Braking circuit and braking system control method for heavy-duty vehicle

Abstract

The present invention provides a braking circuit and braking system control method for a heavy-duty vehicle, wherein the braking circuit includes: a power supply; a motor controller, wherein the first phase includes a first IGBT chip and a second IGBT chip; the second phase includes a third IGBT chip and a fourth IGBT chip; the third phase includes a fifth IGBT chip and a sixth IGBT chip; a three-phase load, including a first load circuit, a second load circuit and a third load circuit, wherein the first load circuit is connected to a first electrical connection end and the other end is connected to a second electrical connection end; the second load circuit is connected to the first electrical connection end and the other end is connected to the third electrical connection end; the third load circuit is connected to the second electrical connection end and the other end is connected to the third electrical connection end; when the heavy-duty vehicle brakes, redundant power overflows from the power supply to the motor controller and is transmitted to the three-phase load to consume the redundant power. After adopting the above technical solution, a larger braking output power can be allowed, which is more friendly in failure mode.

Description

Technical Field

[0001] The invention relates to the field of motor control, and in particular to a braking circuit and a braking system control method for a heavy-duty vehicle. Background Art

[0002] Heavy vehicles, such as electric heavy trucks, often have a continuous downhill working mode during use. In this working mode, continuous feedback is required to generate the motor's braking torque, and the braking energy will be recovered to replenish the battery. When the battery is full, the inverter and resistor are needed to consume this excess energy.

[0003] Therefore, the traditional braking circuit is constructed using discrete components, which results in high costs due to factors such as batch production, and low component utilization.

[0004] Therefore, a new type of braking circuit and braking system control method for heavy-duty vehicles is needed, which can have redundancy and reduce the cost of the system. Summary of the invention

[0005] In order to overcome the above technical defects, the purpose of the present invention is to provide a braking circuit and a braking system control method for a heavy-duty vehicle, which can allow a larger braking output power and is more friendly in failure mode.

[0006] The invention discloses a braking circuit for a heavy-duty vehicle, comprising:

[0007] Power supply, provided on the brake circuit;

[0008] The motor controller is connected in parallel to both ends of the power supply, including the first phase, the second phase, and the third phase forming a three-phase circuit, wherein

[0009] The first phase includes a first IGBT chip and a second IGBT chip which are connected to each other and are connected in parallel to a brake circuit;

[0010] The second phase includes a third IGBT chip and a fourth IGBT chip which are connected to each other and are connected in parallel to a brake circuit;

[0011] The third phase includes a fifth IGBT chip and a sixth IGBT chip which are connected to each other and are connected in parallel to the brake circuit;

[0012] The three-phase load includes a first load circuit, a second load circuit and a third load circuit, wherein

[0013] One end of the first load circuit is connected to a first electrical connection end between the first IGBT chip and the second IGBT chip, and the other end is connected to a second electrical connection end between the third IGBT chip and the fourth IGBT chip;

[0014] One end of the second load circuit is connected to the first electrical connection end between the first IGBT chip and the second IGBT chip, and the other end is connected to the third electrical connection end between the fifth IGBT chip and the sixth IGBT chip;

[0015] One end of the third load circuit is connected to the second electrical connection end between the third IGBT chip and the fourth IGBT chip, and the other end is connected to the third electrical connection end between the third IGBT chip and the fourth IGBT chip;

[0016] When the heavy vehicle brakes to generate regenerative power, the redundant power in the regenerative power overflows from the power supply to the motor controller and is simultaneously transmitted to the three-phase load, and the first load circuit, the second load circuit and the third load circuit consume the redundant power.

[0017] Preferably, the first load circuit comprises a first load resistor, a second load resistor, a first inductor, and a first capacitor, the first load resistor and the second load resistor are connected in series between the first electrical connection end and the second electrical connection end, the first inductor is connected in series between the first load resistor and the second load resistor, one end of the first capacitor is connected between the first inductor and the first load resistor, and the other end is grounded;

[0018] The second load circuit includes a third load resistor, a fourth load resistor, a second inductor, and a second capacitor, wherein the third load resistor and the fourth load resistor are connected in series between the first electrical connection end and the third electrical connection end, the second inductor is connected in series between the third load resistor and the fourth load resistor, one end of the second capacitor is connected between the second inductor and the third load resistor, and the other end is grounded;

[0019] The third load circuit includes a fifth load resistor, a sixth load resistor, a third inductor, and a third capacitor, wherein the fifth load resistor and the sixth load resistor are connected in series between the second electrical connection end and the third electrical connection end, the third inductor is connected in series between the fifth load resistor and the sixth load resistor, one end of the third capacitor is connected between the third inductor and the fifth load resistor, and the other end is grounded;

[0020] The three-phase load is Y-shaped or △-shaped.

