Abstract: Technologies for controlling forced oscillations in electrical power grids include a processing unit and a phasor measurement unit and a control device coupled to a power grid. The processing unit receives a measurement indicative of active power in the power grid from the phasor measurement unit and determines a frequency of a forced oscillation active in the power grid based on the measurement. The processing unit injects a corrective signal with the control device into the power grid. The processing unit determines a corrective phase and a corrective amplitude in response to injecting the corrective signal. The processing unit continues to inject the corrective signal with the corrective phase and the corrective amplitude. The control device may be a static VAR compensator, a synchronous generator, a static synchronous compensator, a synchronous condenser, an electric storage device, or a solar power plant. Other embodiments are described and claimed.

Abstract: A phase correction apparatus includes an inductor joined to a series capacitor to produce phase-corrected output having a load voltage and a load current. A phase detector is joined to the series capacitor and has a phase angle output proportional to a phase angle between the voltage and current. Logic circuitry or a processor is joined to receive the phase angle output and provide switch control value outputs to switches connected to the logic circuitry. A bank of parallel capacitors are joined to the switches. The switch control value outputs activate joined parallel capacitors to adjust reactance provided to the phase-corrected output to produce an adjusted output. In a further embodiment parallel capacitors are iterated to produce the adjusted output.

Abstract: Described herein are methods and systems for detection and notification of electrical power outages and power quality. A sensor coupled to a circuit transmits a keepalive packet to a server. The sensor detects an input signal generated by electrical activity. The sensor generates an output signal based upon the input signal. The sensor monitors the output signal. During a clock cycle, the sensor determines whether a rising edge occurred and transmits a fault packet to the server when the rising edge occurred prior to a predetermined clock value or when no rising edge occurred. The server receives the fault packet from the sensor and listens for keepalive packets. The server transmits a power outage notification when no keepalive packets are received for at least a defined time period after the fault packet is received. The server transmits a power restoration notification when one or more keepalive packets are subsequently received.

Abstract: This application discloses a phase alignment circuit and method of a receive end, and a receive end, where the phase alignment circuit and method of a receive end. The receive end is located on the electric vehicle. The circuit includes: a phase measurement circuit and a controller. The controller is configured to: use, as an actual phase shift angle, a result obtained by subtracting the phase difference from a preset phase shift angle, and control a phase of a bridge arm voltage of the rectifier to lag behind the phase of the input current fundamental component by the actual phase shift angle. The controller outputs a drive signal for a controllable switching transistor of the rectifier by using the actual phase shift angle. Because a lagging phase caused due to filtering is compensated for, precision of synchronization between the bridge arm voltage and the input current can be increased.

Abstract: A lightning strike probability-based coordinated power control method for an energy storage system and a load adjusts output power of an energy storage system and a regulatable load based on a real-time predicted lightning strike probability. This reduces a correlation between a power grid in a lightning region and an external power grid, minimizes impact of a lightning strike if any on the external power grid, and decreases an economic loss due to the lightning strike in the lightning region. The present disclosure establishes a relationship between the output power of the energy storage system, the regulated power of the regulatable load, and a lightning strike probability in a same region, and then regulates the power of the energy storage system and the regulatable load in real time based on the lightning strike probability.

Abstract: A capacitor bank controller may obtain voltage and current measurements while the capacitor bank is disconnected from the power line. Further, the capacitor bank controller may obtain voltage and current measurements while the capacitor bank is connected to the power line. The capacitor bank controller may determine the size of the capacitor bank based on impedances from the voltage and current measurements while the capacitor bank is connected and disconnected.

Abstract: A control module controls impedance injection units (IIUs) to form multiple connection configurations in sequence. Each connection configuration has one IIU, or multiple IIUs in series, parallel or combination of series and parallel. The connection configurations of IIUs are coupled to a high-voltage transmission line. The control module and the IIUs generate rectangular impedance injection waveforms. When the waveforms are combined and injected to the high-voltage transmission line, this produces a pseudo-sinusoidal waveform.

Abstract: An electrical luminaire receives an AC supply as well as an auxiliary power supply. A power converter converts the AC power to supply a lighting element. A power factor associated with the AC supply is used as a control input for selecting an amount of power to be supplied from the two supplies. This enables the overall power factor to be controlled, for example to avoid financial penalties associated with the use of the AC supply with low power factor.

