CN207083020U - Dc source - Google Patents

Abstract

A kind of dc source is disclosed, such as can be used for the brake coil power supply to elevator.The dc source includes the first rectifier and the second rectifier.First ac terminal of the first rectifier can be couple to the first terminal of supply and AC network, and the second ac terminal is couple to the first ac terminal of the second rectifier.Second ac terminal of the second rectifier can be couple to the Second terminal of supply and AC network.The first DC terminal and the second DC terminal of second rectifier can provide direct current supply to load.In addition, the dc source also includes the controllable power semiconductor switch being coupled between the first DC terminal of the first rectifier and the second DC terminal.Present disclose provides the twin-stage rectifier configurations of AC, one-level is used as voltage adjustment level, and one-level is used as rectification stage.Turned on and off by what is switched in the first order, the voltage of direct current supply can be controlled.

Description

Dc source

Technical field

Circuit engineering is the utility model is related to, in particular it relates to a kind of dc source, it can be used for the brake to elevator Coil power supply.

Background technology

Traditionally, the mechanical brake in elevator is controlled using electric mechanical switch (contactor).However, this contactor exists Noise is larger in operation, and the user to elevator brings bad experience.In addition, the original such as the operating vibration due to elevator Cause, brake coil (that is, the solenoid that magnetic force is produced in brake) may be caused to occur can in earth fault, or circuit Short trouble can occur, under these failure conditions, response speed/cut-off velocity of existing electric mechanical switch is slower, easily leads Fuse is caused to be burned out.

Figure 1A shows a kind of direct current (DC) power supply for brake coil.As shown in Figure 1A, the D/C power can wrap Include rectifier G1.Rectifier G1 can receive AC input at exchange (AC) power supply terminal 101a, 101b, such as be powered from AC The AC electric power of network, rectification is carried out to the AC electric power received, then applied the D/C voltage after rectification by DC lead-out terminals To the both ends of restraining coil 109.This rectifier G1 can be full-wave rectifier, such as include four diode G1a-G1b bridge Formula rectifier.In addition, in order to suppress the factors such as the harmonic wave in AC input to meet Electro Magnetic Compatibility (EMC) requirement, can also be EMC filter networks 103 (for example, filter network that the inductance L1 and electric capacity C1 shown in Figure 1A are formed) are set at AC input. In Figure 1A circuit, in order to tackle earth fault, switch 111 (above-mentioned contactor) can be set., can when there is earth fault To block the earth-fault current of the low voltage side of brake coil 109 by turning off switch 111.Earth fault can pass through prison Electric current I1, I2 for surveying at brake coil 109 both ends is detected (for example, in case of earth fault, I1 and I2 may not phases Deng).It can be controlled by controller 115 to carry out Earth Fault Detection and switch.Further, since brake coil 109 is sense Property element, its electric current can not terminate immediately.It is standby in order to be provided when switching 111 shut-off for the electric current in brake coil 109 Routing path, can be the fly-wheel diode 113 of 109 reverse parallel connection of brake coil one.However, the height due to brake coil 109 Switch is not present in voltage side, thus can not block the earth-fault current of restraining coil high-voltage side.

As an improvement Figure 1B shows another D/C power for being used for brake coil.D/C power shown in Figure 1B With the D/C power shown in Figure 1A in terms of circuit topology it is substantially the same, but in addition in the high-voltage side of brake coil 109 Introduce another switch 117.Correspondingly, controller 115 also has the control port for controlling the switch 117.When appearance ground connection event During barrier, the earth-fault current of the low voltage side of brake coil 109 is blocked except again may be by shut-off switch 111, also The earth-fault current of the high-voltage side of brake coil 109 can be blocked by turning off switch 117.However, due to needing more More switch elements and corresponding control, can cause Figure 1B circuit to become more complicated and expensive.

Improved as another kind, inverse-excitation type switch power-supply can be realized using transformer., can be with due to the presence of transformer Isolation power supply is realized for brake coil.Due to this isolation, even if there is earth fault, circuit in one end of brake coil Also can work on.However, this scheme needs extra big and expensive transformer, and need to be used for DC support electric capacity The charging circuit of device.Therefore, extra cost is added.

It can be seen that the such scheme of prior art there is it is such or such the problem of, such as tentaculum noise in operation During larger, failure cut-off velocity slowly so as to cause fuse to be burned out, circuit cost is higher etc..In view of this, it is desirable to be able to extremely Partially avoid the D/C power of disadvantages mentioned above.