[0021] Preferably, the resistance values ​​of the first load resistor, the second load resistor, the third load resistor, the fourth load resistor, the fifth load resistor, and the sixth load resistor are equal;

[0022] The inductance values ​​of the first inductor, the second inductor and the third inductor are equal;

[0023] The capacitances of the first capacitor, the second capacitor and the third capacitor are equal.

[0024] Preferably, the motor controller presets a duty cycle of 0.5 for the first IGBT chip, the second IGBT chip, the third IGBT chip, the fourth IGBT chip, the fifth IGBT chip, and the sixth IGBT chip, or

[0025] The motor controller has a preset power-duty cycle curve, which is symmetrical with a straight line of duty cycle 0.5;

[0026] The motor controller searches for the corresponding first duty cycle and second duty cycle in the power-duty cycle curve based on the redundant power, and the motor controller staggers the duty cycles of the first IGBT chip and the second IGBT chip to be the first duty cycle and the second duty cycle, staggers the duty cycles of the third IGBT chip and the fourth IGBT chip to be the first duty cycle and the second duty cycle, and staggers the duty cycles of the fifth IGBT chip and the third IGBT chip to be the first duty cycle and the second duty cycle;

[0027] Moreover, at the same time, the duty cycles of the first IGBT chip, the third IGBT chip and the fifth IGBT chip are different, and the duty cycles of the second IGBT chip, the fourth IGBT chip and the sixth IGBT chip are different.

[0028] Preferably, when any one of the first IGBT chip, the second IGBT chip, the third IGBT chip, the fourth IGBT chip, the fifth IGBT chip, and the sixth IGBT chip is disconnected, another IGBT chip connected to the disconnected IGBT chip in the same phase is controlled to be normally open, and the other two phases operate in buck mode.

[0029] The present invention also discloses a braking system control method for a heavy-duty vehicle, comprising the following steps:

[0030] A braking circuit is configured, including: a power supply, which is arranged on the braking circuit; a motor controller, which is connected in parallel to both ends of the power supply, including a first phase, a second phase, and a third phase forming a three-phase circuit, wherein the first phase includes a first IGBT chip and a second IGBT chip connected to each other and connected to the braking circuit in parallel; the second phase includes a third IGBT chip and a fourth IGBT chip connected to each other and connected to the braking circuit in parallel; the third phase includes a fifth IGBT chip and a sixth IGBT chip connected to each other and connected to the braking circuit in parallel; a three-phase load, including a first load circuit, a second load circuit, and a third load circuit, wherein one end of the first load circuit is connected to a first electrical connection end between the first IGBT chip and the second IGBT chip, and the other end is connected to a second electrical connection end between the third IGBT chip and the fourth IGBT chip;

[0031] One end of the second load circuit is connected to the first electrical connection end between the first IGBT chip and the second IGBT chip, and the other end is connected to the third electrical connection end between the fifth IGBT chip and the sixth IGBT chip; one end of the third load circuit is connected to the second electrical connection end between the third IGBT chip and the fourth IGBT chip, and the other end is connected to the third electrical connection end between the third IGBT chip and the fourth IGBT chip;

[0032] When the heavy vehicle brakes to generate regenerative power, the redundant power in the regenerative power overflows from the power supply to the motor controller and is simultaneously transmitted to the three-phase load, and the first load circuit, the second load circuit and the third load circuit consume the redundant power.

[0033] Preferably, the first load circuit comprises a first load resistor, a second load resistor, a first inductor, and a first capacitor, the first load resistor and the second load resistor are connected in series between the first electrical connection end and the second electrical connection end, the first inductor is connected in series between the first load resistor and the second load resistor, one end of the first capacitor is connected between the first inductor and the first load resistor, and the other end is grounded;

[0034] The second load circuit includes a third load resistor, a fourth load resistor, a second inductor, and a second capacitor, wherein the third load resistor and the fourth load resistor are connected in series between the first electrical connection end and the third electrical connection end, the second inductor is connected in series between the third load resistor and the fourth load resistor, one end of the second capacitor is connected between the second inductor and the third load resistor, and the other end is grounded;

[0035] The third load circuit includes a fifth load resistor, a sixth load resistor, a third inductor, and a third capacitor, wherein the fifth load resistor and the sixth load resistor are connected in series between the second electrical connection end and the third electrical connection end, the third inductor is connected in series between the fifth load resistor and the sixth load resistor, one end of the third capacitor is connected between the third inductor and the fifth load resistor, and the other end is grounded;

[0036] The three-phase load is Y-shaped or △-shaped.

[0037] Preferably, the resistance values ​​of the first load resistor, the second load resistor, the third load resistor, the fourth load resistor, the fifth load resistor, and the sixth load resistor are equal;

[0038] The inductance values ​​of the first inductor, the second inductor and the third inductor are equal;

[0039] The capacitances of the first capacitor, the second capacitor and the third capacitor are equal.

