CP signal adaptation device and method for electric vehicle charging system

Abstract

The present invention provides a CP signal adaptation device for an electric vehicle charging system, comprising: a sampling unit for acquiring a CP signal; a control unit for judging the working state of the electric vehicle charging system according to the CP signal transmitted from the sampling unit and generating a first control signal; an output unit for generating and outputting a new CP signal using the first control signal transmitted from the control unit. When the amplitude of the CP signal is within the working threshold range corresponding to the working state, the first control signal is used to dynamically modulate the amplitude of the new CP signal to make it reach the desired standard range. The present invention also provides a corresponding method.

Description

Technical Field

[0001] The present invention relates to the field of electric vehicles, and in particular to a CP signal adaptation device and method for an electric vehicle charging system. Background Art

[0002] In recent years, with the development of the electric vehicle industry, electric vehicle charging systems have also been widely used.

[0003] During the period when the charging system is charging the vehicle, as the charging pile is connected to the charging system on the vehicle side, the charging system on the vehicle side needs to determine whether the voltage of the control guidance function signal (CP signal) reaches a specific limit to determine and adjust the working state. However, in actual applications, due to the wide range of electric vehicle models on the market, the production standards they are based on are not exactly the same, and after long-term use, the performance of the charging system on the vehicle side may change. Therefore, after the working state is converted, the voltage amplitude of the CP signal detected on the vehicle side may not meet the limit, so that normal charging cannot be performed.

[0004] The existing technology designs an additional DC power supply in the hardware circuit of the charging system to switch and output two different CP signal voltage amplitudes, thereby adapting to the vehicle side. However, these methods require an additional voltage source to be configured for the charging system on the charging pile side, and have poor CP signal adjustment ability and anti-interference ability, which seriously limits the adaptability of the charging system and makes the charging process unstable.

[0005] Therefore, there is an urgent need for a new technology that can dynamically adjust the CP signal and has strong anti-interference ability to adapt the CP signal of the electric vehicle charging system. Summary of the invention

[0006] The present invention aims to overcome the above and / or other problems in the prior art. The CP signal adaptation device and method for an electric vehicle charging system provided by the present invention can output an accurate and stable CP signal while being less susceptible to interference, thereby achieving a stable charging process.

[0007] According to one aspect of the present invention, a CP signal adaptation device for an electric vehicle charging system is provided, the device comprising a sampling unit, a control unit and an output unit. The sampling unit is used to obtain the CP signal of the electric vehicle charging system. The control unit determines the working state of the electric vehicle charging system according to the CP signal transmitted from the sampling unit, and generates a first control signal. The output unit uses the first control signal transmitted from the control unit to generate and output a new CP signal. When the amplitude of the CP signal is within the working threshold range corresponding to the working state, the first control signal is used to dynamically modulate the amplitude of the new CP signal to make it reach the desired standard range.

[0008] According to a second aspect of the present invention, a CP signal adaptation method for an electric vehicle charging system is provided, comprising the following steps: detecting the amplitude of the CP signal at a current moment, and judging the working state of the electric vehicle charging system accordingly; when the working state is a plug-in state or a charging state, comparing the amplitude of the CP signal with a working threshold range of the plug-in state or the charging state; when the amplitude of the CP signal is within the working threshold range, modulating the amplitude of a new CP signal with a first control signal, thereby dynamically modulating the amplitude to a desired standard value.

[0009] The CP signal adaptation device and method of the present invention detects the current CP signal amplitude and dynamically modulates the CP signal amplitude to a corresponding standard value or a value close to the standard value according to the working state, so that even if the allowable amplitude range on the vehicle side is small, the obtained CP signal can still meet the allowable amplitude requirement of the small range. In addition, by modulating the CP signal amplitude in a dynamic manner, adaptation to all vehicle models can be achieved, and dynamic modulation can also filter out various interferences in the system, thereby achieving a stable and complete charging process.

[0010] Preferably, in the CP signal adaptation device and method of the present invention, the first control signal can be generated by dynamically adjusting the duty cycle of the PWM waveform according to the working state and the amplitude of the CP signal to dynamically modulate the amplitude of the new CP signal. In the dynamic adjustment, a PID algorithm can be used as a dynamic adjustment algorithm.