Utility model content

According to the one side of the disclosure, there is provided a kind of direct current (DC) power supply, such as can be used for the brake to elevator Coil power supply.The D/C power includes the first rectifier and the second rectifier.First exchange (AC) terminal of first rectifier can be with The first terminal of power supply AC networks is couple to, and the second AC terminal is couple to the first AC terminal of the second rectifier.Second rectification Second AC terminal of device can be couple to the Second terminal of power supply AC networks.First DC terminals of the second rectifier and the 2nd DC ends Son can provide DC power supplies to load.In addition, the D/C power also includes the first DC terminals and second for being coupled in the first rectifier Controllable power semiconductor switch between DC terminals.

In specification and claims, " coupling " and " connection " both includes direct coupling/connection, also including indirect coupling Connect/connect, i.e. be also possible to be connected with other additional components not describeds between the part for being mutually coupled/connecting, as long as not disobeying Spirit and scope of the present disclosure are carried on the back, then all these modifications are both fallen within the scope of the utility model.

As a result of semiconductor switch, it is possible to the shortcomings that avoiding mechanical switch (trigger).For example, it can reduce Noise, and can more promptly turn off so as to reduce the risk that fuse is burned out.

In certain embodiments, the first rectifier and the second rectifier can be full-wave rectifiers, for example, diode shape Into bridge rectifier.For example, each rectifier can include first to fourth diode coupled as follows：One or two pole Pipe forward direction is coupled between the first AC terminal of corresponding rectifier and the first DC terminals, and the second diode forward is coupled in corresponding whole Between the second AC terminal and the first DC terminals that flow device, the 3rd diode forward be coupled in the 2nd DC terminals of corresponding rectifier with Between first AC terminal, and the 4th diode forward be coupled in corresponding rectifier the 2nd DC terminals and the second AC terminal it Between.

In certain embodiments, controllable power semiconductor switch can be controlled as according to certain Trigger Angle and connect and Shut-off, to obtain desired voltage between the first DC terminals of the second rectifier and the 2nd DC terminals.

By controlling the Trigger Angle of controllable power semiconductor switch, the DC output voltages of the D/C power can be controlled.

Further, dc source has the power supply state to power to the load and the off-position not powered to the load. By dc source from during off-position switches to power supply state, controllable power semiconductor switch can be controlled as according to The Trigger Angle of change turns on and off so that the voltage between the first DC terminals of the second rectifier and the 2nd DC terminals is with slope Shape rises, and/or by dc source, from during power supply state switches to off-position, controllable power semiconductor is opened Pass is controlled as turning on and off according to the Trigger Angle of change so that the first DC terminals of the second rectifier and the 2nd DC terminals it Between voltage declined with ramped shaped.For example, it can be connected after the voltage over zero of AC supply networks by the predetermined time Controllable power semiconductor switch, and can close to AC supply networks next time at voltage over zero turn off controlled power partly lead Body switchs.

This is particularly useful when applied to elevator brake coil, because by the power supply and power-off of this ramp type, can To reduce noise of the brake when opening and closing.

In one embodiment, load can be elevator brake coil.First DC terminals of the second rectifier and second DC terminals can be connected respectively to the first terminal and Second terminal of brake coil.

In the case of elevator brake coil, the D/C power can also include current sensor, for sensing brake Electric current at the first terminal and Second terminal of coil.Controllable power semiconductor switch can be controlled as appointing what is sensed One electric current indicates to turn off during earth fault.

Switched by controllable power semiconductor, the high-voltage side of brake coil and connecing for ground voltage side both sides can be blocked Earth fault electric current, without setting more switches.

This current sensor can be the independent current sensor for sensing the electric current at brake coil both ends simultaneously, or Person can be two current sensors for sensing the electric current at brake coil both ends respectively.

In addition, current sensor also senses the shake in electric current.This shake can indicate the degree of wear of braking brake rubber block.

In one embodiment, the D/C power can also include inductor, and the inductor switchs with controllable power semiconductor It is connected in series between the first DC terminal of the first rectifier and the second DC terminal.When this can be avoided occurring earth fault Electric current become it is too much so as to damage circuit devcie as switch and diode.

