Abstract: A motor drive system includes a rectifier circuit, a controller, a modulator circuit and a direct current (DC) motor. The rectifier circuit is configured to convert an alternating current (AC) voltage to a DC voltage. The controller is configured to output a control signal. The modulator circuit includes a pulse generation module, a feedback determination module, a pulse modulation module and a driving module, and is configured to generate a modulated DC driving signal based on the DC voltage and the control signal generated by the rectifier circuit and the controller. The DC motor is configured to operate in accordance with the modulated DC driving signal generated by the modulator circuit.

Abstract: To autonomously apply a bias voltage to an optical modulator according to phase angle information provided from outside in a pluggable optical module. A pluggable electric connector (11) can communicate a communication data signal and a control signal with an optical communication apparatus (92). An optical signal output unit (13) includes a Mach-Zehnder type optical modulator including a phase modulation area and outputs an optical modulation signal (LS) modulated according to the communication data signal. An optical power control unit (14) can control optical power of the optical modulation signal (LS). A pluggable optical receptor (15) can output the optical modulation signal (LS) to an optical fiber (91). A control unit (12) controls a modulation operation of the optical signal output unit (13) and the bias voltage applied to the phase modulation area. The control unit (12) determines the bias voltage applied to the phase modulation area according to phase angle information of the control signal (CON1).

Abstract: Embodiments of the present disclosure disclose a method and apparatus for constructing a quality evaluation model, an electronic device and a computer-readable storage medium. A specific implementation mode of the method comprises: acquiring samples of knowledge contents; extracting statistical features, semantic features, and image features respectively from the samples of knowledge contents; and constructing a quality evaluation model for knowledge according to the statistical features, the semantic features, and the image features. On the basis of the prior art, this implementation mode additionally uses semantic features and image features of knowledge contents to construct a more accurate quality evaluation model based on multi-dimensional features that characterize the actual quality of a knowledge, which may well discover some brief but very useful summary knowledge in an enterprise and may recommend high-quality knowledge more accurately for employees in the enterprise.

Abstract: A power value for a low-voltage AC circuit, such as low-voltage circuit breaker, is derived. A voltage between conductors of the low-voltage AC circuit is ascertained and a current of at least one conductor is ascertained by a Rogowski coil, which outputs an analog voltage that is an equivalent to the level of the electric current. The analog voltage of the Rogowski coil is integrated and then digitized, and the level of the voltage is digitized. A power value is calculated in each case from a sample value of the current and an interpolated voltage value. The interpolated voltage value is in each case ascertained from two successive sample values of the voltage such that a phase error generated by the Rogowski coil or/and the integrator is compensated for in relation to the electric current in the conductor and a phase error-free power value is ascertained.

Abstract: A wireless power transfer system is provided having a wireless transmission system that includes an input to receive input power from an input power source, a transmission antenna, and a transmission controller configured to generate wireless signals based, at least in part, on the input power, the wireless signals including wireless power signals and wireless data signals, and to transmit such wireless signals. The wireless power transfer system further includes a wireless receiver system in a wireless peripheral device, the wireless receiver system having a receiver antenna configured to receive the wireless power signals and wireless data signals via inductive coupling with the transmission antenna, as well as a receiver controller configured to determine the acceleration of the wireless peripheral device, generate a prescribed update frequency based on the detected acceleration, and transmit operational updates to the wireless transmission system at the prescribed update frequency.

Abstract: A drive control method is applicable to a drive system including a driver, a bus and a motor, the motor being directly connected to the bus in a first connection mode or connected to the driver in a second connection mode. The drive control method includes the driver feeding an electric signal to the motor through the output port and simultaneously detecting its own actual output feature; and the driver determining whether the output port is connected to the bus according to the actual output feature. Upon the output port being determined not to be connected to the bus, the driver starts the motor normally. Upon the output port being determined to be connected to the bus, the driver disconnects the output port. In addition, a corresponding drive system, a processing system and a storage medium are disclosed.

