CN110955290A - Intelligent temperature compensation device for high-precision high-power converter - Google Patents
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Abstract
The invention discloses an intelligent temperature compensation device for a high-precision high-power converter, which comprises: the device comprises a multiple temperature sampling unit, a precision and stability control unit, a curve loading unit and a digital PWM (pulse width modulation) adjusting unit which are electrically connected in sequence. The device can reduce the temperature coefficient index of the high-precision high-power converter to a level less than 20ppm when the converter works at the limit environment temperature, thereby greatly improving the precision of output voltage and current; the loop parameters can be automatically adjusted and controlled according to the corresponding relation between the measured temperature and the distribution parameters, so that the output stability in high and low temperature environments is greatly improved; the device has the function of automatically calibrating the temperature drift curve, realizes the active communication with a remotely connected program-controlled voltmeter, a program-controlled ammeter, a programmable electronic load and an environmental test chamber, and automatically executes calibration and curve drawing; all compensation methods and processes are automatic and intelligent, and unattended operation can be realized.
Description
Technical Field
The invention relates to the field of alternating current and direct current power supplies, electronic loads and high-power converter equipment, in particular to an intelligent temperature compensation device for a high-precision high-power converter.
Background
In the fields of industrial equipment, information communication, measurement control and the like, various high-precision alternating current and direct current stabilized power supplies and electronic loads are used in occasions of equipment development, maintenance guarantee, metering test and the like. In recent years, with the increasing level of industrial technology, various comprehensive requirements are put on power supplies, and environmental adaptability is one of the key indexes.
The high-precision AC/DC stable power supply has wide application; when tested at 23 +/-5 deg.c, the kilowatt-level high-performance serial products have output voltage programming and measuring precision up to 0.3% and output current programming and measuring precision up to 1%, and may be used in most application fields. Currently, the main problems with such power supplies are: 1) the working temperature range is wide in the requirement of environmental adaptability, and is mostly-40 to +60 ℃, even if the working temperature range is calculated according to the 100ppm temperature drift coefficient required by a high-performance power supply, when the power supply works in a high-temperature and low-temperature environment, the output voltage and current precision are reduced to 5 thousandths of a circle, and the difference is several times or more than ten times compared with the normal temperature. 2) Most key component parameters change along with the ambient temperature, so that the output index is degraded and even oscillation is caused, and the reliability is influenced. The application of the precision equipment in a complex environment is seriously influenced by the huge output difference of the high-precision power converter under the normal temperature environment and the high-low temperature environment; therefore, how to solve the above problems is a problem which needs to be solved urgently in the fields of alternating current and direct current power supplies, electronic loads, high-power converters and tests.
Disclosure of Invention
Based on the problems existing in the prior art, the invention aims to provide an intelligent temperature compensation device for a high-precision high-power converter, which can solve the problem that the reliability is influenced by the reduction of the precision of output voltage and current of an alternating current/direct current power supply, an electronic load, the high-power converter and the like due to the change of environmental temperature.
The purpose of the invention is realized by the following technical scheme:
the embodiment of the invention provides an intelligent temperature compensation device for a high-precision high-power converter, which comprises:
the device comprises a multiple temperature sampling unit, a precision and stability control unit, a curve loading unit and a digital PWM (pulse width modulation) adjusting unit; wherein the content of the first and second substances,
the multiple temperature sampling unit is provided with a plurality of groups of temperature sampling devices for connecting the high-precision high-power converter, can respectively acquire temperature signals of different circuit parts of the high-precision high-power converter, and respectively normalizes the acquired temperature signals of the different circuit parts of the high-precision high-power converter to form a rough temperature signal for output;
the precision and stability control unit is respectively electrically connected with the multiple temperature sampling unit and the curve loading unit, can perform signal distribution processing and distinguishing processing on each rough temperature signal corresponding to different circuit parts output by the multiple temperature sampling unit to respectively obtain temperature signals corresponding to current, an internal environment, voltage, a power switch device, a magnetic element and a second-order filter circuit, and forms a current temperature drift characteristic curve and a voltage temperature drift characteristic curve according to the temperature signals corresponding to the current and the voltage respectively and the temperature signals corresponding to the internal environment; forming a distribution parameter temperature drift characteristic curve according to the temperature signals corresponding to the power switch device, the magnetic element and the second-order filter circuit;
the curve loading unit is respectively electrically connected with the precision and stability control unit and the digital PWM adjusting unit, and can load the current temperature drift characteristic curve and the voltage temperature drift characteristic curve output by the precision and stability control unit and the distribution parameter temperature drift characteristic curve output by the precision and stability control unit to the digital PWM adjusting unit after calibrating the current temperature drift characteristic curve and the voltage temperature drift characteristic curve;
the digital PWM adjusting unit is respectively electrically connected with the curve loading unit and the high-precision high-power converter, can form PWM adjusting signals according to the current temperature drift characteristic curve, the voltage temperature drift characteristic curve and the distribution parameter temperature drift characteristic curve output by the curve loading unit, and controls the high-precision high-power converter through the PWM adjusting signals.
