CN113364282B - Multi-path intelligent control circuit for high-voltage distribution box and control method thereof - Google Patents

Abstract

The invention provides a multi-path intelligent control circuit for a high-voltage distribution box and a control method thereof, which solve the technical problem of poor control reliability caused by substantial defects of the existing high-voltage distribution box electrical structure. The control circuit includes: the high-voltage loop is used for connecting a high-voltage power signal to the input side, forming a controlled pre-charging loop connected with the load end of the contactor in the power distribution branch circuit on the output side as required, and forming a power conversion circuit between the input side and the output side, and outputting a controlled pre-charging power signal to the gated controlled pre-charging loop; the circuit control module is used for controlling the formation of a gating signal to enable the controlled pre-charging loop, and forming a pulse width modulation wave regulating power conversion circuit to output a pre-charging power signal. The pre-charging power signal formed by using the PWM control mode has the technical advantages of flexible and adjustable pre-charging speed and voltage precision, realizes accurate switching of the power distribution branch circuit, and prolongs the service life of the main contactor. The highly integrated implementation employs a minimum of sensors to achieve complete voltage detection.

Description

A multi-channel intelligent control circuit for a high-voltage distribution box and its control method

technical field

The invention relates to the technical field of power supply control, in particular to a multi-channel intelligent control circuit for a high-voltage distribution box and a control method thereof.

Background technique

In the existing technology, electric-drive special vehicles are powered by a power unit composed of a 600VDC power battery and a diesel-generator, driven by a wheel-side drive motor, and have the characteristics of "high reliability, high safety, fast mobility, easy use, and independent controllability" Features. As the distribution equipment of high-voltage energy of the vehicle, the high-voltage distribution box provides power supply and distribution for each high-voltage electrical equipment of the vehicle, and realizes the status monitoring, remote control and information communication of the high-voltage power distribution circuit.

The electrical structure of the high-voltage distribution box in the prior art is shown in FIG. 1 . In Figure 1, the input terminal of the distribution box is connected to the power battery, and the load terminal can be connected to drive motors, power units, AC/DC, DC/DC and other equipment, and the interconnection terminal is used for cascading multiple high-voltage distribution boxes. The power distribution of the high-voltage distribution box to each branch is completed by the main contactor (such as KM1). The pre-charging branch consists of a low-power pre-charging contactor (such as KM2) and a pre-charging resistor. The power distribution process of the high-voltage distribution box to a branch circuit is as follows: first close the pre-charge contactor, at this time the pre-charge resistance is connected in series to the power distribution circuit to charge the load and raise the load voltage. After a period of time, the load voltage rises When the voltage is not much different from the DC bus voltage, turn on the main contactor of this branch, and then disconnect the pre-charging contactor of this branch, and the power distribution of this branch is completed. The electrical structure of the existing distribution box has the following problems:

It is necessary to configure a pre-charging circuit consisting of a pre-charging resistor and a pre-charging contactor for each power distribution branch. The pre-charging circuit occupies a large volume and weight of the distribution box; Fast, after the load voltage rises, the charging speed gradually decreases, resulting in a long pre-charging process; when there is no voltage sensor at the load end, the load terminal voltage cannot be detected, and whether the pre-charging is complete can only be roughly judged by the pre-charging time. The load capacitance is large, but the pre-charging time is short, and it is still easy to cause the main contactor to stick due to the incomplete pre-charging; also when there is no voltage sensor at the load end, the main contactor can only be judged by the main contactor on and off. The auxiliary contact detection of the contactor increases the volume of the main contactor and increases the cost.

Contents of the invention

In view of the above problems, the embodiments of the present invention provide a multi-channel intelligent control circuit for a high-voltage distribution box and its control method, which solves the technical problem of poor control reliability caused by substantial defects in the electrical structure of the existing high-voltage distribution box.

