Metering and Energy Monitoring

The ADE9000 is a highly accurate, fully integrated, multiphase energy and power quality monitoring device. Superior analog performance and a digital signal processing (DSP) core enable accurate energy monitoring over a wide dynamic range. An integrated high end reference ensures low drift over temperature with a combined drift of less than ±25 ppm/°C maximum for the entire channel including a programmable gain amplifier (PGA) and an analog-to-digital converter (ADC).

The ADE9000 offers complete power monitoring capability by providing total as well as fundamental measurements on rms, active, reactive, and apparent powers and energies. Advanced features such as dip and swell monitoring, frequency, phase angle, voltage total harmonic distortion (VTHD), current total harmonic distortion (ITHD), and power factor measurements enable implementation of power quality measurements. The ½ cycle rms and 10 cycle rms/12 cycle rms, calculated according to IEC 61000-4-30 Class S, provide instantaneous rms measurements for real-time monitoring.

The ADE9000 offers an integrated flexible waveform buffer that stores samples at a fixed data rate of 32 kSPS or 8 kSPS, or a sampling rate that varies based on line frequency to ensure 128 points per line cycle. Resampling simplifies fast Fourier transform (FFT) calculation of at least 50 harmonics in an external processor.

The ADE9000 simplifies the implementation of energy and power quality monitoring systems by providing tight integration of acquisition and calculation engines. The integrated ADCs and DSP engine calculate various parameters and provide data through user accessible registers or indicate events through interrupt pins. With seven dedicated ADC channels, the ADE9000 can be used on a 3-phase system or up to three single-phase systems. It supports current transformers (CTs) or Rogowski coils for current measurements. A digital integrator eliminates a discrete integrator required for Rogowski coils.

The ADE9000 absorbs most complexity in calculations for a power monitoring system. With a simple host microcontroller, the ADE9000 enables the design of standalone monitoring or protection systems, or low cost nodes uploading data into the cloud.

Note that throughout this data sheet, multifunction pins, such as CF4/EVENT/DREADY, are referred to either by the entire pin name or by a single function of the pin, for example, EVENT, when only that function is relevant.

Applications

• Energy and power monitoring
• Power quality monitoring
• Protective devices
• Machine health
• Smart power distribution units
• Polyphase energy meters

The ADE9078 is a highly accurate, fully integrated energy metering device. Interfacing with both current transformer (CT) and Rogowski coil sensors, the ADE9078 enables users to develop a 3-phase metrology platform, which achieves high performance for Class 1 up to Class 0.2 meters.

The ADE9078 integrates seven high performances ADCs and a flexible DSP core. An integrated high end reference ensures low drift over temperature with a combined drift of less than ±25 ppm/°C maximum per channel, each of which includes a programmable gain amplifier (PGA) and ADC.

The ADE9078 offers an integrated flexible waveform buffer that stores samples at a fixed data rate or a sampling rate that varies based on line frequency to ensure 64 points per line cycle. These two options make it easy to implement harmonic analysis in an external processor according to IEC 61000-4-7.

Two power modes are provided to enable detection of meter tampering: PSM2 uses a low power comparator to compare current channels to a threshold and indicates whether it is exceeded on the IRQ0 and IRQ1 outputs; PSM1 enables fast measurement of current and voltage rms (xVRMS and xIRMS), active power, and VAR during a tamper.

The ADE9078 allows advanced and highly accurate energy measurements, enabling one platform to cover a wide range of meters, through a combination of various high end metrology features and superior analog performance.

Applications

• Polyphase meters
• Power quality monitoring
• Protective device

The ADE7880 is high accuracy, 3-phase electrical energy measurement IC with serial interfaces and three flexible pulse outputs. The ADE7880 device incorporates second-order sigma-delta (Σ-Δ) analog-to-digital converters (ADCs), a digital integrator, reference circuitry, and all of the signal processing required to perform the total (fundamental and harmonic) active, and apparent energy measurements, rms calculations, as well as fundamental-only active and reactive energy measurements. In addition, the ADE7880 computes the rms of harmonics on the phase and neutral currents and on the phase voltages, together with the active, reactive, and apparent power, and the power factor and harmonic distortion on each harmonic for all phases. Total harmonic distortion plus noise (THD + N) is computed for all currents and voltages. A fixed function digital signal processor (DSP) executes this signal processing. The DSP program is stored in the internal ROM memory.

The ADE7880 is suitable for measuring active, reactive, and apparent energy in various 3-phase configurations, such as wye or delta services with both three and four wires. The ADE7880 provides system calibration features for each phase, that is, rms offset correction, phase calibration, and gain calibration. The CF1, CF2, and CF3 logic outputs provide a wide choice of power information: total active powers, apparent powers, or the sum of the current rms values, and fundamental active and reactive powers.

Figure 1: High Common-Mode Voltage Current Monitor (All Connections and Decoupling Not Shown)

Lithium ion (Li-Ion) battery stacks contain a large number of individual cells that must be monitored correctly in order to enhance the battery efficiency and prolong the battery life. The 6-channel AD7280A devices in the circuit shown in Figure 1 act as the primary monitor providing accurate measurement data to the Battery Management Controller (BMC).

The AD7280A contains an internal ±3 ppm reference that allows a cell voltage measurement accuracy of ±1.6 mV. The ADC resolution is 12 bits and allows conversion of up to 48 cells within 7 μs.

The AD7280A, which resides on the high voltage side of the Battery Management System (BMS) has a daisy-chain interface, which allows up to eight AD7280A’s to be stacked together and allows for 48 Li-Ion cell voltages to be monitored. Adjacent AD7280A's in the stack can communicate directly, passing data up and down the stack without the need for isolation. The AD7280A master device on the bottom of the stack uses the SPI interface to communicate with the BMC, and it is only at this point that high voltage galvanic isolation is required in order to protect the low-voltage side of the BMS. The ADuM1201 digital isolator and the ADuM5401 isolator with integrated dc-to-dc converter combine to provide the required six channels of isolation in a compact and cost effective solution.

Figure 1. AD7280A Daisy-Chain Configuration Circuit with Isolation (Simplified Schematic: All Connections and Decoupling Not Shown)