According to the technical scheme provided by the invention, the intelligent temperature compensation device for the high-precision high-power converter provided by the embodiment of the invention has the beneficial effects that:
by arranging the multiple temperature sampling units, the precision and stability control unit, the curve loading unit and the digital PWM adjusting unit which are connected in sequence, effective temperature measurement can be carried out on a plurality of important parts or components of the high-precision high-power converter, the compensation reference input voltage and the PWM signal of the power switch can be effectively adjusted and controlled by carrying out comprehensive data processing on a plurality of measuring points and combining the temperature drift and the distribution parameter curve which are automatically loaded and calibrated, and finally the temperature coefficient index which is less than 20ppm can be reached when the high-precision high-power converter works at the extreme environment temperature, so that the precision of the output voltage and the current can be greatly improved; the compensation device automatically adjusts and controls loop parameters according to the corresponding relation between the measured temperature and the distribution parameters, so that the output stability is greatly improved in a high-temperature and low-temperature environment; the compensation device can be automatically realized by a hardware circuit and a software control algorithm, does not need manual setting and adjustment, and can realize intelligent temperature compensation.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.
Fig. 1 is a schematic diagram illustrating a configuration of an intelligent temperature compensation device according to an embodiment of the present invention;
fig. 2 is a schematic diagram of a process in which a temperature sensor in a multiple temperature sampling unit is respectively connected with an output current precision sampling resistor and a power switch device in a nearby crimping manner according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of a flexible circuit application structure in a multiple temperature sampling unit according to an embodiment of the present invention;
FIG. 4 is a schematic diagram of an exemplary sampling circuit in the multiple temperature sampling units according to the embodiment of the present invention;
FIG. 5 is a schematic diagram of an input signal distribution circuit in the accuracy and stability control unit according to an embodiment of the present invention;
FIG. 6 is an oscilloscope interface diagram of input signal distribution waveforms in the accuracy and stability control unit according to an embodiment of the present invention;
FIG. 7 is a schematic diagram of a temperature drift curve of a precision sampling resistor σ R/R for output current according to an embodiment of the present invention;
the parts corresponding to each mark in the figure are: 1-multiple temperature sampling units; 11-precision current feedback module; 12-an internal ambient temperature feedback module; 13-output voltage feedback module; 14-power switch temperature module; 15-magnetic element temperature module; 16-second order filtering temperature module; 2-precision and stability control unit; 21-output current precision control module; 22-an internal ambient temperature control module; 23-output voltage precision control module; 24-a stability control module; 3-a curve loading unit; 31-temperature drift curve calibration module; 32-temperature drift curve loading module; 33-distribution parameter curve loading module; 4-a digital PWM adjusting unit; 5-high precision high power converter; a-a temperature sensor; b, burying a point at the bottom of the temperature sensor; c-a radiator; .
Detailed Description
The technical solutions in the embodiments of the present invention are clearly and completely described below with reference to the specific contents of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without making any creative effort, shall fall within the protection scope of the present invention. Details which are not described in detail in the embodiments of the invention belong to the prior art which is known to the person skilled in the art.