The multi-channel intelligent control circuit for the high-voltage distribution box of the embodiment of the present invention includes:

The high-voltage circuit is used to connect high-voltage power signals on the input side, and form a controlled pre-charging circuit connected to the load end of the contactor in the power distribution branch circuit on the output side as required, and form a power conversion circuit between the input side and the output side. Outputting a controlled pre-charge power signal to the gated controlled pre-charge circuit;

The circuit control module is used to control and form a gate signal to enable the controlled pre-charging circuit, and form a pulse width modulation wave to adjust the power conversion circuit to output the pre-charging power signal.

The multi-channel intelligent control method for the high-voltage distribution box of the embodiment of the present invention uses the above-mentioned multi-channel intelligent control circuit for the high-voltage distribution box, including:

The gate signal is controlled to enable the controlled pre-charging circuit, and a pulse width modulation wave is formed to adjust the power conversion circuit to output the pre-charging power signal.

The multi-channel intelligent control circuit and control method for the high-voltage distribution box of the embodiment of the present invention replace the auxiliary contacts of the pre-charging resistance, pre-charging contactor and main contactor by forming a power conversion circuit and a controlled pre-charging circuit, and realize The optimization of the size, space and weight of the distribution box saves the manufacturing cost. Using the PWM control method to form the pre-charging power signal has the technical advantages of flexible and adjustable pre-charging speed and voltage accuracy, which can realize the precise switching between the pre-charging link and the closing link of the main contactor, and prolong the service life of the main contactor. The high integration of multi-channel intelligent control circuits provides a circuit basis for the judgment of voltage detection, connection detection and adhesion detection with the least professional sensors, which further simplifies the control circuit of the distribution box.

Description of drawings

FIG. 1 is a schematic diagram of the architecture of a medium and high voltage distribution box in the prior art.

FIG. 2 is a schematic diagram of the structure of a multi-channel intelligent control circuit for a high-voltage distribution box according to an embodiment of the present invention.

FIG. 3 is a schematic structural diagram of a high-voltage circuit of a multi-channel intelligent control circuit for a high-voltage distribution box according to an embodiment of the present invention.

Fig. 4 is a flow chart of the pre-charging control process in the multi-channel intelligent control method deployed in the circuit control module of the multi-channel intelligent control circuit for high-voltage distribution boxes according to an embodiment of the present invention.

Fig. 5 is a schematic diagram of the signal feedback-output of the double closed-loop control strategy in the pre-charging control process in the multi-channel intelligent control method for high-voltage distribution boxes according to an embodiment of the present invention.

Fig. 6 is a flow chart of the detection process of the distribution branch circuit in the multi-channel intelligent control method for the high-voltage distribution box according to an embodiment of the present invention.

Fig. 7 is a flow chart of the power-off control process of the distribution branch in the multi-channel intelligent control method for the high-voltage distribution box according to an embodiment of the present invention.

Detailed ways

In order to make the purpose, technical solution and advantages of the present invention clearer and clearer, the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. Apparently, the described embodiments are only some of the embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

A multi-channel intelligent control circuit for a high-voltage distribution box according to an embodiment of the present invention is shown in FIG. 1 . In Fig. 1, this embodiment includes:

The high-voltage circuit is used to connect high-voltage power signals on the input side, and form a controlled pre-charging circuit connected to the load end of the contactor in the power distribution branch circuit on the output side as required, and form a power conversion circuit between the input side and the output side. To output a controlled pre-charge power signal to the gated controlled pre-charge circuit.

Those skilled in the art can understand that the high-voltage circuit is the same as other power supply circuits, there is an electrical interface connecting the input positive and input negative on the access side, and there is an electrical interface connecting the output positive and input negative on the output side. In the embodiment of the present invention, the input side is connected to the positive and negative poles of the DC bus of the high-voltage distribution box, and at least one controlled pre-charging circuit can be formed on the output side as required, and each controlled pre-charging circuit is connected to the main contact in one power distribution branch circuit. the load side of the device.

The circuit control module is used to form a strobe signal to enable the controlled pre-charging circuit, and form a pulse width modulation wave to adjust the power conversion circuit to output a pre-charging power signal.

The controlled formation of the gate signal can make the corresponding controlled pre-charging circuit communicate with the power conversion circuit to form a power supply circuit.