Abstract: The present disclosure relates to a motor malfunction monitoring device, and a drive motor for oilfield operations including: a signal acquisition module configured to acquire operation data of the drive motor, wherein the signal acquisition module comprises a vibration signal acquisition unit and/or an electrical signal acquisition unit, the vibration signal acquisition unit comprises one or more vibration sensors mounted at a component to be detected of the drive motor during use and provided for detecting transverse vibration and/or longitudinal vibration, and/or the electrical signal acquisition unit comprises a voltage sensor and a current sensor for detecting a voltage and a current of the drive motor, respectively; a data storage module storing therein a database of normal operation spectrums created when the drive motor runs normally; and a signal analysis module configured to extract an acquired operation data spectrum of the operation data acquired, compare the acquired operation data spectrum with

Abstract: In described examples, a measurement circuit includes an isolated power supply that generates an output signal in response to an input signal. A signal processing circuit is coupled to the isolated power supply and generates a first signal in response to a sense signal. A load manipulator circuit is coupled to the signal processing circuit and the isolated power supply. The load manipulator circuit receives the first signal. A detect circuit is coupled to the isolated power supply and generates a second signal in response to the input signal.

Abstract: There is provided a method of operating a renewable power plant that is connected to a wider power network by a bus. The method comprises: identifying a predetermined voltage condition of the renewable power plant or of the bus; controlling the renewable power plant to maintain zero reactive power exchange at the bus for a first period; calculating an average voltage level of the bus that was achieved during the first period; and controlling the renewable power plant to maintain the voltage output at a set voltage level for a second period, the set voltage level being substantially equal to the calculated average voltage level. The method ensures that voltage oscillations due to a push-pull phenomenon between a power plant controller and the power network do not upset the stability of the grid.

Abstract: A system (10) for converting power comprising a plurality of modules (14) connected in series and having each at least one DC power source. Storage devices (18) are provided with each module (14) to store power from the power source and voltage control circuitry (19) in each module (14) connects the storage device between a maximum module voltage, a minimum module voltage to create a stepwise approximation of a mains signal. A compensator unit (20) is provided in series with the modules (14) including a storage device charged by the power sources. While each of the modules (14) is supplying either its maximum or minimum voltage to the system a control unit ramps up or down the voltage between the input and output of the compensator unit (20) to follow the desired AC signal.

Abstract: A compressor system for generating compressed air for a compressed air supply system in a vehicle. The compressor system includes a brushed direct current electric motor (BDC electric motor); a compressor configured to be driven by the BDC electric motor; and a control unit for controlling the BDC electric motor and allocated to the BDC electric motor so as to delimit an operating current of the electric motor. A free-running current path is allocated to the control unit, the free-running current path being configured to delimit the operating current of the electric motor in a variable manner. A switch controller is allocated to the control unit, the switch controller being configured to specify a switched-on time period (t_ON) and/or a switched-off time period (t_OFF) for the electric motor in a variable manner.

Abstract: The disclosure relates to a method for reducing the torque ripple and noise evolution in an EC motor with single-phase feed by buffer-storing electrical energy in the EC motor, which is embodied with a power factor correction circuit (PFC) having a capacitor (Cz) at the power supply system input for a specific power supply system AC voltage UN, wherein the capacitance of the capacitor is dimensioned such that when the power supply system AC voltage UN is applied, a pulsating DC voltage is generated in a link circuit (Z), wherein the pulsating electrical energy generated as a result is stored by means of a primary regulation of the id current component as magnetic energy in the EC motor at least for a predefined time period.

Abstract: A motor starter and a method for starting an electric motor are disclosed. In an embodiment, the motor starter includes a phase gating unit and a control unit. The phase gating unit is configured to be deactivated via the control unit after an activity period of the phase gating unit has elapsed and is configured to be deactivated during operation after the activity period has elapsed.

Abstract: To autonomously apply a bias voltage to an optical modulator according to phase angle information provided from outside in a pluggable optical module. A pluggable electric connector (11) can communicate a communication data signal and a control signal with an optical communication apparatus (92). An optical signal output unit (13) includes a Mach-Zehnder type optical modulator including a phase modulation area and outputs an optical modulation signal (LS) modulated according to the communication data signal. An optical power control unit (14) can control optical power of the optical modulation signal (LS). A pluggable optical receptor (15) can output the optical modulation signal (LS) to an optical fiber (91). A control unit (12) controls a modulation operation of the optical signal output unit (13) and the bias voltage applied to the phase modulation area. The control unit (12) determines the bias voltage applied to the phase modulation area according to phase angle information of the control signal (CON1).

