Control circuit and control method for electric control switch, and electric vehicle

Abstract

A control circuit for an electric control switch. The control circuit comprises: a flip-flop chip, which receives a real-time control signal and a PWM signal, and outputs a first control signal, wherein the control signal is configured as a signal for initially controlling an electric control switch to be turned on or off; and a logic AND gate chip, which receives the first control signal and a safety status signal, and outputs a second control signal, wherein the safety status signal is configured to indicate whether a power management chip is in a normal state, and the second control signal is configured as a signal for finally controlling a relay to be turned on or off, it is only when the safety status signal is a normal status level value that the PWM signal can be continuously refreshed to generate a trigger signal, and when a control unit is accidentally reset, the PWM signal is no longer refreshed, the trigger signal is no longer generated, and the safety status signal maintains the normal state level value within a preset time.

Description

Control circuits for electronically controlled switches, electric vehicles and control methods Technical Field

[0001] This invention relates to the field of electronic switch control technology, and in particular to a control circuit for an electronic switch, an electric vehicle, and a control method for an electronic switch. Background Technology

[0002] Electronic switches are a crucial component of electrical circuits, especially in new energy vehicles. Taking new energy vehicles as an example, electronic switches are used to control the on / off state of circuits. For instance, they can be used in high-voltage circuits to connect or disconnect high-voltage components such as the power battery and drive motor. Electronic switches also provide isolation between circuits, ensuring circuit safety and stability, which is of great significance for guaranteeing the safety and reliability of the entire vehicle (i.e., new energy vehicles). An example of an electronic switch is a relay.

[0003] In existing technologies, the I / O ports (i.e., the input / output ports of the control unit, used to connect the control unit to external circuits or vice versa) of the control unit (e.g., a microcontroller) are typically directly connected to the drive circuit of the electronic switch. Thus, the signal output by the control unit can directly control the closing or opening of the electronic switch. In this control method, the closing or opening of the electronic switch is only controlled by the I / O ports of the control unit; no safety status signal from the power management chip is involved in the control. When the program malfunctions (e.g., the control unit is interfered with, causing the program to deviate from its normal running path) or when I / O is stuck (e.g., due to improper control unit configuration, the data transmission speed cannot keep up with the read / write recognition speed), the electronic switch may not close or open as expected.

[0004] More specifically, during the period when the electronic control switch is closed, such as during high-speed driving of an electric vehicle (i.e., a new energy vehicle), there may be situations such as data overflow or watchdog timer anomalies, which can cause program crashes. Alternatively, the electric vehicle may be driving in harsh external environments, such as strong electromagnetic fields, high temperatures, or vibrations, leading to an unexpected reset of the control unit and a low-level signal from the I / O port output. In the above control method, since the control unit's I / O port directly controls the electronic control switch (e.g., a relay), once the control unit resets, the electronic control switch immediately applies high voltage. The electric vehicle's battery pack and motor are connected via the electronic control switch at high voltage. Applying high voltage to the electronic control switch means the switch is disconnected, interrupting the high-voltage connection between the battery pack and the motor, disconnecting the electric vehicle's power source, and causing an instantaneous loss of power. When an electric vehicle is traveling at high speed on a highway, this sudden loss of power can cause it to decelerate abruptly, leading to rear-end collisions as following vehicles may be unable to brake in time. Therefore, the immediate disconnection of the electronic control switch due to an unexpected reset of the control unit poses a serious safety hazard, especially in the electric vehicle field. Summary of the Invention

[0005] This invention proposes a control circuit for an electronically controlled switch to solve the problem that the electronically controlled switch immediately disconnects when the control unit is accidentally reset in the prior art.

[0006] In a first aspect, embodiments of the present invention disclose a control circuit for an electrically controlled switch, comprising:

[0007] The trigger chip includes a first input port, a second input port, and a first output port. The first input port is configured to receive a real-time control signal from the control unit. The control signal is configured to be a signal that initially controls the closing or opening of the electronic control switch. The second input port is configured to receive a PWM signal from the control unit. The PWM signal includes a trigger signal and a non-trigger signal. The first output port is configured to output a first control signal. The trigger chip is configured to determine whether the first control signal is the control signal at the current moment or the control signal at the previous moment based on whether the current PWM signal is a trigger signal or a non-trigger signal.

[0008] The logic AND gate chip includes a third input port, a fourth input port, and a second output port. The third input port is configured to receive a first control signal output from the first output port of the flip-flop chip. The fourth input port is configured to receive a safety status signal from the power management chip, which is configured to indicate whether the power management chip is in a normal state. The second output port is configured to output a second control signal, which is configured to ultimately control the closing or opening of the electronic switch.

[0009] Specifically, the PWM signal can be continuously refreshed to generate a trigger signal only when the safety status signal is at the normal status level. When the control unit is unexpectedly reset, the PWM signal will no longer be refreshed and will no longer generate a trigger signal. The safety status signal will maintain the normal status level for a preset time.