[0011] Preferably, when the amplitude of the CP signal exceeds the working threshold range corresponding to the working state, it can be determined that the charging system is in an abnormal state, and a corresponding processing flow can be taken for the abnormal state.

[0012] Preferably, the working state may at least include: an unconnected state, a gun-inserted state and a charging state.

[0013] Preferably, the frequency of the first control signal may be 25 kHz, thereby making the frequency of the first control signal outside the range perceptible to the human ear and easy to filter.

[0014] According to a third aspect of the present invention, there is further provided a computer-readable storage medium on which instructions are stored, and when the instructions are executed, the CP signal adaptation method according to the present invention as described above is implemented. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention may be better understood by describing exemplary embodiments of the present invention in conjunction with the accompanying drawings, in which:

[0016] Figure 1A block diagram of a CP signal adaptation device according to the present invention is shown;

[0017] Figure 2 An exemplary circuit diagram of a CP signal amplitude source generating circuit in an output unit of a CP signal adapting device according to the present invention is shown;

[0018] Figure 3 An exemplary circuit diagram showing a CP signal generating circuit in an output unit of a CP signal adapting device according to the present invention;

[0019] Figure 4 The control guide circuit schematic diagram of the electric vehicle charging system according to charging mode 3 connection mode C in GB / T 18487.1-2015 is shown; and

[0020] Figure 5 A flow chart of a CP signal adaptation method for an electric vehicle charging system according to the present invention is shown. DETAILED DESCRIPTION

[0021] The present application will be further described below in conjunction with specific embodiments and drawings. More details are elaborated in the following description to facilitate a full understanding of the present application. However, the present application can obviously be implemented in a variety of other ways different from this description. Those skilled in the art can make similar generalizations and deductions based on actual application situations without violating the spirit of the present application. Therefore, the scope of protection of the present application should not be limited by the content of this specific embodiment.

[0022] Unless otherwise defined, the technical or scientific terms used in the claims and the specification shall have the usual meaning understood by persons with ordinary skills in the technical field to which the present application belongs. The words "first", "second" and similar words used in the specification and claims of the present application do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "one" or "a" do not indicate a quantitative limitation, but rather indicate the presence of at least one. Words such as "include" or "comprise" and similar words mean that the elements or objects appearing before "include" or "comprises" cover the elements or objects listed after "include" or "comprises" and their equivalent elements, and do not exclude other elements or objects.

[0023] According to an embodiment of the present invention, a CP signal adaptation device for an electric vehicle charging system is provided.

[0024] Reference Figure 1, which schematically shows a block diagram of a CP signal adaptation device 100 according to the present invention. The CP signal adaptation device 100 includes a sampling unit 110, a control unit 120 and an output unit 130. The sampling unit 110 is used to sample the CP signal in the charging system, so as to obtain the amplitude of the current CP signal without affecting the CP signal, and transmit it to the control unit 120. The control unit 120 determines the working state of the charging system according to the current CP signal given by the sampling unit 110, and generates a first control signal accordingly and transmits it to the output unit 130. The output unit 130 uses the first control signal to generate and output a new CP signal.

[0025] Specifically, the control unit 120 can estimate the current working state of the charging system by combining the current CP signal amplitude with the previous working state of the charging system, and determine the working threshold range that the CP signal amplitude should be in at this time according to the current working state of the charging system. When the current CP signal amplitude is within the working threshold range, this indicates that the current CP signal is normal, and the control unit 120 generates a first control signal for dynamically modulating the amplitude of the new CP signal so that the amplitude of the new CP signal gradually reaches the expected standard range. In an embodiment, the expected standard range may be stricter than the working threshold range. In an embodiment, the expected standard range may also be a single standard value. It should be noted that when the amplitude of the CP signal is mentioned in this article, it refers to the positive amplitude of the CP signal.

[0026] The working threshold range is used to determine whether the CP signal is within the normal working range corresponding to the working state, and the working threshold range can be set according to the actual situation. The expected standard range or standard value is the expected CP signal amplitude range, and it is expected that within this range, the vehicle-side charging system will definitely be able to pass the judgment of the CP signal. For example, the standard range or standard value can be the nominal value corresponding to the working state or the range close to the nominal value. In one embodiment, in the plug-in state, the working threshold range can be, for example, within (9±1.8)V, or, for example, within (9±1.5)V, and the expected standard range can be, for example, within (9±0.2)V or 9V. In one embodiment, in the charging state, the working threshold range can be, for example, within (6±1.8)V, or, for example, within (6±1.5)V, and the expected standard range can be, for example, within (6±0.2)V or 6V.

