A high load wideband high current power amplifier and method for testing of a traveling wave distance measuring device

Abstract

The application discloses a kind of high-load wide frequency band large current power amplifier and method for travelling wave distance measuring device test, belong to electric power system test field.The amplifier includes signal conditioning, error amplification, drive, power amplification, current feedback, power supply and output module;Signal conditioning module pre-processes input signal, error amplification module generates error drive signal in conjunction with double feedback, drive module bridge type amplifies signal, power amplification module realizes large current output with multiple MOS parallel connection, current feedback module acquires and processes load current, power supply module is multistage isolation architecture, and output module integrates safety protection.The method is by signal conditioning, error amplification, signal drive, power amplification, current feedback, power supply and safety output steps, and injects 100A peak value, DC to 500kHz wide frequency band fault current travelling wave signal to travelling wave distance measuring complete device.The application realizes high load, wide frequency band, large current and high fidelity output, improves travelling wave distance measuring device test accuracy and reliability.

Description

Technical Field

[0001] This invention belongs to the field of power system testing technology, specifically relating to a high-load, wideband, high-current power amplifier and method for testing traveling wave ranging devices. It is particularly suitable for simulating the injection of high-peak-value, wideband fault current traveling wave signals into the primary side of a traveling wave ranging system to accurately test and verify the device's performance. Background Technology

[0002] Traveling wave ranging is a key technology for accurate fault location in power systems. Currently, the mainstream technology on the market uses a two-terminal current traveling wave location method. Its principle is to calculate the fault location by detecting the time difference between the arrival times of the transient current traveling wave signal generated at the moment of a power line fault at both ends of the line. The accuracy and reliability of this technology are highly dependent on the performance of the traveling wave ranging system. Therefore, in testing and verification, the power amplifier needs to be able to accurately reproduce the fault traveling wave signal containing rich high-frequency components. This fault signal must have strong load-carrying capacity, a wide frequency range, a large current amplitude, and extremely high requirements for waveform fidelity and transient response speed.

[0003] Currently available general-purpose power amplifiers, due to performance limitations, are unable to meet all the requirements for fault signal simulation.

[0004] 1) Traditional linear power amplifiers: These amplifiers have the advantages of low distortion and high fidelity, but their usual application is the output of 50Hz signals in power systems. Their bandwidth can be extended to the tens of kHz level at most according to the harmonic output requirements, which is difficult to reach the 500kHz level required for traveling wave testing.

[0005] 2) Class D and other switching amplifiers: These amplifiers are highly efficient, but the switching mode results in high noise and severe electromagnetic interference. The output filtering stage introduces phase delay and signal distortion, which cannot meet the requirements for accurate high-frequency reproduction.

[0006] 3) Existing high-frequency amplifiers: Most are designed for small signals or low power, and their output current and power capacity are insufficient to drive the high impedance load in the ranging test of the traveling wave complete set of equipment, and cannot simulate the real working conditions of primary side signal injection.

[0007] In summary, existing technologies lack a power amplifier solution that can simultaneously address the technical challenges of high load drive capability, wide bandwidth response, high current output, and high signal fidelity. This technological gap severely restricts the accuracy and reliability of testing and verification of traveling wave ranging devices. Therefore, there is an urgent need for an innovative power amplification method and system to fill this technological gap. Summary of the Invention

[0008] This invention aims to address the shortcomings of existing technologies by providing a high-load, wideband, high-current power amplifier and method for testing traveling wave ranging devices. The core technical problem it addresses is how to simultaneously achieve high load drive capability, wideband response, high current output, and extremely high signal fidelity in a power amplifier. This overcomes the limitations of traditional linear amplifiers (insufficient bandwidth), switching amplifiers (high noise and distortion), and existing high-frequency amplifiers (weak load-carrying capacity), thereby meeting the stringent requirements for accurate testing and verification of traveling wave ranging systems.

