CROSS-REFERENCES TO RELATED APPLICATIONS

This application is the U.S. National Stage of International Application Na. PCT/EP 2018/074714, filed Sep. 13, 2018, which designated the United States and has been published as International Publication No. WO 20191063303 A1 and which claims the priority of European Patent Application, Ser. No. 17194124.8, filed Sep. 29, 2017, pursuant to 35 U.S.C. 119(a)-(d).

BACKGROUND OF THE INVENTION

The Invention relates to a modular converter, having a connection assembly, a control assembly, a supply assembly, a rear wall assembly and a load assembly, as well as a modular converter system with the modular converter, a rear wall bus and a converter expansion module.

Electrical converters which today usually have power semiconductor switches or power modules with silicon-based power semiconductor switches arranged in bridge circuits (e.g. Si or SIC), usually require a solid metallic heat sink for heat dissipation with regard to operational heat losses. This is particularly the case when the conventional power semiconductor switches are to be operated with high reverse voltages, for example, greater than 400V, at high clock frequencies, for example, greater than 40 kHz, and with switching currents, for example, greater than 7A.

The essential structural components from which such electrical converters, in particular frequency converters with a DC link, are formed today, relate only to a few basic converter components, such as the power component, consisting of the power module for the direct and alternating direction, the solid metallic heat sink for heat dissipation of the power semiconductor switches of the power module and the control unit for controlling the inverter or the rectifier (for example, in the case of self-commutated rectifiers). These basic converter components essentially form the core, which can be changed only in a few degrees of freedom, of the electrical converter today, which, in contrast, remains largely unchanged in terms of its structural degrees of freedom over many converter types and generations.

For example, the power module for this purpose is, on the one hand, usually directly connected to the solid metallic heat sink and, on the other hand, as far as possible directly contacts the power circuit board which, inter alia, contains the control electronics for the power semi-conductor switch.

In today's converter solutions, the solid metallic heat sink also generally assumes the function of a converter housing, either completely or as part of the converter housing, which additionally restricts flexibility in design adaptations or changes with regard to the creation of further functionality of these electrical converters due to the extensive changes which are then to be carried out, in particular with regard to their converter components.

Currently, encapsulated power modules are used for most power classes so that in terms of design, i.e. from the point of view of the space requirement and the heat balance, but also electrically, i.e. from the point of view of the inductive and ohmic connection, as central converter components, these power modules result in high development costs for each device size and a considerable outlay in production.

A problem for users is therefore that only limited possibilities exist for adapting the converter products to specific customer requirements. Thus, in particular for drive converters, there are various fields of application and thus also different electrotechnical requirements for these electrical converters, such as, for example, with regard to their overload capability, electromagnetic compatibility (EMC) and specific network connection requirements.

Nevertheless, in order to meet as many of these requirements as possible, the converter types currently offered are designed in such a way that they often include a multiplicity of functions. In this way, they are usually over-dimensioned and cost-intensive, which means that customers must acquire technical functions which are not required. Apart from this, the size of the construction space, combined with a compact, flexible structure, is increasingly decisive for the suitability of such electrical converters when used in innovative plant and mechanical engineering technologies.

However, problems arise here, for example, if the control unit, as is customary, has been designed to regulate the inverter or rectifier for all performance classes. In a further development, in the case of adaptations or changes, a multiplicity of technical/technological functions of the converter components of the electrical converter must often be considered and revised or even completely redeveloped.

In this connection, parallel switching of power modules for example can be achieved only through a high outlay in changing the control of the inverter or rectifier, in particular in the layout of the control unit.

A parallel operation of individual converters is for example, scarcely possible nowadays without external inductances, which could lead to a demand for integration of such inductances into current electrical converters by users. For the user, however, this option is again not of great interest due to the high development and implementation costs that have to be paid for such labor-intensive design changes via the converter products, the time cycle until the changed converter product is available also being considered to be rather lengthy.

The object of the invention is therefore to provide electrical converter and converter systems which can be combined in modular form and which meet technical/functional user requirements by means of flexibly combinable electronic assemblies or converter components and at the same time enable a space-saving and more compact design of the electrical converter, including in combination with converter systems, compared to the state of the art.

SUMMARY OF THE INVENTION

According to one aspect of the invention, the object is achieved by a modular converter having a connection assembly, a control assembly, a supply assembly, a rear wall assembly and a load assembly, wherein

an input and an output signal and an input and an output alternating voltage can be distributed by means of the connection assembly,

first control signals for an inverter can be generated by a control unit of the control, assembly,

the input alternating voltage of a primary network can be converted into an intermediate circuit direct voltage by means of a rectifier of the supply assembly;

the intermediate circuit direct voltage and the first control signals for the inverter can be distributed by means of a DC link and a control signal circuit of the rear wall assembly,

the intermediate circuit direct voltage can be converted into the output alternating voltage for a load or secondary network by means of the inverter of the load assembly,

inverter has switches which are made of Gaff or InGaN and which can be operated with a blocked voltage of at least 400V and with a clock frequency of at least 40 kHz, and

the connection assembly and the rear wall assembly are each electrically connected to the control assembly, the supply assembly and the load assembly (6) by means of releasable mechanical connection.