[0027] During the charging process, as the working state changes, the amplitude of the CP signal will also change accordingly, and the charging pile side and the vehicle side detect the amplitude of the CP signal (for example, as described below). Figure 4As shown, the charging pile side detects the CP signal at detection point 1, and the vehicle side detects the CP signal at detection point 2) to determine whether the current working state is normal.

[0028] In the prior art, in order to adjust the amplitude of the CP signal, two different amplitudes (for example, two amplitudes with a difference of 1V from each other) are often provided, and then the adjustment is performed by switching between the two different amplitudes. The flexibility of this adjustment method is very poor, and the amplitude of the adjusted CP signal has a fixed difference with the amplitude of the initial CP signal, so it is basically impossible to make the amplitude of the CP signal reach the nominal value. In the CP signal adaptation device of the present invention, the amplitude of the CP signal can be gradually changed by dynamic modulation without being restricted by the amplitude of the initial CP signal, thereby achieving adaptation to all vehicle models at the same time. Through dynamic modulation, the amplitude of the CP signal can be changed to the desired standard range or standard value, thereby ensuring that the vehicle side can always pass the judgment of the CP signal. In addition, due to the progressive nature of dynamic modulation, the interference to the CP signal during this period can also be well filtered out, which makes the charging process more stable.

[0029] Optionally, the control unit 120 may generate the first control signal by dynamically adjusting the duty cycle of the PWM waveform according to the current working state and the amplitude of the CP signal, which will be described in detail below. For example, a dynamic adjustment algorithm may be used to perform the dynamic adjustment, so that the amplitude of the CP signal can be dynamically modulated more conveniently. The dynamic adjustment algorithm may be any dynamic adjustment algorithm well known to those skilled in the art, such as a PID algorithm.

[0030] Optionally, when the current CP signal amplitude exceeds the working threshold range corresponding to the working state, this indicates that the current CP signal is abnormal, that is, it can be determined that the charging system is in an abnormal state, and the control unit 120 can respond according to the abnormal response logic (for example, as specified in GB / T 18487.1-2015). In one embodiment, for example, when the working state is the charging state and the current CP signal amplitude is 3V, it can be determined that a CP short circuit abnormality occurs and enters an abnormal state. At this time, charging can be stopped and the modulation of the CP signal amplitude (that is, the first control signal with a full duty cycle is output) can be stopped.

[0031] Optionally, the working state may include at least an unconnected state, a plugged-in state, and a charging state. In an embodiment according to GB / T18487.1-2015, in the unconnected state (also referred to as state 1), the nominal value of the CP signal amplitude is 12V; in the plugged-in state (also referred to as the connected state or state 2), the nominal value of the CP signal amplitude is 9V; in the charging state (also referred to as state 3), the nominal value of the CP signal amplitude is 6V.

[0032] Optionally, the frequency of the first control signal may be 25 kHz. Since the human hearing range is usually between 20 and 20,000 Hz, the use of a frequency of 25 kHz can avoid acoustic interference to humans. In addition, a frequency of 25 kHz is also conducive to filtering processing.

[0033] Now go to Figure 2 , Figure 2 An exemplary circuit diagram of a CP signal amplitude source generating circuit in an output unit of a CP signal adapting device according to the present invention is shown. The CP signal amplitude source generated by the circuit can be used to directly replace the 12V amplitude source in the prior art.