[0009] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0010] A high-load, wide-bandwidth, high-current power amplifier for testing traveling wave ranging devices includes a signal conditioning module, an error amplification module, a drive module, a power amplification module, a current feedback module, a power supply module, and an output module.

[0011] The signal conditioning module is used to receive and preprocess external input signals;

[0012] The error amplification module receives the preprocessed signal and feedback signal output by the signal conditioning module, and generates an error driving signal by comparing and amplifying the signal. The feedback signal includes at least a differential feedback signal and a current sampling feedback signal.

[0013] The driving module receives the error driving signal output by the error amplification module, amplifies the signal, and then transmits it to the power amplification module.

[0014] The power amplifier module adopts a parallel structure of multiple power devices to convert the signal output by the drive module into a high current signal;

[0015] The current feedback module collects the load current output by the power amplifier module, processes it to generate the current sampling feedback signal, and sends it back to the error amplifier module.

[0016] The power module is a multi-level isolated power architecture, providing adaptive power to each module of the amplifier.

[0017] The output module is used to output high current signals and integrates a safety protection unit.

[0018] Preferably, the signal conditioning module adopts a differential structure and integrates a zero-point adjustment unit and a gain fine-tuning unit; the differential structure has high input impedance and high common-mode rejection ratio; the zero-point adjustment unit is used to eliminate signal DC bias and module self-offset voltage; and the gain fine-tuning unit is used to adjust the input signal to a level suitable for the power amplifier module.

[0019] Preferably, the differential feedback signal of the error amplification module is generated by a voltage divider circuit consisting of a capacitor and a first resistor connected in series, and then a second resistor. The voltage divider circuit is connected to the inverting input port of the operational amplifier of the error amplification module. The current sampling feedback signal is 180° out of phase with the preprocessed signal and is connected to the non-inverting input port of the operational amplifier.

[0020] Preferably, the driving module consists of two high-voltage operational amplifiers forming a bridge driving structure. The upper-level signal is connected to the non-inverting input and the inverting input of the two high-voltage operational amplifiers respectively. The voltage amplification factor of a single high-voltage operational amplifier is 2 times, and the overall voltage amplification factor after bridge output is 4 times. The output terminal of one of the high-voltage operational amplifiers shares a common ground with the power amplification module.

[0021] Preferably, the power device of the power amplifier module is a MOSFET with low gate charge and low junction capacitance, and the gate of the MOSFET is connected in series with a gate resistor with a resistance of 51 ohms.

[0022] Preferably, the current feedback module includes a current sampling unit and a common-mode rejection amplifier unit; the current sampling unit includes a high-precision, low-temperature drift sampling resistor and an operational amplifier, the sampling resistor is connected in series between the power amplifier module and the load, the operational amplifier is powered by an isolated power supply, and the power supply ground of the operational amplifier and the high-side ground of the sampling resistor are common ground, forming a floating sampling system; the common-mode rejection amplifier unit consists of a high-voltage operational amplifier and four precision matching resistors forming a differential amplifier structure.

[0023] Preferably, the multi-stage isolated power supply of the power module includes a ±54V high-power power supply, a ±36V pre-stage drive power supply, a ±15V system control power supply, and a ±15V current sampling isolated power supply; the ±54V high-power power supply powers the power amplifier module, the ±36V pre-stage drive power supply powers the drive module, the ±15V system control power supply powers the error amplifier module, and the ±15V current sampling isolated power supply powers the operational amplifier of the current feedback module.

[0024] Preferably, the safety protection unit of the output module includes a controlled output relay, an overvoltage protection circuit, and an overcurrent protection circuit; the controlled output relay is used to control the switching of current output, and the overvoltage protection circuit and the overcurrent protection circuit are used to protect the amplifier under abnormal operating conditions.

[0025] A high-load, wideband, high-current power amplification method for testing traveling wave ranging devices includes the following steps:

[0026] (1) The external input signal is received through the signal conditioning module, and the pre-processed signal is obtained after differential isolation, zero-point adjustment and gain fine-tuning.

