CN100566009C - Electronic load simulation charger method of operation and device thereof - Google Patents

Abstract

The invention provides a kind of electronic load simulation charger method of operation and device thereof.This method comprises the steps: at first, and a charger to be measured is connected an electronic load to constitute a charge circuit; Subsequently, set at least one predeterminated voltage value and the predetermined current restriction of this electronic load; Next, according to this predeterminated voltage value and predetermined current restriction, calculate corresponding one default resistance value; Then, start this electronic load, and begin to produce charging current and carry out emulation according to aforementioned default resistance value; Reach when stablizing in electronic load and charger to be measured, measure the charging voltage value of charger to be measured and charging current value at least one of them; If charging voltage value differs from the predeterminated voltage value or charging current value differs from the predetermined current restriction, then default resistance value is compensated, with charging voltage value and the charging current value that changes charger to be measured; The charging voltage value that this compensation process proceeds to after the compensation always is equal to the predeterminated voltage value.

Description

Electronic load emulation charger operating method and device thereof

technical field

The invention relates to a method for simulating a charger to charge a battery and a device thereof, in particular to an operation method and a device for simulating a charger to charge a battery with an electronic load.

Background technique

Nowadays, electronic load (electronic load) test chargers are used to charge batteries, all of which operate in constant voltage mode (CV Mode, Constant Voltage Mode). That is, by changing the charging current, the charger under test can achieve a constant current output, and at the same time make the charger under test work according to the voltage set by the electronic load.

Please refer to FIG. 1 , which is a schematic block diagram of a typical device for simulating the behavior of a charger charging a battery by using an electronic load. In the dotted line in the figure is a charger 10 to be tested, and the electronic load unit 20 is connected to the charger 10 to be tested to form a charging circuit. The micro control unit (MPU) 30 is connected to the voltage measuring terminal of the electronic load unit 20 through a circuit, so as to measure the voltage value Vo thereof.

FIG. 2 is a flow chart of simulating the battery charging behavior of the charger using the device in FIG. 1 . As shown in the figure, after setting the preset voltage value of the electronic load (see step 120), start the electronic load (see step 130). Subsequently, measure the voltage value Vo of the voltage measuring terminal (see step 140). Next, as shown in step 150 , it is compared whether the voltage value Vo is the same as the voltage value set by the electronic load. If not, as shown in step 160, when the measured voltage value Vo is higher than the voltage set by the electronic load, the micro control unit 30 controls the electronic load unit 20 to increase the voltage on the loop through a digital-to-analog converter (DAC). Current Io, so that the voltage value Vo drops. On the contrary, the micro control unit 30 controls the electronic load unit 20 to reduce the current Io through the digital-to-analog converter to increase the voltage Vo. After repeated adjustments, the measured voltage Vo can be equal to the set voltage to reach a balance (see step 170).

Basically, before testing the charger with an electronic load, the voltage value in constant voltage mode, the current limit of the load and its response speed will be set. The current limit of the load is to protect the charger under test, so that when the electronic load does not operate in the constant voltage mode according to the characteristics of the charger under test (in the constant voltage mode, it may generate an excessive charging current and endanger the charge under test. device), the charger under test can still obtain basic protection. And the response speed sets the time required for the charger under test to reach the set voltage value from the start.

The constant voltage mode currently used in electronic load simulation in the industry (that is, the test process shown in Figure 1 and Figure 2) adjusts the charging voltage value of the charger under test so that it conforms to the preset voltage value of the electronic load. However, it has not considered whether the charging current generated under this charging voltage matches the actual charging current of the charger under test.

Secondly, the charging behavior of the battery is the result of the interaction between the characteristics of the charger and the battery. In the aforementioned simulation method, the unilateral operation of the electronic load is used to determine, drive or force the action of the charger under test. Even if the stabilized charging voltage value and charging current value conform to the actual charging state, it is still impossible to correctly simulate the process from the beginning of charging until reaching the steady state. Therefore, the present invention proposes a device and method for simulating the operation of a charger with an electronic load, so as to obtain a charging simulation process closer to reality.