Abstract: Systems and methods may be used to determine fault types and/or directions even during a loss of potential by receiving, at one or more processors, an indication of a pre-fault power flow direction for a power delivery system. The one or more processors then determine a fault direction during a fault for the power delivery system using current vector angles and the pre-fault power flow direction.

Abstract: One example provides a power quality improvement system for an electrical power distribution system including a parameter measurement module to measure a power factor of the electrical power distribution system, a number of capacitor steps selectively connectable to the electrical power distribution system, and a number of harmonic filters connected to the electrical power distribution system, wherein a number and size of each capacitor step and a type of the harmonic filters are based on a load profile of the electrical power distribution system. A controller monitors a status of the harmonic filters and automatically connects or disconnects selected capacitor steps from the electrical power distribution to maintain the measured power factor at a set-point power factor, where a delay before connecting or disconnecting each selected capacitor step is based on a load stability factor of the electrical power distribution system, the load stability factor based on the load profile.

Abstract: A power conversion device includes: a power converter circuit which converts a direct-current power, output from a decentralized power supply, into an alternating-current power, and outputs the alternating-current power to a power distribution grid; a voltage target value generation unit which removes a high-frequency variation from a root mean square of a voltage detected by a voltage detection unit to generate a voltage target value; a correction unit which corrects the voltage target value when the correction unit detects that the automatic voltage regulator has performed an action; and a command unit which, if the voltage at the point of interconnection detected by the voltage detection unit deviates from a voltage control deadband referenced to the voltage target value, commands the power converter circuit to output a reactive power based on a magnitude of the deviated amount of voltage.

Abstract: An apparatus for coupling power systems, in particular a DC system, for example a motor vehicle electrical system, with a single-phase AC system or a further DC system, the apparatus including a non-inverting DC-DC converter and an inverting DC-DC converter, each having a first input and/or output and a second input and/or output, the first input and/or output of the first DC-DC converter being connected in series to a first converter valve to form a first series circuit, and the first input and/or output of the second DC-DC converter being connected in series to a second converter valve to form a second series circuit, the first and second series circuits being connected in parallel, and the second inputs and/or outputs of the DC-DC converters being connected in parallel and the terminals of the parallel circuit of the series circuits being connected to a first input and/or output of the apparatus.

Abstract: The present disclosure relates to controlling a capacitor bank using current measurements from different current sensors depending on the power flow direction. For example, the system may perform capacitor bank control operations using current measurements from a first current sensor coupled to the power line between an initial source and the capacitor bank when power is flowing in a first power flow direction on the power line. The system may determine that power flow on the power line has changed from flowing in the first power flow direction to flowing in a second power flow direction from an updated source, different from the initial source. The system may, upon detecting the change in the power flow direction perform control operations of the capacitor bank using current measurements from a second current sensor between an updated source and the capacitor bank.

Abstract: A switch-mode power supply includes a pair of input terminals for receiving an alternating current (AC) or direct current (DC) voltage input from an input power source, a pair of output terminals for supplying a direct current (DC) voltage output to a load, and at least four switches coupled in a three-level LLC circuit arrangement between the pair of input terminals and the pair of output terminals. The power supply also includes a voltage doubler power factor correction (PFC) circuit coupled between the pair of input terminals and the three-level LLC circuit, and a control circuit coupled to operate the at least four switches to supply the DC voltage output to the load.

Abstract: In a three-phase, four-wire electrical distribution system, a zig-zag transformer and at least one Cascade Multilevel Modular Inverter (CMMI) is coupled between the distribution system and the neutral. A controller modulates the states of the H-bridges in the CMMI to build an AC waveform. The voltage is chosen by the controller in order to control an equivalent impedance that draws an appropriate neutral current through the zig-zag transformer. This neutral current is generally chosen to cancel the neutral current sensed in the line. In other embodiments, the chosen neutral current may be based on a remotely sensed imbalance, rather than on a local value, determined by the power utility as a critical load point in the system. The desired injection current is then translated by the controller into a desired zero-sequence reactive impedance, based on measurement of the local terminal voltage, allowing the controller to regulate the current without generating or consuming real power.

