Multi-data voltage frequency signal acquisition system and method for dynamic voltage restorer

Abstract

The present invention discloses a voltage frequency signal acquisition system, including an acquisition module, a main control module, and a detection module. The acquisition module is connected to the main control module. The acquisition module is used to transmit the collected voltage information to the main control module according to the control instruction of the main control module. The main control module obtains a voltage frequency signal after processing the transmitted voltage information; the main control module is connected to the detection module. The detection module is used to detect faults on the data transmitted by the acquisition module and feed back the fault signal to the main control module. The main control module confirms whether to re-drive the acquisition module to upload the collected voltage information according to the fault detection module. The advantages of the present invention are: three modules are used to collect three-phase voltage frequency signals, which has modular characteristics and is conducive to integration and fault detection; fault judgment is performed on the detected data, and the acquisition module is driven to re-collect in time after a fault occurs, so as to ensure the stability of the collected data.

Description

Technical Field

[0001] The present invention relates to the technical field of voltage detection, and in particular to a system for collecting multi-data voltage frequency signals for a dynamic voltage restorer system. Background Art

[0002] Signal acquisition is of great significance for feedback control and data statistics of power systems. How to effectively collect a variety of different voltage signals is an important step in solving many problems. There are few multi-data and multi-function voltage and frequency signal acquisition templates on the market, and the design is relatively complex and the price is relatively expensive. Summary of the invention

[0003] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a collection system capable of accurately collecting voltage and frequency signals for collecting voltage and frequency signals of a power grid.

[0004] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a voltage frequency signal acquisition system, including an acquisition module, a main control module, and a detection module. The acquisition module is connected to the main control module. The acquisition module is used to transmit the collected voltage information to the main control module according to the control instruction of the main control module. The main control module obtains the voltage frequency signal after processing according to the transmitted voltage information; the main control module is connected to the detection module. The detection module is used to detect faults on the data transmitted by the acquisition module and feed back the fault signal to the main control module. The main control module confirms whether to re-drive the acquisition module to upload the collected voltage information according to the fault detection module.

[0005] The main control module includes a DSP processor.

[0006] The number of acquisition modules is three, including phase A acquisition module, phase B acquisition module, and phase C acquisition module, which correspond to one of the three-phase electricity respectively. The three modules are respectively used to detect one phase through the acquisition module integration method, which is convenient for timely confirmation of the faulty module in case of failure and for driving and controlling the corresponding phase acquisition module to re-detect data.

[0007] The acquisition module includes a Hall voltage sensor, a phase-locked loop circuit, a sampling and holding circuit, an AD conversion circuit, and an adding circuit. The output end of the Hall voltage sensor is respectively connected to the sampling and holding circuit and the phase-locked loop circuit. The output end of the phase-locked loop circuit outputs a synchronous sampling pulse to the sampling and holding circuit for supervising the sampling frequency of the voltage signal. The output end of the sampling and holding circuit is connected to the AD conversion circuit. The output end of the AD conversion circuit is connected to the I / O interface of the DSP controller after passing through the adding circuit.

[0008] The detection module is used to detect the voltage information input by the I / O interface of the DSP controller. When the voltage input by any of the three voltage acquisition modules is faulty or no voltage data is transmitted to the I / O, the data transmitted by the acquisition module corresponding to the I / O interface is judged to be faulty. At this time, the DSP controller outputs a control signal to the acquisition module to resample the data.

[0009] A multi-data voltage frequency signal acquisition method for a dynamic voltage restorer uses three voltage sensors to respectively acquire voltage data of one phase of three-phase electricity, and performs fault identification on the acquired signal of each phase. When a fault occurs, the acquisition is performed again. When no fault occurs, the three-phase signal is sampled and the acquisition is synchronized with the measured voltage signal through a phase-locked loop. Then, the acquired voltage signal is sent to the I / O port of a DSP controller after passing through an addition circuit.

