Electronic function test method for high-voltage PTC electric heater

Abstract

The application discloses a high-voltage PTC electric heater electronic function test method, which comprises the following steps: 1, detecting peak current; 2, measuring steady-state current; then calculating standard power; 3, sequentially closing all the sub-regions, and recording the corresponding current when the current is stable after each time of closing the corresponding sub-region; then calculating the steady-state current of each sub-region; 4, detecting no-current data in a normal DC voltage environment; 5, detecting the working current of each sub-region under an ultrahigh DC voltage and comparing with the standard; 6, detecting no-current data 2 in an ultrahigh DC voltage environment, and simultaneously detecting the discharge time S required when the voltage drops to 60V 放电 ; 7, after the test is completed, judging all test items. The application can more stably and accurately measure the standard power and the maximum heating capacity, can guarantee the sub-region current balance of the high-voltage PTC electric heater out of the factory, and through the detection of the ultrahigh DC voltage, can ensure the quality stability of the product.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high-voltage PTC electric heater manufacturing, in particular to a high-voltage PTC electric heater electronic function test method. BACKGROUND

[0002] The high-voltage PTC electric heater in the thermal control system of an electric vehicle is an indispensable component.

[0003] In the prior art, the usual way to test the high-voltage PTC electric heater is to test the outlet temperature at a specific air volume and estimate the standard power of the high-voltage PTC electric heater as a whole, without detecting the steady-state current. Because the steady-state current is the only indicator of the nominal power, the standard power cannot be accurately obtained. At the same time, the high-voltage PTC electric heater partition current is not tested, and the heating capacity of each partition cannot be guaranteed to be completely balanced. And there is no performance detection under super-high direct current voltage.

[0004] In actual application, the existing detection technology cannot determine the balance of the partition current, so it cannot guarantee the balance of the outlet temperature of each outlet in the vehicle, and thus cannot guarantee the comfort experience.

[0005] Therefore, how to detect the partition current of the high-voltage PTC electric heater and the temperature relationship corresponding to each outlet in the vehicle have become technical problems that need to be solved by those skilled in the art. SUMMARY

[0006] In view of the problems that the prior art cannot accurately measure the standard power of the high-voltage PTC electric heater and cannot ensure the balance of the outlet air temperature of each outlet in the vehicle by measuring the partition current, the present application provides a high-voltage PTC electric heater electronic function test method.

[0007] To achieve the above-mentioned purpose, the present application discloses a high-voltage PTC electric heater electronic function test method, the high-voltage PTC electric heater comprising a core body and a circuit board controller; the core body comprises N partitions controlled to open and close by the circuit board controller; comprising the following steps:

[0008] Step 1, apply a normal direct current voltage to the test piece, and turn on all the partitions, and record the peak current I_peak when the current reaches the highest value and stabilizes;

[0009] Step 2, measure the steady-state current I_stable(N); the fan takes away the heat generated by the core body after the current reaches the highest value and stabilizes, and records the measured steady-state current I_stable(N) after the current stabilizes;

[0010] Then calculate the value of I_stable(N)*normal direct current voltage to obtain the standard power;

[0011] Step 3, turn off all the partitions in turn, and after each corresponding partition is turned off, record the corresponding current I_stable(N-1) to I_stable(1) when the current is stable; then calculate the steady-state current I_stable(partition 1) to I_stable(partition N) of each partition;

[0012] Step 4, detect the no-current data I_no current1 in the normal DC voltage environment, turn off all the partitions, and remove the fan, and observe whether I_no current1 is within the range of 0 to 2.4 amperes;

[0013] Step 5, detect the working current I_ON(partition 1) to I_ON(partition N) of each partition under the super-high DC voltage, and compare it with the standard to determine whether the to-be-tested piece still performs qualified under the super-high DC voltage;

[0014] Step 6, detect the no-current data I_no current2 in the super-high DC voltage environment, and simultaneously detect the discharge time S required for the voltage to drop to 60V 放电 ;

[0015] Step 7, after the test is completed, judge all test items, and if any one or more items is unqualified, the overall test result is unqualified;

[0016] For the to-be-tested piece with the qualified overall test result, write the measured data and to-be-tested piece information in the circuit board controller through LIN communication control.