[0040] Preferably, the method further comprises the following steps:

[0041] The motor controller sets a preset duty cycle of 0.5 for the first IGBT chip, the second IGBT chip, the third IGBT chip, the fourth IGBT chip, the fifth IGBT chip, and the sixth IGBT chip, or

[0042] The motor controller has a preset power-duty cycle curve, which is symmetrical with a straight line of duty cycle 0.5;

[0043] The motor controller searches for the corresponding first duty cycle and second duty cycle in the power-duty cycle curve based on the redundant power, and the motor controller staggers the duty cycles of the first IGBT chip and the second IGBT chip to be the first duty cycle and the second duty cycle, staggers the duty cycles of the third IGBT chip and the fourth IGBT chip to be the first duty cycle and the second duty cycle, and staggers the duty cycles of the fifth IGBT chip and the third IGBT chip to be the first duty cycle and the second duty cycle;

[0044] Moreover, at the same time, the duty cycles of the first IGBT chip, the third IGBT chip and the fifth IGBT chip are different, and the duty cycles of the second IGBT chip, the fourth IGBT chip and the sixth IGBT chip are different.

[0045] Preferably, the method further comprises the following steps:

[0046] When any one of the first IGBT chip, the second IGBT chip, the third IGBT chip, the fourth IGBT chip, the fifth IGBT chip, and the sixth IGBT chip is disconnected, another IGBT chip connected to the disconnected IGBT chip in the same phase is controlled to be normally open, and the other two phases operate in buck mode.

[0047] Compared with the prior art, the above technical solution has the following beneficial effects:

[0048] 1. The energy absorption effect is achieved by reusing simple hardware structures that were previously considered completely unusable, and the cost is lower;

[0049] 2. Reduce the switching frequency, enhance the power output capacity, and reduce the cost per unit power;

[0050] 3. It has the ability to work in redundant state, which improves the safety performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 The equivalent topological diagram of the braking circuit in accordance with a preferred embodiment of the present invention is

[0052] Figure 2 The topological diagram of the braking circuit in a preferred embodiment of the present invention is shown in FIG. DETAILED DESCRIPTION

[0053] The advantages of the present invention are further described below in conjunction with the accompanying drawings and specific embodiments.

[0054] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. Instead, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.

[0055] The terms used in this disclosure are for the purpose of describing specific embodiments only and are not intended to limit the disclosure. The singular forms of "a", "said" and "the" used in this disclosure and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0056] It should be understood that although the terms first, second, third, etc. may be used in the present disclosure to describe various information, such information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present disclosure, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0057] In the description of the present invention, it is necessary to understand that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0058] In the description of the present invention, unless otherwise specified and limited, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the internal connection between two components. It can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances.

[0059] In the following description, the suffixes such as "module", "component" or "unit" used to represent elements are only used to facilitate the description of the present invention, and have no specific meanings. Therefore, "module" and "component" can be used interchangeably.

[0060] See also Figure 1 and Figure 2 , shows a braking circuit for a heavy-duty vehicle in accordance with a preferred embodiment of the present invention. When driving, a heavy-duty vehicle will encounter a scenario different from that of a household or commercial vehicle, that is, the working environment of a heavy-duty vehicle is mostly in the mountains, and it is used to transport mineral materials. Therefore, when the heavy-duty vehicle is transporting downhill, it will be on a long downhill road. When in this driving state, the heavy-duty vehicle will be in a long-term braking state. It can be understood that when the brake disc is braked, the torque energy of the brake disc on the caliper will be recovered and charged to the large battery or small battery in the heavy-duty vehicle. Once the battery is fully charged, but the heavy-duty vehicle is still in the process of braking, the torque energy generated will be wasted, and even cause additional heat to the motor. Therefore, in order to reasonably dissipate this energy, the braking circuit includes:

[0061] -power supply

[0062] The power source, such as a battery or a battery pack, is a device installed in a heavy-duty vehicle to provide electrical energy output for the heavy-duty vehicle. When the power in the power source is exhausted, it needs to be recharged. Therefore, the power source is installed in the brake circuit, and the excess torque energy is output from the battery.