Abstract: The invention relates to a method for impressing an electrical alternating signal in an electrochemical energy supply device (1) by means of a control device (2), in which method a coupling capacitor (Ck) is connected in series between the control device (2) and the energy supply device (1) during the duration of the signal impression operation comprising the following steps which are executed by the control device (2): a) outputting an output signal (Sout) corresponding to the alternating signal to be impressed, for impression into the energy supply device (1), wherein the output signal (Sout) is determined based on at least one setpoint (Sset), which is set by the control device (2), of the alternating signal to be impressed; b) detecting an actual signal (Sact) which corresponds to the output signal and which is applied to the energy supply device, c) comparing the actual signal (Sact) with the setpoint (Sset) of the alternating signal to be impressed and d) controlling the output signal (Sout) in order t

Abstract: In a three-phase, four-wire electrical distribution system, a zig-zag transformer and at least one Cascade Multilevel Modular Inverter (CMMI) is coupled between the distribution system and the neutral. A controller modulates the states of the H-bridges in the CMMI to build an AC waveform. The voltage is chosen by the controller in order to control an equivalent impedance that draws an appropriate neutral current through the transformer. This neutral current is generally chosen to cancel the neutral current sensed in the line. The chosen neutral current may be based on a remotely sensed imbalance, rather than on a local value, determined by the power utility as a critical load point in the system. The desired injection current is then translated by the controller into a desired zero-sequence reactive impedance, based on measurement of the local terminal voltage, allowing the controller to regulate the current without generating or consuming real power.

Abstract: Provided is an apparatus and method for controlling a circuit breaker for a static synchronous compensator (STATCOM) such that the circuit breaker installed in a branch line for the STATCOM is operated according to the current control characteristics of the STATCOM, the apparatus including: a transformer protector for detecting the differential current between primary current and secondary current of a transformer connected in series to the circuit breaker in the branch line, and controlling the opening/closing of the circuit breaker; and a STATCOM controller for controlling an operation of the STATCOM, wherein the STATCOM controller outputs, to the transformer protector, an opening suspension signal for suspending the opening of the circuit breaker when overvoltage occurring in the STATCOM is detected, and the transformer protector suspends output of a circuit breaker opening signal to the circuit breaker according to the received opening suspension signal.

Abstract: Systems and implementations for inductance tuning systems that are configured to operate in a wide range of frequencies are provided herein. The subject matter described herein can in some embodiments include an inductance tuning system including at least one inductor connected to a first terminal, the at least one inductor comprising of a plurality of inductive elements that are substantially magnetically coupled to each other, wherein spacing between the inductive elements are substantially less than diameters of the windings. At least one capacitor can be connected between one or more of the plurality of inductive elements and a second terminal.

Abstract: In some examples, a device comprises a capacitor a bidirectional inverting buck-boost converter coupled to the capacitor and configured to couple to multiple loads and to a voltage source, wherein the bidirectional inverting buck-boost converter is configured to: compare a voltage across the capacitor with a reference voltage; and based on the comparison, facilitate converting a dissipation current flowing from one of the multiple loads into a recycling current.

Abstract: The disclosure discloses an absorption circuit which is coupled to a switching power supply, wherein the absorption circuit comprises: a switching power supply voltage spike suppression circuit for changing a voltage spike of the switching power supply into a desired voltage spike, an energy storage circuit which is coupled to the switching power supply voltage spike suppression circuit and used for storing the spike voltage that is suppressed, and a release circuit which is coupled to the energy storage circuit and used for, when the voltage stored by the energy storage circuit is higher than the output voltage of the switching power supply, releasing the energy which is stored by the energy storage circuit and higher than the output voltage to the output terminal of the switching power supply. The disclosure further discloses a corresponding switching power supply and a liquid crystal display driving circuit.

Abstract: A method for operating an electrical switching device and an electrical switching device are disclosed. In order to ensure reliable operation of an electrical switching device having parallel switching paths allocated to a phase, which have lower switching capacity in comparison to conventional parallel switching paths, the zero current crossings in the phase are detected and at least one switching mechanism, operatively connected to the switching paths, is actuated so that all parallel switching paths allocated to the phase open within a window of time which is in the phase relative to the zero current crossings.

Abstract: Control circuits and methods to operate a switch of a DC-DC converter, including an output circuit to turn the switch off to control a peak inductor current in a given switching control cycle, and a modulation circuit to implement transition mode (TM) or continuous conduction mode (CCM) operation for a given switching control cycle by causing the output circuit to turn the switch on in response to an earlier one of a first signal, that represents an inductor current of the DC-DC converter, decreasing to a reference voltage that represents a zero crossing of the inductor current for the TM operation or the first signal decreasing to a valley reference signal that represents a non-zero value of the inductor current for the CCM operation.

