A power amplifier for current loop fault detection

Abstract

The application discloses a power amplifier for current loop fault detection and belongs to the technical field of power amplifiers.The power amplifier comprises a control module, one end of the control module is connected with a direct digital frequency synthesizer (DDS), the input port of the DDS is connected with a clock, and the output port of the DDS is connected with a first filter; the first filter is connected with a first integrator, the first integrator is connected with a second filter, the second filter is connected with a gain conditioning module, the gain conditioning module is connected with a high-pass filter module, the high-pass filter module is connected with a sampling circuit, and the sampling circuit is connected with the first input port of a second integrator; the other end of the control module is connected with a digital-to-analog converter (DAC), the input port of the DAC is connected with a reference circuit chip, the output port of the DAC is connected with the second input port of the second integrator, and the output port of the second integrator is connected with the first integrator; and the application can output high-frequency signals in real time and stably based on feedback signals through the design of a new module of the power amplifier.

Description

TECHNICAL FIELD

[0001] The present application relates to a power amplifier for current loop fault detection, and belongs to the technical field of power amplifiers. BACKGROUND

[0002] The power metering system, as a main component of the benefit accounting of the entire power enterprise, plays a vital role in its operation process. The high-voltage power metering of the system is mainly composed of a current transformer (CT), a voltage transformer (PT), a power meter and other secondary side devices. The fault of any single component in the system may lead to inaccurate metering, and even may cause the entire high-voltage metering system to be in a paralyzed state. The existing methods for abnormal detection and fault diagnosis of the power metering system mostly need to input a stable high-frequency current signal, and then analyze the comparison between the input high-frequency current signal and the current signal output by the power metering system. Therefore, the amplifier capable of stably outputting a high-frequency signal becomes the key for the abnormal detection and fault diagnosis of the power metering system. SUMMARY

[0003] The technical problem to be solved by the present application is how to make the power amplifier stably output a high-frequency signal.

[0004] To solve the above technical problem, the technical solution provided by the present application is as follows: a power amplifier for current loop fault detection, comprising a control module, one end of the control module is connected with a direct digital frequency synthesizer (DDS), an input port of the DDS is connected with a clock, and an output port of the DDS is connected with a first filter; the first filter is connected with a first integrator, the first integrator is connected with a second filter, the second filter is connected with a gain conditioning module, the gain conditioning module is connected with a high-pass filter module, the high-pass filter module is connected with a sampling circuit, and a first input port of a second integrator is connected with the sampling circuit; the other end of the control module is connected with a digital-to-analog converter (DAC), an input port of the DAC is connected with a reference circuit chip, the reference circuit chip provides a reference driving voltage for the DAC, an output port of the DAC is connected with a second input port of the second integrator, and an output port of the second integrator is connected with the first integrator.

[0005] When a stable high-frequency signal needs to be sent out, the control module gives the digital value of the required high-frequency signal and transmits it to the DAC, the DAC converts the digital value into a stable and specially adjusted direct current voltage and transmits it to the second integrator as a reference signal; the second integrator transmits the received reference signal to the first integrator.

[0006] The control module controls the DDS to call the clock to emit a sine wave with stable frequency and adjustable phase and transmits it to the first filter to eliminate noise, and inputs the sine wave after the first filter eliminates noise into the first integrator; the first integrator integrates the input sine wave and a fixed signal to obtain a first integrated signal and inputs it into the second filter to eliminate noise;

[0007] The second filter inputs the first integrated signal after eliminating the clutter into the gain conditioning module and the high-pass filter module for processing to obtain a first compensated integrated signal. The first compensated integrated signal is collected by the sampling circuit and input into the first integrator for integration with the fixed signal to obtain a second integrated signal, which is transmitted to the first integrator and integrated with the sine wave to obtain a third integrated signal. At this time, the third integrated signal is a stable high-frequency signal.