As shown in fig. 1, an embodiment of the present invention provides an intelligent temperature compensation apparatus for a high-precision high-power converter, which can perform measurement and control on the whole high-precision high-power converter to implement temperature compensation, and includes:
the device comprises a multiple temperature sampling unit, a precision and stability control unit, a curve loading unit and a digital PWM (pulse width modulation) adjusting unit; wherein the content of the first and second substances,
the multiple temperature sampling unit is provided with a plurality of groups of temperature sampling devices for connecting the high-precision high-power converter, can respectively acquire temperature signals of different circuit parts of the high-precision high-power converter, and respectively normalizes the acquired temperature signals of the different circuit parts of the high-precision high-power converter to form a rough temperature signal for output;
the precision and stability control unit is respectively electrically connected with the multiple temperature sampling unit and the curve loading unit, can perform signal distribution processing and distinguishing processing on each rough temperature signal corresponding to different circuit parts output by the multiple temperature sampling unit to respectively obtain temperature signals corresponding to current, an internal environment, voltage, a power switch device, a magnetic element and a second-order filter circuit, and forms a current temperature drift characteristic curve and a voltage temperature drift characteristic curve according to the temperature signals corresponding to the current and the voltage respectively and the temperature signals corresponding to the internal environment; forming a distribution parameter temperature drift characteristic curve according to the temperature signals corresponding to the power switch device, the magnetic element and the second-order filter circuit;
the curve loading unit is respectively electrically connected with the precision and stability control unit and the digital PWM adjusting unit, and can load the current temperature drift characteristic curve and the voltage temperature drift characteristic curve output by the precision and stability control unit and the distribution parameter temperature drift characteristic curve output by the precision and stability control unit to the digital PWM adjusting unit after calibrating the current temperature drift characteristic curve and the voltage temperature drift characteristic curve;
the digital PWM adjusting unit is respectively electrically connected with the curve loading unit and the high-precision high-power converter, can form PWM adjusting signals according to the current temperature drift characteristic curve, the voltage temperature drift characteristic curve and the distribution parameter temperature drift characteristic curve output by the curve loading unit, and controls the high-precision high-power converter through the PWM adjusting signals.
In the temperature compensation device, the multiple temperature sampling unit includes:
the device comprises a precision current feedback module, an internal environment temperature feedback module, an output voltage feedback module, a power switch temperature module, a magnetic element temperature module and a second-order filtering temperature module; wherein the content of the first and second substances,
the precise current feedback module, the internal environment temperature feedback module, the output voltage feedback module, the power switch temperature module, the magnetic element temperature module and the second-order filtering temperature module are respectively provided with a group of temperature sampling devices;
the temperature sampling devices of the precision current feedback module, the internal environment temperature feedback module, the output voltage feedback module, the power switch temperature module, the magnetic element temperature module and the second-order filtering temperature module are respectively connected to the output current precision sampling resistor, the loop control circuit, the output voltage feedback circuit, the power switch device, the magnetic element and the second-order filtering circuit of the high-precision high-power converter, and can respectively collect temperature signals of circuit parts of the output current precision sampling resistor, the loop control circuit, the output voltage feedback circuit, the power switch device, the magnetic element and the second-order filtering circuit.
In the temperature compensation device, the precision current feedback module, the internal environment temperature feedback module, the output voltage feedback module, the power switch temperature module, the magnetic element temperature module and the second-order filtering temperature module all adopt temperature sampling circuits.
In the temperature compensation device, the temperature sampling device of the precise current feedback module adopts a temperature sensor, and the temperature sensor is connected to the aluminum-based radiator connected with the output current precise sampling resistor in a manner that the radiator is in close compression joint or embedded in a point;
the temperature sampling device of the power switch temperature module adopts a temperature sensor which is connected to an aluminum-based radiator connected with the power switch device in a manner of nearby crimping of the radiator or embedding of the radiator;
the temperature sampling device of the internal environment temperature feedback module adopts two temperature sensors, wherein one temperature sensor is arranged on the surface of a printed circuit board of the loop control circuit, and the other temperature sensor is arranged in the space around the printed circuit board of the loop control circuit; the two temperature sensors respectively measure the surface temperature of the printed board of the measured part and the ambient temperature of the space around the circuit, and finally, the influence factor is converted through the weight of each circuit; in practical application, a plurality of temperature sensors (such as a plurality of circuit board surfaces and a plurality of positions in a case) can be respectively arranged according to different structures of the high-precision high-power converter, and the temperature of a plurality of environments (the single internal environment temperature is obtained through averaging, comparing or weighting) is measured at the same time to obtain the more accurate internal environment temperature.
