CN109116122A - The method that non-isolated output inverter realizes insulation against ground resistance detection - Google Patents
The method that non-isolated output inverter realizes insulation against ground resistance detection Download PDFInfo
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- CN109116122A CN109116122A CN201810686583.6A CN201810686583A CN109116122A CN 109116122 A CN109116122 A CN 109116122A CN 201810686583 A CN201810686583 A CN 201810686583A CN 109116122 A CN109116122 A CN 109116122A
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- Prior art keywords
- output
- resistance
- insulation
- against ground
- detection
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
- G01R27/02—Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
- G01R27/16—Measuring impedance of element or network through which a current is passing from another source, e.g. cable, power line
- G01R27/18—Measuring resistance to earth, i.e. line to ground
Abstract
The invention discloses a kind of methods that non-isolated output inverter realizes insulation against ground resistance detection, an output capacitor is all connected in each inverting output terminal of non-isolated output inverter, all output capacitors, which are connected, to be set in output loop, output loop is also connected with an equivalent system insulation against ground resistance and insulation resistance detection signal generating circuit, and insulation resistance detects signal generating circuit and connects microprocessor；Tie point is the DC potential of output loop between output loop and insulation resistance detection signal generating circuit, the value of the DC potential of output loop is obtained using microprocessor progress signal acquisition and operation, the value is included in the operational formula of insulation resistance, accurate result is obtained；By changing the value of load, the range ability of different insulation resistances is obtained.The present invention can accurately measure the insulation against ground resistance value of output loop, can play effective safety protection function for non-isolated output inverter.
Description
Technical field
The present invention relates to a kind of methods that non-isolated output inverter realizes insulation against ground resistance detection, belong to detection skill
Art field.
Background technique
Traditional mechanical leakage switch is a kind of insulation resistance detection method of broad sense, can be used for non-isolated power supply
Earth leakage protective can tell tens milliamperes of common mode leakage current, industry mark from tens of amperes of differential mode main circuit current
Leakage current adjusting is mostly 30mA in standard, is on close level corresponding to insulation resistance in 10K or so (10000 Europe), and if in this way
The function of current in human body, will will cause certain injury, but the limitation of examined method, in order not to allow leakage switch
It malfunctions repeatedly, leakage current setting valve cannot be too small, that is, can not detect higher insulating resistance value, may be only available for small
Power grade.
And for hundreds of high-power electric currents to kilo-ampere, conventional earth leakage detection method can not be from the big function of upper kiloampere
The leakage current of tens of milliamperes is accurately differentiated in rate electric current.Due to can not be from so big running current reliable and stablely
So small insulation resistance leakage current is told, this method can not be applied.
For isolation output or over the ground for the power supply of high impedance (IT system), as the insulation resistance of Schneider detects
Instrument will realize that the detection of insulation against ground resistance is not so difficult, and online, reliable and stable insulation resistance detection may be implemented.So
And the product and the technology may not apply in non-isolated earthed system and power supply device.
In utility network, all three-phases and single-phase electrical source of power are earth neutral system, therefore, all non-isolated
The output loop of power supply is inherently present the ground resistance of low resistance, therefore can not be directly realized by insulation against ground resistance detection,
And the output of induction heating power, often with upper kilovolt high voltage, for the system of not electrical shock protection, there are safety
Hidden danger.
Summary of the invention
How the electric leakage of the non-isolated power supply of high-power electric current is carried out the technical problem to be solved by the present invention is solving
The problem of accurate detection.
In order to solve the above-mentioned technical problem, the technical solution of the present invention is to provide a kind of non-isolated output inverter is real
The method of existing insulation against ground resistance detection, which comprises the following steps:
Step 1: it is all connected with an output capacitor in each inverting output terminal of non-isolated output inverter, it is all
Output capacitor, which is connected, to be set in output loop, and output loop is also connected with an equivalent system insulation against ground resistance and insulation
Resistance detection signal generating circuit, insulation resistance detect signal generating circuit and connect microprocessor；Output loop includes and inversion
One end of all output capacitors of output end connection, the other end of output capacitor and load connect；
Step 2: tie point is the direct current of output loop between output loop and insulation resistance detection signal generating circuit
Position is obtained the value of the DC potential of output loop using microprocessor progress signal acquisition and operation, which is included in insulated electro
In the operational formula of resistance, accurate result is obtained；
The operational formula of insulation resistance are as follows:
When power supply Pow voltage be Up,
The loop current of insulation resistance detection:
And microprocessor signals collection voltages: Ui=R3 × i；
Operation obtains insulating resistance value Rx to be measured:
Step 3: the value by changing load obtains the range ability of different insulation resistances.
