CN214011350U - Voltage sag monitoring device - Google Patents
Voltage sag monitoring device Download PDFInfo
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- CN214011350U CN214011350U CN202021611977.4U CN202021611977U CN214011350U CN 214011350 U CN214011350 U CN 214011350U CN 202021611977 U CN202021611977 U CN 202021611977U CN 214011350 U CN214011350 U CN 214011350U
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Abstract
The utility model provides a voltage sag monitoring device, which comprises an electric power parameter acquisition and conversion module 11, an analog-to-digital conversion module 12 and a detection processing module 13, wherein the electric power parameter acquisition and conversion module 11, the analog-to-digital conversion module 12 and the detection processing module 13 are connected in sequence; the electric power parameter acquisition and conversion module comprises a precision voltage transformer, a current transformer and a DSP; the precise voltage transformer and the precise current transformer are respectively connected with the three-phase input end of the power grid, and the output ends of the precise voltage transformer and the precise current transformer are respectively connected with the analog-to-digital conversion module; the analog-to-digital conversion module respectively converts the analog signals of the voltage, the current and the frequency into digital signals; and the detection processing module is used for carrying out voltage sag detection on the digital signal. The utility model provides a simple structure, the high voltage sag monitoring device of real-time update precision can accurate short-term test in real time out voltage sag characteristic quantity information, effectively shortens electric energy quality real-time detection's time, improves intelligent degree and safety precaution's function.
Description
Technical Field
The utility model belongs to the technical field of electric power system, concretely relates to voltage sag monitoring devices.
Background
A voltage sag generally refers to a voltage sag. The problems of transient electric energy quality mainly include voltage drop, sudden voltage rise, short-time power failure and the like.
The voltage drop generally refers to the time that the effective value of the power supply voltage rapidly drops to 90% -10% of the rated value and the duration is 0.5 cycle or about 1 minute. The voltage ramp is defined as a rapid rise in voltage effective value of 110% to 180% of the rated value for the same duration. If the duration exceeds l minutes, the voltage is considered to be lower or higher. Short power-off is defined as complete loss of power supply, duration of at least 1.5 cycle times, voltage drop test reference: IEC61000-4-11: 2004.
However, for these devices, voltage sags and interruptions of only a few cycles will cause serious influence and even damage to the sensitive power utilization devices. The voltage drop problem is a focus of attention on power quality problems due to the fact that the frequency of occurrence is far higher than that of short-time power failure, and even if faults are beyond hundreds of kilometers, local voltage amplitude drop can be caused.
The problem of power quality is more and more generally concerned by power supply departments and users, wherein the damage caused by the problem of voltage sag is the most serious, and the economic loss caused by the problem is quite huge.
The normal operation of the power system is difficult to avoid the power quality events such as voltage sag, and as the load proportion occupied by sensitive power users increases day by day, the information society pays more and more attention to the power quality. Therefore, the voltage sag can be detected quickly, accurately and effectively, and the method has important significance for safe and economic operation of a power system and reliable use of power by users.
Meanwhile, the power quality monitoring device is an important part in the research of a power quality monitoring terminal under the technical framework of a modern smart power grid, most of the voltage sag detection devices are large-scale equipment at present, the convenience of manual carrying, moving and operation is poor, the detection objects of the voltage sag detection devices at present are mainly power steady-state parameters, and the devices have rich detection indexes and high precision, but have complex equipment structures and are not suitable for power real-time dynamic parameters. Such as the Beijing Power Fault simulator PFS2216, LX-9830D multifunction voltage drop tester, Shanghai Saohshen VDT S10 single phase 10A voltage drop generator, etc.
Therefore, the problems of complex structure, slow real-time updating speed, unfriendly interactive interface, to-be-improved intellectualization and lack of early warning function existing in the conventional voltage sag device are urgently needed to be solved.
