Exciter overload current detection device

Abstract

The invention discloses an overload current detection device for an exciter. An overload current comparison section compares a current of an exciter with a reference current and outputs an overload current comparison signal. The filter outputs an overload current generation signal when the output value of the overload current comparison section maintains an overload current state value during the filtering time. The counter accumulates and counts the time at which the output value of the overload current comparison unit corresponds to the overload current state value. When the count value of the counter exceeds a threshold value, the comparator outputs an overload current generation signal.

Description

Technical Field

[0001] The present disclosure relates to an exciter overcurrent detection device, and more particularly, to an exciter overcurrent detection device for an exciter included in a motor controller. Background Art

[0002] A resolver sensor is a sensor used to measure the position of a motor's rotor. Due to their superior mechanical strength and durability compared to encoders, resolver sensors are used as position sensors for driving motors in applications requiring high-performance and high-precision drives, such as vehicles. Specifically, resolvers are designed to measure the rotation of rotating devices such as motors and engines. Resolver sensors in motor drive systems are typically used to detect the rotor's position, where frequent speed changes or precise position control are required.

[0003] To operate the resolver sensor, the motor controller may be provided with an exciter. The exciter can transmit an excitation signal to the resolver sensor. Upon receiving the excitation signal, the resolver sensor can generate a sine signal and a cosine signal based on the excitation signal and transmit the sine and cosine signals to the motor controller. The motor controller can then determine the position of the motor accordingly. Summary of the Invention

[0004] For purposes such as precise motor control and the prevention of resolver sensor failure, it is desirable to detect overcurrent in an exciter included in a motor controller. Therefore, an object of the present invention is to provide an exciter overcurrent detection device capable of highly accurate overcurrent detection even under various overcurrent conditions.

[0005] The exciter overload current detection device according to the present disclosure includes: an overload current comparison unit, configured to compare the current of the exciter with a reference current and output an overload current comparison signal; a filter, configured to output an overload current generation signal when the output value of the overload current comparison unit maintains an overload current state value during a filtering time; a counter, configured to accumulate and count the time corresponding to the output value of the overload current comparison unit and the overload current state value; and a comparator, configured to output an overload current generation signal when the count value of the counter exceeds a threshold value.

[0006] The exciter overcurrent detection device according to the present disclosure may further include an OR gate configured to receive an output of the filter and an output of the comparator to output a final overcurrent generation signal.

[0007] In the present disclosure, the counter may be configured to detect an overcurrent due to oscillation of the current of the actuator.

[0008] In the present disclosure, when a time corresponding to a set reset counter is reached, the counter may be reset.

[0009] In the present invention, the time corresponding to resetting the counter may be an integer multiple of the filtering time.

[0010] In the present invention, the filtering time may be equal to the threshold.

[0011] In the present disclosure, the filter may include a counter configured to count a time during which the output value of the overcurrent comparison section maintains the overcurrent state value.

[0012] In the present disclosure, the controller of the actuator may be configured to generate a signal to shut down the actuator according to the overload current.

[0013] In the present invention, the controller of the actuator may be configured to periodically re-execute the actuator after the actuator is turned off.

[0014] The exciter overload current detection device according to the present disclosure includes: an overload current comparison unit, configured to compare the current of the exciter with a reference current and output an overload current comparison signal; a processor; and a memory, connected to the processor and storing instructions executed by the processor, wherein, when the instructions stored in the memory are executed by the processor, the instructions enable the processor to: determine whether the output value of the overload current comparison unit maintains the overload current state value during the filtering time; accumulate the time corresponding to the output value of the overload current comparison unit and the overload current state value and determine whether the accumulated time exceeds a threshold; and determine that an overload current has occurred when the output value of the overload current comparison unit maintains the overload current state value during the filtering time, or when the accumulated time corresponding to the output value of the overload current comparison unit and the overload current state value exceeds a threshold.

[0015] According to an embodiment of the present disclosure, the exciter overload current detection device can determine whether an overload current has occurred by determining whether the overload current state of the overload current comparison result is maintained for a predetermined period of time, and further determine whether the overload current occurs due to oscillation by accumulating the counting time of the overload current state, thereby enabling accurate overload current detection even in various overload current situations. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 shows the configuration of a motor system according to an embodiment of the present disclosure;

[0017] Figure 2 shows the configuration of an exciter overload current detection device according to an embodiment of the present disclosure;

[0018] Figure 3 and Figure 4 is an exemplary diagram illustrating an overcurrent detection operation of a filter using an exciter overcurrent detection device according to an embodiment of the present disclosure; and

[0019] Figures 5 to 7 is an exemplary view illustrating an overcurrent detection operation by a counter of the exciter overcurrent detection device according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0020] Hereinafter, an exciter overload current detection device according to an embodiment of the present disclosure will be described with reference to the accompanying drawings. In this process, the thickness of the lines and the dimensions of the components in the drawings may be exaggerated for clarity and convenience. Furthermore, the following terms are defined with consideration of the functionality of the present disclosure and may vary depending on the intentions and practices of the user or operator. Therefore, the terms should be defined based on the content of the entire specification.