In an embodiment of the present invention, the circuit control module includes:

The memory is used to store the program code of the processing process in the multi-channel intelligent control method;

The processor is used to execute the program codes of the processing process in the multi-channel intelligent control method.

The processor can adopt DSP (Digital Signal Processor) digital signal processor, FPGA (Field-Programmable Gate Array) field programmable gate array, MCU (Microcontroller Unit) system board, SoC (system on a chip) system board or include I/ O's PLC (Programmable Logic Controller) minimum system.

The multi-channel intelligent control circuit for the high-voltage distribution box of the embodiment of the present invention replaces the auxiliary contacts of the pre-charging resistance, the pre-charging contactor and the main contactor by forming a power conversion circuit and a controlled pre-charging circuit, and realizes the power distribution box The optimization of size, space and weight saves manufacturing cost. Using the PWM control method to form the pre-charging power signal has the technical advantages of flexible and adjustable pre-charging speed and voltage accuracy, which can realize the precise switching of the pre-charging link and the closing link of the main contactor, and prolong the service life of the main contactor. The high integration of multi-channel intelligent control circuits provides a circuit basis for the judgment of voltage detection, connection detection and adhesion detection with the least professional sensors, which further simplifies the control circuit of the distribution box.

The structure of the high-voltage circuit of the multi-channel intelligent control circuit for the high-voltage distribution box according to an embodiment of the present invention is shown in FIG. 3 . In Figure 3, the power conversion circuit of the high-voltage circuit includes filter capacitor C, IGBT switch tube T, diode D, inductance coil L, input voltage sensor V1 and output voltage sensor V2, and the controlled pre-charging circuit includes branch selection switch tube S _n , the collector of the IGBT switch T is connected to the high voltage input positive, the emitter of the IGBT switch T is connected in series with the cathode of the diode D, the anode of the diode D is connected to the high voltage input negative, and the two ends of the filter capacitor C are respectively connected to the collector of the IGBT switch T The electrode and the emitter, the emitter of the IGBT switching tube T is connected in series with the inductance coil L and then connected to the parallel branch selection switching tube S _n , the gate of the IGBT switching tube T is connected to the corresponding control signal output pin or interface of the circuit control module, input The voltage sensor V1 is connected in parallel with the filter capacitor C, one end of the output voltage sensor V2 is connected to the anode of the diode D, and the other end of the output voltage sensor V2 is connected between the inductance coil L and the parallel branch selection switch tube S _n , each branch The selection switches S _{n (n=1, 2, 3...)} are connected in series in a controlled pre-charging circuit.

As shown in Figure 3, in one embodiment of the present invention, the branch selection switch S _n includes two insulated gate bipolar transistors (IGBTs), and the two insulated gate bipolar transistors are connected in reverse parallel, specifically Yes, the collector and emitter of one IGBT are correspondingly connected to the emitter and collector of another IGBT. As shown in FIG. 3 , in an embodiment of the present invention, the gates of the two insulated gate bipolar transistors and the IGBT switch T are respectively connected to corresponding control signal output pins or interfaces of the circuit control module.

The high-voltage circuit in the multi-channel intelligent control circuit for high-voltage distribution box of the embodiment of the present invention forms a controlled parallel controlled pre-charging circuit through the parallel branch selection switch tube _Sn , and passes through the emitter of the IGBT switch tube T and the inductance coil L forms a series transmission circuit of the power conversion circuit, and the series transmission circuit and the parallel controlled pre-charging circuit are sequentially connected.

In the high-voltage circuit of the embodiment of the present invention, the high-voltage power signal on the input side is controlled to form a pre-charging power signal, and then the corresponding pre-charging branch of each power distribution branch is formed through a series transmission circuit and a parallel controlled pre-charging circuit. The on-off enabling of the pre-charging branch is determined by selecting the branch selection switch Sn. The voltage detection on the node and input side of the series transmission circuit and the parallel controlled pre-charging circuit can be obtained by the corresponding voltage sensor The state judgment data greatly simplifies the circuit structure of the high-voltage circuit. At the same time, by using the controllable characteristics of the IGBT switch tube T and the branch selection switch tube _Sn , the flexible control of the response characteristics of the parallel pre-charge branch is well realized, which can make the high-voltage circuit adapt to the circuit load of each power distribution branch huge differences and power distribution needs. High-speed pre-charging, reliable power distribution and power-off process can be realized. Realize accurate monitoring of the contact state of the main contactor, protect the main contactor, and prolong the service life of the main contactor. The multi-channel intelligent control circuit based on the embodiment of the present invention can be applied in any similar application system requiring DC power distribution.

