A switch portion (107) is connected between a DC input/output portion (102) and an MERS (105) in such a direction that in a rectification operation, the direction of current flowing between the MERS (105) and the DC input/output portion (102) and the forward direction of a diode (DD) are the same direction. The on and off states of the MERS (105) are changed corresponding to positive and negative AC voltages. The switch portion (107) is turned on during at least part of the period in which the MERS (105) is turned on.
H02M 7/48 - Conversion of DC power input into AC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
H02M 7/12 - Conversion of AC power input into DC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
H02M 7/219 - Conversion of AC power input into DC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only in a bridge configuration
2.
ELECTRICAL POWER CONVERSION DEVICE, ELECTRICAL POWER CONVERSION CONTROL DEVICE, ELECTRICAL POWER CONVERSION METHOD, AND PROGRAM
In the present invention, an electrical power conversion device (100) is provided with the following: a first connecting section (101) that is connected to a current source (11); a second connecting section (102) that is connected to a voltage source (13); and a magnetic energy recovery switch (105) that performs either a first supply in which electrical power from the current source (11) is converted and supplied to the voltage source (13) or a second supply in which electrical power from the voltage source (13) is converted and supplied to the current source (11). The electrical power conversion device (100) is further provided with a control unit (110). The control unit (110), by changing the timing at which the thyristors (16A-16F) of the current source (11) are switched on, causes the magnetic energy recovery switch (105) to perform either the first supply or the second supply.
H02M 7/12 - Conversion of AC power input into DC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
H02M 3/155 - Conversion of DC power input into DC power output without intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
3.
SERIES RESONANT DC/DC CONVERSION DEVICE AND POWER CONVERSION METHOD
In the disclosed power conversion method, power supplied by a secondary battery (E1) is converted to first electrostatic energy by a MERS (101). Then, the first electrostatic energy is converted to magnetic energy by an inductor (Lm). Next, the magnetic energy is converted to second electrostatic energy by a MERS (102). The second electrostatic energy is supplied to a secondary battery (E2). Power is thus supplied from one secondary battery (E1) to another secondary battery (E2).
H02M 3/155 - Conversion of DC power input into DC power output without intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
4.
POWER CONVERSION DEVICE, POWER CONVERSION CONTROL DEVICE, POWER CONVERSION METHOD, AND PROGRAM
With regard to a device for supplying power from an MERS (magnetic energy regeneration switch) (100) connected to a power source (VS), the load current flowing from the MERS (100) to a load is detected by means of a current detecting unit (300a). For the purpose of forming a path to begin charging the capacitor (CM) of the MERS (100), a control unit (400) determines, on the basis of the detected load current, the timing for turning off the reverse-conducting type semiconductor switch of the MERS (100). The control unit (400) controls the maximum value of the voltage between both terminals of the capacitor (CM) by turning off the reverse-conducting type semiconductor switch of the MERS (100) at the determined target timing.
H02M 7/48 - Conversion of DC power input into AC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
H02M 3/155 - Conversion of DC power input into DC power output without intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
5.
INDUCTIVE POWER-SUPPLY SYSTEM, POWER-RECEIVING DEVICE, AND CONTROL METHOD
The disclosed inductive power-supply system (10) is configured from: a power-supply device (11) provided with an AC power source (VS), a primary coil (L1), and a series circuit; and a power-receiving device (12) provided with a secondary coil (L2), a magnetic energy regeneration switch (100), a rectifier (DB), a load (LD), and wireless control devices (201, 202). A magnetic field arises in the primary coil (L1) by means of current from the AC power source (VS) flowing in the primary coil (L1), and by means of this magnetic field, current flows in the secondary coil (L2). The wireless control devices (201, 202) control the magnetic energy regeneration switch (100) on the basis of the current flowing in the primary coil (L1).
