阅读说明：本技术 一种电动汽车交流充电系统的cp信号电压检测方法及装置 (CP signal voltage detection method and device of electric vehicle alternating current charging system ) 是由 王君龙 翟西斌 于治楼 于 2019-09-10 设计创作，主要内容包括：本发明公开了一种电动汽车交流充电系统的CP信号电压检测方法及装置,属于电动汽车充电技术领域。本发明的电动汽车交流充电系统的CP信号电压检测方法包括以下步骤：S1、电压比较：CP信号电压值分别与设定电压值作比较,通过比较两者电压值的大小输出高电平或低电平；S2、隔离输出：步骤S1输出的高电平或低电平经过光耦转换为CMOS电平信号,并分别输入MCU的引脚；S3、采样计算：通过MCU读取引脚电平状态,查询得到当前电压值。该发明的电动汽车交流充电系统的CP信号电压检测方法简单易实现、应用场景广泛,同时能提高交流充电桩控制引导功能可靠性,同时降低成本,具有很好的推广应用价值。(The invention discloses a CP signal voltage detection method and device of an electric automobile alternating current charging system, and belongs to the technical field of electric automobile charging. The CP signal voltage detection method of the electric vehicle alternating current charging system comprises the following steps: s1, voltage comparison: the CP signal voltage value is compared with the set voltage value respectively, and high level or low level is output by comparing the voltage values of the CP signal voltage value and the set voltage value; s2, isolating output: the high level or the low level output by the step S1 is converted into a CMOS level signal by an opto-coupler and is input to pins of the MCU respectively; s3, sampling calculation: and reading the level state of the pin through the MCU, and inquiring to obtain the current voltage value. The CP signal voltage detection method of the alternating current charging system of the electric automobile is simple and easy to implement, wide in application scene, capable of improving the reliability of the control and guide function of the alternating current charging pile, capable of reducing the cost and good in popularization and application value.)

1. A CP signal voltage detection method of an electric vehicle alternating current charging system is characterized in that: the method specifically comprises the following steps:

S1, voltage comparison: the CP signal voltage value is compared with the set voltage value respectively, and high level or low level is output by comparing the voltage values of the CP signal voltage value and the set voltage value;

S2, isolating output: the high level or the low level output by the step S1 is converted into a CMOS level signal by an opto-coupler and is input to pins of the MCU respectively;

S3, sampling calculation: and reading the level state of the pin through the MCU, and inquiring to obtain the current voltage value.

2. the CP signal voltage detection method of an electric vehicle ac charging system according to claim 1, wherein: in step S1, the voltage values are set to +2.5V, +6.5V, +10V, and if the CP signal voltage value is greater than the above-mentioned constant voltage values +2.5V, +6.5V, +10V, a high level of +15V is outputted, otherwise a low level of 0V is outputted, and three level values are obtained.

3. the CP signal voltage detection method of an electric vehicle ac charging system according to claim 2, wherein: the three level values are converted into three CMOS level signals through an optical coupler, and the three CMOS level signals are input into three pins of the MCU.

4. The CP signal voltage detection method of an electric vehicle AC charging system according to claim 3, characterized in that: the sampling calculation in step S3 includes: 1) configuring the states of three pins of the MCU as input states; 2) regularly reading the input level states of the three pins; 3) filtering the invalid level state; 4) and judging the voltage value of the CP signal according to the level value combination.

5. the CP signal voltage detection method of an electric vehicle AC charging system according to claim 4, characterized in that: when the input level states of the three pins are read regularly, the input level states are recorded as 1 when the pin level is high and recorded as 0 when the pin level is low.

6. the CP signal voltage detection method of an electric vehicle AC charging system according to claim 5, characterized in that: the filtering invalid level state is that the MCU continuously reads three pin levels at a certain frequency, and if the three pin levels are all low, the three pin levels are invalid levels, the filtering invalid levels are filtered.

7. The CP signal voltage detection method of an electric vehicle AC charging system according to claim 6, characterized in that: while filtering the inactive levels, three pin levels are read every 500 us.

8. The utility model provides a CP signal voltage detection device of electric automobile alternating current charging system which characterized in that: the system comprises the following modules:

A voltage comparison module: the device is responsible for comparing the CP signal voltage value with a set voltage value and outputting a high level or a low level by comparing the magnitude of the two voltage values;

An isolation output module: the power supply is responsible for converting a high level or a low level output by the voltage comparison module into a CMOS level signal and respectively inputting the CMOS level signal into pins of the sampling calculation module;

A sampling calculation module: and the device is responsible for inquiring and obtaining the current voltage value by reading the level state of the pin.

9. The CP signal voltage detection apparatus for an ac charging system of an electric vehicle according to claim 8, wherein: the voltage comparison module is composed of three comparators, the set voltage values are +2.5V, +6.5V and +10V, and the three comparators are used for comparing respectively, when the CP signal voltage value is larger than the fixed voltage values +2.5V, +6.5V and +10V, a high level +15V is output, otherwise, a low level 0V is output, and three level values are obtained.

10. The CP signal voltage detection apparatus for an ac charging system of an electric vehicle according to claim 9, wherein: the isolation output module is three optocouplers, the sampling calculation module is an MCU, the three level values are converted into three CMOS level signals through the optocouplers, and the three CMOS level signals are input into three pins of the MCU.

Technical Field

The invention relates to the technical field of electric vehicle charging, and particularly provides a CP signal voltage detection method and device of an electric vehicle alternating current charging system.

background

The charging technology of the electric vehicle is divided into direct current charging and alternating current charging. Alternating-current charging stake compares direct-current charging stake and has certain advantage on volume, cost and installation condition.