In one embodiment, controllable power semiconductor switch can include it is following any one：Metal oxide is partly led Body field-effect transistor (MOSFET), igbt (IGBT) and bipolar transistor (BIS).

Brief description of the drawings

Figure 1A is to show a kind of circuit diagram of the existing dc source for brake coil；

Figure 1B is the circuit diagram for showing another existing dc source for brake coil；

Fig. 2 is the circuit diagram for showing the dc source according to the embodiment of the present disclosure；

Fig. 3 is to show the schematic diagram shaken according to the electric current of the embodiment of the present disclosure；

Fig. 4 is the schematic diagram for showing the switch control time sequence according to the embodiment of the present disclosure；

Fig. 5 is to show the schematic diagram with change triggers angle controlling switch according to the embodiment of the present disclosure；

Fig. 6 is the circuit diagram for showing the dc source according to another embodiment of the disclosure.

Embodiment

The disclosure is described in detail with reference to the accompanying drawings and detailed description.It should be noted that the disclosure does not answer office It is limited to embodiment described below.In addition, for simplicity eliminate pair does not have the public affairs of direct correlation with the disclosure The detailed description of technology is known, to prevent understanding of this disclosure from causing to obscure.

Fig. 2 is the circuit diagram for showing direct current (DC) power supply according to the embodiment of the present disclosure.

As shown in Fig. 2 two-stage rectifier can be included according to the D/C power 200 of the embodiment：G1 and G2.Rectifier can be with The AC power rectifiers of (AC) input side are exchanged into DC electric power, and are exported in its DC outlet side.Correspondingly, each rectifier can be with With AC (input) terminals and DC (output) terminal.As described below, wherein one-level (G1) may be used as voltage adjustment level, and another Level (G2) may be used as rectification stage.

Each rectifier G1, G2 may each be full-wave rectifier, such as the bridge rectifier that diode is formed.Shown in Fig. 2 Example in, rectifier G1 includes first to fourth diode G1a-G1d.First diode G1a forward directions are coupled in rectifier G1 The first AC terminal G1_{AC_a}With rectifier G1 the first DC terminals G1_{DC_a}Between, the second diode G1b forward directions are coupled in rectifier G1 the second AC terminal G1_{AC_b}With rectifier G1 the first DC terminals G1_{DC_a}Between, the 3rd diode G1c forward directions are coupled in rectification Device G1 the 2nd DC terminals G1_{DC_b}With rectifier G1 the first AC terminal G1_{AC_a}Between, and the 4th diode G1d forward directions are coupled in Rectifier G1 the 2nd DC terminals G1_{DC_b}With rectifier G1 the second AC terminal G1_{AC_b}Between.Similarly, rectifier G2 can be wrapped Include first to fourth diode G2a-G2d.First diode G2a forward directions are coupled in rectifier G2 the first AC terminal G2_{AC_a}With Rectifier G2 the first DC terminals G2_{DC_a}Between, the second diode G2b forward directions are coupled in rectifier G2 the second AC terminal G2_{AC_b} With rectifier G2 the first DC terminals G2_{DC_a}Between, the 3rd diode G2c forward directions are coupled in rectifier G2 the 2nd DC terminals G2_{DC_b}With rectifier G2 the first AC terminal G2_{AC_a}Between, and the 4th diode G2d forward directions are coupled in rectifier G2 the 2nd DC Terminal G2_{DC_b}With rectifier G2 the second AC terminal G2_{AC_b}Between.

It is to be herein pointed out those skilled in the art will know that the other configurations of rectifier, configuration only conduct in this Example provides.

Rectifier G1 the second AC terminal G1_{AC_b}Rectifier G2 the first AC terminal G2 can be couple to_{AC_a}.In addition, rectification Device G1 the first AC terminal G1_{AC_a}And rectifier G2 the second AC terminal G2_{AC_b}AC supply networks can be couple to, specifically The first terminal 201a and 201b of AC supply networks are connected respectively to, for receiving AC power supplies.For example commercial electricity of AC supply networks Net.In the case where three-phase or more phase AC powers, the first terminal 201a and 201b can represent a phase therein.

In addition, rectifier G2 the first DC terminals G2_{DC_a}With the 2nd DC terminals G2_{DC_b}It can be used for providing DC confessions to load Electric (for example, D/C voltage or DC electric current).In this example, the example using elevator brake coil 209 as load.It is for example, whole Flow device G2 the first DC terminals G2_{DC_a}With the 2nd DC terminals G2_{DC_b}The first terminal of brake coil 209 can be connected respectively to (high-voltage side terminal) and Second terminal (low voltage side terminal).But disclosure not limited to this.D/C power described here 200, which go for other, needs the part of direct current supply.

