JP2003066078A - Capacitor testing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To further precisely calculate the internal resistance or electrostatic capacity of the capacitor bank of a drive source without having an influence on the operation of a power output device. SOLUTION: A control unit 30 switching controls the switching element of an inverter circuit 12 so that a prescribed wattless current for outputting no torque from a motor 16 is applied to each phase coil of the motor 16 when the torque command T* is 0, and capacitor banks 11a-11c are serially connected. At this time, taking the initial voltage V0 before starting of switching control, starting voltage V1 just after starting, terminal voltage V2 just before ending of switching control after the lapse of a prescribed time T, and discharge current I from a power source unit 11 in each capacitor bank 11a-11c as inputs, the internal resistance R (V0-V1/I) and the electrostatic capacity C (I.T/(V1-V2) are calculated on the basis of them.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a capacitor inspection device, and more particularly, to a power source composed of a capacitor bank capable of exchanging power and power from the capacitor bank converted into multi-phase AC power by switching a switching element. The present invention relates to a capacitor inspection device that inspects the capacitor bank in a power output device that includes an inverter circuit that can output the electric power and an electric motor that is rotationally driven by the output polyphase AC power.

[0002]

2. Description of the Related Art Conventionally, as a capacitor inspection device of this type, between the terminals of the capacitor when the motor (load) is not electrically connected to the capacitor serving as the drive power source of the motor mounted on the hybrid vehicle. In addition to measuring the voltage as the initial voltage, the voltage between the terminals of the capacitor and the output current when the motor is electrically connected are measured as the load voltage and the load current, and the internal resistance of the capacitor is calculated based on these, and the motor's internal resistance is calculated. The voltage between the terminals of the capacitor at the start of driving and the voltage between the terminals of the capacitor at the end of driving the motor are measured as the start voltage and the end voltage, respectively, and the integrated value of the drive power of the capacitor during the period from the start to the end of the drive is calculated. However, a method of calculating the capacitance of the capacitor based on these has been proposed (Japanese Patent Laid-Open No. 20-200200). Such as 0-13910 JP). In this device, the internal resistance and the electrostatic capacitance, which are the factors for evaluating the performance of the capacitor, are measured and reflected in the driving control of the hybrid vehicle.

[0003]

However, in such a device, there is a possibility that a large error may be included in the measurement of the internal resistance and the capacitance of the capacitor, especially the capacitance. When a capacitor is used as a motor drive power supply, the output current and terminal voltage of the capacitor fluctuate greatly as the motor is driven (driving a hybrid vehicle). This is based on the fact that an error is included in the result and a large error is included in the integrated value such as the final integrated value of the driving power of the capacitor.

The capacitor inspection device of the present invention is intended to measure the internal resistance and capacitance of a capacitor bank used as a power source of a power output device more accurately without affecting the operation of the power output device. Let's do it. Also,
INDUSTRIAL APPLICABILITY The capacitor inspection device of the present invention can measure the internal resistance and electrostatic capacity of each of a plurality of capacitor banks used as a power source of a power output device more easily and accurately without affecting the operation of the power output device. Is one of the purposes.

[0005]

Means for Solving the Problem and Its Function / Effect The capacitor inspection apparatus of the present invention employs the following means in order to achieve at least a part of the above objects.

The capacitor inspection apparatus of the present invention includes a power source having a capacitor bank capable of exchanging electric power, an inverter circuit capable of converting the electric power from the power source into multi-phase AC power by switching a switching element and outputting the AC power.
A capacitor inspection device for inspecting the capacitor bank in a power output device comprising a motor driven to rotate by the output polyphase AC power, wherein when the torque command of the motor is substantially constant, Switching control means for switching-controlling a switching element of the inverter circuit so that a predetermined inspection current is applied to the electric motor while maintaining the output torque substantially constant, and a discharge current of the capacitor bank accompanying the switching control. And a resistance-capacity calculating means for calculating an internal resistance or an electrostatic capacity of the capacitor bank based on the voltage across the terminals of the capacitor bank.