[0017] The application can detect the current of each partition of the high-voltage PTC electric heater, more stably and accurately measure the standard power, and ensure the balance of the partition current of the high-voltage PTC electric heater out of the factory, and through the detection of the super-high DC voltage, ensure the stable quality of the product.

[0018] Preferably, in step 3, if the first partition is not turned off or there is no first partition, the test result I_stable(partition 1) of the first partition is recorded as 0.

[0019] Preferably, in steps 1 to 3, if the circuit board controller appears a fault code, end the test process, and determine that the corresponding to-be-tested piece is an unqualified product.

[0020] Preferably, in step 5, the working current I_ON(partition 1) to I_ON(partition N) of each partition can be directly read by the circuit board controller.

[0021] Preferably, in step 7, the to-be-tested piece information includes a product serial number, a production date and a detection date.

[0022] Preferably, in step 2, the temperature average value of the tested piece reaching the steady current I_stable(N) instant is detected by setting multiple thermocouples at the air inlet of the tested piece.

[0023] Preferably, the tested piece is provided with voltage variable power supply by programmable power supply.

[0024] Preferably, the fan is speed-adjusted by frequency conversion and is set on the sliding guide.

[0025] Preferably, after step 7, the data in the circuit board controller and the tested piece information are detected, and if qualified, a qualified certificate is printed and pasted.

[0026] Preferably, in step 3, the calculation formula of the steady current I_stable(part 1) to I_stable(part N) of each partition is as follows:

[0027] I_stable(part N) = I_stable(N) - I_stable(N-1);

[0028] …

[0029] I_stable(part 2) = I_stable(2) - I_stable(1);

[0030] I_stable(part 1) = I_stable(1).

[0031] The concept, specific structure and generated technical effects of the present application will be further described below in combination with the drawings, so as to fully understand the purpose, features and effects of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 The test flow chart of an embodiment of the present application is shown.

[0033] Figure 2 The schematic diagram of the fan and thermocouple setting position in an embodiment of the present application is shown.

[0034] Figure 3 The voltage and current curve diagram obtained according to the test time in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0035] EMBODIMENT

[0036] As Figure 1 and Figure 3As shown, the high-voltage PTC electric heater electronic function test method, the high-voltage PTC electric heater includes a core and a circuit board controller; The core includes N sub-zones controlled by the circuit board controller; It includes the following steps:

[0037] Step 1, apply normal DC voltage to the test piece, and open all sub-zones, and record the peak current I_peak when the current reaches the maximum value and stabilizes;

[0038] Step 2, measure the steady-state current I_stable(N); The fan is used to remove the heat generated by the core when the current reaches the maximum value and stabilizes, and the measured steady-state current I_stable(N) is recorded after the current stabilizes;

[0039] Then calculate the value of I_stable(N)*normal DC voltage to obtain the standard power;

[0040] Step 3, close all the sub-zones in turn, and record the corresponding current I_stable(N-1) to I_stable(1) when the current stabilizes after closing each sub-zone; Then calculate to obtain the steady-state current I_stable(sub-zone 1) to I_stable(sub-zone N) of each sub-zone;

[0041] During the entire process of steps 1 to 3, check whether there is a fault code in the circuit board controller, if there is a fault code, the test is directly ended, and the product is determined to be unqualified.

[0042] Step 4, detect the no-current data I_no current1 in the normal DC voltage environment, close all sub-zones, and remove the fan, and observe whether I_no current1 is within the range of 0 to 2.4 amperes;

[0043] Step 5, detect the working current I_ON(sub-zone 1) to I_ON(sub-zone N) of each sub-zone under the super-high DC voltage, and compare with the standard to determine whether the test piece is still qualified under the super-high DC voltage;

[0044] Step 6, detect the no-current data I_no current2 in the super-high DC voltage environment, and detect the discharge time S required when the voltage drops to 60V 放电 ;

[0045] Step 7, after completing the test, judge all test items, if any one or more is unqualified, the total test result is unqualified;

[0046] For the test piece with a qualified total test result, write the measured data, test piece information in the circuit board controller through LIN communication control.

