Abstract: A control system and a method for an on-board battery charger (OBC) of a vehicle generate a DC link voltage instruction through a proportional integral control that regards, as an instruction, a resonance switching frequency determined by a resonance capacitance and a resonance inductance of the LLC converter and allow the switching frequency of an LLC converter to operate at the resonance frequency, thus enhancing efficiency of the OBC.

Abstract: A method of controlling an on-board charger (OBC) and an OBC system are capable of improving efficiency of the OBC by controlling a DC link voltage such that a DC-DC LLC converter of an ecofriendly vehicle always operates at a resonance frequency. The method includes: detecting a switching turn-on time of a switching unit and a conduction time of a diode, comparing the switching turn-on time with the conduction time, comparing a point of time when the switching unit is turned on with a point of time when the diode becomes conductive, determining an operating frequency region of the switching unit, and controlling a voltage of an input terminal of the LLC converter such that a switching frequency of the switching unit is in a resonance frequency region of the LLC converter according to the determined operating frequency region.

Abstract: A method for controlling a power factor correction circuit includes: sensing, by a control unit, an input signal; deriving, by the control unit, a delay correction input signal using the input signal and a previous input signal that is sensed before the input signal; and controlling, by the control unit, the power factor correction circuit using the derived delay correction input signal.

Abstract: Disclosed herein is a vehicle battery charging control system, which is capable of increasing efficiency of power delivered to an electric device and a low-voltage battery to improve fuel efficiency, by connecting a low-voltage DC-DC converter (LDC) to an AC power source instead of a high-voltage battery upon charging a low-voltage battery of a vehicle to prevent power delivery efficiency of an on-board battery charger (OBC) from being reduced.

Abstract: A method of compensating for a current sensor offset of an inverter includes: calculating a current sensor offset based on an output value of a current sensor, which detects an output current of the inverter, after a vehicle has started and before a current control of the inverter is performed; actuating the inverter to perform the current control according to the calculated current sensor offset; determining whether the inverter enters a burst mode while performing the current control; and re-calculating the current sensor offset based on the output value of the current sensor when the inverter is determined to enter the burst mode.

Abstract: A method of adjusting an output voltage sensing error of a low voltage DC-DC converter to adjust a difference between a value obtained by sensing an output voltage of a low voltage DC-DC converter and a reference value controlling the low voltage DC-DC converter, thereby improving control accuracy is provided. The method of correcting an output voltage sensing error of a low voltage DC-DC converter includes applying a test voltage to an output of the LDC by voltage application equipment, sensing a voltage of the output of the LDC by a voltage sensing circuit and adjusting by a controller a voltage reference map included in an LDC controller that outputs a voltage reference value of the LDC, based on an error between the test voltage and a voltage sensing value sensed by the voltage sensing circuit.

Abstract: An apparatus for controlling an LLC converter is provided. The apparatus includes a current controller that determines a first switching frequency control value of a switching element in the LLC converter to cause an output current detection value of the LLC converter to correspond to a predetermined output current command value. Additionally, a feedforward controller determines a second switching frequency control value for operating the switching element by applying a feedforward control value that corresponds to a ripple component included in an input voltage of the LLC converter to the first switching frequency control value.

Abstract: A method for controlling a power factor correction circuit includes: sensing, by a control unit, an input signal; deriving, by the control unit, a delay correction input signal using the input signal and a previous input signal that is sensed before the input signal; and controlling, by the control unit, the power factor correction circuit using the derived delay correction input signal.

Abstract: An apparatus and a method are provided for controlling a low DC-DC converter (LDC) in an electric vehicle by prioritizing respective controllers, connecting the controllers in series in ascending order according to priority, and determining a command voltage of the LDC on the basis of output voltages of the respective controllers. Accordingly, even when a controller with a highest priority is operating, controllers of lower priority continue operating. Thus, electrical load performance degradation caused by instantaneous overcurrent generated in state transitions is prevented.

Abstract: A method and system of controlling a charging device for vehicles are provided. The method includes sensing overcurrent in a power factor correction circuit of the charging device and turning off the power factor correction circuit upon sensing overcurrent. An output voltage of the power factor correction circuit is then increased when the number of generations of sensed overcurrent is equal to or less than a predetermined first reference value and the power factor correction circuit is turned on.