The invention is based, inter alia, on the finding that, with the introduction of power semiconductor switches having a high bandwidth made of GaN or InGaN, which are operated in particular with high blocking voltages (>400V) and high clock frequencies (>40 kHz) in the case of switching currents greater than 7A, it is possible to dispense with solid metallic heat sinks used hitherto, which until now have often been completely or at least partially integrated into the housing chassis and/or into the housing cover of the electrical converter, on account of new cooling concepts or to substantially reduce the heat sinks used at least with respect to their space and material requirements.

This in turn opens up new options for the flexible use of technical/technological, i.e. functionally encapsulated electronic assemblies in modular converters or in converter systems with modular converters. Across performance class-defined converter limits, the electronic assemblies for the modular converter can be scaled with less effort and thus be used more cost-effectively.

A more compact arrangement by means of new construction concepts of such functionally designed electronic assemblies can also result in new possibilities for the use of these modular converters in previous as well as new fields of application.

A modular converter is proposed for achieving the object, which comprises a connection assembly, a control assembly, a supply assembly, a rear wall assembly and a load assembly, wherein an input signal and an output signal and an input and an output alternating voltage can be distributed by means of the connecting structure, wherein first control signals for an inverter can be generated by means of a control unit of the control assembly, wherein the input alternating voltage of a primary network can be converted into an intermediate circuit direct voltage by means of a rectifier of the supply assembly, wherein the intermediate circuit direct voltage and the first control signals for the inverter can be distributed by means of a DC link and a control signal circuit of the rear wall assembly, wherein the intermediate circuit direct voltage can be converted into the output alternating voltage for a load or a secondary network by means of the inverter of the load assembly, wherein the inverter has power semiconductor switches made of GaN or InGaN, which can be operated with a blocking voltage of at least 400V and at a clock frequency of at least 40 kHz, and wherein the connection assembly and the rear wall assembly are each electrically connected to the control assembly, the supply assembly and the load assembly by means of releasable mechanical connections.

When using power semiconductor switches made of GaN or InGaN, which lead to significantly less heat loss at high blocking voltages and clock frequencies in comparison with silicon-based power semiconductor switches, it is possible to dispense with a solid metallic heat sink—as the central converter component of electrical converters previously determining the mechanical structure and requiring considerable installation space—through new cooling concepts.

It has been recognized in an advantageous manner that more degrees of freedom are now possible for restructuring a technically/technologically or request-related functional encapsulation of assemblies.

By means of the functional components of the modular converter which are encapsulated in their functional performance, technical/technological tasks which can be limited in this way and electronic components required for this purpose can be scaled within the modular converter to the requirements of users, can be developed with little effort and can be advantageously replaced in a cost-effective manner with a mechanical design of the modular converter which can now be realized in compact form.

The proposed assemblies of the modular converter thus form the basis for a modular design of electrical converters. Each of the assemblies can be developed as required, in its own right, or in conjunction with the modular converter.

This relates not only to the adaptation of the technical/technological functionality of the assemblies, but also to the optimization/generation of fields of application of the modular converter (e.g. the operation of multi-axis drives or supply to different electrical networks), the installation space optimization of the modular converter, the optimization of the transmission of signals and electrical power, the optimization of material requirements with regard to the electronic components and the optimization of the low-cost and cost-effective replaceability of the assemblies for maintenance or upgrade possibilities.

Advantageous embodiments of the modular converter are indicated in the dependent claims.

In a first advantageous embodiment of the modular converter according to the invention, the rectifier has power semiconductor switches made of GaN or InGaN which can be operated with a blocking voltage of at least 400V and with a clock frequency of at least 40 kHz.

In addition to the externally controlled rectifiers, a self-commutated rectifier can also be operated here by means of the power semiconductor switches used, which advantageously increases the quality of the intermediate circuit direct voltage which can be generated on the DC link.

In a further advantageous embodiment of the modular converter according to the invention, the second control signals for the rectifier can be generated by means of the control unit of the control assembly and the second control signals for the rectifier can be distributed by means of the control signal circuit of the rear wall module.

In a further advantageous embodiment of the modular converter according to the invention, the modular converter has a capacitor assembly with an intermediate circuit capacitor and/or with a commutation capacitor, wherein the capacitor assembly is electrically connected at least to the rear wall assembly by means of releasable mechanical connections.

By means of the independently available and scalable capacitor assembly, it is possible to provide different capacitors in terms of their type and performance variable for the specific application requirements of the modular converter in an advantageous manner in the form of low-cost original equipment or component adaptation. For example, there are applications in which, in addition to the intermediate circuit capacitor arranged directly on the DC link on the rear wall assembly, a commutation capacitor for fast commutation processes by means of the capacitor assembly is arranged in the modular converter.

In a further advantageous embodiment of the modular converter according to the invention, the modular converter has an EMC assembly with an LC filter circuit, wherein the EMC assembly is electrically connected at least to the connection assembly by means of one of the releasable mechanical connections.