A multi-channel intelligent control method for a high-voltage distribution box according to an embodiment of the present invention includes:

The controlled gate signal is formed to enable the controlled pre-charging circuit, and the pulse width modulation wave is formed to adjust the power conversion circuit to output the pre-charging power signal.

The pre-charging control process in the multi-channel intelligent control method for the high-voltage distribution box according to an embodiment of the present invention is shown in FIG. 4 . In Figure 4, the pre-charge control process includes:

Turn on a branch selection switch tube _Sx according to the strobe signal to form an IGBT switch tube T-inductance coil L-determine the pre-charging current path of the load;

Control the current and voltage of the IGBT switch tube T so that the output voltage U _o is stable at the control target voltage U _o.ref ; the control target voltage U _o.ref is related to the distribution voltage required for the effective on-off of the main contactor of the distribution branch; Current and voltage control can be sequential control or synchronous control;

When the output voltage U _o ≥ the control target voltage U _o.ref , the pre-charging of the pre-charging current path is completed, the pmw control of the IGBT switch T is stopped, the circuit selection switch Sx is disabled, the pre-charging current path is disconnected, and the corresponding distribution The main contactor in the electric branch circuit is controlled to connect the power distribution branch circuit;

When the output voltage U _o ≥ control target voltage U _o.ref cannot be reached all the time, it enters the failure processing mode.

The double-closed-loop control strategy used in the current and voltage control process in the multi-channel intelligent control method for high-voltage distribution boxes in an embodiment of the present invention is shown in FIG. 5 . In Figure 5, the double closed-loop control strategy includes:

a. Set the precharge voltage error quantization process V _comp to compare the difference between the output voltage U _o and the control target voltage U _o.ref to form a voltage deviation quantization signal.

In this embodiment, the control target voltage U _o.ref is 90% of the distribution voltage UH of the distribution branch required for effective action of the main contactor contacts of the distribution branch.

b. Set the voltage closed-loop control process C _V to form the output current saturation value (iL.max), adjust the output voltage U _o according to the voltage deviation quantization signal, and form the output current desaturation according to the voltage deviation quantization signal.

Those skilled in the art can understand that the initial output value and the output change value and change range formed according to the input can be set through the corresponding phase-locked loop or PI control circuit. The output current saturation value (iL.max) is determined by characterization of the active device parameters in the precharge current path. When the output voltage _Uo reaches the control target voltage _Uo.ref , the quantized signal of the voltage deviation is the smallest. According to the correlation between the output current and the control target voltage _Uo.ref , the current output shows a desaturation trend, which makes the output current of the power conversion circuit drop.

c. Set the inductor current error calculation process I _comp , which is used to compare the difference between the output current iL and the output current saturation value to form a current deviation quantization signal.

d. Set the current closed-loop control process C _I for forming a pmw wave signal according to the quantized signal of the current deviation.

e. Set the IGBT switch control process PWM, which is used to control the IGBT switch tube T to output a pulse power signal according to the pmw wave signal to form an output current iL and an output voltage U _o .

The double-closed-loop control strategy formed by the multi-channel intelligent control method of the high-voltage power distribution box in the embodiment of the present invention makes the pre-charge output voltage rise linearly by determining the output current saturation value, and utilizes the current output oversaturation state and desaturation state in the voltage closed-loop control process Adjusting the power output of the current closed-loop control process realizes the matching of the pre-charging instantaneous power in the pre-charging current path with the load and the main contactor, ensuring the reliability of the main contactor on-off.