[0063] -Motor controller

[0064] The motor controller is usually the nerve center connecting the motor and the battery, which is used to adjust the various performance of the heavy-duty vehicle. It not only plays a role in ensuring the basic safety and precise control of the heavy-duty vehicle, but also allows the battery and the motor to exert sufficient strength. In this embodiment, the motor controller is different from the original function (or on the basis of the original function), and adds a configuration for dissipating excess energy of the power supply. Specifically, the motor controller is connected in parallel at both ends of the power supply, and has a first phase, a second phase, and a third phase forming a three-phase circuit, that is, the commonly understood U, V, and W phases (the correspondence between the first phase, the second phase, and the third phase and the U, V, and W phases is not limited in the present invention, and any phase can be regarded as the first phase, and so on). The three-phase circuit specifically includes a first phase, a second phase, and a third phase. The first phase includes a first IGBT chip and a second IGBT chip connected to each other; the second phase includes a third IGBT chip and a fourth IGBT chip connected to each other; the third phase includes a fifth IGBT chip and a sixth IGBT chip connected to each other. The above-mentioned first IGBT chip, second IGBT chip, third IGBT chip, fourth IGBT chip, fifth IGBT chip, and sixth IGBT chip are connected in parallel to the braking circuit. When the first IGBT chip, second IGBT chip, third IGBT chip, fourth IGBT chip, fifth IGBT chip, and sixth IGBT chip are turned on or off, they will output an inverter current to the load connected to the motor controller. On the other side of the motor controller, a three-phase load is provided, specifically including a first load circuit, a second load circuit, and a third load circuit. The first load circuit, the second load circuit, and the third load circuit are all composed of devices with reactance, wherein one end of the first load circuit is connected to the first electrical connection end between the first IGBT chip and the second IGBT chip, and the other end is connected to the second electrical connection end between the third IGBT chip and the fourth IGBT chip; one end of the second load circuit is connected to the first electrical connection end between the first IGBT chip and the second IGBT chip, and the other end is connected to the third electrical connection end between the fifth IGBT chip and the sixth IGBT chip; one end of the third load circuit is connected to the second electrical connection end between the third IGBT chip and the fourth IGBT chip, and the other end is connected to the third electrical connection end between the third IGBT chip and the fourth IGBT chip. With the above-mentioned first load circuit, second load circuit, and third load circuit that can be used to consume energy, the excess energy will be dissipated. Especially when heavy-duty vehicles brake to generate feedback power, the redundant power in the feedback power (i.e., the excess energy after the battery is fully charged) overflows from the power supply to the motor controller (it can be understood that the "overflow" here is not an overflow in the physical sense, but the energy received beyond the upper limit of the total energy that can be accommodated), and is simultaneously transmitted to the three-phase load, and the first load circuit, the second load circuit and the third load circuit consume the redundant power.

[0065] It is understandable that for those skilled in the art, when the output end of the motor controller is connected to a load, the output voltage of the motor controller will no longer be sinusoidal, and may even have a DC component, which is completely contrary to the normal use requirements of the motor controller and the inverter having the motor controller (in normal use, the output voltage of the motor controller should be a standard sinusoidal type, or all output rectification of the motor controller is to remove the ripple of the sinusoidal waveform). However, for heavy-duty vehicles, and in special applications of pure loads when going downhill, it will be applicable. In other words, such a design is contrary to the conventional cognition of those skilled in the art.

[0066] In a preferred embodiment, the three-phase load is configured as follows: the first load circuit includes a first load resistor, a second load resistor, a first inductor, and a first capacitor; the first load resistor and the second load resistor are connected in series between the first electrical connection end and the second electrical connection end; the first inductor is connected in series between the first load resistor and the second load resistor; one end of the first capacitor is connected between the first inductor and the first load resistor, and the other end is grounded, that is, the first load resistor and the second load resistor will absorb redundant power, the first inductor and the first capacitor will resonate with the current flowing through the first load resistor and the second load resistor, and the entire circuit is in a steady state; the second load circuit includes a third load resistor, a fourth load resistor, a second inductor, and a second capacitor; the third load resistor and the fourth load resistor are connected in series between the first electrical connection end and the third electrical connection end, the second inductor is connected in series between the third load resistor and the fourth load resistor, and the second inductor is connected in series between the third load resistor and the fourth load resistor. One end of the capacitor is connected between the second inductor and the third load resistor, and the other end is grounded, that is, the third load resistor and the fourth load resistor will absorb redundant power, the second inductor and the second capacitor will resonate with the current flowing through the third load resistor and the fourth load resistor, and the entire circuit is in a steady state; the third load circuit includes a fifth load resistor, a sixth load resistor, a third inductor, and a third capacitor, the fifth load resistor and the sixth load resistor are connected in series between the second electrical connection end and the third electrical connection end, the third inductor is connected in series between the fifth load resistor and the sixth load resistor, one end of the third capacitor is connected between the third inductor and the fifth load resistor, and the other end is grounded, that is, the fifth load resistor and the sixth load resistor will absorb redundant power, the third inductor and the third capacitor will resonate with the current flowing through the fifth load resistor and the sixth load resistor, and the entire circuit is in a steady state; finally, the three-phase load can be Y-shaped or △-shaped.

