsequent processing.

[0024] More specifically, the second detection signal is filtered to remove high-frequency noise and unnecessary interference components, the filtered signal is amplified to enhance the signal strength, and the amplified analog signal is converted into a voltage signal suitable for subsequent processing.

[0025] More specifically, the signals output by the first signal processing module and the second signal processing module are combined to obtain a comprehensive voltage signal. According to the system design requirements, the combined voltage signal is adjusted so that it has a fixed proportional relationship with the unidirectional current signal. This can be achieved by adjusting the gain, scaling, etc.

[0026] More specifically, the adjusted signal is output as a voltage feedback signal, which maintains a fixed proportional relationship with the unidirectional current signal. The generated voltage feedback signal can be subsequently fed back to the control unit or other related modules of the system for further control and regulation.

[0027] It can be understood that through filtering, amplification and conversion processing, the accuracy of the signal can be effectively improved and the impact of noise and interference on the signal can be reduced. The processed signal has higher stability, which helps to stabilize the operation of the system. The fixed-ratio feedback signal provides a reliable feedback mechanism, allowing the system to adjust and optimize its own performance in a timely manner.

[0028] See also Figure 2 Transistor Q5 is the sense tube of the power tube Q1. In order to make the detection op amp work in the appropriate area, a suitable voltage Voffset is superimposed on the input. This additional error will be included in the common-mode current and subtracted. The final output is a voltage based on the zero level and is fixedly proportional to the Q1 current.

[0029] The present invention provides a unidirectional current detection method for a power tube, which has the following beneficial effects: The present invention processes the power signal through a power detection part and a common-mode signal extraction unit respectively to obtain a power detection signal and a common-mode detection signal, and performs bias voltage superposition on the power detection signal and the common-mode detection signal respectively to obtain a first detection signal and a second detection signal, and uses a first signal processing module and a second signal processing module to process the first detection signal and the second detection signal respectively to obtain a voltage feedback signal with a fixed proportional relationship with the unidirectional current signal. The technical solution improves the accuracy and stability of current detection, effectively suppresses common-mode noise, and enhances the reliability of signal processing. Precise control is achieved through voltage feedback with a fixed proportional relationship, which solves the problem of high cost of using external resistors to detect circuits in the prior art.

[0030] It can be seen that the technical solution of the present invention has a reasonably corresponding common-mode bias structure, realizes current-type conversion output, and has a common-mode current regulation structure. Its progress lies in: it can achieve high linearity in both low and high current detection, has extremely low sensitivity to temperature and overall deviation, can be flexibly adjusted for various adaptation deviations, and the detection output method can be flexibly applied to other applications.

[0031] Preferably, the step of respectively superimposing and inputting bias voltages on the power detection signal and the common mode detection signal to obtain the first detection signal and the second detection signal comprises: S21: superimposing a bias voltage on the power detection signal through a first voltage source V1 pre-set between the power detection part and the first signal processing module to obtain a first detection signal; wherein the first voltage source V1 is used to provide a bias voltage to the power detection signal for bias compensation, so that the power detection signal is in a signal region suitable for the detection op amp to work; S22: A second detection signal is obtained by superimposing a bias voltage on the common-mode detection signal through a second voltage source V2 pre-set between the common-mode signal extraction unit and the second signal processing module; wherein the second voltage source V2 is used to provide a bias voltage to the common-mode detection signal for bias compensation, so that the common-mode detection signal is in a signal region suitable for the detection operational amplifier to operate.

[0032] Specifically, the first voltage source V1 is pre-set between the power detection part and the first signal processing module, and the first voltage source V1 is configured to ensure that it can provide an appropriate bias voltage. The power detection signal passes through the first voltage source V1 and is superimposed with a preset bias voltage. By superimposing the bias voltage, the power detection signal is adjusted to a signal area suitable for the detection op amp to work. The signal after the bias voltage adjustment is input into the first signal processing module as the first detection signal.

[0033] More specifically, the second voltage source V2 is pre-set between the common-mode signal extraction unit and the second signal processing module, and the second voltage source V2 is configured to ensure that it can provide an appropriate bias voltage. The common-mode detection signal passes through the second voltage source V2 and is superimposed with a preset bias voltage. By superimposing the bias voltage, the common-mode detection signal is adjusted to a signal area suitable for the detection op amp to work, and the signal after the bias voltage adjustment is input into the second signal processing module as the second detection signal.

