WO2017016828A1

WO2017016828A1 - Multiphase inverter

Info

Publication number: WO2017016828A1
Application number: PCT/EP2016/065920
Authority: WO
Inventors: Taleb Janbein
Original assignee: Robert Bosch Gmbh
Priority date: 2015-07-28
Filing date: 2016-07-06
Publication date: 2017-02-02
Also published as: CN107852086B; CN107852086A; DE102015214276A1; EP3329582A1

Abstract

The invention relates to a multiphase inverter (10) for controlling a multiphase consumer (50), comprising multiple input terminals (25, 26, 27, 28) for connecting at least one first battery (21) and one second battery (22), as well as multiple phase outputs (51, 52, 53) for connecting the consumer (50), wherein a bridge circuit (31, 32, 33) with controllable switches (S1, S2, S3, S4, S5; S6, S7, S8, S9, S10; S11, S12, S13, S14, S15) is assigned to each phase output (51, 52, 53), via which switches the phase output (51, 52, 53) can be connected to different input terminals (25, 26, 27, 28). In addition, each bridge circuit (31, 32, 33) has an input switch (S1; S6; S11) connected to a first input terminal (25) and to the phase output (51, 52, 53), multiple node switches (S2, S3, S5; S7, S8, S10; S12, S13, S15) connected to the remaining input terminals (26, 27, 28) and to a node point (41, 42, 43), and an output switch (S4; S9; S14) connected to the node point (41, 42, 43) and to the phase output (51, 52, 53).

Description

Multi-phase inverter

The invention relates to a polyphase inverter for controlling a multiphase consumer, which has a plurality of input terminals for

Connection of at least a first battery and a second battery and a plurality of phase outputs for connection of the consumer comprises.

State of the art

For driving a multiphase consumer, for example a three-phase electric motor, it is known to use inverters. Such inverters are also referred to as inverters. The inverter makes it possible to feed the load from a DC voltage source, such as a battery.

Inverters are used in particular in electric vehicles for driving a three-phase electric motor. Inverters

for example, also used to generate electricity in one

Photovoltaic system is generated to feed into an existing supply network.

There are known inverters, to which several, for example two, batteries can be connected. With appropriate control of the

Inverter, the consumer can be fed either from the first battery, from the second battery or from a series connection of both batteries. As a result, the consumer can be supplied with different voltages. Such inverters are also referred to as multilevel inverters.

A generic inverter is known from DE 10 2012 012 048 AI. The inverter comprises several input terminals to which two capacitors are connected, and three phase outputs for connecting a three-phase machine. Each of the three phase outputs is assigned a bridge circuit with controllable switches, by which the respective phase output can be connected to the various input terminals.

DE 10 2012 212 556 AI discloses an electrical circuit with

controllable switches and with two phase outputs. By appropriate control of the switch three different voltages between the phase outputs are adjustable.

DE 10 2013 215 572 A1 discloses an energy storage device with two phase outputs. In this case, the energy storage device has a plurality of multi-voltage stage converters, which are also referred to as multilevel converters.

In DE 10 2011 056 135 Al power generation plant is disclosed, which has a generator and an inverter. The inverter is designed as a multi-level inverter.

Disclosure of the invention

It is proposed a polyphase inverter for driving a multi-phase load. The inverter includes several

Input terminals for connecting at least a first battery and a second battery and a plurality of phase outputs for connecting the consumer. Each phase output is assigned a bridge circuit with controllable switches, by means of which the phase output can be connected to various input terminals.

According to the invention, each bridge circuit has an input switch, a plurality of node switches and an output switch. The input switch of each bridge circuit is connected to a first input terminal and to the phase output. The node switches of each bridge circuit are connected to one of the remaining input terminals and to a node. The output switch of each bridge circuit is connected to the node and to the phase output. So that the phase output can be connected optionally to the first input terminal as well as to the node.

Preferably, three phase outputs are provided for connecting a three-phase load, for example a three-phase motor.

The switches comprise at least one transistor, a diode and a drive unit. The diode is connected to the transistor in such a way that a current can flow in a predetermined direction, even if the transistor is turned off. The transistor is preferably a

Bipolartransistor or to an insulated gate bipolar transistor (IGBT).

Preferably, the first input terminal and a second

Input terminal for connection of the first battery provided, and a third input terminal and a fourth input terminal are provided for connection of the second battery.