Contents of the invention

The main purpose of the present invention is to use the form of impedance to simulate the operation of the charger, so as to obtain a simulation process closer to reality.

The invention provides a device for simulating the operation of a charger with an electronic load, and the device includes an electronic load unit and a micro control unit. The electronic load unit is connected to a charger to be tested and forms a loop with it. The micro control unit has at least a preset voltage value and a preset current limit input, and calculates a corresponding preset impedance value based on the preset voltage value and the preset current limit to control the electronic load unit to generate a charging current . There is a compensation unit in the micro control unit. When the electronic load unit and the charger under test are stable, the compensation unit measures at least one of the charging voltage value and the charging current value of the charger under test, and compares it with the preset voltage. value is compared with the preset current limit. If the charging current value is different from the preset current limit or the charging voltage value is different from the preset voltage value, the preset impedance value is compensated. The compensation step is carried out until the compensated charging voltage is equal to the preset voltage.

According to the aforementioned device, the present invention also provides a method for simulating the operation of a charger with an electronic load. Firstly, a charger to be tested is connected to an electronic load to form a charging circuit. Then, at least a preset voltage value and a preset current limit of the electronic load are set. Next, a corresponding preset impedance value is calculated according to the preset voltage value and the preset current limit. Then, start the electronic load, and start to generate charging current according to the aforementioned preset impedance value for simulation. After a compensation time, when the electronic load and the charger under test are stable, at least one of the charging voltage value and the charging current value of the charger under test is measured. If the charging voltage value is different from the preset voltage value or the charging current value is different from the preset current limit, the preset impedance value is compensated to change the charging voltage value and the charging current value of the charger to be tested. The compensation step is carried out until the compensated charging voltage is equal to the preset voltage.

To sum up, compared with the traditional method of simulating the operation of the charger in the constant voltage mode, the present invention uses the form of impedance to simulate the operation of the charger, which can avoid the unilateral operation of the electronic load in the traditional way to determine, drive or force The shortcomings produced by the action of the charger under test, so that the simulation results are closer to reality. At the same time, through proper parameter setting, the present invention can more accurately simulate the process from the start of charging until reaching a steady state.

Description of drawings

FIG. 1 is a schematic block diagram of a typical device for simulating the behavior of a charger charging a battery with an electronic load;

2 is a flowchart of a method for simulating charger operation using the apparatus of FIG. 1;

3 is a schematic block diagram of a preferred embodiment of the device for simulating the battery charging behavior of the charger with an electronic load according to the present invention;

FIG. 4 is a flow chart of a preferred embodiment of a method for simulating the operation of a charger using the device shown in FIG. 3 of the present invention;

FIG. 5 is a graph illustrating the process of changing the charging current value and the charging voltage value under the operation of the compensation program of the present invention;

FIG. 6 is a graph simulated by a preferred embodiment of the method for simulating the operation of a charger using an electronic load according to the present invention.

Description of main component symbols:

Charger to be tested 10 Electronic load unit 40

Micro control unit 50 Compensation unit 52

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings.

Please refer to FIG. 3 , which is a schematic block diagram of a preferred embodiment of a device for simulating a charger charging a battery by using an electronic load according to the present invention. As shown in the figure, the device is mainly composed of an electronic load unit 40 and a micro control unit 50 . The microcontroller unit 50 also has a compensation unit 52 therein.

Wherein, the electronic load unit 40 is connected to a charger 10 under test, and forms a charging circuit with it. The micro control unit 50 is input with at least a preset voltage value Vp and a preset current limit Ip, and calculates a corresponding preset impedance value Rp according to the preset voltage value Vp and the preset current limit Ip. Then, the microcontroller unit 50 controls the electronic load unit 40 to generate a charging current through a digital-to-analog converter (DAC) according to the preset impedance value Rp. The compensation unit 52 measures at least one of the charging voltage value Vo and the charging current value Io of the charger 10 under test through an analog-to-digital converter (ADC) when the electronic load unit 40 and the charger 10 under test are stable, and Compared with the preset voltage value Vp and the preset current limit Ip. If the charging current value Io is different from the preset current limit Ip or the charging voltage Vo is different from the preset voltage value Vp, the preset impedance value Rp is compensated. This compensation step is carried out until the compensated charging voltage Vo' is equal to the preset voltage Vp.