[0067] In order to balance the heat generated on each IGBT chip, the resistance values ​​of the first load resistor, the second load resistor, the third load resistor, the fourth load resistor, the fifth load resistor, and the sixth load resistor are equal; the inductance values ​​of the first inductor, the second inductor, and the third inductor are equal; and the capacitance values ​​of the first capacitor, the second capacitor, and the third capacitor are equal. After the heat is evenly generated on each IGBT chip, more output power can be consumed.

[0068] Preferably, in order to prevent a large amount of heat from accumulating on a certain IGBT chip in a short period of time, the motor controller is configured to preset a duty cycle of 0.5 for the first IGBT chip, the second IGBT chip, the third IGBT chip, the fourth IGBT chip, the fifth IGBT chip, and the sixth IGBT chip, that is, within one period T, the respective on-times of the first IGBT chip and the second IGBT chip are T / 2, the respective on-times of the third IGBT chip and the fourth IGBT chip are T / 2, and the respective on-times of the fifth IGBT chip and the sixth IGBT chip are T / 2. Then, half of the heat generated on the first phase is distributed in the first IGBT chip and the other half is distributed in the second IGBT chip, half of the heat generated on the second phase is distributed in the third IGBT chip and the other half is distributed in the fourth IGBT chip, and half of the heat generated on the third phase is distributed in the fifth IGBT chip and the other half is distributed in the sixth IGBT chip, so as to achieve a thermal balance effect.

[0069] In another embodiment, a power-duty cycle curve is preset in the motor controller, and the curve is a downward-opening parabola (or close to an downward-opening parabola), and each point on the curve represents the power consumed by a certain IGBT chip at the duty cycle represented by the horizontal axis. Therefore, when the motor controller calculates the redundant power based on the torque energy, the motor controller will search in the power-duty cycle curve, that is, substitute the redundant power, and obtain the duty cycle value from the power-duty cycle curve. Since the curve shape of the power-duty cycle curve is similar to the downward-opening parabola, two duty cycle values ​​can be obtained, and under normal conditions, the power-duty cycle curve is symmetrical with a straight line with a duty cycle of 0.5, so the values ​​of these two duty cycles should be 1. After obtaining the values ​​of the two duty cycles, they are recorded as the first duty cycle and the second duty cycle. The motor controller alternately controls the duty cycles of the first IGBT chip and the second IGBT chip to be the first duty cycle and the second duty cycle, respectively. A period (which may be the same as T, or a different duration T') can be set. During the period, half of the time, the duty cycle of the first IGBT chip is controlled to be the first duty cycle (for example, 0.2), and the other half of the time, the duty cycle of the first IGBT chip is controlled to be the second duty cycle (for example, 0.8). Similarly, half of the time, the duty cycle of the second IGBT chip is controlled to be the second duty cycle (at this time, the duty cycle of the first IGBT chip is the first duty cycle), and the other half of the time, the duty cycle of the second IGBT chip is controlled to be the first duty cycle (at this time, the duty cycle of the first IGBT chip is the second duty cycle). On the other hand, similarly, the motor controller staggers the duty ratios of the third IGBT chip and the fourth IGBT chip to be the first duty ratio and the second duty ratio, and staggers the duty ratios of the fifth IGBT chip and the third IGBT chip to be the first duty ratio and the second duty ratio, respectively (the control method may be as above). By alternating the modulation ratios of the high zone and the low zone, the IGBT chips on the same phase can achieve thermal equilibrium (when the duty ratio is low, less heat is generated, which is equivalent to "resting").

[0070] It should be emphasized that, for the motor controller, the duty cycle of the same phase should be set to 0.5, so as to output a sine wave, that is, inconsistent duty cycles of IGBT chips of the same phase are not allowed. However, in this embodiment, such a three-phase load is applicable.

[0071] In another preferred embodiment, when any of the first IGBT chip, the second IGBT chip, the third IGBT chip, the fourth IGBT chip, the fifth IGBT chip, and the sixth IGBT chip is disconnected, the other IGBT chip connected to the disconnected IGBT chip in the same phase (i.e., the pair of the faulty IGBT chip) is controlled to be normally open, and the other two phases are operated in buck mode, so that it can still operate in the event of a fault. The circuit in Buck mode, also known as a step-down circuit, is basically characterized by a DC-DC conversion circuit with an output voltage lower than the input voltage. The input current is pulsating and the output current is continuous. The Buck circuit has three operating modes: CCM, BCM, and DCM. CCM (Continuous Conduction Mode), continuous conduction mode: within a switching cycle, the inductor current never reaches 0. In other words, the inductor never "resets", which means that the inductor flux never returns to 0 within the switching cycle, and when the power tube is closed, there is still current flowing in the coil. DCM, (Discontinuous Conduction Mode) Discontinuous Conduction Mode: During the switching cycle, the inductor current always reaches 0, which means that the inductor is properly "reset", that is, when the power switch is closed, the inductor current is zero. BCM (Boundary Conduction Mode), Boundary or Boundary Line Conduction Mode: The controller monitors the inductor current and once it detects that the current is equal to 0, the power switch is immediately closed. The controller always waits for the inductor current to "reset" to activate the switch. If the inductor current is high and the cut-off slope is quite flat, the switching period is extended, so the BCM converter is a variable frequency system. The BCM converter can be called critical conduction mode or CRM (Critical Conduction Mode).