Such an EMC assembly can be arranged electrically both on the AC voltage side in front of the supply assembly, on the DC voltage side on the DC link of the rear wall assembly between the supply assembly and the load assembly, or alternatively on the AC voltage side on the load assembly in an advantageous manner.

In a further advantageous embodiment of the modular converter according to the invention, the modular converter has a further supply assembly with a further rectifier, wherein the further supply assembly is electrically connected to the first connection assembly and the first rear wall assembly by means of releasable mechanical connections.

By means of this further supply assembly, the modular converter can, for example, advantageously regulate its supply power on the electrical input side (the supply side) of the modular converter by switching the further rectifier on and off. If the further rectifier is, for example, a self-commutated rectifier, a high scalability of the regulation of the supply power can be generated.

In a further advantageous embodiment of the modular converter according to the invention, the modular converter has a further load assembly with a further inverter, wherein the further load assembly is electrically connected to the connection assembly and the rear wall assembly by means of releasable mechanical connections.

By means of this further load assembly, the modular converter can, for example, advantageously regulate its output power on the electrical output side (the load side) of the modular converter by switching the further inverter on and off.

In a further advantageous embodiment of the modular converter according to the invention, the load or the secondary network can be operated jointly by means of the inverter of the load assembly and the further inverter of the further load assembly.

In a further advantageous embodiment of the modular converter according to the invention, the load or the secondary network can be operated by means of the inverter of the load assembly and a further load or a further secondary network can be operated by means of the further inverter of the further load assembly.

In a further advantageous embodiment of the modular converter according to the invention, the releasable mechanical connections are designed as screwless plug connections.

This advantageous embodiment of the modular converter according to the invention makes it possible to further advantageously reduce the installation space for the mechanical connections of the assemblies to one other. This also enables closer interleaving of the assemblies.

In a further advantageous embodiment of the modular converter according to the invention, the power semiconductor switches can be operated with a switching current of at least 7A.

According to another aspect of the invention, the object is achieved by, a modular converter system, which comprises a modular converter according to the invention, a rear wall bus and a converter expansion module having a module connection assembly, a module coupling assembly, a module rear wall assembly and a module load assembly, wherein module input and output signals and a module output alternating voltage can be distributed by means of the module connection assembly, wherein fourth control signals, which can be generated in the control unit of the control assembly of the modular converter or in a module control unit of the module coupling assembly, can be distributed for a module inverter by means of the module coupling assembly, wherein the module intermediate circuit direct voltage and the fourth control signals for the module inverter can be distributed by means of a module DC link and a module control signal circuit of the module rear wall assembly, wherein the module intermediate circuit direct voltage can be converted into the module output alternating voltage for a module load or a module secondary network by means of the module inverter of the module load assembly, wherein power semiconductor switches of the module inverter are made of GaN or InGaN and can be operated with a blocking voltage of at least 400V and with a clock frequency of at least 40 kHz and wherein the module connection assembly and the module rear wall assembly are each electrically connected to the module coupling assembly and the module load assembly by means of releasable mechanical module connections.

The modular converter system enables the assemblies of the modular converter to be expanded as required by the module assemblies, which are arranged in the converter expansion module. In this case, the spatial arrangement of the modular converter and the converter expansion module can be both centralized and decentralized in design, only requiring an interpretation of the rear wall bus with regard to its rear wall bus direct voltage circuit and its rear wall bus control signal circuit.

In a first advantageous embodiment of the modular converter system, the intermediate circuit direct voltage of the DC link of the modular converter can be distributed to the module DC link of the converter expansion module as a module intermediate circuit direct voltage for the module inverter by means of the rear wall bus via its rear wall bus DC circuit and the fourth control signals can be distributed by the control signal circuit of the modular converter to the module control signal circuit of the converter expansion module for the module inverter by means of the rear wall bus via its rear wall bus control signal circuit.

Accordingly, the rear wall bus advantageously transmits not only the fourth control signals of the control signal circuit of the modular converter to the module inverter of the converter expansion module, but also provides the intermediate circuit direct voltage of the DC link of the modular converter to the module inverter. Accordingly, in addition to the control signals, the power for the module inverter of the converter expansion module is also supplied by the modular converter which the rectifier of the supply assembly of the modular converter generates during operation.

In a further advantageous embodiment of the modular converter system, the converter expansion module has a further module load assembly with a further module inverter, wherein the module connection assembly and the module rear wall assembly are electrically connected to the further module load assembly by means of releasable mechanical module connections.

In a further advantageous embodiment of the modular converter system, the rear wall bus is electrically connected to the electrical converter and the converter expansion module by means of releasable mechanical rear wall bus connections and the releasable mechanical module connections and the releasable mechanical rear wall bus connections are designed as screwless plug connections.

This advantageous embodiment of the modular converter system according to the invention makes it possible to advantageously reduce the installation space for the mechanical connections of the modular converter to the converter expansion module. This also enables closer interleaving of the components of the modular converter system.