And the CP is in full charge control guidance and is used for monitoring the interaction function between the charging pile and the electric automobile. There are four modes according to the location of CP signal generation and detection. The mode that fills electric pile wide adoption at present is three, fills electric pile and provides and produce and detect CP signal promptly, discernment and control charged state.

According to the cable that charges with fill electric pile or electric automobile's connected state, divide into three kinds of connected modes of A B C, the connected mode C that at present extensively adopts, the cable that charges is fixed promptly and links to each other with filling electric pile, links to each other with electric automobile through charging plug, under this kind of connected mode, needs to fill electric pile and pass through CP signal judgement charging plug's state such as insert and extract.

The CP signal is divided into 2 states of DC output and PWM output, where the PWM period is 1 khz. There are 3 states 12V, 9V, 6V depending on the voltage class. The charging plug is not plugged into the socket of the electric automobile, the charging plug is plugged into the socket of the electric automobile, and the electric automobile is ready and requests three states of alternating current output. The charging pile needs to identify the voltage state of the CP signal to judge the state of the charging behavior.

the current CP signal voltage detection usually adopts an analog-to-digital conversion method. The method is divided into two modes of an external AD chip and a built-in AD mode by using the MCU. The external AD chip has the defects of complex isolation circuit, high cost and the like, and the MCU built-in AD has the defects of poor precision, weak anti-interference capability and the like.

disclosure of Invention

the invention aims at solving the problems and provides a CP signal voltage detection method of an electric vehicle alternating current charging system, which is simple and easy to implement, has wide application scenes, can improve the reliability of the control and guidance function of an alternating current charging pile and can reduce the cost.

The invention further aims to provide a CP signal voltage detection device of the alternating current charging system of the electric automobile.

in order to achieve the purpose, the invention provides the following technical scheme:

A CP signal voltage detection method of an electric vehicle alternating current charging system specifically comprises the following steps:

s1, voltage comparison: the CP signal voltage value is compared with the set voltage value respectively, and high level or low level is output by comparing the voltage values of the CP signal voltage value and the set voltage value;

S2, isolating output: the high level or the low level output by the step S1 is converted into a CMOS level signal by an opto-coupler and is input to pins of the MCU respectively;

s3, sampling calculation: and reading the level state of the pin through the MCU, and inquiring to obtain the current voltage value.

Preferably, in step S1, the voltage values are set to +2.5V, +6.5V, +10V, and when the CP signal voltage value is greater than the above-mentioned constant voltage values +2.5V, +6.5V, +10V, a high level of +15V is output, otherwise a low level of 0V is output, and three level values are obtained.

Preferably, the three level values are converted into three CMOS level signals through an optical coupler, and the three CMOS level signals are input into three pins of the MCU.

Preferably, the sampling calculation in step S3 includes: 1) configuring the states of three pins of the MCU as input states; 2) regularly reading the input level states of the three pins; 3) filtering the invalid level state; 4) and judging the voltage value of the CP signal according to the level value combination.

Preferably, the three-pin input level state is read at regular time intervals, and is recorded as 1 when the pin level is high and as 0 when the pin level is low.

Preferably, the filtering invalid level state is that the MCU continuously reads three pin levels at a certain frequency, and if all the three pin levels are low, the filtering invalid level is an invalid level.

Preferably, when filtering the inactive level, three pin levels are read every 500 us.

A CP signal voltage detection device of an electric vehicle alternating current charging system comprises the following modules:

A voltage comparison module: the device is responsible for comparing the CP signal voltage value with a set voltage value and outputting a high level or a low level by comparing the magnitude of the two voltage values;

An isolation output module: the power supply is responsible for converting a high level or a low level output by the voltage comparison module into a CMOS level signal and respectively inputting the CMOS level signal into pins of the sampling calculation module;

A sampling calculation module: and the device is responsible for inquiring and obtaining the current voltage value by reading the level state of the pin.

Preferably, the voltage comparing module is composed of three comparators, the set voltage values are +2.5V, +6.5V, +10V, and the three comparators compare with each other, and when the CP signal voltage value is greater than the set voltage values +2.5V, +6.5V, +10V, a high level +15V is output, otherwise, a low level 0V is output, and three level values are obtained.

Preferably, the isolation output module is three optocouplers, the sampling calculation module is an MCU, the three level values are converted into three CMOS level signals through the optocouplers, and the three CMOS level signals are input to three pins of the MCU.

wherein, the MCU sampling calculation process includes:

1) Configuring the states of three pins of the MCU as input states;

2) Regularly reading the input level states of the three pins, and when the input level states of the three pins are regularly read, recording the input level states as 1 when the pin level is high, and recording the input level states as 0 when the pin level is low;

3) Filtering an invalid level state, wherein the MCU continuously reads three pin levels every 500us, and if the three pin levels are all low, the three pin levels are invalid levels, filtering the invalid levels;

4) And judging the voltage value of the CP signal according to the level value combination.

Compared with the prior art, the CP signal voltage detection method of the electric vehicle alternating current charging system has the following outstanding beneficial effects: the CP signal voltage detection method of the electric vehicle alternating current charging system is simple and easy to implement, can improve the reliability of the control and guide function of the alternating current charging pile, reduces the cost, has wide application scenes, and has good popularization and application values.

Drawings

FIG. 1 is a flow chart of a CP signal voltage detection method of an AC charging system of an electric vehicle according to the present invention;

Fig. 2 is a topological diagram of a CP signal voltage detection device of the ac charging system of the electric vehicle according to the present invention.

Detailed Description

The CP signal voltage detection method and apparatus of the ac charging system for an electric vehicle according to the present invention will be described in detail with reference to the accompanying drawings and embodiments.