WO2014198821A1

WO2014198821A1 - Converter unit with a common switch element for braking chopper, and boost converter

Info

Publication number: WO2014198821A1
Application number: PCT/EP2014/062223
Authority: WO
Inventors: Jochen Hantschel
Original assignee: Jochen Hantschel
Priority date: 2013-06-13
Filing date: 2014-06-12
Publication date: 2014-12-18
Also published as: DE102013106173A1

Abstract

The invention relates to a converter unit (10; 10a) comprising at least one inverter (12; 12a) for supplying a direct voltage applied on the input side to at least one output-side load (14; 14a), comprising at least one braking chopper unit (20; 20a) which is connected between at least two poles of the inverter (12; 12a) on the input side, comprising at least one feed circuit (30; 30a) which is provided in order to provide energy to the inverter (12; 12a) on the input-side from a photovoltaic source (32; 32a), and comprising at least one control unit (26; 26a) for controlling at least the feed circuit (30; 30a). The inverter unit (10; 10a) has a rectifier (16; 16a) which is provided in order to rectify at least one phase (41, 42, 43; 41a, 42a, 43a) of a network source (40; 40a) and to supply said phase to the inverter (12; 12a) on the input side. The feed circuit (30; 30a) and the braking chopper unit (20; 20a) are at least partly integrally formed.

Description

INVERTER UNIT WITH A COMMON SWITCHING ELEMENT FOR BRAKE CHOPPER AND

HOCHSETZSTELLEFI

State of the art

The invention relates to a converter circuit according to the preamble of claim 1.

5 It is known to supply inverters with photovoltaic energy.

The object of the invention is in particular to provide a generic device with improved properties in terms of high efficiency, component savings and / or cost savings. The object is achieved by the features of claim 1, while advantageous embodiments and 0 developments of the invention can be taken from the dependent claims.

Advantages of the invention

The invention is based on a converter unit with at least one inverter for supplying at least one output-side load from the DC voltage present on the input side, with at least one brake disc unit which

15 is connected on the input side between at least two poles of the inverter, with

at least one feed-in circuit which is provided to provide energy from at least one photovoltaic source to the inverter on the input side, and with at least one control unit for controlling the feed circuit.

It is proposed that the converter unit has at least one rectifier, which is intended to provide at least one phase, in particular three phases, one

To rectify the grid source and the input side to provide the inverter, the feed circuit and the brake disc unit are at least partially formed in one piece. An "inverter" is to be understood as meaning, in particular, a unit which is intended to supply a DC voltage present on the input side in at least one AC voltage, in particular in multiphase AC voltages, , -

to change. A "DC voltage" is to be understood in particular as meaning a voltage which has a waviness which is less than 50%, in particular less than 30%, advantageously less than 15%, preferably less than 5%.

In particular, the consumer is designed as a motor, in particular a material and / or passenger transport means, in particular an escalator and / or an elevator. Alternatively, embodiments of the consumer as a pump or other unit that requires an inverter conceivable. A "brake chopper unit" is to be understood in particular as a unit which is provided in at least one operating state of input poles of the inverter in at least one direction, in particular a first direction, which is directed in particular against a voltage applied in normal operation, at least substantially short circuited and / or in at least one direction, in particular a second

Direction, which is directed in particular in the direction of a voltage applied in a normal operation, to connect with contacts which are adapted to connect a braking resistor and / or to which a braking resistor is connected. In particular, the brake disc unit has at least one rectifier element, in particular a diode. Advantageously, the brake disc unit has at least one switching element for the controlled release of a brake path. In particular, the brake chipper unit is provided to a structure of an input side on

Inverter voltage applied, in particular due to inductive effects and / or feedback effects of the consumer to avoid. In particular, the brake chipper unit has at least one sensor element for a measurement of a

Voltage across the input side poles of the inverter. In particular, the control unit is provided, in the event of detection of a voltage exceeding a maximum value, in particular configurable by an operator, to activate the switching element in order to release the braking path. Under one