SUMMERY OF THE UTILITY MODEL
Complicated, the slow problem of real-time update nature of structure for solving current voltage sag device existence, the utility model provides a simple structure, the high voltage sag monitoring device of real-time update precision, include:
the device comprises an electric power parameter acquisition and conversion module, an analog-to-digital conversion module and a detection processing module, wherein the electric power parameter acquisition and conversion module, the analog-to-digital conversion module and the detection processing module are sequentially connected;
the electric power parameter acquisition and conversion module comprises a precision voltage transformer, a current transformer and a DSP; the input ports of the precision voltage transformer and the precision current transformer are respectively connected with the three-phase input end of the power grid, and the output ends of the precision voltage transformer and the precision current transformer are respectively connected with the analog-to-digital conversion module; the precise voltage transformer measures the three-phase voltage effective value and converts the three-phase voltage effective value into an analog signal of voltage; the precise current transformer measures the effective value of the three-phase current and converts the effective value of the three-phase current into an analog signal of the current; the input port of the DSP is connected with a precision voltage transformer, the frequency of the measured voltage signal is used as a frequency signal of a power grid, and the output port of the DSP is connected with an analog-to-digital conversion module;
the analog-to-digital conversion module respectively converts the analog signals into digital signals;
and the detection processing module is used for carrying out voltage sag detection on the digital signal.
Preferably, the precision voltage transformer comprises a current-limiting resistor and a sampling resistor; the current-limiting resistor is a primary side resistor of the precision voltage transformer, and the sampling resistor is a secondary side resistor of the precision voltage transformer.
Preferably, the precision current transformer comprises a current-limiting resistor and a sampling resistor; the current limiting resistor is a primary side resistor of the precision current transformer, and the sampling resistor is a secondary side resistor of the precision current transformer.
Preferably, the analog-to-digital conversion module includes a phase-locked loop circuit and an analog-to-digital converter; the signal output port of the phase-locked loop circuit is connected with the signal input port of the analog-to-digital converter, and the analog-to-digital conversion module converts analog signals into digital signals respectively through the phase-locked loop circuit and the analog-to-digital converter.
Preferably, the phase-locked loop circuit controls a start signal of the analog-to-digital converter, the phase-locked loop circuit is respectively connected with the precision voltage transformer, the precision current transformer and the DSP, and an output of the phase-locked loop circuit is used as a start signal for controlling the analog-to-digital converter after an input signal connected with the phase-locked loop circuit is processed.
Preferably, the analog-to-digital converter converts the analog signals of the voltage, the current and the frequency into digital signals through a starting signal input by a connected phase-locked loop circuit.
Preferably, the detection processing module includes a processing unit, and the processing unit performs voltage sag calculation processing on a digital signal transmitted by a connected analog-to-digital converter to obtain voltage sag characteristic quantity information.
Preferably, the detection processing module further comprises a human-computer interaction unit, the human-computer interaction unit is connected with the communication unit and is provided with a touch display screen, the voltage sag characteristic quantity information after calculation processing in the detection processing unit is displayed in real time, and the range of the voltage sag characteristic quantity value needing to be alarmed in the processing unit is set according to needs.
Preferably, the detection processing module further includes a communication unit, where the communication unit is connected to the processing unit, includes an extended ethernet interface, and can send and/or obtain voltage sag characteristic quantity information of each node of the power network in real time.
Preferably, the detection processing module further comprises an alarm, the alarm is connected with the processing unit and provided with a buzzer and/or a warning lamp for warning the voltage sag characteristic quantity information needing to be alarmed.
Compared with the prior art, the beneficial effects of the utility model are that:
the utility model provides a voltage sag monitoring device, include: the device comprises a power parameter acquisition and conversion module, an analog-to-digital conversion module and a detection processing module; the electric power parameter acquisition and conversion module, the analog-to-digital conversion module and the detection processing module are sequentially connected, the electric power parameter acquisition and conversion module acquires signals of three-phase voltage effective values, current effective values and frequency, converts the three-phase voltage effective values and the current effective values into analog signals of voltage and current respectively, filters higher harmonics in the analog signals, the analog-to-digital conversion module converts the analog signals of the voltage, the current and the frequency into digital signals, and the detection processing module detects voltage sag of the digital signals. The utility model provides a simple structure, real-time update are fast and the higher voltage sag detection device of precision, can be in real time accurate quick detection and show voltage sag characteristic quantity information, effectively shorten electric energy quality real-time detection's time.
