KR20030056636A - Apparatus and method for diagnosing converter to drive a switched reluctance motor - Google Patents

Abstract

PURPOSE: An apparatus for diagnosing a converter for driving a switched reluctance motor(SRM) and a method thereof are provided, which detects a damage as to a switching device of an SRM driving converter automatically in real time. CONSTITUTION: According to the apparatus for diagnosing a converter for driving a switched reluctance motor(SRM) having a plurality of switching devices, the first XOR gate(11) performs XOR operation as to an upper control signal inputted to the first switching device and an upper voltage state being output from the first switching device. The second XOR gate(12) performs XOR operation as to a lower control signal inputted to the second switching device and a lower voltage state being output from the second switching device. The first NOR gate(13) performs NOR operation as to the upper control signal and the lower control signal. A NOT gate(14) performs NOT operation as to an output of the first XOR gate. The second NOR gate(15) performs NOR operation as to an output of the first NOR gate and an output of the NOT gate. The third NOR gate(16) performs NOR operation as to an output of the second XOR gate and the output of the first NOR gate. An OR gate(17) performs OR operation as to the outputs of the second and the third NOR gate. And an alarm unit informs alarm generation as to the switching device when an output signal of the OR gate is a high signal.

Description

Diagnosis device and method of the switching reluctance motor drive converter {APPARATUS AND METHOD FOR DIAGNOSING CONVERTER TO DRIVE A SWITCHED RELUCTANCE MOTOR}

The present invention relates to a switched reluctance motor (hereinafter referred to as SRM), and more particularly, to an apparatus for diagnosing an SRM driving converter capable of automatically detecting whether a switching element of the SRM driving converter is damaged. And to a method thereof.

As is well known, an SRM is a stator consisting of a plurality of salient poles arranged at a predetermined angle in a predetermined space, a rotor disposed at regular intervals from the stator to rotate about a rotation axis, and detecting a position of the rotor. And a control means for supplying power to the winding of each phase by generating an excitation signal for each phase based on the position detecting means and the position detecting signal.

In general, an electric forklift driven by electric power generates driving power using the SRM as described above. FIG. 1 illustrates a circuit structure of a typical SRM driving converter used to drive an SRM. Drawing.

In the conventional general SRM driving converter, a control signal for controlling the driving of the SRM is applied through each of the lines L1 and L2 shown in the same drawing, and the switching elements Q1 and Q2 are based on the control signal. ) Is configured to switch the flow of current, thereby switching the drive mode of the SRM.

2A to 2B are diagrams for explaining an operation mode of the SRM according to the switching operation of each of the switching elements Q1 and Q2 illustrated in FIG. 1, and the thick solid line illustrated in each diagram represents each operation mode of the SRM. It means the flow of current according to.

First, FIG. 2A illustrates a current flow in a motoring mode, in which both an upper control signal input through a line L1 and a lower control signal input through a line L2 are ON. Operation mode in the state. FIG. 2B is a diagram illustrating current flow in the upper free wheeling mode, in which the upper control signal is ON and the lower control signal is OFF.

FIG. 2C is a diagram illustrating current flow in a lower free wheeling mode, in which an upper control signal is OFF and a lower control signal is ON, and FIG. 2D is a regeneration. A diagram showing current flow in a) mode, which means that the upper control signal and the lower control signal are both OFF.

As a result, in the SRM driving converter, each of the switching elements Q1 and Q2 operates based on the upper / lower control signals input through the respective lines L1 and L2, and thus, shown in FIGS. 2A to 2D. Each operation mode as described above is repeatedly performed.

However, such a conventional SRM driving converter does not have a self-diagnostic function for the switching elements Q1 and Q2 described above, and thus, a user cannot easily detect whether the converter is damaged or not. In addition, there is a problem in that excessive maintenance time is required in case of failure of the equipment due to the switching element of the converter.