[0034] It can be understood that by superimposing the bias voltages on the power detection signal and the common-mode detection signal respectively, it can ensure that both signals are in a signal area suitable for the detection op amp to work, which is crucial for subsequent signal processing and can improve the accuracy and stability of signal processing. Through bias compensation, the signal offset can be effectively eliminated, making the signal reference position more stable and reducing the error caused by signal offset.

[0035] Preferably, the step of performing signal processing on the first detection signal and the second detection signal through a first signal processing module electrically connected to the power detection part and a second signal processing module electrically connected to the common mode signal extraction unit to obtain a voltage feedback signal includes: S31: performing signal processing on a first detection signal through a first signal processing module electrically connected to the power detection part to obtain a first feedback signal; S32: performing signal processing on the second detection signal through a second signal processing module electrically connected to the common mode signal extraction unit to obtain a second feedback signal; S33: The first signal processing module is electrically connected to the second signal processing module to perform signal synthesis processing on the first feedback signal and the second feedback signal, so that the second feedback signal suppresses the bias voltage of the first feedback signal, thereby obtaining a voltage feedback signal.

[0036] Specifically, the first signal processing module receives the first detection signal from the power detection part, performs amplification processing to improve the signal strength, removes high-frequency noise and interference in the signal through a filter to ensure the purity of the signal, shapes the signal to make the signal waveform more regular and stable, and converts the analog signal into a digital signal to facilitate subsequent digital signal processing.

[0037] More specifically, the second detection signal is processed by a second signal processing module electrically connected to the common-mode signal extraction unit to obtain a second feedback signal. The second signal processing module receives the second detection signal from the common-mode signal extraction unit, extracts the common-mode signal component therein, applies common-mode noise suppression technology to filter out common-mode noise, improves the signal-to-noise ratio of the signal, amplifies the processed signal to ensure sufficient signal strength, and converts the processed signal from analog form to digital form for subsequent processing.

[0038] More specifically, the first signal processing module is electrically connected to the second signal processing module, and the first feedback signal and the second feedback signal are subjected to signal synthesis processing, so that the second feedback signal suppresses the bias voltage of the first feedback signal, thereby obtaining a voltage feedback signal. The first feedback signal and the second feedback signal are synthesized, usually by a superposition or weighted averaging method, and the common mode information in the second feedback signal is used to suppress the bias voltage in the first feedback signal to reduce the bias error. The processed synthesized signal is output as a voltage feedback signal and provided to a subsequent control system for use.

[0039] It can be understood that through the separate processing and synthesis of the first signal processing module and the second signal processing module, the bias voltage can be effectively extracted and suppressed, and the accuracy of the feedback signal can be improved. Through the common-mode signal extraction and noise suppression technology, the common-mode noise in the feedback signal can be significantly reduced, and the purity of the signal can be improved. The stable and reliable voltage feedback signal helps to accurately adjust the control system and improve the stability and response speed of the entire system.

[0040] Preferably, the first signal processing module and the second signal processing module each include a detection signal amplifying part, a detection signal current converting part and a current synthesizing unit.

[0041] Specifically, the first signal processing module and the second signal processing module have the same components, and the first signal processing module and the second signal processing module perform the same processing effect.

[0042] Preferably, the step of performing signal processing on the first detection signal by a first signal processing module electrically connected to the power detection part to obtain a first feedback signal comprises: S311: performing signal amplification processing on the first detection signal by the detection signal amplification part to obtain a first amplified signal; S312: performing current conversion processing on the first amplified signal through the detection signal current conversion part to obtain a first feedback signal, so that the current synthesis unit can perform signal synthesis processing on the first feedback signal and the second feedback signal.

[0043] Specifically, the first signal processing module receives the first detection signal from the power detection part, first amplifies the signal through the detection signal amplification part to enhance the signal strength, and the amplified first detection signal is sent to the detection signal current conversion part to convert the voltage signal into a current signal for subsequent processing. The current signal is synthesized with other processing signals through the current synthesis unit to obtain a first feedback signal.