In the capacitor inspection apparatus of the present invention, the switching control means applies a predetermined inspection current to the electric motor while maintaining the output torque from the electric motor constant when the torque command of the electric motor is substantially constant. Thus, the switching element of the inverter circuit is switching-controlled, and the resistance-capacitance calculating means calculates the internal resistance or the electrostatic capacity of the capacitor bank based on the discharge current and the terminal voltage of the capacitor bank associated with this switching control. Thus, the discharge for inspection from the capacitor bank can be controlled without causing the motor to output an unexpected torque, so that the internal resistance and the capacitance of the capacitor bank can be measured more accurately.

In such a capacitor inspection apparatus of the present invention, the switching control means maintains the output torque from the electric motor at substantially zero and maintains the predetermined inspection current when the torque command of the electric motor is substantially zero. It may be a means for controlling the switching of the switching element of the inverter circuit so as to be applied to each phase coil of the electric motor. By doing this, when the torque command is substantially zero, the discharge for inspection from the capacitor bank can be controlled without outputting the torque from the electric motor, and the internal resistance and capacitance of the capacitor bank can be more accurately determined. It can be calculated.

Further, in the capacitor inspection device of the present invention, the switching control means is means for controlling the switching of the switching element of the inverter circuit so that a reactive current is applied to the electric motor as the predetermined inspection current. Can also be

Further, in the capacitor inspecting apparatus of the present invention, the resistance / capacitance calculating means is configured so that the discharge current of the capacitor bank and the discharge start of the capacitor bank immediately before and after the discharge start or immediately before the discharge end and the discharge due to the switching control. The internal resistance of the capacitor bank is calculated based on the terminal voltage immediately after the termination, and the integrated value of the discharge current between the predetermined two points within the discharge period of the capacitor bank and the terminal voltage at the predetermined two points. Or a means for calculating the capacitance based on the discharge energy between two predetermined points within the discharge period of the capacitor bank and the voltage between the terminals at the predetermined two points. Can also be

Further, in the capacitor inspection apparatus of the present invention, the power source comprises a plurality of capacitor banks and switching means capable of switching between a series connection and a parallel connection of the plurality of capacitor banks, and the switching control means comprises:
A means for controlling switching of the switching element of the inverter circuit so that the predetermined inspection current is applied to the electric motor when the plurality of capacitor banks are switched to the state of series connection by the switching means,
The resistance-capacity calculating means calculates an internal resistance or a capacitance of each of the plurality of capacitor banks based on a discharge current of the power supply associated with the switching control and a voltage between terminals of the capacitor banks connected in series. It can also be a means to do. In this way, since the discharge currents in each capacitor bank are all the same, it is not necessary to detect the discharge current for each capacitor bank, and it is easier to determine each discharge current based on the discharge current of the power supply and the terminal voltage of each capacitor bank. It is possible to calculate the internal resistance and capacitance of the capacitor bank.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of the present invention will be described with reference to examples. FIG. 1 shows a capacitor bank 11a.
11c as the power supply unit 11, the power output device 10 is a capacitor inspection device 20 according to an embodiment of the present invention.
It is a block diagram which shows the outline of a structure at the time of applying. First,
A power output device 10 including the capacitor banks 11a to 11c as the power supply unit 11 will be described. The power output device 10 is mounted, for example, in a vehicle such as a hybrid vehicle or an electric vehicle that uses a motor as a power source.

As shown in the figure, this power output device 10 converts the electric power from the power supply unit 11 into a three-phase alternating current suitable for driving the motor 16 and supplies it to the motor 16. The capacitor inspecting apparatus 20 of the embodiment measures the internal resistance and the electrostatic capacitance of the plurality of capacitor banks 11a to 11c that form the power supply unit 11.

