JP3582318B2 - Output voltage control method of DC power supply for simulating and outputting drooping characteristics of battery and output voltage control device using the method - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a power supply device for an electric device using a battery as a power source, and in particular, to a DC power supply having characteristics equivalent to a battery, which is optimal for a power supply such as a performance evaluation test of the electric device performed without using a battery. The present invention relates to an output voltage control method for a power supply device (hereinafter referred to as a battery simulator) and an output voltage control device using the method.
[0002]
[Prior art]
Devices using a battery as a power source include, for example, an electric vehicle, a motor for a driving mechanism thereof, and an inverter for driving the same.
Improves the reproducibility of test results as a power source for conducting test runs and evaluation tests at factories and maintenance factories, other than when such an electric vehicle drive mechanism, electric motor and its driving inverter are installed on the actual machine. In some cases, a battery simulator is used in order to reduce the maintenance work of the test power supply battery.
As a configuration example of the battery simulator, a converter that rectifies a commercial power supply to receive power and outputs a predetermined voltage, a chopper that outputs an arbitrary DC voltage according to a command signal created in accordance with the characteristics of a battery used, and There are such control devices.
[0003]
Since a battery has an internal resistance as is well known, a voltage attenuated by the voltage drop due to the load current and the internal resistance is output (generally, the characteristic that the output terminal voltage fluctuates due to such a load current is a drooping characteristic). ).
Since the battery simulator is used as a power source when conducting tests in place of batteries, it is necessary to have characteristics that closely simulate the drooping characteristics of the battery described above in order to obtain accurate data of the device under test. It is.
Accordingly, the battery simulator has a function of setting an internal resistance value that varies according to the state of charge of the battery and a function of calculating a terminal voltage.
[0004]
FIG. 3 shows a functional configuration example of the battery simulator 100 connected to a load.
In FIG. 3, reference numeral 1 denotes a converter, which is connected so as to rectify and convert an input AC power supply AC to DC and supply the output to a chopper 2.
The chopper 2 converts the input voltage into a voltage corresponding to the above-described drooping characteristic by a function to be described later and outputs the voltage to a power load 300 which is a test device, for example.
Therefore, this output voltage corresponds to the output voltage of the battery to be simulated.
FIG. 3 shows that the power load 300 is converted into a predetermined frequency and voltage by the inverter 20 and supplied to the electric motor 31 by the inverter 20. The load of the electric motor 31 is, for example, the driving mechanism 32 of the electric vehicle is a rotational coupling mechanism such as a clutch. 34 shows an example in which they are connected by a link 34.
In the inverter 20, a switching function 21 formed by a switching element (not shown) is automatically operated by an inverter control function 22 so as to output a frequency and a voltage commanded from a higher-level operation function (not shown). .
[0005]
The main function of the battery simulator 100 is constituted by the converter 1 and the chopper 2 as described above. The chopper 2 is a non-load terminal of the corresponding battery output from the setting recording function 106 which records various data of the battery to be simulated. A subtraction function 104 subtracts, from the command voltage signal S21 indicating the voltage value, a drop voltage signal S32 indicating a value corresponding to the voltage dropped by the load current and the internal resistance of the battery by the subtraction function 104, and outputs the corrected output command signal S22 indicating the terminal voltage of the battery. It is controlled by the input output voltage control function 103.
The output voltage control function 103 has a servo function for comparing and following the output command signal S22 and the output voltage signal S23 indicating the battery simulator output voltage value, and outputs a voltage having no error with respect to the output command signal S22. The chopper 2 is controlled to output.
[0006]
The current supplied from the battery simulator 100 to the power load 300 is detected by the current transformer 105, and a current output signal S30 indicating the current value is input to the battery internal characteristic simulation function 107. The battery internal resistance characteristic signal S31 set and recorded by the setting recording function 106 described above is input to the battery internal characteristic simulation function 107. The battery internal characteristic simulation function 107 calculates the product of the values of the two input signals S30 and S31, and inputs the voltage drop signal S32 indicating the battery internal voltage drop value to the subtraction function 104.
In the subtraction function 104, the output voltage signal S22 is generated by subtracting the drop voltage signal S32 from the command voltage signal S21 as described above, and is input to the output voltage control function 103.
Reference numerals 17 and 23 shown in FIG. 3 denote voltage smoothing capacitors for absorbing current / voltage fluctuations, respectively.