[0044] Preferably, the step of performing signal processing on the second detection signal by a second signal processing module electrically connected to the common mode signal extraction unit to obtain a second feedback signal comprises: S321: performing signal amplification processing on the second detection signal by the detection signal amplifying part to obtain a second amplified signal; S322: performing current conversion processing on the second amplified signal through the detection signal current conversion part to obtain a second feedback signal, so that the current synthesis unit can perform signal synthesis processing on the second feedback signal and the first feedback signal.

[0045] Specifically, the second signal processing module receives the second detection signal from the common-mode signal extraction unit, first amplifies the signal through the detection signal amplification part to enhance the signal strength, and the amplified second detection signal is sent to the detection signal current conversion part to convert the voltage signal into a current signal for subsequent processing. The current signal is synthesized with other processing signals through the current synthesis unit to obtain a second feedback signal.

[0046] More specifically, the current synthesis unit of the first signal processing module synthesizes the first feedback signal with the second feedback signal output by the current synthesis unit of the second signal processing module. Through the synthesis process, the bias voltage in the first feedback signal is suppressed by utilizing the common mode information in the second feedback signal to reduce the bias error. The synthesized current signal is converted back into a voltage signal, and finally a stable voltage feedback signal is output for use by the subsequent control system.

[0047] Preferably, the power detection part includes a power tube Q1, a transistor Q2 and a transistor Q3; the power tube Q1 is used to inject a unidirectional current signal, and the power tube Q1 is grounded; the transistor Q2 and the transistor Q3 are respectively electrically connected to the power tube Q1 in series, and the transistor Q2 and the transistor Q3 are in parallel and electrically connected to the first signal processing module; the common-mode signal extraction unit includes a transistor Q9, and the transistor Q9 is electrically connected to the power tube Q1.

[0048] Specifically, the power tube Q1 is used to inject a unidirectional current signal and is grounded, the transistor Q2 is connected in series with Q1, the transistor Q3 is connected in series with Q1, and Q2 and Q3 are in parallel.

[0049] More specifically, the Power tube Q1 injects a unidirectional current signal to ensure the directionality and stability of the signal, while the grounding provides a stable reference potential. Transistors Q2 and Q3 are connected in series with Q1, and Q2 and Q3 are connected in parallel to form a signal processing channel for regulating and amplifying the current signal. The parallel structure of Q2 and Q3 can achieve signal diversion and redundancy, ensuring the reliability and stability of signal processing.

[0050] More specifically, the components of the common-mode signal extraction unit are transistor Q9, which is electrically connected to the Power tube Q1. Transistor Q9 is responsible for extracting the common-mode signal. Through the connection with Q1, it can effectively obtain the common-mode noise and interference signals in the system, and provide the necessary common-mode information for the subsequent signal processing module.

[0051] More specifically, the Power tube Q1 injects a unidirectional current signal and is grounded to form a stable current path. The injected current signal is processed by transistors Q2 and Q3 connected in series. Q2 and Q3 are connected in parallel to ensure signal stability and shunt processing.

[0052] More specifically, transistor Q9 is electrically connected to the Power tube Q1. Through this connection, Q9 can extract the common-mode signal in the system from Q1 and provide common-mode information.

[0053] More specifically, the first signal processing module receives a signal from the Power detection part, and generates a first feedback signal after being processed by the detection signal amplification part, the detection signal current conversion part and the current synthesis unit. The detection signal amplification part enhances the signal, the current conversion part converts the voltage signal into a current signal, and the current synthesis unit performs synthesis processing on the signal.

[0054] More specifically, the second signal processing module receives the signal from the common-mode signal extraction unit (through transistor Q9), and generates a second feedback signal through a similar processing process. The detection signal amplification part enhances the common-mode signal, the current conversion part converts the voltage signal into a current signal, and the current synthesis unit performs synthesis processing on the signal.

[0055] More specifically, the output signals of the first signal processing module and the second signal processing module are synthesized. During the synthesis process, the common mode information in the second feedback signal is used to suppress the bias voltage in the first feedback signal to reduce the bias error. Finally, the synthesized signal is converted back into a voltage signal to output a stable voltage feedback signal.

[0056] It can be understood that the accuracy of signal processing is effectively improved by detecting signal amplification and current conversion. The introduction of the common-mode signal extraction unit significantly reduces the noise interference in the system. Through the processing of the current synthesis unit, the bias voltage is suppressed, the system error is reduced, and a stable and accurate voltage feedback signal is generated, thereby improving the stability and response speed of the control system.