Accordingly, the present invention has been made to solve the above problems of the prior art, and provides an apparatus and method for diagnosing an SRM drive converter capable of automatically detecting in real time whether a switching element of the SRM drive converter is damaged in real time. Its purpose is to.

The present invention according to one aspect for achieving the above object,

A diagnostic apparatus for an SRM driving converter having a plurality of switching elements, comprising: a first XOR gate for performing an XOR operation on an upper control signal input to a first switching element and an upper voltage state output from the first switching element; A second XOR gate performing an XOR operation on a lower control signal input to a second switching element and a lower voltage state output from the second switching element; A first NOR gate performing a NOR operation on the upper control signal and the lower control signal; A NOT gate that performs an negation operation on the output of the first XOR gate; A second NOR gate performing a NOR operation on an output of the first NOR gate and an output of the NOT gate; A third NOR gate performing a NOR operation on the output of the second XOR gate and the output of the first NOR gate; An OR gate performing an OR operation on the outputs of the second NOR gate and the third NOR gate; When the output signal of the OR gate is a high signal (High) provides a diagnostic device of the SRM drive converter including an alarm means for notifying the occurrence of an error for the switching element.

The present invention according to another aspect for achieving the above object,

A diagnostic method for an SRM driving converter having a plurality of switching elements, the diagnostic method comprising: an upper control signal input to a first switching element and an XOR logic value of 0 for an upper voltage state output from the first switching element; Diagnosis of the SRM driving converter which determines that the first and second switching devices operate normally only when the lower control signal input to the switching device and the XOR logic value 1 for the lower voltage state output from the second switching device are present. Provide a method.

1 is a diagram illustrating a circuit structure of a typical SRM driving converter.

2A to 2D are diagrams for explaining each operation mode of a general SRM driving converter.

3 is a circuit diagram of a diagnostic apparatus for a switched reluctance motor drive converter according to the present invention;

<Explanation of symbols for the main parts of the drawings>

11, 12: first and second XOR gate

13, 15 and 16: first to third NOR gates

14: NOT gate 17: OR gate

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention.

In the present invention, in the conventional SRM driving converter shown in FIG. 1, the control signal applied to each switching element Q1 and Q2 and the output voltage corresponding thereto are checked to determine whether the switching element is normally operated. That is, the operation of the SRM driving converter based on the control signal input through each of the lines (L1, L2) is to repeatedly perform the mode shown in Figures 2a to 2d described above, wherein each switching element (Q1) When Q2 is normally operating, the voltage output through each of the switching elements Q1 and Q2 also appears to be constant.

Therefore, in the present invention, the upper / lower control signals input to the switching elements Q1 and Q2 and the upper / lower voltages corresponding thereto are checked to determine whether the switching elements Q1 and Q2 normally operate.

To this end, the relationship between the upper and lower control signals input through the lines L1 and L2 and the upper and lower voltages output through the lines L3 and L4 in the state in which the switching elements Q1 and Q2 operate normally. It should be calculated, which will be described in detail below.

First, when the operation mode of the SRM driving converter shown in FIG. 1 is a motoring mode as shown in FIG. 2A, an upper control signal and a line input to the first switching element Q1 through the line L1. Since the lower control signals input to the second switching element Q2 through the L2 are all ON, the upper voltage measured at the line L3 becomes Vdc, and the lower voltage measured at the line L4 is 0V.

When the operating mode of the SRM driving converter is the upper free wheeling mode as illustrated in FIG. 2B, the upper control signal input to the first switching element Q1 through the line L1 is in an ON state. Since the lower control signal input to the second switching element Q2 through the line L2 is OFF, both the upper voltage measured at the line L3 and the lower voltage measured at the line L4 are Vdc. Becomes

On the contrary, when the operation mode of the SRM driving converter is the lower free wheeling mode as shown in FIG. 2C, the upper control signal input through the line L1 is in an OFF state, and is connected to the line L2. Since the lower control signal input is in an ON state, both the upper voltage and the lower voltage measured at the line L3 and the line L4 become 0V.

