阅读说明：本技术 一种充电桩内部温度控制方法 (Charging pile internal temperature control method ) 是由 周立平 刘晓飞 于 2019-10-18 设计创作，主要内容包括：本发明提供一种充电桩内部温度控制方法,AD采样温度算法,基准电压由电路设定,采样的电压；AD采样温度误差校准算法,因电路出现干扰,焊接方式等产生的误差,需要对采样公式进行校准,校准方式为固定点采样,计算一次方程式的K、B值进行校准；采样100次取中间值方法。温度过温安全控制,当温度到达告警温度,降低充电桩输出功率,减小发热量,防止充电桩内部温度继续上升,如果温度继续上升,继续降低充电桩输出功率,减小发热量,如果温度达到告警温度,停止充电,记录温度告警信息。(The invention provides a charging pile internal temperature control method, which comprises the following steps that an AD sampling temperature algorithm is adopted, reference voltage is set by a circuit, and sampled voltage is adopted; according to the AD sampling temperature error calibration algorithm, due to errors caused by circuit interference, welding modes and the like, a sampling formula needs to be calibrated, the calibration mode is fixed point sampling, and K, B values of a primary equation are calculated for calibration; sampling 100 times and taking the median. Temperature excess temperature safety control, when the temperature reachs warning temperature, reduce and fill electric pile output, reduce calorific capacity, prevent to fill electric pile inside temperature and continue to rise, if the temperature continues to rise, continue to reduce and fill electric pile output, reduce calorific capacity, if the temperature reaches warning temperature, stop charging, record temperature warning message.)

1. A method for controlling the internal temperature of a charging pile is characterized in that a PT1000 temperature measuring resistor is adopted in the charging pile, and an AD converter is used for accurately acquiring data; the method is characterized in that: the method comprises the following steps:

step 1, sampling PT1000 temperature measuring resistor output and then performing AD conversion;

step 2, judging whether the measuring times reach the set times or not; if the set times are reached, turning to the step 3, otherwise, turning to the step 1;

step 3, sequencing the measurement data with set times, taking an intermediate value, and resetting the measurement times;

step 4, judging whether the temperature is normal, if so, turning to the step 1, otherwise, turning to the step 5;

step 5, judging whether the temperature is over-temperature alarm or over-temperature fault, if so, turning to step 6, and if so, turning to step 7;

step 6, reducing power output, and turning to the step 1;

and 7, stopping output and reporting the temperature fault.

2. The charging pile internal temperature control method according to claim 1, characterized in that: the set number of times in step 2 is 100.

3. The charging pile internal temperature control method according to claim 1, characterized in that: in step 6, an over-temperature alarm is also sent out while the power output is reduced.

4. The charging pile internal temperature control method according to claim 1, characterized in that: in the step 1, the adopted sampling circuit comprises an electric bridge and an amplifying circuit for amplifying the balanced output of the electric bridge; the bridge is composed of a resistor R1, a resistor R2, a resistor R3, a resistor R4 and a temperature sensor on a plug J1, a pair of bridge arms are formed by a reference voltage signal Vf of a reference through the resistor R1, the temperature sensor and the resistor R4 in sequence, and the reference voltage signal Vf of the reference is connected through the resistor R2 and the resistor R3 to form the other pair of bridge arms; the amplifying circuit consists of an operational amplifier U1, a resistor R5, a resistor R6, a resistor R7 and a resistor R8; the common end of the resistor R1 connected with the temperature sensor is connected with the in-phase end of the operational amplifier U1 through a resistor R5, and the common end of the resistor R2 connected with the resistor R3 is connected with the out-phase end of the operational amplifier U1 through a resistor R6; a resistor R7 is provided between the non-inverting terminal of the operational amplifier U1 and ground, and a resistor R8 is provided between the inverting terminal and the output of the operational amplifier U1.

5. The charging pile internal temperature control method according to claim 4, characterized in that: the error calibration of the sampled temperature further comprises the following steps:

step S1, according to the PT1000 degree table, the change relation between the temperature sensed by the sensor and the resistance value is determined to be linear; linear formula: PT is a parameter of the temperature output to the processor, K is a linear coefficient, B is a constant, x is the measured resistance of PT 1000;

step S2, calculating an AD theoretical value Y1 through the operational amplifier circuit, wherein the corresponding resistance value at the first set temperature is R0 omega; the temperature sampling circuit uses an R0 omega precision resistor to replace a PT1000 probe to measure a corresponding AD actual value X1;

step S3, calculating an AD theoretical value Y2 through the operational amplifier circuit, wherein the corresponding resistance value at the second set temperature is R1 omega; the temperature sampling circuit uses an R1 omega precision resistor to replace a PT1000 probe to measure a corresponding AD actual value X2;

step S4, calculating K, B value through a linear equation of two-dimension to obtain the linear deviation relation between the actual measurement value and the theoretical value,

X1*K+B=Y1;

X2*K+B=Y2;

and step S5, storing K, B in the controller, wherein in practical application, the system samples the voltage of the PT1000 to calculate an actual value AD value X measured by current sampling, and calculates a theoretical AD value Y by correcting and calculating K and B according to X × K + B = Y.

And calculating a corresponding resistance value of the theoretical AD value Y through the operational amplifier current, and obtaining a corresponding temperature value in a table look-up mode.

Technical Field

The invention relates to the field of charging piles, in particular to a charging pile internal temperature control method.

Background

With the increasing exhaustion of the world petroleum resources, the power source of the automobile has to gradually get rid of the constraint of the petroleum resources and adopt some new energy, which directly pushes a great technical revolution of the automobile industry, and the trend that the new energy automobile replaces the traditional automobile becomes inevitable in the future.