In the case of elevator brake coil, in DC outlet sides, smoothing capacity device can be not provided with, because braking The big inductance of device coil causes DC current easily to maintain and (be not easy to be mutated).Thus, it is possible to reduce the cost of circuit.In addition, In the example, it is not necessary to be the extra reverse parallel connection fly-wheel diode of brake coil 209, the diode in rectifier G2 can rise Acted on to identical.

In addition, in order to suppress the factors such as the harmonic wave in AC input to meet Electro Magnetic Compatibility (EMC) requirement, can also be in AC Input sets EMC filter networks 203 (for example, filter network that the inductance L and electric capacity C shown in Fig. 2 are formed).

In the D/C power, the first rectifier G1 the first DC terminals G1_{DC_a}With the 2nd DC terminals G1_{DC_b}Between by can Control power semiconductor switch 211 is connected.Due to the first rectifier G1 rectified action, so controlled power can be used herein Semiconductor switch 211, because being consistent in the course of the work (in this example, from up in Fig. 2 by its sense of current Under direction).For example, controllable open semiconductor switch 211 can be any gate control (gate-controlled) switch, bag Include mos field effect transistor (MOSFET), igbt (IGBT), bipolar transistor (BIS) etc..By using semiconductor switch, compared to mechanical switch, noise during switch motion can be reduced.

In order to tackle failure such as earth fault or short trouble, current sensor (for example, Hall element etc.) can be passed through To sense the electric current at the both ends of brake coil 209.The sensing result of current sensor can be input to controller 215.Controller 215 can indicate failure (for example, brake coil 209 first according to the sensing result of current sensor, such as in sensing result Electric current at terminal is not equal to the electric current at Second terminal) when, the shut-off of control controllable power semiconductor switch 211.

By controlling the ON/OFF of (such as by controller 215) controllable power semiconductor switch 211, can control Confession power off to brake coil 209.As a result of semiconductor switch, this ON/OFF is relatively quick.Root According to the present embodiment, break time can accomplish to be less than 20 microseconds, even less than 10 microseconds, and therefore can reduce fuse and be burnt The risk ruined.

Because the electric current on coil is inductance current, zero will not be immediately become.When failures are detected, it is necessary to backup path Discharge the electric current.For example, in the embodiment of fig. 2, if controllable power semiconductor switch 211 disconnects, the electric current on coil It can discharge along the first to fourth diode G2a-G2d flowings in the second rectifier G2 and therefore.

In order to avoid the electric current in ground connection or short trouble is (for example, flow through controllable power semiconductor switch 211 and each two The electric current of pole pipe) it is excessive, can be with controlled power between the first rectifier G1 the first DC terminal and the second DC terminal Semiconductor switch 211 is connected in series an inductor 205.For example, inductor 205 can be connected to controllable power semiconductor switch 211 and rectifier G1 the first DC terminals G1_{DC_a}Between.

Referring to Fig. 3, transverse axis represents the time, and the longitudinal axis represents electric current.When braking brake rubber block works, in the electric current of brake coil Small shake occurs (at arrow meaning).In accordance with an embodiment of the present disclosure, this electricity can be monitored by current sensor Dither flow, and it is possible thereby to calculate the distance between braking brake rubber block and brake disc.This shake can indicate the mill of braking brake rubber block Damage degree.Controller 215 can signal replacing brake rubber block according to monitoring result.

To the control of controllable power semiconductor switch 211 during except breaking down, controllable power semiconductor can also be controlled Switch 211 turns on and off according to certain Trigger Angle, with the first DC terminals of the second rectifier and the 2nd DC terminals it Between obtain desired voltage.It is similarly to the control of bidirectional triode thyristor element in dimmer circuit.

Fig. 4 is the schematic diagram for showing the switch control time sequence according to the embodiment of the present disclosure, and wherein transverse axis represents the time, is indulged Axle represents voltage.