Abstract: A control device for a static var compensator (SVC) includes: a monitoring control unit configured to generate an error presence/absence signal based on a control signal inputted from a system controller; a valve signal processing unit configured to generate a valve state signal based on databack signals respectively inputted from a plurality of valves; a CPU control unit configured to generate a state information signal based on the error presence/absence signal and the valve state signal; and a firing signal output control unit configured to generate a firing signal according to the state information signal.

Abstract: A dc link module for a power circuit comprising a first connector for connecting to a first power conversion circuit, a second connector for connecting to a second power conversion circuit, wherein the second power conversion circuit is connected to a load circuit arranged to at least intermittently operate as a power source to the power circuit, at least one dc link capacitors arranged between said first connector and said second connector for processing a voltage signal received at said first connector or said second connector, and at least one voltage compensation circuits arranged between said first connector and said second connector, said one or more voltage compensation circuits arranged to generate a voltage signal to compensate an ac ripple component in a dc voltage signal appearing across the at least one dc link capacitor.

Abstract: In various embodiments, a method for operating a sensor is provided. The method includes intermittently generating an operating current in the sensor, generating a reactive current in the sensor when the operating current is not generated, and not generating the reactive current when the operating current is generated. A value of the reactive current is the same or approximately the same as a value of the operating current.

Abstract: A control device controls a switching converter having an input alternating supply voltage and a regulated direct voltage at the output terminal. The converter comprises a switch and the control device is adapted to control the on time period and the off time period of said switch for each cycle. The control device has a first input signal representative of the current flowing through at least one element of the converter and comprises a zero crossing detector adapted to detect at least one pair of first and second zero crossings of said first signal for each switching cycle, said second zero crossing immediately following the first zero crossing and occurring in opposite direction with respect to the first zero crossing. The control device comprises a synchronizer adapted to synchronize the start of the on period with each second zero crossing of said first signal.

Abstract: An apparatus for reducing a magnetic unidirectional flux component in the core of a transformer with at least three legs, in particular a three-phase transformer having at least one compensation winding per transformer leg, wherein the compensation windings are magnetically coupled to the core of the transformer, where two compensation windings are provided per leg, the first compensation windings of a leg are each electrically connected together in a first delta connection, in each case the second compensation windings of a leg are each electrically connected together in a second delta connection, the compensation windings of at least one leg have different numbers of windings, and where at least one switching unit is arranged in series with the compensation windings for phase angle control.

Abstract: Systems, methods, and devices for monitoring one or more capacitor banks are presented herein. One concept of the present disclosure is directed to a method of monitoring at least one capacitor bank having a plurality of steps. The method includes: receiving measurements indicative of voltages and/or currents on electrical lines coupled to the steps of the capacitor bank by corresponding contactors; receiving information indicative of the respective statuses of the contactors; timestamping the measurements and contactor status information; storing the timestamped measurements with corresponding timestamped contactor status information; determining a rate of change of a parameter indicative of or derived from at least the measurements associated with at least one of the steps in the capacitor bank; comparing the determined rate of change with a baseline rate of change to produce a deviation; determining if the deviation satisfies a criterion; and, if so, indicating the deviation satisfied the criterion.

Abstract: Flicker values to be expected may be determined and achieve a high probability from suitable state and operating variables which are acquired during the first minutes in the initial smelting phase. In this way, flicker can effectively be reduced and kept below predefined limiting values. This is in particular suitable during steel production using electric arc furnaces.

Abstract: The present disclosure relates to a reactive power compensation system including a reactive power compensation unit for measuring compensate reactive power, an impedance measurement unit for measuring an impedance value of each of a plurality of loads, and a learning control unit for controlling the reactive power compensation unit based on the measured impedance value.

Abstract: A control apparatus in a static VAR compensator (SVC) system includes a plurality of current supply units for supplying phase currents configuring three-phase current of a power system, a plurality of current sensors for measuring the phase currents, and a controller for determining whether unbalance occurs in the three-phase current based on the phase currents, calculating an error corresponding to the unbalance according to the phase currents if unbalance occurs, and individually controlling at least one of the plurality of current supply units so as to compensate for the error.

