CN209488540U - Hot memory circuit, electronic trip unit, breaker - Google Patents
Hot memory circuit, electronic trip unit, breaker Download PDFInfo
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- CN209488540U CN209488540U CN201920369795.1U CN201920369795U CN209488540U CN 209488540 U CN209488540 U CN 209488540U CN 201920369795 U CN201920369795 U CN 201920369795U CN 209488540 U CN209488540 U CN 209488540U
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Abstract
The utility model discloses a kind of hot memory circuits, current sampling circuit, the capacitor charge and discharge circuit being connect including microprocessor and respectively with microprocessor, current sampling circuit is used to for the sampled signal of loop current being supplied to microprocessor, and the capacitor charge and discharge circuit is used for the storage capacitor for being included to itself under micro-processor control and carries out charge and discharge；Capacitor charge and discharge circuit is made of resistance R1, resistance R2, storage capacitor C1, diode D1, one end of resistance R1 and a port I/O of microprocessor connect, the other end is connect with the anode of diode D1, the cathode of diode D1 is connect with one end of the anode of storage capacitor C1, resistance R2, and the cathode of storage capacitor C1 and the other end of resistance R2 are grounded；The anode of diode D1 is also connect with a port AD of the microprocessor.The invention also discloses a kind of electronic trip units and a kind of breaker.
Description
Technical field
The utility model relates to a kind of hot memory circuits, belong to low voltage electrical apparatus technology field.
Background technique
Thermomagnetic type overcurrent protection electric appliance is heated since its bimetallic sheet structure has to be gradually curved the cooling spy being gradually recovered
Property, therefore ability of threading off again of closing a floodgate with preferable overcurrent, but electronic type overcurrent protection electric appliance has no bimetallic sheet structure, and it can only
It goes to simulate the similar cooling characteristic restored of bimetal leaf heated bending using certain ad hoc fashions by electronic protection unit, so that
It also has preferable overcurrent combined floodgate and threads off again ability.Then, " heat memory " function of electronic type overcurrent protector just meet the tendency of and
It is raw.Power off that hot memory function generallys use at present is to be charged to external storage capacitor by control to record current major loop
Energy accumulation, with the natural discharge process of capacitor come simulate under power blackout situation major loop release can, the voltage at capacitor both ends is anti-
The energy situation of major loop is reflected.
Electric current is calculated as by a kind of prior art as shown in Figure 1, when detecting overload current by current transformer 2
Corresponding energy exports one fixed width pulse control triode Q1 conducting, the electric current of such supply voltage VCC by microprocessor 4
Capacitor C1 is flowed to by R1, Q1, D1, while microprocessor 4 is made of detection operational amplifier, resistance R3, resistance R4
Voltage follower output voltage indirect gain capacitor C1 on voltage, and to present microprocessor 4 calculate corresponding energy
Accumulating value relatively after, adjust pulse width and control the charging voltage on capacitor C1, when the energy of overload accumulation reaches disconnected
When the device operation condition of road, microprocessor 4 controls tripping coil 3 and cuts off main circuit power, and supply voltage (VCC) is no longer to capacitor C1
It charges, and oneself voltage of charging starts slowly to discharge by resistance R5.When closing a floodgate again later microprocessor 4 by voltage with
The voltage remained in capacitor C1 is acquired with device 5, then this voltage is converted into the residual energy magnitude of equal proportion.
Power-off decision circuitry increased to the improved patent of the prior art such as CN202837860U, energy value stores when power-off
In nonvolatile storage；Patent CN202387999U increase PWM compare occur circuit advanced optimized control method.But
Prior art has been all made of amplifier and a variety of discrete components form hot memory circuit, more using component number, electricity
Line structure is relative complex, is unfavorable for the miniaturization of breaker.
Utility model content
The technical problem to be solved by the utility model is to overcome the shortage of prior art, a kind of hardware circuit letter is provided
Hot memory circuit and its hot accumulating method single, number of elements is few reduces electronics so as to effectively reduce electronic trip unit volume
Buckle releaser cost meets breaker small form factor requirements.