[0057] Preferably, the detection signal amplification part is an operational amplifier circuit composed of an operational amplifier △1, a resistor R1 and a resistor R2, and the detection signal current conversion part includes an operational amplifier △2, a transistor Q4 and a transistor Q5; the input end of the operational amplifier △2 is electrically connected to the transistor Q4, the positive input end of the operational amplifier △2 is electrically connected to the output end of the operational amplifier △1, and the inverting input end of the operational amplifier △2 is electrically connected to the transistor Q5; the transistor Q5 of the first signal processing module is electrically connected to the transistor Q5 of the second signal processing module; the current synthesis unit includes a transistor Q7 and a transistor Q8; the transistor Q7 of the first signal processing module is electrically connected to the transistor Q8 of the second signal processing module; the transistor Q8 of the first signal processing module is electrically connected to an external resistor and then grounded.

[0058] Specifically, operational amplifier △1 is a core amplifier device, resistors R1 and R2 form an operational amplifier circuit with △1, and the circuit composed of operational amplifier △1, resistors R1 and R2 is used to amplify the detection signal to ensure the strength and quality of the signal in subsequent processing.

[0059] More specifically, the components of the detection signal current conversion part include an operational amplifier Δ2 for current conversion, a transistor Q4 connected to the input terminal of Δ2, and a transistor Q5 connected to the inverting input terminal of Δ2.

[0060] More specifically, the input terminal of operational amplifier △2 is electrically connected to transistor Q4, the positive input terminal is electrically connected to the output terminal of operational amplifier △1, and the inverting input terminal is electrically connected to transistor Q5. This structure is used to convert the amplified voltage signal into a current signal for subsequent processing.

[0061] More specifically, the components of the current synthesis unit include transistor Q7 and transistor Q8, and transistors Q7 and Q8 constitute the current synthesis unit for synthesizing the current signals from the first and second signal processing modules and converting the synthesized signals back into voltage signals.

[0062] More specifically, the input detection signal is first amplified by operational amplifier △1, and resistors R1 and R2 provide necessary filtering and stabilization functions during the amplification process. The amplified signal is transmitted to △2 through the positive input terminal of operational amplifier △2. The input terminal of △2 is electrically connected to transistor Q4, and the inverting input terminal is electrically connected to transistor Q5. The voltage signal is converted into a current signal through operational amplifier △2.

[0063] More specifically, transistor Q5 of the first signal processing module and the second signal processing module are electrically connected to ensure coordinated signal processing of the two modules. The current signal is synthesized through transistors Q7 and Q8. Q8 is electrically connected to an external resistor and then grounded to form a complete signal processing loop. The synthesized current signal is converted back into a voltage signal through transistors Q7 and Q8, and a stable voltage feedback signal is output to achieve precise control and feedback.

[0064] It can be understood that the combination of the operational amplifier and the resistor ensures the high precision and stability of signal amplification. The process of converting the voltage signal into the current signal is precisely controlled to ensure the accurate transmission of the signal. Through common-mode signal extraction and processing, the common-mode noise and interference in the system are effectively suppressed to improve the signal quality. The current synthesis unit synthesizes the current signals from different signal processing modules through the coordinated work of transistors Q7 and Q8. The final output voltage signal is synthesized and processed to suppress the bias voltage and achieve high-precision voltage feedback.

[0065] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A unidirectional current detection method for a power tube, characterized in that: include: Acquire a unidirectional current signal of the power tube, and respectively perform signal processing on the unidirectional current signal through a power detection part and a common mode signal extraction unit electrically connected to the power tube to obtain a power detection signal and a common mode detection signal; Superimposing bias voltages on the power detection signal and the common mode detection signal to obtain a first detection signal and a second detection signal; The first detection signal and the second detection signal are processed by a first signal processing module electrically connected to the power detection part and a second signal processing module electrically connected to the common-mode signal extraction unit to obtain a voltage feedback signal; wherein the voltage feedback signal has a fixed proportional relationship with the unidirectional current signal.