Abstract: A direct electric heating (DEH) system for heating a subsea pipeline is provided. The DEH system includes a subsea power cable adapted to be coupled to a three phase electric power source. The DEH system further includes two or more subsea DEH modules. Each subsea module of the two or more subsea DEH modules is provided for heating a different pipeline section of the subsea pipeline.

Abstract: An electronic magnetic bearing controller for controlling the position of a rotor of an electrical machine supported by an active magnetic bearing the position of which being measured by at least one inductive position sensor having an inductive coil, comprising an automatic reactive power compensation device for automatically compensating the reactive power consumed by the inductive position sensor.

Abstract: A polyphase power dispatching system and a polyphase power dispatching method are provided. The polyphase power dispatching system includes an electric meter, a single-phase electricity storage module, a switch and a control circuit. The electric meter can measure transmission statuses of power transmission lines of a polyphase power line group. The common terminal of the switch is connected to the single-phase electricity storage module. The selection terminals of the switch are connected to the power transmission lines in a one-to-one manner. The control circuit is connected to the electric meter and the switch. The control circuit can correspondingly control the switch based on the transmission status of each power transmission line, so that the switch selectively connects the single-phase electricity storage module to one of the power transmission lines.

Abstract: The present invention provides coordinated control methods of generator and SVC for improving power plant active power throughput and controller thereof. The method comprises: measuring the required input parameters for the generator and SVC control; judging the system topology and the control mode of SVC to determine the operation mode; and calculating the control reference based on the operation mode to control the generator and/or SVC. The proposed methods and coordinated controllers enable the SVC to share the required reactive power output of the power plant, convert the generator into “unity-power-factor-generator”, and therefore extend the active power output capability of the power plant.

Abstract: The present disclosure relates to a reactive power compensation system includes a first measurement unit, a second measurement unit, a reactive power compensation unit, and a controller. The first measurement unit measures impedance of each of at least one load. The second measurement unit measures a voltage and current provided to the at least one load. The reactive power compensation unit compensates the leading reactive power or the lagging reactive power. The controller monitors a change of the impedance in real time, checks a change of the voltage or current according to the change of the impedance, and controls the reactive power compensation unit according to a result of the check to compensate the leading reactive power or the lagging reactive power.

Abstract: A method is performed in a control device for controlling a power compensation arrangement including a voltage source converter and one or more power compensation branches, each power compensation branch including a thyristor controlled reactor, a thyristor switched reactor or a thyristor controlled capacitor. The voltage source converter and the one or more power compensation branches are connected to a same busbar. The method includes: detecting a request in an electrical power system to which the power compensation arrangement is connected; determining, based on the request, a need for reactive power supply to the electrical power system; providing reactive power by means of the voltage source converter and/or by one or more of the power compensation branches; and compensating, by means of the voltage source converter, any disturbances caused by the power compensation branches when providing the reactive power to the electrical power system. Corresponding devices are also disclosed.

Abstract: There are provided methods, devices, and systems relating to discharging thyristor-switched capacitors. For example, there is provided a method for discharging a first capacitor, a second capacitor, and a third capacitor. Each of the capacitors is coupled to respective phases of a transmission line. The first capacitor and the third capacitor are each coupled to their respective phase of the transmission line via a pair of anti-parallel thyristors, and the second capacitor is coupled directly to another phase of the transmission line with no thyristors therebetween. The method can include determining whether an angle of a voltage on the transmission line is within a threshold angle. Further, the method can include discharging the first, second, and third capacitors when the angle is within a threshold angle and the threshold angle is any value from a predetermined set of threshold angles.

Abstract: An autonomous breaker can apply a current through a high impedance source to a bus coupled to either end of a breaker in order to measure an impedance of the bus. The status of the bus can be determined from the measurement. Based on the determined status, a fault detection procedure can be selected and implemented to determine if a fault exists on the bus. When the fault detection procedure has been implemented and no fault has been detected, the breaker can close, and thus couple the bus to another bus.

Abstract: A communication apparatus comprises a close proximity wireless communication unit which is able to perform close proximity wireless communication with an external apparatus; a power control unit which starts control of power supply of the communication apparatus when the close proximity wireless communication unit receives electromagnetic waves from the external apparatus; and a control unit which executes shutdown processing for reducing power to each block controlled by the power control unit, wherein when the shutdown processing is executed, the control unit disables the close proximity wireless communication unit before start of the shutdown processing.

