WO2019140800A1

WO2019140800A1 - Vehicle-mounted charger wide-range duty cycle cp signal detection method based on low-power-consumption chip

Info

Publication number: WO2019140800A1
Application number: PCT/CN2018/083859
Authority: WO
Inventors: 刘钧; 冯颖盈; 姚顺; 郑必伟
Original assignee: 深圳威迈斯电源有限公司
Priority date: 2018-01-17
Filing date: 2018-04-20
Publication date: 2019-07-25
Also published as: CN108254626A

Abstract

The present invention relates to the technical field of electric vehicle charging, and discloses a vehicle-mounted charger wide-range duty cycle CP signal detection method based on a low-power-consumption chip. The method comprises the following steps: step 1, configuring a vehicle-mounted charger chip to be in a low-power-consumption working mode; step 2, configuring the chip to obtain a CP signal capturing function by means of a query mechanism; step 3, obtaining CP signal state information by using the query mechanism; step 4, determining whether to wake the vehicle-mounted charger according to the obtained CP signal state information. According to the present invention, under the condition that low-power-consumption current index requirements of the vehicle-mounted charger during the whole dormant state can be met, a wide-range duty cycle CP signal (3%-97%) can also be normally and accurately detected; moreover, the next-step charger working/dormancy state determining is performed. Therefore, international CP signal detection requirements of the vehicle-mounted charger in the whole working process are met.

Description

Wide-range duty cycle CP signal detection method for vehicle charger based on low power chip

Technical field

The invention belongs to the technical field of electric vehicle charging, and particularly relates to a wide range duty cycle CP signal detecting method for a vehicle charger based on a low power consumption chip.

Background technique

Cars provide great convenience for people, but traditional fuel vehicles generate a lot of waste gas during use, which aggravates human dependence on non-renewable petroleum resources. With the strengthening of public environmental awareness, it advocates green travel and changes the travel structure. The more it becomes the mainstream. Green travel has spawned the development of new energy vehicles, and electric vehicles are the most representative of new energy vehicles, including hybrid electric vehicles, plug-in hybrid electric vehicles and pure electric vehicles. Hybrid electric vehicles do not require additional charging equipment, and the energy energy is purely generated by the interior of the vehicle. Plug-in hybrid electric vehicles and pure electric vehicles require external charging devices, and the car charger is usually in a dormant state when not charging. When an external charging device is needed to charge a new energy vehicle, the charging device needs to wake up the car charger. There are usually three types of wake-up car chargers: the battery management unit (BMS) wakes up, the CC signal of the charging gun wakes up, and the CP signal of the charging gun wakes up. This patent provides a low-power chip for the CP signal wake-up mode of the charging gun. Wide range CP signal duty cycle detection strategy.

The CP signal usually has four states: DC 12V, DC 9V, PWM 9V, PWM 6V. The state involved in this patent is the CP signal in the PWM phase, and the frequency of the CP phase in the PWM phase is 1KHz. For the detection of the CP signal duty cycle, The national standard requirements can be accurately detected within the range of 3% to 97%. It is not required to accurately measure the duty cycle value outside this range, but it must be recognized and can stop charging.

The conventional CP signal acquisition detection method is that when the edge signal (rising edge or falling edge) of the PWM arrives, the edge signal triggers the chip capture interrupt, and the time of the rising edge or the falling edge is processed in the interrupt to obtain the corresponding frequency. And duty cycle. This method is easy to detect this wide range of duty cycle and meet the national standard requirements when the chip's main frequency is relatively high. However, since it is applied in the car, when the car charger is not charged, it is in a dormant state. At this time, it is necessary to consume the electricity of the small battery on the car. The electric car has a requirement for the power consumption of the charger in the dormant state, and usually cannot be required. More than 1mA, you can not use high frequency of the chip at this time, you need to choose a chip with low power consumption, such chips in order to reduce power consumption, low frequency mode will be adjusted at a lower frequency, if you press Conventional methods to design software can not accurately detect signals in a wide range of 3% to 97%, usually only 10% to 90%; another conventional processing method is that low-power chips do not detect CP. The air ratio, as long as the edge signal of the CP is detected, wakes up the main control chip of the latter stage, and the main control chip of the latter stage further detects the duty ratio of the CP signal, and satisfies the requirement to maintain the awake state, otherwise it is switched back. In the sleep state, this mode can meet the low power consumption current index requirement in the normal sleep state, but the charger will be awakened to the CP signal when the CP edge signal is detected or even the edge signal is detected. Detection will lead to higher power consumption charger false wake-up sessions, and can not be guaranteed low power requirements throughout the dormant stage.

The above-mentioned prior art in-vehicle charger cannot accurately detect the frequency and duty ratio of the CP signal while satisfying low power consumption, and the present invention proposes a wide range of on-board chargers based on low-power chips. Air ratio CP signal detection method.