[0072] The present invention also discloses a braking system control method for a heavy-duty vehicle, comprising the following steps: configuring a braking circuit, comprising: a power supply, arranged on the braking circuit; a motor controller, connected in parallel to both ends of the power supply, comprising a first phase, a second phase, and a third phase forming a three-phase circuit, wherein the first phase comprises a first IGBT chip and a second IGBT chip connected to each other and connected in parallel to the braking circuit; the second phase comprises a third IGBT chip and a fourth IGBT chip connected to each other and connected in parallel to the braking circuit; the third phase comprises a fifth IGBT chip and a sixth IGBT chip connected to each other and connected in parallel to the braking circuit; a three-phase load, comprising a first load circuit, a second load circuit, and a third load circuit, wherein one end of the first load circuit is connected to the first IGBT chip and the second IGB T chip, and the other end is connected to the second electrical connection end between the third IGBT chip and the fourth IGBT chip; one end of the second load circuit is connected to the first electrical connection end between the first IGBT chip and the second IGBT chip, and the other end is connected to the third electrical connection end between the fifth IGBT chip and the sixth IGBT chip; one end of the third load circuit is connected to the second electrical connection end between the third IGBT chip and the fourth IGBT chip, and the other end is connected to the third electrical connection end between the third IGBT chip and the fourth IGBT chip; when the heavy-duty vehicle brakes to form feedback power, the redundant power in the feedback power overflows from the power supply to the motor controller, and is simultaneously transmitted to the three-phase load, and the first load circuit, the second load circuit and the third load circuit consume the redundant power.

[0073] Preferably, the first load circuit includes a first load resistor, a second load resistor, a first inductor, and a first capacitor, the first load resistor and the second load resistor are connected in series between the first electrical connection end and the second electrical connection end, the first inductor is connected in series between the first load resistor and the second load resistor, one end of the first capacitor is connected between the first inductor and the first load resistor, and the other end is grounded; the second load circuit includes a third load resistor, a fourth load resistor, a second inductor, and a second capacitor, the third load resistor and the fourth load resistor are connected in series between the first electrical connection end and the third electrical connection end, the second inductor is connected in series between the third load resistor and the fourth load resistor, one end of the second capacitor is connected between the second inductor and the third load resistor, and the other end is grounded; the third load circuit includes a fifth load resistor, a sixth load resistor, a third inductor, and a third capacitor, the fifth load resistor and the sixth load resistor are connected in series between the second electrical connection end and the third electrical connection end, the third inductor is connected in series between the fifth load resistor and the sixth load resistor, one end of the third capacitor is connected between the third inductor and the fifth load resistor, and the other end is grounded; the three-phase load is Y-shaped or △-shaped.

[0074] Preferably, the resistance values ​​of the first load resistor, the second load resistor, the third load resistor, the fourth load resistor, the fifth load resistor and the sixth load resistor are equal; the inductance values ​​of the first inductor, the second inductor and the third inductor are equal; and the capacitance values ​​of the first capacitor, the second capacitor and the third capacitor are equal.

[0075] Preferably, the following steps are also included: the motor controller presets a duty cycle of 0.5 for the first IGBT chip, the second IGBT chip, the third IGBT chip, the fourth IGBT chip, the fifth IGBT chip, and the sixth IGBT chip, or a power-duty cycle curve is preset in the motor controller, and the power-duty cycle curve is symmetrical about a straight line with a duty cycle of 0.5; the motor controller searches for the corresponding first duty cycle and second duty cycle in the power-duty cycle curve based on redundant power, and the motor controller alternately controls the duty cycles of the first IGBT chip and the second IGBT chip to be the first duty cycle and the second duty cycle, alternately controls the duty cycles of the third IGBT chip and the fourth IGBT chip to be the first duty cycle and the second duty cycle, and alternately controls the duty cycles of the fifth IGBT chip and the third IGBT chip to be the first duty cycle and the second duty cycle, respectively; and at the same time, the duty cycles of the first IGBT chip, the third IGBT chip and the fifth IGBT chip are different, and the duty cycles of the second IGBT chip, the fourth IGBT chip and the sixth IGBT chip are different.

[0076] Preferably, the following steps are also included: when any one of the first IGBT chip, the second IGBT chip, the third IGBT chip, the fourth IGBT chip, the fifth IGBT chip, and the sixth IGBT chip is disconnected, another IGBT chip connected to the disconnected IGBT chip in the same phase is controlled to be normally open, and the other two phases operate in buck mode.