Drawings
Fig. 1 is a schematic structural diagram of a voltage sag monitoring device provided by the present invention.
Detailed Description
The utility model provides a simple structure, the high voltage sag monitoring device of real-time update precision, include:
the device comprises an electric power parameter acquisition and conversion module, an analog-to-digital conversion module and a detection processing module, wherein the electric power parameter acquisition and conversion module, the analog-to-digital conversion module and the detection processing module are sequentially connected; the electric power parameter acquisition and conversion module comprises a precision voltage transformer, a current transformer and a DSP; the input ports of the precision voltage transformer and the precision current transformer are respectively connected with the three-phase input end of the power grid, and the output ends of the precision voltage transformer and the precision current transformer are respectively connected with the analog-to-digital conversion module; the precise voltage transformer measures the three-phase voltage effective value and converts the three-phase voltage effective value into an analog signal of voltage; the precise current transformer measures the effective value of the three-phase current and converts the effective value of the three-phase current into an analog signal of the current; the input port of the DSP is connected with a precision voltage transformer, the frequency of the measured voltage signal is used as a frequency signal of a power grid, and the output port of the DSP is connected with an analog-to-digital conversion module; the analog-to-digital conversion module respectively converts the analog signals into digital signals; and the detection processing module is used for carrying out voltage sag detection on the digital signal.
The utility model provides a structure complicacy, the slow problem of real-time update nature that current voltage sag apparatus exists.
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the embodiments of the present invention are clearly described below with reference to the accompanying drawings in the embodiments of the present invention.
Fig. 1 is a schematic structural diagram of a voltage sag monitoring device provided by the present invention. As shown in fig. 1, a voltage sag monitoring device includes:
the system comprises an electric power parameter acquisition and conversion module 11, an analog-to-digital conversion module 12 and a detection processing module 13, wherein the electric power parameter acquisition and conversion module 11, the analog-to-digital conversion module 12 and the detection processing module 13 are sequentially connected;
the electric power parameter acquisition and conversion module comprises a precision voltage transformer, a current transformer and a DSP; the input ports of the precision voltage transformer and the precision current transformer are respectively connected with the three-phase input end of the power grid, and the output ends of the precision voltage transformer and the precision current transformer are respectively connected with the analog-to-digital conversion module; the precision voltage transformer measures the three-phase voltage effective value, and converts the three-phase voltage effective value into a voltage analog signal under the condition that the precision is 0.5 level; the precision current transformer measures the effective value of the three-phase current, and converts the effective value of the three-phase current into an analog signal of the current under the condition that the precision is 0.5 level; the input port of the DSP is connected with a precision voltage transformer, the frequency of the measured voltage signal is used as a frequency signal of a power grid, higher harmonics in analog signals of the voltage, the current and the frequency are filtered, and the output port of the DSP is connected with an analog-to-digital conversion module; the analog-to-digital conversion module respectively converts the analog signals into digital signals; and the detection processing module is used for carrying out voltage sag detection on the digital signal.
Specifically, the power parameter acquisition and conversion unit comprises 3 precise voltage transformers and 3 precise current transformers, each phase voltage and current of the power grid are measured independently in real time, the precision of each precise voltage transformer and the precision of each precise current transformer are both 0.5 grade, and the types of the transformers can be selected according to installation sites and bus voltage grades; and converting the three-phase voltage effective value into a square wave signal, connecting the square wave signal to a high-speed input port of the DSP, and measuring the frequency signal of the power grid in real time.