Advantageously, the inverter is designed such that when open

Switching the first input terminal and the second input terminal are electrically isolated from the third input terminal and the fourth input terminal.

Among other things, each bridge circuit has a primary node switch connected to the second input terminal and to the node. The primary node switch is thus connected to the first battery as well as the input switch.

According to an advantageous embodiment of the invention, the

Primary node switch designed as anti-parallel switch and each comprise two transistors, two diodes and a drive unit. The diodes are connected to the transistors in such a way that a current can not flow in any direction when the transistors block. Advantageously, the inverter is designed such that, when both batteries are connected, with the switches open, the first battery is galvanically isolated from the second battery.

An inverter according to the invention advantageously finds use in an electric vehicle (EV), in a hybrid vehicle (HEV), in a plug-in hybrid vehicle (PHEV), in particular for driving a three-phase electric motor, or in a photovoltaic system. The inventive

Inverter is basically used everywhere, if two batteries

are to be connected.

Advantages of the invention

With appropriate control of the inverter according to the invention, the connected consumer can be fed either from the first battery, from the second battery or from a series connection of both batteries. As a result, the connected consumer can be supplied with different high voltages. Thus, the inventive

Inverter the functionality of a multilevel inverter.

In addition, the connected consumer with appropriate

Control of the inverter according to the invention also from a

Parallel connection of both batteries are fed. As a result, a higher current can be supplied to the connected consumer at the same voltage.

In the case of a parallel connection of both batteries for feeding the

connected load, the voltage of the first battery may be greater than the voltage of the second battery. The consumer is initially fed exclusively from the first battery, which has the higher voltage and thus the higher state of charge. Only when the first battery is discharged to the extent that the charge states of the two batteries are approximately equal, the connected load from both batteries is powered. In such a parallel connection of a first battery with a higher state of charge and a second battery with a lower state of charge, the first battery is thus initially discharged until the states of charge of both batteries are approximately equalized. Thereafter, both batteries are discharged approximately similarly. Thus, with a supply of the

Connected load from a parallel connection of both batteries automatically an adjustment of the charge states instead, which is also referred to as balancing.

Brief description of the drawings

Embodiments of the invention will be explained in more detail with reference to the drawings and the description below.

Show it:

1 shows a schematic representation of a polyphase, in particular three-phase, inverter,

Figure 2 is a schematic representation of a switch of the inverter of Figure 1 and

Figure 3 is a schematic representation of a primary node switch of

Inverter of Figure 1.

Embodiments of the invention

In the following description of the embodiments of the invention, the same or similar elements are denoted by the same reference numerals, wherein a repeated description of these elements is dispensed with in individual cases. The figures illustrate the subject matter of the invention only schematically.

Figure 1 shows a schematic representation of a multi-phase, in particular three-phase inverter 10. The inverter 10 includes a first entry terminal 25, a second entry terminal 26, a third

Entrance terminal 27 and a fourth input terminal 28.

A positive pole of a first battery 21 is connected to the first input terminal 25. A negative pole of the first battery 21 is connected to the second one

Input terminal 26 connected. A positive pole of a second battery 22 is connected to the third input terminal 27. A negative pole of the second battery 22 is connected to the fourth input terminal 28.

The first battery 21 supplies a first battery voltage U B1, which is present between the first input terminal 25 and the second input terminal 26. The second battery 22 supplies a second battery voltage U B2, which is applied between the third input terminal 27 and the fourth input terminal 28.

The inverter 10 further includes a first phase output 51, a second phase output 52 and a third phase output 53. A consumer 50 is connected to the phase outputs 51, 52, 53. The consumer 50 is in the present case designed in three phases and has a first strand 61, a second strand 62 and a third strand 63. The first strand 61 is connected to the first phase output 51, the second strand 62 is connected to the second phase output 52, and the third strand 63 is connected to the third phase output 53.

The first strand 61 of the load 50 comprises a load, which in the present case is shown as a series circuit of an inductance and an ohmic load. Similarly, the second leg 62 comprises a load, which is shown as a series circuit of an inductance and a resistive load. Also, the third strand 63 includes a load referred to as

Series circuit of an inductance and a resistive load is shown. The strands 61, 62, 63 of the consumer 50 are at one

Star point 60 merged and connected.