[0027] (2) The error amplification module receives the preprocessed signal, compares and amplifies it with the differential feedback signal and the current sampling feedback signal, and generates an error driving signal;

[0028] (3) The driving module amplifies the error driving signal and outputs it to the power amplifier module;

[0029] (4) The power amplifier module converts the amplified drive signal into a high current signal through a multi-power device parallel structure;

[0030] (5) The current feedback module collects the load current corresponding to the large current signal, processes it to generate the current sampling feedback signal and sends it back to the error amplification module;

[0031] (6) A power module with a multi-level isolated power supply architecture, providing an adapter power supply for each module;

[0032] (7) The output module outputs the high current signal and monitors and protects against abnormal operating conditions through the safety protection unit.

[0033] Preferably, in step (2), the differential feedback signal is generated by a voltage divider circuit consisting of a capacitor, a first resistor, and a second resistor, which generates strong negative feedback to the high-frequency signal to suppress high-frequency oscillation; the current sampling feedback signal makes the amplifier output impedance close to the characteristics of an ideal current source, ensuring that the output current is stable when the load impedance changes.

[0034] Preferably, in step (5), the current sampling unit of the current feedback module collects the load current through the sampling resistor, and after preliminary amplification by the operational amplifier, it is further processed by the common-mode rejection amplification unit for differential amplification and common-mode rejection to eliminate the influence of load potential fluctuations on sampling accuracy.

[0035] Preferably, the method is used for testing a traveling wave ranging device, injecting a high-peak, wide-bandwidth fault current traveling wave signal into the traveling wave ranging device, which includes a primary high-frequency current transformer; the high-peak current is 100A peak value, and the wide-bandwidth frequency range is DC to 500kHz.

[0036] Compared with the prior art, the present invention has the following beneficial technical effects:

[0037] 1. Through innovative modular architecture and dual-loop feedback control, it achieves DC to 500kHz wideband coverage while ensuring low distortion, and stably outputs 100A peak current. It can drive high-impedance loads (such as primary high-frequency current transformers) in traveling wave ranging equipment, truly reproduce fault traveling wave signals, and solve the problems of narrow bandwidth and weak load capacity of existing amplifiers.

[0038] 2. Using Class A power amplifier as the core topology, the switching noise and signal distortion problems of switching amplifiers are fundamentally eliminated. Combined with differential feedback and current negative feedback composite control, the signal fidelity in a wide bandwidth is ensured, providing an accurate signal source for the accuracy verification of traveling wave ranging devices.

[0039] 3. The four-level isolation power supply architecture achieves effective isolation between high and low voltage, power and signal, greatly reducing mutual interference. At the same time, overvoltage and overcurrent protection circuits and floating sampling design improve system stability and safety, making it suitable for use in various scenarios such as laboratory research and development, factory verification and field operation and maintenance.

[0040] 4. A bridge drive structure is constructed using a general-purpose high-voltage operational amplifier, replacing the scarce high-parameter dedicated operational amplifiers and reducing hardware costs. At the same time, the module has a high degree of functional integration, and the operation process is adapted to the testing habits of traveling wave ranging devices. It can be directly used for device R&D quality control and factory verification, which is of great significance to ensuring the safe operation of the power grid and has high practical value and market prospects. Attached Figure Description

[0041] Figure 1 This is a structural block diagram of a high-load, wideband, high-current power amplifier for testing traveling wave ranging devices according to the present invention.

[0042] The meanings of the labels in the diagram and their correspondence with the text modules in the instruction manual are as follows:

[0043] "Signal Conditioning Input": This refers to the function label of "Signal Conditioning Module" in the instruction manual, which corresponds to the differential isolation, zero-point adjustment and gain fine-tuning functions of external input signals;

[0044] "Comprehensive Error Amplifier": This refers to the core component labeled "Error Amplification Module" in the instruction manual. It corresponds to the comparison and amplification of the preprocessed signal and the dual feedback signal (differential feedback and current sampling feedback) to generate an error driving signal.