"Feed-in circuit" is to be understood in particular as a circuit which is intended to convert a power provided by at least one photovoltaic source into a form required by the inverter, in particular a minimum voltage

Input interface, which is intended to be connected to the photovoltaic source. Advantageously, the feed circuit has at least one buffer capacity, which is connected in particular parallel to the input interface, whereby in particular a high efficiency and / or a uniform power extraction can be achieved , ,

can. In particular, the feed circuit is designed as an up and / or down converter. In particular, the feed circuit has at least one switching element. In particular, the control unit is provided to a desired input voltage target by varying the frequency and / or duty cycle of a

To set control signal of the switching element. In particular, the

Feed circuit at least one sensor element, which is intended to determine a voltage applied to the input interface. Advantageously, the feed circuit has at least one sensor element which is provided to measure a current taken from the at least one photovoltaic source. In particular, the control unit is provided to vary a switching frequency and / or a duty cycle of the switching element in order to find an optimal operating point, in particular a maximum power operating point of the photovoltaic source, wherein the

Control unit is advantageously provided to avoid exceeding a maximum value of the output voltage, in particular 750 V. The predefined maximum value is determined, in particular, by the components of the feed circuit and / or the inverter used and / or by a consumer operated by the inverter. The control unit preferably comprises a computing unit and, in particular in addition to the computing unit, a memory unit with a control and / or regulating program stored therein, which is intended to be executed by the computing unit. In particular, the rectifier is designed as a polyphase rectifier. In particular, the rectifier is provided to supply voltages of different phases in a common DC link. In particular, an output side of the rectifier and an input side of the inverter are connected by means of a DC intermediate circuit into which the feed circuit feeds energy of the photovoltaic source. It is to be understood, in particular, that the units have at least one, in particular at least two, advantageously at least three common elements which are a component, in particular a functionally important component, of both units. should be understood in particular specially programmed, designed and / or equipped. Under the fact that an object is intended for a particular function, should be understood in particular that the object that particular function in at least one application and / or

Operating condition fulfilled and / or executes. It can achieve a connection of a network source by means of the rectifier and in particular an independence of solar energy - -

become. In particular, load peaks can be compensated. In particular, a backflow of energy from the photovoltaic source into the network source can be effectively prevented by the rectifier. Furthermore, a simple configuration of a converter unit and, in particular, a saving of components and a cost saving can be achieved. By a direct coupling of the photovoltaic source by means of a single inverter stage with the consumer, a high efficiency can be achieved. In particular, it is possible to dispense with additional electronics and / or safety means for feeding energy of the photovoltaic source into a mains source.

Advantageously, the brake chopper unit and the feed circuit at least one common switching element, wherein the control unit is provided, in at least one operating state, the switching element to a setting of

To actuate the operating point of the photovoltaic source and to activate in at least one other operating state, the switching element to a release of a braking path. Including that the switching element is provided for "release of the brake path" is to be understood in particular that the switching element input contacts the at least one inverter unit with contacts for at least one

Braking resistor connects. Advantageously, the brake disc unit and the

Feed circuit on at least a common rectifier element. In particular, this is the rectifier element provided to be connected in parallel to the braking resistor, in particular as a freewheeling circuit. In particular, a component and / or cost savings can be achieved.

Advantageously, the feed circuit has at least one inductance which is arranged between the switching element and the buffer capacitor. Preferably that forms

Switching element together with the inductor from an up-converter. In particular, a first pole of the inductance is connected to one pole of the buffering capacity.

Advantageously, a second pole of the inductance is connected to a first pole of the switching element and a first pole of a rectifier element, wherein advantageously second poles of the rectifier element and the switching element to different

Input-side poles of the inverter are connected. In particular, a high degree of efficiency can be achieved.

In an advantageous embodiment, the brake chopper unit is connected on the output side between two poles of the rectifier. In particular, the brake chipper unit is to , ,

provided to avoid a structure of an output voltage applied to the rectifier, in particular due to inductive effects and / or feedback effects of the consumer.