[0008] Furthermore, the gain conditioning template includes a programmable gain amplifier, a first resistor R9, a second resistor R10, a third resistor R12, a fourth resistor R13, a first capacitor C47, a second capacitor C53 and a voltage regulator diode;

[0009] A first resistor R9 and a first capacitor C47 are connected in parallel between the negative input and output of the programmable amplifier; the negative input of the programmable amplifier is connected to a second resistor R10; the positive input of the programmable amplifier is respectively connected to the third resistor R12 and the second capacitor C53; the output of the programmable amplifier is connected to a fourth resistor R13 and a voltage regulator diode.

[0010] Furthermore, the high-pass filter circuit is composed of a capacitor and a resistor, and isolates low-frequency signals based on the principle that a capacitor isolates a direct current from an alternating current.

[0011] Furthermore, the sampling circuit uses a digital signal processor (DSP) as the control core, combined with a complex programmable logic device (CPLD) to form a DSP minimum control system. Signals are amplified by a programmable gain amplifier and collected in real time by a high-pass filter network. The collected instantaneous values ​​of the signals are then used to calculate the output signal's related electrical parameters through data processing.

[0012] Beneficial effects: The present invention adopts the design of a new module for the power amplifier, so that it can output high-frequency signals in real time and stably based on the feedback signal, and significantly reduce the noise and instability of the output signal, thereby greatly improving the accuracy of current loop fault detection and ensuring the reliability and accuracy of the detection results. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a structural schematic diagram of a power amplifier for stably outputting high-frequency signals according to the present invention.

[0014] Figure 2 4 is a circuit diagram of a gain adjustment module in an embodiment of the present invention.

[0015] Figure 3 Schematic diagram of the framework of the sampling circuit in an embodiment of the present invention. DETAILED DESCRIPTION

[0016] The following is a further description of a power amplifier for stably outputting high-frequency signals according to the present invention in conjunction with specific embodiments and accompanying drawings. Example

[0017] The power amplifier of this embodiment stably outputs high-frequency signals, such as Figure 1 As shown, it includes a control module, one end of the control module is connected to a direct digital frequency synthesizer DSS, the input port of the DDS is connected to a clock, and the output port of the DDS is connected to a first filter; the first filter is connected to a first integrator, the first integrator is connected to a second filter, and the second filter is connected to a gain conditioning module.

[0018] like Figure 2 As shown, the gain conditioning module includes a programmable gain amplifier, a first resistor R9, a second resistor R10, a third resistor R12, a fourth resistor R13, a first capacitor C47, a second capacitor C53 and a Zener diode; the first resistor R9 and the first capacitor C47 are connected in parallel between the negative input and output of the programmable amplifier; the negative input of the programmable amplifier is connected to the second resistor R10; the positive input of the programmable amplifier is respectively connected to the third resistor R12 and the second capacitor C53; the output of the programmable amplifier is connected to the fourth resistor R13 and the Zener diode.

[0019] The gain adjustment module is connected to the high-pass filter module. The high-pass filter circuit is composed of capacitors and resistors, and isolates low-frequency signals based on the principle that capacitors isolate DC from AC.

[0020] The high-pass filter module is connected to the sampling circuit, such as Figure 3 As shown, the sampling circuit uses a digital signal processor (DSP) as its control core. In this embodiment, a TMS320F28234 DSP is used. Combined with a complex programmable logic device (CPLD), it forms a DSP minimum control system. Signals are amplified by a programmable gain amplifier and acquired in real time through a high-pass filter network. The instantaneous values ​​of the acquired signals are then processed to calculate the relevant electrical parameters of the output signal.

[0021] The sampling circuit is connected with the first input port of the second integrator; the other end of the control module is connected with a digital-to-analog converter (DAC), the input port of the DAC is connected with a reference circuit chip, the reference circuit chip provides a reference driving voltage for the DAC; the output port of the DAC is connected with the second input port of the second integrator, and the output port of the second integrator is connected with the first integrator.