A motor control apparatus (10) is provided with a full-bridge type MERS (100), a line path (150), a control circuit (200), and a plurality of connection switches (SWMi), and is connected between an AC power supply (VS) and a plurality of motors (Mi). Each of the connection switches (SWMi) is connected to a motor (Mi), the full-bridge type MERS (100), and the line path (150). The control circuit (200) makes the motors (Mi) soft-start one by one, and makes the motors (Mi) proceed to rated operation, by switching four reverse-conducting type semiconductor switches (SW1-SW4) that comprise the full-bridge type MERS (100), and the connection switches (SWMi).
H02P 5/74 - Arrangements specially adapted for regulating or controlling the speed or torque of two or more electric motors controlling two or more AC dynamo-electric motors
H02M 7/48 - Conversion of DC power input into AC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
7.
PROTECTED POWER CONVERSION DEVICE AND CONTROL METHOD
Provided is a protected power conversion device (1) that is connected between a DC current source (2) and an inductive load (3) and comprises a full-bridge MERS (100), a control circuit (200), and an ammeter (300). The ammeter (300) measures the current supplied to the inductive load (3). The control circuit (200) converts the power outputted from the DC current source (2) into AC power by means of four reverse-conducting semiconductor switches (SW1 to SW4) in the full-bridge MERS (100), and supplies said AC power to the inductive load (3). If a large current flows, such as due to a short-circuit fault in the inductive load (3), and the current measured by the ammeter (300) reaches or exceeds a prescribed value, the control circuit (200) turns off all of the reverse-conducting semiconductor switches (SW1 to SW4), thereby shutting off the flow of current.
H02M 7/48 - Conversion of DC power input into AC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
H02H 7/122 - Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for convertersEmergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for rectifiers for static converters or rectifiers for inverters, i.e. DC/AC converters
8.
POWER INVERTER, INDUCTION HEATER, MOTOR CONTROL DEVICE, AND POWER INVERTING METHOD
A power inverter (1) comprises a plurality of driving circuits (10i) connected in parallel with a DC power supply (2). Each of the driving circuits (10i) includes: a DC reactor (Ldci) connected to the DC power supply (2) in series; a magnetic energy regeneration switch (Bi) including a plurality of reverse conducting semiconductor switches (SWUi, SWVi, SWYi, SWXi) having DC input ends to which a series circuit of the DC power supply (2) and the DC reactor (Ldci) and a capacitor (CMi) are connected and AC output ends to which a load (LDi) is connected; and a control circuit (13i). The control circuit (13i) turns on and off the reverse conducting semiconductor switches (SWUi, SWVi) with a duty ratio of 0.5, and adjusts the duty ratio of the reverse conducting semiconductor switches (SWYi, SWXi) to 0.5 or less.
H02M 7/48 - Conversion of DC power input into AC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
H02P 27/08 - Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage using DC to AC converters or inverters with pulse width modulation
H05B 6/06 - Control, e.g. of temperature, of power
A power conversion device (1) is configured from an inductor (L) connected in series to an alternating-current power source (20) and a load (30), a full-bridge MERS (100) connected in parallel to the load (30), a control circuit (110), a current direction switching unit (200) connected in series between the inductor (L) and the load (30), and an ammeter (300). The control circuit (110) feeds back the current detected by the ammeter (300), repeatedly switches on and off one pair corresponding to the positive/negative of the output of the alternating-current power source (20), out of a pair of inverse-conductive semiconductor switches (SW2, SW3) and a pair of inverse-conductive semiconductor switches (SW1, SW4) which configure the full-bridge MERS (100), and keeps the other pair off.
H02M 5/293 - Conversion of AC power input into AC power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into DC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
10.
POWER CONVERSION DEVICE, POWER CONVERSION METHOD, AND PROGRAM
The disclosed power conversion device (1) is configured from a MERS (100) and a control means (105), and is connected in parallel between a load (300) and a series circuit comprising an AC power source (210), a resistor (R), and a reactor (L). By means of the control means (105) switching on and off a reverse-conducting semiconductor switch that configures the MERS (100), the MERS (100) increases the voltage of the output of the AC power source (210), and regulates such that the current flowing through the AC power source (210) does not exceed the rating of the AC power source (210).