The hot memory circuit of the utility model, the current sample electricity being connect including microprocessor and respectively with microprocessor
Road, capacitor charge and discharge circuit, the current sampling circuit is used to the sampled signal of loop current being supplied to microprocessor, described
Capacitor charge and discharge circuit is used for the storage capacitor for being included to itself under micro-processor control and carries out charge and discharge；The capacitor fills
Discharge circuit is made of resistance R1, resistance R2, storage capacitor C1, diode D1, and one of one end of resistance R1 and microprocessor
The connection of the port I/O, the other end are connect with the anode of diode D1, the cathode of diode D1 and anode, the resistance of storage capacitor C1
One end of R2 connects, and the cathode of storage capacitor C1 and the other end of resistance R2 are grounded；Diode D1 anode also with it is described micro-
One port AD of processor connects.
The hot accumulating method of hot memory circuit as described above, when microprocessor detects circuit electricity by current sampling circuit
When stream, electric current is calculated as corresponding energy, and fill to storage capacitor C1 by the pulse that the port I/O exports one fixed width
Electricity, meanwhile, only during the pulse generates, microprocessor passes through the capacitance voltage on the AD Port detecting storage capacitor C1
And it is converted into energy, compared with energy accumulation value corresponding with currently calculated electric current, work as if the energy being converted into is less than
The energy of preceding calculating continues to output pulse then to control the charging voltage of storage capacitor C1, accomplishes energy accumulation and capacitance voltage
Matching stop exporting pulse if the energy being converted into is greater than the energy that currently calculates；After the power-off of hot memory circuit again
When powering on, microprocessor, which first issues a pulse, is connected diode D1, while passing through the AD Port detecting storage capacitor C1
On capacitance voltage and be converted into energy, and using this energy as the radix of current flow energy accumulation, repeat above-mentioned step
Suddenly；The capacitance voltage by AD Port detecting storage capacitor C1 specifically: pass through AD Port detecting diode D1 anode
Voltage V1, and the conduction voltage drop of diode D1 is subtracted to obtain the capacitance voltage V2 on storage capacitor C1 with voltage V1.
Following technical scheme can also be obtained according to identical utility model thinking:
A kind of electronic trip unit, including hot memory circuit as described above and the tripping electricity being connect with the microprocessor
Road.
A kind of breaker, including electronic trip unit as described above.
Compared with prior art, technical solutions of the utility model have the advantages that
The utility model detects capacitance voltage using the port AD of microprocessor, and microcontroller issues pulse and fills to capacitor
Electricity, while the port microcontroller AD can acquire capacitance voltage value, when powering on again after the power-off of hot memory circuit, need to only use I/O
Port, which issues a pulse signal, makes diode current flow to by AD port processing capacitance voltage value.Its used circuit elements
Number of packages amount is greatly decreased, and especially without integrated devices such as operational amplifiers, hardware circuit is realized simply, so as to effectively reduce
Electronic trip unit volume meets breaker small form factor requirements, and reduces electronic trip unit cost, improves the market competitiveness.
Detailed description of the invention
Fig. 1 is the circuit diagram of the prior art；
Fig. 2 is the structural block diagram of the utility model electronic trip unit；
Fig. 3 is the circuit diagram of the utility model electronic trip unit.
Specific embodiment
More, the circuit structure phase for component number of the use including amplifier present in existing hot memory circuit
To complicated deficiency, the thinking of the utility model is the electricity detected in capacitor charge and discharge circuit using the port AD of microprocessor
Hold voltage, so that circuit element quantity is greatly decreased, especially without integrated devices such as operational amplifiers, hardware circuit is real
It is now simple, and then electronic trip unit volume can be effectively reduced, meet breaker small form factor requirements, and reduce electronic trip unit at
This, improves the market competitiveness.
As shown in Figure 2 and Figure 3, the electronic trip unit of the utility model is set in breaker comprising microcontroller, electricity
Hold charge-discharge circuit, current sampling circuit, trip circuit；The charging circuit of capacitor charge and discharge circuit by resistance R1, diode D1,
Storage capacitor C1 is constituted, the port I/O (the present embodiment is PWM foot) connection of one end of resistance R1 and microcontroller, the other end with
The anode connection of diode D1, cathode are connect with storage capacitor C1 anode, storage capacitor C1 cathode ground connection；Discharge circuit is by resistance
R2, storage capacitor C1 are constituted, and resistance R2 is in parallel with storage capacitor C1；In addition to this, the anode of diode D1 is also and microcontroller
An AD foot connection.The breaker is arranged in external power supply and leads on the route of load, and breaker is connect with tripping coil,
Power protection is provided to load by tripping coil cut-off breaker.The line between breaker and load is arranged in current transformer
On the road, for detecting the electric current for being supplied to load.Microcontroller is connect with tripping coil and current transformer.
