DE102009030406A1 - Circuit arrangement for connecting maximum power point power source to power supply network of motor vehicle, has electronic switch, diode and inductor for controllably connecting power source with network in different power ranges - Google Patents

Abstract

The circuit arrangement has an electronic switch (309), a diode (311) and an inductor (312) for controllably connecting a maximum power point (MPP) power source (307) with a power supply network (301) in different power ranges. The diode is arranged parallel to the inductor. A closed loop control (306) detects the power ranges based on input signals (I, U) and controls, activates and deactivates the electronic switch, diode and the inductor based on the detected power ranges. An independent claim is also included for a method for connecting a power source to a power supply network.

Description

The The invention relates to a circuit and a method for connection a power source to a power grid as well as a vehicle with a such circuit.

In conventional vehicle power grids is a generator as Provided energy source, which is driven by an internal combustion engine. Often the generator is the only source of energy in the vehicle. With As the level of electrification increases, so does the electrical level Power requirement, so that there is a fundamental motivation, to harness additional energy sources in the vehicle.

Around reducing the vehicle's CO2 emissions are measures which optimize energy production (eg in the form of a "mild hybrid" vehicle) and / or an optimized generator control).

In addition to the said generator can in the vehicle other electrical energy sources are used. These additional sources of energy can the energy from the environment (eg solar radiation, temperature, Vibration, movement of the vehicle, etc.) win and remove not (like the generator) the energy from the primary fuel "fuel" of the vehicle. Examples for such Energy sources are: thermoelectric generator (TEG), photovoltaic modules, piezoelectric Crystals.

Such energy sources have the property that the amount of energy release is dependent on the output voltage. Since the energy is taken from the environment, the goal is to generate as much electrical energy as possible with these energy sources in order to relieve the generator in the best possible way and thus require less fuel to operate the generator. Show in this regard 1A and 1B Characteristics of so-called MPP (Maximum Power Point) energy sources, ie energy sources that have an optimal operating mode. 1A shows a characteristic 101 maximum electrical power depending on the voltage and the temperature and 1B shows a characteristic 102 maximum electrical power depending on the voltage and the energy radiation.

There These MPP energy sources vary greatly in terms of Often they are subject to regulated tensions electrical converter connected to the power cord of the vehicle. This is comparable z. B. with inverters used for connection used by photovoltaic systems to the electrical supply network or with regulated DC / DC converters for charging batteries (eg in mobile homes).

to Optimized use of MPP energy sources often become voltage transformers used with overlapping ones Voltage ranges can work. Such a voltage converter can have at least one boost converter and / or at least one buck converter exhibit.

Of the Use of such a voltage converter generates losses and supplies an undesirable thermal Contribution in the intended space. If necessary, separate Measures for cooling the components of the converter are provided. Here take the Losses of the converter with increasing efficiency too, as appropriate its components for a higher current carrying capacity and higher Blocking voltages must be designed.

It is also known, the MPP power source via a diode with the power onboard to connect and no separate regulation or adaptation (in the form of the voltage converter). However, this solution is in Split the possible voltage range and power range of the MPP power source significantly worse as the connection over the voltage converter.

The The object of the invention is the disadvantages mentioned above and in particular an efficient solution for connecting energy sources, z. From MPP energy sources in a vehicle.

These Task is performed according to the characteristics of independent claims solved. Further developments of the invention will become apparent from the dependent claims.

• – bei der in einem ersten Leistungsbereich die Energiequelle mittels eines ersten Elements geregelt mit dem Energienetz verbunden ist und
• – bei der mindestens in einem zweiten Leistungsbereich die Energiequelle mittels eines zweiten Elements ungeregelt mit dem Energienetz verbunden ist.

To achieve the object, a circuit for connecting a power source to a power grid is specified,

• - In which in a first power range, the power source is connected by means of a first element regulated to the power grid, and
• - Wherein the energy source is at least in a second power range unregulated by means of a second element connected to the power grid.

