Maxim公司的MAXQ3180是专用的电测量前端(AFE),可以测量多相负载的多相电压,电流,功率,能量以及其它参数. MAXQ3180和三相/三线,三相/四线和其它三相服务兼容,能测量每相和三相组合的有用功率和能量(kWh), 每相和三相组合的无功功率和能量, 每相和三相组合的表观功率和能量,零线的电流测量.精密的片内基准电压2.048V,主要用在三相多功能电表.本文介绍了MAXQ3180主要特性,方框图, 典型应用电路图和采用MAXQ3180 AFE电表参考设计主要特性, 三相电表方框图和完整的电路图和材料清单.
The MAXQ3180 is a dedicated electricity measurement front-end that collects and calculates polyphase voltage, current, power, energy, and many other metering and power-quality parameters of a polyphase load. The computed results can be retrieved by an external master through the on-chip serial peripheral interface (SPI™) bus. This bus is also used by the external master to configure the operation of the MAXQ3180 and monitor the status of operations.
The MAXQ3180 performs voltage and current measurements using an integrated ADC that can measure up to seven external differential signal pairs. An eighth differential signal pair is used to measure the die temperature.
An internal amplifier automatically adjusts the current channel gain to compensate for low-current channel-signal levels.
MAXQ3180主要特性:
♦ Compatible with 3-Phase/3-Wire, 3-Phase/4-Wire, and Other 3-Phase Services
♦ Active Power and Energy of Each Phase and Combined 3-Phase (kWh), Positive and Negative
♦ Reactive Power and Energy of Each Phase and Combined, Positive and Negative
♦ Apparent Power and Energy of Each Phase and Combined 3-Phase
♦ Neutral Line Current Measurement
♦ Line Frequency (Hz)
♦ Power Factors
♦ Voltage Phasor Angles
♦ Phase Sequence Indication
♦ Phase Voltage Absence Detection
♦ Voltage and Current Harmonic Measurement
♦ Fundamental and Total Power and Energy
♦ Two Pulse Outputs: Configurable for Active, Reactive, and Apparent Powers
♦ Programmable Pulse Widths
♦ Programmable No-Load Current Threshold
♦ Programmable Meter Constants
♦ Programmable Thresholds for Undervoltage and Overvoltage Detection
♦ Programmable Threshold for Overcurrent Detection
♦ Amp-Hours in Absence of Voltage Signals
♦ On-Chip Digital Temperature Sensor
♦ Precision Internal Voltage Reference 2.048V (30ppm/°C typical), Also Supports An External Voltage Reference
♦ Supports Software Meter Calibration
♦ Up to 3-Point Multipoint Calibration to Compensate for Transducer Nonlinearity
♦ Power-Fail Detection
♦ Bidirectional Reset Input/Output
♦ SPI-Compatible Serial Interface with Interrupt Request (IRQ) Output
♦ Single 3.3V Supply, Low Power (35mW typical)
MAXQ3180应用:
3-Phase Multifunction Electricity Meters
图1.MAXQ3180方框图
图2.MAXQ3180典型应用电路图
采用MAXQ3180/MAXQ3183 AFE电表参考设计
Reference design for an energy meter using the MAXQ3180/MAXQ3183 AFEs
电表参考设计主要指标:
The reference design supports 3-phase four wires only:
AC conditions: 50Hz/60Hz, 220V,9A²
Meter constant: 6400
Meter accuracy: class 0.5s active and class 2 reactive
Serial (PC) communication baud rate: 1200/9600/57600/115200
The reference-design meter starts running automatically upon power-up and will display various information on the board’s LCD. The first item displayed is the device name (i.e., the MAXQ3180 or MAXQ3183), then the RS-232 baud rate, followed by various power and energy parameters (voltage RMS, current RMS, total power factor, total kilowatt-hour usage since last power-on). This information automatically rotates continually with an update rate of one parameter per second. More energy and power parameters can be retrieved and displayed by the PC software.
The meter communicates with a PC through an RS-232 serial port, which is hidden inside the meter case. To access the serial port, open the meter case. Be sure to power off the AC supply before proceeding. Note that the MAXQ3180 reference design supports infrared communication in hardware, but the firmware (MAXQ2000 code) support for this feature has not been implemented as of this writing.
图3.MAXQ3180三相电表外形图
图4.MAXQ3180三相电表方框图
图5.MAXQ3180三相电表电路图:热板中的AFE部分
图6.MAXQ3180三相电表电路图:热板中的IV接口部分
图7.MAXQ3180三相电表电路图:热板中的电源管理部分
图8.MAXQ3180三相电表电路图:热板中隔离部分
图9.MAXQ3180三相电表电路图:热板中电源和通信部分
图10.MAXQ3180三相电表电路图: 冷板中MCU和LCD部分
三相电表中冷板材料清单(BOM):
详情请见:
http://datasheets./en/ds/MAXQ3180.pdf
和
http://pdfserv./en/an/AN4663.pdf 声明：本网站原创内容，如需转载，请注明出处；本网站转载的内容（文章、图片、视频）等资料版权归原网站所有。如我们采用了您不宜公开的文章或图片，未能及时和您确认，避免给双方造成不必要的经济损失，请电邮联系我们，以便迅速采取适当处理措施；欢迎投稿，邮箱：editors@。
|