H02M 7/12 - Conversion of AC power input into DC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
11.
POWER CONVERSION DEVICE AND DC-POWER/AC-POWER CONVERSION SYSTEM
The voltage waveform and current waveform of the AC power to be outputted are controlled by: varying the period of time an ON signal of a gate-control signal, which makes an inverse-electrical-connection semiconductor switch constituting a magnetic-energy regeneration switch turn ON/OFF, is to be continued, within a range of time equal to or more than the minimum time necessary for a capacitor (C) to discharge and the voltage between both ends of the capacitor (C) becomes approximately zero (V); and varying the switching frequency of the ON/OFF of the inverse-electrical-connection semiconductor switch, within a range equal to or less than the resonant frequency that is decided by the capacitance of the capacitor and the inductance of the resonant inductor (5). Furthermore, the obtainable electric power can be increased, by having a DC current supply that supplies electric power to a power conversion device, connected via a diode.
H02M 7/48 - Conversion of DC power input into AC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
12.
MAGNETIC ENERGY REGENERATION SWITCH PROVIDED WITH PROTECTION CIRCUIT
Disclosed is a magnetic energy regeneration switch composed of at least two semiconductor switches of opposite conductivity types and two capacitors. Specifically, a magnetic energy regeneration switch provided with a protection circuit and a control method for protecting a capacitor from overvoltage and short-circuit discharge and for protecting the semiconductor switches of opposite conductivity types and a load from overvoltage and overcurrent. The magnetic energy regeneration switch can be used as a controller and a current-limiter.
A magnetic energy regenerative switch section (10) includes a magnetic energy regenerative switch (MERS) (30), and a control section (40) changes the magnitude of the output voltage and the phase of the current of power passing through the magnetic energy regenerative switch section (10) by controlling the gate phase angle α of the magnetic energy regenerative switch (MERS) (30), thus compensating for a voltage drop caused by the inductive component of a load consuming that power. A modular circuit device (1) capable of replacing the components, comprises the control section (40) which can be attached removably to a joint (60), the magnetic energy regenerative switch section (10) which can be attached removably to the control section (40), and a capacitor (32), and allows power to pass therethrough. Such components as the magnetic energy regenerative switch section (10), the control section (40) and the capacitor (32) are modularized and can be attached removably. A plurality of kinds of modules are provided previously and components can be replaced on a module basis at the installation site depending on the conditions of a load such as a lighting system. When the function of a modularized component deteriorates, the module including the deteriorated component is removed and replaced, and a module which does not need replacement can be used continuously.
A power inverter (10) is a device for generating an AC power from a DC power and comprises a DC reactor (Ldc) connected in series to a DC voltage source (11); a first capacitor (CM) connected in parallel to a DC circuit consisting of the DC voltage source (11) and the DC reactor (Ldc); a full-bridge circuit that has its DC input terminals connected to the respective terminals of the first capacitor (CM) and that includes a plurality of semiconductor switches (SU, SV, SY, SX); and a second capacitor (CP) connected between AC output terminals of the full-bridge circuit. A load (LD) is also connected between the AC output terminals. A control circuit (12) supplies switching signals to the plurality of semiconductor switches. While the inductance component (L) of the load (LD) and the first and second capacitors (CM, CP) are resonating, the current flowing through the load (LD) is divided by the first and second capacitors (CM, CP).
