Power Quality Engineering - Products

G4500 Series Portable Power Quality Analyzer

Power Quality in High Definition
Built on the innovative technology, G4500 series Portable Power Quality Analyzer with its continuous onboard waveform logging is the most advanced power quality meter on the market.

The G4500 series Portable Power Quality Analyzer has the power to determine the root cause of all Power Quality (PQ) issues, so plug it in and never miss another event.

For product details, please click here.

G4000 Series Permanent Mount Power Quality Analyzer

The revolutionary G4000 series Power Quality Analyzer is the next generation in permanent mount power quality analyzers. The G4000 series Power Quality Analyzer provides accurate detection and isolation of power quality problems for effective preventive maintenance.

No Triggers / No Thresholds meaning no missed events. The G4000 series Power Quality Analyzer records all network parameters for up to a year.

For product details, please click here.

The G4000 series Power Quality Analyzer offers a new level of power quality analysis. It continuously records all the information all the time. The main benefit for the customer is the ability to correctly analyze power anomalies (the phrase "power anomalies" incorporates power problems but also any condition which is irregular). In many cases it is not possible to perform corrective action because of two reasons – the source of the problem is not known or in case that there is good estimation the certainty is not high enough to justify action.

The ability to correctly analyze is achieved by 4 domains – continuous logging, logging of all parameters, high sampling and recording rate and multipoint synchronized recording.

Continuous Logging
This is the main feature of The G4000 series Power Quality Analyzer, which is possible using the patented compression technology which allows onboard logging (without threshold triggering) of raw measurement data (waveform). Continuous logging is standard in all of the G4k logger models. Devices that record with no compression.

Logging of all Parameters
The G4000 series Power Quality Analyzer stores continuously all the raw data (voltage and current waveforms without any threshold setting & triggering) and calculates all the parameters in post-processing. In this way, all the parameters are logged all the time. In many cases, recording only a partial set of parameters is a major obstacle in finding the source of a problem. Some examples – measuring RMS voltages on a site with dips where the source was harmonics; measuring only line-to-line voltages on a delta network while the problem was with the line-to-ground.

High Sampling and Recording Rate
The G4000 series Power Quality Analyzer records continuously on all 8 voltage and current channels at the device sampling rate 1024 samples/cycle for G4430. As a result, transient recordings are analyzed with more accuracy and detail in the G4k logger.

Multipoint Synchronized Recording
The G4000 series Power Quality Analyzer, installed in a single location, provides important additional information. In addition to single device installation, unique time synchronization algorithm allows two or more devices to synchronize to each other and to provide complete picture over the entire grid. The maximal time difference between two devices depends on the quality of their network connection and can be less than a single cycle. In this way complete analysis and power flow can be accurately performed.

Note that the time synchronization algorithm is over LAN. A GPS can be used as well, but it is not mandatory. The use of GPS is complicated and adds hardware and labor costs, so LAN synchronization is much more cost effective. G4K Logger can synchronize to GPS with 1 ms accuracy, which allows cycle comparison and/or sample comparison. This means that RMS values can be compared to locating the source of events, such as transients, based on time propagation which is much more accurate.

Browse by Time vs. by Event
Assuming a site had a failure at 9:00 AM. With The G4000 series Power Quality Analyzer you would simply browse to the specific time and see everything which happened. This will allow you to see information that may be ignored in event-based analysis. Moreover, with continuous recording, responsibility can be assigned or cleared with confidence. If it is up to event logging, the confidence level is much lower: the event may have been below the trigger level, on a parameter that was not recorded, or faster than the recorded sampling rate.

Features Matrix Logging
Although logging is one of many features, it is the most important one for power analysis, which is the main objective for installing a power quality analyzer.

Some notable logging capability as follows:

RMS Data – G4430 logger stores over a year of data that includes all parameters and harmonics up to the 511th order; RMS values are calculated every cycle for all parameters and stored
G4430 store current and voltage waveforms continuously on up to 12 voltage, current and temperature channels. The G4430 logs 1.9 billion cycles at 1024 samples per cycle
Transient analysis: G4430 record waveforms on all channels at the maximum rate continuously. The G4430 samples voltages at 1024 samples/cycle.