When microcontroller detects electric current by current transformer, electric current is calculated as corresponding energy, then by micro-control
The pulse (such as pulse width is set as 20ms) of the end the PWM output one fixed width of device processed, by resistance R1, diode D1 to storage
It can capacitor C1 charging.Due to the characteristic that there is diode forward conduction reversely to end, only during pulse generates, microcontroller
Device extrapolates the voltage on storage capacitor C1 by the voltage V1 of AD Port detecting diode D1 anode over the ground with this voltage
The value of V2, voltage V2 are the conduction voltage drop that voltage V1 subtracts diode D1 (it is the intrinsic parameter of the diode).Microcontroller
Voltage V2 is converted into energy, compared with the accumulated value of energy corresponding with what is currently calculated, is worked as if the energy of voltage V2 conversion is less than
The accumulated value of the energy of preceding calculating then continues to output the pulse that pulse width is 20ms；Work as if the energy of voltage V2 conversion is greater than
The accumulated value of the energy of preceding calculating then stops exporting pulse, and so on.Storage capacitor C1 is controlled by continuing to output pulse
On charging voltage, to accomplish the matching of energy accumulation and capacitance voltage.
The accumulation of current energy can be used following relational expression to indicate: En=En-1*P+Sn(1), EnFor the tired of n-th periodical energy
Product value, En-1For the accumulated value of (n-1)th periodical energy, P is attenuation coefficient, SnThe energy value calculated for n-th of periodic current.
In the utility model, voltage V2 is converted into energy with the following method by microcontroller:
According to RC discharge curve formulaWherein RC is discharge time constant, and V is current time voltage
(V2 i.e. in this patent), VEIt is also possible to preset charging voltage value in that patent for the fully charged voltage of capacitor, T is
Time variable.
Energy attenuation calculates E according to following formulan=En-1* P, wherein EnFor the energy in n-th of period, En-1It is (n-1)th
The energy in period, P are attenuation coefficient, therefore have following formula establishment:
E0Gross energy when for preset tripping, P are attenuation coefficient, and Δ t is damped cycle, and T is time variable, and E is to work as
Preceding energy.According to above formula, there is following transformational relation for any time T capacitance voltage and energy:
After energy accumulation reaches the operation condition of breaker setting, microcontroller control tripping coil keeps breaker dynamic
Make, disengagement failure route.After power-off, the charge on storage capacitor C1 is discharged by resistance R2, the decaying of analog energy.When
Breaker closes a floodgate again when powering on, and microcontroller, which first issues a pulse, is connected diode D1, to reduce pulse pair charging electricity
The influence of appearance, the burst length is as short as possible, preferentially may be configured as 32us, and microcontroller detects diode D1 anode over the ground again
Voltage V1, and the voltage V2 on storage capacitor C1 at this time is extrapolated with this voltage, is calculated with voltage V2 current after decaying
Dump energy, and using this as radix (the i.e. E of relational expression (1) of energy accumulation againn-1), it repeats the above process.To real
The heat memory of energy after now powering off.
