KR20140076502A - Parallel connection of a number of half-bridges in h-bridges circuit modules - Google Patents

Abstract

The present invention relates to a circuit device (100) for supplying a current to a unit (200) of a vehicle. The circuit device comprises more than two half-bridges (111, 112; 121, 122) having two transistors, which are connected in parallel and the respective half-bridges (111, 112; 121, 122) are integrated into H-bridge circuit modules (110, 120). The H-bridge circuit modules include computing units (113, 123) which are integrated to be configured to enable or disable an active freewheel in accordance with an enable signal for the integrated half-bridges (111, 112, 121, 122).

Description

PARALLEL CONNECTION OF A NUMBER OF HALF-BRIDGES IN H-BRIDGES CIRCUIT MODULES IN H-

The present invention relates to circuit devices as well as methods for operating such circuit devices.

In automobiles, H-bridge transistor circuits are used for various purposes. To this end, powertrain (e.g., throttle control, exhaust gas recirculation system, variable valve control, turbocharger with variable geometry, etc.), due to relatively harsh environmental conditions (heat, temperature fluctuations, Monolithic integrated circuits (hereinafter referred to as H-bridge IC, H-bridge circuit module, or H-bridge) are used for driving DC motors in the region of the monolithic integrated circuits In addition to a number of half-bridges with circuit transistors, they also include internal control and monitoring functions, particularly internal current limiting and automatic active freewheeling.

The internal current limit causes the current provided by the half-bridge of the H-bridge to be limited to a specific value automatically (usually via internal PWM drive of the high-side transistor) for the connected component. In the active freewheel, in the passive phase (high-side transistor off), the internal freewheel diode is bridged through the switch-on of the low-side transistor. This reduces loss power. The H-bridge IC includes an internal computing unit, which may also include an interface, e.g., a bus interface (e.g., SPI bus), to provide the functionality. Through the interface, the configuration and operation of the H-bridge IC can be performed and the data can be read.

However, the "intelligent" configuration of the H-bridge IC causes difficulties because, unexpectedly, for example, in the overcurrent condition, all the half bridges are in a synchronous manner (i.e., Bridge ICs can not be connected in parallel (input and output stages in parallel) because the lateral currents can occur between the individual half-bridges, if not in the H-bridge IC.

However, under certain circumstances, for example at high current and / or high temperature conditions, it is desirable to operate two or more half-bridges of this type in parallel. In the case of automobiles, very high temperatures occur here and there. The higher the ambient temperature, the more half the bridge can provide lower power for the connected unit. Further, since the loss power that can be switched in the half bridge is limited by the monolithic configuration, when the electric demand of the connected unit is high, or when the H-bridge IC is used in a high ambient temperature condition, Are connected in parallel.

According to the present invention, a method for operating the circuit device as well as a circuit device having the features of the independent claims is proposed. Preferred embodiments are subject of the dependent claims and the following description.

The present invention is based on the fact that the parallel connection of two half bridges of an H-bridge IC is substantially in the overcurrent situation and not all half bridges are in a current limited state in synchronous manner, Utilizes the knowledge that it causes an unintended transverse current because it is switched on in the current limited state and thus forms a short circuit with the high-side transistor of the parallel half-bridge with no current limit. Therefore, parallel connection is possible through the inhibition of the active freewheel.

The present invention describes the possibility of operating two or more half bridges of intelligent H-bridge ICs in parallel in a vehicle. In this case, however, the control and monitoring functions provided to the H-bridge ICs are maintained.

The loss power generated within the H-bridges connected in parallel remains very low.

Within the scope of the present invention, H-bridge ICs that have the potential to selectively disable an active freewheel are proposed and utilized. Thereby, parallel operation of two or more half-bridges is possible even in the internal current limit state. Deactivation may be performed through a corresponding configuration of the internal computing unit of the H-bridge IC, for example, through writing of the configuration register via the SPI bus.

The present invention leads to lower (average) electronics temperature and improved efficiency. The possible temperature rise for the power peak in the transient state is also increased. (Average) system dynamic behavior is improved, and the application becomes more robust under high ambient temperature conditions. Through the increased power peak, connected units, such as throttle valves, can likewise be operated with increased dynamic behavior. This again has a positive effect on the overall system dynamic behavior.

Typical H-bridge ICs include two or more half bridges with respective central tap terminals, and the unit to be powered may be between two center tap terminals, or between one center tap terminal and ground . Now, in a parallel connection of half bridges, one or more half bridges are connected in parallel to one half bridge. Preferably, the unit for supplying electricity may be connected between two H-bridge ICs each of which has two or more half bridges connected in parallel.