Capacitor bank 11 of power supply unit 11
Each of a to 11c is configured as one or a plurality of capacitors (for example, electric double layer capacitors) connected in series and parallel. The power supply unit 11 is provided with switches SW1 to SW3 capable of switching between series connection and parallel connection of the capacitor banks 11a to 11c. That is, when the switches SW1 and SW2 are turned on and the switch SW3 is turned off, the capacitors 11b and 11
c is connected in parallel, and switches SW1 and SW
When 2 is turned off and the switch SW3 is turned on, the capacitor banks 11a to 11c are connected in series. This is because when the capacitor is used as a power source for driving the motor 16, the voltage between the terminals of the capacitor, that is, the potential difference between the positive electrode bus 13 and the negative electrode bus 14 of the inverter circuit 12 fluctuates greatly as power is supplied. Is based on. Therefore, when the potential difference between the positive electrode bus 13 and the negative electrode bus 14 decreases as the capacitor banks 11a to 11c are discharged, the parallel connection is switched to the series connection state to increase the potential difference, and conversely the capacitor banks 11a to 11c.
When the potential difference between the positive electrode busbar 13 and the negative electrode busbar 14 increases as the battery 11c is charged, the potential difference between the positive electrode busbar 13 and the negative electrode busbar 14 is reduced by switching from serial connection to parallel connection and decreasing the potential difference. It can be kept within a predetermined range, and stable power can be supplied to the motor 16.

The inverter circuit 12 is composed of six transistors and six diodes. The six transistors include a positive bus 13 and a negative bus 14, respectively.
Two pairs are arranged on the source side and the sink side with respect to and, and a three-phase coil (u
Each of vw) is connected. Therefore, if the ratio of the on-time of the paired transistors is controlled while the potential difference acts on the positive electrode bus 13 and the negative electrode bus 14, a rotating magnetic field is formed in the three-phase coil of the motor 16, and the motor 16 is rotated.
Can be driven to rotate. The inverter circuit 1
A smoothing capacitor 15 for smoothing is provided on the positive electrode busbar 13 and the negative electrode busbar 14 of No. 2.

The motor 16 is configured as a generator motor capable of generating power, for example, a synchronous generator motor capable of generating power, which is composed of a rotor having a permanent magnet attached to the outer surface thereof and a stator having a three-phase coil wound thereon. ing. The rotation shaft of the motor 16 is the output shaft of the power output device 10, and power is output from this output shaft. For example, the power output device 1
When 0 is mounted on the vehicle, the rotating shaft of the motor 16 is directly or indirectly connected to the axle of the wheel. Further, since the motor 16 is configured as a generator motor, if power is input to the rotating shaft of the motor 16, the motor 16 can generate power.

Next, a capacitor inspecting device 20 of an embodiment for measuring the internal resistance and electrostatic capacitance of each of the capacitor banks 11a to 11c in the power output device 10 will be described. As shown in FIG. 1, the capacitor inspecting apparatus 20 of the embodiment is a voltage sensor 2 that is mounted between the terminals of each of the capacitor banks 11a to 11c and detects the voltage between the terminals.
2a to 22c, a current sensor 26 that is attached to the positive electrode bus 13 and detects a discharge current from the power supply unit 11,
The control unit 30 controls the entire device including the power output device 10 and calculates the internal resistance and capacitance of each of the capacitor banks 11a to 11c based on the input of a signal from each sensor.

The control unit 30 is configured as a microprocessor centered on a CPU 32, and is provided with a ROM 34 for storing a processing program, a RAM 36 for temporarily storing data, and an input / output port (not shown). . The control unit 30 includes voltage sensors 22a ...
Each of the capacitor banks 11a to 1 detected by 22c
1c between the terminals voltage Va-Vc, the voltage V from the voltage sensor 24 attached to the positive electrode bus 13 and the negative electrode bus 14, and the power supply unit 11 detected by the current sensor 26.
From the current sensor 28a to 28c attached to each phase of the three-phase coil of the motor 16, and the rotation angle sensor 29 attached to the rotating shaft of the motor 16. The rotation angle θ, a command value for driving the motor 16 and the like are input via the input port. In addition, from the control unit 30, the inverter circuit 1
A switching control signal for controlling on / off of the second transistor is output through the output port. Note that any one of the current sensors 28a to 28c attached to each phase of the three-phase coil of the motor 16 can be omitted.

