Vitrek PA900 Power Analyzer Technical Attributes

Vitrek PA900 Power Analyzer Technical Attributes Encompasses All Aspects of  Theoretical Power Analysis

Vitrek PA900 Power Analyzer Technical Attributes encompasses Power Factor (PF) Determination

Vitrek PA900 Power Analyzer Technical Attributes encompasses Power Factor (PF) determination. Consider Power Factor Accuracy, for a non-unity power factor due to non-linearity in the load: Max. Error = PF – ((W + the AC Floor Adder portion with K = 0.3) / (VA + the AC Floor Adder portion with K = 1.0).

Vitrek PA900 Power Analyzer Technical Attributes encompasses Voltage and Current Sampling

Vitrek PA900 Power Analyzer Technical Attributes encompasses Voltage and Current Sampling at a rate of 245KSPS nominal (900KSPS nominal for W channels) with 22 & 24 bit resolution.

Vitrek PA900 Power Analyzer Technical Attributes encompasses Synchronization

Vitrek PA900 Power Analyzer Technical Attributes encompasses Synchronization accuracy where both Voltage and Current measurement periods and rates are adjusted such that there is synchronization to within <±5ppm of an integer number of fundamental cycles.

Vitrek PA900 Power Analyzer Technical Attributes encompasses Asynchronization accuracy where both measurement periods and rates are adjusted such that there is no synchronization to a >500Hz periodic signal content other than the fundamental frequency.

Vitrek PA900 Power Analyzer Technical Attributes takes into consideration Jitter

The Vitrek PA 900 utilizes deliberate Jitter Sampling such that the relative time of any given sample in a measurement period varies by up to ± ½ a sample period but the net effect is zero when averaged over the entire measurement period. The jitter is quasi-random such that there are no sub-measurement period periodic elements within the actual sampling rate.

The Vitrek VA900 employees V & A Sampling

 The Voltage and Current of each channel are sampled to ensure that the signals at the terminals are sampled nominally within <±5ns of each other (equivalent of ±0.0018° per KHz phase)

Effective Sampling Rate

The Effective Sampling Rate, including the effects of jittered sampling, which establishes the overall effective sampling rate for analysis of periodic signals within a measurement period is 384MSPS.

Vitrek PA900 Power Analyzer Technical Attributes uses Phase and Frequency Compensation

No phase or frequency compensation of samples is performed after sampling. Each signal is independently sampled to produce synchronous sampling at the terminals of the PA900.

Non-Harmonic Analysis

The voltage and current samples are used to perform mathematical analysis of the signals to produce the various non-harmonic measurement results. The precision of the calculations within each measurement period is at least 32 bits for non-accumulated data (e.g. peak measurements) and at least 64 bits for accumulated data (e.g. DC and average rectifi­ed measurements) and at least 96 bits for accumulated squared or cross-multiplied data (e.g. RMS and power measurements). Post-measurement calculations are performed using 32 bit precision, except for integrated data which is performed using 64 bit precision.

Harmonic Results

Amplitude and phase for each harmonic for every confi­gured signal is combined as needed to produce measurement results which includes Volts, Amps, Watts, VAR, PF, Load (fundamental), Inter-phase Phase (fundamental), Inter-phase Volts (fundamental), Neutral Amps (fundamental), THD (relative to fundamental) and THD (relative to AC RMS).

Historical Data Collection

The PA900 always maintains a record of all non-harmonic results and a selection of the harmonic results internally in volatile memory. This record automatically extends up to 397 days.

Vitrek PA900 Data Logging

The user may select up to 16 measurement results to data log at configured intervals of time to a drive attached to the front panel USB port.

Vitrek PA900 Cycle View

The actual single cycle voltage and current periodic waveforms are provided for frequencies up to the maximum harmonic fundamental frequency.

Vitrek PA900 Scope View

The actual voltage and current waveforms can be captured in a manner similar to that in a digital sampling oscilloscope. Signals can be viewed and confi­gured in the SCOPE screen or interrogated and confi­gured via an interface. Time base, trigger and trigger position, scale and offset are all selectable.

Vitrek PA900 Front Panel Results Screens

The following results screens are available at the front panel of the PA900 using a single ‘button’ on the screen to select which is being displayed—POWER DATA Screen: This displays V, A, W, VA, VAR and PF data for any selected channel or the totals for any VPA.

Vitrek PA900 CUSTOM DATA Screen

The user may build a custom data screen showing any of the available results from any of the channels and/or analyzers.

Vitrek PA900 HARMONICS Screen

This displays a bar chart showing all available harmonics for any selected signal (V or A) and also a listing of any 8 harmonics numerical amplitudes and phases (scrollable within the available harmonics). If a set of limits is available and has been enabled for the selected signal, the bar chart displays a limit line and also displays any failing harmonics as a red color above the limit.

Vitrek PA900 VECTORS Screen

This displays a polar chart graphically showing the fundamental voltage and current vectors for a selected channel or analyzer

Front Panel USB Drive Interface

The PA900 can interface to an external drive (e.g. a ‘thumb’ or ‘Flash’ drive) via the front panel USB port of the PA900. This provides the following capabilities – the ability to import or export a con­figuration of the PA900, the ability to import or export a custom data screen de­finition, the ability to data log to a ­le, the ability to export a ‘screen shot’ from the PA900 and the ability to import or export a set of harmonics limits.

Vitrek PA900 Power Analyzer Interfaces

LAN (Ethernet), Serial (RS232), USB (Client) and USB (Host – Front Panel) for mass data storage

Vitrek PA900 Power Analyzer Technical Attributes provides a Comprehensive Product Con­figuration Guide

To build a product con­figuration code for the PA900 simply add the 2 digit Channel Card codes (comma separated) in the order desired, for up to a maximum of 4 channel cards. The MT type card is available in slot 4 only. For example a PA900AD, AD, WX, WX configures a PA900 with an AD type card in slots 1 and 2 and a WX type card in slots 3 and 4. To add advanced computational options, add one or both codes after the last channel card.

Vitrek PA900 Advanced Computational Options

• Code Option “5” H500 500 Harmonics Capability
• Code Option “E” EN61000 Compliance Computations

For example a PA900SH,AX,MT5E confi­gures a PA900 with an SH type card in slot 1, an AX type card in slot 2, an MT type card in slot 4 (MT fi­ts in slot 4 only, so slot 3 is left blank) and the H500 and EN61000 advanced computational options. For units with all identical cards a product con­figuration code is not required. However, orders for units with different type channel cards require a con­figuration code to establish the desired location of each channel card.

Link to Power Quality Explained