Between the first phase output 51 and the star point 60, a first output voltage Ul drops. Between the second phase output 52 and the Star point 60 drops a second output voltage U2. Between the third phase output 53 and the neutral point 60, a third output voltage U3 drops. The first phase output 51 is assigned a first bridge circuit 31.

The second phase output 52 is a second bridge circuit 32

assigned. The third phase output 53 is assigned a third bridge circuit 33.

The first bridge circuit 31 comprises a first input switch S1 connected to the first input terminal 25 and to the first input terminal S1

Phase output 51 is connected. The second bridge circuit 32 comprises a second input switch S6, which is connected to the first input terminal 25 and to the second phase output 52. The third

Bridge circuit 33 includes a third input switch Sil connected to the first input terminal 25 and to the third phase output 53.

The first bridge circuit 31 comprises a first primary node switch S2, which is connected to the second input terminal 26 and to a first node 41. The second bridge circuit 32 includes a second one

Primary node switch S7, which is connected to the second input terminal 26 and to a second node 42. The third bridge circuit 33 comprises a third primary node switch S12, which is connected to the second input terminal 26 and to a third node 43.

The first bridge circuit 31 comprises a first secondary node switch S3 which is connected to the third input terminal 27 and to the first node 41. The second bridge circuit 32 includes a second one

Secondary node switch S8 connected to the third input terminal 27 and to the second node 42. The third bridge circuit 33 comprises a third secondary node switch S13, which is connected to the third

Input terminal 27 and connected to the third node 43. The first bridge circuit 31 includes a first tertiary node switch S5 connected to the fourth input terminal 28 and to the first node 41. The second bridge circuit 32 includes a second one

Tertiary node switch S10 connected to the fourth input terminal 28 and to the second node 42. The third bridge circuit 33 includes a third tertiary node circuit S15 connected to the fourth input terminal 28 and to the third node 43.

The first bridge circuit 31 includes a first output switch S4 connected to the first node 41 and to the first phase output 51. The second bridge circuit 32 includes a second one

Output switch S9, which is connected to the second node 42 and the second phase output 52. The third bridge circuit 33 includes a third output switch S14 connected to the third node 43 and to the third phase output 53.

With appropriate control of said switches Sl to S15, the connected load 50 can be fed either from the first battery 21, from the second battery 22, as well as from a series circuit of the first battery 21 and second battery 22. Likewise, the consumer 50 can be powered by a parallel connection of the first battery 21 and second battery 22 with appropriate control of the switch Sl to S15. In this case, the consumer 50 is supplied with alternating output voltages U1, U2, U3, which have a phase offset to each other.

In the following tables 1 to 4 is shown in each case in which position the switch Sl to S15 which output voltage Ul, U2, U3 applied to the strands 61, 62, 63 of the load 50.

For all tables 1 to 4:

1 switch closed

empty switch open

D switch open, but current flow parallel to the switch through diode 81 S1 S2 S3 S4 S5 S6 S7 S8 S9 S10 S11 S12 S13 S14 S15 U1 U2 U3

1 1 1 1 1/3 U 1/3 U -2/3 U

1 1 1 1 1 2/3 U -1/3 U -1/3 U

1 1 1 1 1/3 U -2/3 U 1/3 U

1 1 1 1 1 -1/3 U -1/3 U 2/3 U

1 1 1 1 -2/3 U 1/3 U 1/3 U

1 1 1 1 1 -1/3 U 2/3 U -1/3 U

Table 1: the consumer 50 is fed exclusively by the first battery 21. Then: U = UB1

Table 2: the consumer 50 is fed exclusively by the second battery 22. Then: U = UB2

Table 3: the consumer 50 is powered by a series connection of the first battery 21 and the second battery 22. Then: U = UB1 + UB2

Table 4: the consumer 50 is from a parallel circuit of the first

Battery 21 and second battery 22 fed. There are several variants. If the first battery voltage UB1 is approximately equal to the second

Battery voltage UB2 is a real parallel connection. Then:

U = UB1 = UB2. As long as the first battery voltage UB1 significantly larger than the second

Battery voltage UB2, there is no current flow through the diode 81. The load 50 is fed exclusively by the first battery 21.