In this case, it is advantageous that, in the second power range, the energy source can be connected and / or connected to the energy network efficiently and inexpensively via the second element. This is especially true in the case where the second power range covers a higher power source than the first power range. In this case, the first element, the allows a regulated connection of the power source to the power grid, designed for the lower power range. This brings in terms of more complex control cost advantages and benefits in terms of space and cooling requirements.

A Further education is that the first element is a converter, in particular a voltage converter is.

• – einen Hochsetzsteller;
• – einen Tiefsetzsteller;
• – einen Hochtiefsetzsteller.

Another development is that the converter comprises at least one of the following components:

• A boost converter;
• A buck converter;
• - a high stepper converter.

Also can special transducers are used, for. B. Boost, Buck, Sepic, Cuk, and derived topologies such as flyback converters, push-pull, forward converters. Combinations of the mentioned transducers can also be used.

Especially It is a development that the second element is a diode, a controlled diode or switching element (relay) or a power transistor, z. B. comprises a MOSFET.

Also It is a training that the energy source in the first Performance area and in the second area of performance over the second element is connected to the power grid.

Thereby the second element can be a failsafe in terms of a potential Ensure defect of the first element. This ensures that even if the first element fails, the Energy source (in the first power range) with the power grid connected is. The functionality is therefore guaranteed even in the first performance range, even if the first element does not work.

Further It is a development that the second element parallel to the first element is arranged.

A next Continuing education is that the first performance area Lower power range than the second power range.

Consequently For example, the second element (eg, the diode) may be for a high power range the energy source, whereas the first element (z. B. the voltage converter) efficient and inexpensive for a low power range the power source is designed.

A Embodiment is that a scheme is provided, based depending on them of at least one input signal, the first element and / or the second element is controllable.

The Control can z. B. in the form of a microcontroller or microprocessor be realized in hardware, firmware or software. Also, the Control in digital or be implemented in analog technology.

in this connection can be dependent of at least one input signal of the control the first element, z. As the converter, suitably activated, activated and / or deactivated become. It is also possible that the second element, z. As the diode, activated or deactivated becomes. This can be achieved by making the scheme the current path the diode turns on or locks accordingly.

Preferably is the first element, z. The transducer, controlled clocked, allowing an adjustment of the energy level the power source is made according to a predetermined size.

Especially the diode can always be active and only the converter is using the control is driven or disabled.

• – eine Spannung der Energiequelle;
• – einen Strom, der von der Energiequelle bereitgestellt wird.

An alternative embodiment is that at least one input signal of the control comprises at least one of the following signals:

• A voltage of the power source;
• A current provided by the power source.

A next Design is that dependent from the at least one input signal by means of the control Diagnostic function feasible is.

Consequently the scheme may be arranged such that at least one the input signals is evaluated appropriately and z. B. by detection a change by more than a predetermined threshold, a predetermined action is triggered. So could z. B. a defect (eg a voltage or power dip) of the power source detected become. Also, by means of suitable input signals, a function the diode or transducer (generally the first element and / or of the second element) become. Optionally, the scheme may have an emergency deactivation the circuit and / or generate an error message and display or appropriate hand off. For example, the controller may include such a diagnosis Forward the bus system to a central component of a vehicle, the dependent initiates a predefined action from the type of diagnosis or performs.

Also It is an embodiment that the scheme is the first power range and the second power range based on the at least one input signal detected and dependent from the detected power range, the first element and / or the second element is activated, activated or deactivated.

• – einen thermoelektrischen Generator;
• – ein Photovoltaik-Modul;
• – piezoelektrische Kristalle.

A development consists in that the energy source comprises at least one of the following components:

• A thermoelectric generator;
• A photovoltaic module;
• - piezoelectric crystals.

A additional Embodiment is that the connection of the power source to a Energy network, in particular to an energy on-board network of a vehicle, he follows.

The The above object is also achieved by a vehicle comprising a circuit as described herein.