Abstract: A load apparatus is connected to an AC power source and is supplied with power from the AC power source. An operation state control unit controls, based on a target value about a power-source quality including either a power-source power factor of the AC power source or a power-source harmonic of the AC power source and on a present power-source quality, an operation state of the load apparatus.

Abstract: The method and apparatus described herein uses modern digital logic that is used to meet the need by controlling Switch-Mode Power System (SMPS) components to produce efficient conversion of the AC input source to a DC output load, maintain a near-unity Power Factor Control (PFC), require relatively small components for energy storage and filtering, as well as support a form of soft-start load application to a Poly-Phase AC source.

Abstract: A system and method for determining the health of a motor drive system is provided, where a motor is coupled to a common motor control and a single or plurality of other motors are coupled to the common power source. Current data corresponding to current provided to the motor is obtained via a sensor connected to an electrical input of the motor, and voltage data corresponding to a voltage provided by the common motor control is also obtained. Based on the current data and the voltage data, a motor current provided to the motor and a motor voltage to current phase shift (or power factor) are determined, and the health of the motor drive system is determined from the motor phase shift (or power factor) and the motor current.

Abstract: A system includes first and second sources configured to provide power to first and second medium-voltage direct current (MVDC) buses, respectively. The system also includes a rotating electrical machine having first and second primary windings and first and second secondary windings. Each primary winding is electrically connected to one of the first and second MVDC buses. The rotating electrical machine is configured to receive the power from the first and second MVDC buses. Each secondary winding is configured to provide output power to a pulsed load. The system further includes at least one battery or ultra-capacitor subsystem electrically connected to the rotating electrical machine. The at least one battery or ultra-capacitor subsystem is configured to receive electrical energy from and provide electrical energy to the rotating electrical machine.

Abstract: Electrical hair removal device and method for determining the time behavior of a cyclic motor process during use of the electrical hair removal device with a motor-driven hair cutting unit by measuring the motor current. Parallel to measuring the motor current, the induced voltage of the motor is measured and a timing property of the induced voltage is evaluated, wherein the duration of a time pattern in the induced voltage is analyzed as timing property of the induced voltage. A cutting activity of the electrical hair removal device during use is determined based on the evaluated timing property of the induced voltage, and a force applied onto skin during use of the electrical hair removal device is determined based on the measured motor current and, optionally, on the determined cutting activity.

Abstract: An electronic apparatus, a voltage detector, and a voltage detection method thereof are provided. The voltage detector includes a rectifying and filtering circuit, a comparison circuit, and a detection signal generator. The rectifying and filtering circuit receives an alternating current input voltage and performs a rectifying and filtering operation on the alternating current input voltage to generate a processed voltage. The comparison circuit compares the processed voltage with a reference voltage to generate a comparison signal. The detection signal generator has a first side and a second side. The first side receives the comparison signal and generates an induction signal according to the comparison signal. The second side receives the indication signal to generate a detection signal. The first side and the second side are isolated.

Abstract: A ropeless elevator system 10 includes a lane 13, 15, 17. One or more cars 20 are arranged in the lane. At least one linear motor 38, 40 is arranged along one of the lane and the one or more cars, and a magnet 50, 60 is arranged along the other of the lane and the one or more cars. The at least one magnet is responsive to the at least one linear motor. A linear motor controller 70 is operatively connected to the at least one linear motor, and a lane controller 80 is operatively connected to the linear motor controller. A back electro-motive force (EMF) module 84 is operatively connected to at least one of the linear motor controller and the lane controller. The lane controller being configured and disposed to control stopping one of the one or more cars based on a back EMF signal from the at least one linear motor determined by the EMF module.

Abstract: A system for applying maximum driving efficiency point of load includes: a motor for driving a load; an inverter for controlling the speed and the voltage of the motor; a sensor unit for measuring the magnetic flux maintaining current and the torque current of the motor; and a control unit determining the speed of the inverter and using the proportional value of the magnetic flux maintaining current and the torque current measured within a range in which the total current does not increase when the motor is driven at the determined speed. The motor inverter control system can control both motor speed and voltage to select the lowest frequency within the permissible range and at the same time control the voltage at the water head to maximize power, thereby reducing power consumption to a minimum.