On the basis of the embodiment, the precision voltage transformer comprises a current limiting resistor and a sampling resistor; the current-limiting resistor is a primary side resistor of the precision voltage transformer, and the sampling resistor is a secondary side resistor of the precision voltage transformer.
On the basis of the embodiment, the precision current transformer comprises a current limiting resistor and a sampling resistor; the current limiting resistor is a primary side resistor of the precision current transformer, and the sampling resistor is a secondary side resistor of the precision current transformer.
On the basis of the above embodiment, the analog-to-digital conversion module includes a phase-locked loop circuit and an analog-to-digital converter; the signal output port of the phase-locked loop circuit is connected with the signal input port of the analog-to-digital converter, and the analog-to-digital conversion module converts analog signals into digital signals respectively through the phase-locked loop circuit and the analog-to-digital converter.
On the basis of the above embodiment, the phase-locked loop circuit controls the start signal of the analog-to-digital converter, the phase-locked loop circuit is respectively connected with the precision voltage transformer, the precision current transformer and the DSP, and the output is used as the start signal for controlling the analog-to-digital converter after the connected input signal is processed.
On the basis of the above embodiment, the analog-to-digital converter converts the analog signals of the voltage, the current and the frequency into digital signals through the starting signal input by the connected phase-locked loop circuit.
Specifically, the phase-locked loop circuit may be composed of a phase-locked loop chip CD4046 and a frequency divider CD4040, and the obtained voltage, current and frequency signals start the analog-to-digital converter once when the phase-locked loop circuit generates a frequency doubling signal of 50 Hz; the analog-to-digital converter can be AD7606, realizes 8-channel real-time sampling, and outputs voltage, current and frequency digital signals.
On the basis of the above embodiment, the detection processing module includes a processing unit, and the processing unit performs voltage sag calculation processing on a digital signal transmitted by a connected analog-to-digital converter to obtain voltage sag characteristic quantity information.
On the basis of the embodiment, the detection processing module further comprises a human-computer interaction unit, the human-computer interaction unit is connected with the communication unit and is provided with a touch display screen, the voltage sag characteristic quantity information after calculation and processing in the detected processing unit is displayed in real time, and the range of the voltage sag characteristic quantity value needing to be alarmed in the processing unit is set according to needs. The man-machine interaction unit can be a DMT48270 touch display screen according to requirements, and real-time detection information of the voltage sag characteristic quantity is displayed.
On the basis of the above embodiment, the detection processing module further includes a communication unit, and the communication unit is connected to the processing unit, includes an extended ethernet interface, and can send and/or acquire voltage sag characteristic quantity information of each node in real time through a network, thereby improving the intelligent degree and the safety pre-warning function.
On the basis of the embodiment, the detection processing module further comprises an alarm, the alarm is connected with the processing unit and is provided with a buzzer and/or a warning lamp for warning the voltage sag characteristic quantity information needing to be warned.
Specifically, the processing unit may be an STM32F407ZGT6 chip, an algorithm of the dq conversion method is implemented according to a circuit structure solidified in the chip, and the processing unit operates a voltage sag calculation algorithm based on the obtained digital signals of the voltage, the current, and the frequency, and outputs the voltage sag characteristic amount information.
Specifically, the voltage sag characteristic quantity information includes characteristic quantity information such as a voltage sag amplitude, a voltage phase jump, a sag initial detection delay, a sag amplitude detection delay, and the like.
It is to be understood that the embodiments described are only some of the embodiments of the present invention, and not all of them. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.
The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. While the various aspects of the embodiments are presented in drawings, the drawings are not necessarily drawn to scale unless specifically indicated.
The above description is only exemplary of the invention and is not intended to limit the invention, and any modifications, equivalent alterations, improvements and the like which are made within the spirit and principle of the invention are all included in the scope of the claims which are appended hereto.