[0010] By adopting the above technical solution, the present invention can control the validity of the real-time control signal output by the control unit through the PWM signal. When the control unit is accidentally reset, the PWM signal is no longer refreshed. The first control signal determines whether it is the control signal at the current moment or the control signal at the previous moment based on whether the current PWM signal is a trigger signal or a non-trigger signal. The safety state signal maintains the normal state level value within a preset time, thereby delaying the change of the second control signal. Therefore, within the preset time, the electronic control switch can still maintain the state of the previous moment. Thus, when the electronic control switch was originally in the closed state, it will not be immediately opened due to the accidental reset of the control unit, thereby improving the safety and stability of the entire circuit.

[0011] According to another specific embodiment of the present invention, when the control unit is unexpectedly reset and cannot return to normal within a preset time, the safety status signal changes from a normal status level value to an abnormal status level value.

[0012] According to another specific embodiment of the present invention, when the PWM signal is a trigger signal, the control signal at the current moment is triggered, and the first control signal is the control signal at the current moment; and / or, when the PWM signal is a non-trigger signal, the control signal at the current moment is not triggered, and the first control signal is the control signal at the previous moment.

[0013] According to another specific embodiment of the present invention, when the safety status signal is at the normal status level, the second control signal is determined according to the first control signal.

[0014] According to another specific embodiment of the present invention, the normal state level is high and the abnormal state level is low. When the safety state signal is low, the second control signal is low and the electric control switch is disconnected.

[0015] According to another specific embodiment of the present invention, the trigger signal is a rising edge signal or a falling edge signal. When the safety status signal is high and the PWM signal is a trigger signal, the first control signal and the second control signal are the same as the control signal at the current moment, and / or, when the safety status signal is high and the PWM signal is a non-trigger signal, the first control signal and the second control signal are the same as the control signal at the previous moment.

[0016] According to another specific embodiment of the present invention, when the second control signal is high, the electronic control switch is closed.

[0017] According to another specific embodiment of the present invention, the preset time is 1ms-2s, and / or the duty cycle of the PWM signal is 1-99% and the frequency is 1Hz-100KHz, and / or the control unit is a microcontroller, and / or the trigger chip is a D flip-flop chip.

[0018] Secondly, embodiments of the present invention also disclose an electric vehicle, including a control circuit for an electric control switch as described in any of the embodiments of the first aspect, wherein the electric control switch is a relay, and when the relay is closed, the battery pack of the electric vehicle supplies power to the motor of the electric vehicle; when the relay is open, the battery pack of the electric vehicle does not supply power to the motor of the electric vehicle.

[0019] By adopting the above technical solution, the present invention can control the validity of the real-time control signal output by the control unit through the PWM signal. When the control unit is accidentally reset, the PWM signal is no longer refreshed. The first control signal determines whether it is the control signal at the current moment or the control signal at the previous moment based on whether the current PWM signal is a trigger signal or a non-trigger signal. The safety state signal maintains the normal state level value within a preset time, thereby delaying the change of the second control signal. Therefore, within the preset time, the electronic control switch can still maintain the state of the previous moment. Thus, when the electronic control switch was originally in the closed state, it will not be immediately opened due to the accidental reset of the control unit, thereby improving the safety and stability of the entire circuit.

[0020] Thirdly, embodiments of the present invention also disclose a control method for an electrically controlled switch, wherein the electrically controlled switch is controlled using a control circuit for an electrically controlled switch as described in any of the embodiments of the first aspect, and the control method includes:

[0021] The real-time control signal, PWM signal, and safety status signal are determined. The control signal is configured as a signal to initially control the closing or opening of the power control switch. The PWM signal includes a trigger signal and a non-trigger signal. The safety status signal is configured to indicate whether the power management chip is in a normal state.

[0022] Determine whether the first control signal is the control signal of the current moment or the control signal of the previous moment based on whether the current PWM signal is a trigger signal or a non-trigger signal;

[0023] The second control signal is determined based on the first control signal and the safety status signal, wherein the second control signal is configured as the signal that ultimately controls the closing or opening of the electronic control switch;

[0024] The electronic control switch is closed or opened according to the second control signal;

[0025] Specifically, the PWM signal can be continuously refreshed to generate a trigger signal only when the safety status signal is at the normal status level. When the control unit is unexpectedly reset, the PWM signal will no longer be refreshed and will no longer generate a trigger signal. The safety status signal will maintain the normal status level for a preset time.

[0026] By adopting the above technical solution, the present invention can control the validity of the real-time control signal output by the control unit through the PWM signal. When the control unit is accidentally reset, the PWM signal is no longer refreshed. The first control signal determines whether it is the control signal at the current moment or the control signal at the previous moment based on whether the current PWM signal is a trigger signal or a non-trigger signal. The safety state signal maintains the normal state level value within a preset time, thereby delaying the change of the second control signal. Therefore, within the preset time, the electronic control switch can still maintain the state of the previous moment. Thus, when the electronic control switch was originally in the closed state, it will not be immediately opened due to the accidental reset of the control unit, thereby improving the safety and stability of the entire circuit. Attached Figure Description

[0027] Figure 1 shows a schematic diagram of the control circuit for an electronically controlled switch in an embodiment of the present invention;