In practical applications, when the precharge output voltage U _o in the precharge current path reaches the control target voltage U _o . The current iL decreases dynamically accordingly, forming the pre-charging output voltage U _o to stabilize at the control target voltage U _o.ref , that is, the voltage difference between the two ends of the main contactor in the pre-charging current path is only 10 of the distribution voltage UH of the distribution branch %, so that the hidden danger of the action of the main contactor on the power distribution branch is basically eliminated. At the same time, the voltage changes of different circuit nodes in the control process of the double closed-loop control strategy can become the accurate judgment basis for the action of the actuator on the power distribution branch.

In an embodiment of the present invention, the pre-charging speed is further increased by adjusting the saturation value iL.max of the Cv output by selecting a loop circuit element with a larger current-carrying capacity. When the output current saturation value iL.max is doubled, the pre-charge time is reduced by half.

The detection process of the distribution branch circuit deployed in the circuit control module of the multi-channel intelligent control circuit for the high-voltage distribution box according to an embodiment of the present invention is shown in FIG. 6 . In Figure 6, the distribution branch detection process includes:

Set the number of detection process cycles according to the number of branch selection switch tubes S _n , to detect the voltage change of each power distribution branch;

In each detection process, the control branch selects the switching tube S _x to enable to form a corresponding pre-charging current path; at this time, the IGBT switching tube T does not output a power signal;

After the delay is determined, the voltage data of the corresponding power distribution branch is indirectly obtained by sampling the voltage of the pre-charging current path, and then the branch selection switch S _x is disabled to disconnect the corresponding pre-charging current path.

The power-off control process of the distribution branch deployed in the circuit control module of the multi-channel intelligent control circuit for the high-voltage distribution box according to an embodiment of the present invention is shown in FIG. 7 . In Figure 7, the power distribution branch power outage control process includes:

On-demand control determines that the main contactor of the power distribution branch is disconnected;

After the time delay is determined, the branch selection switch S _x corresponding to the determined power distribution branch is enabled to form a corresponding pre-charging current path; at this time, the IGBT switch T does not output a power signal;

When the output voltage U _o of the pre-charging current path drops, the branch selection switch S _x corresponding to the determined power distribution branch is disabled, and it is judged that the disconnection of the determined power distribution branch is completed;

When the output voltage U _o of the precharge current path is maintained, it enters the fault handling mode.

The above is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed in the present invention can easily think of changes or Replacement should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the protection scope of the claims.

Claims (9)