[0045] "Bridge drive": This refers to the structural labeling of the "drive module" in the instruction manual. It corresponds to a bridge amplification structure composed of two high-voltage operational amplifiers, which realizes a 4-fold voltage amplification of the error drive signal.

[0046] "Class A power amplifier": This refers to the topology label of "power amplifier module" in the instruction manual. It corresponds to a Class A power amplifier circuit that uses a multi-MOS parallel structure to achieve high current signal output.

[0047] "Current sampling amplification" and "high common-mode rejection amplifier": together constitute the "current feedback module" in the instruction manual. "Current sampling amplification" corresponds to the current sampling unit (including high-precision sampling resistor R3 and operational amplifier), and "high common-mode rejection amplifier" corresponds to the common-mode rejection amplification unit (including high-voltage operational amplifier and precision matching resistor). The two work together to complete the load current acquisition and common-mode interference cancellation.

[0048] "Isolation Power Supply", "High-Power High-Voltage Power Supply", and "Conventional Power Supply": Together they constitute the multi-level isolation architecture of the "Power Module" in the instruction manual. Among them, the "High-Power High-Voltage Power Supply" is a ±54V high-power power supply (for the power amplification module), the "Isolation Power Supply" includes a ±36V pre-stage drive power supply (for the drive module), and the "Conventional Power Supply" includes a ±15V system control power supply (for the error amplification module) and a ±15V current sampling isolation power supply (for the current feedback module).

[0049] "Current Output": This refers to the signal output terminal labeled "Output Module" in the instruction manual. It integrates a controlled output relay, overvoltage protection circuit, and overcurrent protection circuit to achieve safe output and abnormal protection of high current signals.

[0050] In the diagram, the component symbols R1, R2, and C correspond to the differential feedback voltage divider circuit of the error amplification module, R3 corresponds to the sampling resistor of the current feedback module, and U2 corresponds to the core operational amplifier of the high common-mode rejection amplifier. The functions of each component are consistent with the text description in the instruction manual. Detailed Implementation

[0051] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. It should be noted that these descriptions are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0052] I. System Overall Architecture and Module Deployment

[0053] refer to Figure 1 The system structure block diagram shown in this embodiment of the invention provides a high-load, wide-bandwidth, high-current power amplifier for testing traveling wave ranging devices. It includes a signal conditioning module, an error amplification module, a drive module, a power amplification module, a current feedback module, a power supply module, and an output module. Each module is cascaded through a PCB board to achieve signal and power transmission. The entire unit is encapsulated in a metal shielded chassis to reduce external electromagnetic interference and adapt to the complex field environment of power distribution network operation and maintenance testing.

[0054] II. Specific Implementation Details of Each Module

[0055] 1. Signal Conditioning Module

[0056] Structure and Function Implementation: The module employs a differential structure to receive external input signals. Leveraging its high input impedance and high common-mode rejection ratio, it suppresses common-mode interference introduced by the transmission line (such as 50Hz power frequency interference in the field). The module integrates a high-precision zero-point adjustment circuit and a gain fine-tuning circuit. The zero-point adjustment circuit eliminates DC bias and the module's own offset voltage, controlling the DC bias within ±1mV to ensure zero-point stability of the power amplifier output. The gain fine-tuning circuit adjusts the input signal to the optimal level (0.1-5V) required by the subsequent power amplifier module according to the designed turns ratio, providing the system with a clean, stable, and precisely proportioned reference signal, generating a pre-processed signal that is transmitted to the error amplifier module.