[0028] Figure 2 shows a flowchart of the control method for an electronically controlled switch in an embodiment of the present invention. Detailed Implementation

[0029] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Although the description of the present invention is presented in conjunction with preferred embodiments, this does not mean that the features of the invention are limited to these embodiments. On the contrary, the purpose of describing the invention in conjunction with embodiments is to cover other options or modifications that may be derived based on the claims of the present invention. To provide a deep understanding of the invention, many specific details will be included in the following description. The invention may also be implemented without using these details. Furthermore, to avoid confusion or obscuring the focus of the invention, some specific details will be omitted in the description. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0030] It should be noted that in this specification, similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0031] The terms “first”, “second”, etc., are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0032] In the description of this embodiment, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set up," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this embodiment based on the specific circumstances.

[0033] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0034] Through careful study of existing technology, the inventors discovered that when the control unit is unexpectedly reset, the control signal of the electronic switch emitted by the control unit becomes low-level, causing the electronic switch to immediately disconnect and the related electrical components to immediately stop working. This is particularly problematic in new energy vehicles, where the vehicle is prone to sudden loss of power, leading to accidents. The inventors aim to solve this problem by preventing the electronic switch from immediately disconnecting when the control unit is unexpectedly reset, thus minimizing the risk of accidents.

[0035] The inventors initially conceived of the following embodiment: the control signal for the electronically controlled switch output from the I / O port of the control unit is first ANDed with the safety status signal of the power management chip. The output signal after the operation is connected to the electronically controlled switch drive circuit, thereby controlling the electronically controlled switch to turn off or on. The power management chip that meets functional safety requirements has an SS (Safety Status) pin, which can output a safety status signal. When the power management chip is operating normally, the safety status signal output is high; when the power management chip malfunctions, the safety status signal output is low. This embodiment uses a combinational logic AND gate circuit to AND the drive signal from the control unit to the electronically controlled switch with the safety status signal from the power management chip, and then outputs the result to control the electronically controlled switch. Compared to the control methods of the prior art mentioned in the background section, this embodiment provides an additional layer of protection from the safety status signal, thus improving safety.

[0036] In practical use, the inventors discovered that the control method of the above embodiments still has problems. In the above embodiments, since the control signal of the electric switch and the safety status signal are logically ANDed, if either signal is low, the final output signal will be low. Therefore, the control unit resets, the I / O port output becomes a low-level signal, and the electric switch will immediately apply high voltage. The inventors have made further improvements to address this issue.

[0037] In a first aspect, referring to FIG1, an embodiment of the present invention discloses a control circuit for an electronically controlled switch, including a trigger chip 01 and a logic AND gate chip 02.

[0038] The trigger chip 01 includes a first input port D, a second input port CP, and a first output port Q. The first input port D is configured to receive a real-time control signal from the control unit, which is configured to initially control the closing or opening of the electronically controlled switch. The second input port CP is configured to receive a PWM signal from the control unit, which includes a trigger signal and a non-trigger signal. The first output port Q is configured to output a first control signal. The trigger chip 01 is configured to determine whether the first control signal is the control signal of the current moment or the control signal of the previous moment based on whether the current PWM signal is a trigger signal or a non-trigger signal. In other words, the validity of the control signal at the current moment depends on whether the current PWM signal is a trigger signal or a non-trigger signal. If valid, the first control signal is the same as the control signal at the current moment; if invalid, the first control signal maintains the control signal of the previous moment.

[0039] The AND gate chip 02 includes a third input port B, a fourth input port A, and a second output port Y. The third input port B is configured to receive a first control signal output from the first output port Q of the flip-flop chip 01. The fourth input port A is configured to receive a safety status signal from the power management chip. The second output port Y is configured to output a second control signal. The safety status signal is configured to indicate whether the power management chip is in a normal state; more specifically, a normal state refers to the state in which the power management chip can operate normally and safely. The second control signal is configured to ultimately control the closing or opening of the relay.

[0040] Specifically, the PWM signal can be continuously refreshed to generate a trigger signal only when the safety status signal is at the normal status level. When the control unit is unexpectedly reset, the PWM signal is no longer refreshed and no trigger signal is generated, and the safety status signal maintains the normal status level for a preset time. Specifically, when the power management chip is in normal operation, the safety status signal is at the normal status level.

[0041] In this application, when the control unit is unexpectedly reset, the PWM signal is no longer refreshed and no trigger signal appears. The trigger chip 01 determines whether the first control signal is the control signal at the current moment or the control signal at the previous moment based on whether the current PWM signal is a trigger signal or a non-trigger signal. The safety state signal maintains the normal state level value for a preset time, thereby delaying the change of the second control signal. Therefore, within the preset time, the electronic control switch can still maintain the state of the previous moment. Thus, when the electronic control switch was originally in the closed state, it will not be immediately opened due to the unexpected reset of the control unit, thereby improving the safety and stability of the entire circuit.

