WO2002073221A2 - Messwert-erfassungs- und -verarbeitungseinheit für kleine messsignale - Google Patents
Messwert-erfassungs- und -verarbeitungseinheit für kleine messsignale Download PDFInfo
- Publication number
- WO2002073221A2 WO2002073221A2 PCT/DE2002/000808 DE0200808W WO02073221A2 WO 2002073221 A2 WO2002073221 A2 WO 2002073221A2 DE 0200808 W DE0200808 W DE 0200808W WO 02073221 A2 WO02073221 A2 WO 02073221A2
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- measurement
- processing unit
- value acquisition
- signals
- measuring circuit
- Prior art date
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D18/00—Testing or calibrating apparatus or arrangements provided for in groups G01D1/00 - G01D15/00
- G01D18/002—Automatic recalibration
- G01D18/006—Intermittent recalibration
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D3/00—Indicating or recording apparatus with provision for the special purposes referred to in the subgroups
- G01D3/02—Indicating or recording apparatus with provision for the special purposes referred to in the subgroups with provision for altering or correcting the law of variation
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/0046—Arrangements for measuring currents or voltages or for indicating presence or sign thereof characterised by a specific application or detail not covered by any other subgroup of G01R19/00
- G01R19/0053—Noise discrimination; Analog sampling; Measuring transients
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R35/00—Testing or calibrating of apparatus covered by the other groups of this subclass
- G01R35/005—Calibrating; Standards or reference devices, e.g. voltage or resistance standards, "golden" references
Definitions
- the invention relates to a measurement value acquisition and processing unit for small signals, which is formed by a measuring circuit, which has at least one scanning unit, an A / D converter and digital signal processing, the scanning unit for scanning one serves measurement signal, the A / D converter is provided for digitizing the sample values and the digital signal processing is used for processing the digitized sample values which, in addition to the useful value to be recorded from the measurement signal, have interference components as a result of interference signals, for example Noise and coupling into the measuring circuit.
- a classic example of the required precise acquisition of measurement signals is electronic motor protection, in which the motor currents serve as input variables for a thermal motor model.
- motor protection with a high setting range of e.g. 1:10, which indicates the ratio of the minimum rated current to the maximum rated current of the motor.
- the starting current of the motor can be ten times the nominal current, so that a dynamic range of 1: 100 is required for the analog / digital converter.
- the invention is therefore based on the object of creating a measurement value acquisition and processing unit of the type mentioned above, which inexpensively enables a large dynamic range for the acquisition of measurement variables.
- a measurement value acquisition and processing unit with the features according to claim 1.
- a switching element is provided, by means of which an electrical connection of the measuring circuit to its reference potential AGND can be established, in which, without coupling a measuring signal into the measuring circuit, only any interference signals that may be present occur in the measuring circuit and are detected thereby.
- the digital signal processing is also used for numerical compensation, in which useful values of the measurement signal, which have interference components, are compensated for with interference components recorded in a time-relevant, isolated manner.
- this measurement value acquisition and processing unit is that the interference components which falsify the useful signal are measured in isolation in a simple manner. If both measurements take place, on the one hand the measurement for recording the utility value and on the other hand the measurement for recording the interference component takes place almost simultaneously or with a negligible small time interval ' , so the interference component in the detected utility value can be compensated for in digital signal processing.
- the scanning unit has a multiplexer which is used for time-division scanning of three measurement signals executed by current sensors.
- the current sensors are designed as current transformers, the measurement signals on the output side of which are at a common reference potential and if four inputs are available in the multiplexer for coupling the measurement signals and the reference potential.
- the switching element is implemented in the multiplexer so that the short-circuit connection in the measuring circuit to the reference potential is established.
- 1 shows an inventive measurement value acquisition and processing unit for acquiring a measurement signal
- FIG. 2 shows a further embodiment of the measurement value acquisition and processing unit according to the invention for acquiring several measurement variables, e.g. the currents of an engine.
- FIG. 1 shows a measurement value acquisition and processing unit 5 according to the invention.
- This is formed by a measuring circuit which has at least one scanning unit 6, an analog / digital converter 7 and digital signal processing 8.
- the scanning unit 6 is used to scan a time-varying measurement signal x (t) to be detected, which can be, for example, a current, a voltage or a temperature and which is supplied by a sensor 9.
- the digital sample values are further processed in the digital signal processing 8.
- the digital samples can contain interference components as a result of interference signals, for example noise and coupling into the measurement circuit.
- the coupling in of the measurement signal x (t) is canceled by switching over the switching element 10, so that only any interference signals that may be present occur in the measuring circuit and are detected thereby.
- the interference components have to be recorded in a time-relevant manner to the recorded utility values, ie with the least possible time delay.
- the detection of all interference signals is all the more comprehensive and accurate, the closer the switching connection is to the point at which the measurement signal x (t) is coupled into the measurement value acquisition and processing unit 5, eg between the input terminals for the measurement signal x (t).
- the digital signal processing 8 is used for numerical compensation, in which useful values of the measurement signal x (t) which have interference components are compensated for with interference components which are detected in a time-related, isolated manner.