2. A unidirectional current detection method for a power tube as claimed in claim 1, characterized in that: The steps of respectively superimposing and inputting bias voltages on the power detection signal and the common mode detection signal to obtain a first detection signal and a second detection signal include: A first detection signal is obtained by superimposing a bias voltage on the power detection signal through a first voltage source V1 pre-set between the power detection part and the first signal processing module; wherein the first voltage source V1 is used to provide a bias voltage to the power detection signal for bias compensation, so that the power detection signal is in a signal region suitable for the detection op amp to work; By pre-setting a second voltage source V2 between the common-mode signal extraction unit and the second signal processing module, a bias voltage is superimposed and inputted to the common-mode detection signal to obtain a second detection signal; wherein the second voltage source V2 is used to provide a bias voltage to the common-mode detection signal for bias compensation, so that the common-mode detection signal is in a signal region suitable for the operation of the detection operational amplifier.

3. A unidirectional current detection method for a power tube as claimed in claim 1, characterized in that: The step of performing signal processing on the first detection signal and the second detection signal to obtain a voltage feedback signal by using a first signal processing module electrically connected to the power detection part and a second signal processing module electrically connected to the common mode signal extraction unit includes: Processing the first detection signal by a first signal processing module electrically connected to the power detection part to obtain a first feedback signal; Processing the second detection signal by a second signal processing module electrically connected to the common mode signal extraction unit to obtain a second feedback signal; The first signal processing module is electrically connected to the second signal processing module to perform signal synthesis processing on the first feedback signal and the second feedback signal, so that the second feedback signal suppresses the bias voltage of the first feedback signal, thereby obtaining a voltage feedback signal.

4. A unidirectional current detection method for a power tube as claimed in claim 3, characterized in that: The first signal processing module and the second signal processing module each include a detection signal amplifying portion, a detection signal current converting portion and a current synthesizing unit.

5. A method for detecting unidirectional current of a power tube as claimed in claim 4, characterized in that: The step of performing signal processing on the first detection signal by a first signal processing module electrically connected to the power detection part to obtain a first feedback signal comprises: Performing signal amplification processing on the first detection signal by the detection signal amplification part to obtain a first amplified signal; The first amplified signal is subjected to current conversion processing by the detection signal current conversion part to obtain a first feedback signal, so that the current synthesis unit can perform signal synthesis processing on the first feedback signal and the second feedback signal.

6. A method for detecting unidirectional current of a power tube as claimed in claim 4, characterized in that: The step of performing signal processing on the second detection signal by a second signal processing module electrically connected to the common mode signal extraction unit to obtain a second feedback signal comprises: Performing signal amplification processing on the second detection signal by the detection signal amplification part to obtain a second amplified signal; The second amplified signal is subjected to current conversion processing by the detection signal current conversion part to obtain a second feedback signal, so that the current synthesis unit can synthesize the second feedback signal with the first feedback signal.

7. A method for detecting unidirectional current of a power tube according to claim 1, characterized in that: The power detection part includes a power tube Q1, a transistor Q2 and a transistor Q3; The power tube Q1 is used to inject a unidirectional current signal, and the power tube Q1 is grounded; The transistor Q2 and the transistor Q3 are electrically connected to the power tube Q1 in series, respectively, and the transistor Q2 and the transistor Q3 are electrically connected to the first signal processing module in parallel; The common-mode signal extraction unit includes a transistor Q9, and the transistor Q9 is electrically connected to the power tube Q1.

8. A method for detecting unidirectional current of a power tube as claimed in claim 4, characterized in that: The detection signal amplification part is an operational amplifier circuit composed of an operational amplifier △1, a resistor R1 and a resistor R2, and the detection signal current conversion part includes an operational amplifier △2, a transistor Q4 and a transistor Q5; The input terminal of the operational amplifier △2 is electrically connected to the transistor Q4, the positive input terminal of the operational amplifier △2 is electrically connected to the output terminal of the operational amplifier △1, and the inverting input terminal of the operational amplifier △2 is electrically connected to the transistor Q5; The transistor Q5 of the first signal processing module is electrically connected to the transistor Q5 of the second signal processing module; The current synthesis unit includes a transistor Q7 and a transistor Q8; The transistor Q7 of the first signal processing module is electrically connected to the transistor Q8 of the second signal processing module; The transistor Q8 of the first signal processing module is electrically connected to an external resistor and then grounded.

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