As shown in figure 4, in AC input side, AC supply voltages (shown in the gray line in Fig. 4, e.g. sinusoidal waveform) be present. In normal work, controllable power semiconductor switch 211 can be connected not always, but (relative according to certain Trigger Angle In certain timing phase in other words of AC supply voltages, more specifically, such as switch connection moment is relative to AC supply voltage mistakes Timing/phase relation of zero point) turn on and off.For example, can be after a zero crossing of AC supply voltages by predetermined Time connect controllable power semiconductor switch 211, and can be turned off at next zero crossing close to AC supply voltages can Power semiconductor switch 211 is controlled, as shown in the black line in Fig. 4.According to the difference of Trigger Angle, different D/C voltages can be exported. Depending on the above-mentioned scheduled time can be according to required DC output voltages.

It is different from dc source of the prior art in the D/C power, in the absence of any too high switching frequency.Example Such as, in the example of fig. 4, switching frequency be AC power supply frequency (for example, 50Hz or 60Hz) twice (for example, 100Hz or 120Hz).And the switching frequency in conventional chopper can be higher than 20kHz.

In one example, controllable power semiconductor switch 211 can turn on and off according to the Trigger Angle of change so that The D/C power be couple to power supply AC networks after DC output voltages risen with ramped shaped, and the D/C power from power supply AC networks DC output voltages are declined with ramped shaped before disconnection.

Fig. 5 is to show the schematic diagram with change triggers angle controlling switch according to the embodiment of the present disclosure.

Fig. 5 shows continuous some half periods (not differentiating between positive and negative) in time, and wherein transverse axis represents time, longitudinal axis table Show voltage.More specifically, Fig. 5 shows situation when being initially powered up.As shown in figure 5, it is being initially powered up namely from off-position When switching to power supply state, can one by one the half period change switch Trigger Angle.As shown in the dash area in figure, Trigger Angle can To be gradually reduced.Correspondingly, DC output voltages (area for being based at least partially on dash area) gradually increase, until reaching institute The DC output voltages needed.Thus it is possible to little by little it is powered to load.

In addition, when needing to power off namely switch to off-position from power supply state, Trigger Angle can gradually increase, and because This DC output voltage can be reduced gradually, until vanishing, that is, power off.Thus it is possible to little by little to load power down.

Although Fig. 5 shows that each half period changes the example of Trigger Angle, disclosure not limited to this.For example, triggering The change at angle can be slower, such as each two or more half period changes.

This is particularly advantageous in the case of brake coil.The opening moment of switch and the phase place change of closing moment cause Voltage is risen or fallen with ramp system so that the lower noise when turning off or on mechanical braking.

In the illustrated example shown in fig. 2, can be sensed respectively at the both ends of brake coil 209 by two current sensors Electric current I1, I2.But disclosure not limited to this.It can be sensed jointly by current sensor at the both ends of brake coil 209 Electric current I1, I2.

Fig. 6 is the circuit diagram for showing the D/C power according to another embodiment of the disclosure.

D/C power 200 ' shown in Fig. 6 is substantially the same with the D/C power shown in Fig. 2, in addition to current sense mode. As shown in fig. 6, a current sensor can be used only to measure the electric current at the both ends of brake coil 209.It is normal in order to ensure In the case of direction of the electric current in sensor it is identical, using the wire laying mode shown in Fig. 6 (at I1).So, sensed Electric current I1 be twice by the electric current of brake coil 209.

As set forth above, it is possible to by controller 215 come monitoring current and controlling switch.This controller 215 can be set In D/C power, or it can be arranged on outside D/C power.

Can be by circuit (for example, monolithic or more with the various features or functional module of equipment in the above-described embodiments Piece integrated circuit) realize or perform.The circuit for the function being designed to carry out described by this specification can include general place Reason device, digital signal processor (DSP), application specific integrated circuit (ASIC), field programmable gate array (FPGA) or other can compile Any combination of journey logical device, discrete door or transistor logic, discrete nextport hardware component NextPort or above-mentioned open-minded part.General procedure Device can be microprocessor or any existing processor, controller, microcontroller or state machine.Foregoing circuit can To be digital circuit or analog circuit.Occur the new of the existing integrated circuit of replacement because of the progress of semiconductor technology Integrated circuit technique in the case of, the application can also be realized using these new integrated circuit techniques.

As above, embodiment of the disclosure is described in detail by reference to accompanying drawing.But specific structure not office It is limited to above-described embodiment.The disclosure also includes changing without departing from any design of disclosure purport.Furthermore it is possible in claim In the range of the disclosure is variously changed, by obtained by the technological means that is combined as disclosed in different embodiments Embodiment is also contained in scope of the presently disclosed technology.The component with same effect described in above-described embodiment can phase Trans-substitution.