Lastly, when the operation mode of the SRM driving converter is the regeneration mode as shown in FIG. 2D, both the upper control signal input through the line L1 and the lower control signal input through the line L2 are turned off. In the OFF state, the upper voltage measured at the line L3 becomes 0 V, and the lower voltage measured at the line L4 becomes the lower voltage 4 Vdc. Here, if the duration of the regeneration mode is long and all the magnetic energy stored in the upper winding of the SRM is regenerated to the power source, the winding current becomes 0, and the upper / lower voltage becomes a floating state in which measurement is impossible.

Table 1 shows the relationship between the control signal and the output voltage according to the driving mode of the SRM.

Upper control signal ON ON OFF OFF Lower control signal ON OFF ON OFF High side voltage Vdc Vdc 0 0 → Float Lower voltage 0 Vdc 0 Vdc → Float

On the other hand, from the correlation between the upper / lower control signal and the upper / lower voltage shown in Table 1, if the upper control signal is ON, the upper voltage is Vdc, and if the upper control signal is OFF, the upper voltage is 0V. It can be seen that. This means that when the switching elements Q1 and Q2 operate normally, the XOR logic operation for the upper control signal and the upper voltage becomes zero. In addition, if the lower control signal is ON, the lower voltage is 0V, and if the lower control signal is OFF, the lower voltage is Vdc. This means that the XOR logic operation for the lower control signal and the lower voltage is always 1. It means to be.

Therefore, by continuously checking the upper and lower control signals input to the switching elements Q1 and Q2 of the SRM driving converter and the output voltages output from the switching elements Q1 and Q2, the switching elements of the SRM driving converter are checked. Real-time diagnosis of the data is possible. That is, when the result of the XOR logic operation between the upper control signal and the upper voltage is 0 and the result of the XOR logic operation between the lower control signal and the lower voltage is 1, it is determined that the switching elements Q1 and Q2 operate normally. When other logical operation results are generated, the SRM driving converter can be diagnosed by determining that the switching elements Q1 and Q2 are broken.

In more detail, the states of the upper and lower voltages according to the respective cases in which an abnormality (short or disconnection) occurs in at least one switching element among the switching elements Q1 and Q2 may be shown in Table 2 below.

State of Q1, Q2 Upper control signal ON ON OFF OFF Lower control signal ON OFF ON OFF 1st state Q1 short circuit Q2 short circuit High side voltage Vdc Vdc Vdc Lower voltage 0 0 0 2nd state Q1 short circuit Q2 normal High side voltage Vdc Vdc Vdc Lower voltage 0 Vdc 0 3rd state Q1 Normal Q2 Short High side voltage Vdc Vdc 0 Lower voltage 0 0 0 4th state Q1 disconnection Q2 disconnection High side voltage Float Float Float Lower voltage Float Float Float 5th state Q1 disconnection Q2 normal High side voltage 0 Float 0 Lower voltage 0 Float 0 6th state Q1 Normal Q2 disconnection High side voltage Vdc Vdc Float Lower voltage Vdc Vdc Float 7th state Q1 short circuit Q2 disconnection High side voltage Vdc Vdc Vdc Lower voltage Vdc Vdc Vdc 8th state Q1 disconnection Q2 short circuit High side voltage 0 0 0 Lower voltage 0 0 0

That is, Table 2 shows the upper and lower control signals according to the case (first to eighth states) in which an abnormality (short or disconnection) occurs in at least one switching element among the switching elements Q1 and Q2.

Is a diagram showing the relationship between the upper and lower voltages. The XOR logic value for inputting the upper control signal and the upper voltage and the XOR logic value for inputting the lower control signal and the lower voltage are different from those in Table 1 above. .