Abstract: A hybrid propulsion system for an aircraft is provided that includes a turbine engine, a first electric machine assembly connected to the turbine engine, a second electric machine assembly driven by the first electric machine assembly, and multiple third electric machine assemblies driven by the first electric machine assembly, wherein the multiple third electric machines provide a thrust output to propel the aircraft.

Abstract: A method and apparatus for a pump control system. One or more embodiments of the invention include a pump controller that can perform a self-calibrating procedure, can provide precise motor speed control, can provide a limp mode before shutting down the motor when system parameters are exceeded and/or fault conditions occur, can detect fault conditions, and can store fault conditions for later retrieval.

Abstract: An apparatus for controlling a motor having a housing in which a stator and a rotor are disposed. The motor is cooled by a cooling oil in the housing. The apparatus includes a control unit configured to control the motor. The control unit has a temperature increase mode for heating the cooling oil with use of heat generated by a resistance of a coil provided in the stator.

Abstract: A hybrid propulsion system for an aircraft is provided that includes a turbine engine, a first electric machine assembly connected to the turbine engine, a second electric machine assembly driven by the first electric machine assembly, and multiple third electric machine assemblies driven by the first electric machine assembly, wherein the multiple third electric machines provide a thrust output to propel the aircraft.

Abstract: A programmable SCR Firing system that includes modules that work together to manipulate the SCR firing circuitry so that it mimics supply load power signatures. The programmable high speed SCR firing system includes a timing module, a delay module, a zero crossing module, a single phase delay module, a firing pulse delay module, a control interface, and an user interface.

Abstract: Systems and methods for controlling an induction motor are provided. In particular, data indicative of an alternating current voltage signal associated with an induction motor can be received. The alternating current voltage signal can be applied to the induction motor through a switching element coupled between a power source and the induction motor. A zero cross voltage signal can then be generated based at least in part on the data indicative of the alternating current voltage signal. A phase delay period for at least one half cycle period of the zero cross signal can then be determined. Operation of the induction motor can then be controlled by providing one or more control signals to the switching element causing the switching element to conduct current for one or more gating periods. Each gating period can be determined based at least in part on the phase delay period.

Abstract: A method for determining motional branch current in an ultrasonic transducer of an ultrasonic surgical device over multiple frequencies of a transducer drive signal. The method may comprise, at each of a plurality of frequencies of the transducer drive signal, oversampling a current and voltage of the transducer drive signal, receiving, by a processor, the current and voltage samples, and determining, by the processor, the motional branch current based on the current and voltage samples, a static capacitance of the ultrasonic transducer and the frequency of the transducer drive signal.

Abstract: A method and apparatus for a pump control system. One or more embodiments of the invention include a pump controller that can perform a self-calibrating procedure, can provide precise motor speed control, can provide a limp mode before shutting down the motor when system parameters are exceeded and/or fault conditions occur, can detect fault conditions, and can store fault conditions for later retrieval.

Abstract: A control method brakes an electric motor connected to a voltage source. The method involves, in each cycle, the supply of current to the motor, with a delay tret, at an angle ?. The method includes a sequence such that, for every n cycle, the following steps are executed: a) determining the value of a variation in the resistance of the motor during the preceding n cycles of the voltage, b) comparing the value of the variation in resistance with a threshold resistance value Rt, c) increasing in the delay tret if the value of the variation in resistance is lower than the threshold resistance value. The increase in the delay tret is executed in accordance with a gamma command, where the angle ? lies between 50° and 80°.

Abstract: The subject matter of this specification can be embodied in, among other things, a current control assembly that includes an electrical current flow path having a maximum current flow rate, a first current limiter in the electrical current flow path, the first current limiter comprising circuitry configured to adjustably restrict current flow along the electrical current flow path to a flow rate less than the maximum current flow rate in response to receipt of a first signal at a first input port, and a second current limiter in the electrical current flow path, the second current limiter arranged to interrupt the electrical current flow path in response to receipt of a second signal at a second input port.

Abstract: The present disclosure provides a power conversion apparatus and an initial charging method of the same to control a closing phase angle at the time of switching on a power source, to suppress an overvoltage of a DC voltage, and to prevent overcharge and breakage of parts caused by the overvoltage. A peak voltage value of an input voltage, a total secondary side converted winding resistance of a primary side and a secondary side of an input transformer, a total leakage inductance of the primary side and the secondary side of the input transformer, a capacitor, and a power source frequency are substituted in a mathematical expression, and a closing phase angle is varied at predetermined intervals to obtain first half-wave peak voltage values of the capacitor voltage at the closing phase angles to close a circuit breaker.