• – bei dem in einem ersten Leistungsbereich die Energiequelle mittels eines ersten Elements geregelt mit dem Energienetz verbunden wird und
• – bei dem mindestens in einem zweiten Leistungsbereich die Energiequelle mittels eines zweiten Elements ungeregelt mit dem Energienetz verbunden wird.

The above object is also achieved by a method for connecting a power source to a power grid

• - In which in a first power range, the power source is connected by means of a first element regulated to the power grid, and
• - In which at least in a second power range, the energy source is connected by means of a second element unregulated to the power grid.

The Method is by means of a control (or any control unit) feasible. Such a regulation can - like embodied herein - in hardware or software realized.

A Embodiment is that by means of a regulation dependent on at least one input signal of the controller, the first element and / or the second element is activated, activated or deactivated.

Also is it a way that by the scheme monitoring and / or diagnosis of the first element and / or the second element.

The other described approaches apply to the procedure accordingly.

embodiments The invention are illustrated below with reference to the drawings and explained.

It demonstrate:

2 a schematic course of a system efficiency η when connecting the MPP energy source (eg a thermoelectric generator) by means of a diode and when connecting the MPP energy source by means of a regulated DC / DC converter as a function of the power P of the system;

3 a circuit arrangement for connecting an MPP power source to an energy on-board network, z. B. a motor vehicle, wherein a controller activates or deactivates a converter depending on the power range of the MPP power source or the optimized efficiency; if the converter is inactive, the MPP energy source is coupled via a diode to the power supply system;

4 an alternative circuit arrangement for connecting a MPP power source to an energy board network, wherein the diode is arranged to bypass the converter.

Of the The approach proposed here combines in a particularly efficient way the advantages of an unregulated and a regulated connection of a MPP energy source to an energy board network z. B. a vehicle.

So becomes a regulated converter (eg a voltage converter, boost converter, Buck converter, or combinations thereof) for a first power range the MPP energy source is used, allowing the energy of the MPP energy source through the transducer is fed into the power cord network.

For one second power range of the MPP power source is the converter switched off and the supply of energy of the MPP energy source in the power cord network is done directly, z. B. via a controlled switch or over a diode.

Of the first power range of the MPP power source preferably corresponds a low power area and the second power area the MPP power source preferably corresponds to a high range Power. In particular, you can the first power range and the second power range one cover the entire power range of the MPP energy source.

Also Is it possible, that correspondingly more power ranges are provided, in which a different connection of the MPP energy source to the Power onboard network takes place. For example, different converters can be different Service areas be provided.

2 shows a schematic course of a system efficiency η when connecting the MPP power source (eg, a thermoelectric generator) by means of a diode (Graph 201 ) and when connecting the MPP power source by means of a regulated DC / DC converter (Graph 202 ) depending on the power P of the system. In the power range up to approx. 50 W, the connection to the power supply system via the converter is significantly more efficient, and in the power range above approx. 50 W, the connection of the MPP energy source via a diode is a solution optimized for efficiency.

3 shows a circuit arrangement for connecting an MPP power source to an energy on-board network, z. B. a motor vehicle, wherein a controller activates or deactivates a converter depending on the power range of the MPP power source or the optimized efficiency. If the converter is inactive, then the MPP energy source is coupled via a diode to the power supply system.

3 shows an energy board network 301 in which a starter 302 , a generator 303 , a battery 304 and a consumer 305 are connected in parallel. The positive pole of the energy system 301 is with a node 314 connected.