[0022] When a stable high-frequency signal is needed, the control module gives a digital value of the required high-frequency signal and transmits the digital value to the DAC, the DAC converts the digital value into a stable direct current voltage with a specific frequency and transmits the direct current voltage as a constant signal to the second integrator; the second integrator transmits the received constant signal to the first integrator;

[0023] The control module controls the DDS to call a clock to emit a sinusoidal wave with stable frequency and adjustable phase and transmits the sinusoidal wave to the first filter to eliminate the noise, the first filter eliminates the noise of the sinusoidal wave and inputs the sinusoidal wave to the first integrator; the first integrator integrates the input sinusoidal wave and the constant signal to obtain a first integrated signal and inputs the first integrated signal to the second filter to eliminate the noise;

[0024] The second filter inputs the first integrated signal after eliminating the noise to the gain conditioning module and the high-pass filter module to process the first integrated signal to obtain a first compensation integrated signal, the first compensation integrated signal is collected by the sampling circuit and input to the first integrator to integrate with the constant signal, to obtain a second integrated signal and transmit the second integrated signal to the first integrator to integrate with the sinusoidal wave to obtain a third integrated signal, the third integrated signal is the stable high-frequency signal.

Claims

1. A power amplifier for current loop fault detection, characterized in that: The invention comprises a control module, one end of which is connected to a direct digital frequency synthesizer (DDS), an input port of which is connected to a clock, and an output port of which is connected to a first filter; the first filter is connected to a first integrator, the first integrator is connected to a second filter, the second filter is connected to a gain conditioning module, the gain conditioning module is connected to a high-pass filter module, the high-pass filter module is connected to a sampling circuit, and the sampling circuit is connected to a first input port of the second integrator; the other end of the control module is connected to a digital-to-analog converter (DAC), the input port of the DAC is connected to a reference circuit chip, and the reference circuit chip provides a reference driving voltage to the DAC; the output port of the DAC is connected to the second input port of the second integrator, and the output port of the second integrator is connected to the first integrator; When a stable high-frequency signal needs to be emitted, the control module provides a digital value of the required high-frequency signal and transmits it to the DAC. The DAC converts the digital value into a DC voltage and transmits it as a constant signal to the second integrator. The second integrator transmits the received constant signal to the first integrator. The control module controls the DDS to call the clock to emit a sine wave with stable frequency and adjustable phase and transmits it to the first filter to eliminate noise, and inputs the sine wave after the first filter eliminates noise into the first integrator; the first integrator integrates the input sine wave and a fixed signal to obtain a first integrated signal and inputs it into the second filter to eliminate noise; The second filter inputs the first integrated signal after eliminating the clutter into the gain conditioning module and the high-pass filter module for processing to obtain a first compensated integrated signal. The first compensated integrated signal is collected by the sampling circuit and input into the second integrator for integration with the fixed signal to obtain a second integrated signal, which is transmitted to the first integrator and integrated with the sine wave to obtain a third integrated signal. At this time, the third integrated signal is a stable high-frequency signal.

2. The power amplifier according to claim 1, wherein: The gain conditioning module includes a programmable gain amplifier, a first resistor R9, a second resistor R10, a third resistor R12, a fourth resistor R13, a first capacitor C47, a second capacitor C53 and a voltage stabilizing diode; A first resistor R9 and a first capacitor C47 are connected in parallel between the negative input and output of the programmable gain amplifier; the negative input of the programmable gain amplifier is connected to a second resistor R10; the positive input of the programmable gain amplifier is connected to the third resistor R12 and the second capacitor C53 respectively; and the output of the programmable gain amplifier is connected to a fourth resistor R13 and a voltage stabilizing diode.

3. The power amplifier according to claim 1, wherein: The high-pass filter module is composed of capacitors and resistors, and isolates low-frequency signals based on the principle that capacitors isolate DC from AC.

4. The power amplifier according to claim 1, wherein: The sampling circuit uses a digital signal processor (DSP) as the control core and is combined with a complex programmable logic device to form a DSP minimum control system; the signal is amplified by a programmable gain amplifier and collected in real time by a high-pass filter network, and the output signal-related electrical parameters are calculated through data processing using the collected instantaneous value of the signal.

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