Abstract: A method of estimating a root mean square (RMS) of an alternating current (AC) voltage is provided. The system includes a rectifier configured to rectify the AC voltage and a controller configured to derive a delayed AC voltage by delaying the rectified AC voltage by a preset delay time. The controller is configured to estimate a root mean square (RMS) of the AC voltage based on the rectified AC voltage and the delayed AC voltage.

Abstract: An apparatus and a method of determining a frequency of an AC power source that more accurately determine the frequency of the AC power source connected to a vehicle are provided. The apparatus includes a rectifier that is connected to the AC power source to rectify an AC voltage input from the AC power source, a first filter connected to an output terminal of the rectifier to filter a rectified voltage output by the rectifier and a second filter connected to the output terminal of the rectifier to filter the rectified voltage output by the rectifier. Further, a frequency determination unit configured to receive the rectified voltages that pass through the first and second filters and determine a voltage frequency of the AC power source from the rectified voltage that pass through the first filter using the rectified voltage that pass through the second filter as a frequency determination level.

Abstract: A method of adjusting an output voltage sensing error of a low voltage DC-DC converter to adjust a difference between a value obtained by sensing an output voltage of a low voltage DC-DC converter and a reference value controlling the low voltage DC-DC converter, thereby improving control accuracy is provided. The method of correcting an output voltage sensing error of a low voltage DC-DC converter includes applying a test voltage to an output of the LDC by voltage application equipment, sensing a voltage of the output of the LDC by a voltage sensing circuit and adjusting by a controller a voltage reference map included in an LDC controller that outputs a voltage reference value of the LDC, based on an error between the test voltage and a voltage sensing value sensed by the voltage sensing circuit.

Abstract: A method of compensating for a current sensor offset of an inverter includes: calculating a current sensor offset based on an output value of a current sensor, which detects an output current of the inverter, after a vehicle has started and before a current control of the inverter is performed; actuating the inverter to perform the current control according to the calculated current sensor offset; determining whether the inverter enters a burst mode while performing the current control; and re-calculating the current sensor offset based on the output value of the current sensor when the inverter is determined to enter the burst mode.

Abstract: A low voltage DC-DC converter of an eco-friendly vehicle is provided. The converter includes an output current limit map applier that is configured to output an output current limit value using an output current limit map. A power controller is configured to amplify the output limit value output from the output current limit map applier to a predefined gain. Furthermore, an output limiter is configured to output the output limit value output from the power controller, and filter and output the output limit value after a predefined time lapses.

Abstract: A method and system of operating an on-board charger (OBC) for an eco-friendly vehicle are provided to improve durability and extend a lifespan of the OBC during the charging of a vehicle battery using a commercial power source. The system improves durability and extends a lifespan of the OBC including a power factor correction (PFC) part by alternately operating a first boost converter and a second boost converter of the PFC part during the charging of a battery by using a commercial power supplier (an in-cable control box (ICCB)).

Abstract: A method of estimating a junction temperature of a converter for a vehicle includes: calculating, by a vehicle controller, an IGBT power loss value of the converter using an input current and an input voltage between a battery and the converter, an output voltage output from the converter to an inverter, and a duty ratio and an IGBT characteristic value of the converter.

Abstract: A power conversion apparatus and method are provided. The apparatus includes a main battery and a power converter configured to execute a high power conversion mode that generates a high power and a low power conversion mode that generates a low power using an input power from the main battery. Additionally, an auxiliary battery is configured to receive and charge the low power and an inverter is configured to convert the high power to a driving power for driving a motor.

Abstract: The present disclosure provides a fault diagnosis method for a resolver including: receiving output signals for detecting an absolute angular position of a rotor of a motor, inputted from the resolver when the motor rotates in a state in which excitation signals are applied to the resolver; periodically sampling and reading voltage values for fault diagnosis from the received output signals inputted as voltage signals from the resolver; calculating a difference between voltage values of two output signals of the received output signals generating an angle detection signal for detecting the absolute angular position of the rotor; and determining a short circuit between an excitation signal and an output signal of the resolver by comparing the difference between the voltage values with a preset setting voltage.