H02M 7/48 - Conversion of DC power input into AC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
H02M 7/5387 - Conversion of DC power input into AC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters in a bridge configuration
A power inverter (1) is provided with a full-bridge circuit (10), a shunt capacitor (CP), and a control circuit (20). The control circuit (20) controls the on/off state of each inverse-conductive semiconductor switch (SW1 to SW4) at a switching frequency of not more than the resonance frequency determined by the capacitance of the shunt capacitor (CP) and the inductance of an inducible load (LD) in such a manner that when a first inverse-conductive semiconductor switch (SW1) and a fourth inverse-conductive semiconductor switch (SW4) are in the on-state, a second inverse-conductive semiconductor switch (SW2) and a third inverse-conductive semiconductor switch (SW3) are brought into the off-state, and that when the first inverse-conductive semiconductor switch (SW1) and the fourth inverse-conductive semiconductor switch (SW4) are in the off-state, the second inverse-conductive semiconductor switch (SW2) and the third inverse-conductive semiconductor switch (SW3) are brought into the on-state.
H02M 7/48 - Conversion of DC power input into AC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
H02M 7/5387 - Conversion of DC power input into AC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only, e.g. single switched pulse inverters in a bridge configuration
Provided is an AC voltage control device for adjusting the voltage of a load to be connected with an AC power source, by a convenient method. In this AC voltage control device, a magnetic energy regeneration switch having a condenser and an AC switch circuit connected in parallel is connected between the AC power source and the load. The AC switch circuit is turned ON several mS from such a timing of a zero condenser voltage as occurs twice for one current cycle, so that a condenser current is bypassed to reduce a reactance voltage thereby to adjust a load voltage.
G05F 1/445 - Regulating voltage or current wherein the variable is actually regulated by the final control device is AC using discharge tubes or semiconductor devices as final control devices semiconductor devices only being transistors in series with the load
G05F 1/12 - Regulating voltage or current wherein the variable is actually regulated by the final control device is AC
This power supply system (100) supplies electric power from a plurality of wind power generators (G21)-(G23) with big generation fluctuations to electric chargers (81)-(83) as contracted electric power consumption sources that allow a plurality of supplied electric power components to fluctuate. An electric power supply distribution means (73) distributes electric power with big fluctuations generated by the wind power generators (G21)-(G23) to each contracted electric power consumption source so as to satisfy both “a contracted short time fluctuation allowance rate” and “a contracted long time fluctuation allowance rate” that are agreed with a manager of each contracted electric power consumption source, changes a gate phase of a magnetic energy regeneration switch (MERS) (30) connected with each contracted electric power consumption source, and adjusts an electric power consumption amount of each contracted electric power consumption source, thereby carrying out “generated electric power amount following consumption”.
A prime mover system (100) comprises a heat engine (110) such as a diesel engine or the like; an electric generator (120); a rectifier (130) for rectifying an AC power; a smoothing capacitor (140) for smoothing a DC power produced by the rectifier (130); an inverter (160); and an electric motor (170). Between the electric generator (120) and the rectifier (130), there is connected a magnetic energy regeneration switch (MERS) (30) that serves as a power supply power adjusting switch. Moreover, a control part (40) changes the gate phase angle α of the magnetic energy regeneration switch (MERS) (30) in accordance with the voltage of a DC power and changes both the magnitude of the output voltage of the power supply power adjusting switch and the phase of the current thereof, thereby compensating for the voltage reduction of the AC power caused by the inductive component included in the electric generator and further adjusting the voltage of the DC power to a predetermined value.
H02M 7/06 - Conversion of AC power input into DC power output without possibility of reversal by static converters using discharge tubes without control electrode or semiconductor devices without control electrode
H02P 9/04 - Control effected upon non-electric prime mover and dependent upon electric output value of the generator
An information providing system (100) includes: a digital converter (74) which converts predetermined information to be transmitted to a digital signal; a magnetic energy regeneration switch (MERS) (30) connected in series to a DC power source (2) and an illumination lamp (60); and a control unit (40) which is connected to a magnetic energy regeneration switch (MEERS) (30) and changes frequency of high-frequency current supplied to the illumination lamp (60) by the magnetic energy regeneration switch (MERS) (30) according to the digital signal so as to rapidly control the bright/dark change of the illumination lamp (60), thereby realizing transmission of predetermined information based on the bright/dark change of the illumination lamp (60).