[0021] Figure 1 The configuration of a motor system according to an embodiment of the present disclosure is shown.

[0022] like Figure 1 As shown, the motor system includes a motor controller 1 , a resolver sensor 2 , and a motor 3 .

[0023] The motor controller 1 may include an exciter that generates an excitation signal. For reference, it should be understood that the excitation signals mentioned in this detailed description are collectively referred to as signals applied to the object, and there may be other terms such as excitation signal, stimulation signal, etc., but they will be collectively referred to as excitation signals in this detailed description.

[0024] The excitation signal generated by the exciter may be a sinusoidal signal having a constant frequency, and the exciter may include a square wave to sinusoidal converter for converting the square wave into the sinusoidal signal.

[0025] Furthermore, the excitation signal generated by the exciter may be transmitted to resolver sensor 2 . Resolver sensor 2 may be an analog angle detection sensor that uses electromagnetic induction to convert the mechanical angular displacement of motor 3 into an electrical signal. Furthermore, resolver sensor 2 may be implemented to receive the excitation signal and then modulate the excitation signal using the stator coil to generate a reflected signal (i.e., a sine wave signal and / or a cosine wave signal).

[0026] The motor controller 1 can estimate the position of the rotor of the motor 3 based on these reflected signals to control the motor. For example, the motor controller can perform operations such as motor phase / speed detection, motor torque control, regenerative braking control, etc.

[0027] Figure 2 FIG. 4 shows a configuration of an exciter overload current detection device according to an embodiment of the present disclosure, Figure 3 and Figure 4 is an exemplary diagram illustrating an overcurrent detection operation of a filter using the exciter overcurrent detection device according to an embodiment of the present disclosure, and Figures 5 to 7 is an exemplary view illustrating an overcurrent detection operation by a counter of the exciter overcurrent detection device according to an embodiment of the present disclosure.

[0028] like Figure 2 As shown, the exciter overload current detection device may include an analog block 10 and a digital block 20. The analog block 10 and the digital block 20 may be desirably included in the motor controller 1.

[0029] The analog block 10 may include an overcurrent comparison section 11. The overcurrent comparison section may include an overcurrent (OC) comparator that receives inputs of the actuator current and a reference current OCref and outputs a comparison result OC_COMP_OUT of the actuator current.

[0030] The output of the OC comparator may be set to have a high value when the driver current is greater than the reference current OCref and a low value when the driver current is less than or equal to the reference current OCref.

[0031] The current input to the OC comparator may correspond to the current value of the output signal of the actuator (i.e., the signal sent to resolver sensor 2 and the current flowing through the actuator's FET). In some embodiments, the actuator overcurrent detection device may be configured to detect whether the current flowing through other components of the actuator is an overcurrent.

[0032] Digital block 20 is a component that determines whether an actual overcurrent has occurred in the actuator based on the output signal of the OC comparator (i.e., the output value of overcurrent comparison section 11). Specifically, if the output value of overcurrent comparison section 11 temporarily becomes high due to a temporary error, such as when the current of the actuator momentarily exceeds a reference current, or when a spike or overshoot is generated in the output of overcurrent comparison section 11, it is desirable to determine that an actual overcurrent has not occurred.

[0033] The filter 21 is a component that filters such a transient overcurrent signal. The filter 21 may check whether the output value of the overcurrent comparison section 11 remains high for a predetermined period of time to determine whether an actual overcurrent has occurred.

[0034] For example, the filter 21 may include a counter (i.e., a first counter) that counts the time that the output of the overcurrent comparison unit 11 remains high. The filter 21 may be configured to output a high signal to the OR gate 25 when the counter value exceeds the filtering time set in the register 22. The counter may be configured to start counting when the output value of the overcurrent comparison unit 11 is high, and to reset when the output value of the overcurrent comparison unit 11 is low.

[0035] However, even when the current of the actuator oscillates and exceeds the reference current, the operation of the filter 21 described above can filter the output value of the overcurrent comparison section 11 to correspond to a transient overcurrent signal.

[0036] In other words, if Figure 3 and Figure 4 As shown, when the current of the exciter oscillates, the output value of the overcurrent comparison unit 11 is changed to a low state, and due to the oscillation before the filtering time is reached, the value of the counter is initialized, so that the signal is filtered and judged not to correspond to the overcurrent.

[0037] Regarding the oscillation phenomenon of the current of the exciter described above, when the circuit is short-circuited according to the simulated closed-loop characteristics, oscillation may occur from the point in time when the phase margin is zero (0), depending on the specific capacitance and inductance. When the oscillation continues for more than a predetermined time, it is desired to determine that an actual overcurrent has occurred even in this state.

[0038] The counter 23 (i.e., the second counter) of the digital block 20 may be configured to cumulatively count the time during which the output value of the overcurrent comparison unit 11 corresponds to a high state. The comparator 24 may be configured to compare the count time of the counter 23 with a threshold value set in the register 22 and output a high signal to the OR gate 25 when the count time of the counter 23 exceeds the threshold value.

[0039] like Figure 5 and Figure 6 As shown, the oscillation signal may be cumulatively counted, and when a threshold value set in register 22 is reached, it may be determined that the oscillation signal corresponds to an overload current.