[0034] Reference Figure 2 , the CP signal amplitude source generating circuit includes two inputs: 12V power supply (i.e., the original 12V amplitude source) and IO1_CP_Adj (i.e., the first control signal); and one output: CP+_USE (i.e., the CP signal amplitude source generated by the circuit); wherein CP+_Adj is only used to indicate the signal at the node, and does not represent the input or output. The amplitude of CP+_USE can be controlled by IO1_CP_Adj through PWM, and the specific principle is as follows: the PWM control of IO1_CP_Adj will cause the corresponding switch of the NMOS of Q1, so that the G pole level of Q2 will produce corresponding high and low changes, thereby realizing the connection and disconnection of the 12V power supply and CP+_Adj, and this connection and disconnection makes CP+_Adj generate a waveform with an amplitude of 12V and a duty cycle the same as IO1_CP_Adj; then, through the Π-type filter circuit composed of C1, C2 and R3, the high and low changing waveform at CP+_Adj is converted into a voltage level CP+_USE with a stable voltage value as the CP signal amplitude source. As described above, it is easy to understand that the voltage value will be within the range of 0-12V depending on the duty cycle of the first control signal. For example, if the duty cycle is 100% (full duty cycle), CP+_USE=12V, which is equivalent to the original 12V power supply; if the duty cycle is 70%, CP+_USE=8.4V, and so on. Therefore, the CP signal amplitude source generating circuit of the present invention can be used to modulate the CP signal amplitude source according to the first control signal.

[0035] Using a modulated CP signal amplitude source, one can use Figure 3 The CP signal generating circuit shown is used to finally generate a new CP signal, where CP+_USE comes from the CP signal amplitude source generating circuit described above, the -12V power supply can be generated by flipping the 12V power supply, and OUT_S is used to superimpose the PWM waveform in the CP signal as needed. The amplitude of the generated CP signal will have a change trend corresponding to CP+_USE. By continuously performing dynamic modulation in this way, the CP signal amplitude can be gradually modulated to the desired standard range or standard value.

[0036] In an example of the CP signal amplitude source generating circuit, the capacitance and resistance values ​​can be: C1 = 2.2 μf; C2 = 0.47 μf; R1 = 0.1Ω; R2 = R4 = R6 = 1 kΩ; R3 = 10Ω; R5 = 10 kΩ. However, it should be noted that other designs are also possible and are also included in the scope of the present invention.

[0037] Next, combine Figure 4 An application example of the CP signal adaptation device of the present invention is described.

[0038] Figure 4 This is the control and guidance circuit schematic diagram of the electric vehicle charging system according to charging mode 3 connection method C in GB / T 18487.1-2015. Figure 4 As shown, the CP signal is transmitted on the line at the bottom of the figure. At detection point 1, the sampling unit samples the CP signal. When the amplitude of the CP signal changes from 12V to 9.8V, the control unit can determine that the system state is converted from the unconnected state to the plugged-in state. Although in theory, the acceptable CP signal amplitude on the vehicle side in the plugged-in state can fluctuate by 0.8V above and below the nominal value of 9V, due to issues such as vehicle model and loss, even when the CP signal amplitude is 9.8V, the vehicle side may determine it as not meeting the requirements (i.e., abnormal state), and then stop charging. Here, the expected standard range in the plugged-in state can be set to (9±0.1)V, and the vehicle side must be able to determine that the CP signal amplitude within this standard range is passed. The control unit can first determine that the current amplitude (9.8V) is within the working threshold range of the plugged-in state (e.g., (9±1.5)V), and then output a first control signal that dynamically reduces the CP signal amplitude to (9±0.1)V. As a result, the CP signal amplitude will quickly approach (9±0.1)V, ensuring that the vehicle side also determines that the CP signal meets the requirements of the gun insertion state.

[0039] In addition, in order to make the upper limit of the adjustable amplitude larger, the Figure 4 In one embodiment, R1 can be set to 680Ω.

[0040] According to an embodiment of the present invention, a CP signal adaptation method for an electric vehicle charging system is also provided accordingly.

[0041] Reference Figure 5 , which shows a flow chart of a CP signal adaptation method 500 for an electric vehicle charging system according to the present invention. The method 500 may include steps 510 to 540.

[0042] In step 510, the amplitude of the CP signal at the current moment is detected, and the working state of the electric vehicle charging system is determined accordingly.

[0043] In step 520, when the working state is the plugged-in state or the charging state, the amplitude of the CP signal is compared with the working threshold range of the plugged-in state or the charging state. When the working state is other states, the amplitude of the CP signal does not need to be modulated, and the first control signal with full duty cycle is output.

[0044] In step 530, when the amplitude of the CP signal is within the working threshold range, the amplitude of the new CP signal is modulated by the first control signal, so that the amplitude is dynamically modulated to the desired standard value. When the amplitude of the CP signal exceeds the working threshold range, it is determined to be an abnormal state, and the CP signal amplitude does not need to be modulated, and the first control signal with a full duty cycle is output.