[0042] In other words, this invention employs the aforementioned sequential logic circuit and combines it with a flip-flop design, making the effective output of the control signal of the control unit dependent on whether a trigger signal appears in the PWM signal. During an unexpected reset of the control unit, since the PWM signal no longer refreshes and no trigger signal is generated, the safety status signal delay indicates an anomaly, and the second control signal can be delayed and changed. Therefore, the electronic switch will not immediately disconnect, thereby improving the reliability and safety of the entire circuit. By combining the PWM signal, the real-time control signal, and the safety status signal, this invention can prevent the electronic switch from unexpectedly closing or not opening as expected.

[0043] For example, if the control unit is unexpectedly reset and does not recover, the PWM signal will no longer be refreshed and no trigger signal will be generated. When the control unit recovers from the unexpected reset and returns to normal, for example, after detecting that the current state (e.g., vehicle self-test state, vehicle high-voltage request, and vehicle speed) is normal, the PWM signal will continue to be refreshed.

[0044] Furthermore, the PWM signal is issued by the control unit, and the reset mechanism of the corresponding PWM module in the control unit can ensure that the PWM signal will no longer refresh and generate a trigger signal when the control unit is accidentally reset.

[0045] The trigger signal can be selected based on the control unit's settings. Specifically, the trigger signal can be determined based on the control unit's reset mechanism. The trigger signal can be an edge signal; an edge signal refers to the process of a signal rapidly switching from one state to another during signal transmission. For example, if the control unit is configured not to generate a rising edge upon reset, the trigger signal can be set to a rising edge signal; if the control unit is configured not to generate a falling edge upon reset, the trigger signal can be set to a falling edge signal.

[0046] Specifically, during reset, the control unit's pins return to their default states, such as a low level. In this case, the trigger signal can be set to rise-edge valid. That is, when the trigger signal is a rising edge signal, the control signal issued by the control unit at the current moment is valid, and the first control signal output by the trigger chip 01 is the control signal issued by the control unit at the current moment. However, when there is no trigger signal, i.e., no rising edge signal (such as a falling edge signal or a high / low level signal), the control signal issued by the control unit at the current moment is invalid, and the first control signal output by the trigger chip 01 is still the control signal issued by the control unit at the previous moment. In this situation, during reset, the PWM signal becomes low and can remain low; alternatively, the control unit's pins may be stuck, the PWM signal is high, and the PWM signal may continue to remain high or become low after a period of time, without generating a rising edge signal.

[0047] For example, if the default state is high, and the corresponding trigger signal is set to fall-edge valid, then when the trigger signal is a falling-edge signal, the control signal issued by the control unit at the current moment is valid, and the first control signal output by the trigger chip 01 is the control signal issued by the control unit at the current moment. However, when there is no trigger signal, i.e., no falling-edge signal (such as a rising-edge signal or a high / low level signal), the control signal issued by the control unit at the current moment is invalid, and the first control signal output by the trigger chip 01 is still the control signal issued by the control unit at the previous moment. In this case, the control unit pin may also become stuck. Upon reset, the PWM signal becomes high, but the PWM signal may remain high, change from low to high, or remain stuck at low and not change from high to low, i.e., no falling-edge signal is generated.

[0048] More specifically, in one embodiment, when the control unit is configured such that an unexpected reset causes both the control signal and the PWM signal to go low, the trigger signal can be set to a rising edge signal. That is, the control signal is only valid when the PWM signal is a rising edge signal. When the control unit is unexpectedly reset and does not return to normal, the PWM signal may remain at a high level, may experience a falling edge (i.e., quickly change from high to low), or may remain at a low level but will not experience a rising edge (i.e., quickly change from low to high).

[0049] More specifically, in another embodiment, when the control unit is configured to trigger an unexpected reset such that both the control signal and the PWM signal go high, the trigger signal can be set to a falling edge signal. That is, the control signal is only valid when the PWM signal is a falling edge signal. When the control unit is unexpectedly reset and does not return to normal, the PWM signal may remain stuck at a low level, may have a rising edge (i.e., quickly change from low to high), or may remain at a low level but will not have a falling edge (i.e., quickly change from high to low).

[0050] In the above embodiment, the trigger chip 01 also includes a power input port VCC for connecting to a power supply, which supplies power to the trigger chip 01 through the power input port VCC. The trigger chip 01 also includes a ground port GND for grounding to ensure stable operation of the trigger chip 01.

[0051] The AND gate chip 02 also has a power input port VCC for connecting to a power source. The power source supplies power to the AND gate chip 02 through the power input port VCC. The AND gate chip 02 also has a ground port GND for grounding to ensure stable operation.

[0052] For example, when the control signal output by the control unit is high, it indicates a request to close the electronic control switch; when the control signal output by the control unit is low, it indicates a request to open the electronic control switch. The electronic control switch can be, for example, a relay, or more specifically, a high-voltage relay for controlling a high-voltage circuit.

[0053] Furthermore, in the above embodiments, when the control unit is unexpectedly reset and cannot return to normal within a preset time, the safety status signal changes from a normal status level value to an abnormal status level value.

