DE102014116846A1 - Electromagnetic mains voltage regulation and Smart Grid application - Google Patents

Abstract

The present invention describes a device (10) and a method for providing a regulated line voltage (UR) in particular in 400V local networks with overvoltages of up to 20%. The device (10) uses an electromagnetic control coil (23) on a control magnetic core (43) and thus controls the complex voltage drop of power coils (11, 12) through which the alternating current to be controlled flows, the magnetic circuit of the power coils (11, 12 ) flows through the control magnetic core (43) and the bias of the control magnetic core (43) is varied in the sense of regulation. Thus, in a surprisingly simple and reliable manner, a safe mains voltage control on an electromagnetic basis without sensitive and expensive electronic power semiconductors. The mains voltage control is used in particular to compensate for mains voltage fluctuations or to set a suitable local grid voltage in the sense of a smart grid control.

Description

The invention relates to a low-maintenance and efficient device for mains voltage regulation and to a method for smart grid application for the purpose of voltage stabilization, e.g. in industrial areas. The device is suitable for stabilizing even strongly fluctuating mains voltages with little effort to the setpoint and also to lower overvoltages of more than 10% above the setpoint to values in the setpoint range. The invention can be used above all in the low-voltage range below 1000V, preferably for local 400V networks. The invention is used in particular to control the mains voltage, which is available to consumers by the setpoint of the voltage regulation is set accordingly.

Since around 2000, the task of voltage stabilization has been increasingly created by the decentrally feeding energy sources such as photovoltaic systems and wind power plants. At high power, these generate increased voltages of more than 440V up to 460V and more. And this although maximum 400V + 10% = 440V mains voltage are allowed. At the same time, electrical motors of pumps, compressors and other consumers connected to voltages of 380V + - 5%, ie for 360 ... 400V, are connected to these local networks. The higher voltages, which are now around 20% higher since the increased voltages are admitted, result in incorrect motor loads, reduced efficiency, shortened service life and increasing failure risk. In extreme cases, even the operating permit expires, as e.g. in explosion-proof devices. The value losses of the systems due to excess power consumption, shorter service life and increased maintenance costs caused by excessive mains voltages amount to up to 50 percent.

State of the art

From the prior art, it is known to the person skilled in the art to transform the mains voltage with a transformer to a desired value. For this purpose, electromagnetic devices are used which have at least one primary winding and at least one secondary winding. In a special case (autotransformer), the secondary winding can be partially identical to the primary winding.

New developments, such as the Magtech company from Norway 2007 ( DE60215381T2 ), use controllable transformers, which are marketed as controllable local power transformers (RONT) in the trade. These change the transformation ratio between medium voltage (10,000V) and low voltage (400V). For this purpose, very large and heavy winding goods are required, which is disadvantageous in terms of cost, size and weight. Far older technologies used controllable inductances prior to the introduction of the electronic controllers, in order to be able to steplessly lower the welding current in welding machines, for the purpose of improving the weld seam. For example, the invention of Messer Griesheim 1967 ( DE1690597 ).

Controllable inductors were also used around 1920, ie one hundred years ago for amplitude modulation. For example, the Pungs choke of Lorenz AG for the amplitude modulation of high-frequency radio signals (AM Radio).

problem

On the other hand, the control devices for voltage stabilization that are customary and available today use electronic regulators and electronic semiconductor components in order to keep the voltage constant. These highly loaded components have a very short lifespan compared to conventional local power transformers, a high failure risk and thus high maintenance costs and risks. Therefore, mostly only conventional local network transformers (ONT) are used. The consequence is that in the power lines to which the decentralized energy sources are connected, at high power very high voltages occur. These very high voltages fluctuate for a few minutes to a few hours, so should urgently be stabilized by appropriate control devices.

Object of the invention

The object of the present invention is to provide a low-maintenance, extremely reliable, durable and safe device for voltage stabilization and a method to compensate for the occurring too high and possibly. Too low voltages in the local network. The object is achieved by a device according to claim 1 and a method according to claim 8.

The inventive technology is characterized by the use of a winding material on a control magnetic core, which is brought by a control current partially or completely in the magnetic saturation, in combination with at least one, preferably with two oppositely flowing power windings whose magnetic circuit at least partially by the partially saturated Control magnetic core runs.