An MPP energy source 307 is with her positive pole with a knot 315 connected, the negative pole is grounded. An inductance 312 lies between the node 315 and a node 316 , A diode 311 is between the node 316 and the node 314 arranged, the cathode of the diode 311 in the direction of the knot 314 shows. A capacitor 308 (eg representative of an EMC filter) is on the one hand with the node 314 and on the other hand connected to ground. A capacitor 313 (eg representative of an EMC filter) is on the one hand with the node 315 and on the other hand connected to ground. For example, the EMC filters may include two capacitors and one inductor and / or be implemented in a PI topology. An electronic switch 309 is on the one hand with the node 316 and on the other hand connected to ground. The electronic switch 309 can z. B. be designed as a transistor, a MOSFET, an IGBT or a triac. The electronic switch 309 will have a signal 310 a regulation 306 driven. The regulation 306 obtains a voltage information U of the voltage of the MPP power source 307 and current information I from the MPP power source 307 fed electricity. Depending on the voltage information U and / or the current information I generates the control 306 a corresponding signal 310 for controlling the electronic switch 309 ,

Thus, the MPP power source becomes 307 via a boost converter to the power cord network 301 tethered. In the low power range, the DC / DC converter is operated clocked and with the help of the control 306 set. Once the MPP power source 307 generates so much energy that a connection via the diode 311 achieved a better efficiency (as the connection via the converter), the DC / DC converter by means of the scheme 306 off. The MPP energy source 307 then feeds unregulated via the diode 311 Energy in the power cord network 301 one.

It is advantageous that only the diode 311 and the current carrying capacity of the inductance 312 for the maximum occurring current flow of the MPP energy source 307 must be designed. The electronic switch 309 , the capacitors 308 and 309 (EMC filter) and the core material for the inductance 312 need only for the low power range (in the example of 2 smaller (or equal) 50 W) and can thus be integrated in a small space.

The regulation 306 can be realized for example as a microcontroller.

4 shows an alternative circuit arrangement for connecting an MPP power source to an energy onboard, the diode is now arranged to bypass the converter and any existing EMC filters.

4 shows again the power cord net 301 that already related to 3 is described. The positive pole of the energy system 301 is with a node 414 connected.

An MPP energy source 407 is with her positive pole with a knot 415 connected, the negative pole is grounded. An inductance 412 lies between the node 415 and a node 416 , A diode 411 is between the node 415 and the node 414 arranged, the cathode of the diode 411 in the direction of the knot 414 shows. A capacitor 408 (eg representative of an EMC filter) is on the one hand with the node 414 and on the other hand connected to ground. A capacitor 413 (eg representative of an EMC filter) is on the one hand with the node 415 and on the other hand connected to ground. For example, the EMC filters may include two capacitors and one inductor and / or be implemented in a PI topology. An electronic switch 409 is on the one hand with the node 416 and on the other hand connected to ground. Between the node 414 and the node 416 is a switch 417 , which is designed in particular as an electronic switch, arranged. The electronic switch 409 or the electronic switch 417 can z. B. be designed as a transistor, a MOSFET, an IGBT or a triac. The electronic switch 409 will have a signal 410 a regulation 406 driven. The regulation 406 receives a voltage information U of the voltage of MPP energy source 407 and current information I from the MPP power source 407 fed electricity. Depending on the voltage information U and / or the current information I generates the control 406 a corresponding signal 410 for controlling the electronic switch 409 ,

Unlike the in 3 shown embodiment is in particular the diode 411 in 4 arranged bridging the transducer. It is advantageous that the losses of the inductance 412 , the converter and any existing EMC filters are reduced.

To additionally reduce the losses, the diode can 411 as a controlled diode (eg by means of a MOSFET). The control of the controlled diode can by means of the control 406 respectively.

Also it is beneficial that the scheme 406 for diagnosis z. As the MPP power source, the diodes or the transducer can be used. Thus, changes in the signals U and I z. B. indicate defective functions, the scheme 406 can in this case z. B. have a function for (eg, galvanic) separation of the MPP power source from the power onboard network.

The circuit according to 4 has the further advantage that even in case of failure of the scheme 406 Furthermore, an unregulated supply of electrical energy from the MPP power source is possible in the power onboard network.

Other advantages:

Of the Effort for a converter, in particular a DC / DC converter, for connecting an MPP power source is significantly reduced by means of the solution proposed here. So can the converter as well as possible EMC filter for a low current carrying capacity be interpreted, which is beneficial to a low weight, low Requirements for the installation space as well as the reduced required cooling capacity effect. Such a converter saves costs compared to a Converter, too, for the full ampacity would have to be designed.