[0047] The application can detect the current of each partition of the high-voltage PTC electric heater by measuring the steady current I_stable(N), sequentially closing all partitions one by one, recording the corresponding current I_stable(N-1) to I_stable(1) when the current is stable after closing each partition, and then calculating the steady current I_stable(partition 1) to I_stable(partition N-1) of each partition.

[0048] In practical applications, the normal direct current voltage usually ranges from 310V to 390V, and specifically can be 330V, 350V or 370V; the super-high direct current voltage usually ranges from 410V to 490V, and specifically can be 430V, 450V or 470V.

[0049] Moreover, the steady current I_stable(N) is the only index for measuring whether the standard power of the high-voltage PTC electric heater meets the standard, which is directly related to the material properties of the heating ceramic and the environmental temperature value T, and in practical applications, the environmental temperature value T is involved in the calculation to obtain the steady current.

[0050] Generally, the environmental temperature value T is the average temperature value of the temperature detected by multiple thermocouples when the to-be-tested member reaches the steady current instant.

[0051] In practical applications, the high-voltage PTC electric heater comprises a circuit board IGBT arranged between the core body and the circuit board controller.

[0052] In some embodiments, in step 3, if the first partition is not closed or there is no first partition, the test result I_stable(partition 1) of the first partition is recorded as 0.

[0053] In practical applications, the above technical means can make the test method applicable to high-voltage PTC electric heaters comprising multiple partitions with different numbers.

[0054] In some embodiments, in steps 1 to 3, if a fault code appears on the circuit board controller, the test process is ended, and the corresponding to-be-tested member is determined as an unqualified product.

[0055] In practical applications, the appearance of a fault code represents that the circuit board itself has a fault, so if such a situation occurs, the subsequent test is meaningless, and the test process can be immediately ended.

[0056] In some embodiments, in step 5, the working current I_ON(partition 1) to I_ON(partition N) of each partition can be directly read by the circuit board controller.

[0057] In practical application, the performance of high-voltage PTC electric heater can be directly and quickly judged by directly reading I_ON(part 1) to I_ON(part N) through the circuit board controller.

[0058] In some embodiments, in step 7, the test piece information includes product serial number, production date and detection date.

[0059] In some embodiments, in step 2, the average temperature value of the transient state, i.e. the above-mentioned ambient temperature value T, is detected by setting multiple thermocouples at the air inlet of the test piece to detect the temperature of the test piece reaching the steady-state current I_stable(N).

[0060] In practical application, the transient average temperature value is conducive to calculating the accurate standard power.

[0061] In some embodiments, the test piece is provided with variable voltage by a programmable power supply.

[0062] In practical application, the programmable power supply needs to apply two different voltage environments, i.e. normal DC voltage and super-high DC voltage.

[0063] As shown in Figure 2 In some embodiments, the fan is variable frequency speed-regulated and arranged on the sliding guide rail.

[0064] In practical application, the sliding guide rail can provide different positions for the fan at different test stages and facilitate movement between different positions.

[0065] In some embodiments, after step 7, the data in the circuit board controller and the test piece information are detected, and if qualified, a qualified certificate is printed and pasted.

[0066] In practical application, the data and information written into the circuit board controller are compared and confirmed, and only after the confirmation, the qualified certificate can be printed and pasted.

[0067] In some embodiments, in step 3, the calculation formula of the steady-state current I_stable(part 1) to I_stable(part N) of each part is as follows:

[0068] I_stable(part N) = I_stable(N) - I_stable(N-1);

[0069] …

[0070] I_stable(part 2) = I_stable(2) - I_stable(1);

[0071] I_stable(part 1) = I_stable(1).