[0077] It should be noted that the embodiments of the present invention have better practicability and do not impose any form of limitation on the present invention. Any technician familiar with the field may use the technical content disclosed above to change or modify it into an equivalent effective embodiment. However, any modification or equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A braking circuit for a heavy vehicle, characterized in that: The braking circuit comprises: Power supply, provided on the brake circuit; The motor controller is connected in parallel to the two ends of the power supply, including the first phase, the second phase, and the third phase forming a three-phase circuit, wherein The first phase includes a first IGBT chip and a second IGBT chip connected to each other and connected in parallel to a brake circuit; the second phase includes a third IGBT chip and a fourth IGBT chip connected to each other and connected in parallel to a brake circuit; the third phase includes a fifth IGBT chip and a sixth IGBT chip connected to each other and connected in parallel to a brake circuit; the three-phase load includes a first load circuit, a second load circuit and a third load circuit, wherein One end of the first load circuit is connected to a first electrical connection end between the first IGBT chip and the second IGBT chip, and the other end is connected to a second electrical connection end between the third IGBT chip and the fourth IGBT chip; One end of the second load circuit is connected to a first electrical connection end between the first IGBT chip and the second IGBT chip, and the other end is connected to a third electrical connection end between the fifth IGBT chip and the sixth IGBT chip; One end of the third load circuit is connected to the second electrical connection end between the third IGBT chip and the fourth IGBT chip, and the other end is connected to the third electrical connection end between the third IGBT chip and the fourth IGBT chip; When the heavy-duty vehicle brakes to generate feedback power, the redundant power in the feedback power overflows from the power supply to the motor controller and is simultaneously transmitted to the three-phase load. The first load circuit, the second load circuit and the third load circuit consume the redundant power.

2. The brake circuit according to claim 1, characterized in that The first load circuit comprises a first load resistor, a second load resistor, a first inductor, and a first capacitor, wherein the first load resistor and the second load resistor are connected in series between the first electrical connection end and the second electrical connection end, the first inductor is connected in series between the first load resistor and the second load resistor, one end of the first capacitor is connected between the first inductor and the first load resistor, and the other end is grounded; The second load circuit comprises a third load resistor, a fourth load resistor, a second inductor, and a second capacitor, wherein the third load resistor and the fourth load resistor are connected in series between the first electrical connection end and the third electrical connection end, the second inductor is connected in series between the third load resistor and the fourth load resistor, and one end of the second capacitor is connected between the second inductor and the third load resistor, and the other end is grounded; The third load circuit comprises a fifth load resistor, a sixth load resistor, a third inductor, and a third capacitor, wherein the fifth load resistor and the sixth load resistor are connected in series between the second electrical connection end and the third electrical connection end, the third inductor is connected in series between the fifth load resistor and the sixth load resistor, one end of the third capacitor is connected between the third inductor and the fifth load resistor, and the other end is grounded; The three-phase load is in a Y shape or a △ shape.

3. The brake circuit according to claim 2, characterized in that The resistance values ​​of the first load resistor, the second load resistor, the third load resistor, the fourth load resistor, the fifth load resistor and the sixth load resistor are equal; The inductance values ​​of the first inductor, the second inductor and the third inductor are equal; The capacitances of the first capacitor, the second capacitor and the third capacitor are equal.

4. The brake circuit according to claim 1, characterized in that The motor controller presets a duty cycle of 0.5 for the first IGBT chip, the second IGBT chip, the third IGBT chip, the fourth IGBT chip, the fifth IGBT chip, and the sixth IGBT chip, or A power-duty cycle curve is preset in the motor controller, and the power-duty cycle curve is symmetrical with a straight line having a duty cycle of 0.5; The motor controller searches for the corresponding first duty cycle and second duty cycle in the power-duty cycle curve based on the redundant power, and the motor controller staggeredly controls the duty cycles of the first IGBT chip and the second IGBT chip to be the first duty cycle and the second duty cycle respectively, staggeredly controls the duty cycles of the third IGBT chip and the fourth IGBT chip to be the first duty cycle and the second duty cycle respectively, and staggeredly controls the duty cycles of the fifth IGBT chip and the third IGBT chip to be the first duty cycle and the second duty cycle respectively; Moreover, at the same time, the duty cycles of the first IGBT chip, the third IGBT chip and the fifth IGBT chip are different, and the duty cycles of the second IGBT chip, the fourth IGBT chip and the sixth IGBT chip are different.

5. The brake circuit according to claim 1, characterized in that When any one of the first IGBT chip, the second IGBT chip, the third IGBT chip, the fourth IGBT chip, the fifth IGBT chip, and the sixth IGBT chip is disconnected, another IGBT chip connected to the disconnected IGBT chip in the same phase is controlled to be normally open, and the other two phases operate in buck mode.