It is also proposed that the converter unit has a sensor unit which is provided to measure at least one input-side voltage of the inverter. In particular, the control unit is provided to at least one characteristic of the feed circuit, in particular a frequency and / or a duty cycle of a control signal of the switching element, to at least one by the sensor unit

adjust measured voltage. In particular, the control unit is provided to deactivate a feed when a voltage is detected by means of the sensor unit, which exceeds a predetermined maximum value. In particular, improved safety can be achieved.

Furthermore, it is proposed that the control unit is provided to the

To address such a feed circuit, in particular by means of a frequency-modulated and / or tastgradmodulierten signal that this generates a compensation signal, so that an input side of the inverter voltage applied at least partially, in particular steadily, at least substantially constant,

in particular less than 10%, advantageously less than 3%, particularly advantageously less than 1%, preferably less than 0.3%, varies. In particular, the control unit is provided for fluctuations, in particular at least periodic fluctuations of the voltage, in particular caused by superposition effects of the rectifier, the inverter and / or by feedback effects of the consumer,

compensate. In particular, a part of the compensation signal has a frequency which corresponds to a multiple, in particular a double or a six times, the frequency of the phase of the network source. In particular, the control unit is intended to interrupt the compensation signal regularly, in particular periodically, to a phase position and / or a strength of the. By the

Compensation signal to be corrected to correct voltage fluctuation. In a further embodiment, it is conceivable that the sensor unit at least one

Sensor element which is provided to determine at least one phase position of at least one phase of the mains source to the compensation signal with the

Synchronize voltage fluctuation. In particular, a strength of on the - -

Mains source retroactive harmonics, which arise in particular by superimposing the rectified signals of several phases of the network source can be reduced. In particular, a good, in particular steady and / or low-interference,

Energy supply can be achieved. drawings

Further advantages emerge from the following description of the drawing. In the drawings, an embodiment of the invention is shown. The drawings, the description and the claims contain numerous features in combination. The person skilled in the art will expediently also consider the features individually and combine them into meaningful further combinations.

Show it:

Fig. 1 shows a converter unit according to the invention and

Fig. 2 shows an inventive system for reconfiguration

conventional inverter. FIG. 1 shows a circuit diagram of a converter unit 10 according to the invention

Inverter unit 10 has an inverter 12 for supplying a

output side consumer 14 of the input side applied DC voltage. The inverter 12 is configured as a three-phase inverter and has a B6 configuration of semiconductor switching elements. Furthermore, the converter unit 10 has a rectifier 16 for rectifying three input-side phases 41, 42, 43 of a network source 40. Output-side poles of the rectifier 16 are connected via a DC voltage intermediate circuit 18 with input-side poles of the inverter 12. The rectifier 16 has a B6 configuration of diode rectifier elements with upstream choke coils. Furthermore, the rectifier 16 has a Vorladeschaltung to one on the

DC buffer 18 arranged buffer capacity before starting to load slowly over resistors before the buffer capacity directly to the

Rectifier unit is coupled. The buffer capacity is part of the

Inverter 12 and not shown explicitly. , ,

The converter unit 10 has a brake chopper unit 20, which is connected on the input side between two poles of the inverter 12. The brake chipper unit 20 is formed by a series connection of a diode-shaped rectifier element 22 and a switching element 24. The switching element 24 is formed by a power transistor. Furthermore, the converter unit 10 has a feed circuit 30, which is provided to provide energy from a photovoltaic source 32 to the inverter 12 on the input side. The feed circuit 30 has an input interface 31 for connecting the photovoltaic source 32. Furthermore, the feed circuit 30 has a buffer capacitor 33, which is connected between the contacts of the input interface 31. The feed circuit 30 is designed as a step-up converter. The

Feed circuit 30 and the brake chipper unit 20 are partially formed in one piece and have a common switching element 24 and a common rectifier element 22. The brake chipper unit 20 is completely formed by elements that are part of the feed circuit 30. The converter unit 10 has a control unit 26 for controlling and / or regulating the feed circuit 30 and the brake chopper unit 20. The control unit 26 is provided to control the switching element 24 in one operating state for setting an operating point of the photovoltaic source 32 and in another

Operating state to activate the switching element 24 to a release of the brake path. The control unit 26 is further provided to control the inverter 12.