Preferably, the described insulation resistance detection signal generating circuit include high-voltage isolating resistance exchanged with high voltage every
From inductance, one end of high voltage exchange isolation inductance connects output loop, the other end and height electricity of high voltage exchange isolation inductance
One end of isolation resistance is pressed to be connected in series, the cathode of the other end connection power supply of high-voltage isolating resistance, the anode connection of power supply
One end of detection resistance, the other end of detection resistance and one end of filter capacitor connect, and the other end of filter capacitor connects power supply
Cathode, separate a grounding between detection resistance and filter capacitor, the anode connection input circuit of power supply.
Preferably, the power supply is the power supply that insulation resistance detects signal generating circuit；Power supply is a low-frequency ac
Power supply or a DC power supply.
Preferably, the load is the practical equivalent circuit for receiving energy；In induction heating power, load is one
Inductance coil, inductance coil is interior to be equipped with resistance；In variable-frequency power sources, load is motor or heater.
Preferably, in induction heating power, the output capacitor is resonant capacitance；It is described in variable-frequency power sources
Output capacitor be capacitance.
Preferably, the equivalent system insulation against ground resistance is set to any position of output loop.
Preferably, the microprocessor is independent processor, or for insertion detection calculations and controls the non-of program
The microprocessor of isolation output inverter itself.
Preferably, the value of the DC potential of the output loop is value of the direct current plus the electricity of low frequency variations.
Preferably, the inversion output of the non-isolated output inverter has 2-3 electrode；When inversion output has 2
When electrode, it is two that output capacitor is connect with inverting output terminal, and a load is equipped between two output capacitors；Work as inversion
When output has 3 electrodes, it is three that output capacitor is connect with inverting output terminal, the other end connection one of each output capacitor
A load.
Microprocessor of the invention can be independent, can also pass through in the microprocessor for being integrated in power supply itself
Insertion detection, operation and control program can be realized, and achieve the purpose that reduce cost, improve reliability.
The present invention connects the inverting output terminal of non-isolated output inverter using output capacitance, then in one end of load
Insulation resistance is installed and detects signal generating loop, and introduces microprocessor algorithm, acquire the signal and direct current is exported according to power supply
The variation of current potential compensates operation, carries out comprehensive operation according to the operating status of power supply, can accurately obtain insulation against ground electricity
Resistance value has higher accuracy and the scope of application compared to traditional mechanical electrical leakage detecting method.The present invention has real-time
On-line checking high resolution, does not increase system cost, can be applied to super high power, the electronic circuit adaptation that software and hardware combines
The advantages that range is wide；It can be applied to the power supply product of direct resonant mode induction heating power and all exchange outputs.Pass through this
Invention is realized and is protected personal safety, equipment safety.The present invention is suitable for install the power supply of output capacitance.
The present invention can accurately measure the insulation against ground resistance value of output loop under various environment, various operating conditions,
Effective safety protection function can be played for non-isolated output inverter.
Detailed description of the invention
Fig. 1 is insulating resistor detecting circuit figure (dual output capacitor and insulation resistance detect signal generating loop)；
Fig. 2 is insulating resistor detecting circuit figure (three output capacitances and insulation resistance detect signal generating loop).
Specific embodiment
In order to make the present invention more obvious and understandable, hereby with preferred embodiment, and attached drawing is cooperated to be described in detail below.
Embodiment 1
The present invention is a kind of method that non-isolated output inverter realizes insulation against ground resistance detection, passes through circuit knot
Micro process signal acquisition and software operation are closed, insulating resistance value is obtained and implements subsequent control logic, it is inverse to obtain non-isolated output
The result whether variable power source leaks electricity.
As shown in Figure 1, the circuit diagram of foregoing circuit is as follows:
It is first separately connected using one end of two output capacitors (i.e. first capacitor C1 and the second capacitor C2) non-isolated defeated
Two inverting output terminals of inverter out, the other end and output loop of two output capacitors are connected in series；Two outputs
Be in series between capacitor load (load such as coil, resistance, motor are connected to the other end of output capacitance), load with wherein
Insulation resistance detection signal generating circuit is connected between one output capacitor.Equivalent system insulation against ground resistance is connected to
In output loop, due to the practical very little of the resistance value of resistance R1, the position of equivalent system insulation against ground resistance, which can be, to be exported
Any position in circuit, does not influence calculated result.