Then:

U = UB1

If the first battery voltage UB1 significantly smaller than the second

Battery voltage UB2, so no parallel connection of the first battery 21 and second battery 22 may take place. In this case, a control unit, not shown here prevents a corresponding control of the switch Sl to S15 of the inverter 10th

Figure 2 shows schematically the structure of an input switch Sl, S6, Sil, an output switch S4, S9, S14, a secondary node switch S3, S8, S13 and a Tertiärknotenschalters S5, S10, S15. The said switches each comprise a transistor 80, which in the present case is designed as a bipolar transistor. The transistor 80 includes a base B, an emitter E, and a collector C. The transistor 80 may also be implemented as an insulated gate bipolar transistor (IGBT) and in this case comprises a gate instead of the base B.

Between the emitter E and the collector C, a diode 81 is connected in parallel. The base B is connected to a drive unit 82. By appropriate control by means of the drive unit 82, the transistor 80 can be turned off or turned on. Accordingly, the affected switch is opened or closed.

FIG. 3 shows a primary node switch S2, S7, S12. Deviating from the switch shown in FIG. 2, the primary node switch S2, S7, S12 comprises a first transistor 80 and a second transistor 80 as well as a first diode 81 and a second diode 81. The two transistors 80 are in the present case designed as a bipolar transistor and each comprise a base B, an emitter E and a collector C. The transistors 80 may also be embodied as an insulated gate bipolar transistor (IG BT) and in this case each comprise a gate instead of the base B.

Between the emitter E and the collector C of each of the two transistors 80, one of the two diodes 81 is connected in parallel. The bases B of both transistors 80 are connected to a common drive unit 82. Both transistors 80 are driven by the common drive unit 82.

The invention is not limited to the embodiments described herein and the aspects highlighted therein. Rather, within the scope given by the claims a variety of modifications are possible, which are within the scope of expert action.

Claims

claims

A multiphase inverter (10) for driving a polyphase load (50) comprising

a plurality of input terminals (25, 26, 27, 28) for connecting at least a first battery (21) and a second battery (22) and a plurality of phase outputs (51, 52, 53) for connecting the load (50), wherein

each phase output (51, 52, 53) has a bridge circuit (31, 32, 33) with controllable switches (S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, Sil, S12, S13, S14, S15), by means of which the phase output (51, 52, 53) can be connected to different input terminals (25, 26, 27, 28),

characterized in that

each bridge circuit (31, 32, 33)

an input switch (Sl; S6; Sil) connected to a first

Input terminal (25) and connected to the phase output (51, 52, 53),

a plurality of node switches (S2, S3, S5, S7, S8, S10, S12, S13, S15) connected to the other input terminals (26, 27, 28) and to a

Node (41, 42, 43) are connected, and

an output switch (S4, S9, S14) connected to the node (41,

42, 43) and connected to the phase output (51, 52, 53).

Second inverter (10) according to claim 1, characterized in that three phase outputs (51, 52, 53) for connection of a three-phase load (50) are provided.

Inverter (10) according to one of the preceding claims, characterized in that

the switches (S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, Sil, S12, S13, S14, S15) comprise at least one transistor (80), a diode (81) and a drive unit (82 ).

Inverter (10) according to one of the preceding claims, characterized in that

the first input terminal (25) and a second input terminal (26) for connection of the first battery (21) are provided, and that a third input terminal (27) and a fourth input terminal (28) for connection of the second battery (22) are provided.

Inverter (10) according to claim 4, characterized in that when switches are open (S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, Sil, S12, S13, S14, S15)

the first input terminal (25) and the second input terminal (26) are galvanically isolated from the third input terminal (27) and from the fourth input terminal (28).

Inverter (10) according to one of claims 4 to 5, characterized in that

each bridge circuit (31, 32, 33) has a primary node switch (S2; S7; S12) connected to the second input terminal (26) and to the node (41, 42, 43).

Inverter (10) according to claim 6, characterized in that the primary node switches (S2; S7; S12) are designed as antiparallel switches and each comprise two transistors (80), two diodes (81) and a drive unit (82).

Inverter (10) according to one of the preceding claims, characterized in that

with open switches (S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, Sil, S12, S13, S14, S15), the first battery (21) is galvanically isolated from the second battery (22) ,

9. The use of the inverter (10) according to any one of the preceding claims in an electric vehicle (EV), in a hybrid vehicle (H EV), in a plug-in hybrid vehicle (PHEV) or in a photovoltaic system.