Preferably, the active half-bridge active frywheel is deactivated if one or more parallel-connected second half bridges are in the current limited state.

Preferably, the active freewheel of all parallel-connected half bridges is activated or deactivated depending on the current to be supplied to the connected unit. This reduces the lost power caused by the deactivated active freewheel.

Preferably, the active freewheel can be activated and deactivated externally, for which a corresponding input is preferably provided to one or more H-bridge ICs. The inputs can be isolated or realized in the range of bus interfaces (eg SPI). Activation / deactivation may be accomplished, for example, by setting / deleting the internal configuration register. Then, the activation and deactivation of the active freewheel is preferably performed through an upper unit, preferably a microcomputer or a control device.

According to one preferred embodiment, in one operating mode, especially when the power output required for a connected unit is low ("economy mode"), all parallel connected half bridges can be completely blocked except for one half bridge , So that the low power output is performed by the one half bridge alone and accordingly in the optimum condition. In the case where the required power output is higher (power mode), in another operating mode, additional half-bridges including the inactive active freewheel in this case are activated in parallel. The appropriate switching value to threshold value between the two operating modes is determined depending on the application or unit. The switching value to the threshold value can be calculated in advance, for example, or can be measured in accordance with the generated loss power. The conversion value is preferably stored in the upper unit.

Preferably, the half-bridges can be activated and deactivated externally, and corresponding inputs are provided to one or more H-bridge ICs for the purpose. The inputs can be isolated or realized in the range of bus interfaces (eg SPI). Activation / deactivation may be accomplished, for example, by setting / deleting the internal configuration register.

A control unit of a computing unit such as an automobile according to the present invention is configured to execute the method according to the present invention in terms of program technology.

It is also desirable that the method be supplemented in the form of software, especially if the control device being executed is still used for other tasks and is provided anyway, especially since this is less costly. Suitable data carriers for providing computer programs are in particular diskettes, hard disks, flash memory, EEPROM, CD-ROM, DVD and the like. It is also possible to download programs via a computer network (Internet, intranet, etc.).

Other advantages and embodiments of the invention are set forth in the specification and the accompanying drawings.

Naturally, the above-mentioned features and the features to be described below can be used not only in the respective combinations mentioned but also in different combinations or individually, without departing from the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS The invention is schematically illustrated in the drawings using the embodiments and described in detail below with reference to the drawings.

1 is a preferred embodiment of a circuit arrangement according to the present invention for current supply of a unit.
2 is a graph showing the losses in the free wheel diodes of the transistors in operation of the unit.

In Figure 1, a preferred embodiment of a circuit arrangement 100 according to the present invention for the supply of current to the unit 200 is shown in schematic form. The unit 200 is here formed as an electric drive device (a DC motor M including a gear device) of an electric throttle device of an automobile. Circuit device 100 is also a component of an electric throttle device. The electric throttle device regulates air supply in an intake tract in the case of a gasoline engine. The electric throttle device includes a throttle valve having an electric drive device and an angle sensor.

The engine control device 10 calculates the required opening of the throttle valve, particularly from the accelerator pedal position. The DC motor regulates the throttle valve shaft through the gear unit and regulates the air flow accordingly. The throttle device uses the fine adjustment of the air to control the torque output from the engine and accordingly the output.

The circuit arrangement 100 includes two identical H-bridge circuit modules or ICs 110, 120, each with two half-bridges 111, 112 or 121, 122. In addition, each H-bridge IC 110, 120 also includes computing units 113, 123 configured to drive the transistors of the half bridges. The computing unit drives the transistors of the half bridges according to the signals applied to the driving terminals 114, 114 ', 115, 115', 116, 116 'or 124, 124', 125, 125 ', 126, 126' do. Each H-bridge IC 110, 120 includes a terminal (labeled with an "unlabeled reference mark" and a reference mark) for each half bridge, ie, in this example, always has two terminals . A freewheel diode is connected in parallel to each transistor. These freewheeling diodes may be intrinsic freewheel diodes (for example in the case of MOS transistors) or discrete elements (e.g. in the case of IGBTs).

Terminals 114, 114 'or 124, 124' are, for example, driving inputs for presetting the switching time and terminals 115, 115 'or 125, 125' Terminals 116, 116 'or 126, 126' may be freewheel inputs for deactivating the active freewheel in the H-bridge IC 110 or 120. The terminals are connected to an engine control device 10 configured to suitably drive circuit devices within the scope of the present invention.