[0054] Specifically, under normal control unit conditions, the safety status signal output by the power management chip is at a normal state level, meaning it can be initially set to the normal state level. Only when the control unit is unexpectedly reset and fails to return to normal within a preset time will the safety status signal output by the power management chip change to an abnormal state level. This method, by setting a preset time, acts as a buffer, providing the control unit with response time to restore normal operation and regain control of the electronic switch.

[0055] Unexpected resets of the control unit can be caused by program errors, I / O port malfunctions, failure to feed the watchdog timer, or other reasons, making it difficult to completely prevent such resets. Therefore, it is necessary to design a circuit so that the electronic switch is not immediately disconnected when the control unit unexpectedly resets.

[0056] The explanation for "stopping watchdog timer feeding" is as follows: In a control system, there exists a hardware timer called a watchdog timer, used to monitor the normal operation of the system. The watchdog timer is activated when the system starts. During normal system operation, the software must periodically "feed" the watchdog, i.e., reset the watchdog timer. If, for some reason (such as software failure, hardware failure, or system overload), the software fails to "feed" the watchdog in time, the watchdog timer will count to zero and time out. Once it times out, the watchdog timer will trigger a reset signal, causing the control unit in the control system to restart, which can lead to an unexpected reset of the control unit.

[0057] In the above embodiments, a delay circuit can be incorporated into the power management chip, implemented by an internal timer. This allows the power management chip to delay the transition from a safe state signal to an abnormal state level by a preset time. Using an internal timer for the delay circuit, rather than a simple RC circuit (i.e., a circuit using only a combination of resistors and capacitors), helps improve timing accuracy and allows for more precise control of the preset time.

[0058] Furthermore, in the above embodiments, when the safety status signal is at a normal state level, the PWM signal can be continuously refreshed to generate a trigger signal. When the PWM signal is a trigger signal, the control signal at the current moment is triggered, and the first control signal is the control signal at the current moment. That is, the PWM signal can only be continuously refreshed to generate a trigger signal when the safety status signal is at a normal state level, and the first control signal can only be re-determined based on the control signal output by the control unit at the current moment when the PWM signal is a trigger signal. The first control signal is consistent with the control signal output by the control unit at the current moment. For example, if the control signal output by the control unit at the current moment indicates that the electronic control switch is open, then the first control signal also indicates that the electronic control switch is open; if the control signal output by the control unit at the current moment indicates that the electronic control switch is closed, then the first control signal also indicates that the electronic control switch is closed.

[0059] When the PWM signal is not a trigger signal, the control signal at the current moment is not triggered, and the first control signal is the control signal from the previous moment. That is, even if the safety state signal is at the normal state level, the PWM signal can continuously refresh to generate a trigger signal. As long as the PWM signal is not a trigger signal at the current moment, the first control signal maintains its state from the previous moment and will not redetermine its state based on the control signal output by the control unit at the current moment.

[0060] Using the above method, the control circuit can function as a latching circuit, enabling the latching of control signals. Specifically, at a specific moment (e.g., the moment the control unit unexpectedly resets), the first control signal from the previous moment is latched at the first output port Q, achieving temporary signal storage and state maintenance. Specifically, when the control unit unexpectedly resets, it indicates an anomaly. Taking a reset mechanism where no rising edge is generated during reset as an example, the control signal output by the control unit becomes low, the PWM signal is no longer refreshed, and no trigger signal is generated. Therefore, the first control signal will maintain the state of the previous moment for a preset time, without being redefined based on the control signal output by the control unit at the current moment. Simultaneously, the safety state signal is also correspondingly delayed to an abnormal state level, preventing the electronic control switch from immediately disconnecting. In the field of electric vehicles, where the electronic control switch is a relay, especially a high-voltage relay, the above control method can prevent the immediate application of high voltage and the instantaneous power interruption when the control unit unexpectedly resets, thus improving safety and stability.

[0061] By incorporating a latch circuit into the control circuit design, a pure logic circuit can be transformed into a sequential logic circuit. That is, the control signal output by the circuit at any given time depends not only on the control signal input by the control unit at the current time, but also on the control signal input at the previous time. This avoids the electronic switch from immediately disconnecting when the control unit is accidentally reset.

[0062] The trigger signal mentioned above can be either a rising edge signal or a falling edge signal; it only needs to be a short-lived, rapidly changing signal. Once a rising edge signal is selected, it will always remain a rising edge signal and will not change to a falling edge signal during use. Similarly, once a falling edge signal is selected, it will always remain a falling edge signal and will not change to a rising edge signal during use. Using this type of trigger signal in the latch circuit design helps ensure that the signal is processed at the correct time, guaranteeing signal stability.

[0063] The flip-flop chip 01 used to implement the latch control signal function is a D flip-flop chip. A D flip-flop chip is the smallest basic unit of sequential logic circuits, and the latch circuit with the aforementioned latch signal function can be designed based on a D flip-flop chip.