The automobile charging pile serving as a charging core of the new energy electric automobile can be rapidly developed, and can promote huge industrial economic effects, and huge market space is generally seen in the industry.

The alternating current-direct current fills electric pile and gives the car charging process because power is big, will arouse a great deal of security problem certainly. How to reduce the potential safety hazard of charging is a high concern for manufacturers. A new national standard is released at the end of 2015, the new standard carries out comprehensive systematic specification on a charging interface and a communication protocol, and interconnection and intercommunication between an electric automobile and charging equipment are ensured. This contributes to the general popularity of the entire electric vehicle charging network. Therefore, a reliable measurement and over-temperature safety control mode for the internal temperature of the charging pile needs to be developed.

When charging the car, fill the high-power output electric energy of electric pile, fill the inside a large amount of heats that can produce of electric pile, the battery charging outfit structural design need design for reaching waterproof standard for airtight mode relatively simultaneously. Fill the inside heat that produces of electric pile and be greater than cooling system heat dissipation capacity, fill the inside constant heating up that can of electric pile. If fill inside temperature measurement of electric pile unreliable, do not have effectual cooling control to handle during the excess temperature, battery charging outfit's device will last work high temperature under, this life-span that can seriously influence equipment, the device can appear even naturally, leads to the emergence of conflagration.

Disclosure of Invention

The invention provides a method for controlling the internal temperature of a charging pile, aiming at the problems that the heat generated inside the charging pile with a sealing structure is larger than the heat dissipation capacity of a heat dissipation system, the temperature inside the charging pile can be continuously increased, and the internal temperature of the charging pile needs to be monitored in real time.

The technical scheme adopted by the invention for realizing the technical purpose is as follows: a method for controlling the internal temperature of a charging pile is characterized in that a PT1000 temperature measuring resistor is adopted in the charging pile, and an AD converter is used for accurately acquiring data; the method is characterized in that: the method comprises the following steps:

step 1, performing AD conversion on PT1000 temperature measuring resistor output;

step 2, judging whether the measuring times reach the set times or not; if the set times are reached, turning to the step 3, otherwise, turning to the step 1;

step 3, sequencing the measurement data with set times, taking an intermediate value, and resetting the measurement times;

step 4, judging whether the temperature is normal, if so, turning to the step 1, otherwise, turning to the step 5;

step 5, judging whether the temperature is over-temperature alarm or over-temperature fault, if so, turning to step 6, and if so, turning to step 7;

step 6, reducing power output, and turning to the step 1;

and 7, stopping output and reporting the temperature fault.

According to the invention, the temperature in the charging pile is detected in real time, and an overtemperature alarm or an overtemperature fault is respectively processed when the overtemperature alarm or the overtemperature fault is found.

Further, in the charging pile internal temperature control method: the set number of times in step 2 is 100.

Further, in the charging pile internal temperature control method: in step 6, an over-temperature alarm is also sent out while the power output is reduced.

Further, in the charging pile internal temperature control method: in the step 1, the adopted sampling circuit comprises an electric bridge and an amplifying circuit for amplifying the balanced output of the electric bridge; the bridge is composed of a resistor R1, a resistor R2, a resistor R3, a resistor R4 and a temperature sensor on a plug J1, a pair of bridge arms are formed by a reference voltage signal Vf of a reference through the resistor R1, the temperature sensor and the resistor R4 in sequence, and the reference voltage signal Vf of the reference is connected through the resistor R2 and the resistor R3 to form the other pair of bridge arms; the amplifying circuit consists of an operational amplifier U1, a resistor R5, a resistor R6, a resistor R7 and a resistor R8; the common end of the resistor R1 connected with the temperature sensor is connected with the in-phase end of the operational amplifier U1 through a resistor R5, and the common end of the resistor R2 connected with the resistor R3 is connected with the out-phase end of the operational amplifier U1 through a resistor R6; a resistor R7 is provided between the non-inverting terminal of the operational amplifier U1 and ground, and a resistor R8 is provided between the inverting terminal and the output of the operational amplifier U1.

Further, in the charging pile internal temperature control method: the error calibration of the sampled temperature further comprises the following steps:

step S1, according to the PT1000 degree table, the change relation between the temperature sensed by the sensor and the resistance value is determined to be linear; linear formula:PT is a parameter of the temperature output to the processor, K is a linear coefficient, B is a constant, and x is the measured resistance of PT 1000;

step S2, calculating an AD theoretical value Y1 through the operational amplifier circuit, wherein the corresponding resistance value at the first set temperature is R0 omega; the temperature sampling circuit uses an R0 omega precision resistor to replace a PT1000 probe to measure a corresponding AD actual value X1;

step S3, calculating an AD theoretical value Y2 through the operational amplifier circuit, wherein the corresponding resistance value at the second set temperature is R1 omega; the temperature sampling circuit uses an R1 omega precision resistor to replace a PT1000 probe to measure a corresponding AD actual value X2;

step S4, calculating K, B value through a linear equation of two-dimension to obtain the linear deviation relation between the actual measurement value and the theoretical value,

X1*K+B=Y1;

X2*K+B=Y2;

and step S5, storing K, B in the controller, wherein in practical application, the system samples the voltage of the PT1000 to calculate an actual value AD value X measured by current sampling, and calculates a theoretical AD value Y by correcting and calculating K and B according to X × K + B = Y. And calculating a corresponding resistance value of the theoretical AD value Y through the operational amplifier current, and obtaining a corresponding temperature value in a table look-up mode.

The present invention will be further described with reference to the accompanying drawings and detailed description.

Drawings

Fig. 1 is a flow chart of a method for controlling the internal temperature of an electric pile according to embodiment 1 of the present invention.

Fig. 2 is a sampling circuit used in the method for controlling the internal temperature of an electric pile according to embodiment 1 of the present invention.

Detailed Description