Further, each H-bridge IC 110, 120 has output terminals 119, 119 'or 129, 129' as a center tap terminal between two transistors to which the units to be supplied with electricity are connected for each half bridge .

In the case of the illustrated circuit arrangement, two half-bridges 111 and 112 or 121 and 122, respectively, are connected in parallel so that their drive and output terminals are connected in parallel. Accordingly, the electric throttle device 200 is connected between the output terminals 119 and 119 'on one side and between the output terminals 129 and 129' on the other side.

Each H-bridge IC 110, 120 also includes supply terminals 117, 118 or 127, 128 for current supply coupled to the vehicle's electrical supply system.

The engine control device 10 is configured to drive the circuit device 100. [ According to one preferred embodiment, the parallel-connected half bridges 112 and 122 (e.g., by setting the drive time to zero) when the required power output for the electric throttle device 200 is low (Where not all of the driving terminals are connected in parallel so that the individual half-bridges may not be activated), so that the low power output is performed only through the half-bridges 111 and 121. When the required power output is greater (power mode), the half bridges 112 and 122 are activated in parallel and the active freewheel of the half bridges is deactivated. The power threshold between the economy mode and the power mode may be determined depending on the application. For example, in FIG. 2, the losses in the free wheel diodes of the transistors are mapped according to the PWM drive signal in the operation of the electric throttle device according to the example. PWM = 100% means continuous ON (ON) of the half-bridge high-side transistor.

The graph 301 shows the loss power for two parallel-connected half bridges on both sides of the DC motor M of the electric throttle apparatus, and the graph 302 shows only one half of each half of the DC motor M of the electric throttle device It is the loss power for the bridge. Here, it can be seen that the two graphs intersect at 303. If the PWM is less than 303, then the lost power 302 is smaller (i.e., preferably only one half-bridge is in operation here - "economy mode") and the lost power 301 is smaller for PWMs above 303 In other words, here both half-bridges are preferably operated in parallel - "power mode").

Claims (12)

A circuit arrangement (100) for supplying current to an in-vehicle unit (200) comprising two or more parallel-connected half-bridges (111, 112; 121, 122) each having two transistors, Each of the bridges 111, 112 (121, 122) is integrated in an H-bridge circuit module 110, 120, and the H-bridge circuit module includes an active freewheel 111, 112, And an integrated computing unit (113, 123) configured to activate or deactivate, in response to an activation signal. The circuit arrangement (100) of claim 1, wherein the integrated computing unit (113, 123) is configured to limit current through an integrated half bridge (111, 112, 121, 122). The apparatus of claim 1, wherein the unit (200) comprises two supply terminals, one of the supply terminals being connected to a center tap terminal of the two or more parallel-connected half bridges (111, 112; 121, 122) (119, 119 '; 129, 129'). The circuit arrangement (100) of claim 3, wherein the circuit arrangement (100) is a circuit arrangement (100) having two or more additional parallel connected half-bridges (111, 112; 121, 122) each having two transistors, Each of the additional half-bridges 111, 112 (121, 122) is integrated in an H-bridge circuit module 110, 120 and the other supply terminal of the supply terminals is connected to the two or more additional parallel- 119 '(129, 129') of the circuit board (112, 121, 122). The H-bridge circuit module (110, 120) according to any one of claims 1 to 4, further comprising a terminal (116, 116 '; 126, 126 ). ≪ / RTI > A circuit arrangement (100) according to any one of the preceding claims, wherein the unit (200) is a direct current unit. A method of operating a circuit arrangement (100) according to any one of the preceding claims, characterized in that in a first operating mode, two or more parallel-connected half bridges (111, 112; 121, 122) are used for supplying electricity to the unit Wherein an active freewheel for two or more half bridges (111, 112; 121, 122) is deactivated. 8. The method of claim 7, wherein in a second mode of operation, only one half bridge of the two or more parallel-connected half-bridges (111, 112; 121, 122) Lt; / RTI > 9. The method of claim 8, wherein the active freewheel for one of the at least two half bridges (111, 112; 121, 122) is not deactivated. The method according to claim 7 or 8, wherein the first and second modes of operation are preset according to the loss power in the two or more parallel-connected half-bridges (111, 112; 121, 122) . A computing unit (10) configured to perform a method of operation of a circuit arrangement according to any one of claims 7 to 9. 9. A computer readable medium having stored thereon a computer program comprising program code means for causing a computing unit to execute a method of operation of a circuit arrangement according to any one of claims 7 to 9 when executed on a computing unit.

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