Claims (10)
1. A voltage sag monitoring device, comprising: the device comprises an electric power parameter acquisition and conversion module, an analog-to-digital conversion module and a detection processing module, wherein the electric power parameter acquisition and conversion module, the analog-to-digital conversion module and the detection processing module are sequentially connected;
the electric power parameter acquisition and conversion module comprises a precision voltage transformer, a current transformer and a DSP; the input ports of the precision voltage transformer and the precision current transformer are respectively connected with the three-phase input end of the power grid, and the output ends of the precision voltage transformer and the precision current transformer are respectively connected with the analog-to-digital conversion module; the precise voltage transformer measures the three-phase voltage effective value and converts the three-phase voltage effective value into an analog signal of voltage; the precise current transformer measures the effective value of the three-phase current and converts the effective value of the three-phase current into an analog signal of the current; the input port of the DSP is connected with a precision voltage transformer, the frequency of the measured voltage signal is used as a frequency signal of a power grid, and the output port of the DSP is connected with an analog-to-digital conversion module;
the analog-to-digital conversion module respectively converts the analog signals into digital signals;
and the detection processing module is used for carrying out voltage sag detection on the digital signal.
2. The voltage sag monitoring device according to claim 1, wherein the precision voltage transformer comprises a current limiting resistor and a sampling resistor;
the current-limiting resistor is a primary side resistor of the precision voltage transformer, and the sampling resistor is a secondary side resistor of the precision voltage transformer.
3. The voltage sag monitoring device according to claim 1, wherein the precision current transformer comprises a current limiting resistor and a sampling resistor;
the current limiting resistor is a primary side resistor of the precision current transformer, and the sampling resistor is a secondary side resistor of the precision current transformer.
4. The voltage sag monitoring device according to claim 1, wherein the analog-to-digital conversion module comprises a phase-locked loop circuit and an analog-to-digital converter;
the signal output port of the phase-locked loop circuit is connected with the signal input port of the analog-to-digital converter,
the analog-to-digital conversion module converts analog signals into digital signals respectively through a phase-locked loop circuit and an analog-to-digital converter.
5. The voltage sag monitoring device according to claim 4, wherein the phase-locked loop circuit controls an enable signal of the analog-to-digital converter,
and the phase-locked loop circuit is respectively connected with the precision voltage transformer, the precision current transformer and the DSP, and the output of the phase-locked loop circuit is used as a starting signal for controlling the analog-to-digital converter after the connected input signal is processed.
6. The voltage sag monitoring device according to claim 4, wherein the analog-to-digital converter converts the analog voltage, current, and frequency signals into digital signals by an enable signal input by a connected phase-locked loop circuit.
7. The voltage sag monitoring device according to claim 1, wherein the detection processing module comprises a processing unit,
and the processing unit calculates and processes voltage sag through the digital signals transmitted by the connected analog-to-digital converter to obtain the characteristic quantity information of the voltage sag.
8. The voltage sag monitoring device according to claim 1, wherein the detection processing module further comprises a human-computer interaction unit,
the man-machine interaction unit is connected with the communication unit and is provided with a touch display screen, the voltage sag characteristic quantity information after calculation and processing in the detected processing unit is displayed in real time, and the range of the voltage sag characteristic quantity value needing to be alarmed in the processing unit is set according to needs.
9. The voltage sag monitoring device according to claim 1, wherein the detection processing module further comprises a communication unit,
the communication unit is connected with the processing unit, comprises an extended Ethernet interface and can send and/or acquire the voltage sag characteristic quantity information of each node of the power network in real time.
10. The voltage sag monitoring device according to claim 1, wherein the detection processing module further comprises an alarm,
the alarm is connected with the processing unit and is provided with a buzzer and/or a warning lamp for warning the voltage sag characteristic quantity information needing to be alarmed.
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| CN202021611977.4U CN214011350U (en) | 2020-08-06 | 2020-08-06 | Voltage sag monitoring device |
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| CN202021611977.4U CN214011350U (en) | 2020-08-06 | 2020-08-06 | Voltage sag monitoring device |
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| CN214011350U true CN214011350U (en) | 2021-08-20 |
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