The temperature sampling device of the output voltage feedback module adopts two temperature sensors, wherein one temperature sensor is arranged on the surface of a printed circuit board of the output voltage feedback circuit, and the other temperature sensor is arranged in the space around the printed circuit board of the output voltage feedback circuit; the two temperature sensors respectively measure the surface temperature of the printed board of the measured part and the ambient temperature of the space around the circuit, and finally, the influence factor is converted through the weight of each circuit;
the temperature sampling device of the power switch temperature module adopts a temperature sensor with a hollow structure at the bottom, the temperature sensor is arranged on a flexible circuit attaching structure, and the flexible circuit attaching structure is wound on the surface of a power switch device with the temperature to be measured;
the temperature sampling device of the magnetic element temperature module adopts a temperature sensor with a hollow structure at the bottom, the temperature sensor is arranged on a flexible circuit attaching structure, and the flexible circuit attaching structure is wound on the surface of a magnetic element with the temperature to be measured;
the temperature sampling device of the second-order filtering temperature module adopts a temperature sensor with a hollow-out structure at the bottom, the temperature sensor is arranged on a flexible circuit attaching structure, and the flexible circuit attaching structure is wound on the surface of a filtering electrolytic capacitor of a second-order filtering circuit of which the temperature is measured.
The flexible circuit pasting structure is matched with the temperature sensor with the hollow bottom, so that the surface temperature of a cylindrical device (such as an electrolytic capacitor) can be measured more accurately, and accurate parameters are provided for subsequent temperature compensation control.
In the temperature compensation device, the accuracy and stability control unit includes:
the device comprises an input signal distribution circuit, a temperature distinguishing and processing module, an output current precision control module, an internal environment temperature control module, an output voltage precision control module and a stability control module; wherein the content of the first and second substances,
the input signal distribution circuit is electrically connected with the multiple temperature sampling units, is respectively and electrically connected with the output current precision control module, the inner environment temperature control module, the output voltage precision control module and the stability control module through the temperature distinguishing and processing module, and can correspondingly distribute the rough temperature signals output by the multiple temperature sampling units to the output current precision control module, the inner environment temperature control module, the output voltage precision control module and the stability control module after signal distribution processing and comparison and/or weight distinguishing processing of the rough temperature signals to the temperature distinguishing and processing module;
the internal environment temperature control module is respectively electrically connected with the output current precision control module and the output voltage precision control module, can receive temperature signals corresponding to the internal environment after the distinguishing processing, and respectively outputs the temperature signals to the output current precision control module and the output voltage precision control module;
the output current precision control module can obtain temperature signals corresponding to the current according to the temperature signals respectively corresponding to the output current precision sampling resistor and the internal environment after the distinguishing processing;
the output voltage precision control module can obtain temperature signals corresponding to voltages according to the temperature signals respectively corresponding to the output voltage feedback circuit and the internal environment after the distinguishing processing;
the stability control module can obtain temperature signals corresponding to distribution parameters according to the temperature signals respectively corresponding to the power switch device, the magnetic element and the second-order filter circuit after the distinguishing processing. The stability control module has two functions, wherein when the stability control module is in a calibration loop, an output signal of the stability control module provides discrete input quantity for a temperature drift curve calibration module in a subsequent curve loading unit; and secondly, the real-time temperature data related to the stability control function is provided when the high-precision high-power converter works, which is an important parameter that the high-precision high-power converter can work stably.
In the temperature compensation device, the input signal distribution circuit includes: the high-speed analog switch multi-path serial selection circuit, the high-precision differential operational amplifier and the differential analog-to-digital converter are electrically connected.
