DIGITAL INSTRUMENTS S.R.L. SPM-ETH (Synchro Phasor Meter over ETH)

Transcription

1 DIGITAL INSTRUMENTS S.R.L. SPM-ETH (Synchro Phasor Meter over ETH)

2 SPM-ETH (Synchro Phasor Meter over ETH) Digital Instruments 1 ver the years, an awareness of the criticality of the Power Grid and Orelated technologies has led to an increasing application of modern ICT solutions to traditional electrical engineering technology (Smart Grid); this is for various reasons, just to mention some: better and informed management of the consumption, caused by a growing need for expensive energy, stability requirements and certification that technologies increasingly pervasive in our daily need will work reliably around the clock. The Smart Grid easily accepts renewable and intermittent energy sources and transmits that energy without waste or loss of stability, saving money for the energy customer. Precise and real-time measurements of power system properties are a critical feature of the Smart Grid. Timesynchronized phasors are the modern way to obtain these measurements. Now a wide-area determination of the exact state of the power system in real time is possible. For this purpose, Digital Instruments has developed SPM-ETH (Synchro Phasor Meter over ETH) a device able to manage and monitor every aspect of the distribution network in different situations. The result is a more efficient, reliable, economical, and safe electrical energy transfer from generation to the consumer.

3 SPM-ETH: introduction 2 Based on previous experience in hardware and software development and implementation of some of the highest performance systems currently available worldwide, Digital Instruments has developed an apparatus able to certify the quality of the energy of a network of devices / low voltage transducers, allowing the data storage, and managing synchronization universally used technologies and communication protocols. The apparatus is a rack mountable Phasor Measurement Unit (PMU) compatible device featuring the best achievable accuracy. The synchronization system has multiple redundancy, since it uses, in addition to traditional GPS, also Ethernet with a dedicated timing protocols (PTP/IEEE 1588, NTP), external references (e.g. Rubidium), IRIG-B, certificated signals and others. SPM-ETH is compliant with the IEEE C Synchrophasor Protocol (Specification for Synchronization of Power Measurement Unit). SPM-ETH measures, through sampling of current and voltage, system (absolute) phase angle, system frequency deviation, and system time deviation. For monitoring power quality and harmonics it can measure K-factor, flicker, interruptions, and log data by time interval, or record out-of-limit events with time of occurrence. The user can set limits on any quantity. Also, an alarm contact may be activated, or a dial-up modem call initiated. About Data and Event logging, a highperformance flash memory is used. This nonvolatile memory can record revenue data, power quality, internally detected faults, alarms, internal and external events. Eight event inputs may be used to monitor external events. MAIN APPLICATIONS: Control and Monitoring of Power Measurement Unit. Certification of the energy produced by PV plants sent to the main grid. Control and Monitoring of the local grid of different environments (e.g. hospital, building) and certification of quality. FEATURES: Very high speed recording, sampling at up to 200 khz Transient fault recorder Disturbance recorder Disturbance logger Trend recording Power quality monitor Real time stability monitor Synchrophasor measurement Sequence of events recorder Online switchgear and PV/battery monitor Energy meter with peak demand Plant commissioning and diagnostic tool Electronic chart recorder