- FIG. 2 shows a further embodiment of a measurement value acquisition and processing unit according to the invention.
- the three-phase current load in the phase conductors L1, L2, L3 is measured, into which current transformers 11 are connected as current sensors, the secondary winding of which is also connected is burdened with a resistor 12.
- a voltage U ⁇ (t), u (t), u 3 (t) proportional to the respectively detected phase current istrom (t), i 2 (t), i 3 (t) is consequently present at the three resistors 12, with t the variable "time" is marked.
- the three resistors 12 are interconnected in the common circuit point 13, which has a predetermined reference potential, here designated AGND.
- the voltages u ⁇ (t), u 2 (t), u 3 (t) applied to the resistors 12 with respect to this reference potential AGND are fed to inputs of a measuring and processing unit 5.
- This comprises a measuring circuit with a multiplexer in a scanning unit 6, which has inputs ei, e, e 3 , eo, an analog / digital converter 7 and digital signal processing 8.
- the multiplexer reaches over its inputs ei, e 2 , e 3 in a predetermined multiplex order, for example 1,2,3 the voltages u ⁇ (t), u 2 (t), u 3 (t) one after the other.
- the further input e 0 is present in the multiplexer and is optionally connected inside or outside the measurement value acquisition and processing unit 5 via an additional measurement channel with a resistor 14 to the reference potential AGND of the circuit point 13.
- the resistor 14 corresponds to the above-mentioned resistor 12.
- the measured value acquisition and processing unit for detecting the thermal load, e.g. an engine is based on the requirement that the thermal load
- Current transformers 11 must be inexpensive and accordingly small. This can be achieved by current sensors 11 with correspondingly small measurement signals x (t), the height of which are in the range of interference signals, e.g. noise, overcoupling. Interference signals that are injected in the area of the current sensors 11 can be compensated for with little effort by appropriate wiring.
- the present invention aims to compensate for the injected interference signals occurring in the measurement value acquisition and processing unit 5. It is assumed that the interference signals with which the equivalent current measurement values u ⁇ (t), u 2 (t), u 3 (t) are applied can be measured separately with a small time offset, so that the numerical compensation for the calculation of the thermal load required exact useful values can be determined excluding interference.
- the additional input e 0 to which an additional measuring channel with the resistor 14, which is connected to the reference potential AGND, can be excluded, is used to detect the separate interference components i 0 .
- the multiplexer, ie its switching element 10 the return line with the reference potential AGND can be connected to the measuring circuit via phase 0 with the resistor 14.
- the connection to one of the inputs ei, e 2 , e 3 is interrupted, so that no measuring voltage u ⁇ (t), u 2 (t), u 3 (t) is coupled in, but only interference signals i 0 occur in the measuring circuit and are recorded.
- the sampled values recorded in each of the phases 1, 2, 3, 0 are forwarded from the multiplexer 6 to the analog / digital converter 7 for digitization and finally further processed in the digital signal processing 8.
- the digital sig- nal kau 8 is designed as a microprocessor in which. the effective values of the phase currents are calculated to determine the thermal load. In the ideal case, ie without the occurrence of interference signals in, the effective value can be determined in a conventional manner using a digital measuring system for measuring the effective value using the following equation
- the effective value of the current according to the invention is determined as follows:
Abstract
Description
Claims
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP02716639A EP1368668B1 (de) | 2001-03-14 | 2002-03-06 | Messwert-erfassungs- und -verarbeitungseinheit für kleine messsignale |
CA002440774A CA2440774A1 (en) | 2001-03-14 | 2002-03-06 | Measurement value detection and processing unit for small measurement signals |
DE50200668T DE50200668D1 (de) | 2001-03-14 | 2002-03-06 | Messwert-erfassungs- und -verarbeitungseinheit für kleine messsignale |
US10/471,460 US6853180B2 (en) | 2001-03-14 | 2002-03-06 | Measured value acquisition and processing unit for small measuring signals |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE10112304.3 | 2001-03-14 | ||
DE10112304A DE10112304C1 (de) | 2001-03-14 | 2001-03-14 | Messwert-Erfassung- und -Verarbeitungseinheit für kleine Messsignale |
Publications (2)