An object of this power converting apparatus is to stabilize the voltage by using an AC current advance control in a case of being connected to a weak-power system and to perform a maximum charging within the range of a power-receiving contract. A power conversion from AC or DC to DC and an inverse conversion are performed by using a magnetic energy regenerative switch in which a magnetic energy storage capacitor having a small capacitance is connected to a DC terminal of a bridge circuit using at least two reverse-conducting semiconductor switches. The DC parts of a plurality of secondary battery charging apparatuses each using this power converting apparatus are connected to each other by use of a common DC bus so that power can be interchanged between those secondary battery charging apparatuses.
G05F 1/56 - Regulating voltage or current wherein the variable actually regulated by the final control device is DC using semiconductor devices in series with the load as final control devices
G05F 1/00 - Automatic systems in which deviations of an electric quantity from one or more predetermined values are detected at the output of the system and fed back to a device within the system to restore the detected quantity to its predetermined value or values, i.e. retroactive systems
An illumination system (100) has a presence detection sensor (80) which detects the presence/absence of a human (M) or a vehicle (V), an MERS (30) which is connected with an AC power supply (20) and a street lamp (60), and a control part (40) which varies the luminance of the street lamp (60) by varying the output voltage and the phase of the current of the MERS (30) according to an output signal from the presence detection sensor (80). The illumination system moreover has an adjustment part (74) which adjusts the luminance variation mode of the street lamp (60).
A welding machine power supply apparatus (1) is connected between a DC power supply (2) and each of a welding rod (30) and a base material (40) and comprises an MERS (10) that converts a DC voltage outputted by the DC power supply (2) to an AC voltage; a control part (20) that controls the MERS (10); and a coil (5) used for resonation with an alternating pulse current. The MERS (10) includes at least two reverse-conducting-type semiconductor switches and a capacitor (12) that, during a current interruption, stores a circuit magnetic energy to regenerate the welding rod and the base material. The control part (20) controls the switching frequency of the MERS (10), thereby converting the DC voltage outputted by the DC power supply (2) to the AC voltage.
H02M 7/48 - Conversion of DC power input into AC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
H02M 9/00 - Conversion of DC or AC input power into surge output power
A patient's condition notification system (100) comprises a pulse monitor (80) for detecting a condition of a patient (M), a MERS (30) connected to an AC power supply (20) and an illumination lamp (60), and a controller (40) connected to the pulse monitor (80) and the MERS (30) and adjusting the brightness of the illumination lamp (60) by changing the magnitude of the output voltage and the phase of the current of the MERS (30) according to the output signal from the pulse monitor (80).
An illumination control device (100) has magnetic energy recovery switches (MERS) (30) which are each connected between an illuminating lamp (60) and an alternate voltage source (20) to adjust load power outputted from the alternate voltage source (20) to the illuminating lamp (60) to light the illuminating lamp (60), dimming control parts (70) each controlling an MERS (30), and a traffic detection sensor (80) which detects a vehicle traffic volume on the upstream sides of the illuminating lamps (60) in a vehicle traveling direction. The dimming control part (70) controls the MERS (30) to adjust the load power so that the illuminating lamp (60) comes into a standby lighting state of lighting with a luminance less than that during rated lighting and to adjust the load power so that the illuminating lamp (60) lights with a luminance not less than that in the standby lighting state according to the detection result obtained by the traffic detection sensor (80).
An information providing device (100) comprises an MERS (30) which is connected between an illumination lamp (60) having an inductive load and an AC voltage source (20) and adjusts load power which is supplied from the AC voltage source (20) to the illumination lamp (60) and lights the illumination lamp (60), a dimming control portion (70) for controlling the MERS (30), and an operation switch (80) for instructing dimming to the dimming control portion (70). The dimming control portion (70) controls the MERS (30) so that it adjusts the load power to change the luminance of the illumination lamp (60) while maintaining the lighting state of the illumination lamp (60) in response to the instruction from the operation switch (80) and provides visual information by changing the luminance of the illumination lamp (60).