Summary of the invention

Aiming at the problems in the prior art, the main object of the present invention is to provide a wide-range duty cycle CP signal detection method for a vehicle-mounted charger based on a low-power chip; the method can meet the low power consumption and can Accurately detecting the duty cycle of the CP signal, so that the charger can maintain a low power state during the sleep phase until the CP signal that meets the requirements is detected to wake up the charger, thereby solving the problem of wide charging in the low power sleep state of the vehicle charger The air ratio CP signal detects the wake-up problem, ensuring that the charger meets the low-power current specification requirements throughout the sleep phase, thereby achieving the above purpose.

The invention discloses a wide range duty cycle CP signal detection method for a vehicle charger based on a low power consumption chip, and the method comprises the following steps:

Step 1: Configure the on-board charger chip to operate in a low-power mode;

Step 2: Configuring the chip to acquire a capture function of the CP signal by using a query mechanism;

Step 3: Acquire the CP signal state information by using the query mechanism.

Step 4: Determine whether the in-vehicle charger performs wake-up processing according to the acquired CP signal status information.

Preferably, the step 3 specifically includes the following steps:

Step 31: The capture state register of the chip is continuously queried through an infinite loop of the t period, thereby quickly acquiring the CP signal acquisition state of the chip.

Preferably, the step 31 specifically includes the following steps:

Step 311: Determine whether the signal detected by the current state processing is a CP message; if yes, go to step 312; if not, proceed to step 311;

Step 312: Determine whether the CP edge signal is detected, if yes, go to step 313; if not, return to step 311;

Step 313: Read the CP related register of the chip, and calculate the CP signal duty cycle and period.

Preferably, after the step 313, the following steps are further performed:

Step 314: Perform low-pass filtering processing on the CP signal duty cycle and the period.

Preferably, the time period in step 31 is 100 ms.

Preferably, the step 4 specifically includes the following steps:

Step 41: Determine whether the CP signal meets the in-vehicle charger wake-up request according to the acquired CP signal state information; if yes, go to step 42, otherwise, go to step 43;

Step 42: wake up the on-board charger to enter the normal charging operation state, and then jump to step 44;

Step 43: Control the in-vehicle charger to continue to maintain the sleep state;

Step 44: The chip enters a sleep state.

Preferably, the wake-up request of the on-board charger in the step 41 is specifically: the detected CP signal is a PWM signal, and the duty ratio is 3% to 97%, and the frequency is 1 KHz.

Preferably, the time period in which the step 4 is performed is 100 ms.

Preferably, the step 3 and the step 4 respectively perform program blocking processing and alternately perform.

Preferably, the chip is TI's MSP430 series low power chip.

The technical solution of the embodiment of the invention provides a wide-range duty cycle CP signal detection method for a vehicle-mounted charger based on a low-power chip; the technical solution of the embodiment of the invention has the following remarkable effects:

This patent mainly protects a software detection and processing method, which can accurately and accurately detect a wide range of duty cycle CP signals under the condition of satisfying the low power consumption current index requirement of the on-board charger in the whole sleep state ( 3% to 97%), and carry out the next step of judging the working state of the charger to meet the requirements of the national standard for the detection of CP signals during the entire working process of the on-board charger. The advantage is that the low-power chip can accurately detect the CP signal of a wide range of duty cycles and accurately complete the operation of sleeping or waking up the charger when the power consumption requirement of the whole sleep state is satisfied.

DRAWINGS

1 is a flowchart of a method for detecting a wide-range duty cycle CP signal of a vehicle-mounted charger based on a low-power chip according to an embodiment of the present invention;

2 is a detailed flowchart of a method for detecting a wide-range duty cycle CP signal of a vehicle-mounted charger based on a low-power chip according to an embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. The embodiments are merely a part of the embodiments of the invention, and not all of the embodiments. All other embodiments obtained by a person skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

The existing conventional schemes for handling CP signal acquisition mechanisms use interrupts to process related data. This method has high real-time performance and high acquisition accuracy. This scheme is especially suitable for chips with high frequency, but in the vehicle charging gun wake-up application. Using a chip with a high frequency will result in a large power consumption in the sleep state, while a chip with a low power consumption has a low main frequency and meets the power consumption requirement, but the CP detection uses a conventional scheme to interrupt the response time and the calculation time after the interruption. It is also longer, and both will greatly affect the calculation accuracy of the duty cycle.

The patent discloses a scheme for optimizing the duty ratio of a CP signal in a wide range by satisfying a software processing method for detecting a duty ratio of a capture CP in a low-power chip, and satisfying the purpose of detecting a duty ratio of a CP signal in a wide range under the condition of low power consumption, and satisfying the national standard for the vehicle. The detection requirements of the CP signal of the charger.

As shown in FIGS. 1 and 2, the present invention discloses a wide-range duty cycle CP signal detection method for a vehicle-mounted charger based on a low-power chip, the method comprising the following steps:

Step 1: Configure the on-board charger chip to operate in a low-power mode;

Step 3: Acquire the CP signal state information by using the query mechanism.

Preferably, the step 3 specifically includes the following steps:

Preferably, the step 31 specifically includes the following steps:

Preferably, after the step 313, the following steps are further performed:

Preferably, the time period in step 31 is 100 ms.