1. A multi-channel intelligent control circuit for a high-voltage distribution box, characterized in that it comprises: The high-voltage circuit is used to connect high-voltage power signals on the input side, and form a controlled pre-charging circuit connected to the load end of the contactor in the power distribution branch circuit on the output side as required, and form a power conversion circuit between the input side and the output side. Outputting a controlled pre-charge power signal to the gated controlled pre-charge circuit; The circuit control module is used to control the formation of a gating signal to enable the controlled pre-charging circuit, and form a pulse width modulation wave to adjust the power conversion circuit to output the pre-charging power signal; The power conversion circuit includes a filter capacitor C, an IGBT switch tube T, a diode D, and an inductance coil L. The controlled pre-charging circuit includes a branch selection switch tube S _n , and the collector of the IGBT switch tube T is connected to a high-voltage input Positive, the emitter of the IGBT switch T is connected in series with the cathode of the diode D, the anode of the diode D is connected to the high voltage input negative, and the two ends of the filter capacitor C are respectively connected to the collector and emitter of the IGBT switch T , the emitter of the IGBT switch T is connected in parallel with the branch selection switch S _n after the emitter of the IGBT switch T is connected in series with the inductance coil L, and the gate of the IGBT switch T is connected to the corresponding control signal output pin of the circuit control module or an interface, each of the branch selection switch tubes S _n is connected in series in one of the controlled pre-charging circuits. 2. The multi-channel intelligent control circuit for high-voltage distribution box according to claim 1, further comprising an input voltage sensor V1 and an output voltage sensor V2, the input voltage sensor V1 is connected in parallel with the filter capacitor C, and the One end of the output voltage sensor V2 is connected to the anode of the diode D, and the other end of the output voltage sensor V2 is connected between the inductance coil L and the branch selection switch _Sn connected in parallel. 3. The multi-channel intelligent control circuit for high voltage distribution box according to claim 2, wherein the circuit control module comprises: The memory is used to store the program code of the processing process in the multi-channel intelligent control method; The processor is used to execute the program codes of the processing process in the multi-channel intelligent control method. 4. A multi-channel intelligent control method for a high-voltage distribution box, using the multi-channel intelligent control circuit for a high-voltage distribution box according to any one of claims 1 to 2, characterized in that it includes: The gate signal is controlled to enable the controlled pre-charging circuit, and a pulse width modulation wave is formed to adjust the power conversion circuit to output the pre-charging power signal. 5. The multi-channel intelligent control method for high-voltage distribution box as claimed in claim 4, characterized in that it comprises a pre-charging control process: Turn on a branch selection switch tube _Sx according to the strobe signal to form an IGBT switch tube T-inductance coil L-determine the pre-charging current path of the load; Perform current and voltage control on the IGBT switch tube T to stabilize the output voltage U _o at the control target voltage U _o.ref ; When the output voltage U _o ≥ the control target voltage U _o.ref , the pre-charging of the pre-charging current path is completed, the pmw control of the IGBT switch T is stopped, the circuit selection switch Sx is disabled, the pre-charging current path is disconnected, and the corresponding distribution The main contactor in the electric branch circuit is controlled to connect the power distribution branch circuit; When the output voltage U _o ≥ control target voltage U _o.ref cannot be reached all the time, it enters the failure processing mode. 6. The multi-channel intelligent control method for high-voltage distribution boxes according to claim 5, wherein the pre-charging control process includes a double closed-loop control strategy: a. Set the precharge voltage error quantization process V _comp to compare the difference between the output voltage U _o and the control target voltage U _o.ref to form a voltage deviation quantization signal; b. Set the voltage closed-loop control process C _V to form the output current saturation value (iL.max), adjust the output voltage U _o according to the voltage deviation quantization signal, and form the output current desaturation according to the voltage deviation quantization signal; c. Set the inductance current error calculation process _Icomp , which is used to compare the difference between the output current iL and the output current saturation value to form a current deviation quantization signal; d. Set the current closed-loop control process C _I for forming a pmw wave signal according to the current deviation quantization signal; e. Set the IGBT switch control process PWM, which is used to control the IGBT switch tube T to output a pulse power signal according to the pmw wave signal to form an output current iL and an output voltage U _o . 7. The multi-channel intelligent control method for a high-voltage distribution box as claimed in claim 5, wherein the control target voltage U _o . 90% of voltage UH. 8. The multi-channel intelligent control method for high-voltage distribution box as claimed in claim 4, characterized in that, it comprises a distribution branch circuit detection process: Set the number of detection process cycles according to the number of branch selection switch tubes S _n , to detect the voltage change of each power distribution branch; In each detection process, the control branch selects the switching tube S _x to enable to form a corresponding pre-charging current path; at this time, the IGBT switching tube T does not output a power signal; After the delay is determined, the voltage data of the corresponding power distribution branch is indirectly obtained by sampling the voltage of the pre-charging current path, and then the branch selection switch S _x is disabled to disconnect the corresponding pre-charging current path. 9. The multi-channel intelligent control method for a high-voltage distribution box as claimed in claim 4, characterized in that it includes a power-off control process for a distribution branch circuit: On-demand control determines that the main contactor of the power distribution branch is disconnected; After the time delay is determined, the branch selection switch S _x corresponding to the determined power distribution branch is enabled to form a corresponding pre-charging current path; at this time, the IGBT switch T does not output a power signal; When the output voltage U _o of the pre-charging current path drops, the branch selection switch S _x corresponding to the determined power distribution branch is disabled, and it is judged that the disconnection of the determined power distribution branch is completed; When the output voltage U _o of the precharge current path is maintained, it enters the fault handling mode.

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