[0064] Furthermore, in the above embodiments, when the safety status signal is at a normal state level, the second control signal is determined based on the first control signal. Specifically, when the safety status signal is at a normal state level, in the first case, the power management chip is functioning normally and the control unit is also in a normal state, allowing normal control of the power switch, and the second control signal can be directly determined based on the first control signal. In the second case, the control unit unexpectedly resets but is still within a preset time period, waiting for the control unit to return to normal. In this case, the first control signal can maintain the state of the previous moment, and therefore the second control signal determined based on the first control signal can also maintain the state of the previous moment, thus preventing the power switch from immediately disconnecting.

[0065] Furthermore, in the above embodiments, the normal state level is high, and the abnormal state level is low. When the safety state signal is low, the second control signal is low, and the electronic control switch is open. Specifically, when the safety state signal is low, it indicates that the control unit has experienced an unexpected reset and cannot autonomously return to normal. To prevent larger accidents or more serious damage, the second control signal goes low, controlling the electronic control switch to open.

[0066] As mentioned above, the trigger signal is either a rising edge signal or a falling edge signal. Further, in the above embodiments, taking a rising edge signal as an example, when the safety status signal is high and the PWM signal is a rising edge signal, both the first control signal and the second control signal are the same as the control signal at the current moment. When the safety status signal is high and the PWM signal is a non-rising edge signal, both the first control signal and the second control signal are the same as the control signal at the previous moment.

[0067] The following explanation, using the increment table corresponding to the control circuit for the electronically controlled switch in Figure 1, further details the implementation of the input and output embodiments of the control circuit. Taking the trigger signal as a rising edge signal as an example, Table 1 shows the increment table of the control circuit for the electronically controlled switch.

[0068] Table 1. Value-added table for control circuits used in electronic switches

[0069] In Table 1, "CP" represents the second input port CP of flip-flop chip 01, which receives the PWM signal output by the control unit. "D" represents the first input port D of flip-flop chip 01, which receives the real-time control signal output by the control unit. "A" represents the fourth input port A of logic AND gate chip 02, which receives the safety status signal output by the power management chip. "Q+1" represents the state of the output second control signal at the next moment, "Q" represents the current output state, and "Q" and "Q+1" are the relationship between the output values ​​of the sequential logic circuit. "L" represents low level, "H" represents high level, and "↑" represents rising edge. "X" indicates that regardless of whether the control signal is high or low, the output second control signal does not depend on the input control signal at this time.

[0070] When the control signal is low (L), the PWM signal is rising (↑), and the safety status signal is low (L), it indicates that although the control unit is in a normal state and there has been no unexpected reset, the power management chip has not yet entered a normal state (i.e., a normal and safe operating state). Therefore, the second control signal output at the next moment will be low (L), and the power switch will be in the off state. If the power switch is currently off, it will remain off at the next moment. If the power switch is currently closed, it will open at the next moment.

[0071] When the control signal is low (L), the PWM signal is rising (↑), and the safety status signal is high (H), it indicates that the control unit and the power management chip are in normal operation (i.e., a normal and safe working state). In this case, the second control signal output at the next moment will be low (L). If the electronic switch is currently open, it will remain open at the next moment. If the electronic switch is currently closed, the control unit can normally control the electronic switch to open at the next moment.

[0072] When the control signal is high (H), the PWM signal is rising (↑), and the safety status signal is low (L), it indicates that although the control unit is in a normal state and there has been no unexpected reset, the power management chip is malfunctioning. Therefore, the second control signal output at the next moment will be low (L). If the electronic control switch is currently open, it will remain open at the next moment. If the electronic control switch is currently closed, it will open at the next moment.

[0073] When the control signal is high (H), the PWM signal is rising (↑), and the safety status signal is high (H), it indicates that the control unit and the power management chip are in normal operation (i.e., a normal and safe working state). In this case, the second control signal output at the next moment will be high (H). If the electronic switch is currently open, the control unit can normally control the electronic switch to close at the next moment. If the electronic switch is currently closed, it can remain closed at the next moment.

[0074] When the control unit is unexpectedly reset, the PWM signal will no longer generate a rising edge (↑) and may be reset to a low level (L). Within a preset time, it waits for the control unit to return to normal. The safety state signal remains high (H), and the current state of the second control signal is Q. The state of the second control signal at the next moment will also remain Q. The electronic switch will maintain its current state at the next moment.

[0075] When the control unit is unexpectedly reset, the PWM signal will no longer generate a rising edge (↑) and may be reset to a low level (L). If the control unit cannot return to normal within a preset time, the safety status signal will become a low level (L), and the second control signal will become a low level (L) at the next moment. If the electronic control switch is currently in the open state, it will remain open at the next moment. If the electronic control switch is currently in the closed state, it will open at the next moment.

[0076] In another embodiment, taking a falling edge signal as an example, when the safety status signal is high and the PWM signal is a falling edge signal, both the first control signal and the second control signal are the same as the control signal at the current moment. When the safety status signal is high and the PWM signal is a non-falling edge signal, both the first control signal and the second control signal are the same as the control signal at the previous moment.

[0077] For example, the duty cycle of the PWM signal output by the control unit is 1-99% and the frequency is 1Hz-100kHz. More specifically, the duty cycle and frequency of the PWM signal can be selected according to the duration requirements of the preset time in the foregoing embodiments. In this embodiment, the PWM signal can be set, for example, to a duty cycle of 50% and a frequency of 1kHz.