Although combined preferred embodiment of the present disclosure shows the application above, those skilled in the art will It will be appreciated that in the case where not departing from spirit and scope of the present disclosure, various modifications can be carried out to the disclosure, replaces and changes Become.Therefore, the disclosure should not be limited by above-described embodiment, and should be limited by appended claims and its equivalent.

Claims (12)

1. A kind of 1. dc source, it is characterised in that including：

   First rectifier, there is the first ac terminal and the second ac terminal and the first DC terminal and the second DC terminal, First ac terminal of wherein the first rectifier is used for the first terminal for being couple to Alternating Current Power Supply network；

   Second rectifier, there is the first ac terminal and the second ac terminal and the first DC terminal and the second DC terminal, First ac terminal of wherein the second rectifier is couple to the second ac terminal of the first rectifier, and the second of the second rectifier hands over Stream terminal is used for the Second terminal for being couple to Alternating Current Power Supply network, and the first DC terminal and the second DC terminal of the second rectifier Son is used to provide direct current supply to load；And

   Controllable power semiconductor switchs, and is coupled between the first DC terminal of the first rectifier and the second DC terminal.
2. 2. dc source according to claim 1, it is characterised in that the first rectifier and the second rectifier are that all-wave is whole Flow device.
3. 3. dc source according to claim 1 or 2, it is characterised in that the first rectifier and the second rectifier include First to fourth diode coupled as follows：

   First diode forward is coupled between the first ac terminal of corresponding rectifier and the first DC terminal,

   Second diode forward is coupled between the second ac terminal of corresponding rectifier and the first DC terminal,

   3rd diode forward is coupled between the second DC terminal of corresponding rectifier and the first ac terminal, and

   4th diode forward is coupled between the second DC terminal of corresponding rectifier and the second ac terminal.
4. 4. dc source according to claim 1 or 2, it is characterised in that controllable power semiconductor switch be controlled as by Turned on and off according to certain Trigger Angle, to be obtained between the first DC terminal and the second DC terminal of the second rectifier Desired voltage.
5. 5. dc source according to claim 1 or 2, it is characterised in that

   Dc source has to the power supply state of the load supplying and not to the off-position of the load supplying,

   By the dc source, from during off-position switches to power supply state, controllable power semiconductor switch is controlled To be turned on and off according to the Trigger Angle of change so that between the first DC terminal and the second DC terminal of the second rectifier Voltage is risen with ramped shaped, and/or

   By the dc source, from during power supply state switches to off-position, controllable power semiconductor switch is controlled To be turned on and off according to the Trigger Angle of change so that between the first DC terminal and the second DC terminal of the second rectifier Voltage is declined with ramped shaped.
6. 6. dc source according to claim 1 or 2, it is characterised in that Alternating Current Power Supply network voltage over zero it Afterwards controllable power semiconductor switch, and being closed next time at voltage over zero in Alternating Current Power Supply network are connected by the predetermined time Disconnected controllable power semiconductor switch.
7. 7. dc source according to claim 1 or 2, it is characterised in that load is elevator brake coil, wherein, second The first DC terminal and the second DC terminal of rectifier are used for the first terminal and for being connected respectively to elevator brake coil Two-terminal.
8. 8. dc source according to claim 7, it is characterised in that also include：

   Current sensor, the electric current at the first terminal and Second terminal for sensing elevator brake coil,

   Wherein, controllable power semiconductor switch is controlled as turning off when any electric current sensed indicates earth fault.
9. 9. dc source according to claim 8, it is characterised in that two current sensors be present, for feeling respectively The electric current surveyed at the first terminal and Second terminal of elevator brake coil.
10. 10. dc source according to claim 8, it is characterised in that current sensor is additionally operable to sense trembling in electric current It is dynamic.
11. 11. dc source according to claim 1 or 2, it is characterised in that also including inductor, the inductor with it is described Controllable power semiconductor switch is connected in series between the first DC terminal of the first rectifier and the second DC terminal.
12. 12. dc source according to claim 1 or 2, it is characterised in that controllable power semiconductor switch includes following Meaning is a kind of：Mos field effect transistor, igbt and bipolar transistor.