A method and apparatus for an active discharge of an X-capacitor are provided. A sensor signal, indicative of a voltage at the capacitor, is compared with a lower and upper threshold values. A first value of a smaller one of the lower and upper threshold values is increased to a first new value that is greater than a second value of a larger one of the lower and upper threshold values in response to a first control signal indicating the sensor signal is greater than the upper and lower threshold values. A third value of the greater one of the lower and upper threshold values is decreased to a second new value that is less than the value of the larger one of the lower and upper threshold values in response to a second control signal indicating the sensor signal is less than the upper and lower threshold values.

A radio frequency (RF) power detector is disclosed. The RF power detector includes an envelope detector having an RF signal terminal and a current mode terminal, wherein the envelope detector is configured to detect peak voltages of an RF signal at the RF signal terminal. Further included is a detector current mirror having a first mirror branch coupled to the current mode terminal and a second mirror branch configured to create a detector current that is proportional to a branch current through the first mirror branch in response to peak voltages detected by the envelope detector.

A vehicle includes an electric power source, a load configured to be supplied electric power from the electric power source, a relay provided between the electric power source and the load, and a processor. The processor is configured to control the relay to a conductive state based on a predetermined drive instruction. The processor is configured to acquire a value of current flowing through the relay and a value of voltage applied to the relay after a predetermined amount of time elapses following conduction of the relay based on the drive instruction. The processor is configured to transmit the value of the current and the value of the voltage that are acquired to an external of the vehicle.

A method for detecting a loss or an undervoltage condition of phase of an electric converter unit, wherein the method comprises: determining an extremum value, such as a maximum and/or a minimum value, of a phase voltage of the electric converter unit for at least one fundamental period of the phase voltage, and comparing the extremum value to a first threshold value, and if, based on the comparison, a first threshold criterion related to the first threshold value is satisfied, then determining the loss or the undervoltage condition of phase.

A method for detecting a loss or an undervoltage condition of phase of an electric converter unit, wherein the method comprises: determining an extremum value, such as a maximum and/or a minimum value, of a phase voltage of the electric converter unit for at least one fundamental period of the phase voltage, and comparing the extremum value to a first threshold value, and if, based on the comparison, a first threshold criterion related to the first threshold value is satisfied, then determining the loss or the undervoltage condition of phase.

A peak-detector circuit may include a first input terminal for providing a first input voltage, a first rectifying element with an anode connected to the first input terminal, a first capacitor with a first electrode connected to a cathode of the first rectifying element, a first terminal coupled to the first electrode of the first capacitor, a second rectifying element with a cathode connected to the first input terminal, a second capacitor, a first switch coupling an anode of the second rectifying element to a first electrode of the second capacitor, and a second terminal coupled to the first electrode of the second capacitor.

A peak-detector circuit may include a first input terminal for providing a first input voltage, a first rectifying element with an anode connected to the first input terminal, a first capacitor with a first electrode connected to a cathode of the first rectifying element, a first terminal coupled to the first electrode of the first capacitor, a second rectifying element with a cathode connected to the first input terminal, a second capacitor, a first switch coupling an anode of the second rectifying element to a first electrode of the second capacitor, and a second terminal coupled to the first electrode of the second capacitor.

A startup control method for a DC/DC converter is used for starting the DC/DC converter with energy transferred from a low-voltage side to a high-voltage side, and includes: determining a duty cycle or a frequency of a driving signal based on at least a voltage spike reference value and a voltage spike measurement value of a power switch at the low-voltage side; and outputting the driving signal to the power switch, thereby controlling the on and off of the power switch. The startup control method for a DC/DC converter of the disclosure can improve a reverse charging power of the converter to the maximum extent and reduce the time needed for charging a bus capacitor during a reverse startup process while ensuring voltage stress on the power switch not to exceed a limit.

A startup control method for a DC/DC converter is used for starting the DC/DC converter with energy transferred from a low-voltage side to a high-voltage side, and includes: determining a duty cycle or a frequency of a driving signal based on at least a voltage spike reference value and a voltage spike measurement value of a power switch at the low-voltage side; and outputting the driving signal to the power switch, thereby controlling the on and off of the power switch. The startup control method for a DC/DC converter of the disclosure can improve a reverse charging power of the converter to the maximum extent and reduce the time needed for charging a bus capacitor during a reverse startup process while ensuring voltage stress on the power switch not to exceed a limit.

A method for detecting power oscillation in an electric power grid, wherein the method comprises: integrating a filtered signal on a first interval, the filtered signal being associated with the electric power grid; based on the integration of the filtered signal on the first interval, determining a positive half-period area of the filtered signal and a negative half-period area of the filtered signal, one of the positive half-period area and negative half-period area being immediately subsequent to the other one; and determining that a power oscillation in the electric power grid is detected if the following two conditions are met: a sum of the positive half-period area of the filtered signal and the negative half-period area of the filtered signal is below a first threshold; and the absolute value of one of the positive half-period area and negative half-period area is above a second threshold.