The operation of the capacitor inspecting apparatus 20 of the embodiment thus constructed, particularly, the capacitor banks 11a to 1
A process of calculating the internal resistance and the electrostatic capacitance of 1c will be described. FIG. 2 is a flowchart showing an example of a capacitor inspection processing routine executed by the control unit 30 of the capacitor inspection device 20. This routine is repeatedly executed every predetermined time.

When the capacitor inspection processing routine is executed, the CPU 32 of the control unit 30 first starts the motor 1
The torque command T * of 6 is input (step S100), and it is determined whether the input torque command T * is approximately 0 (step S102). If the torque command T * is substantially 0, it is determined whether it is continuous for a predetermined time (step S104). If it is continuous, the switch SW is switched.
The states of 1 to SW3 are input (step S106), and the capacitor banks 11b and 11c (capacitor bank 11a) are input.
To 11c) are connected in series (step S108). As a result of this determination, when it is determined that the capacitor banks 11a to 11c are connected in series, a process of calculating the internal resistance and the capacitance of each of the capacitor banks 11a to 11c is executed (step S
110) This routine ends. In step S102, the torque command T * is not substantially 0, or in step S104
In step 108, the torque command T * does not continue to have the approximate value 0 for a predetermined period, or in step 108, the capacitor banks 11a to 11
When it is determined that c are connected in parallel, this routine is terminated without doing anything. Here, the process of calculating the internal resistance and the electrostatic capacitance is executed in the state where the capacitor banks 11a to 11c are connected in series, because the same current flows in each of the capacitor banks 11a to 11c in the state of being connected in series. One current sensor 26 for detecting the current to calculate the internal resistance and electrostatic capacity of each of the capacitor banks 11a to 11c, and the capacitor banks 11a to 11c.
Voltage sensors 22a-2 for detecting the voltage across each terminal of
2c, that is, each capacitor bank 11a
It is based on the fact that it is not necessary to provide a current sensor for each ~ 11c.

Next, the process of calculating the internal resistance and capacitance of the capacitor banks 11a to 11c in step S110 will be described. This process is performed by executing the resistance-capacitance calculation routine of FIG. When this routine is executed, the CPU of the control unit 30
32, first, inputs the inter-terminal voltages Va to Vc of the capacitor banks 11a to 11c detected by the voltage sensors 22a to 22c as the initial voltage V0 and also supplies the phase currents Iu and Iv to the current sensors 28a to 28c. , I
Input w (step S200). Then, the motor 1
A current command I so that a reactive current that does not output torque from 6, that is, a predetermined inspection current flows only in the d-axis of the motor 16
d *, Iq * (Id * = Itest, Iq * = 0) is set (step S202), and this is subjected to two-phase / three-phase conversion to set current commands Iu *, Iv *, and Iw * for each phase ( Step S204). Then, the current commands Iu *, Iv of each phase
*, Iw * and each phase current I input in step S200
Voltage command V applied to each phase based on u, Iv, and Iw
u, Vv, Vw are calculated (step S206), and the inverter circuit 12 is based on the voltage commands Vu, Vv, Vw.
A switching control signal for driving is output (step S208). When the driving of the inverter circuit 12 is started,
Voltage sensor 22a detected at the start of driving (immediately after starting)
22 to 22c, the inter-terminal voltages Va to Vc of the capacitor banks 11a to 11c are input as the start voltage V1 and the discharge current I of the power supply unit 11 from the current sensor 26 is input.
Is input (step S210), and the inter-terminal voltages Va to Vc of the capacitor banks 11a to 11c detected after the elapse of a predetermined time T from the start of driving the inverter circuit 12 in step S208 (for example, immediately before the end of driving). Input as voltage V2 (steps S212, S21
4). Then, the internal resistance R of each of the capacitor banks 11a to 11c is calculated by the following equation (1) based on the input discharge current I, the initial voltage V0, and the start voltage V1 (step S216). In the embodiment, the inverter circuit 1
Although the internal resistance R is calculated from the initial voltage V0 before the start of driving of No. 2 and the start voltage V1 immediately after the start of driving, it is sufficient if the voltage change due to the discharge of each of the capacitor banks 11a to 11c can be detected. The internal resistance can also be calculated from the voltage immediately before the end of driving of 12 and the voltage immediately after the end of driving.