Publication Number | Publication Date |
---|---|
WO2002073221A2 true WO2002073221A2 (de) | 2002-09-19 |
WO2002073221A3 WO2002073221A3 (de) | 2003-06-12 |
Family
ID=7677463
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/DE2002/000808 WO2002073221A2 (de) | 2001-03-14 | 2002-03-06 | Messwert-erfassungs- und -verarbeitungseinheit für kleine messsignale |
Country Status (5)
Country | Link |
---|---|
US (1) | US6853180B2 (de) |
EP (1) | EP1368668B1 (de) |
CA (1) | CA2440774A1 (de) |
DE (2) | DE10112304C1 (de) |
WO (1) | WO2002073221A2 (de) |
Families Citing this family (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE10258965B4 (de) * | 2002-12-16 | 2007-06-21 | Endress + Hauser Gmbh + Co. Kg | Vorrichtung zur Optimierung der Leistungsbilanz eines Sensors für die Bestimmung und/oder Überwachung einer physikalischen Prozessgröße eines Mediums |
DE102004050566A1 (de) * | 2004-10-15 | 2006-04-20 | Robert Bosch Gmbh | Vorrichtung zur energiesparenden Erfassung einer Betriebsgröße eines bewegbaren Elements |
US8213141B2 (en) * | 2006-01-17 | 2012-07-03 | Broadcom Corporation | Power over Ethernet electrostatic discharge protection circuit |
US8309129B2 (en) * | 2007-05-03 | 2012-11-13 | Bend Research, Inc. | Nanoparticles comprising a drug, ethylcellulose, and a bile salt |
DE102008043326B4 (de) | 2008-10-30 | 2018-03-15 | Endress+Hauser Conducta Gmbh+Co. Kg | Verfahren und Vorrichtung zur Widerstandsmessung eines von einer chemischen und/oder physikalischen Messgröße abhängigen Widerstandselements |
DE102014225769B4 (de) * | 2014-12-12 | 2016-11-10 | Ifm Electronic Gmbh | Schaltung für einen Analogsensor |
DE102015223636B4 (de) * | 2014-12-12 | 2016-11-17 | Ifm Electronic Gmbh | Schaltung für einen Analogsensor |
EP3370074B1 (de) | 2016-11-02 | 2020-03-18 | Shenzhen Goodix Technology Co., Ltd. | Verfahren zur erkennung des hintergrundrauschens eines sensors und vorrichtung dafür |
CN115951114B (zh) * | 2023-01-17 | 2023-06-23 | 上海山源电子科技股份有限公司 | 一种供电监测系统中的电流信号识别方法 |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4163940A (en) * | 1975-09-15 | 1979-08-07 | Racal Instruments Limited | Electrical measurement and noise suppression |
GB1575148A (en) * | 1976-07-07 | 1980-09-17 | Heliowatt Werke | Electrical energy meters |
DE3700368C1 (en) * | 1987-01-08 | 1988-06-01 | Rohde & Schwarz | Digital oscilloscope |
US5929628A (en) * | 1996-12-05 | 1999-07-27 | Teradyne, Inc. | Apparatus and method for performing amplitude calibration in an electronic circuit tester |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
YU47218B (sh) * | 1989-03-07 | 1995-01-31 | Zellweger Uster Ag. | Statičko električno brojilo |
DE4434318A1 (de) * | 1994-09-26 | 1996-03-28 | Forschungszentrum Juelich Gmbh | Verfahren und Einrichtung zur Meßwerterfassung und -verarbeitung |
DE4446775B4 (de) * | 1994-12-24 | 2006-07-20 | Miele & Cie. Kg | Verfahren zur Kompensation der thermischen Offsetdrift von Sensoren |
DE19533505A1 (de) * | 1995-09-04 | 1997-03-06 | Siemens Ag | Verfahren zum Kompensieren des durch eine äußere Einflußgröße verursachten Fehlverhaltes von Meßeinrichtungen |
DE19818315C1 (de) * | 1998-04-23 | 1999-09-16 | Siemens Ag | Einrichtung zum ratiometrischen Messen von Sensorsignalen |
US6392402B1 (en) * | 1998-07-30 | 2002-05-21 | Fluke Corporation | High crest factor rms measurement method |
-
2001
- 2001-03-14 DE DE10112304A patent/DE10112304C1/de not_active Expired - Fee Related
-
2002
- 2002-03-06 EP EP02716639A patent/EP1368668B1/de not_active Expired - Fee Related
- 2002-03-06 CA CA002440774A patent/CA2440774A1/en not_active Abandoned
- 2002-03-06 US US10/471,460 patent/US6853180B2/en not_active Expired - Fee Related
- 2002-03-06 DE DE50200668T patent/DE50200668D1/de not_active Expired - Fee Related
- 2002-03-06 WO PCT/DE2002/000808 patent/WO2002073221A2/de active IP Right Grant
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4163940A (en) * | 1975-09-15 | 1979-08-07 | Racal Instruments Limited | Electrical measurement and noise suppression |
GB1575148A (en) * | 1976-07-07 | 1980-09-17 | Heliowatt Werke | Electrical energy meters |
DE3700368C1 (en) * | 1987-01-08 | 1988-06-01 | Rohde & Schwarz | Digital oscilloscope |
US5929628A (en) * | 1996-12-05 | 1999-07-27 | Teradyne, Inc. | Apparatus and method for performing amplitude calibration in an electronic circuit tester |
Also Published As
Publication number | Publication date |
---|---|
EP1368668B1 (de) | 2004-07-21 |
US6853180B2 (en) | 2005-02-08 |
EP1368668A2 (de) | 2003-12-10 |
US20040095146A1 (en) | 2004-05-20 |
DE50200668D1 (de) | 2004-08-26 |
CA2440774A1 (en) | 2002-09-19 |
DE10112304C1 (de) | 2002-07-18 |
WO2002073221A3 (de) | 2003-06-12 |
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