Ride Through
Internal ultra capacitors (or super capacitors) provide power to the device up to 25 seconds.
Two common examples for the use of this feature is logging of re-closing situation or when more than one device is installed – to understand the sequence of the shutdown.

Important note – there is no use of batteries to provide the ride through feature, which means it is very reliable, no maintenance required and safer to use.

Onboard OPC
G4k has integral OPC server, unlike competitors’ logger which uses additional PC for supporting this important protocol; which competitors’ solution adds complexity and cost to the solution.

The integral OPC server allows seamless connection to any OPC supported application, such as all SCADA systems. This means there is no need to make special protocols – the device can be immediately connected to the SCADA system. We recommend using OPC to all 3rd party applications and not using the old fashioned protocols which requires data tables and programming (such as ModBus or DNP).

Cycle-by-cycle measurements
Many power events have fast behavior, such as motor startup, spot welding and breakers re-closing. In order to correctly analyze such events, calculation of cycle-by-cycle RMS values is critical. To allow accurate analysis it is also very important to have calculation of harmonic every cycle-by-cycle.
IEC 61000-4-30, this standard requires averaging of the measurement every 200 ms (10 cycles at 50 Hz or 12 cycles at 60 Hz). The reason for the averaging is better accuracy and measurement of Inter-harmonics. The problem is the limitation of analyzing fast events.

Our G4K logger is the only measurement device with no need to choose between IEC 61000-4-30 and cycle by cycle measurements. The two methods work in parallel – the device performs FFT (Fast Fourier Transform) every cycle for each one of the two methods and for all the 8 channels (4 voltages, 4 currents).

Fast Flickering
IEC 61000-4-15 defines two periods for monitoring flicker – 10 minutes (P_ST – ST = Short Term) and 2 hours (P_LT – LT = Long Term). In real life, many processes vary during the 10 minute period which makes it difficult to check the flicker level in real time. This problem is known to regulators which tried to provide adequate solution. IEC 61000-4-15 has temporary calculated value called AF5 which is aimed to provide the real time flicker level. This value can show if the flicker level in increasing or decreasing, but cannot show it on the same scale as P_ST/P_LT (P is statistical probability of many samples of AF5's). From this reason the Norwegian regulatory authority (NVE) requires flicker measurement for 1 minute period.

G4K Logger employed extended algorithm to the flicker standard which allows analysis of flicker levels at 2 second resolution. The values are displayed on the same scale as standard P_ST/P_LT which means that if the flicker level is kept constant, the values for 2 seconds, 10 minutes and 2 hours are the same. 10 seconds and 1 minute flicker measurement are provided as well.

Display flexibility
In today's common architecture, the power information is being used in remote locations such as control rooms. From this reason, the use of integrated display is less and less common. Normally, for easy configuration, the customer purchases each device with integral display, but not using it on a day to day basis.

Our G4k logger has unique display architecture. A stand alone display (Model: G4100) can be connected locally to the device, G4K logger, or remotely to more than one device. In this way, it is possible to purchase one display to many devices and to use it either temporary for setup or in permanent installation to all the devices over the LAN.
The display flexibility can also be used when more than one display can be connected to single device. For example, installing one display on the electricity room and another in the electrician office. In this way, each one of the displays can be connected to all the installed devices and each device can be communicating simultaneously from both displays.

