CN105403827B - The abnormal detector of power switch - Google Patents
The abnormal detector of power switch Download PDFInfo
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- CN105403827B CN105403827B CN201410462884.2A CN201410462884A CN105403827B CN 105403827 B CN105403827 B CN 105403827B CN 201410462884 A CN201410462884 A CN 201410462884A CN 105403827 B CN105403827 B CN 105403827B
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- power switch
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- divider node
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Abstract
The present invention discloses a kind of abnormal detector of power switch, is connected on a current path of a power switch, including:One bleeder circuit, there is a divider node;One pressure difference switch, it is connected between the divider node of the bleeder circuit and the current path of power switch;When the voltage on the current path is less than one first setting value, the pressure difference switch turns on, the voltage of the divider node is set to be less than one second setting value, when the voltage on the current path is more than or equal to first setting value, pressure difference switch ends, when the voltage of the divider node is more than or equal to the second setting value, an abnormality alarm can be produced according to this.Whether the present invention is mainly more than or equal to a setting value when a power switch turns on according to the magnitude of voltage on one current path, to judge whether impedance related to temperature on its current path abnormal, so as whether for power switch generation abnormality alarm foundation.
Description
Technical field
The present invention relates to a kind of abnormal detector of power switch, more particularly to one kind is according to power switch and temperature phase
Whether the conduction impedance of pass is abnormal, as the correlation technique for producing abnormality alarm foundation.
Background technology
Power switch refer to that larger current, leakage current can be born it is smaller, under certain condition with preferable saturation conduction and
The transistor of cut-off characteristics, one of application power switch the most universal is mos field effect transistor at present
(MOSFET).Because power switch possesses above-mentioned characteristic, therefore it is frequently used on power-supply device, such as switch power supply
Device, refer to Fig. 7, and a kind of existing switched power supplier includes a rectification circuit 81, a circuit of power factor correction 82
An and DC-DC converting circuit 83 etc.;Wherein:The circuit of power factor correction 82 is included on DC power supply circuit
Inductance L1, diode, a power switch S1 and a pfc controller, the DC-DC converting circuit 83 include a transformer T1,
An one PDM keyer U1 and power switch S2, the PDM keyer U1 control terminal are connected with power switch S2
Connect, primary sides of the power switch S2 then with transformer T1 is connected.
From the foregoing, existing switched power supplier fully uses power switch as switch element, to adjust electricity
The power factor and progress Power convert in source.Because traditional PDM keyer U1 is to take rigid cut to power switch S2
Change, its switch terminals voltage and current waveform causes power switch S2 on or off because overlapped and not equal to zero
When great variation occurs, in addition to it will cause electromagnetic interference, for power switch S2, due to switch frequently and change
Greatly, therefore extremely it is easily damaged.In order to improve the problem of rigid switching is derivative, the technology for having soft switching then is developed appearance,
The overlapping area of its voltage x current when the so-called mainly reduced power switch of soft switching switches transient state, or even make faying surface
Product is zero, and it is zero to reach switch cost, and particular technique includes zero current switching (ZCS) or zero voltage switching (ZVS).
Although conventional pulse-width modulation controller passes through soft switching for power switch S2 rigid switching institute variation
Technology achieves a solution.However, also in the circuit of power factor correction 82 of switched power supplier, based on circuit characteristic,
Rigid switching is still taken in control of its pfc controller for power switch S1, and power switch S1 is frequently moved under rigid switching
Make, in addition to loss is produced, also probably due to temperature anomaly is raised and failed.As can be seen here, to ensure the power switch in system
Steady operation, have in fact for its working characteristics and whether abnormal necessity being monitored.
The content of the invention
Therefore present invention is primarily aimed at a kind of abnormal detector of power switch is provided, it is utilized and power switch
The related impedance variation of temperature, as power switch whether abnormal basis for estimation, to monitor the work shape of power switch at any time
State, and then ensure the stability of the equipment using power switch.
The technical way taken to reach object defined above is that the abnormal detector for making aforementioned power switches connects
On a current path of a power switch, and including:
One bleeder circuit, there is a divider node;
One pressure difference switch, it is connected between the divider node of the bleeder circuit and the current path of power switch;
When the voltage on the current path is less than one first setting value, the pressure difference switch turns on, and makes the electricity of the divider node
Pressure is less than one second setting value, when the voltage on the current path is more than or equal to first setting value, pressure difference switch cut-off, this point
When the voltage of pressure node is more than or equal to the second setting value, an abnormality alarm can be produced according to this.