Preferably, the step 4 specifically includes the following steps:

Step 44: The chip enters a sleep state.

Preferably, the time period in which the step 4 is performed is 100 ms.

Preferably, the chip is TI's MSP430 series low power chip.

In another preferred embodiment, the steps of use of this patent application are as follows:

Step 1: The selected CP signal detection chip needs to have a PWM signal acquisition function;

Step 2: Configure the chip to be in low-power sleep mode and wake up from pin level to enter low-power operation state;

Step 3: The PWM capture function of step 1 is not available in the conventional method. The interrupt response time affects the detection accuracy of the duty cycle. The configuration chip acquires the capture time of the CP signal through the query mechanism. The specific query mode is: through a certain time. The infinite loop of the segment continuously queries the capture state register of the chip, so as to quickly acquire the CP signal capture state of the current chip, which is equivalent to the infinite loop non-stop query mode to compensate for the shortcoming of the low-frequency chip interrupt response time.

Step 4: Step 3 adopts the query mechanism to ensure that the query interval is short enough. In order to achieve this purpose, the function is divided into blocks in the main program;

Step 5: The program block 1 in step 4 detects the CP signal for 100 ms, and the program block 2 is 100 ms to determine whether the CP is normal and wakes up. The two program blocks are alternately processed, and the chip is acquired in the infinite loop for the first 100 ms. The CP capture state, the next 100ms is not captured, but the state acquired in the previous 100ms is processed to obtain the CP frequency and duty cycle and the fault judgment processing is performed, which is equivalent to making up the low frequency chip by this alternate processing method. The interrupt will make the interrupt processing time longer. Note that this is the interrupt processing time, and the interrupt response time is in step 3. ;

Step 6: The program in step 5 parses the CP signal and needs to perform low-pass filtering processing;

Step 7: The program in step 5 blocks 2 to determine whether the CP range meets the requirements of the national standard, and performs corresponding wake-up sleep processing;

This patent mainly relates to a processing strategy of a high-energy electric vehicle's on-board charger through a low-power MCU or DSP chip for accurate detection of a wide range of duty cycle CP signals, including but not limited to pure electric vehicles or plug-in type Among the hybrid electric vehicle's in-vehicle chargers, low-power MCUs or DSP chips include, but are not limited to, TI's MSP430 series of low-power chips.

The above is only the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in Within the scope of protection of the present invention.

Claims

A method for detecting a wide range duty cycle CP signal of a vehicle charger based on a low power chip, characterized in that the method comprises the following steps:

Step 1: Configure the on-board charger chip to operate in a low-power mode;

Step 2: Configuring the chip to acquire a capture function of the CP signal by using a query mechanism;

Step 3: Acquire the CP signal state information by using the query mechanism.

Step 4: Determine whether the in-vehicle charger performs wake-up processing according to the acquired CP signal status information.
The method for detecting a wide-range duty cycle CP signal of a vehicle-mounted charger based on a low-power chip according to claim 1, wherein the step 3 specifically comprises the following steps:

Step 31: The capture state register of the chip is continuously queried through an infinite loop of the t period, thereby quickly acquiring the CP signal acquisition state of the chip.
The method of claim 2, wherein the step 31 comprises the following steps:

Step 311: Determine whether the signal detected by the current state processing is a CP message; if yes, go to step 312; if not, proceed to step 311;

Step 312: Determine whether the CP edge signal is detected, if yes, go to step 313; if not, return to step 311;

Step 313: Read the CP related register of the chip, and calculate the CP signal duty cycle and period.
The low-power chip-based on-board charger wide-range duty cycle CP signal detection method according to claim 3, wherein after the step 313, the following steps are further performed:

Step 314: Perform low-pass filtering processing on the CP signal duty cycle and the period.
The method of claim 2, wherein the step t period is 100 ms.
The low-power chip-based on-board charger wide-range duty cycle CP signal detection method according to claim 1, wherein the step 4 specifically comprises the following steps:

Step 41: Determine whether the CP signal meets the in-vehicle charger wake-up request according to the acquired CP signal state information; if yes, go to step 42, otherwise, go to step 43;

Step 42: wake up the on-board charger to enter the normal charging operation state, and then jump to step 44;

Step 43: Control the in-vehicle charger to continue to maintain the sleep state;

Step 44: The chip enters a sleep state.
The method for detecting a wide-range duty cycle CP signal of a vehicle-mounted charger based on a low-power chip according to claim 6, wherein the wake-up request of the on-board charger in the step 41 is specifically: the detected CP signal is a PWM signal. The duty ratio is 3% to 97%, and the frequency is 1 kHz.
The low-power chip-based on-board charger wide-range duty cycle CP signal detection method according to claim 1, wherein the step 4 is performed for a period of 100 ms.
The method for detecting a wide-range duty-cycle CP signal of a vehicle-mounted charger based on a low-power chip according to any one of claims 1 to 8, wherein the step 3 and the step 4 respectively perform program block processing. And alternate.
The low-power chip-based on-board charger wide-range duty cycle CP signal detecting method according to any one of claims 1-8, wherein the chip is TI's MSP430 series low-power chip.