Wide range inputs
Fault analysis requires measurement of high voltage and current values, which typically arise during such events. For this reason, G4k logger includes special full scale measurement input channels which are designed to measure wide range of inputs with the same high accuracy (most devices that have transient module have worse accuracy for transient measurements). The full scale and high accuracy allows thorough calculation of events, including transient energy, impedances and transient propagation analysis.
Note that there are 4 values of voltage and current input rating:

Full scale – the maximum values for normal measurement. The device can be continuously connected to this level and measure at his declared accuracy
Fault capture – the maximum value for short time that the device can measure, normally not at maximum declared accuracy.
Continuous Overload – the maximum values that the device can continuously withstand without damage (the measurements are not correct under these conditions)
Short term Overload – the maximum short time conditions that the device can withstand without damage (the measurements are not correct under these conditions)

The table below compares the inputs rating of G4k:

Periodic Energy logging
Utility companies use two systems of pricing approaches:

Flat price, in which the cost of kW is the same any time, based on the average cost of kW generation.
Time-of-Use (TOU), in which the cost of kW varies during the day and the year, depending on the actual cost of kW generation and transmission.

Most utility companies adapt the TOU method, since it is more rational both to the customer and to themselves. This method prevents over charging and subsidizing.

Most digital power meters include energy metering, in one of the three methods:

Accumulated kWh value – one register counts the kWh and can be reset by the user (usually protected by a password).
Multiple Registers – the TOU scheme is configured in the power meters, and each tariff code increase one register. In this way, the energy cost is calculated by multiplying each register by its fee.
Periodic logging – the power meter stores the kWh and kVArh information each pre-defined period (typically 15 or 30-minute). The energy cost calculation is done by post processing the stored data.

The first method is very limited and supports only flat pricing and it is in use only by low-cost meters.

The major drawbacks of the second method are:

Computation is done only from the time of the last reset and cannot be performed on sub-periods.
The configuration must be in advance – if there is wrong time setting, a change or wrong setting in the scheme, it is not possible to overcome the change.
It is not possible to monitor the actual consumption each period and to use this information to adjust the use of energy and reduce cost.
Since the TOU scheme is stored in the power meter itself and not computer software, there may be substantial limitation on the number of registers, seasons, special days (i.e., holidays) etc. Even if the meter supports the current TOU scheme, it may not support future ones.

The third method is the most modern concept which allows full flexibility of TOU – comparing TOU schemes on same data, sub-period calculations and support future TOU schemes.

G4k logger uses the third method while competitor like ION uses the second method.

Detailed Inter- and Sub-harmonics
Inter-harmonics are frequencies which are not integer multiplication of the fundamental frequency (e.g., 300 Hz is harmonic while 310 Hz is Inter-harmonic) while Sub-harmonics are frequencies below the fundamental.

Inter-harmonics are used mainly for analyzing external interferences to the network (e.g., from power line communication) and to perform predictive maintenance (together with Sub-harmonics).

For example, when motor's components start to wear, the motor generates Inter and/or Sub-harmonics (depends on the problem type). G4K Logger measure both inter-harmonics and sub-harmonics.

Inter-harmonics are part of EN 50160 as well as other standards. However, the standard refers to their total. In order to analyze the data, not only estimate it, similar to the difference between THD and individual harmonics display.

G4k logger displays the Sub- and Inter-harmonic value for each 5 Hz from DC to 1275 Hz (256 values).

Two Fast Ethernet ports
In today's market, the Ethernet is becoming more dominant than ever, also in electrical installations. Since that, G4k logger major communication channels are based on this commonly used infrastructure. It provides three unique advantages – the port/s are integral with no extra cost, fast communication (10/100 M) and the availability of two independent ports (G4420 and G4430).

The amount of data transportation emerged the need for faster Ethernet communication and nowadays most or even all of the Ethernet installations supports fast 100 MB communication. G4k logger works seamlessly both on 10 MB and 100 MB network providing efficient data transfer.

The two Ethernet ports provide connectivity to two different networks (it is NOT the same as connecting a hub to the device, which is few ports on the same network). There different usages for the two ports. Some examples: one port for LAN communication and another port for local display; one port for LAN communication and one port for downloading data using laptop; or connection for two completely separated networks such as in wind turbines where port is connected to the wind turbine manufacturer's network and the other port to the utility network.