The converter unit 10 has a sensor unit 50. The sensor unit 50 has a first sensor element 51 which is provided to measure an input-side voltage of the inverter 12, that is to say a voltage of the DC voltage intermediate circuit 18. Furthermore, the sensor unit 50 has a second sensor element 52, which is provided to supply a voltage across the input interface 31 of FIG

Feed circuit 30 to measure. The sensor unit 50 has a third sensor element 53, which is provided to measure a current taken from the photovoltaic source 32.

The feed circuit 30 has an inductance 34 which is arranged between the switching element 24 and the buffer capacitor 33. The inductance 34 forms with the

Switching element 24, the third sensor element 53 and the photovoltaic source 32 and / or the buffer capacitor 33 is a closed circuit. A first pole of the - -

Switching element 24 is connected to a second input side pole of the inverter 12. A second pole of the switching element 24 is connected to a pole of the inductor 34 and a first pole of the rectifier element 22. A second pole of the rectifier element 22 is connected to a first pole of the inverter 12. During operation of the feed circuit 30, the closed circuit comprising the switching element 24 and the buffer capacitor 33 or the photovoltaic source 32 is regularly separated and connected by means of the switching element 24. In the connected state, the inductance 34 is magnetically charged due to the short-circuit effect and in the disconnected state, the inductance 34, the charged energy due to self-induction with increased voltage in the DC voltage intermediate circuit 18 from. The delivery is carried out with the same polarity for feeding the rectifier 16.

The control unit 26 is provided to adapt a characteristic of the feed circuit 30 to a voltage measured by the sensor unit 50. The control unit 26 is provided to vary a frequency of the control of the switching element 24 of the feed circuit 30, so that it generates a compensation signal, so that a voltage applied to the input side of the inverter 12 is at least substantially constant. The control unit 26 is intended to be replaced by the

Sensor element 51 measured voltage fluctuations, in particular harmonics, which occur by rectifier superposition, by means of variation of the frequency of

Balance switching element 24 of the feed circuit 30. Part of the

Compensation signal in this case has a frequency which corresponds to a multiple, in the case of a three-phase rectifier six times, the frequency of the phases 41, 42, 43 of the network source 40, whereby harmonics are suppressed.

In order to ensure a synchronization of the compensation signal and at least the periodic voltage fluctuations, the compensation signal is interrupted regularly to re-measure a phase position of the voltage fluctuations and adjust the compensation signal accordingly.

Alternatively, it is conceivable that the sensor unit has at least one sensor element which measures at least one frequency, phase position, current intensity and / or voltage of at least one phase of the mains source connected to the rectifier, wherein the - -

Control unit is provided to determine a compensation signal from these measurements, and to feed accordingly via the feed circuit.

Furthermore, the control unit 26 is provided to stop a timing of the switching element 24 upon detection of an overvoltage, such as a voltage greater than 750 V, for example by feedback from the consumer 14, and thus a

Infeed to stop or at least limit.

In an alternative embodiment, it is conceivable that the converter unit has at least one braking resistor, which is connected in particular via an additional switching element, parallel to the rectifier element of the brake path, wherein advantageously the additional switching element is designed as a changeover switch, which either the

Braking resistor or the inductance to the rectifier element and the switching element connects. Advantageously, the control unit is provided, when a

Overvoltage to disconnect the photovoltaic source of the DC voltage intermediate circuit and to couple the braking resistor for reducing the overvoltage, wherein a compound is switched active via the switching element of the braking path.

In further embodiments, it is conceivable that the inverter and / or the rectifier are designed for a different number of phases and / or are of a different type. Furthermore, it is conceivable that more than one inverter for supplying in each case at least one consumer to a common

DC link are connected. Furthermore, it is conceivable that a plurality of input interfaces for connecting a plurality of photovoltaic sources are present, wherein these input interfaces in each case at least one own

Have feed circuit.