[0010] The advantages of the present invention are: using three modules to collect three-phase voltage frequency signals, having modular characteristics, being conducive to integration and fault detection; making fault judgment on the detected data, and timely driving the collection module to re-collect after a fault occurs, so as to ensure the stability of the collected data; and inputting into the DSP after passing through the adding circuit, so as to avoid damage to the DSP caused by excessive input voltage signals. The present invention is based on the sampling system of the DSP, and by having an adding circuit, the DSP circuit is sampled in a dynamic voltage device. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The following is a brief description of the contents expressed in the drawings of the present invention and the symbols in the drawings:

[0012] Figure 1 This is a structural principle diagram of the acquisition module of the present invention;

[0013] Figure 2 It is the overall structural block diagram of the acquisition system of the present invention;

[0014] Figure 3 It is a flow chart of the collection principle of the collection system of the present invention;

[0015] Figure 4 is the phase-locked loop circuit diagram;

[0016] Figure 5 This is the schematic diagram of the phase-locked loop;

[0017] Figure 6 This is the schematic diagram of the DSP chip;

[0018] Figure 7 The sine wave of the measured voltage and the square wave of the same frequency output by the comparator of the phase-locked loop;

[0019] Figure 8 This is the output waveform of the phase-locked loop. DETAILED DESCRIPTION

[0020] The specific implementation of the present invention will be further explained in detail below by describing the optimal embodiment with reference to the accompanying drawings.

[0021] The present invention provides a voltage frequency acquisition system for acquiring load or grid side voltage frequency data, such as Figure 1 , 2 As shown in , 3, the voltage frequency signal acquisition system includes an acquisition module, a main control module, and a detection module. The acquisition module is connected to the main control module. The acquisition module is used to transmit the collected voltage information to the main control module according to the control instruction of the main control module. The main control module obtains the voltage frequency signal after processing according to the transmitted voltage information; the main control module is connected to the detection module. The detection module is used to detect faults on the data transmitted by the acquisition module and feed back the fault signals to the main control module. The main control module confirms whether to re-drive the acquisition module to upload the collected voltage information according to the fault detection signal.

[0022] The main control module uses a DPS control system with a DSP processor as the core. There are three acquisition modules, including an A-phase acquisition module, a B-phase acquisition module, and a C-phase acquisition module, each corresponding to one of the three-phase electricity. The acquisition modules are integrated to use three modules to detect one phase respectively, which is convenient for timely confirmation of the faulty module in case of a fault and for driving and controlling the corresponding one-phase acquisition module to re-detect the data.

[0023] The acquisition module includes a Hall voltage sensor, a phase-locked loop circuit, a sampling and holding circuit, an AD conversion circuit, and an adding circuit. The output end of the Hall voltage sensor is respectively connected to the sampling and holding circuit and the phase-locked loop circuit. The output end of the phase-locked loop circuit outputs a synchronous sampling pulse to the sampling and holding circuit for supervising the sampling frequency of the voltage signal. The output end of the sampling and holding circuit is connected to the AD conversion circuit. The output end of the AD conversion circuit is connected to the I / O interface of the DSP controller after passing through the adding circuit.

[0024] The detection module is used to detect the voltage information input by the I / O interface of the DSP controller. When the voltage input by any of the three voltage acquisition modules is faulty or no voltage data is transmitted to the I / O, the data transmitted by the acquisition module corresponding to the I / O interface is judged to be faulty. At this time, the DSP controller outputs a control signal to the acquisition module to resample the data.

[0025] like Figure 3The acquisition method of the multi-data voltage frequency signal acquisition system of a dynamic voltage restorer is shown. The voltage data of one phase of the three-phase electricity is collected by three voltage sensors respectively, and the collected signals of each phase are respectively judged for faults. When a fault occurs, the acquisition is performed again. When no fault occurs, the three-phase signal is sampled and the acquisition is synchronized with the measured voltage signal through a phase-locked loop. Then the collected voltage signal is sent to the I / O port of the DSP controller after passing through an addition circuit. The voltage frequency signal is collected from the load side and fed back to the grid side. The grid side calculates whether the voltage is within the upper and lower limits and whether the compensation is effective to determine whether the sampled voltage is valid. If the sampled voltage does not meet the requirements, the grid side calculation loop is entered again until the sampled voltage meets the requirements and sampling can be performed. The acquisition module version detection system provided by the invention accurately detects the version of the acquisition module, is easy to operate, has high efficiency, and low labor cost.

[0026] The present invention has the characteristics of sharing single-phase acquisition and three-phase acquisition. The voltage and frequency data of each phase are respectively collected through the acquisition modules corresponding to phases A, B and C. Three-phase acquisition is constructed by single-phase acquisition. It has the characteristics of modularization and integration. It is convenient for fault detection when three-phase is constructed by a single phase.

[0027] The voltage sensor model used in this application is the component parameters of the VSM025A Hall voltage sensor. The main advantage of using this chip is that it can measure DC, AC, pulse and various irregular voltages under electrical isolation conditions, thereby realizing the collection of multi-functional multi-input voltage signals.