[0007]
With the above-described functional configuration, the battery simulator 100 outputs a DC voltage obtained by subtracting, from the input command voltage signal S21, a voltage drop caused by the internal characteristics of the battery to be simulated due to the load current I supplied to the power load 300, and The above current is supplied to the load 300.
Therefore, for example, when the current value supplied to the electric motor 31 is changed by operating the above-described electric vehicle driving mechanism 32 of the electric power load 300, the output voltage value of the battery simulator 100 is correspondingly changed.
Therefore, even if a battery is not used, a test of the power load 300 equivalent to the connection of the battery can be performed.
The setting and recording function 106 for generating the battery internal resistance characteristic signal S31 described above is used to simulate the drooping characteristics of the battery from the current direction and its value depending on the battery type, the charging rate, the electrolyte temperature, the load state of the electric motor, and the like. It has a function to create and output necessary internal resistance characteristic signals corresponding to operating conditions.
The setting recording function 106 may be provided in a higher-level management control device such as a test device.
[0008]
As a prior art of a method and an apparatus for simulating a battery, for example, there is one disclosed in Japanese Patent Application Laid-Open No. 57-124266.
JP 57-124266 discloses a discloses simulation method, the battery terminal voltage - seeking and electromotive force E ₀ no-load state of the battery and the internal resistance R ₀ than the discharge current curve, DC electromotive force E ₀ It is generated by the power supply device and given to the device under test. The load current I at this time is multiplied by the above R ₀ , and the voltage is subtracted from the electromotive force E ₀ to generate a voltage corresponding to E ₀ −IR ₀ in the DC power supply. The voltage drop ΔV per unit time is obtained from the average value I ₀ of the load current I at this time and the above-described battery discharge curve, and this ΔV is calculated as ΔE ₀ = K ₁ ΔV
ΔR ₀ = K ₂ ΔV / I ₀
To obtain ΔE ₀ and ΔR _0, and a voltage that changes with time as E ₀ −ΔE ₀ − (R ₀ + ΔR ₀ ) I is generated in the DC power supply device and supplied to the device under test. The apparatus has the functions described above formed on the apparatus. Note that ΔE ₀ represents a decrease in the electromotive force of the battery per unit time, ΔR ₀ represents an increase in the internal resistance of the battery per unit time, and K ₁ and K ₂ represent the relationship of K ₁ + K ₂ = 1. Is a constant.
[0009]
[Problems to be solved by the invention]
By the way, according to the function of the battery simulator described above, the output current is detected and the voltage corresponding to the voltage drop due to the internal resistance of the battery is obtained.
Generally, a smoothing capacitor is often connected to the inverter circuit, as indicated by reference numeral 23 in FIG.
Therefore, the output current of the battery (battery simulator) is the sum of the charge / discharge current of the capacitor and the load current including the efficiency of the inverter.
However, since the above two currents cannot be detected separately, for example, when the set voltage value is increased in a no-load state, the following problems occur.
(1) Charging current to the capacitor flows to increase the output voltage.
(2) The charging current is detected, and the internal voltage dropping function is activated by the internal resistance value of the battery corresponding to the charging current, so that the output voltage drops.
(3) Since the output voltage decreases, discharge current flows from the capacitor.
(4) The discharge current is detected, and the internal voltage drop function based on the internal resistance value of the battery corresponding to the discharge current is activated, and the output voltage rises in reverse.
(5) Since the output voltage increases, a charging current flows through the capacitor.
(6) The control state vibrates due to the repetition of the above.
(7) The larger the setting of the battery internal resistance value, the more noticeable the above-mentioned state.
[0010]
The above problem can be mitigated by inserting a delay element (for example, a low-pass filter) into the circuit, but responsiveness is sacrificed.
By separating the capacitor current component and the load current component from the inverter current and calculating the voltage drop due to the internal resistance of the battery only from the load current component, it is possible to avoid the above-described control from becoming oscillatory. It is difficult to separate the capacitor current component in the inverter and detect only the load current component flowing into the inverter from the viewpoint of the structure of the inverter.
When the prior art described in Japanese Patent Application Laid-Open No. 57-124266 is used as a power supply for an inverter, similar problems occur.
The present invention solves the above-mentioned problems (problems) of the prior art, and uses an output voltage control method of a DC power supply device that simulates and outputs a drooping characteristic of a battery without the possibility of control becoming oscillating, and uses the method. It is an object to provide an output voltage control device.