[0072] In practical applications, the above calculation method is advantageous to exclude the influence of the environment so as to measure the accurate partition steady-state current.

[0073] The preferred embodiments of the present application are described in detail above. It should be understood that those of ordinary skill in the art can make modifications and variations without departing from the concept of the present application. Therefore, the technical solutions obtained by logical analysis, reasoning or limited experiments based on the prior art according to the concept of the present application should be within the protection scope defined by the claims.

Claims

1. A method for testing the electronic functions of a high-voltage PTC electric heater, wherein the high-voltage PTC electric heater comprises a core and a circuit board controller; the core comprises N zones whose opening and closing are controlled by the circuit board controller; characterized in that, Includes the following steps: Step 1: Apply a normal DC voltage to the test piece and open all the partitions. After the current reaches its maximum value and stabilizes, record it as the peak current I_peak. If the circuit board controller displays a fault code, the test process ends and the corresponding test piece is determined to be a defective product. Step 2: Measure the steady-state current I_stable (N); Use a fan to remove the heat generated by the core after the current reaches its maximum value and stabilizes. Record the measured steady-state current I_stable (N) after the current stabilizes. Then calculate the value of I_stable(N) * normal DC voltage to obtain the standard power; By setting multiple thermocouples at the air inlet of the test piece, the average temperature of the test piece reaches the steady-state current I_stable(N) instantaneous value. If the circuit board controller displays a fault code, the test process ends and the corresponding test piece is determined to be a defective product. Step 3: Sequentially shut down all the partitions, and after each partition is shut down, record the corresponding current I_stable(N-1) to I_stable(1) when the current is stable; then calculate the steady-state current I_stable(partition 1) to I_stable(partition N) for each partition. If the partition described in the first description is not closed or there is no partition described in the first description, then the test result I_stable (partition 1) of the partition described in the first description is recorded as 0; If the circuit board controller displays a fault code, the test process ends and the corresponding test piece is determined to be a defective product. Step 4: Detect the no-current data I_no current1 under normal DC voltage environment, shut down all the partitions, remove the fan, and observe whether I_no current1 is within the range of 0 to 2.4 Amperes; Step 5: Detect the operating current I_ON (section 1) to I_ON (section N) of each section under ultra-high DC voltage and compare it with the standard to determine whether the test piece still performs qualified under ultra-high DC voltage. The operating current I_ON (partition 1) to I_ON (partition N) of each partition can be directly read by the circuit board controller; Step 6: Detect the no-current data I_no current2 in the ultra-high DC voltage environment, and simultaneously detect the discharge time required for the voltage to drop to 60V. ; Step 7: After completing the test, judge all test items. If any one or more items fail, the overall test result is unqualified. For the test piece that passes the overall test, the measured data and test piece information are written into the circuit board controller via LIN communication.

2. The method for testing the electronic function of a high-voltage PTC electric heater according to claim 1, characterized in that, In step 7, the test piece information includes the product serial number, production date, and testing date.

3. The method for testing the electronic function of a high-voltage PTC electric heater according to claim 1, characterized in that, The device under test is powered by a programmable power supply with variable voltage.

4. The method for testing the electronic function of a high-voltage PTC electric heater according to claim 1, characterized in that, The fan is speed-regulated by frequency converter and is mounted on a sliding guide rail.

5. The method for testing the electronic function of a high-voltage PTC electric heater according to claim 1, characterized in that, After completing step 7, the data and test piece information in the circuit board controller are checked. If they pass, a certificate of conformity is printed and affixed.

6. The method for testing the electronic function of a high-voltage PTC electric heater according to claim 1, characterized in that, In step 3, the formulas for calculating the steady-state current I_stable (partition 1) to I_stable (partition N) for each partition are as follows: I_stable(Partition N) = I_stable(N) - I_stable(N - 1); …… I_stable(Partition 2) = I_stable(2) - I_stable(1); I_stable(Partition 1) = I_stable(1).

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