[0028] Figure 1 is the main acquisition principle diagram of the acquisition system of the present invention, which includes the main phase-locked loop link and the grid voltage sampling technology. The phase-locked loop link is used to generate synchronous sampling pulses, and the input voltage frequency is strictly regulated by the sampling pulse frequency. Since the phase-locked loop is a closed-loop regulation system, the phase-locked loop enters a locked state after the phases of the two signals are continuously reduced and tend to 0, realizing the synchronization of the sampling pulse and the detected voltage. The grid voltage sampling technology plays an important role in the sampling accuracy in sampling detection, so the grid voltage selects the high-voltage differential amplifier input port.

[0029] Figure 4 is a phase-locked loop circuit diagram of the present invention, Figure 5The schematic diagram of the phase-locked loop. The chip TLC272 is the power selection chip; the chip CD4046 is used to implement the phase-locked loop. Pin 3 is connected to pin 14 on the chip CD4518, pin 4 is connected to pin 1 on the CD4518, and pin 2 of the AND gate chip 7408. Pin 5 is grounded, pins 6 and 7 are indirectly connected to a 0.25uf capacitor, pin 8 is grounded, pin 9 is grounded through a 100k resistor R3 and capacitor C2, pin 11 is grounded through a resistor R1, pin 13 is grounded through a 1M resistor R4 and a 100K resistor R3 capacitor C2, pin 14 is connected to node B, and node 16 is connected to a 15V power supply. The meaning of CD4046 phase locking is the automatic control of phase synchronization, and its function is to complete the automatic control of the phase synchronization of two electrical signals. The closed-loop system is called a phase-locked loop, or PLL for short. The phase-locked loop mainly consists of a phase comparator (PC), a voltage-controlled oscillator (VCO), and a low-pass filter. The chip CD4518 is a binary / decimal (8421 encoding) synchronous adding counter; the power selection chip TLC272: AND gate, realizing logical AND operation; the components of the VSM025A Hall voltage sensor: pin 1 is connected to the positive pole of the power supply, pin 2 is connected to the negative pole of the power supply through resistor R7, pin 3 is connected to the -15V power supply, pin 4 is connected to the +15V power supply, and pin 5 is grounded through 100K resistor R6 and 100K variable resistor R5.

[0030] The addition circuit uses a single power supply and an onboard negative voltage generator. The power supply range is selected according to the needs, which determines the effective output range of the signal. When the power supply is 12V: the onboard internal voltage is effective +9V and -9V, and the effective output theoretical range is ±7.5V. When the power supply is 24V: the onboard internal voltage is effective +12V and -12V, and the effective output theoretical range is ±11.5V. It can realize the addition or subtraction function of two AC and DC voltages; the addition and subtraction operation circuit is composed of an integrated operational amplifier as the core component. Multiple input signals act on the in-phase input or inverting input of the operational amplifier respectively to realize the addition and subtraction of the input signal. The external resistor determines the proportional system of the input signal. In the addition and subtraction operation circuit, the input end of the operational amplifier has a common-mode signal component. In order to make the common-mode output zero and compensate for the average bias current and drift influence of the operational amplifier, it is usually required that the input resistance of the operational amplifier is balanced, that is, the resistance connected to the inverting input and the in-phase input of the operational amplifier is equal.

[0031] The three-phase voltage acquisition system of the present invention can be realized in a single phase and tested in three phases. It has modular characteristics, which is conducive to integration and fault detection. It realizes the acquisition of voltage and frequency of input signals. The overall effect has modular characteristics, which is easy for the sampling module to detect. It can detect three groups of single phases at the same time, which is easy for single-phase and three-phase modules to realize and detect faults. The three-phase acquisition system is through three single-phase acquisition systems. The collected signals are transmitted to the DSP main control system for signal processing, realizing the phase-locked loop waveform of inputting the same frequency square wave, N times pulse, and inverted output waveform, and the signal output to the DSPI / O port through the addition circuit, etc. Figure 3 In the three-phase signal sampling flow chart, the phase sampling signal passes through the sensor into the comparison circuit to compare the sizes of the two voltages. The high or low level of the output voltage is used to represent the size relationship of the two input voltages. When the voltage at the "+" input terminal is higher than that at the "-" input terminal, the voltage comparator outputs a high level; when the voltage at the "+" input terminal is lower than that at the "-" input terminal, the voltage comparator outputs a low level; it can work in the linear working area and the nonlinear working area.