The present invention is mainly using the temperature and the proportional corresponding relation of its conduction impedance of power switch, by judging work(
Whether the voltage on the current path of rate switch is more than a setting value, further to analyze whether its impedance raises extremely, and then
As power switch whether the basis for estimation of temperature anomaly;Using above-mentioned technology can effective monitoring power switch work shape
State, maintain system stable.
Below in conjunction with the drawings and specific embodiments, the present invention will be described in detail, but not as a limitation of the invention.
Brief description of the drawings
Fig. 1 is the circuit diagram of a preferred embodiment of the present invention;
Fig. 2A, Fig. 2 B are the equivalent circuit diagram of a preferred embodiment of the present invention;
Fig. 3 is the temperature and conduction impedance relativeness curve map of the power switch;
Fig. 4 is the oscillogram that the present invention is sampled with a digitial controller to bleeder circuit;
Fig. 5 is the circuit diagram of another embodiment of the present invention;
Fig. 6 is the circuit diagram that the present invention is used in switched power supplier;
Fig. 7 is the circuit diagram of switched power supplier known to one.
Embodiment
The structural principle and operation principle of the present invention are described in detail below in conjunction with the accompanying drawings:
On the abnormal detector of power switch of the present invention, one preferred embodiment, Fig. 1 is refer to, the power switch
Abnormal detector be to be connected on a current path of a power switch S1, and including:
One bleeder circuit 10, there is a divider node X;
One pressure difference switch 20, it is connected between divider node X and power switch the S1 current path of the bleeder circuit 10.
In the present embodiment, described power switch S1 is a mos field effect transistor
(MOSFET), in particular, it is a kind of N-type mos field effect transistor (NMOS).It should be noted that:
Foregoing N-type mos field effect transistor is only for example, and is not used to limit power switch S1 element class
Type.
Power switch S1 has a drain electrode, a source electrode and a grid, and it is drained, aforementioned currents path is formed between source electrode,
And be connected by draining by the pressure difference switch 20 with the divider node X of bleeder circuit 10, its source ground, grid is then as control
End.
The bleeder circuit 10 includes an a first resistor R1 and second resistance R1, first resistor R1, second resistance R2 with
One end mutually concatenates and forms foregoing divider node X, and first resistor R1 another end is to connect a direct current power Vcc, and second
Resistance R2 another end then connects power switch S1 source electrode and ground connection;The bleeder circuit 10 is by dc source Vcc, the first electricity
Resistance R1 and second resistance R2 determines one second setting value V2 according to voltage division formulas, and it is certain value, that is, in pressure difference switch 20
During cut-off, the normal voltage value that can be measured on divider node X.
Foregoing bleeder circuit 10 is to concatenate formed divider node X with first resistor R1, second resistance R2 to pass through the pressure
Difference switch 20 is connected with power switch S1 drain electrode, and in the present embodiment, described pressure difference switch 20 is a diode, two pole
Pipe connects the divider node X of bleeder circuit 10 with anode, is connected with its negative electrode with power switch S1 drain electrode, that is, the partial pressure
The divider node X of circuit 10 is connected by drain electrode of the diode forward with power switch S1.
Under foregoing structure, when power switch S1 is turned on, the voltage Vds between its power switch S1 leakage, source electrode is (i.e. electric
Voltage on flow path) it is small, now pressure difference switch 20 forward turns on, therefore the voltage Vx meetings on the divider node X of bleeder circuit 10
It is pulled down, and is less than the second setting value V2, equivalent circuit now is the electricity on the bleeder circuit 10 divider node X such as Fig. 2A
Press Vx then such as following formula:
The forward conducting voltage of Vf=pressure difference switches 20
But when power switch S1 temperature rise, under fixed current, its conduction impedance Rds also can be improved and then
(performance diagram that refer to Fig. 3), when power switch S1 constant temperature raise, its conduction impedance Rds and then improve, then its
Voltage Vds (drain-source electrode current Ids × conduction impedance Rds) is increased, and is waited more than one first setting value V1, pressure difference switch 20
End (equivalent circuit such as Fig. 2 B), then by judging that its voltage Vx is equal to the second setting value V2 on the divider node X of bleeder circuit 10
When, you can an abnormality alarm is produced according to this;Now the voltage on the bleeder circuit 10 divider node X is:
Vx=V2=Vcc × R2/ (R1+R2)
And when foregoing pressure difference switch 20 is diode, first setting value V1 is the forward conducting voltage of diode, about
0.7 volt.
