KoCoS Blog

Gas has been getting more and more expensive for a year now, and the price of electricity in Europe is also rising significantly. Are these prices related and what role does which power plant play in this?

Gas shortage. Why is the price of electricity rising at all?
Since in Germany, as in the rest of the world, electricity is mainly generated by fossil fuels, the price of a kilowatt-hour naturally depends on the basic price of gas, coal, oil and, to a certain extent, uranium. If the prices of fossil energy sources rise, the price of electricity also rises.

How have energy prices developed so far?
Concerns about a shortage of gas supplies from Russia have driven gas prices ever higher, and not only in Germany. Power plants paid almost 227.0 percent more for natural gas in June 2022 than in the previous year. The gas bills of many end consumers have tripled. Alongside these rapid increases in prices in the gas market, electricity prices have also risen at the same time. Within one year, for example, the price of electricity on the Leipzig European Power Exchange (EEX) has increased 10-fold (as of August 2022) - from 50 to 565 euros per MWh. Of course, this also has a knock-on effect on consumers: the electricity price for new contracts in mid-November 2022, for a consumption of 4,000 kWh incl. basic fee, was 0.427 euros per kWh - and the trend is uncertain.

And what about electricity from renewable energies?
Electricity from renewable energies is by far the cheapest way to generate electricity. Once wind or solar power plants are built, they consume almost no resources for direct electricity production. However, they do not supply electricity continuously. This means that although energy from these sources is cheap, it is not constantly available everywhere without large storage facilities and well-developed electricity grids. Does the price of electricity fall when more electricity is fed into the grid from renewable sources? No, unfortunately it is not that simple. This is because the electricity market works according to the "merit order" principle.

Definition: Merit order
The merit order is the order in which power plants are deployed, which is determined by the variable electricity production costs. The cheapest power plants are switched on first to meet demand, and the last power plant with the highest marginal costs needed to meet demand determines the price. The merit order thus determines the electricity price on the energy markets.

In a simplified way, this means: All power plants offer their production capacities until enough electricity is produced in Europe to cover demand. However, no distinction is made in the type of generation: All suppliers receive the same price, determined by the most expensive power plant on the grid. In the merit order principle, for example, it does not matter at all how cheaply the renewable electricity was generated. Subsidies for the expansion of renewable energies do not count either.
Thus, at present, a single gas-fired power plant on the grid is enough to greatly increase the price of a kilowatt hour of electricity, regardless of the low costs of other energy sources or "power plants" at that time.

So why is there a "merit order"?
In a conventional market, supply and demand would determine the price - until the time when a product is no longer available. As a result, however, gas-fired power plants would then almost never be in operation, as cost-covering operation is not guaranteed. The "merit order" balances this out so that there is always enough electricity available to meet demand and the grids remain stable.
Each producer offers its electricity in such a way that its costs (marginal costs) are covered. All offers are then successively made until demand is covered - the most expensive power plant used then determines the price for everyone. This power plant only covers its marginal costs, all others make profits. The resulting price is called the marginal price.
Marginal costs are the costs incurred to produce the next commodity or, in this case, the next megawatt hour. Investment or capital costs are not included, but fuel costs, for example, are.
On the energy market, it generally applies that the "product" electricity must not be "sold out", as otherwise the energy supply can be disrupted and, in the worst case, a local or area-wide blackout could occur.

Who invented the merit order principle?
"The marginal price (found through the merit order) is not an artificial rule that someone made up," Lion Hirth elaborates in the Stuttgarter Zeitung. Lion Hirth is junior professor for energy policy at the private Hertie School in Berlin and managing director of the energy consulting company Neon. "It is not an arbitrary choice between alternative market designs, but the natural way prices form in free markets," he continues. Other commodity markets also function according to this principle - "no matter whether it is oil, gas, copper, milk or solar plants", says the energy expert.

What is happening at the moment?
Currently, several developments are coming together: Firstly, about half of the 56 nuclear power plants in France are currently out of operation due to maintenance work or technical defects. Secondly, the low water level of the rivers is hampering the supply of coal to the coal-fired power plants. And thirdly, the gas price is at a high level and, as described above, influences the electricity production costs.

Will coal, nuclear power and renewable energies not suffice?
Unfortunately not. On the one hand, this is because the current capacities of hydropower, wind power and photovoltaics are not sufficient to cover the entire electricity demand, neither in Germany nor in Europe as a whole. In addition, as described above, many conventional power plants are currently shut down or can only be operated to a limited extent.
Furthermore, there is a lack of transmission grid capacities across Europe. Often, for example, the electricity generated on the windy North Sea coast in Germany cannot be transported to the energy-hungry south of Germany. The Federal Network Agency reacts to such a bottleneck with a "Redispatch": the output of wind turbines is reduced in the north and the output demand of the power plants is increased in the south so that an overload of the electricity grid is avoided. Gas-fired power plants, which can adapt their electricity production particularly flexibly and quickly, are often used here. Of course, this also has additional effects on the electricity price.