[0057] 2. Error Amplification Module

[0058] Dual-loop control architecture: A dual-loop control architecture with an operational amplifier as the core is constructed, consisting of a voltage loop and a current loop. It receives the pre-processed signal, differential feedback signal, and current sampling feedback signal output from the signal conditioning module, and generates an error driving signal through signal comparison and amplification. The differential feedback network consists of a voltage divider circuit composed of capacitor C, first resistor R1 (in series), and second resistor R2, which is connected to the inverting input port of the operational amplifier. Based on the characteristic of the capacitor's impedance decreasing at high frequencies, it generates stronger negative feedback for high-frequency signals, effectively suppressing high-frequency oscillations in the system (in actual measurements, it can increase the phase margin in the high-frequency band to over 60°). The current sampling feedback signal is connected to the non-inverting input port of the operational amplifier, forming a 180° phase difference with the pre-processed signal, thus constituting negative feedback in the current loop. This increases the amplifier's output impedance to over 10^6Ω, approaching the characteristics of an ideal current source—when the load impedance changes from near 0Ω to 10Ω, the output current fluctuation is ≤0.5%, meeting the driving requirements of high-impedance loads (such as primary high-frequency current transformers, where the high impedance is typically above 2Ω).

[0059] 3. Driver Module

[0060] Bridge-type drive structure: Two high-voltage operational amplifiers are used to form a bridge-type drive structure. The upper-stage error drive signal is divided into two paths after being divided by resistors: one path is directly connected to the non-inverting input of the first high-voltage operational amplifier, and the other path is connected to the inverting input of the second high-voltage operational amplifier after being inverted. The voltage amplification factor of a single high-voltage operational amplifier is fixed at 2 times by an external feedback resistor (the ratio of feedback resistor to input resistor is 1:1). After the bridge output, the overall voltage amplification factor is 4 times (the outputs of the two operational amplifiers are superimposed, and the voltage is 4 times that of a single operational amplifier output). At the same time, the output of the second high-voltage operational amplifier is connected to the power ground of the power amplifier module, and the output of the first high-voltage operational amplifier is a floating potential. With the power supply of the appropriate pre-stage drive power supply, high-voltage drive output can be achieved, solving the problem of the scarcity of commercial operational amplifiers with high-voltage drive, while ensuring no phase delay for 500kHz high-frequency signals and a slew rate ≥100V / μs.

[0061] 4. Power Amplifier Module

[0062] Parallel connection of multiple power devices and Class A operation: Multiple MOSFETs with low gate charge and low junction capacitance are used as power output transistors, and the current output capability is improved through parallel connection. Each MOSFET has an independent 51Ω gate resistor in series, achieving an optimal balance between "gate oscillation and electromagnetic interference caused by excessively small gate resistance" and "switching speed, slew rate and bandwidth limited by excessively large gate resistance", avoiding the driving difficulties and high-frequency response attenuation problems caused by multiple MOSFETs in parallel connection. By adjusting the bias resistor, the MOSFET static current is maintained at the appropriate value, ensuring that the MOSFET operates in the linear region throughout the entire signal cycle (measured THD+N≤0.1%@1kHz). After multiple MOSFETs are connected in parallel, the output current capability can be increased to 100A peak (continuous output current 50A), which meets the requirement of "injecting large current transient signals on the primary side" in the testing of traveling wave ranging devices (such as simulating a 100A peak current during a short circuit fault).

[0063] 5. Current feedback module

[0064] Current Sampling and Common-Mode Rejection Processing: The current feedback module includes a current sampling unit and a common-mode rejection amplifier unit. The current sampling unit contains a high-precision, low-temperature-drift sampling resistor R3 and an operational amplifier. The sampling resistor is connected in series between the output of the power amplifier module and the load to directly detect the load current. The operational amplifier is powered by an isolated power supply, and its power supply ground is the same as the high-side ground of the sampling resistor (power output ground), forming a "floating" sampling system to avoid the influence of load potential fluctuations (such as ±100V fluctuations) on the sampling reference. Since the potential of the power output stage fluctuates significantly with load changes, the output signal of the current sampling unit will be superimposed with a high common-mode voltage. Therefore, a common-mode rejection amplifier unit is set up—with a high-voltage operational amplifier as the core and four precision matching resistors to build a differential amplification structure, which can improve the common-mode rejection ratio to over 80dB. The final output current sampling feedback signal amplitude error is ≤0.2%, which is fed back to the error amplification module to achieve closed-loop control.