Abstract: A current measuring circuit for an electric motor provides an output indicative of the change in the current di/dt flowing in a phase of the electric motor over a measurement period of time. The circuit includes a current measurement element having a resistance; a switch which in use selectively permits transmission of a voltage dependent upon the instantaneous value of the voltage dropped across the current measurement element to a part of the circuit; and a switch controller which is adapted to operate the switch in response to timing signals supplied by the switch controller so as to define the measurement period of time.

Abstract: Disclosed herein is a system and method for determining faults in motors and drives. The system includes a motor drive that has a DC-link coupled to a power source. A controller system is configured to measure power applied to the DC-link, integrate the power over time to yield energy consumed, and to determine energy that accumulates in operation over time. The controller is further configured to detect a fault condition when the energy that accumulates in operation is less than expected based on the energy consumed.

Abstract: A compressor for commercial refrigerators comprises an electric motor having a start winding (120) and a run winding (130), in which the input terminals of the start winding (120) and the run winding (130) are connected together and to the line voltage (L), and an electronic start device to supply the start winding (120) during a starting period. The electronic start device comprises a run condenser (40) having a first terminal connected to the output terminal from the start winding (120) and a second terminal connected to the output terminal from the run winding (130), and a start capacitor (45) having a first terminal connected to the output terminal of the start winding (120).

Abstract: A direct-axis current protection method and device for a permanent magnet synchronous motor drive system. The method includes: pre-calculating the direct-axis current of the next moment according to the current voltage transmitted from an inverter to a permanent magnet synchronous motor (PMSM); comparing the direct-axis current of the next moment with a maximum protection current; if the direct-axis current of the next moment is less than the maximum protection current, continuing transmitting the current voltage to the PMSM; if the direct axis current of the next moment is greater than or equal to the maximum protection current, redistributing the voltage according to a protection direct-axis current and a protection quadrature-axis current, and transmitting the redistributed voltage to the PMSM. The direct-axis current of the next moment is tended to be normal by adjusting the voltage.

Abstract: Methods, apparatus, and systems are described that provide an improved way to monitor the state of a dispensing system and apparatus. The method begins when an activation sensor generates a signal indicating a desired dispense cycle operation in response to detecting user input, such as user hand motion in front of the sensor. The dispenser motor is energized in response to the generated signal, and a battery sensor monitors a status of the battery during a startup phase of the dispenser motor. The monitored status of the battery during the startup phase is indicative of a state (e.g., power state or operational state) of the dispensing system, and a dispenser controller determines if the system can complete the desired dispense cycle operation based upon the monitored status and reacts to control the system accordingly, e.g., aborting a dispense cycle or allowing the dispense cycle to initiate.

Abstract: A method of operating a refrigeration system that receives power from an electrical grid includes selectively operating at least one component of the refrigeration system in a first state. The method includes selectively detecting a fault event of the electrical grid in response to a concurrent (i) increase in amount of current drawn by the component and (ii) decrease in voltage of power received by the component. The method includes, in response to detecting the fault event, switching the component from the first state to a second state. The component consumes less power in the second state than in the first state. The method includes determining a first delay period. The method includes identifying a conclusion of the fault event. The method includes, in response to the conclusion of the fault event, waiting for the first delay period before switching the component back to the first state.

Abstract: A circuit for driving a motor of a compressor includes a microcontroller, which includes an op-amp, a comparator, a first serial interface, and a first dedicated pin. The op-amp amplifies a value indicating current in a power factor correction converter, which includes a power switch. The comparator asserts a comparison signal in response to the amplified value exceeding a reference value. The comparison signal is output on the first dedicated pin. A programmable logic device (PLD) includes a second serial interface in communication with the first serial interface and a second dedicated pin. The comparison signal is received on the second dedicated pin and the PLD receives control messages from the microcontroller via the second serial interface. The PLD sets a value in an off-time register based on a control message from the microcontroller. The PLD controls the power switch according to the comparison signal and the off-time register.

Abstract: Monitoring thermal conditions of an electric motor using current signals from power supplied to the motor is disclosed herein. The current signals may be used to calculate composite current values which may be used to calculate slip. The slip may be used to provide thermal monitoring and protection to the electric motor. Slip may be calculated using only values from the stator of the electric motor for providing thermal monitoring and protection to electric motors where rotor measurements are not available.