[0011]
[Means for Solving the Problems]
In order to solve the above problem, the output voltage control method of a battery simulator for outputting a drooping characteristic of the battery simulated by, in a DC power supply that outputs a drooping characteristic of the battery simulated to, claim 1 If the load is an inverter with a motor as the load, the effective load power is calculated from the output voltage of the inverter and the inverter output current, and the voltage drop corresponding to the internal resistance of the target battery corresponding to this load power is calculated. A value is calculated, and the calculated value is output by simulating the drooping characteristic of a battery which outputs the reduced pressure .
[0012]
In this case, as described in claim 2, when the load is an inverter using a motor as a load, the load power of the DC power supply device is calculated from the output torque and the rotation speed of the motor,
Calculating a voltage drop equivalent value based on the internal resistance of the target battery corresponding to the load power;
The calculated value may be reduced and output.
[0013]
Further, in the output voltage control device to which the above method is applied, in a DC power supply device that simulates and outputs a drooping characteristic of a battery, the load is an inverter using a motor as a load. In this case, means for measuring the output voltage of the inverter, means for measuring the output current of the inverter, and an arithmetic function for calculating the effective load power of the inverter from each value and phase difference of the measured output voltage and the measured output current A storage function for setting and recording the internal resistance signal of the target battery, an arithmetic function for calculating the voltage drop value of the target battery from the calculated load power value and the recorded internal resistance signal of the battery, and a preset output voltage A calculation function for subtracting the voltage drop value of the battery from the value is provided, and output is performed according to the calculation result .
[0014]
Alternatively, when the load of the DC power supply device is an inverter having a motor as a load, a function of detecting an output torque of the motor, a function of detecting a rotation speed, and a value of the detected output torque. A calculation function for calculating the load power of the inverter from the rotation speed value, a storage function for setting and recording an internal resistance signal of the target battery, and a calculation function of the battery based on the calculated load power value and the stored internal resistance signal of the battery. A calculation function for calculating the voltage drop value and a calculation function for subtracting the voltage drop value of the battery from a preset output voltage value may be provided, and the output may be performed according to the calculation result .
[0015]
Since the output voltage control method and the output voltage control device of the battery simulator according to the present invention can be used for the calculation by stably detecting only the pure load component as described above, the voltage control may be oscillated. There is no.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
First embodiment:
Next, a first embodiment of an output voltage control method and a voltage control function of a battery simulator according to the present invention will be described with reference to FIG. 1 in a case where a load of a battery simulator is an inverter having a motor as a load. This will be described in detail.
In FIG. 1, the same reference numerals are used for the same element functions as the element functions shown in FIG. 3 described in the related art, and the detailed description is omitted.
[0017]
In the present embodiment, the electric motor 31 couples a sensor shaft 33 on which a torque sensor and a rotational speed sensor are mounted behind a rotational coupling mechanism 34 serving as a first rotational coupling mechanism. The drive mechanism 32 which is a rotational load is connected via a rotation connection mechanism 35. That is, in the present embodiment, the transmission torque and the rotation speed of the input rotary shaft of the drive mechanism 32 of the electric vehicle described in the related art are measured, and the inverter load is indicated by reference numeral 30. I have.
[0018]
In FIG. 1, the output voltage of a battery simulator 10 according to the present invention is determined by a chopper 2 controlled by an output voltage control function 3.
The output voltage control function 3 has a function of comparing and following the output command signal S2 to be input and the output voltage signal S3 indicating the battery simulator output voltage value, and outputs a voltage having no error with respect to the output command signal S2. The battery simulator 10 is controlled to output.
[0019]
Various data of the battery to be simulated and the characteristics of the load 30 are recorded in the setting recording function 7 in advance, and a command voltage signal S1 output from the setting recording function 7 and indicating a no-load terminal voltage value of the corresponding battery, and a load The subtraction function 4 obtains the above-described output command signal S2 indicating a deviation voltage value between a current and a voltage drop signal S4 indicating a voltage value dropped by the internal resistance of the battery.
[0020]
The torque signal S5 indicating the torque measurement value indicating the absorption power of the load 30 and the rotation speed signal S6 indicating the rotation speed are input to the battery internal characteristic simulation function 6. Further, a characteristic indicating the relationship between the absorbed power and the output power, such as the internal characteristics of the battery set and recorded in the setting recording function 7 and the efficiency of the load 30 obtained by integrating the efficiency of the load 30 and the inverter, is used as the battery correction signal S7. It is input to the battery internal characteristic simulation function 6.