Opportunities for action and risks
The increased gas price, mainly caused by the war in Ukraine, is also driving up electricity prices. Since electricity is included in the prices of many other products, including breakfast rolls, this is fuelling inflation. For weeks, there have been many discussions on how the price increase could be stopped.
"A discussion about redistributing profits and relieving the burden on consumers, but maintaining savings incentives, i.e. not a simple price cap, is in my opinion the way to go in the short term," says Christoph Maurer, Managing Director of the Aachen-based energy consulting firm Consentec. However, a fundamental change in the market design should definitely not be decided in the short term, he warns. "The risk of then arriving at solutions that have not been thought through and possibly even intensifying the crisis is very high" Maurer, an energy expert, told the Stuttgarter Zeitung.

References: The magazines: "Zeit, Standard and Stuttgarter Zeitung", the technical magazine "Chip", Wikipedia and own research.

Six-Sigma in silicon carbide substrate manufacturing with LOTOS 3D
measurement systems.

Achieving the stringent zero defect strategy in the automotive industry is becoming a major challenge for silicon carbide substrate manufacturers. Both the switch from 150 to 200 mm wafers and the general shift in their focus away from pure silicon are making manufacturers struggling to achieve sufficient yields and reliability.

SiC is a combination of silicon and harder carbide materials, and its wide bandgap has made it a key technology for battery-powered electric vehicles. Silicon carbide operates at higher power, higher temperatures and higher switching frequencies than silicon. These properties can be used to increase the range of electric vehicle batteries and reduce charging time.
"People want to charge their cars in less than 10 to 15 minutes, and that's going to continue to evolve," said Sam Geha, CEO of Infineon Technologies' Memory Solutions. "That requires silicon carbide and other technologies, as well as more automation."

LOTOS 3D measurement systems help implementing the zero-defect strategy toward high-yield production processes without any scrap. Shortly after crystal growing, silicon carbide boules can be inspected for geometric sizes, eliminating scrap in subsequent production processes.

LOTOS checks all common parameters such as outer diameter and diameter at the primary and secondary flat, the flat lengths, the notch contour, as well as their exact angular positions.

Power Quality

The European standard EN 50160 describes the main characteristics of the supply voltage at the customer's point of connection in public power supply networks. It specifies the limits that must be respected by the various parameters of the mains voltage under normal operating conditions.
Essentially, the following parameters must be permanently monitored:

  1. Voltage amplitude
  2. Frequency
  3. Symmetry
  4. Flicker
  5. Harmonics

For example, EN50160 allows a tolerance of +-10% of the nominal voltage for voltage deviations, which must be met by 99% of all measured values within a weekly interval. For the remaining 1% within a week, a deviation of +10 and -15% is allowed.
10-minute average values are used to determine the voltage deviation. The specified deviations therefore apply to slow voltage changes.
For the other parameters such as frequency, total harmonic content, individual harmonics, ripple, flicker, etc., the same procedure is followed. However, with different limit values, percentiles, averaging and sometimes other observation intervals.

Power System Disturbances
As a result of mains disturbances, rapid voltage changes usually occur, the measured values of which are determined 2 times per mains period (rms1/2). If the measured value falls within a range of 1% to less than 90% of the nominal voltage, this is called voltage dip. If the measured value of all phases falls below the 1% threshold, there is a supply interruption. Measured values greater than 110% of the nominal voltage are referred to as an overvoltage.
Power disturbances are classified according to their duration and the amplitude reached.

Power Quality Report
Since these power quality thresholds are valid only for the undisturbed operating case, measured values accumulated during a power disturbance must be marked and excluded from the statistical power quality assessment.
The Expert operating software for the EPPE and SHERLOG devices can perform this work automatically on request. It generates fully automated, standard-compliant power quality reports from all measuring points over definable observation periods.
The content of the reports can be customized and, in addition to the standard-compliant power quality verification, also includes information on the number and duration of supply interruptions, voltage dips and swells, including classification according to UNIPEDE, CBEMA, ITIC and SEMI F47.
Also signal fluctuations and statistics on current, active, image and apparent powers, as well as power factor can be included in the report.
The reports can be automatically saved as PDF or DOCX files for later use and sent to network printers and e-mail addresses.