[0065] 6. Power Module

[0066] Four-level isolation power supply architecture implementation: The power supply module adopts a four-level isolation power supply architecture based on functional partitioning, providing adaptive power to each module, while achieving effective isolation between high and low voltage, power and signal.

[0067] ±54V high-power power supply: directly supplies power to the power amplifier module, supports 100A peak current output, ripple ≤50mV, and meets the power requirements under high load;

[0068] ±36V pre-amplifier power supply: supplies power to the two high-voltage operational amplifiers of the driver module, with an isolation voltage of ≥3kV, ensuring the high-voltage output capability of the bridge driver;

[0069] ±15V system control power supply: supplies power to the error amplification module, with output ripple ≤1mV to ensure stable operation of the control logic;

[0070] ±15V current sampling isolation power supply: supplies power to the operational amplifier of the current feedback module, making its ground and power ground share the same potential, fundamentally solving the problem of ground potential fluctuation caused by load changes, and realizing high-precision sampling in harsh noise environments;

[0071] Anti-interference design: Isolation and filtering measures are adopted between each power supply module. The measured crosstalk between modules is ≤-80dB, which avoids mutual interference affecting the system stability.

[0072] 7. Output Module

[0073] Safety On / Off and Protection: The output module integrates a controlled output relay and a safety protection unit. The controlled output relay is used to achieve safe on / off switching of the current signal, adapting to the start / stop requirements in the test process and avoiding module damage caused by hot-swapping. The safety protection unit includes an overvoltage protection circuit and an overcurrent protection circuit, serving as the last line of defense under abnormal system conditions. The overvoltage protection circuit can absorb transient power and suppress overvoltage at the output terminal. The overcurrent protection circuit detects the load current through a sampling resistor. When the current exceeds a set threshold (such as a peak value of 120A), it quickly cuts off the output to prevent power devices from being damaged by overcurrent. The protection response time is ≤1μs.

[0074] III. Specific Implementation Process of Power Amplification Method

[0075] Taking the "500kHz fault current traveling wave test of a complete traveling wave ranging device (including a primary high-frequency current transformer + traveling wave test core device)" as an example, the execution steps of the power amplification method are explained in detail:

[0076] Step 1: Signal Conditioning

[0077] An external signal generator outputs a 500kHz, 1V amplitude sine wave signal (simulating the high-frequency component of a fault traveling wave), which is then connected to the signal conditioning module.

[0078] The differential structure suppresses common-mode interference in the field, the zero-point adjustment circuit cancels the DC bias of the signal to the appropriate range (such as 0.5mV), and the gain fine-tuning circuit amplifies the signal amplitude to 5V to generate a pre-processed signal.

[0079] Step 2: Error Amplification

[0080] The error amplification module receives a 5V preprocessed signal and simultaneously acquires a differential feedback signal (generated by a voltage divider circuit consisting of capacitor C, first resistor R1, and second resistor R2) and a current sampling feedback signal.

[0081] Differential feedback generates strong negative feedback for 500kHz high-frequency signals, suppressing system oscillations; current sampling feedback stabilizes the amplifier's output impedance and generates a suitable error drive signal (such as 10V).

[0082] Step 3: Signal Drive

[0083] The two high-voltage operational amplifiers of the drive module amplify the error drive signal in a bridge configuration and output a high-voltage drive signal (e.g., 40V) that has been amplified four times, which is then transmitted to the power amplifier module.

[0084] Step 4: Power Amplification

[0085] Multiple parallel MOSFETs, under the action of a high-voltage drive signal, convert the signal into a 500kHz high-current signal with a peak value of 100A (the measured current amplitude error is ≤1%), and output it to the load (primary high-frequency current transformer).