6. A method for controlling a braking system of a heavy vehicle, characterized in that: The following steps are involved: A braking circuit is configured, comprising: a power supply, arranged on the braking circuit; A motor controller is connected in parallel to both ends of the power supply, including a first phase, a second phase, and a third phase forming a three-phase circuit, wherein the first phase includes a first IGBT chip and a second IGBT chip connected to each other and connected in parallel to a brake circuit; the second phase includes a third IGBT chip and a fourth IGBT chip connected to each other and connected in parallel to the brake circuit; the third phase includes a fifth IGBT chip and a sixth IGBT chip connected to each other and connected in parallel to the brake circuit; a three-phase load includes a first load circuit, a second load circuit, and a third load circuit, wherein one end of the first load circuit is connected to a first electrical connection end between the first IGBT chip and the second IGBT chip, and the other end is connected to a second electrical connection end between the third IGBT chip and the fourth IGBT chip; one end of the second load circuit is connected to a first electrical connection end between the first IGBT chip and the second IGBT chip, and the other end is connected to a third electrical connection end between the fifth IGBT chip and the sixth IGBT chip; one end of the third load circuit is connected to a second electrical connection end between the third IGBT chip and the fourth IGBT chip, and the other end is connected to a third electrical connection end between the third IGBT chip and the fourth IGBT chip; When the heavy-duty vehicle brakes to generate feedback power, the redundant power in the feedback power overflows from the power supply to the motor controller and is simultaneously transmitted to the three-phase load. The first load circuit, the second load circuit and the third load circuit consume the redundant power.

7. The brake system control method according to claim 6, characterized in that: The first load circuit comprises a first load resistor, a second load resistor, a first inductor, and a first capacitor, wherein the first load resistor and the second load resistor are connected in series between the first electrical connection end and the second electrical connection end, the first inductor is connected in series between the first load resistor and the second load resistor, one end of the first capacitor is connected between the first inductor and the first load resistor, and the other end is grounded; The second load circuit comprises a third load resistor, a fourth load resistor, a second inductor, and a second capacitor, wherein the third load resistor and the fourth load resistor are connected in series between the first electrical connection end and the third electrical connection end, the second inductor is connected in series between the third load resistor and the fourth load resistor, and one end of the second capacitor is connected between the second inductor and the third load resistor, and the other end is grounded; The third load circuit comprises a fifth load resistor, a sixth load resistor, a third inductor, and a third capacitor, wherein the fifth load resistor and the sixth load resistor are connected in series between the second electrical connection end and the third electrical connection end, the third inductor is connected in series between the fifth load resistor and the sixth load resistor, one end of the third capacitor is connected between the third inductor and the fifth load resistor, and the other end is grounded; The three-phase load is in a Y shape or a △ shape.

8. The brake system control method according to claim 7, characterized in that: The resistance values ​​of the first load resistor, the second load resistor, the third load resistor, the fourth load resistor, the fifth load resistor and the sixth load resistor are equal; The inductance values ​​of the first inductor, the second inductor and the third inductor are equal; The capacitances of the first capacitor, the second capacitor and the third capacitor are equal.

9. The brake system control method according to claim 6, characterized in that: The following steps are also included: The motor controller presets a duty cycle of 0.5 for the first IGBT chip, the second IGBT chip, the third IGBT chip, the fourth IGBT chip, the fifth IGBT chip, and the sixth IGBT chip, or A power-duty cycle curve is preset in the motor controller, and the power-duty cycle curve is symmetrical with a straight line having a duty cycle of 0.5; The motor controller searches for the corresponding first duty cycle and second duty cycle in the power-duty cycle curve based on the redundant power, and the motor controller staggeredly controls the duty cycles of the first IGBT chip and the second IGBT chip to be the first duty cycle and the second duty cycle respectively, staggeredly controls the duty cycles of the third IGBT chip and the fourth IGBT chip to be the first duty cycle and the second duty cycle respectively, and staggeredly controls the duty cycles of the fifth IGBT chip and the third IGBT chip to be the first duty cycle and the second duty cycle respectively; Moreover, at the same time, the duty cycles of the first IGBT chip, the third IGBT chip and the fifth IGBT chip are different, and the duty cycles of the second IGBT chip, the fourth IGBT chip and the sixth IGBT chip are different.

10. The brake system control method according to claim 6, characterized in that: The following steps are also included: When any one of the first IGBT chip, the second IGBT chip, the third IGBT chip, the fourth IGBT chip, the fifth IGBT chip, and the sixth IGBT chip is disconnected, another IGBT chip connected to the disconnected IGBT chip in the same phase is controlled to be normally open, and the other two phases operate in buck mode.

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