[0045] Optionally, the first control signal may be generated by dynamically adjusting the duty cycle of the PWM waveform according to the current working state and the amplitude of the CP signal. For example, a dynamic adjustment algorithm may be used to perform the dynamic adjustment, and the dynamic adjustment algorithm may be any dynamic adjustment algorithm well known to those skilled in the art, such as a PID algorithm.

[0046] Optionally, when the current CP signal amplitude exceeds the working threshold range corresponding to the working state, it can be determined that the charging system is in an abnormal state and an abnormal response is performed.

[0047] Optionally, the frequency of the first control signal may be 25 kHz.

[0048] The CP signal adaptation method 500 corresponds to the CP signal adaptation device according to the present invention. Many design concepts and details applicable to the CP signal adaptation device of the present invention are also applicable to the CP signal adaptation method 500, and the same beneficial technical effects can be obtained, which will not be repeated here.

[0049] According to an embodiment of the present invention, there is also provided a computer-readable storage medium having encoded instructions recorded thereon, which can implement the above-mentioned CP signal adaptation method for an electric vehicle charging system when the instructions are executed. The computer-readable storage medium may include a hard disk drive, a floppy disk drive, a compact disk read / write (CD-R / W) drive, a digital versatile disk (DVD) drive, a flash drive and / or a solid-state storage device, etc.

[0050] Various aspects of the present invention have been described above through some exemplary embodiments. However, it should be understood that various modifications may be made to the above exemplary embodiments without departing from the spirit and scope of the present invention. For example, if the described techniques are performed in a different order and / or if the components in the described system, architecture, device or circuit are combined in different ways and / or replaced or supplemented by other components or their equivalents, suitable results may be achieved, and accordingly, these modified other embodiments also fall within the scope of protection of the claims.

Claims

1. A CP signal adapter for an electric vehicle charging system, comprising: A sampling unit, used for acquiring a CP signal; A control unit, which determines the working state of the electric vehicle charging system according to the CP signal transmitted from the sampling unit, and generates a first control signal; an output unit, generating and outputting a new CP signal using the first control signal transmitted from the control unit, When the amplitude of the CP signal is within the working threshold range corresponding to the working state, the first control signal is used to dynamically modulate the amplitude of the new CP signal to make it reach a desired standard range.

2. The CP signal adaptation device according to claim 1, characterized in that: The control unit generates the first control signal by dynamically adjusting the duty cycle of the PWM waveform according to the working state and the amplitude of the CP signal.

3. The CP signal adaptation device according to claim 2, characterized in that: The PID algorithm is used as the dynamic adjustment algorithm in the dynamic adjustment.

4. The CP signal adaptation device according to claim 1, characterized in that: When the amplitude of the CP signal exceeds the working threshold range corresponding to the working state, it is determined to be an abnormal state.

5. The CP signal adaptation device according to claim 1, characterized in that: The working state at least includes: an unconnected state, a gun plugged state and a charging state.

6. The CP signal adaptation device according to any one of claims 1 to 5, characterized in that: The frequency of the first control signal is 25 kHz.

7. A CP signal adaptation method for an electric vehicle charging system, comprising the following steps: Detecting the amplitude of the CP signal at the current moment, and judging the working state of the electric vehicle charging system therefrom; When the working state is a gun-plugged state or a charging state, comparing the amplitude of the CP signal with the working threshold range of the gun-plugged state or the charging state; and When the amplitude of the CP signal is within the working threshold range, the amplitude of the new CP signal is modulated by the first control signal, so as to dynamically modulate the amplitude to a desired standard value.

8. The CP signal adaptation method according to claim 7, characterized in that: The first control signal is generated by dynamically adjusting the duty cycle of the PWM waveform according to the working state and the amplitude of the CP signal.

9. The CP signal adaptation method according to claim 8, characterized in that: The PID algorithm is used as the dynamic adjustment algorithm in the dynamic adjustment.

10. The CP signal adaptation method according to claim 7, characterized in that: When the amplitude of the CP signal exceeds the working threshold range corresponding to the working state, it is determined to be an abnormal state.

11. The CP signal adaptation method according to any one of claims 7 to 10, characterized in that: The frequency of the first control signal is 25 kHz.

12. A computer-readable storage medium having instructions stored thereon, which implement the method according to any one of claims 7 to 11 when the instructions are executed.

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