[0040] In some embodiments, the threshold value set in register 22 may be the same value as the filtering time.

[0041] In addition, if Figure 7 As shown, the counter 23 may be configured to automatically reset after a time period corresponding to the reset counter set in the register 22 has elapsed. This is to prevent erroneous detection of overcurrent due to false signals.

[0042] The time corresponding to the reset counter can be configured to be set to an integer multiple of the filter time. For example, the time corresponding to the reset counter can be set to a time eight times the filter time. In this case, it can be configured to automatically set the value corresponding to the above threshold and reset counter even when the user only sets the value corresponding to the filter time in register 22.

[0043] The motor controller 1 may be configured to ultimately determine whether an overcurrent has occurred through OR logic (ie, OR gate 25 ) based on the overcurrent determination result of the filter 21 and the overcurrent determination result of the counter 23 .

[0044] The motor controller 1 may be configured to shut down the exciter when determining that an overcurrent has occurred. This operation may be configured to shut down a FET included in the exciter.

[0045] The motor controller 1 may also be configured to perform periodic automatic retry of the exciter when the exciter is turned off. That is, because the vehicle may experience a momentary short circuit that appears and then disappears in the event of an overcurrent caused by current oscillation, the motor controller 1 may be configured to retry the exciter to re-determine whether an overcurrent has occurred.

[0046] Furthermore, the operation of the digital block 20 of the exciter overcurrent detection device described above may be configured to be implemented by a processor and a memory storing instructions to be executed by the processor. In this case, when the instructions stored in the memory are executed by the processor, the instructions may cause the processor to: determine whether the output value of the overcurrent comparison unit 11 maintains the overcurrent status value (i.e., a high value) during the filtering time; accumulate the time during which the output value of the overcurrent comparison unit 11 corresponds to the overcurrent status value and determine whether the accumulated time exceeds a threshold; and determine that an overcurrent has occurred when the output value of the overcurrent comparison unit 11 maintains the overcurrent status value during the filtering time or the accumulated time during which the output value of the overcurrent comparison unit 11 corresponds to the overcurrent status value exceeds a threshold.

[0047] As described above, the exciter overload current detection device according to an embodiment of the present disclosure can determine whether an overload current has occurred by determining whether the overload current state of the overload current comparison result is maintained for a predetermined period of time, and further determine whether the overload current occurs due to oscillation by accumulatively counting the time of the overload current state.

[0048] Although the foregoing embodiments have been provided in conjunction with the accompanying drawings to illustrate the present disclosure, it will be apparent to those skilled in the art that the embodiments are given by way of illustration only and that various modifications and equivalent embodiments may be made without departing from the spirit and scope of the present disclosure. Therefore, the scope and spirit of the present disclosure should be limited only by the appended claims.

Claims

1. An exciter overload current detection device, comprising: an overcurrent comparison unit configured to compare the current of the actuator with a reference current and output an overcurrent comparison signal; a filter configured to output an overcurrent generation signal when the output value of the overcurrent comparison section maintains an overcurrent state value during a filtering time; a counter configured to cumulatively count a time during which the output value of the overcurrent comparison unit corresponds to the overcurrent state value; as well as A comparator is configured to output the overcurrent generation signal when the count value of the counter exceeds a threshold value.

2. The exciter overload current detection device according to claim 1, further comprising: An OR gate is configured to receive the output of the filter and the output of the comparator to output a final overload current generation signal.

3. The exciter overload current detection device according to claim 1, wherein: The counter is configured to detect an overcurrent due to oscillations of the current of the exciter.

4. The exciter overload current detection device according to claim 1, wherein: When the time corresponding to the set reset counter is reached, the counter is reset.

5. The exciter overload current detection device according to claim 4, wherein: The time corresponding to the reset counter is an integer multiple of the filtering time.

6. The exciter overload current detection device according to claim 1, wherein: The filtering time is equal to the threshold.

7. The exciter overload current detection device according to claim 1, wherein: The filter includes a counter configured to count a time during which the output value of the overcurrent comparison section maintains the overcurrent state value.

8. The exciter overload current detection device according to claim 1, wherein: The controller of the exciter is configured to shut down the exciter according to the overcurrent generation signal.

9. The exciter overload current detection device according to claim 8, wherein: The controller of the actuator is configured to periodically re-activate the actuator after the actuator is shut down.

10. An exciter overload current detection device, comprising: an overcurrent comparison unit configured to compare the current of the actuator with a reference current and output an overcurrent comparison signal; processor; as well as a memory connected to the processor and storing instructions to be executed by the processor, Wherein, when the instructions stored in the memory are executed by the processor, the instructions enable the processor to: determining whether the output value of the overcurrent comparison unit maintains the overcurrent state value during the filtering time; accumulating a time during which the output value of the overcurrent comparison section corresponds to the overcurrent state value and determining whether the accumulated time exceeds a threshold value; and When the output value of the overcurrent comparison section maintains the overcurrent status value during the filtering time, or when the accumulated time during which the output value of the overcurrent comparison section corresponds to the overcurrent status value exceeds the threshold, it is determined that overcurrent has occurred.

Images