[0078] Taking a rising edge trigger signal as an example, under normal operating conditions, the real-time control signal input to the control unit is only valid when the PWM signal is a rising edge signal. When the PWM signal is not a rising edge signal, such as a falling edge signal, or a high-level or low-level state, the real-time control signal input to the control unit is invalid. For example, a rising edge refers to the instant when the digital level changes from low (digital "0") to high (digital "1").

[0079] Taking a falling edge trigger signal as an example, under normal operating conditions, the real-time control signal input to the control unit is only valid when the PWM signal is a falling edge signal. When the PWM signal is not a falling edge signal, such as a rising edge signal, or a high-level state, or a low-level state, the real-time control signal input to the control unit is invalid. For example, a falling edge refers to the instant when the digital level changes from high (digit "1") to low (digit "0").

[0080] Furthermore, in the above embodiments, when the second control signal is high, the electronically controlled switch is closed. Correspondingly, when the second control signal is low, the electronically controlled switch is open. By setting the control method of the electronically controlled switch to be consistent with that of the control signal output by the control unit, that is, the electronically controlled switch is closed when the second control signal is high and open when the second control signal is low, the control method is simple, easy to understand, and less prone to errors.

[0081] In the above embodiments, the preset time is 1ms-2s. Specifically, the preset time can depend on the selection of the power management chip, and can be configured by setting the corresponding time register during program initialization. Specifically, it can be configured within the power management chip. The preset time can serve as a buffer time, providing a reminder. When the control unit fails to return to normal within the preset time, it can promptly control other electrical components to take corresponding measures to prevent accidents. It can also remind the user to take timely remedial measures, thereby improving safety.

[0082] In the above embodiments, the control unit can be a microcontroller, and the electronic switch can be a relay. In particular, the electronic switch can be a high-voltage relay.

[0083] By employing the control circuit for the electronically controlled switch in the above embodiments of the present invention, the unexpected closing or unintended opening of the electronically controlled switch is effectively avoided, and the delayed opening of the electronically controlled switch is effectively controlled, so that the electronically controlled switch will not be immediately opened due to accidental reset of the control unit.

[0084] Secondly, embodiments of the present invention also disclose an electric vehicle, including the control circuit for an electric control switch as described in any of the foregoing embodiments. The electric control switch is a relay. When the relay is closed, the battery pack of the electric vehicle supplies power to the motor of the electric vehicle. When the relay is open, the battery pack of the electric vehicle does not supply power to the motor of the electric vehicle.

[0085] By adopting the above technical solution, the present invention can control the validity of the real-time control signal output by the control unit through the PWM signal. When the control unit is accidentally reset, the PWM signal is no longer refreshed. The first control signal determines whether it is the control signal at the current moment or the control signal at the previous moment based on whether the current PWM signal is a trigger signal or a non-trigger signal. The safety state signal maintains the normal state level value within a preset time, thereby delaying the change of the second control signal. Therefore, within the preset time, the electronic control switch can still maintain the state of the previous moment. Thus, when the electronic control switch was originally in the closed state, it will not be immediately opened due to the accidental reset of the control unit, thereby improving the safety and stability of the entire circuit.

[0086] In particular, electric vehicles will not experience immediate power loss due to a brief accidental reset of the control unit while driving at high speeds, thus preventing dangerous situations. This helps improve the safety and stability of electric vehicle use and has very high practicality and reliability in enhancing the safety of electric vehicles.

[0087] Thirdly, referring to Figure 2, embodiments of the present invention also disclose a control method for an electrically controlled switch, wherein the electrically controlled switch is controlled using the control circuit for an electrically controlled switch described in any of the foregoing embodiments, and the control method specifically includes the following steps:

[0088] S1: Determine the real-time control signals, PWM signals, and safety status signals.

[0089] Among them, the control signal is configured as the signal that initially controls the closing or opening of the electronic control switch, the PWM signal includes a trigger signal and a non-trigger signal, and the safety status signal is configured to indicate whether the power management chip is in a normal state.

[0090] S2: Determine whether the first control signal is the control signal at the current moment or the control signal at the previous moment based on whether the current PWM signal is a trigger signal or a non-trigger signal.

[0091] S3: Determine the second control signal based on the first control signal and the safety status signal; wherein the second control signal is configured as the signal that ultimately controls the closing or opening of the electronic control switch.

[0092] S4: Control the electronic switch to close or open according to the second control signal.

[0093] Specifically, the PWM signal can be continuously refreshed to generate a trigger signal only when the safety status signal is at the normal status level. When the control unit is unexpectedly reset, the PWM signal will no longer be refreshed and will no longer generate a trigger signal. The safety status signal will maintain the normal status level for a preset time.