R = (V0-V1) / I (1)

Next, the discharge current I over the predetermined time T is given.
Of the capacitor banks 11a to 11 according to the following equation (2) based on the integrated value I · T of the start voltage V1 and the end voltage V2.
The electrostatic capacitance C of c is calculated (step S218), and this routine ends.

[0024] C = IT / (V1-V2) (2)

Each capacitor bank 1 thus calculated
By optimizing the switching timing of the switches SW1 to SW3 during operation of the power output device 10 by using the internal resistances and electrostatic capacitances of 1a to 11c, the power output device 10 can be a device with higher energy efficiency. Can be done.

According to the capacitor inspecting apparatus 20 of the embodiment described above, when the torque command T * of the motor 16 is approximately 0, a predetermined inspecting current is applied only to the d-axis that does not output torque from the motor 16. Since the transistor of the inverter circuit 12 is controlled to be applied to the inverter circuit 16, a substantially constant inspection current can be discharged from each of the capacitor banks 11a to 11c without causing the motor 16 to output an unexpected torque. It is possible to more accurately calculate the internal resistance and the capacitance of the capacitor banks 11a to 11c based on and the voltage across the terminals of the capacitor banks 11a to 11c. Moreover, each of the capacitor banks 11a to 11 is switched by the switches SW1 to SW3.
Since the inspection is performed in the state where c is connected in series, it is not necessary to detect the current for each of the capacitor banks 11a to 11c, and the internal resistance and the capacitance of each of the capacitor banks 11a to 11c can be calculated with a simpler configuration. You can

In the capacitor inspection device 20 of the embodiment, the integrated value I · T of the discharge current I and the start voltage V over the predetermined time T are obtained.
1 and the end voltage V2 based on each capacitor bank 11
Although the electrostatic capacitances C of a to 11c are calculated using the formula (2), each capacitor bank 11 for a predetermined time T is calculated.
It may be calculated using the following equation (3) based on the integrated value E of the supply energy (product of discharge current and terminal voltage) of a to 11c, the start voltage V1 and the end voltage V2.

C = 2E / (V2 ² -V1 ² ) (3)

In the capacitor inspection device 20 of the embodiment, the inspection is performed when the capacitor banks 11a to 11c are connected in series.
If a current sensor that detects a discharge current is provided for each of a to 11c, it is possible to perform an inspection even when connected in parallel.

In the capacitor inspection apparatus 20 of the embodiment, the power supply unit 11 is composed of a plurality of capacitor banks 11a-11.
Although it is configured to have c, the power supply unit may be configured by one capacitor bank.
In this case, the internal resistance and the electrostatic capacitance are calculated based on the discharge current detected by the current sensor 26 in FIG. 1 and the inter-terminal voltage detected by the voltage sensor 24.

In the capacitor inspection device 20 of the embodiment, when the torque command T * of the motor 16 is approximately 0, the reactive current that does not output torque from the motor 16 is the motor 16.
Switching control is performed on the transistors of the inverter circuit 12 so that each capacitor bank 1
Although the internal resistance and the electrostatic capacitance are measured based on the states of 1a to 11c, when the torque command T * of the motor 16 is substantially constant over a predetermined period, the torque of the motor 16 is substantially constant. Is output and a predetermined inspection current flows through the d-axis of the motor 16 so that the dq of the motor 16 is
It is also possible to set the current to flow through the shaft, control the switching of the transistor of the inverter circuit 12 based on the current, and perform the inspection based on the state of each of the capacitor banks 11a to 11c at this time.

In the capacitor inspecting apparatus 20 of the embodiment, an electric motor driven by three-phase alternating current is used as the motor 16, but an electric motor driven by multi-phase alternating current other than three phases may be used.