By:
Brian Burke, Application Engineer, KoCoS America LLC
Guy Wasfy, Managing Director, KoCoS America LLC
Jürgen Dreier, Product Manager, KoCoS Messtechnik AG

Bonding connections and ground connections are an essential component for the safe functioning of power and communications engineering systems and for ensuring personal and equipment safety.
Unwanted voltage potential differences are to be avoided by means of ground connections and grounding procedures. These voltage potential differences can occur between metallic components and ground, which can endanger human safety and/or technical equipment.
Metallic components must be connected to ground potential to prevent dangerous voltages. Voltage drops are reduced by grounding all non-voltage-carrying parts and by extensive ground potential equalization (grounding system). It is important to make sure these grounding connections have a low resistance. Resistance measurements must be made at both potential and ground connections to ensure that a sufficiently good low resistance connection is achieved and maintained.

Below is an example of application in power distribution where grounding and equipotential bonding and their good connection are important.  However, there are many other applications where grounding and equipotential bonding must be taken into account (Rail vehicles, aviation industry and aircraft maintenance, etc.). Typical applications for equipotential bonding and grounding are found in power distribution substations in low and medium voltage networks and especially in high voltage substations. The grounding of all non-voltage-carrying parts and extensive ground potential equalization reduce voltage drops that can occur due to capacitive or even inductive voltage coupling.

An example of these non-voltage-carrying parts is the mechanical disconnect switches used to remove a switchgear from service. Due to the need for human interaction with these physical switches, it is critical their grounding connection is not compromised. These straps are metallic braids secured via bolts to the switch and ground connection point. These straps can become poor conductors due to corrosion or physical damage. A compromised strap could lead to improper grounding of the switch causing a hazardous touch potential when the switch is to be used. To ensure the straps are functioning accordingly, the connection across them can be tested with a micro-ohm measurement. A failing strap will have a high resistance reading where as a properly conducting strap will have a low resistance reading. High resistance of the connection or, in the worst case, a failing strap could require the bolted connection points being cleaned and reconnected or the strap being replaced entirely.

Aside from bolted ground straps, the grounding connections can be bonded through exothermic welds. These welds result in superior mechanical and electrical bonding. Especially for conjoining dissimilar metals, such as joining a copper grounding rod to a galvanized metallic structure in a substation. These welds, when done properly, create a solid and reliable connection (Figure 2) Due to improper heating or unwanted moisture, the welds can have pitting or gaps (Figure 3) and be considered poor quality both mechanically and electrically. Performing a micro-ohm resistance measurement across these connections can give insight into the weld quality. The more solid the weld connection is, the lower the resistance reading will be. A poor quality weld could result in a less reliable grounding connection.

The resistance measuring instruments from KoCoS Messtechnik AG are ideal for measuring equipotential bonding and earth connections. The PROMET SE precision resistance measuring instrument is used to determine low-resistance in the μΩ and mΩ range. With adjustable test currents of up to 200 A, in conjunction with a four-wire measurement method, the systems provide measurement results for the highest accuracy requirements. The use of state-of-the-art power electronics and the robust design guarantee maximum reliability for mobile use.

The PROMET SE is ideal because it is battery operated and does not require a mains connection. Some of the connections described may be at height so that the tester is standing on a ladder or similar. Without the battery operation, the meter would also require a portable generator. Finally, the PROMET SE is very lightweight and easy to transport.  It weighs less than 5 pounds and can be conveniently transported on-site to test the many ground connections.

If you have questions or additions to the resistance measurement or to our measuring devices? Then contact us via the comment function here on the blog or by mail to info(at)kocos.com.

Ensuring the highest product quality is a priority and indispensable goal, especially in the production of food. The tightness of the product container plays an important role.

Leaks can cause their contents to escape to the outside. It is much more important, however, that germs penetrate the container and spoil the products as a result.

The INDEC vacuum testing systems automatically monitor the tightness of containers directly in the production process. A wide variety of containers such as bottles, jars and cans are checked for leaks without contact and defective containers are removed from the product flow.

Sometimes, however, small food manufacturers have limited financial budgets to invest in a new complete system for checking closures. For this reason we have developed the price-sensitive basic system INDEC VD 80 and launched it on the market now. The INDEC VD 80 only contains the three core components display unit, connection unit and the sensor head. The required frame components for holding and aligning the sensor head and for holding the display unit and the connection unit often exist from old sensors systems that have been used up to now, which can no longer be repaired economically after more than 15 years of usage. With little effort, those can be modified to accommodate the new core components. The INDEC VD 80 does not differ in any way from the INDEC VD 100 in terms of functionality and reliability.

