Insulation monitoring device and control method therefor

A method for controlling an insulation monitoring device comprising insulation resistance disposed between an electric line of a system and a ground, the method comprising:

• applying a pulse signal having a voltage of a predetermined magnitude to the electric line;
• determining an initial sampling interval;
• calculating a sampling interval according to the determined initial sampling interval, calculating an average voltage during a sampling period according to the calculated sampling interval, and calculating an average voltage during a sampling period according to a sampling interval updated according to a first time multiple;
• detecting whether a difference between a currently calculated first average voltage and a second average voltage measured before the first average voltage is within a preset first error range;
• identifying the first average voltage as a steady-state voltage according to the applied pulse signal or updating the sampling interval by applying a different time multiple according to the difference between the first average voltage and the second average voltage, as a result of the detection;
• repeatedly performing those steps of calculating the average voltage during the sampling period according to the updated sampling interval, detecting whether the difference between the voltages is within the preset first error range until the steady-state voltage is identified, and updating the sampling interval by applying the different time multiple;
• detecting whether there is a steady-state voltage according to a pre-identified another type of pulse signal when the steady-state voltage is identified;
• identifying the steady-state voltage according to the another type of pulse signal by inverting the pulse signal to the pre-identified another type of pulse signal and re-performing the determination of the initial sampling interval and the repeatedly performing step when the pre-identified another type of pulse signal is present as a result of detecting whether there is the steady-state voltage according to the pre-identified another type of pulse signal;
• and
• calculating a value of the insulation resistance based on steady-state voltages according to different types of pulse signals when the pre-identified another type of pulse signal is present as a result of the detection of the step of detecting whether there is the steady-state voltage according to the pre-identified another type of pulse signal.

An insulation monitoring device comprising insulation resistance disposed between an electric line of a system and a ground, the device comprising:

• a signal generation unit configured to apply a pulse signal having a voltage of a predetermined magnitude to the electric line;
• a signal measurement unit connected to the ground and configured to measure a voltage of the pulse signal applied from the ground when the pulse signal applied to the electric line is applied to the ground through the insulation resistance;
• an average voltage calculation unit configured to calculate an average voltage of voltages measured by the signal measurement unit during a sampling period according to a set sampling interval;
• and
• a control unit configured to calculate a sampling interval based on an initial sampling interval and a preset time multiple, calculate an average voltage as a first average voltage during a sampling period according to the calculated sampling interval, performing a tuning process for comparing the calculated first average voltage with a second average voltage calculated before the first average voltage, and detect the second average voltage as a steady-state voltage according to whether a time elapsed from a sampling starting time point is a predetermined time or longer when the difference between the average voltages is within a preset error range, or re-performing the tuning process.

A method for controlling an insulation monitoring device comprising insulation resistance disposed between an electric line of a system and a ground, the method comprising:

• applying a pulse signal having a voltage of a predetermined magnitude to the electric line;
• determining an initial sampling interval;
• performing primary tuning of calculating a sampling interval based on the initial sampling interval and a first time multiple, calculate an average voltage as a first average voltage during a sampling period according to the calculated sampling interval, and comparing the calculated first average voltage and a second average voltage calculated before the first average voltage;
• detecting whether a difference between the first average voltage and the second average voltage is within a preset first error range as a result of the primary tuning;
• terminating the primary tuning and performing secondary tuning of calculating a sampling interval based on a preset sampling interval and a second time multiple, calculating an average voltage as a third average voltage during a sampling period according to the calculated sampling interval, and comparing the calculated third average voltage and a fourth average voltage calculated before the third average voltage;
• detecting whether a difference between the third average voltage and the fourth average voltage is within a steady voltage error range as a result of the secondary tuning;
• detecting whether a predetermined time has elapsed from a starting time point of the secondary tuning when the difference between the third average voltage and the fourth average voltage is within the steady voltage error range, to detect the third average voltage as a steady-state voltage according to the applied pulse signal when the predetermined time has elapsed;
• and
• repeatedly performing the secondary tuning when the difference between the third average voltage and the fourth average voltage exceeds the steady voltage error range as a result of the secondary tuning or when a predetermined time has not elapsed from the starting time point of the secondary tuning.

An insulation monitoring device comprising insulation resistance disposed between an electric line of a system and a ground, the device comprising:

• a signal generation unit configured to apply a pulse signal having a voltage of a predetermined magnitude to the electric line;
• a signal measurement unit connected to the ground and configured to measure a voltage of the pulse signal applied from the ground when the pulse signal applied to the electric line is applied to the ground through the insulation resistance;
• an average voltage calculation unit configured to calculate an average voltage of voltages measured by the signal measurement unit during a sampling period according to a set sampling interval;
• and
• a control unit configured to calculate a sampling interval based on an initial sampling interval and a preset time multiple, calculate an average voltage as a first average voltage during a sampling period according to the calculated sampling interval, performing a tuning process for calculating a difference between the calculated first average voltage and a second average voltage calculated before the first average voltage, and detect the first average voltage as a steady-state voltage when the difference between the average voltages satisfies a preset steady voltage error,
• wherein the control unit switches an operation state into a power saving mode for a preset idle time when the difference between the first average voltage and the second average voltage satisfies a preset error condition, and resumes a tuning process of detecting the steady-state voltage by calculating the average voltages when the idle time elapses.

A method for controlling an insulation monitoring device comprising insulation resistance disposed between an electric line of a system and a ground, the method comprising:

• applying a pulse signal having a voltage of a predetermined magnitude to the electric line;
• determining an initial sampling interval;
• performing primary tuning of calculating a sampling interval based on the initial sampling interval and a first time multiple, calculating an average voltage as a first average voltage during a sampling period according to the calculated sampling interval, and comparing the calculated first average voltage and a second average voltage calculated before the first average voltage;
• repeatedly performing the primary tuning when a difference between the first average voltage and the second average voltage exceeds a preset first error range as a result of the primary tuning;
• determining at least one reference point when the difference between the first average voltage and the second average voltage is within the first error range as the result of the primary tuning, and calculating a slope ratio based on voltage slopes according to a voltage difference between voltages according to the at least one reference point;
• calculating a time constant based on the calculated slope ratio;
• switching an operation state of the insulation monitoring device to an idle state for an idle time determined according to the calculated time constant;
• checking whether the idle time has elapsed, to switch the operation state to an active state according to a result of the check;
• performing a secondary tuning of calculating a sampling interval based on a reset initial sampling interval and a second time multiple when the operation state is switched to the active state, calculating an average voltage as a third average voltage during a sampling period according to the calculated sampling interval, and comparing the calculated third average voltage and a fourth average voltage calculated before the third average voltage;
• detecting the third average voltage as a steady-state voltage according to the applied pulse signal when the difference between the third average voltage and the fourth average voltage is within a steady voltage error range as a result of the secondary tuning;
• and
• repeatedly performing the secondary tuning when the difference between the third average voltage and the fourth average voltage exceeds the steady voltage error range as the result of the secondary tuning.