The divider node X of foregoing bleeder circuit 10 voltage Vx can be by a digitial controller in a manner of sampling (Sampling)
Obtain, the digitial controller controls power switch S1 conducting simultaneously.Fig. 4 is refer to, is that the digitial controller drives the power
Switch S1 and the oscillogram sampled to the divider node X of the bleeder circuit 10, the digitial controller provide a drive signal Vgs with
Driving power switch S1 makees periodically to turn on, power switch S1 each turn-on cycle to the divider node of bleeder circuit 10
It is sampled, it is different with one can be produced by digitial controller when the divider node X voltages Vx of sampling is equal to the second setting value V2
Normal alarm.
Fig. 5 is refer to, is the another embodiment of the present invention, its basic framework is roughly the same with previous embodiment, should
Pressure difference switch 20 ' is still a diode, difference be in:The diode is connected with the divider node X of negative electrode and bleeder circuit 10
Connect, and be connected with anode with power switch S1 drain electrode.
In the aforementioned embodiment, the permanent voltage Vx for being more than divider node X of alleged the second setting value V2, concrete numerical value can be by
User's sets itself.Namely when power switch S1 is turned on, if conduction impedance Rds is normal, leakage, source voltage Vds be not big
In the forward conducting voltage of diode, the divider node X of bleeder circuit 10 voltage Vx is not up to the second setting value V2, sampling
Controller will not produce abnormality alarm;Wait power switch S1 temperature anomaly rise, its conduction impedance Rds is relative to be improved, leakage, source
Pole tension Vds is more than the forward conducting voltage of diode, causes the divider node X of bleeder circuit 10 voltage Vx to improve, when its is big
When the second setting value V2, the controller of sampling produces abnormality alarm immediately.
Fig. 6 is refer to, when aforementioned power switches S1 is used in circuit of power factor correction 82, aforementioned digital controller can
For the pfc controller in circuit of power factor correction 82, the abnormal detector 1 of the invention leakage with power switch S1 respectively
Pole, source electrode connect with pfc controller, and the pfc controller simultaneously further connects an alarm modules (Alarm), to detect
Divider node X voltage Vx produces abnormality alarm when being more than or equal to the second setting value V2.When power switch S1 is used in direct current pair
During DC converting circuit, aforementioned digital controller can be the PDM keyer in DC-DC converting circuit.
From the foregoing, the present invention mainly utilizes the temperature of the power switch corresponding pass proportional with its conduction impedance
Whether system, the voltage on current path by judging power switch are more than a setting value, its conduction impedance for further analysis
Whether abnormal rise, and then as whether the basis for estimation of power switch temperature anomaly alarm is produced, can thereby monitor work(at any time
The working characteristics of rate switch, and alarm is produced in time unusual condition occurs, to ensure that system is stable, and avoid causing to damage.
Certainly, the present invention can also have other various embodiments, ripe in the case of without departing substantially from spirit of the invention and its essence
Know those skilled in the art when can be made according to the present invention it is various it is corresponding change and deformation, but these corresponding change and become
Shape should all belong to the protection domain of appended claims of the invention.
Claims (9)
1. a kind of abnormal detector of power switch, it is connected on a current path of a power switch, it is characterised in that
Including:
One bleeder circuit, there is a divider node;
One pressure difference switch, it is connected between the divider node of the bleeder circuit and the current path of power switch, the pressure difference switch is
It is made up of a diode;
When the voltage on the current path is less than one first setting value, the pressure difference switch turns on, and makes the voltage of the divider node small
In one second setting value, when the voltage on the current path is more than or equal to first setting value, pressure difference switch cut-off, the partial pressure section
When the voltage of point is more than or equal to the second setting value, an abnormality alarm can be produced according to this.
2. the abnormal detector of power switch according to claim 1, it is characterised in that the anode connection of the pressure difference switch
The divider node of the bleeder circuit, its negative electrode connect the current path of the power switch.