INDEC VD 80 consisting of display unit, connection unit and sensor head
Of course, if required, these additional components can be retrofitted at any time at a later date according to the following table.

Due to the excellent, semi-automatic self-learning process for determining the sensor parameters (recipes), it is possible for the customer to start up the system himself in the same way as for the INDEC VD 100 with the INDEC VD 80. The deployment of a KoCoS technician or a technician from our local representative on site is not mandatory.

When transformers are switched on, inrush currents can occur that exceed a multiple of the transformer rated current. Since the inrush current decay again after a few milliseconds, protection devices must separate these from fault currents and block tripping accordingly to ensure correct operation.

If the inrush current is analyzed with a suitable measuring device such as the SHERLOG fault recorder, an increased 2nd harmonic component can be detected. This increased proportion is also used by the protection devices to provide inrush stabilization. If the proportion of the 2nd harmonics exceeds a specified percentage, the trip is blocked by the protection device. 

Since this is a blocking of protection functions, the inrush stabilization testing has to be part of the protection testing. For this purpose, test quantities that are within the tripping range of the protection device have to be superimposed with corresponding proportions of harmonics and the reaction of the relay has to be evaluated. With the VD-Monitor of the ARTES 5 testing software, such test sequences can be created in a simple manner. The ratio between the fundamental signal and the superimposition can be kept constant or changed in steps by means of ramp definition. Thus, combining several test sequences with different settings enables phase-selective testing of the inrush stabilization in a single test routine.

 

Any questions or additions to the topic? Then please use the comment function here in the blog or send an email to bfleuth(at)kocos.com.

When distributing electrical energy, it must be remembered that poor current connections cause losses that must be compensated for by additional power from the power generator.

The power loss at the contact point depends on the current and the resistance: P = I²·R

When transmitting high currents, the aim must therefore be to achieve the lowest possible contact resistance at the connection points. The contact resistance is influenced by several variables and increases in the course of the operating time due to aging. By testing at the installation site, a faulty connection can be detected and eliminated.

The quantity for assessing an electrical connection is the resistance. The resistance of an electrical connection is in the micro ohm range. These small resistance values require special measurement technology, such as resistance measurement in four-wire technique (Kelvin method).

In order to assess the quality of a connection, the PROMET SE and PROMET R300/R600 resistance measuring instrument is able to determine the quality of a connection. Due to two voltage measurement inputs, a simple and quick determination of the quality, e.g. of screw connections on bus bars, is possible. The determination is made via the quality factor. This is defined by the ratio of the resistance of the connection over the overlap length to the resistance of the bus bar of the same length.

The quality factor K is the ratio of the resistance RCON of the connection over the overlap length lCON to the resistance RREF of the bus bar of the same length lREF.

     K = RCON/RREF

     RCON: Resistance of the connection
     RREF: Resistance of the bus bar

Therefore, when making an electrical connection, care must be taken to limit aging and provide a low-maintenance and reliable connection.

By determining the resistance or quality of a connection, the correct connection can be verified during installation and maintenance and a reduction in electrical losses, an extension of service life and an increase in plant safety can be achieved.

Do you have questions or additions to the resistance measurement or to our measuring devices? Then contact us via the comment function here on the blog or by mail to info(at)kocos.com.

Spanish user interface at INDEC VD 100 vacuum inspection device

The vacuum inspection systems from KoCoS, which have been tried and tested in practice all over the world, monitor a wide variety of containers such as bottles, jars and cans for leaks in-line during the production process. Containers with insufficient vacuum are reliably detected and removed fully automatically. Highest reliability and easiest handling characterize the processor controlled inspection systems and are the first choice for many food manufacturers.

INDEC VD 100 vacuum testing systems are also increasingly used in Spain for cap inspection. In response to numerous requests by customers at this region, KoCoS decided to develop a Spanish user interface for INDEC VD 100 system and to integrate it as standard in the new firmware. This new Spanish user interface is now available for all new orders for INDEC VD 80 / VD 100 series since spring 2022. Of course, this software update can also be retrofitted in already delivered INDEC VD 100 units.

Users of the INDEC VD 100 can now simply choose their preferred language version between the four user interfaces in German, English, French and Spanish. This significantly simplifies the operation of this INDEC series. Even untrained personnel are now able to generate the relevant sensor parameters (recipes) on the INDEC VD 100. This measure also improves the safety of operation and the acceptance of the INDEC VD 100 series.

The complete commissioning and installation of INDEC VD 100 on the customer's own initiative without the support of a KoCoS technician on site in the Spanish-speaking region is facilitated. This innovation enables the end customer to save considerable installation costs.