The device according to the invention 10 uses winding goods 11 . 13 . 23 For example, from copper or aluminum, to change over the influence of the electromagnetic field, the mains voltage UN to the regulated voltage UR. Characteristic is that on the winding material used for control 23 one from the control current 34 dependent complex voltage drop UN-UR occurs, which coincides with the magnitude of the control current 34 and with the intensity of the saturation field in the nucleus 43 drops. Maximum control current thus means minimal voltage drop across the power coils 11 and 12 , The device does not achieve the change in voltage by changing the semiconductor properties but by changing the electromagnetic properties. Nevertheless, the device is not a transformer, so has no primary and secondary winding.

The control unit 30 has at least one entrance 31 for the measuring voltage UR = 32 measured eg at terminal 15 , The controller is supplied with suitable supply voltage 35 , Via interface 37 the controller receives the setpoint 39 , For the purpose of smart grid control, the line 38 be a remote control line.

The control current 34 is in the preferred case a direct current and generated by the winding 23 in the control magnetic core 43 a DC premagnetization. Height of the control current 34 is set by a controller in such a way that the desired mains voltage results on the load side. If, for example, UN = 460V are applied to the mains, then such a high control current will occur 34 adjusted that close to UR = 400V on the consumer side, which is still acceptable for systems that require 380V + - 5%.

The regulator 30 is used to set the control current 34 the level of the consumer-side voltage UR is used as a basis compared to the setpoint 39 , In the event that the mains voltage is too high, the controller reduces the control current until the load-side voltage is lowered to the desired voltage value. This also reduces the saturation field in the control magnet core. In the event that the mains voltage drops, the controller increases 30 the control current 34 if necessary up to the maximum value. In a particularly preferred embodiment, the device is a transformer 60 upstream, for example, an autotransformer with which the mains voltage UN can be transformed up in the case of low line voltage. For example, by 10 percent of UN = 350V to UT = 385V. The device according to the invention 10 is this transformer 60 downstream and generates from this a regulated mains voltage of eg exact UR = 380V. The upstream transformer 60 is preferably only active when the mains voltage UN is too low, for example, when large consumers load the network and yet none of the decentralized energy sources is active, eg in the dark and simultaneous calm.

The activation of the upstream transformer 60 For example, it can be done before switching large consumers if they would find too little voltage. The deactivation of the upstream transformer 60 can take place when the need for the voltage boost no longer exists. However, in parallel there is the possibility of the subsequent voltage reduction by the electromagnetic device according to the invention 10 ,

embodiments

In the preferred embodiment, the electromagnetic control device consists of a multi-part magnetic core 40 from suitable core sheets. The magnetic core 40 has three recording areas 41 . 42 . 43 for winding goods (eg copper coils). A coil 23 , the control spool (S), encloses the middle of the reception areas 43 of the complex kernel 40 and generates there a controlling saturation field in the so-called control core 43 , The one receiving area 41 is from a first power coil (L1) 11 enclosed and the other recording area 42 from a second power coil (L2) 12 in push-pull. That is, for example, with the exact same type of winding but in the opposite direction of current. The magnetic circuits of the two power coils 11 . 12 each lead through the control core 43 , Due to the variable saturation of the control core 43 The electromagnetic state in the core material changes, and so does the inductance of the power coils 11 . 12 , The two power coils are via line 13 connected in series in the so-called push-pull and the phase of the mains voltage UN is at the input 14 connected. Regarding the neutral 50 is then at the exit 15 the device according to the invention 10 a regulated reduced voltage UR, wherein the voltage reduction of the height of the control current 34 is dependent. The height of the control current 34 becomes eg after specification of a desired value 39 via an electronic controller 30 , analog or digital, adjusted so that the desired voltage UR at the output 15 the device according to the invention 10 is produced. The device 10 can depending on the dimensions of the solenoid coils 11 . 12 . 23 and the magnetic cores 40 be designed for power of 10kVA, 30kVA, 100kVA or more. The masses of the winding goods and cores are considerably lower than those of comparable controllable transformers. In the exemplary embodiment, they are only about 15% of the mass of a conventional controllable or switchable 400V transformer for the same consumer power.