4 Transient recorder The high speed option allows for all analog inputs to be sampled synchronously up to 200 ksamples per second. Transient fault recorder The transient fault recorder is used for post-fault analysis in verifying protection and circuit breaker operations and also fault clearance times. Information about fault type, fault levels and duration are an aid to fault location and clearance. Transient and incipient faults are also quantified, to allow improvements in supply security to be made. Disturbance recorder The disturbance recorder provides information which enables improved understanding of the power network. Longer term events are monitored by the disturbance recorder. Frequency, RMS and phasor information are stored per channel. These are used to compute a wide range of power system quantities. This function is particularly useful in recording reclose sequences and power and frequency stability events. Additionally, it can be used to extend the pre- and post-fault times of a transient record. Triggers for the disturbance recorder include low frequency oscillation on the power and frequency signals. Trend recording The input and computed quantities are logged as maximum, minimum and average quantities every minute. One year s worth of data is saved by the system. This enables historical data, at a reduced sampling rate, to be retrieved for trend and power quality analysis. The data can be used to replace circular chart recorders to verify voltage regulation and balancing. Power quality monitor Voltage level and range Voltage balance Loss of supply Harmonic distortion Voltage Fluctuation and Flicker Stray Voltage Voltage Frequency 3 Stability monitor A very powerful feature of the apparatus is the ability to trigger on and record differential phasor measurements. Because the inputs are sampled with high-stability in the time domain, the absolute angle of the positive sequence voltage vector can be computed very accurately. This value is compared with the angle from a remote location, normally the far end of a transmission line. Since the two equipments are effectively time locked together via an internal GPS receiver, external PPS and serial time code the difference in phase angle is used as a measure of system stability. Sequence of events recorder All transitions on the digital inputs of the equipment are recorded and can be displayed independently or with a disturbance or logger record. Input point and time filtering are available to limit the number of events displayed.

5 SPM-ETH: schematic DC Grid Transducer For PV Panels Real Time Events Actuators management WEB User I/O Status report Data Storage SD AC Grid External Transducer I/V ADC 200 ksample/s 8 Channels FPGA Real Time Acquisition up Timing Area Serial Protocol IEC IEEE C NTP/PTP Section - IEEE GPS Receiver OCXO User PC GPS Antenna 10 MHz, PPS, IRIG-B, MOST PERFORMANT TECHNOLOGIES USED: 4 high performance cutting edge FPGA, high performance 8-channel ADC converter, real time processing and event triggering, sub-microsecond system-wide synchronization, high speed gigabit ethernet.

6 SPM-ETH: datasheet 5 Power Quality Harmonics Measurement Standard Per IEC , 100 ms overlapping data window. Measurements: THD, K-factor, rms harmonic current and voltage, rms harmonic current and voltage with K-factor compensation (each harmonic magnitude is multiplied by the square of the harmonic number before summing), individual magnitude and phase. Logged Data Selectable, may be regularly logged or registered; or event-logged when user specified limits are exceeded. Interruptions Logged Data Selectable, may be regularly logged or registered; or event-logged when user-specified limits are exceeded. Flicker Standard Per IEC , P_ST and Instantaneous. Logged data selectable, may be regularly logged or registered; or event-logged when user-specified limits are exceeded. System Control and monitoring System Time, Phase and Frequency System Time Unlimited accumulation with ±1 μs resolution Frequency 7 digits, xx.xxxxx Hz System Phase 0 to 360 with 0.01 resolution Effect of DC None: rejected by narrow-band digital & Harmonics filtering Phasors Standard: IEEE Standard 1344 or C Rate Selectable: 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, 60 measurements/sec for 60 Hz or 1, 2, 5, 10, 25, 50 measurements/sec for 50 Hz. Including frequency and df/dt. Synchronization GPS Section Receiver MHz - 12 channels Tracking, 12 satellites correlation PPS accuracy < 50 ns Antenna connector TNC Acquisition time: 4 minutes Local oscillator OCXO Stability when locked To GPS 1x10-12 (after 24 hours) Ageing in holdover ±1x10-10 day Auxiliary Input references Auxiliary input Frequencies : MHz autodetect via BNC E1 (G.703/9) or T1 via BNC PTP/IEEE-1588v2 via RJ45 connector PTP Section Protocol IEEE (PTPv2) Role Grandmaster Clock Source (with GPS) or slave NTP Section Protocol NTPv4 Role: Master Clock Stratum 1 Optical Section 1x Optical multimode I/O via ST connector Programmable Outputs 12 outputs (via BNC) programmable from the following menu: PPS IRIG B DCLS MHz (G.703/13) 10 MHz Physical Size: 1 Rack Unit Weight: 3 kg net

7 DIGITAL INSTRUMENTS S.R.L. SPM-ETH (Synchro Phasor Meter over ETH) 13, Via Parco degli Scout, 20091, Bresso (MI), Italy.