Insulation resistance detection signal generating circuit includes that high-voltage isolating resistance R2 exchanges isolation inductance L2 with high voltage, high
One end of voltage exchange isolation inductance L2 connects output loop, the other end and high-voltage isolating of high voltage exchange isolation inductance L2
One end of resistance R2 is connected in series, the cathode of the other end connection power supply Pow of high-voltage isolating resistance R2, the anode of power supply Pow
The other end of one end of connecting detection resistance R3, detection resistance R3 is connect with one end of filter capacitor C3, and filter capacitor C3's is another
One end connects the cathode of power supply Pow, and a grounding is separated between detection resistance R3 and filter capacitor C3, and (i.e. detection circuit is grounded
Point), the anode connection input circuit of power supply Pow, input circuit connects microprocessor.Input circuit includes current-limiting resistance R4, limit
One end of leakage resistance R4 is connect with the anode of power supply Pow, and the other end of current-limiting resistance R4 is separately connected the first detection diode D1
Anode, second detection diode D2 cathode and microprocessor, two detection diode D2 both ends be connected in parallel to filtering
Capacitor C4.
Wherein, the inversion output of non-isolated output inverter has 2-3 electrode；In the present embodiment, inversion output has 2
Electrode, it is two that output capacitor is connect with inverting output terminal, and a load is equipped between two output capacitors；Non-isolated
There is 4 electronic power inverter parts (i.e. inverter T1- inverter T4) inside output inverter.
In induction heating power, output capacitor is resonant capacitance；In variable-frequency power sources, output capacitor is blocking electricity
Hold.If power supply tool, there are three above output end, the quantity of output capacitance is corresponding to be increased.
Loading (inductance L1 and resistance R1) indicates the practical equivalent circuit for receiving energy, load may there are many form,
In induction heating power, load is an inductance coil, and resistance R1 is lain within inductance coil, in variable-frequency power sources
In, load is the load such as motor, heater；
In signal generating circuit, high-voltage isolating resistance R2 is passed through by power supply Pow (low-frequency ac power or DC power supply)
Isolation inductance L2 is exchanged with high voltage and injects a signal voltage to output loop, and high-voltage isolating resistance R2 is exchanged with high voltage
Inductance L2 is isolated and plays high voltage decompression buffer action, filter capacitor C3 is played a filtering role, and inspection can be generated on detection resistance R3
Survey signal.
Input circuit is made of current-limiting resistance R4, the first detection diode D1, the second detection diode D2, filter capacitor C4
Current limliting, clamper and filter action, insulation against ground resistance of the signal through microprocessor acquisition, the available system of operation.
Power supply Pow is a low-frequency ac power or a DC power supply, is insulation resistance detection signal generating circuit
Power supply.
High-voltage isolating resistance R2 is the higher power resistor of resistance value ratio, it can make the voltage of signal generating circuit
It is reduced to low voltage level.High voltage exchange isolation inductance L2 is that an inductance is larger, the lesser reactor of electric current, it can be every
High voltage Alternating Component from power supply output loop.Filter capacitor C3 makes one stabilization of voltage into detection circuit, without dry
The signal voltage disturbed.
Current-limiting resistance R4, the first detection diode D1, the second detection diode D2, the limit that filter capacitor C4 is signal input
Stream, clamper and filter element, signal generator signal is via current-limiting resistance R4, the first detection diode D1, the second two poles of detection
Enter microprocessor circuit after pipe D2, filter capacitor C4 and is AD converted acquisition.
The present invention carries out signal acquisition using microprocessor and operation, microprocessor can be independent processor, can also
With insertion detection calculations and control program in the microprocessor of non-isolated output inverter itself.
Non-isolated output inverter is in the dynamic running process such as start and stop, the fluctuation of load, the DC potential of output loop
Ubas can change, and it, if not considering this variation, is feasible in static state that this, which is the key that can the present invention be achieved,
(no output, not real-time online), but once non-isolated output inverter is in operating status, the result of operation is by big amplitude wave
It is dynamic, it is unable to operate normally.The present invention by acquisition and operation simultaneously obtains the value of DC potential Ubas of output loop, and (this is one
The electricity of a direct current+low frequency variations, can be positive and also be negative), then the value of the DC potential Ubas of output loop is included in insulation
In the operational formula of resistance, accurate result can be just obtained.