A particularly preferred embodiment also uses a durable and maintenance-free analog power controller 30 to the control current 34 the tax winding 23 increase or reduce until the desired voltage at the output is reached. The power supply 35 of the regulator 30 takes place eg by mains voltage UR or UN and an integrated power supply. The control signal for the setpoint 39 comes eg wirelessly or by cable 38 to the recipient 37 ,

Another particularly preferred embodiment uses, as an alternative to the analog controller, a digital PI controller to control the control current 34 for the saturation field in the control magnetic core 43 adjust so that the consumer, the device of the invention 10 upstream, exactly the desired voltage UR is reached.

Another preferred embodiment uses a ballast transformer 60 , particularly preferably in economy winding, in order first to transform the line voltage UN high to UT, for example by 10%, in order to then apply the highly transformed voltage UT through the device according to the invention 10 to regulate to a voltage value UR, which is in a particularly preferred case higher than the original value of the mains voltage UN.

• a) Aufnahme eines Spannungssignales 32 in den Regler 30, bevorzugt Aufnahme des Spannungs-Signals vom Ausgang 15 der Vorrichtung 10 oder alternativ Spannungssignal direkt vom Verbraucher.
• b) Falls Spannung 32 dort im Vergleich zum Sollwert 39 zu hoch: Reduzierung des Steuerstroms 34 durch Spule 23 zur Reduzierung der Sättigung im Steuerkern 43, zurück zu a)
• c) Falls Spannung 32 im Vergleich zum Sollwert 39 zu niedrig: Erhöhung des Steuerstroms 34 zur Erhöhung der Sättigung im Steuermagnetkern 43, zurück zu a)
• d) Falls Steuerstrom 34 gleich Maximalwert: der Spannungsabfall an Vorrichtung 10 ist minimal. Keine weitere Regelungsfunktion in Vorrichtung 10 möglich. Optional wird Vorschalt-Trafo 60 wird aktiviert.

The method of controlling the voltage provided includes the following steps:

• a) recording a voltage signal 32 into the regulator 30 , preferably recording the voltage signal from the output 15 the device 10 or alternatively voltage signal directly from the consumer.
• b) If voltage 32 there compared to the setpoint 39 too high: reduction of the control current 34 through coil 23 to reduce saturation in the control core 43 back to a)
• c) If voltage 32 compared to the setpoint 39 too low: increasing the control current 34 to increase the saturation in the control magnetic core 43 back to a)
• d) If control current 34 equal to maximum value: the voltage drop across the device 10 is minimal. No further control function in device 10 possible. Optionally, ballast transformer 60 is activated.

• e) Falls Steuerstrom 34 fast maximal oder maximal: Aktivierung des Vorschalt-Trafos 60 und Hochtransformation der Netzspannung UN auf UT
• f) Nun zurück zu a)
• g) Erfassung der Netzspannung UN. Falls diese wieder ansteigt: Deaktivierung des Vorschalt-Trafos 60 bei der nächsten Gelegenheit
• h) Nächste Gelegenheit ist bei stufenlos schaltbaren Trafos 60 sofort, bei nur leistungslos schaltbaren Trafos 60 der nächste leistungslose Fall, z.B. ein einer Arbeitspause des Verbrauchers.

The particularly preferred method for the device with ballast transformer additionally comprises the steps:

• e) If control current 34 almost maximum or maximum: Activation of the ballast transformer 60 and high transformation of the mains voltage UN to UT
• f) Now back to a)
• g) detection of the mains voltage UN. If this increases again: deactivation of the ballast transformer 60 at the next opportunity
• h) The next opportunity is with continuously variable transformers 60 Immediately, with only powerless switchable transformers 60 the next powerless case, eg a break in the work of the consumer.

LIST OF REFERENCE NUMBERS

10

 Electromagnetic device

11

 Power winding 1

12

 Power winding 2

13

Cable bridge L1 L2

14

 Voltage input on the mains side

15

 Voltage output on the consumer side

16

 internal connection of power coil L1

17

 internal connection power coil L2

23

 Control coil S

24

Ground for control voltage DC

25

Control voltage DC adjusted by SR control device 30

30

Control device for setting the control current 34 at terminal 25

31

 Connection for measuring signal AC voltage UR

32

Test lead Voltage measurement at terminal 15

33

Connection for control current 34 to the electromagnetic device

34

Control current DC for control coil 23

35

Power supply of the control device 30

37

Interface for setpoint signal 39

38

Transmission element for setpoint signal 39

39

Setpoint

40

 Magnet core assembled

41

Recording area for L1

42

 Recording area for L2

43

 Recording area for S and control magnetic core

50

neutral

51

 Reference neutral for mains voltage

52

 Reference neutral for standard voltage

60

ballast transformer

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 60215381 T2 [0004]
• DE 1690597 [0004]