G08B 5/36 - Visible signalling systems, e.g. personal calling systems, remote indication of seats occupied using electric transmissionVisible signalling systems, e.g. personal calling systems, remote indication of seats occupied using electromagnetic transmission using visible light sources
An illumination control device (100) has a first MERS (30a) which adjusts the magnitude of the voltage and the phase of the current outputted to a first system including illuminating lights (60a to 60c), a second MERS (30b) which adjusts the magnitude of the voltage and the phase of the current outputted to a second system including illuminating lights (60d to 60f), a first adjustment part (70a) and a second adjustment part (70b) which control the first MERS (30a) and the second MERS (30b)respectively, and a power factor adjustment instruction part (80) which instructs adjustment of the phase of the current and dimming. The power factor adjustment instruction part (80) adjusts the power factor of an alternate voltage source (20) by advancing the phase of the current flowing through the illuminating lights (60a to 60c) relative to that of a power voltage and by delaying the phase of the current flowing through the illuminating lights (60d to 60f) relative to that of the power voltage, and adjusts the luminances of the illuminating lights (60a to 60f) by adjusting the voltage outputted to the illuminating lights (60a to 60f).
An adaptor with a dimming function has a load power adjustment switch for adjusting load power to be supplied from a power source to an illumination lamp for lighting the illumination lamp and a dimming control part for controlling the load power adjustment switch, and is connected between a socket connected electrically with the power source and the illumination lamp. The load power adjustment switch has two or more reverse conducting type semiconductor switches and capacitors for accumulating the magnetic energy of a current when the current is interrupted and regenerates the magnetic energy to the illumination lamp. Thus, the load power adjustment switch controls the gate phase of the reverse conducting type semiconductor switches to adjust the load power to be supplied to the illumination lamp.
A PM motor driving power unit drives a three-phase PM motor by a direct current power source (1), wherein a controlling means (7) controls reverse conducting semiconductor switches (S1-S4) in pulse voltage generating means (2) so as to cause ON/OFF operations of each diagonally-positioned pair of the switches (S1-S4) to occur simultaneously, controls three-row switches in polarity switching means (5) so as to cause ON/OFF operations of the three-row switches to occur alternately at the same timing as those of the reverse conducting semiconductor switches (S1-S4) in the pulse voltage generating means (2), selects a switch in the polarity switching means (5) based on a rotational position signal, converts a direct current pulse output from the pulse voltage generating means (2) into a polarity of a three-phase alternating current, and supply it as a driving current to the PM motor (4).
H02P 27/06 - Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage using DC to AC converters or inverters
Provided is an AC voltage control device inserted between an AC power source and an induction load so as to adjust a load voltage of the induction load by a magnetic energy regenerative switch. The device reduces the voltage load on an inverse-conductive semiconductor switch and a capacitor in the magnetic energy regenerative switch and controls voltage supplied to the induction load by using a small advance amount of phase of a current supplied to the induction load.
H02M 5/293 - Conversion of AC power input into AC power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into DC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
30.
MAGNETIC ENERGY REGENERATING SWITCH HAVING PROTECTING CIRCUIT
Provided is a magnetic energy regenerating switch (MERS) comprising a voltage detecting unit for detecting the condenser voltage of the MERS so as to protect the MERS against an excessive voltage and an excessive current, and a control unit for turning on the switch of a discharge circuit connected in parallel with a condenser, when the output of the voltage detecting unit exceeds a predetermined value, thereby to discharge electric charge of the condenser. Moreover, a current detecting unit for detecting the electric current to flow through the load is inserted between an AC power source and the load, so that the duty ratio of the ON/OFF of the pulses of the gate control signal of the switch of the MERS is made less than 0.5, when the output of the current detecting unit exceeds a predetermined value, thereby to perform a current-limiting control.
H02M 7/48 - Conversion of DC power input into AC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
patents