It further, only need to be in current overload, in repetition when the calculating of energy accumulation is only associated with current overload
State process.The accumulation of current energy can be used following relational expression to indicate: En=En-1+Sn(2), EnFor the accumulation of n-th of periodical energy
Value, En-1For the accumulated value of (n-1)th periodical energy, SnThe energy value calculated for n-th of periodic current.When electric current nonoverload, Sn
As 0, microcontroller stops output pulse, and the accumulated value of current energy is decayed according to attenuation coefficient.Current energy tires out
Product can be used following relational expression to indicate: En=En-1* (3) P, EnFor the accumulated value of n-th of periodical energy, En-1For (n-1)th period energy
The accumulated value of amount, P are attenuation coefficient.It is powered on again after hot memory circuit power-off, microcontroller, which first issues a pulse, makes two poles
Pipe D1 conducting, microcontroller detects the voltage V1 of diode D1 anode over the ground again, and extrapolates storage capacitor at this time with this voltage
Voltage V2 on C1 calculates current dump energy after decaying with voltage V2, if current overload, using this energy as working as
Radix (the i.e. E of relational expression (2) of preceding current energy accumulationn-1), it repeats the above process；If electric current nonoverload, this energy is made
For radix (the i.e. E of relational expression (3) of current flow energy accumulationn-1).Or there are also a kind of processing mode, hot memory circuit is disconnected
It is powered on again after electricity, if electric current nonoverload, does not issue pulse, until detecting current overload, then the end PWM by microcontroller
The pulse of 20ms is exported, only during pulse generates, microcontroller passes through the voltage of AD Port detecting diode D1 anode over the ground
V1, and the voltage V2 on storage capacitor C1 is extrapolated with this voltage, voltage V2 is converted into energy by microcontroller, is calculated with current
The accumulated value of corresponding energy compare, so repeat.
In practical application, pressure drop when due to diode current flow is related with the forward current of diode, to obtain diode
The exact value of conduction voltage drop needs to be compensated accordingly when MCU is calculated.According to known theory, the voltage U and stream at PN junction both ends
Cross the relationship of the electric current I of PN junction are as follows:
Wherein UT=kT/q, k are Boltzmann constant, and T is thermodynamic temperature, and q is the electricity of electronics, and Is is reversed saturation
Electric current.When PN junction forward bias,Much larger than 1, therefore there are following approximation relations:
If the impulse level of PWM port output is VCC, the voltage of diode cathode over the ground is V1, and the resistance value of resistance R1 is
R then hasIt sets up, it can be in the hope of diode dropDue to lead resistance,
Semiconductor bulk resistor etc. influences, and the pressure drop of diode will be on the basis of above-mentioned calculated result multiplied by a penalty coefficient A, the benefit
Repaying coefficient can be obtained by the method for test.Therefore the voltage V2=V1-A*U of charge and discharge capacitance.
Claims (3)
1. a kind of hot memory circuit, current sampling circuit, the capacitor connecting including microprocessor and respectively with microprocessor fill
Discharge circuit, the current sampling circuit are used to the sampled signal of loop current being supplied to microprocessor, the capacitor charge and discharge
Circuit is used for the storage capacitor for being included to itself under micro-processor control and carries out charge and discharge；It is characterized in that, the electricity
Hold charge-discharge circuit to be made of resistance R1, resistance R2, storage capacitor C1, diode D1, one end of resistance R1 and microprocessor
The connection of one port I/O, the other end are connect with the anode of diode D1, the anode of the cathode of diode D1 and storage capacitor C1,
One end of resistance R2 connects, and the cathode of storage capacitor C1 and the other end of resistance R2 are grounded；Diode D1 anode also with institute
State a port the AD connection of microprocessor.
2. a kind of electronic trip unit, which is characterized in that including hot memory circuit as described in claim 1 and with the micro process
The trip circuit of device connection.
3. a kind of breaker, which is characterized in that including electronic trip unit as claimed in claim 2.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201920369795.1U CN209488540U (en) | 2019-03-22 | 2019-03-22 | Hot memory circuit, electronic trip unit, breaker |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201920369795.1U CN209488540U (en) | 2019-03-22 | 2019-03-22 | Hot memory circuit, electronic trip unit, breaker |
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| Publication Number | Publication Date |
|---|---|
| CN209488540U true CN209488540U (en) | 2019-10-11 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201920369795.1U Active CN209488540U (en) | 2019-03-22 | 2019-03-22 | Hot memory circuit, electronic trip unit, breaker |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109905108A (en) * | 2019-03-22 | 2019-06-18 | 常熟开关制造有限公司(原常熟开关厂） | Hot memory circuit and its hot accumulating method, electronic trip unit, breaker |
-
2019
- 2019-03-22 CN CN201920369795.1U patent/CN209488540U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109905108A (en) * | 2019-03-22 | 2019-06-18 | 常熟开关制造有限公司(原常熟开关厂） | Hot memory circuit and its hot accumulating method, electronic trip unit, breaker |
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