[0086] Step 5: Current Feedback

[0087] The sampling resistor R3 collects a 100A load current and generates a sampling voltage. The operational amplifier of the current sampling unit amplifies the sampling voltage to an appropriate amplitude (such as 5V), and then the common-mode rejection amplifier eliminates common-mode interference, generating a current sampling feedback signal that is sent back to the error amplification module to achieve current closed-loop control (measured current stability ±0.3%).

[0088] Step 6: Power Supply

[0089] Four-level isolated power supply synchronous power supply: ±54V high-power power supply provides power to MOSFETs, ±36V pre-stage drive power supply drives high-voltage operational amplifiers, ±15V system control power supply ensures error amplification stability, and ±15V sampling isolation power supply ensures sampling accuracy.

[0090] Step 7: Safe Output

[0091] The relay of the output module is activated, injecting a 500kHz current signal with a peak value of 100A into the high-frequency current transformer; the overvoltage / overcurrent protection circuit monitors the operating conditions in real time, and quickly cuts off the output to protect the system safety when the load is abnormal (such as a sudden drop in impedance causing the current to exceed the threshold).

[0092] IV. Implementation Results Verification

[0093] Through the above implementation methods, this power amplifier and method can achieve the following performance indicators, fully meeting the testing requirements of traveling wave ranging devices:

[0094] Frequency band coverage: DC to 500kHz, with current amplitude fluctuation ≤5% across the entire frequency band;

[0095] Current output: Peak current 100A, continuous current 50A, meeting the primary side signal injection requirements;

[0096] Load capacity: Output current fluctuation ≤0.5% within a load impedance range of 0-10Ω;

[0097] Signal fidelity: THD+N≤0.1%@1kHz, 500kHz signal phase delay≤5ns;

[0098] Safety: Overvoltage / overcurrent protection response time ≤1μs, module operating temperature can be adapted to field environment from -20℃ to +60℃.

[0099] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and these variations still fall within the protection scope of the present invention.

Claims

1. A high-load, wideband, high-current power amplifier for testing traveling wave ranging devices, characterized in that, It includes a signal conditioning module, an error amplification module, a driver module, a power amplification module, a current feedback module, a power supply module, and an output module; The signal conditioning module is used to receive and preprocess external input signals; The error amplification module receives the preprocessed signal and feedback signal output by the signal conditioning module, and generates an error driving signal through signal comparison and amplification; the feedback signal includes a differential feedback signal and a current sampling feedback signal; the differential feedback signal is generated by a voltage divider circuit consisting of a capacitor and a first resistor connected in series, and then a second resistor, and the voltage divider circuit is connected to the inverting input port of the operational amplifier of the error amplification module; the current sampling feedback signal has a 180° phase difference with the preprocessed signal and is connected to the non-inverting input port of the operational amplifier; The driving module receives the error driving signal output by the error amplification module, amplifies the signal, and then transmits it to the power amplification module. The power amplifier module adopts a parallel structure of multiple power devices to convert the signal output by the drive module into a high current signal; The current feedback module collects the load current output by the power amplifier module, processes it to generate the current sampling feedback signal, and sends it back to the error amplifier module. The power module is a multi-level isolated power architecture, providing adaptive power to each module of the amplifier. The output module is used to output high current signals and integrates a safety protection unit.

2. The power amplifier according to claim 1, characterized in that, The signal conditioning module adopts a differential structure and integrates a zero-point adjustment unit and a gain fine-tuning unit. The differential structure has high input impedance and high common-mode rejection ratio. The zero-point adjustment unit is used to eliminate DC bias of the signal and the module's own offset voltage. The gain fine-tuning unit is used to adjust the input signal to a level suitable for the power amplifier module.

3. The power amplifier according to claim 1, characterized in that, The driving module consists of a bridge driving structure composed of two high-voltage operational amplifiers. The upper-level signal is connected to the non-inverting input and the inverting input of the two high-voltage operational amplifiers respectively. The voltage amplification factor of a single high-voltage operational amplifier is 2 times, and the overall voltage amplification factor after bridge output is 4 times. The output terminal of one of the high-voltage operational amplifiers shares a common ground with the power amplification module.