Furthermore, embodiments are conceivable in which the brake chopper unit, which is part of the feed circuit, is formed by a half-bridge circuit, in particular a MOSFET half-bridge, in particular in combination with a rectifier element. In such an embodiment, it is further conceivable to use the feed circuit or the brake disc unit bidirectional. In particular, it is used in a third operating mode to feed one, in particular a mechanical and / or electrochemical, energy store from the photovoltaic source

to store excess energy. - -

Furthermore, embodiments are conceivable which have a plurality of brake chopper units, which are each part of different feed circuits, wherein the

Feed circuits advantageously each have separate inductors. Advantageously, the feed circuits are driven out of phase in order to stabilize an energy extraction from the photovoltaic source.

In a further embodiment, the converter unit advantageously has at least one insulation measuring unit, which is provided to provide a, in particular common, degree of isolation of at least the photovoltaic source, the rectifier and / or the

Inverter and the consumer to determine. Advantageous is the

Vorladeschaltung and / or another isolation circuit provided to a

Isolation measurement a, preferably galvanic, separation of the intermediate circuit from the mains source, in particular a separation of the intermediate circuit of the

Rectifier unit perform.

Advantageously, the converter unit has at least one fault current sensor, which is in particular provided to measure at least one difference of current flowing into and out of the photovoltaic source and / or the rectifier unit. In particular, the control unit is provided to exceed a

predetermined limit value of the fault current and / or when exceeding a predetermined limit value for an increase of the fault current, an operation of the

Adjust rectifier and / or the inverter and / or advantageous to perform a separation of the DC voltage intermediate circuit from the mains source.

FIG. 2 shows a further exemplary embodiment of the invention. The following descriptions are essentially limited to the differences between the exemplary embodiments, wherein reference can be made to the description of the embodiment of FIG. 1 with regard to components, features and functions that remain the same. To distinguish the embodiments, the letter a to the

Reference numeral of the embodiment in Figure 2 attached. With regard to like-named components, in particular with regard to components with the same reference numerals, can in principle also to the drawings and / or the description of the

Embodiment of Figure 1 are referenced. - -

FIG. 2 shows a conventional reprogrammable converter 1 1 a having a feed module 13 a and a software module 27 a for an inventive

Inverter unit 10a is reconfigured. The software module 27a replaces and / or extends an existing operating program of a control unit 26a of the inverter 11a. The converter 1 1 a has a rectifier 16 a, which is intended to rectify current of a network source 40 a and feed it into a DC voltage intermediate circuit 18 a. The inverter 1 1 a has an inverter 12 a, the to

is provided to remove power to the DC voltage intermediate circuit 18a, to convert into an alternating current and supply a consumer 14a. The control unit 26a drives the inverter 12a. Furthermore, the control unit 26a controls the

Rectifier 16a. The inverter 1 1 a has a brake disc unit 20 a. The brake chipper unit 20a is formed by a switching element 24a and a diode-shaped rectifying element 22a, which are connected in series between input contacts of the inverter 12a. Contacts of the brake chipper unit 20a form an extension interface 62a. The control unit 26a has control inputs 66a.

The feed module 13a has an input interface 31a for connecting a photovoltaic source 32a. Furthermore, the feed module 13a has a buffer capacity 33a which is connected between contacts of the input interface 31a. The

Feed module 13a has an inductance 34a, which is connected between a first contact of the input interface 31a and a first contact of an output interface 60a of the feed module 13a. Furthermore, second contacts are the

Input interface 31 a and the output interface 60a connected to each other. The feed module 13a has sensor elements 52a, 53a. A first of the sensor elements 52a is designed as a voltage sensor which is provided to measure a voltage across the input interface 31a. A second one of the sensor elements 53a is designed as a current sensor which is provided to measure a feed-in current which is output via the contacts of the output interface 60a. Signals of

Sensor elements 52a, 53a are conducted to a sensor interface 64a. The contacts of the expansion interface 62a of the inverter 1 1 a, are to

intended to be connected to contacts of the output interface 60a. contacts - -

the control inputs 66a are intended to be connected to contacts of the sensor interface 64a.

