Ripple control technology
The ripple control (engl. Ripple control ) is a remote control via the existing power supply network . The control signals are only transmitted via the power supply from central ripple control transmitters to decentralized ripple control receivers.
Electricity consumers usually receive information from the energy supply company (EVU), for example about switching to low-tariff electricity . Furthermore, the data is used for feed- in management in the course of the legal obligation of the decentralized electricity producers to participate in network management.
Ripple control can be seen as a simple form of PLC (Power Line Communication, see carrier frequency system ), via which unidirectional data with a very low data rate is sent as broadcast . Ripple control technology is a contribution to the development of an intelligent power network (smart grid).
principle
The control commands are transmitted by pulse trains in the frequency range from 110 Hz to approx. 2000 Hz, which are superimposed on the mains voltage with an amplitude of approx. 1 to 4% of the respective nominal voltage (up to 9% are permissible, depending on the frequency). The RU's own ripple control frequency is switched on and off for transmission according to a specific code (pulse pattern), which creates a pulse telegram. Depending on the code used, these pulse rasters are structured differently and their shortest running times are 6.6 s ( Decabit from Zellweger) and their longest running times are in the range of minutes .
In principle, all central points in the EVU's network from the low-voltage to the high-voltage level are suitable for feeding in the pulse telegram. Such a feed is implemented with a transmission system, which consists of a transmitter and a coupling device. The output of a ripple control transmitter for medium voltage coupling is 80 to 200 kVA, for high voltage coupling it is up to 2400 kVA.
Standards and VDE recommendations specify the criteria according to which a ripple control transmission system is to be dimensioned or operated and how high the maximum amplitude of the ripple control frequency to be superimposed may be. For example, the "EN 50 160" standard defines the limit values and tolerances for the voltage quality in public electricity supply networks. The VDEW frequency advisor suggests which ripple control frequency is used by a German power supply company. Alternatively, there is also radio ripple control technology .
The following systems are used:
- Ricontic
- Landis + Gyr
- Semagyr50
- SemagyrTOP
- RWE
- Sauter
- Pulsadis
- TELENERG
- Versacom
- ZPA
- ZAG 60
- ZAG 180
- Decabit
- Swistra
receiver
The consumer to be remotely controlled is preceded by a special receiver (ripple control receiver) which filters out the pulse telegrams from the network and derives the required control information from them. The ripple control receiver can also be integrated in a meter or mounted in a "piggyback" design on the terminal cover of a meter.
application
The grid-bound ripple control technology is mainly used in load control and load regulation, but also in the feed-in control of photovoltaic and wind power plants due to the EEG 2012 .
Load control
The classic application in load control is switching from special multi-tariff electricity meters to so-called low-tariff electricity and at the same time switching on high-performance consumers at the customer's premises, primarily hot water storage tanks and night storage heating. The purpose is to utilize the excess capacities of the power plants whose output can only be regulated slowly in the so-called low - load phases .
Industrial tariffs and public lighting systems (sometimes separated into "night" and "half-night switching") are sometimes switched over. The original purpose of this nighttime electricity tariff changeover ( using tariff switching devices ) has been given a new meaning by the liberalization of the electricity market.
Furthermore, disturbance-related changes in power generation and distribution with ripple control technology can be absorbed by interventions on the consumer side - within certain limits. So z. B. a selective load shedding of less important network load in the event of a lack of power prevent the shutdown of vital consumers.
Special ripple control receivers coupled with a contactor make it possible to remotely disconnect the customer system in question from the network for collection purposes if payments are not made.
Load regulation
In a distribution network, the generation and consumption of electrical energy must match at all times. The transmission facilities must also never be overloaded. Usually the consumer determines when and how much energy he takes from the distribution network. This means that generation in the power plants has to be continuously adjusted. With the help of ripple control, it is possible to influence consumption by switching loads on or off. Storage heaters, water heaters and heat pumps are suitable as loads, because they can do without energy for a limited time.
For this purpose, a control system is used in the ripple control system that continuously compares the energy consumed with a setpoint and, if necessary, switches loads on or off. The regulation must take into account that all loads are equally affected by disconnections.
The generation and distribution systems must be built for the maximum possible output (peak load). Load peaks can be reduced through load control. This means that generation and distribution systems can be better utilized. Additional consumers can be connected to existing systems without the need for investments to increase the possible peak load.
Step control of feeders
The latest version of the EEG 2012 stipulates that all photovoltaic systems with an installed capacity of more than 30 kW must be equipped with technical equipment with which the network operator can remotely reduce the feed-in power at any time in the event of network overload. Both radio ripple control technology and audio frequency ripple control technology offer network operators the option of gradually controlling EEG systems (e.g. 100%, 60%, 30% and 0%) and avoiding possible network overload in advance.
Alerting
Before the introduction of wireless signaling devices (radio signal receivers, cellular radio, etc.), portable ripple control receivers were occasionally used to alert emergency services and fire departments. After sending a special ripple control telegram, these devices gave an optical and acoustic alarm. The person to be alarmed always had to be in the network area of the utility company at a location where mains voltage was available and had to connect his ripple control receiver to the mains.
Example:
From 1962 to 1979, ripple control technology was used as an alarm system at the Landau fire brigade in the Palatinate . For this purpose, the alarm signals were fed centrally into the power grid in the form of various pulse combinations. Appropriately constructed receivers, consisting of various relays that were matched to the control frequency, could then be connected to any point in the power grid. As soon as the combination of impulses set on the receiver was sent through the mains, a control output was activated in the receiver and an alarm signal was triggered. Since this alarm system was fixed to a specific location and the firefighters could only be reached where the receiver was connected to the power supply, the alarm system using ripple control technology was replaced in 1979 by an alarm system made up of radio receivers and sirens , which is triggered by radio and is still in operation today.
Analysis options
The signals from audio frequency ripple control systems (TRA) can be received and analyzed in the power network with the help of appropriate measuring devices. A few companies - mainly manufacturers who also offer ripple control systems - supply devices and systems for this.
Ripple control signals DX
The analysis of ripple control signals with the help of PC - sound card possible. To do this, an FFT analysis program must be installed on the PC and the sound card input must be connected via a capacitor to the secondary winding of a safety transformer whose output voltage should not exceed 3 volts. In this way, ripple control signals from far distant utility companies can also be received.
literature
- Ernst-Robert Paessler: Ripple control technology . Publicis Corporate Publishing, 1994, ISBN 3-89578-004-9 .
- Adolf J. Schwab: Electrical energy systems: generation, transport, transmission and distribution of electrical energy . 1st edition. Springer, Berlin 2006, ISBN 978-3-540-29664-5 .
- A. Dennhardt: Basics of audio frequency ripple control technology and its application . Verlags- und Wirtschaftsgesellschaft der Elektrizitätswerke mbH (VWEW), 1971, ISBN 978-3-8022-3001-1 .
See also
Web links
- Ripple control technology ( Memento from August 20, 2016 in the Internet Archive ), frequency table Germany
- Ripple control technology ( Memento from August 20, 2016 in the Internet Archive ), frequency tables Switzerland and Lichtenstein
- Instructions for receiving ripple control signals with the PC
- Toonfrequent in Nederland (Dutch)
Individual evidence
- ↑ Ripple control ( memento of the original from August 3, 2009 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. , Systems and frequencies
- ↑ a b EEG2012 , law for the priority of renewable energies
- ↑ Landau fire brigade - alerting, section '1962 ripple control system' accessed January 28, 2014
- ↑ Heinz Arnold: How the load control works using ripple control technology. Retrieved August 30, 2019 .