The battery internal characteristics set and recorded in the setting recording function 7 correspond to the required characteristics of the battery simulator 10 and the like, and indicate the state of deterioration of the battery, the state of charge of the battery, the temperature of the electrolyte, and / or the electrolyte. The factors that affect the internal resistance of the battery, such as the specific gravity of the battery simulator, and the characteristics thereof are recorded, so that necessary conditions can be set when the battery simulator 10 is used.
An output voltage signal S3 indicating the battery simulator output voltage value is input to the battery internal characteristic simulation function 6.
[0021]
That is, the measured output torque of the motor, which is the load of the inverter, is T, the rotational speed is N, the absorbed power of the load 30 is P, the output of the battery simulator 10 is P, the load efficiency is ρ, and the settings of the battery simulator 10 are set. Assuming that the voltage is V ₀ , the voltage drop caused by the internal resistance of the battery is V _d , the output voltage of the battery simulator 10 is V, and the output current of the battery simulator 10 is I, the following equation is established.
P = TN / ρ (1)
P = VI (2)
V = V ₀ −V _d (3)
From the above equations (1) and (2), I = TN / Vρ (4)
Therefore, in the battery internal characteristic simulating function 6, first, the output current value I of the battery simulator 10 is calculated based on the above equation (4), and then, as described in the related art, this calculated current value set recorded battery internal characteristics set recording function 7 by calculating the decreased voltage value V _d based on the internal resistance of the battery.
[0022]
Therefore, a battery voltage drop signal S4 indicating the drop voltage value V _d, as shown in the command voltage signal S1 Metropolitan from subtraction function 4 showing a no-load terminal voltage V ₀ to be the set voltage value of the battery (3) to Calculation is performed to obtain an output command signal S2, which is input to the output voltage control function 3.
Therefore, the battery simulator 10 outputs to the load a voltage reduced by a voltage drop based on the internal resistance when the corresponding battery outputs the current I.
[0023]
In the above calculation, the output voltage of the battery simulator used in the calculation before the voltage drop value based on the accurate internal resistance is calculated has a slight deviation from the calculated output voltage. Is quickly corrected in accordance with the response characteristics and the like.
In response to this modification characteristics, instead of the output voltage value V to be used for initial calculations, it may be used to set the voltage value V _0.
Further, in order to speed up the convergence, the approximate calculated force voltage value may be obtained from the characteristics recorded in advance of the corresponding battery and used for the calculation.
[0024]
Second embodiment:
Next, a second embodiment will be described with reference to FIG.
In the second embodiment, the output current value of the battery simulator 10 is calculated from the torque and the rotation speed of the rotating load in the first embodiment. As the voltage signal S15, and the current detected by the current transformer 24 as the current signal S16 to calculate the input current of the inverter.
Therefore, the load 30 in the first embodiment is provided with the sensor shaft 33 for detecting the load torque and the rotation speed, while the voltage detector of the output of the inverter 20 and the current transformer 24 for current detection are provided. Is connected to the load 30E.
Therefore, in the first embodiment, the various data of the target battery and the characteristics of the load 30 are recorded in the setting recording function 7, whereas in the second embodiment, the setting recording function 8 records the target battery in the setting recording function 8. Various data and characteristics of the inverter 20 are recorded.
[0025]
Therefore, various data of the target battery set and recorded in the setting recording function 7 in the first embodiment and the characteristics of the load 30 are input as the battery correction signal S7, and the load current and the battery In the second embodiment, instead of the battery internal characteristic simulation function 6 for obtaining the battery drop voltage signal S4 indicating the voltage value dropped by the internal resistance, the setting recording function 8 is applied to the battery internal characteristic simulation function 16. Various data of the battery and the characteristics of the inverter 20 are input as a battery correction signal S8, a voltage signal S15 indicating the inverter output voltage and a current signal S16 indicating the inverter output current are input, and the voltage dropped by the load current and the internal resistance of the battery. Battery simulator 10 for obtaining a battery drop voltage signal S4 indicative of the value. Constitute a.
That is, in the second embodiment, instead of the above expression (1),
P = 3V _a I _a COS θ (5)
And the inverter input current I is obtained from P = VI in the equation (2).
Incidentally, V _a is the effective value of the inverter output phase voltage, I _a is the effective value of the inverter output current, theta represents the phase difference of the inverter output voltage and current.
The other operations are the same as those of the first embodiment, and the description is omitted.
[0026]
In the above description, the case where the motor and the driving function are connected to an inverter such as an electric vehicle as the load of the battery simulator has been described. However, similar and similar means may be applied to other load conditions.