3. the abnormal detector of power switch according to claim 2, it is characterised in that the bleeder circuit includes one first
Resistance and a second resistance, the first resistor, second resistance are so that one end mutually concatenates and is formed foregoing divider node, and this first
The another end of resistance connects a dc source, and the another end of second resistance connects source electrode and the ground connection of the power switch.
4. the abnormal detector of power switch according to claim 3, it is characterised in that the bleeder circuit is by the direct current
Power supply, first resistor and second resistance determine second setting value according to voltage division formulas.
5. the abnormal detector of power switch according to claim 4, it is characterised in that first setting value is the pressure difference
The forward conducting voltage of switch.
6. the abnormal detector of power switch according to claim 1, it is characterised in that the power switch is a metal oxygen
Compound semiconductor field effect transistor, it forms the current path by drain electrode, source electrode.
7. the abnormal detector of power switch according to any one in claim 1 to 6, it is characterised in that the partial pressure
The divider node of circuit connects a digitial controller.
8. the abnormal detector of power switch according to claim 7, it is characterised in that the digitial controller produces one and driven
Dynamic signal is entered with driving the power switch in each turn-on cycle of the power switch to the divider node of the bleeder circuit
Row sampling.
9. the abnormal detector of power switch according to claim 7, it is characterised in that the digitial controller is a PFC
Controller.
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CN201410462884.2A CN105403827B (en) | 2014-09-12 | 2014-09-12 | The abnormal detector of power switch |
Applications Claiming Priority (1)
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CN201410462884.2A CN105403827B (en) | 2014-09-12 | 2014-09-12 | The abnormal detector of power switch |
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CN105403827A CN105403827A (en) | 2016-03-16 |
CN105403827B true CN105403827B (en) | 2018-03-09 |
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CN201410462884.2A Active CN105403827B (en) | 2014-09-12 | 2014-09-12 | The abnormal detector of power switch |
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Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
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US10782334B2 (en) * | 2017-08-16 | 2020-09-22 | Infineon Technologies Ag | Testing MOS power switches |
CN110579713A (en) * | 2018-05-21 | 2019-12-17 | 郑州深澜动力科技有限公司 | Electric vehicle and state monitoring device of power battery and contactor thereof |
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DE2407601B1 (en) * | 1974-02-16 | 1975-07-24 | Bosch Gmbh Robert | Control device for reducing the speed of an alternating current? E? Ei of a series motor in no-load operation |
CN1089043A (en) * | 1992-09-21 | 1994-07-06 | 株式会社东芝 | Power transistor overcurrent protection circuit |
CN1349296A (en) * | 2000-10-12 | 2002-05-15 | 船井电机株式会社 | Circuit for producing high voltage used for toner powder system printer |
CN1388635A (en) * | 2001-05-29 | 2003-01-01 | 株式会社村田制作所 | Switch power source apparatus |
CN201409097Y (en) * | 2009-05-20 | 2010-02-17 | 青岛海信电器股份有限公司 | Feedback circuit of inverter controller and television utilizing same |
CN201413987Y (en) * | 2009-05-31 | 2010-02-24 | 青岛海信电器股份有限公司 | Protection circuit for inverter controller |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP3508696B2 (en) * | 2000-05-23 | 2004-03-22 | 三菱電機株式会社 | DC power supply |
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2014
- 2014-09-12 CN CN201410462884.2A patent/CN105403827B/en active Active
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE2407601B1 (en) * | 1974-02-16 | 1975-07-24 | Bosch Gmbh Robert | Control device for reducing the speed of an alternating current? E? Ei of a series motor in no-load operation |
CN1089043A (en) * | 1992-09-21 | 1994-07-06 | 株式会社东芝 | Power transistor overcurrent protection circuit |
CN1349296A (en) * | 2000-10-12 | 2002-05-15 | 船井电机株式会社 | Circuit for producing high voltage used for toner powder system printer |
CN1388635A (en) * | 2001-05-29 | 2003-01-01 | 株式会社村田制作所 | Switch power source apparatus |
CN201409097Y (en) * | 2009-05-20 | 2010-02-17 | 青岛海信电器股份有限公司 | Feedback circuit of inverter controller and television utilizing same |
CN201413987Y (en) * | 2009-05-31 | 2010-02-24 | 青岛海信电器股份有限公司 | Protection circuit for inverter controller |
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