[0094] By adopting the above technical solution, the present invention can control the validity of the real-time control signal output by the control unit through the PWM signal. When the control unit is accidentally reset, the PWM signal is no longer refreshed. The first control signal determines whether it is the control signal at the current moment or the control signal at the previous moment based on whether the current PWM signal is a trigger signal or a non-trigger signal. The safety state signal maintains the normal state level value within a preset time, thereby delaying the change of the second control signal. Therefore, within the preset time, the electronic control switch can still maintain the state of the previous moment. Thus, when the electronic control switch was originally in the closed state, it will not be immediately opened due to the accidental reset of the control unit, thereby improving the safety and stability of the entire circuit.

[0095] While the present invention has been illustrated and described with reference to certain preferred embodiments, those skilled in the art should understand that the above description is a further detailed explanation of the invention in conjunction with specific embodiments, and should not be construed as limiting the specific implementation of the invention to these descriptions. Various changes in form and detail can be made by those skilled in the art, including several simple deductions or substitutions, without departing from the spirit and scope of the invention.

Claims

1. A control circuit for an electronically controlled switch, characterized in that, include: The trigger chip includes a first input port, a second input port, and a first output port. The first input port is configured to receive a real-time control signal from a control unit, the control signal being configured to initially control the closing or opening of the electronically controlled switch. The second input port is configured to receive a PWM signal from the control unit, the PWM signal including a trigger signal and a non-trigger signal. The first output port is configured to output a first control signal. The trigger chip is configured to determine whether the first control signal is the control signal at the current moment or the control signal at the previous moment based on whether the current PWM signal is a trigger signal or a non-trigger signal. The logic AND gate chip includes a third input port, a fourth input port, and a second output port. The third input port is configured to receive a first control signal output from the first output port of the flip-flop chip. The fourth input port is configured to receive a safety status signal from a power management chip, which is configured to indicate whether the power management chip is in a normal state. The second output port is configured to output a second control signal, which is configured to ultimately control the closing or opening of the electronic switch. Specifically, the PWM signal can be continuously refreshed to generate the trigger signal only when the safety status signal is at the normal status level. When the control unit is unexpectedly reset, the PWM signal is no longer refreshed and the trigger signal is no longer generated. The safety status signal maintains the normal status level for a preset time.

2. The control circuit for an electronically controlled switch as described in claim 1, characterized in that, When the control unit is unexpectedly reset and cannot return to normal within the preset time, the safety status signal changes from the normal status level value to the abnormal status level value.

3. The control circuit for an electronically controlled switch as described in claim 2, characterized in that, When the PWM signal is the trigger signal, the control signal at the current moment is triggered, and the first control signal is the control signal at the current moment; and / or, when the PWM signal is the non-trigger signal, the control signal at the current moment is not triggered, and the first control signal is the control signal at the previous moment.

4. The control circuit for an electronically controlled switch as described in claim 3, characterized in that, When the safety status signal is at the normal status level, the second control signal is determined according to the first control signal.

5. The control circuit for an electronically controlled switch as described in claim 4, characterized in that, The normal state level is high, the abnormal state level is low, and when the safety state signal is low, the second control signal is low and the electronic control switch is off.

6. The control circuit for an electronically controlled switch as described in claim 5, wherein the trigger signal is a rising edge signal or a falling edge signal, and when the safety state signal is high and the PWM signal is the trigger signal, the first control signal and the second control signal are the same as the control signal at the current moment, and / or, when the safety state signal is high and the PWM signal is a non-trigger signal, the first control signal and the second control signal are the same as the control signal at the previous moment.

7. The control circuit for an electronically controlled switch as described in claim 6, characterized in that, When the second control signal is high, the electronic control switch is closed.

8. The control circuit for an electronically controlled switch as described in claim 1, characterized in that, The preset time is 1ms-2s, and / or the duty cycle of the PWM signal is 1-99% and the frequency is 1Hz-100KHz, and / or the control unit is a microcontroller, and / or the trigger chip is a D trigger chip.

9. An electric vehicle, characterized in that, The device includes a control circuit for an electronically controlled switch as described in any one of claims 1-8, wherein the electronically controlled switch is a relay, and when the relay is closed, the battery pack of the electric vehicle supplies power to the motor of the electric vehicle; when the relay is open, the battery pack of the electric vehicle does not supply power to the motor of the electric vehicle.

10. A control method for an electronically controlled switch, characterized in that, The electric switch is controlled by the control method for the electric switch as described in any one of claims 1-8, the control method comprising: The system determines real-time control signals, PWM signals, and safety status signals, wherein the control signals are configured to initially control the closing or opening of the electronic control switch, the PWM signals include trigger signals and non-trigger signals, and the safety status signals are configured to indicate whether the power management chip is in a normal state. Determine whether the first control signal is the control signal of the current moment or the control signal of the previous moment based on whether the current PWM signal is a trigger signal or a non-trigger signal; A second control signal is determined based on the first control signal and the safety status signal, wherein the second control signal is configured as a signal to ultimately control the closing or opening of the electronic control switch; The electronic switch is closed or opened according to the second control signal; Specifically, the PWM signal can be continuously refreshed to generate the trigger signal only when the safety status signal is at the normal status level. When the control unit is unexpectedly reset, the PWM signal is no longer refreshed and the trigger signal is no longer generated. The safety status signal maintains the normal status level for a preset time.

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