That is, when the switching elements Q1 and Q2 are normal, the XOR logic values for inputting the upper control signal and the upper voltage are always 0, while the first, second, fifth, seventh and seventh values of Table 2 are zero. In state 8, the XOR logic value of the upper control signal and the upper voltage is represented by 1. In addition, when the switching elements Q1 and Q2 operate normally, the XOR logic value for inputting the lower control signal and the lower voltage is always 1, while the first, third, sixth, and seventh values in Table 2 are used. And the XOR logic value of the lower control signal and the lower voltage in the eighth state is zero. Here, since the detection voltage is floating in the fourth state among the switching elements Q1 and Q2 shown in Table 2, the exact value is not known, but the voltage is fixed to an arbitrary value. The result does not occur, and therefore, whether or not the abnormality with respect to the switching elements Q1 and Q2 is sufficiently detectable.

3 is a circuit diagram of a diagnostic apparatus for an SRM driving converter according to the present invention, and illustrates a logic circuit capable of satisfying each of the conditions described with reference to Tables 1 and 2 above. That is, the diagnostic apparatus of the SRM driving converter shown in FIG. 3 uses the correlation between the upper / lower control signals and the upper / lower voltages as shown in Tables 1 and 2, respectively. , Q2) is configured to generate a low signal when it is operating normally and to generate a high signal when it is abnormal.

Referring to FIG. 3, the first XOR gate 11 illustrated in the same drawing is connected to the line L3 and the line L1 shown in FIG. 1 and output from the first switching element Q1. XOR logic operation is performed by receiving an upper control signal input to the first switching element Q1, and the second XOR gate 12 is connected to the line L4 and the line L2 shown in FIG. The XOR logic operation is performed by receiving the lower voltage output from the second switching element Q2 and the lower control signal input to the second switching element Q2. The first NOR gate 13 is connected to the lines L1 and L2 of FIG. 1 to perform NOR logic operations on the upper control signal and the lower control signal.

Meanwhile, the NOT gate 14 performs a negation operation on the logic value of the first XOR gate 11 to transmit to the second NOR gate 15, and the second NOR gate 15 is connected to the first NOR gate 13. NOR logic operation is performed on the logical value of &lt; RTI ID = 0.0 &gt; The third NOR gate 16 performs a NOR logic operation on the logic value of the second XOR gate 12 and the logic value of the first NOR gate.

Through this process, the logic values output through the second and third NOR gates 15 and 16 are finally OR-calculated through the OR gate 17, and the logic outputs through the OR gate 17. The value is the output signal of the diagnostic device according to the invention.

As a result, the diagnostic apparatus shown in FIG. 3 always outputs a low (logical value '0') signal when the switching elements Q1 and Q2 as shown in Table 1 operate normally. As illustrated, when an abnormality occurs in at least one switching element among the switching elements Q1 and Q2, a high (logical value '1') signal is always output. Therefore, by connecting a predetermined alarm means or the like to the output terminal of the OR gate 17 of the diagnostic apparatus shown in FIG.

On the other hand, Table 2 above does not describe the state of the upper and lower voltages when the upper and lower control signals are all OFF, in which case all of the states of Table 2 are floating. In this case, the output signal of the diagnostic apparatus shown in FIG. 3 becomes a low signal. That is, when both the upper and lower control signals are OFF, even if an abnormality occurs in each of the switching elements Q1 and Q2, it cannot be detected. However, the SRM driving converter is described with reference to FIGS. Since the operation mode is repeatedly performed, the next operation mode in which both the upper and lower control signals are in an ON state can detect whether the switching elements Q1 and Q2 are abnormal.

As a result, in the present invention, by comparing the upper control signal and the upper voltage, and the lower control signal and the lower voltage of the SRM driving converter continuously, it is possible to detect whether the switching elements Q1 and Q2 are damaged in real time.