[0032] The control sampling signal is further output and the fault signal is judged at the same time. If a fault signal is identified, it enters the comparison circuit with the sampling signal for sampling again. If there is no fault, it enters the integrated module for three-phase signal acquisition, and the sampling voltage is synchronized with the measured voltage signal at the same time, and finally input into the main control MCU.

[0033] like Figure 6 This is the chip pin schematic diagram of the DSP used in this application, and gives the wiring diagram of the DSP and the sampling interface part.

[0034] This article uses software to set the AC signal at the input end to 220V, 50HZ voltage for sampling. Figure 7 The waveform shown is the sine wave of the measured voltage passing through the voltage sensor VSM025A, and then converted into a square wave of the same frequency through the comparator LM339. Figure 7 In the above example, the voltage waveform under test is a sine wave in the upper half and a square wave of the same frequency in the lower half. Figure 8 As shown in the figure (the upper square wave is the output waveform of the phase-locked loop phase comparator, and the lower square wave is the pulse waveform of the voltage-controlled oscillator inside the phase-locked loop), the phase comparator outputs the waveform, and this pulse signal is the pulse waveform of the voltage-controlled oscillator inside the phase-locked loop. The waveform can change with the frequency of the measured signal, so that the sampling pulse frequency can always be kept within a cycle with a fixed sampling point, and the measurement accuracy is further improved.

[0035] Obviously, the specific implementation of the present invention is not limited to the above-mentioned methods. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention, they are all within the protection scope of the present invention.

Claims

1. A multi-data voltage frequency signal acquisition system for a dynamic voltage restorer, characterized in that: It includes an acquisition module, a main control module, and a detection module. The acquisition module is connected to the main control module. The acquisition module is used to transmit the collected voltage information to the main control module according to the control instruction of the main control module. The main control module obtains a voltage frequency signal after processing the transmitted voltage information; the main control module is connected to the detection module. The detection module is used to detect faults on the data transmitted by the acquisition module and feed back the fault signal to the main control module. The main control module confirms whether to re-drive the acquisition module to upload the collected voltage information according to the fault detection signal; the main control module includes a DSP processor; there are three acquisition modules, each corresponding to one of the three-phase electricity; the acquisition module includes a Hall voltage sensor, a phase-locked loop circuit, a sampling and holding circuit, an AD The output end of the Hall voltage sensor is connected to the sampling and holding circuit and the phase-locked loop circuit respectively. The output end of the phase-locked loop circuit outputs a synchronous sampling pulse to the sampling and holding circuit for supervising the sampling frequency of the voltage signal. The output end of the sampling and holding circuit is connected to the AD conversion circuit. The output end of the AD conversion circuit is connected to the I / O interface of the DSP controller after passing through the addition circuit. The detection module is used to detect the voltage information input by the I / O interface of the DSP controller. When the voltage input by any of the three voltage acquisition modules fails or no voltage data is transmitted to the I / O, it is judged that the data transmitted by the acquisition module corresponding to the I / O interface is faulty. At this time, the DSP controller outputs a control signal to the acquisition module to resample the data. The addition circuit is powered by a single power supply and an onboard negative voltage generator. The power supply range is selected according to needs. When the power supply is 12V, the onboard internal voltage is effective +9V and -9V, and the effective output theoretical range is ±7.5V. When the power supply is 24V, the onboard internal voltage is effective +12V and -12V, and the effective output theoretical range is ±11.5V, realizing the addition or subtraction function of two AC and DC voltages; the addition and subtraction operation circuit is composed of an integrated operational amplifier as the core component, and multiple input signals act on the in-phase input terminal or the inverting input terminal of the operational amplifier respectively to realize the addition and subtraction operation of the input signal, and the external resistor determines the proportional system of the input signal; the input terminal of the operational amplifier in the addition and subtraction operation circuit has a common-mode signal component. In order to make the common-mode output zero and compensate for the average bias current and drift influence of the operational amplifier, the input terminal resistance of the operational amplifier is required to be balanced, that is, the resistance connected to the inverting input terminal and the in-phase input terminal of the operational amplifier is equal.

2. A method for collecting multiple data voltage frequency signals of a dynamic voltage restorer according to claim 1, characterized in that: The voltage data of one phase of the three-phase electricity is collected by three voltage sensors respectively, and fault identification is performed according to the collected signal of each phase. When a fault occurs, the data is collected again. When no fault occurs, the three-phase signal is sampled and the collection is synchronized with the measured voltage signal through a phase-locked loop. The collected voltage signal is then sent to the I / O port of the DSP controller after passing through an adding circuit.

Images