Abstract: The present disclosure illustrates a power converter electrically connected between an external power supply and an electronic device. The electronic device has a first power-inputted terminal. The power converter includes a capacitor, a switch and an inrush-current-limit circuit. The capacitor is electrically connected to the external power supply. The switch has an input terminal electrically connected to an output terminal of the capacitor, and an output terminal electrically connected to the first power-inputted terminal A first voltage detector has an output terminal electrically connected to the switch and configured to detect an output voltage of the capacitor. When the first voltage detector detects that an input voltage of the switch is higher than a first preset voltage, the switch is set in a conductive status.

Abstract: A system includes a converter for powering a synchronous electric machine to which it is connected by cables, an insulating device and a mechanism for short-circuiting phases of the machine. The system includes primary detectors for detecting an overcurrent in the converter and a securing device able to open the insulating device when receiving a primary detection signal emitted by the primary detector. The system also includes secondary detectors able to detect a short-circuit downstream from the insulating device and to emit a secondary detection signal toward the securing device, the latter actuating the closing of the mechanism for short-circuiting as long as they have already received a primary detection signal having led to the opening of the insulating device.

Abstract: The present invention discloses a frequency-variable golden beauty bar, the frequency-variation golden beauty bar includes a beauty bar body, and a circuit board arranged in the said the beauty bar body, wherein, the circuit board includes: a control module, configured to convert a voltage variation into a frequency variation; an enable module, configured to receive a signal of the frequency variation and control a motor rotating speed; the control module connects to the enable module. The frequency-variable golden beauty bar as provided in the present invention, makes it possible to adjust an adjustable potentiometer through a knob on a tail part, and decide the voltage variation of the adjustable potentiometer through an MCU chip, then convert it into frequency variation, followed by controlling the vibration frequency of the motor through a high frequency MOS transistor, thus achieves the frequency variation of the beauty bar.

Abstract: A method for generating a challenge-response pair in an electric machine as a basis for an identification or authentication is described, the electric machine having a stator and a rotor, a first alternating voltage between two points of a first defined point pair of the electric machine being applied as a challenge, which causes an induction in the electric machine, a variable dependent on the caused induction being determined as a response. The first alternating voltage has a frequency which is higher than the working frequency of the electric machine.

Abstract: When a control device determines, based on a sampling number in one period of a target modulation factor waveform, that the sampling number is less than a predetermined value in a case where a two-phase modulation scheme is selected and the target rotation number increases, the control device switches a modulation scheme from the two-phase modulation scheme to a three-phase modulation scheme.

Abstract: A method of controlling an electric machine, the method comprising storing a plurality of power maps, each power map comprising control values for driving the electric machine at different power, and selecting a power map in response to an input signal. Additionally, a control system for an electric machine, and a product incorporating the control system and electric machine.

Abstract: A control system for a machine having a power source configured to provide power, a number of implements including a work implement, configured to provide operations, and a number of power transmitting paths configurable to selectively make power available to the implements to perform operations. The control system may include a control arrangement configured to regulate the power source to provide a first level of available power, to configure a first power transmitting path to make a percentage A1 of said first level of power available to provide a first operation, and to configure a second power transmitting path to make a percentage A2 of said first level of power available to provide a second operation, at least the second operation being a work operation.

Abstract: A device is provided that integrates a plurality of inductors in parallel. The device includes a plurality of windings and a magnetic core structure. A number of the windings corresponds to a number of the inductors. The magnetic core structure includes a plurality of windows, wherein each window includes at least two windings coupled with each other. When a phase difference of the voltage phases is smaller than a predetermined value, voltage phases of two terminals of any two of the windings within the same window are substantially the same.

Abstract: The invention relates to a method and an electrical converter of an elevator. In the method a controller of the electrical converter determines a first reactive power produced by a smoothing filter using pre-determined information on impedance of the smoothing filter. The controller may also receive information on a second reactive power from a remote node over a communication channel, the second reactive power being produced to a grid. The controller adds the first reactive power and the second reactive power to yield a total reactive power. The controller requests the electrical converter to make a plurality of compensative connections in the converter matrix to compensate the first reactive power or the total reactive power.