At the same time, please refer to FIG. 4 , a flow chart of a preferred embodiment of the method for simulating the operation of a charger using the device in FIG. 3 of the present invention. First, as shown in step 210, the charger to be tested is connected to the electronic load to start the simulation program. Then, as shown in step 220 , at least a preset voltage value Vp and a preset current limit Ip of the electronic load are set. Next, as shown in step 230 , a corresponding preset impedance value Rp is calculated according to the preset voltage value Vp and the preset current limit Ip. Basically, the preset impedance value Rp is equal to the preset voltage value Vp divided by the preset current limit Ip (Rp=Vp/Ip).

Then, as shown in step 240, the electronic load is turned on, and starts to generate a charging current according to the aforementioned preset impedance value Rp for simulation. In this case, the electronic load is simulated in constant impedance mode. For the charger under test, it is as if it is connected to an impedance (Impedance) with this preset impedance value.

Next, as shown in step 250, after a certain period of time to stabilize the electronic load and the charger under test (usually when the charger under test is in constant current and constant voltage output), measure the current charging voltage value of the charger under test At least one of Vo and the charging current value Io.

Then, as shown in step 260 , the measured charging voltage Vo is compared with the preset voltage value Vp, and the charging current value Io is compared with the preset current limit Ip. If the charging voltage value is different from the preset voltage value (Vo≠Vp) or the charging current value is different from the preset current limit (Io≠Ip), then perform the compensation procedure following step 270 on the preset impedance value Rp to change the Measure the charging voltage Vo and charging current Io of the charger. If they are the same, as shown in step 280, it means that the preset impedance value Rp is a correct simulation parameter, and no compensation procedure is needed. Basically, the compensation process continues until the compensated charging voltage Vo is equal to the preset voltage Vp.

FIG. 4 also shows a preferred embodiment of the compensation procedure of the present invention. First, as shown in step 270, according to the preset voltage value Vp input in step 220 and the charging current value Io measured before compensation, the impedance value Ro' after compensation is set to change the setting of the electronic load. Basically, the compensated impedance value Ro' is equal to the preset voltage value Vp divided by the charging current value Io (Ro'=Vp/Io).

Then, repeating steps 250 and 260, when the electronic load and the charger under test are stable, at least one of the compensated charging voltage Vo' and the compensated charging current Io' of the charger under test is measured. Next, compare the measured charging voltage value (that is, the compensated charging voltage value Vo') with the preset voltage value Vp, and the measured charging current value (that is, the compensated charging current value Io') and the compensated The previous charging current value Io (different from the preset current limit Ip in the original simulation process). If the compensated charging voltage value Vo' is different from the preset voltage value Vp, repeat the aforementioned compensation procedure. If they are the same, the compensated impedance value Ro' is the correct simulation parameter.

Please refer to FIG. 5 , which illustrates the process of changing the charging current value Io and the charging voltage value Vo under the operation of the aforementioned compensation procedure. Assume that the actual charging voltage of the charger under test is 14V, and the actual current limit is 3A. However, the preset current limit set by the electronic load is 2A, and the preset voltage value is 12V. The preset impedance value estimated according to the preset current limit and the preset voltage value is 6 ohms. Therefore, the electronic load simulates an impedance of 6 ohms.