Claims (9)

Device for voltage regulation, in particular on power grids, characterized in that it comprises the following components and components: a) Electromagnetic device ( 10 ) with control coil ( 23 ) on control magnetic core ( 43 ) for generating a saturation field in the control magnetic core ( 43 ), b) and at least one power coil ( 11 . 12 ) on a power magnetic core 41 . 42 with magnetic circuit passing through the control magnet core 43 runs, c) and complex magnetic core ( 40 ) for the guidance of the magnetic circuits of the winding goods ( 11 . 12 ) and ( 23 ) d) and device ( 30 ) for setting the control current ( 34 ) through the control coil ( 23 ) depending on setpoint ( 39 ) and the measured generated useful voltage ( 32 ), e) and connection of the local mains voltage (UN) or the optionally pre-transformed mains voltage (UT) to the device ( 10 ), in particular at the entrance ( 14 ) of the power coil ( 11 ) f) Connection of the consumer to the voltage (UR) leading output ( 15 ) of the power coil ( 12 ). Device according to claim 1, characterized in that regulation ( 30 ) the setpoint ( 39 ) and the voltage signal ( 32 ) and the control current ( 34 ) so high that the voltage measurement signal ( 32 ) as far as possible the desired voltage (UR), in particular by the control current ( 34 ) is reduced when the measured voltage ( 32 ) is higher than the setpoint ( 39 ). Device according to one of the preceding claims, characterized in that in each phase of the power network, pairs of power coils ( 11 ) and ( 12 ) are used in electromagnetic push-pull circuit, in particular the same number of turns, same winding geometry but opposite current direction and induction. Device according to one of the preceding claims, characterized in that a common magnetic core ( 40 ) is used with the recording areas ( 41 . 42 ) and ( 43 ) for the power coils ( 11 ) and ( 12 ) as well as for the control coil ( 23 ), whereby the control coil ( 23 ) in the reception area ( 43 ) between the two recording areas ( 41 ) and ( 42 ) of the power coils (L1, L2) is mounted, in particular in the middle of the three legs of the magnetic core ( 40 ). Device according to one of the preceding claims, characterized in that it has a combination with a regulator ( 30 ) for voltage regulation on a single-phase power line, the setpoint ( 39 ) according to the requirements of the consumer or the network (Smart Grid). Device according to one of the preceding claims, characterized in that three pairwise combinations of one electromagnetic device each ( 10.1 . 10.2 . 10.3 ) with regulating devices ( 30.1 . 30.2 . 30.3 ) are provided for voltage regulation on a three-phase power line, wherein the respective desired value of the three phases ( 39.1 . 39.2 . 39.3 ) according to the requirements of the consumer or the network, in particular in the sense of a smart grid regulation. Device according to one of the preceding claims, characterized in that it is combined with at least one upstream transformer ( 60 ), in particular autotransformer, which electromagnetically transforms the mains voltage (UN) to (UT), in particular raises, in particular by about 5 to 10 percent. Method for regulating a mains voltage on an AC voltage network for consumers, the following steps being carried out: a) detecting the AC voltage ( 32 ), especially at the network output ( 15 ) or directly at the consumer by the control device ( 30 ) b) comparing the detected voltage ( 32 ) with a setpoint ( 39 ) c) setting a control current ( 34 ), in particular direct current, for a control coil ( 23 ) as part of a device ( 10 ) according to claims 1 to 7 by reducing the control current ( 34 ), when the measured voltage ( 32 ) is too high and increasing the control current ( 34 ) if the measured voltage is too low. d) optional connection of a ballast transformer ( 60 ) in the event that the control voltage ( 34 ) is already raised very far or completely to the maximum value. Method according to claim 8, characterized in that the nominal value ( 39 ) for the regulating device ( 30 ) is given dynamically and temporally variable by a smart grid technology and the control current ( 34 ) is varied accordingly and the electromagnetic device ( 10 ) generates a corresponding complex voltage drop, so that the setpoint is reached as far as possible within the control limits.

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