Power supply Pow can be low-frequency ac signal voltage, be also possible to DC voltage, voltage Up, and expression operation is public
Formula is as follows:
The loop current of insulation resistance detection:
And microprocessor signals collection voltages: Ui=R3 × i；
It is possible thereby to which operation obtains insulating resistance value Rx to be measured:
In practice, thus it is possible to vary the value of high-voltage isolating resistance R2 and detection resistance R3 obtain different insulation
Resistance range ability improves the value of high-voltage isolating resistance R2 and detection resistance R3 in the very high occasion of basic insulation resistance, can
With measurement, calculating and the process range for obtaining tens megaohms of range and from tens kilo-ohms to tens megaohm；It insulate on basis
The lower occasion of resistance (such as water-cooling system), then should reduce the value of high-voltage isolating resistance R2 and detection resistance R3, can obtain
To several hundred kilo-ohms of ranges and from several hundred Europe to several hundred kilo-ohms of measurement, calculating and process range.
The present invention is a kind of insulation against ground resistor detection method, can be applied to non-isolated large power inverter power source (packet
Include induction heating power), its output loading circuit realize insulation against ground resistance detection, and can output operational process in into
Row on-line checking implements protection when detecting that insulation resistance is reduced to setting lowest threshold, disconnects power supply major loop, thus
Play personal safety and the protection of equipment safety.
The present invention obtains practical successful application, the power bracket covering of power supply in induction heating power product
80kW-1600kW, frequency range cover 100Hz-100000Hz, and three-phase 380VAC source current reaches 2720A.
The present invention is based on operation, display and controls that microprocessor realizes full digital, in addition to measurement and operation obtain absolutely
Edge resistance value further includes parameter setting, display insulation resistance actual value, executes alarm and protection etc..Digital calculation process tool
There are the remarkable advantages such as intuitive, accurate, competent complex calculation, adaptation range broadness.
The present invention can carry out subsequent alarm and protection, Ke Yitong after the resistance value for obtaining accurate insulation resistance
The breaker for crossing the tripping of disjunction major loop band, achievees the purpose that completely cut through energized circuit, play a protective role.
Present invention can apply to different products and different operating conditions to have benefited from micro- place under different operating conditions and environment
The function of managing calculation function and settable parameter, can set different range and process range, this significantly expands this hair
Bright application range.And under different operating conditions, the alarming value and protection value of insulation resistance are also that can be convenient setting, this makes
It is very flexible to obtain application of the invention.
Embodiment 2
In the present embodiment, inversion output has 3 electrodes, as shown in Fig. 2, connecting output capacitor with inverting output terminal is three
A, the other end of each output capacitor connects a load.Other are same as Example 1.
Claims (9)
1. a kind of method that non-isolated output inverter realizes insulation against ground resistance detection, which is characterized in that including following step
It is rapid:
Step 1: being all connected with an output capacitor, all output in each inverting output terminal of non-isolated output inverter
Capacitor, which is connected, to be set in output loop, and output loop is also connected with an equivalent system insulation against ground resistance and insulation resistance
Signal generating circuit is detected, insulation resistance detects signal generating circuit and connects microprocessor；Output loop includes exporting with inversion
One end of all output capacitors of connection is held, the other end of output capacitor and load connect；
Step 2: tie point is the DC potential of output loop between output loop and insulation resistance detection signal generating circuit
(Ubas), the value that the DC potential of output loop is obtained using microprocessor progress signal acquisition and operation, is included in the value absolutely
In the operational formula of edge resistance, accurate result is obtained；
The operational formula of insulation resistance are as follows:
When power supply Pow voltage be Up,
The loop current of insulation resistance detection:
And microprocessor signals collection voltages: Ui=R3 × i；
Operation obtains insulating resistance value Rx to be measured:
Step 3: the value by changing load obtains the range ability of different insulation resistances.
2. the method that a kind of non-isolated output inverter as described in claim 1 realizes insulation against ground resistance detection, special
Sign is that the insulation resistance detection signal generating circuit includes that high-voltage isolating resistance (R2) exchanges isolation electricity with high voltage
Feel (L2), one end of high voltage exchange isolation inductance (L2) connects output loop, and high voltage exchanges the another of isolation inductance (L2)
End and the one end of high-voltage isolating resistance (R2) are connected in series, and the other end of high-voltage isolating resistance (R2) connects power supply (Pow)
Cathode, one end of the positive connecting detection resistance (R3) of power supply (Pow), the other end and filter capacitor of detection resistance (R3)
(C3) one end connection, the cathode of other end connection power supply (Pow) of filter capacitor (C3), detection resistance (R3) and filter capacitor
(C3) grounding, the anode connection input circuit of power supply (Pow) are separated between.