Operating this electronic load will inevitably fail to make the charger under test reach a steady-state voltage of 12V. Operate with this 6 ohm impedance, and cooperate with the actual charging voltage (14V) of the charger to be tested, the measured charging current value is 2.33A (that is, the actual charging voltage (14V) of the charger to be tested divided by 6 ohm impedance). The charging current value of 2.33A is the basis for setting the impedance value in the subsequent compensation procedure. That is, by using the measured charging current value of 2.33A and the preset voltage value of 12V, the compensated impedance value is estimated to be 5.15 ohms (that is, the preset voltage value of 12V is divided by the charging current value of 2.33A). With the impedance of 5.15 ohms matched with the actual charging voltage (14V) of the charger to be tested, the measured charging current value is 2.71A. The charging current value of 2.71A is used as the basis for setting the impedance value in the subsequent compensation procedure. That is, by using the measured charging current value of 2.71A and the preset voltage value of 12V, the compensated impedance value is estimated to be 4.42 ohms (that is, the preset voltage value of 12V is divided by the charging current value of 2.71A). With this impedance of 4.42 ohms and the actual charging voltage (14V) of the charger under test, a charging current of 3.17A should have been generated. However, limited by the actual current limit of the charger under test to 3A, the measured The charging current value is 3A. The charging current value of 3A is then used as the basis for setting the impedance value in the subsequent compensation procedure. Under the condition that the preset current limit is 3A and the preset voltage value is 12V, the estimated impedance value after compensation is 4 ohms. Operating with this impedance of 4 ohms, the measured charging voltage value (the impedance of 4 ohms multiplied by the charging current of 3A) will be consistent with the preset voltage value of 12V.

It should be noted that, through the aforementioned compensation procedure, the actual current limit of the charger under test can be known. In order to correctly simulate the actual operation, the preset current value Ip of the electronic load should be set to the correct current limit in step 120 , so as to simulate the actual operation of the charger under test with the correct setting.

Please refer to FIG. 6 , which is a graph simulated by a preferred embodiment of the method for simulating the operation of a charger using an electronic load according to the present invention. In order to correctly simulate the operation of the charger, in this embodiment, a preset voltage value Vp, a preset current limit Ip, a response time Tr and a start-up voltage value Vs are set for the electronic load. Wherein, the preset voltage value Vp and the preset current limit Ip are used to calculate the preset impedance value Rp to be simulated by the electronic load. The starting voltage value Vs must be smaller than the preset voltage value Vp.

In the figure, t ₀ is the moment when the electronic load starts. After the electronic load is started, by setting the starting voltage value Vp, the micro control unit can control the electronic load to generate the charging current I when the charging voltage V of the charger to be tested exceeds the starting voltage value Vs. In addition, by setting the response time Tr, the micro control unit can control the electronic load to reach the preset impedance value Rp within the response time Tr after the charging current starts to be generated.

In addition to the aforementioned four parameters related to the simulation of the charging curve, the setting of the compensation time Tc can also be seen in the figure. The compensation time Tc is the time elapsed from the start of generating the charging current until the measurement of the charging voltage Vo and the charging current Io of the charger to be tested. Therefore, the setting of the compensation time Tc must be sufficient to make the electronic load and the charger reach a stable state.

Compared with the traditional method of simulating the operation of the charger in the constant voltage mode, the present invention uses the impedance (impedance) form to simulate the operation of the charger, which can avoid the unilateral operation of the electronic load in the traditional way to determine, drive or force the action of the charger under test The resulting shortcomings in order to make the simulation results closer to reality. At the same time, through proper parameter setting, the present invention can more accurately simulate the process from the start of charging until reaching a steady state.

The above description utilizes the preferred embodiments to describe the present invention in detail, rather than limiting the scope of the present invention, and those who are familiar with this type of art can understand that it is appropriate to make slight changes and adjustments without losing the gist of the present invention. without departing from the spirit and scope of the invention.

Claims (11)