FIG. 4 is a view illustrating an alarm means that can be connected to the SRM driving converter diagnostic apparatus of FIG. 3 as described above. The display capable of displaying whether the switching elements Q1 and Q2 are damaged as described above. Means are illustrated by way of example.

First, the diagnostic apparatus 10 shown in the same drawing means the converter diagnostic apparatus for driving the SRM as shown in FIG. 3, and the display unit 30 includes an LED or an LCD.

Referring to the entire operation process with reference to the drawing, the microcontroller 20 generates a PWM control signal for detecting a failure of the SRM drive converter unit 50 to transmit to the PWM generator 40, PWM generation The unit 40 generates a corresponding PWM signal based on the PWM control signal, and then applies it to the diagnostic apparatus 10 through the lines L1 and L2 shown in FIG. 3.

In addition, the PWM signal generated from the PWM generator 40 is also transmitted to the converter unit 50. The converter unit 50 detects the upper and lower voltages of each phase winding of the motor 60 in response to the PWM signal. The detected signals are provided to lines L3 and L4 of the diagnostic apparatus 10, respectively.

Therefore, the diagnostic apparatus 10 is the upper and lower voltage input to the lines L3 and L4 through the converter unit 50 and the PWM signal input to the lines L1 and L2 through the PWM generator 40 as described with reference to FIG. By comparing through the same process, it is detected whether the converter unit 50 is damaged. Then, the corresponding detection signal is notified to the microcontroller 20.

The microcontroller 20 determines whether the converter unit 50 is damaged based on the detection signal provided from the diagnostic apparatus 10. If it is determined that the converter unit 50 is damaged, the switching element Q1 of the damaged phase is damaged. , Q2) is displayed on the display unit 30 so that the user can recognize it and perform a quick action. At the same time, further damage is prevented by blocking the PWM control signal to stop the operation of the converter unit 50.

As described above, according to the present invention, the present invention has the effect of detecting in real time whether the switch element of the SRM drive converter is damaged, and in the event of an abnormality of the SRM drive converter, it is possible to quickly take measures to damage the additional drive circuit There is an effect that can prevent. In addition, there is an effect that can minimize the maintenance time in the event of failure of the equipment due to the error of the SRM drive converter.

Claims (3)

In the diagnostic device of the converter for switching Switched Reluctance Motor (SRM) having a plurality of switching elements, A first XOR gate performing an XOR operation on an upper control signal input to a first switching device and an upper voltage state output from the first switching device; A second XOR gate performing an XOR operation on a lower control signal input to a second switching element and a lower voltage state output from the second switching element; A first NOR gate performing a NOR operation on the upper control signal and the lower control signal; A NOT gate that performs an negation operation on the output of the first XOR gate; A second NOR gate performing a NOR operation on an output of the first NOR gate and an output of the NOT gate; A third NOR gate performing a NOR operation on the output of the second XOR gate and the output of the first NOR gate; An OR gate performing an OR operation on the outputs of the second NOR gate and the third NOR gate; And an alarm means for notifying an occurrence of an error for the switching element when the output signal of the OR gate is a high signal. The method of claim 1, The alarm means, A display unit for displaying an abnormality of the SRM driving converter; A PWM generator for generating the upper control signal and the lower control signal in a PWM form based on a PWM control signal and applying the same to the first and second switching devices; The PWM control signal is generated to generate the upper control signal and the lower control signal. When a high signal is output from the OR gate, the display unit is driven to indicate whether the converter is abnormal and to block the PWM control signal. Diagnosis apparatus for a converter for driving SRM characterized in that it comprises a microcontroller. In the diagnostic method for a converter for switching Switched Reluctance Motor (SRM) having a plurality of switching elements, An upper control signal input to the first switching element and an XOR logic value of 0 for the upper voltage state output from the first switching element, and a lower control signal input to the second switching element and output from the second switching element Diagnosis method of the SRM drive converter that determines that the first and the first switching element is operating normally only when the XOR logic value 1 for the lower voltage state.