Abstract: The invention provides a method and system for precisely measuring AC power and detecting load impedance using a precise analog front-end, zero-crossing detectors, and a phase detection system capable of extracting precise phase information from the sensed voltage and current measurements. More particularly, the invention provides an apparatus, comprising a transmit circuit configured to generate a wireless field via an antenna for transferring charging power to a receiver device, for determining a phase difference between a first signal and a second signal. The apparatus further comprises a phase detection circuit to output a phase signal indicating a duration of a phase offset between a time-varying voltage and a time-varying current of the transmit circuit. The apparatus further comprises a capacitor configured to receive a variable current from a current source for the duration of the phase offset between the time-varying voltage and a time-varying current.

Abstract: There is provided a method of stabilizing the voltage and reducing power losses in an electric network having a flow of live current and a flow of reactive power, the method comprising reducing the flow of live current by controlling the flow of reactive power within the network. There is also provided an electric network node having a first load point and a second load point, the second load point being at a lower load level than the first load point, the node comprising a reactive power absorber at the first load point and a reactive power generator at the lower load point.

Abstract: There is provided a communication apparatus comprising an antenna. A communication unit is able to use external power that is generated by receiving a signal from an external apparatus via the antenna, thereby transmitting a response to the signal that is received from the external apparatus to the external apparatus. A deactivation unit deactivates, in a case where the external power is generated by receiving the signal from the external apparatus via the antenna, supply of the external power from the antenna to the communication unit. A control unit performs control so as to interrupt deactivation of supply of the external power from the antenna to the communication unit by the deactivation unit.

Abstract: Disclosed are various embodiments of power source redundancy in a power supply for a rack mounted computing device. The power supply includes a plurality of AC power converters configured to receive power from corresponding power sources. A first AC power converter provides DC power to a common DC bus of the power supply. A second AC power converter provides DC power to the common DC bus in response to a change in the voltage level provided by the first AC power converter.

Abstract: A converter circuit and related technique for providing high power density power conversion includes a reconfigurable switched capacitor transformation stage coupled to a magnetic converter (or regulation) stage. The circuits and techniques achieve high performance over a wide input voltage range or a wide output voltage range. The converter can be used, for example, to power logic devices in portable battery operated devices.

Abstract: A method for controlling output energy of a power system includes following steps: Using a controlling unit to detect a phase offset between voltage and current of an AC power outputted from the power system. When the power system enters an energy-storage cycle, the controlling unit makes a power conversion unit output the AC power having a first preset power factor and store a partial energy of an AC grid in an energy-storage unit when the AC power is in a reactive power area. When the power system enters an energy-release cycle, the controlling unit makes the power conversion unit output the AC power having a second preset power factor and release the energy stored in the energy-storage unit, wherein an average value of the power factor in the energy-storage cycle and the energy-release cycle is the same as a preset average power factor.

Abstract: The invention relates to a device for influencing reactive power flows in multi-phase alternating current systems comprising a plurality of thyristor-controlled or thyristor-switched coil branches, each of which comprises a first partial coil and a second partial coil, and a first partial coil and a second partial coil respectively form a structurally independent coil subassembly. The essential feature is that the inductance factor of the first partial coil is specifically dimensioned so as to be at least 10% greater than the inductance factor of the second partial coil and the second partial coil in a coil subassembly is disposed structurally above the first partial coil or the second partial coil is disposed structurally in a core region of the first partial coil.

Abstract: A method for managing power in a transmitter to wirelessly transmit the power to a receiver. The method includes transmitting AC power through a resonance frequency band to the receiver using a transmission resonant coil, transmitting a state information of the transmitter including information related to the number of receivers that can be supported by the transmitter through out-of-band communication having a specific frequency band which is different from the resonance frequency band, receiving a state information of the receiver including information related to a rectified DC power detected by the receiver through rectification of the AC power from the receiver through the out-of-band communication and adjusting the AC power to transmit to the receiver based on the information related to the rectified DC power.

Abstract: Disclosed are a wireless power receiver and a method of managing the same. The wireless power receiver to wirelessly receive power from a wireless power transmitter and transmit the power to a load includes a receiving unit to receive AC power from the wireless power transmitter that receives power from a power supply device, a rectifying unit to rectify the received AC power to DC power, and a power managing unit to manage the power transmitted to the load based on the rectified DC power.