4. The power amplifier according to claim 1, characterized in that, The power amplifier module uses a MOSFET with low gate charge and low junction capacitance, and the gate of the MOSFET is connected in series with a gate resistor with a resistance of 51 ohms.

5. The power amplifier according to claim 1, characterized in that, The current feedback module includes a current sampling unit and a common-mode rejection amplifier unit. The current sampling unit includes a high-precision, low-temperature drift sampling resistor and an operational amplifier. The sampling resistor is connected in series between the power amplifier module and the load. The operational amplifier is powered by an isolated power supply, and the power supply ground of the operational amplifier and the high-side ground of the sampling resistor are common to form a floating sampling system. The common-mode rejection amplifier unit consists of a high-voltage operational amplifier and four precision matching resistors forming a differential amplifier structure.

6. The power amplifier according to claim 1, characterized in that, The power module's multi-stage isolated power supply includes a ±54V high-power power supply, a ±36V pre-stage drive power supply, a ±15V system control power supply, and a ±15V current sampling isolated power supply. The ±54V high-power power supply powers the power amplifier module, the ±36V pre-stage drive power supply powers the drive module, the ±15V system control power supply powers the error amplifier module, and the ±15V current sampling isolated power supply powers the operational amplifier of the current feedback module.

7. The power amplifier according to claim 1, characterized in that, The safety protection unit of the output module includes a controlled output relay, an overvoltage protection circuit, and an overcurrent protection circuit; the controlled output relay is used to control the switching of current output, and the overvoltage protection circuit and the overcurrent protection circuit are used to protect the amplifier under abnormal operating conditions.

8. A high-load, wideband, high-current power amplification method for testing traveling wave ranging devices, characterized in that, Includes the following steps: (1) The external input signal is received through the signal conditioning module, and the pre-processed signal is obtained after differential isolation, zero-point adjustment and gain fine-tuning. (2) The error amplification module receives the preprocessed signal, compares and amplifies it with the differential feedback signal and the current sampling feedback signal, and generates an error driving signal. The differential feedback signal is generated by a voltage divider circuit composed of a capacitor, a first resistor and a second resistor and is connected to the inverting input port of the operational amplifier of the error amplification module. The current sampling feedback signal has a 180° phase difference with the preprocessed signal and is connected to the non-inverting input port of the operational amplifier. (3) The driving module amplifies the error driving signal and outputs it to the power amplifier module; (4) The power amplifier module converts the amplified drive signal into a high current signal through a multi-power device parallel structure; (5) The current feedback module collects the load current corresponding to the large current signal, processes it to generate the current sampling feedback signal and sends it back to the error amplification module; (6) A power module with a multi-level isolated power supply architecture, providing an adapter power supply for each module; (7) The output module outputs the high current signal and monitors and protects against abnormal operating conditions through the safety protection unit.

9. The amplification method according to claim 8, characterized in that, In step (2), the differential feedback signal is generated by a voltage divider circuit consisting of a capacitor, a first resistor, and a second resistor, which generates strong negative feedback to the high-frequency signal to suppress high-frequency oscillation; the current sampling feedback signal makes the amplifier output impedance close to the characteristics of an ideal current source, ensuring that the output current is stable when the load impedance changes.

10. The amplification method according to claim 8, characterized in that, In step (5), the current sampling unit of the current feedback module collects the load current through the sampling resistor. After being initially amplified by the operational amplifier, it is then subjected to differential amplification and common-mode rejection processing by the common-mode rejection amplification unit to eliminate the influence of load potential fluctuations on sampling accuracy.

11. The amplification method according to claim 8, characterized in that, The method is used for testing a traveling wave ranging device, injecting a high-peak, wide-bandwidth fault current traveling wave signal into the traveling wave ranging device, which includes a primary high-frequency current transformer; the high-peak current is 100A peak value, and the wide-bandwidth frequency range is DC to 500kHz.

Images