That is, an output value of the load device of the battery simulator which can be easily measured is detected, and a value corresponding to the output current of the battery simulator is calculated from the characteristic conditions of the load device and the output value. It is sufficient to calculate the internal voltage drop value associated with.
In addition, the above functions may be specifically formed corresponding to the functions of the battery simulator and the control device thereof.
[0027]
【The invention's effect】
The output voltage control method and the voltage control function of the battery simulator according to the present invention have the following excellent effects because they are configured and configured as described above.
(1) Pure load power of a DC power supply (battery simulator) to which the voltage control method according to the present invention is applied can be detected stably, and a correct output current can be calculated. An output voltage is obtained.
(2) Since the output voltage control device (battery simulator) to which the voltage control function according to the present invention is applied is configured as described above, the load current can be detected stably, and the voltage control does not oscillate.
(3) When the load of the DC power supply device (battery simulator) to which the voltage control function according to the present invention is applied is an inverter using a motor as a load, the load state is detected by utilizing the characteristics of the inverter. The above effects can be reliably used.
[Brief description of the drawings]
FIG. 1 is a schematic block diagram illustrating a first embodiment in which a load device is coupled to a DC power supply (battery simulator) to which a voltage control method according to the present invention is applied.
FIG. 2 is a schematic block diagram illustrating a second embodiment in which a load device is coupled to a DC power supply (battery simulator) to which a voltage control method according to the present invention is applied.
FIG. 3 is a schematic block diagram illustrating a conventional system in which a load device is coupled to a DC power supply device (battery simulator).
[Explanation of symbols]
1: converter 2: chopper 3: output voltage control function 4: subtraction function 6: battery internal characteristic simulation function 7: setting recording function 10, 10E: DC power supply (battery simulator)
20: Inverter 30: Inverter load 31: Electric motor 32: Drive mechanism (rotary load)
33: Sensor axis S1: Command voltage signal S2: Output command signal S3: Output voltage signal (DC power supply output)
S4: Battery drop voltage signal S5: Torque signal S6: Rotation speed signal S7, S8: Battery correction signal

Claims (4)

In a DC power supply that simulates and outputs the drooping characteristics of a battery,
When the load is an inverter whose load is an electric motor,
Calculate the active load power from the inverter output voltage and inverter output current,
Calculating a voltage drop equivalent value based on the internal resistance of the target battery corresponding to the load power;
An output voltage control method for a DC power supply device that simulates and outputs drooping characteristics of a battery, wherein the calculated value is output after being reduced in pressure. In a DC power supply that simulates and outputs the drooping characteristics of a battery,
When the load is an inverter whose load is an electric motor,
Calculating the load power of the DC power supply from the output torque and rotation speed of the motor ,
Calculating a voltage drop equivalent value based on the internal resistance of the target battery corresponding to the load power;
An output voltage control method for a DC power supply device that simulates and outputs drooping characteristics of a battery, wherein the calculated value is output after being reduced in pressure. In a DC power supply that simulates and outputs the drooping characteristics of a battery,
When the load of the DC power supply is an inverter with a motor as a load,
Means for measuring the output voltage of the inverter;
Means for measuring the output current of the inverter;
An arithmetic function for calculating the effective load power of the inverter from each value and phase difference of the measured output voltage and the measured output current,
A storage function for setting and recording the internal resistance signal of the target battery;
An arithmetic function for calculating a voltage drop value of the battery from the calculated load power value and the recorded internal resistance signal of the battery;
An arithmetic function for subtracting a voltage drop value of the battery from a preset output voltage value,
An output voltage control device for a DC power supply device that simulates and outputs drooping characteristics of a battery, wherein the output is output in accordance with the calculation result . In a DC power supply that simulates and outputs the drooping characteristics of a battery,
When the load of the DC power supply is an inverter with a motor as a load,
A function of detecting the output torque of the electric motor,
Rotation speed detection function,
An arithmetic function for calculating the load power of the inverter from the detected output torque value and the rotation speed value;
A storage function for setting and recording the internal resistance signal of the target battery;
An arithmetic function for calculating a voltage drop value of the battery from the calculated load power value and the recorded internal resistance signal of the battery;
An arithmetic function for subtracting a voltage drop value of the battery from a preset output voltage value ,
An output voltage control device for a DC power supply device that simulates and outputs drooping characteristics of a battery, wherein the output is output in accordance with the calculation result .

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