KoCoS offers project planning and cabinet production for complete SHERLOG solutions

KoCoS is well known as a reliable manufacturer of high-quality test and measurement systems. However, only a few people know that KoCoS also designs and builds complete control cabinets according customer specifications and supplies them worldwide.

The installation concept of measurement data acquisition for network status and fault detection of electrical power supply networks and systems can be roughly divided into centralized and decentralized installations. Which concept is used is essentially decided by the individual conditions on site. It is therefore not surprising that a mix of both methods is often used.

 

Decentralized solution

In the case of the decentralized solution, compact measuring devices with a few analog and digital inputs are usually integrated into existing switchgear or protective cabinets and are used to monitor one or two bays. One advantage of this method is, for example, the low installation effort due to short cable runs, which also allow the measuring systems to be integrated directly into existing protection or measuring transformer circuits.

 

Centralized solution

In the case of the central acquisition solution, on the other hand, extensive measuring systems are required that have to record larger plant areas, entire voltage levels or even the entire plant. Several hundred measurement inputs are sometimes required for this application. Such measuring systems are then installed in dedicated cabinets in which all the necessary measuring points are brought together.

For such central systems, KoCoS supplies not only the measuring equipment but also, complete solutions in fully wired and tested cabinets.

To this end, KoCoS works out the target concept together with the customer and takes on all tasks from engineering to detailed planning, drawing production, cabinet manufacture, system parameterization and documentation.

Only high-quality components from well-known manufacturers are used in the construction of the cabinets and installed on site at KoCoS.

After commissioning and individual configuration, on-site or remote maintenance and service are also part of the range of services.

 

 

 

 

 

 

 

Any questions or additions on this subject? Then please use the comment function here on the blog or send an e-mail to mjesinghausen(at)kocos.com.

Modeling and generating power quality disturbances

Monitoring power quality (PQ) in the distribution system is an important task for energy suppliers and their customers. In a distribution system, various types of faults cause power quality disturbances. Power supply operation can be improved and maintained by systematically analyzing power quality disturbances.
The power supply is designed to operate with a sinusoidal voltage at a constant frequency. Power quality disturbances occur when the magnitude of the voltage, frequency, and/or waveform deviation change significantly due to various types of faults such as nonlinear loads, switching of loads, weather conditions, etc.
The effects of poor power quality depend on the duration, magnitude, and sensitivity of the connected equipment. Poor power quality can lead to process interruptions, loss of data, malfunction of computer-controlled equipment and overheating of electrical equipment.
It is important to detect and classify power quality disturbances. A variety of waveforms can be generated by simulations and be useful for disturbance detection and classification.
The waveforms of the possible disturbances are created in this description by mathematical models. The EPOS 360 three-phase signal generator and EPOS operating software are available for modeling and generating signals to analyze the events in the power system.

The mathematical models of the power quality signals can be implemented in the EPOS operating software by means of the "Signal Editor" module and generated with the EPOS 360 signal generator. The use of equations offers advantages as it is possible to vary signal parameters in a wide range and in a controlled way.
The following pictures show the different power quality signals which have been defined via the Signal Generator module.

Ideal voltage/current source
An ideal AC voltage source generates a continuous, smooth sinusoidal voltage.

Voltage fluctuations
A drop (undervoltage, voltage dips) or rise (overvoltage, swell) of the mains voltage of at least ½ cycle up to several seconds.

Voltage interruptions
A significant or complete voltage interruption. The interruption can be short-term but also permanent.
 

Harmonics
Distortion of voltage and current waveforms caused, for example, by operation of nonlinear loads.

Transients
A sudden disturbance in the line voltage that typically lasts less than one period and consequently the waveform becomes discontinuous.

In this description, the basis for generating typical power quality disturbances was presented. This signal generation solution includes the EPOS 360 signal generator supported by a PC with the EPOS operating software. The software includes the Signal Editor module, through which parameters such as amplitude, phase angle and frequency can be adjusted for signal generation. Furthermore, the Signal Editor module provides many other functions for adjusting the basic parameters, such as offsets, overlays and harmonics.
The hardware and software functionality makes it very easy to perform the generation of diverse waveforms. The generation of the previously defined waveforms is provided by four voltage and three current output channels of the EPOS 360. The signal generator can thus be used in procedures for testing instruments and devices for power quality measurement and analysis.

For more information, please refer to the following application notes:

  1. Signal generator EPOS 360 - A laboratory for power quality
  2. Three-phase signal generator for precise power network simulations

Do you have any questions about our measuring devices?
Then contact us via the comment function here on the blog or by mail to info(at)kocos.com.