PoE
PoE stands for Power over Ethernet. This revolutionary standard (IEEE 802.3af) defines the delivery of 48VDC over the Ethernet cable as the cable continues to communicate data. There is no problem to connect non-powered ports to powered ones since the protocol has negotiating process.

It is possible to take advantage of this technology in many situations. The two most common are:

Connection of the display with only single standard cable
Connect UPS power to the communication switch which supports PoE, thus place only communication cables to the devices for providing UPS backup to different G4k devices

Comprehensive Webserver
Most meters that uses Ethernet communication offers some type of web server – access to the meter using standard Internet browser such as Internet Explorer. However, G4k series logger was designed to use the Ethernet as the main communication channel and the web server to be its main control and monitoring interface. Since that, the web server on the devices is very comprehensive and includes all device functionality, including measurement monitoring, programming and events monitoring. The web server includes graphic component to display harmonic graphs, waveforms and phasors including zooming capabilities.

Modularity
G4400 logger is built by separated modules. The standard configuration includes power supply module, DSP module and CPU module. This configuration allows adding of different additional modules, as well as upgrading part of the three standard modules. Moreover, it is possible to connect more than one module of the same type. For example, the Multi I/O module includes 8 digital inputs. It is possible to use 2 modules to have 16 inputs or 3 modules to have 24 inputs. The maximum number of modules that can be connected is 9.

External Communication Concept
For communication expansion G4k logger uses external modularity concept. Despite the incomparable flexibility of the modular design, support for different communication types is done using external modules connected over LAN. The reason for this is the ability to rapidly adapt the emerging communication technologies. Since that, any communication router with Ethernet port can be used. Currently G4k logger supports GPRS, Edge, UMTS, ISDN modem, Dialup modem, WiFi and ADSL. In addition, it allows simultaneous connection of few communication channels, including from the same type.

GPRS Dynamic IP Addresses
In locations where physical connection to devices is not possible, cellular communication is used. However, not all cellular solutions are the same from the customer point of view. Similar to Internet providers, cellular operators can provide either dynamic or static IP addresses. While there is no problem with dynamic IP when the device initiates communication to the server, if there is a need to query the device (e.g., change the device configuration) it requires special solution. The solution is even more complicated than with Internet IP addresses, since the dynamic IP is in the cellular network and not the Internet.

Some power quality analyzers' manufacturers use fixed IP when polling the devices is required. The problem is that the cellular providers charge extra cost for each static IP address, which means the operational costs for the system is increased. Moreover, many cellular providers do not provide static IPs at all. In addition, many fixed IP solutions require GPRS modem on the server side as well. Since GPRS prices depends on traffic, both outgoing and incoming, this doubles the GPRS data transfer charges.

G4k uses VPN channel from the device to the server. In this way, a secured channel is created from the device with dynamic IP to the server, which allows the server to poll the device, regardless of its IP address. Moreover, the server itself can be connected to the Internet, which reduces the GPRS data transfer charges. There is no special requirements from the SIM card in the GPRS modem/router – any GPRS enabled SIM card can be used and the total operation costs are much less than other solutions and the system is much simpler, which makes it easier to implement and to be operated.

Compact Flash (CF) and USB Expansion
In addition to the modular design and the external communication concept, it is possible to provide expansions by using standard compact flash (CF) cards and USB modules (the USB is similar to computer side USB, which means can accept USB dongles). In this way, expansion options are very wide and cost-effective.

Currently, the only supported card is GPS CF. Example for future options (depends on market demand): Disk on Key to locally download data, WiFi, Bluetooth and IrDA.

Data Analysis & Reporting Software

G4100 Display Unit

G4100 Remote Display LCD Unit is an integral part of the Power Quality Data Center system, allowing interconnectivity with the G4400 series instruments for configuring and monitoring the electrical distribution system.

G4100 Remote Display Unit (RDU) connects and communicates with the G4000 series Power Quality Analyzer directly via RJ45 network cable or through IP communication from anywhere in the world. One RDU can be used to monitor and configure many G4400 series instruments.

Contact our application engineers for further details click here.