1. A method for simulating charger operation with an electronic load, characterized in that the method comprises the steps of: Connecting a charger under test to an electronic load to form a charging circuit; setting at least a preset voltage value and a preset current limit of the electronic load; calculating a corresponding preset impedance value according to the preset voltage value and the preset current limit; Starting the electronic load, and starting to generate a charging current according to the preset impedance value; measuring at least one of a charging voltage value and a charging current value of the charger under test when the electronic load and the charger under test are stable; and If the charging voltage value is different from the preset voltage value or the charging current value is different from the preset current limit, the preset impedance value is compensated to change the charging voltage of the charger under test. The charging voltage value and the charging current value until the compensated charging voltage value is equal to the preset voltage value. 2. The method according to claim 1, wherein the step of compensating the preset impedance value comprises: Setting the impedance value after compensation according to the preset voltage value and the charging current value before compensation, so as to change the setting of the electronic load; When the electronic load unit and the charger under test are stable, measuring at least one of a compensated charging voltage value and a compensated charging current value of the charger under test; and If the compensated charging voltage value is different from the preset voltage value, then setting the compensated impedance value equal to the preset voltage value divided by the compensated charging current value, repeating the compensation step, If they are the same, the compensated impedance value is the correct impedance value. 3. The method according to claim 1, further comprising setting a starting voltage value of the electronic load before starting the electronic load, the starting voltage value being smaller than the preset voltage value, After the electronic load is started and the charging voltage of the charger under test exceeds the starting voltage value, the charging current starts to be generated. 4. The method according to claim 1, further comprising setting a response time of the electronic load before starting the electronic load, so that the electronic load starts to generate charging current after the The preset impedance value is reached within the response time. 5. The method according to claim 1, further comprising setting a compensation time of the electronic load before starting the electronic load, the compensation time being generated from the charging current to the measurement The elapsed time of the charging voltage value and charging current value of the charger to be tested. 6 . The method according to claim 1 , wherein when the electronic load and the charger under test are stable, the charger under test is outputting at a constant current and a constant voltage. 7. A method for simulating charger operation with an electronic load, characterized in that the method comprises the steps of: Connecting a charger under test to an electronic load to form a charging circuit; setting a preset voltage value, a preset current limit, a startup voltage value and a response time of the electronic load, the startup voltage value being smaller than the preset voltage value; calculating a corresponding preset impedance value according to the preset voltage value and the preset current limit; Starting the electronic load according to the starting voltage value, the response time and the preset impedance value, the electronic load starts to generate charging current after the voltage of the charger under test exceeds the starting voltage value, And, the electronic load reaches the preset impedance value within the response time after starting to generate the charging current; After starting the electronic load, it also includes measuring the charger under test when the electronic load and the charger under test are stable, that is, when the charger under test is outputting a constant current and a constant voltage. At least one of the charging voltage value and the charging current value; and If the charging voltage value is different from the preset voltage value or the charging current value is different from the preset current limit, the preset impedance value is compensated to change the charging voltage of the charger under test. The charging voltage value and the charging current value until the compensated charging voltage value is equal to the preset voltage value. 8. The method according to claim 7, further comprising setting a compensation time of the electronic load before starting the electronic load, the compensation time is from the generation of the charging current to the measurement The elapsed time of the charging voltage value and charging current value of the charger to be tested. 9. The method according to claim 7, wherein the step of compensating the preset impedance value comprises: Setting the impedance value after compensation according to the preset voltage value and the charging current value before compensation, so as to change the setting of the electronic load; When the electronic load unit and the charger under test are stable, measuring at least one of a compensated charging voltage value and a compensated charging current value of the charger under test; and If the compensated charging voltage value is different from the preset voltage value, then setting the compensated impedance value equal to the preset voltage value divided by the compensated charging current value, repeating the compensation step, If they are the same, the compensated impedance value is the correct impedance value. 10. The method according to claim 7, wherein if the correct current limit of the charger under test is known, then setting the preset current limit of the electronic load to the correct current limit. 11. A device for simulating charger operation with an electronic load, characterized in that the device comprises: An electronic load unit is connected to a charger under test and forms a charging circuit with it; and A micro control unit, input with at least one preset voltage value and a preset current limit, and calculate a corresponding preset impedance value according to the preset voltage value and the preset current limit to control the The electronic load unit generates charging current, and the micro control unit includes: A compensation unit, when the electronic load unit and the charger under test are stable, measure at least one of the charging voltage value and the charging current value of the charger under test, and compare it with the preset voltage value Compared with the preset current limit, if the charging current value is different from the preset current limit or the charging voltage value is different from the preset voltage value, then compensate the preset impedance value , until the compensated charging voltage value is equal to the preset voltage value.

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