Although the embodiments of the present invention have been described with reference to the embodiments, the present invention is not limited to the embodiments of the present invention, and various embodiments are possible without departing from the gist of the present invention. Of course, it can be implemented in.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an outline of a configuration when a capacitor inspection device 20 according to an embodiment of the present invention is applied to a power output device 10 including capacitor banks 11a to 11c as a power supply unit 11.

FIG. 2 is a flowchart showing an example of a capacitor inspection processing routine executed by a control unit 30 of the capacitor inspection device 20 according to the embodiment.

FIG. 3 is a flowchart showing an example of a resistance capacitance calculation processing routine executed by a control unit 30 of the capacitor inspection device 20 of the embodiment.

[Explanation of symbols]

10 power output device, 11 power supply unit, 11a-1
1c capacitor bank, 12 inverter circuit, 13
Positive busbar, 14 Negative busbar, 15 Smoothing capacitor,
16 motors, 20 capacitor inspection devices, 22a-2
2c voltage sensor, 24 voltage sensor, 26 current sensor, 28a to 28c current sensor, 29 rotation angle sensor,
30 control unit, 32 CPU, 34 ROM, 3
6 RAM.

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2G028 AA01 BB06 BE04 CG02 CG07                       DH03 FK01 FK02                 5H007 AA17 BB06 CA01 CB02 CB05                       CC12 DB13 DC02 DC05 FA12                 5H576 AA15 BB07 CC01 DD07 EE09                       FF07 GG01 GG04 HA02 HB02                       JJ03 LL22 LL24 LL41 LL54                       MM20

Claims (5)

[Claims] 1. A power supply composed of a capacitor bank capable of exchanging power, an inverter circuit capable of converting the power from the power supply into multi-phase AC power by switching a switching element and outputting the multi-phase AC power, and the output multi-phase. A capacitor inspection device for inspecting the capacitor bank in a power output device comprising a motor driven to rotate by AC power, wherein the output torque from the motor is substantially constant when the torque command of the motor is substantially constant. A switching control means for switching-controlling a switching element of the inverter circuit so that a predetermined inspection current is applied to the electric motor while maintaining the discharge current, a discharge current of the capacitor bank associated with the switching control, and a terminal of the capacitor bank. The internal resistance or capacitance of the capacitor bank based on Capacitor testing apparatus and a resistance capacity calculating means for calculating. 2. The switching control means, when the torque command of the electric motor is substantially zero, so that a predetermined inspection current is applied to the electric motor while maintaining the output torque from the electric motor at substantially zero. The capacitor inspection device according to claim 1, which is a unit that controls switching of a switching element of the inverter circuit. 3. The capacitor inspection according to claim 1, wherein the switching control means is means for controlling switching of a switching element of the inverter circuit so that a reactive current is applied to the electric motor as the predetermined inspection current. apparatus. 4. The resistance-capacitance calculating means determines the discharge current of the capacitor bank and the inter-terminal voltage immediately before and after the start of discharge of the capacitor bank, or immediately before and after the end of discharge, and immediately after the end of discharge due to the switching control. Based on this, the internal resistance of the capacitor bank is calculated, and the capacitance is calculated based on the integrated value of the discharge current between two predetermined points within the discharge period of the capacitor bank and the terminal voltage at the two predetermined points. Or a means for calculating a capacitance based on a discharge energy between two predetermined points within a discharge period of the capacitor bank and a voltage between terminals at the predetermined two points. Capacitor inspection device. 5. The capacitor inspection device according to claim 1, wherein the power source includes a plurality of capacitor banks, and switching means capable of switching between a series connection and a parallel connection of the plurality of capacitor banks. The switching control means comprises a switching element of the inverter circuit so that the predetermined inspection current is applied to the electric motor when the plurality of capacitor banks are switched to the state of series connection by the switching means. Is a means for switching control, the resistance capacitance calculation means, the discharge current from the power supply associated with the switching control, and the terminal voltage of each of the capacitor banks connected in series A capacitor inspection device that is a means for calculating the internal resistance or capacitance of each.