Consequently results in a beneficial increase in system efficiency. Also, in combination with z. B. a diode to create a redundancy, so that even if the converter fails, the functionality of the feed the energy from the MPP energy source preserved.

101

curve

102

curve

201

efficiency the diode connection

202

efficiency the DC / DC converter connection

301

Energy board network

302

starter

303

generator

304

battery

305

consumer

306

regulation

307

MPP power source

308

capacitor (or EMC filter)

309

electronic switch

310

Signal (to control the electronic switch 309 )

311

diode

312

inductance

313

capacitor (or EMC filter)

314

node

315

node

316

node

406

regulation

407

MPP power source

408

capacitor (or EMC filter)

409

electronic switch

410

Signal (to control the electronic switch 309 )

411

diode

412

inductance

413

capacitor (or EMC filter)

414

node

415

node

416

node

417

switch

Claims (17)

Circuit for connecting an energy source ( 307 ; 407 ) to a power grid ( 301 ), - in which, in a first power range, the energy source ( 307 ; 407 ) by means of a first element ( 309 . 312 ; 409 . 412 ) regulated with the energy network ( 301 ) and - at least in a second power range, the energy source ( 307 ; 407 ) by means of a second element ( 311 ; 411 ) is unregulated connected to the power grid. A circuit according to claim 1, wherein the first element ( 309 . 312 ; 409 . 412 ) is a converter, in particular a voltage converter. The circuit of claim 2, wherein the converter is at least includes one of the following components A boost converter; - one Step-down converter; - one High step-down converter. Circuit according to one of the preceding claims, in which the second element ( 311 ; 411 ) a diode, a controlled diode or a MOSFET. Circuit according to Claim 4, in which the energy source ( 307 ; 407 ) in the first power range and in the second power range via the second element ( 311 ; 411 ) is connected to the power grid. Circuit according to one of Claims 4 or 5, in which the second element ( 311 ; 411 ) parallel to the first element ( 309 . 312 ; 409 . 412 ) is arranged. Circuit according to one of the preceding claims, in the first power range is a lower power range as the second service area. Circuit according to one of the preceding claims, in which a regulation ( 306 ; 406 ) is provided on the basis of which, depending on at least one input signal, the first element ( 309 . 312 ; 409 . 412 ) and / or the second element ( 311 ; 411 ) is controllable. Circuit according to Claim 8, in which the at least one input signal (I, U) of the control ( 306 ; 406 ) comprises at least one of the following signals: a voltage of the power source; A current provided by the power source. Circuit according to one of Claims 8 or 9, in which, depending on the at least one input signal (I, U), by means of the regulation ( 306 . 406 ) a diagnostic function is feasible. Circuit according to one of Claims 8 to 10, in which the control ( 306 ; 406 ) detects the first power range and the second power range on the basis of the at least one input signal (I, U) and, depending on the detected power range, the first element ( 309 . 312 ; 409 . 412 ) and / or the second element ( 311 ; 411 ), activates or deactivates. Circuit according to one of the preceding claims, in which the energy source ( 307 ; 407 ) comprises at least one of the following components: a thermoelectric generator; A photovoltaic module; - piezoelectric crystals. Circuit according to one of the preceding claims, wherein the connection of the energy source ( 307 ; 407 ) to a power grid ( 301 ), in particular to an energy on-board network of a vehicle takes place. Vehicle with a circuit according to one of the preceding Claims. Method for connecting an energy source to a Energy grid, - at in a first power range, the power source by means of a first element is connected to the power grid and - in which at least in a second power range, the energy source by means of a second element is connected unregulated to the power grid. The method of claim 15, wherein by means of a Regulation dependent of at least one input signal of the controller, the first element and / or the second element is activated, activated or deactivated. A method according to claim 16, wherein by means of Regulation a monitoring and / or diagnosis of the first element and / or the second element.