3. the method that a kind of non-isolated output inverter as described in claim 1 realizes insulation against ground resistance detection, special
Sign is that the power supply (Pow) is the power supply that insulation resistance detects signal generating circuit；Power supply (Pow) is that a low frequency is handed over
Galvanic electricity source or a DC power supply.
4. the method that a kind of non-isolated output inverter as claimed in claim 3 realizes insulation against ground resistance detection, special
Sign is that the load is the practical equivalent circuit for receiving energy；In induction heating power, load is an inductor wire
Circle, inductance coil is interior to be equipped with resistance (R1)；In variable-frequency power sources, load is motor or heater.
5. the method that the non-isolated output inverter of one kind as described in claim 1 or 4 realizes insulation against ground resistance detection,
It is characterized in that, in induction heating power, the output capacitor is resonant capacitance；In variable-frequency power sources, the output
Capacitor is capacitance.
6. the method that a kind of non-isolated output inverter as described in claim 1 realizes insulation against ground resistance detection, special
Sign is that the equivalent system insulation against ground resistance is set to any position of output loop.
7. the method that a kind of non-isolated output inverter as described in claim 1 realizes insulation against ground resistance detection, special
Sign is that the microprocessor is independent processor, or the non-isolated output for insertion detection calculations and control program
The microprocessor of inverter itself.
8. the method that a kind of non-isolated output inverter as described in claim 1 realizes insulation against ground resistance detection, special
Sign is that the value of the DC potential of the output loop is value of the direct current plus the electricity of low frequency variations.
9. the method that a kind of non-isolated output inverter as described in claim 1 realizes insulation against ground resistance detection, special
Sign is that the inversion output of the non-isolated output inverter has 2-3 electrode；When inversion output has 2 electrodes, with
It is two that inverting output terminal, which connects output capacitor, and a load is equipped between two output capacitors；When inversion output has 3
When electrode, it is three that output capacitor is connect with inverting output terminal, and the other end of each output capacitor connects a load.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201810686583.6A CN109116122A (en) | 2018-06-27 | 2018-06-27 | The method that non-isolated output inverter realizes insulation against ground resistance detection |
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| CN201810686583.6A CN109116122A (en) | 2018-06-27 | 2018-06-27 | The method that non-isolated output inverter realizes insulation against ground resistance detection |
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| CN1948975A (en) * | 2006-11-14 | 2007-04-18 | 沈阳铝镁设计研究院 | Apparatus and method for testing absolute resistance to ground of electrolytic tank series |
| CN201364367Y (en) * | 2009-01-19 | 2009-12-16 | 株洲电力机车厂长河机电产品开发公司 | Alternating-current network insulating monitor |
| CN201886083U (en) * | 2010-12-13 | 2011-06-29 | 河北深海电器有限公司 | Measuring device for isolation resistance of vehicle DC (direct current) high-voltage system |
| CN102749562A (en) * | 2012-07-13 | 2012-10-24 | 安徽安凯汽车股份有限公司 | Insulation monitoring device and monitoring method of power cell of electric vehicle |
| JP2017142269A (en) * | 2013-11-22 | 2017-08-17 | 三菱電機株式会社 | Insulation detector and electric device |
| CN108051642A (en) * | 2017-11-28 | 2018-05-18 | 合肥合试检测股份有限公司 | High voltage dc bus insulation resistance detection device and detection method |
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2018
- 2018-06-27 CN CN201810686583.6A patent/CN109116122A/en not_active Withdrawn
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1948975A (en) * | 2006-11-14 | 2007-04-18 | 沈阳铝镁设计研究院 | Apparatus and method for testing absolute resistance to ground of electrolytic tank series |
| CN201364367Y (en) * | 2009-01-19 | 2009-12-16 | 株洲电力机车厂长河机电产品开发公司 | Alternating-current network insulating monitor |
| CN201886083U (en) * | 2010-12-13 | 2011-06-29 | 河北深海电器有限公司 | Measuring device for isolation resistance of vehicle DC (direct current) high-voltage system |
| CN102749562A (en) * | 2012-07-13 | 2012-10-24 | 安徽安凯汽车股份有限公司 | Insulation monitoring device and monitoring method of power cell of electric vehicle |
| JP2017142269A (en) * | 2013-11-22 | 2017-08-17 | 三菱電機株式会社 | Insulation detector and electric device |
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Application publication date: 20190101 |