The inductance 34a of the feed module 13a and the brake chopper unit 20a of the converter 1 1 a together form a feed circuit 30a, wherein the

Software module 27a is provided to adjust an operating program of the control unit 26a such that the control unit 26a controls the switching element 24a in response to data obtained via the control inputs 66a. The control unit 26a is provided to set and / or regulate a switching frequency of the switching element 24a as a function of measured values of the sensor elements 52a, 53a of the feed module 13a.

- -

reference numeral

10 inverter unit

1 1 inverter

12 inverters

13 feed module

14 consumer

16 rectifiers

18 DC intermediate circuit

20 brake disc unit

22 rectifier element

24 switching element

26 control unit

27 software module

30 feed-in circuit

31 input interface

32 photovoltaic source

33 buffer capacity

34 inductance

40 power source

41 phase

42 phase

43 phase

50 sensor unit

51 sensor element

52 sensor element

53 sensor element

60 output interface

62 extension interface

64 sensor interface

66 control inputs

Claims

claims

Inverter unit with at least one inverter (12; 12a) for supplying at least one output-side load (14; 14a) with DC voltage applied to the input side, with at least one brake chopper unit (20; 20a) connected on the input side between at least two poles of the inverter (12; 12a) with at least one feed circuit (30; 30a) arranged to receive energy from a photovoltaic source (32; 32a)

Inverter (12; 12a) on the input side, and with at least one control unit (26; 26a) for controlling at least the feed circuit (30; 30a), characterized by a rectifier (16; 16a) which is provided to at least one phase (41 , 42, 43, 41a, 42a, 43a) of a network source (40; 40a) and to the inverter (12; 12a) on the input side, wherein the feed circuit (30; 30a) and the brake disc unit (20; 20a) at least partially in one piece are formed.

Inverter unit according to claim 1, characterized in that the

The control unit (26; 26a) is provided in at least one operating state, the brake chopper unit (20; 20a) and the feed circuit (30; 30a) at least one common switching element (24; 24a)

Switching element (24; 24a) for setting an operating point of the

To control the photovoltaic source (32, 32a) and in at least one other operating state, the switching element (24, 24a) to a release of a

To activate brake paths.

Converter unit according to one of the preceding claims, characterized in that the feed circuit (30; 30a) has at least one buffer capacitor (33; 33a).

4. converter unit according to at least claim 2 and 3, characterized in that the feed circuit (30; 30a) at least one inductance (34; 34a) which is arranged between the switching element (24; 24a) and the buffer capacitor (33; 33a) ,

5. Converter unit according to one of the preceding claims, characterized

characterized in that the brake chopper unit is connected on the output side between two poles of the rectifier.

6. Converter unit according to one of the preceding claims, characterized by a sensor unit (50; 50a) which is provided to measure at least one input-side voltage of the inverter (12; 12a).

7. converter unit according to claim 6, characterized in that the

Control unit (26; 26a) is provided for adapting at least one characteristic of the feed circuit (30; 30a) to at least one voltage measured by the sensor unit (50; 50a).

8. converter unit according to claim 7, characterized in that the

A control unit (26, 26a) is provided for addressing the feed circuit (30, 30a) in such a way that it generates a compensation signal, so that a voltage present on the input side of the inverter (12, 12a) is at least substantially constant.

9. Converter unit according to claim 8, characterized in that at least a part of the compensation signal has a frequency which corresponds to a multiple of the frequency of the phase (41, 42, 43, 41 a, 42 a, 43 a) of the network source (40; 40 a).

10. A method for operating a converter unit (10, 10a) according to one of

previous claims. System with a feed module (13a) and with a software module (27a) z Reconfiguration of an existing converter (1 1) to an inverter unit (10a) according to one of Claims 1 to 9.