In the above temperature compensation device, the curve loading unit includes:
the temperature drift calibration module, the temperature drift curve loading module and the distribution parameter curve loading module are connected with the temperature drift calibration module; wherein the content of the first and second substances,
the temperature drift curve calibration module is electrically connected with the precision and stability control unit and the temperature drift curve loading module, can automatically calibrate and follow the current temperature drift characteristic curve and the voltage temperature drift characteristic curve received by the precision and stability control unit through the communication with a remotely connected program-controlled voltmeter, a program-controlled ammeter, a programmable electronic load and an environmental test box, and sends the calibrated current temperature drift characteristic curve and the voltage temperature drift characteristic curve to the temperature drift curve loading module, and the characteristic quantities corresponding to the current temperature drift characteristic curve and the voltage temperature drift characteristic curve are respectively output current precision sampling resistance sigma R/R and output voltage sigma U/Uset；
The temperature drift curve loading module is respectively electrically connected with the temperature drift curve calibration module and the digital PWM adjusting unit and can load the current temperature drift characteristic curve and the voltage temperature drift characteristic curve received from the temperature drift curve calibration module to the digital PWM adjusting unit;
the distribution parameter curve loading module is respectively electrically connected with the precision and stability control unit and the digital PWM adjusting unit and can load the distribution parameter temperature drift characteristic curve received from the precision and stability control unit to the digital PWM adjusting unit; and the characteristic quantity corresponding to the distribution parameter temperature drift characteristic curve is distribution parameter equivalent series internal resistance (ESR).
In the temperature compensation device, the digital PWM adjusting unit may calibrate three characteristic quantities corresponding to the current temperature drift characteristic curve, the voltage temperature drift characteristic curve and the distribution parameter temperature drift characteristic curve according to the actual temperature value of the high-precision high-power converter (the actual temperature value is the temperature value measured by the multiple temperature sampling unit), to obtain three calibrated characteristic quantities, which are the output current precision sampling resistance value, the output voltage compensation value σ U and the distribution parameter equivalent series internal resistance ESR, and determine the output current set value, the output voltage set value and the digital loop compensation parameter k according to the fixed parameter and the topology characteristic parameter of the high-precision high-power converter according to the three calibrated characteristic quantitiesp、ki、kdAnd according to the obtained set value of the output current, the set value of the output voltage and the digital loop compensation parameter kp、ki、kdAnd generating a PWM (pulse-width modulation) adjusting signal, and controlling the high-precision high-power converter through the PWM adjusting signal. The output voltage and current of the high-precision high-power converter are less influenced by temperature, and the high-precision high-power converter has a low temperature drift coefficient.
The temperature compensation device can realize the calibration of current, voltage and distribution parameters, and further realize the temperature compensation control of the high-precision high-power converter under two working states of steady state and transient state, so that the high-precision high-power converter has lower temperature drift coefficient, and higher output precision is ensured.
Embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.
Referring to fig. 1, in the temperature compensation device, a multiple temperature sampling unit respectively performs temperature sampling on each key part of an output current precision sampling resistor, a loop control circuit, an output voltage feedback circuit, a power switch device, a magnetic element and a second-order filter circuit in a high-precision high-power converter to obtain a temperature signal;
because most of the output current precision sampling resistor and the power switch device are installed on an aluminum-based radiator, for the two tested devices, the temperature sensor can be packaged by TO-220 or TO-247, and the temperature sensor is arranged by adopting a radiator nearby crimping process, as shown in FIG. 2; the temperature sensor packaged by the lead can also be selected, and the temperature sensor is arranged by adopting a 'radiator point-burying process'.
Because the loop control circuit and the output voltage feedback circuit are concrete circuits welded on the printed circuit board, and the variation of the power loss of the circuits is small, two temperature sensors are arranged on each circuit to respectively measure the surface temperature of the printed circuit board and the temperature of the space around the circuit. The temperature sensor packages are SO-8 and TO-92, respectively, or similar packages. Finally, converting the influence factor through the weight of each circuit, wherein the weight is the ratio of the circuit error to the output voltage error; the measured temperature is decreased gradually by 'square of distance between the test point of the printed circuit board and a specific circuit', and compared with the ambient temperature, the measured temperature is taken as the maximum value.
Because the magnetic element and each key part of the second-order filter circuit, especially the converter output filter electrolytic capacitor is difficult to measure the surface temperature because of the cylindrical structure, the embodiment of the invention adopts the measuring process of 'flexible circuit pasting process', as shown in figure 3, specifically, a thick film flexible circuit board D with a locking contact F is arranged as the flexible circuit pasting structure, the surface-mounted and packaged temperature sensor E is arranged in the center of the circuit board by utilizing the thick film flexible circuit board, the bottom position of the temperature sensor in the circuit board is coated with insulating heat-conducting silicone grease in a hollow way, the thick film flexible circuit board is pasted on the surface of the electrolytic capacitor in a way of being vertical to the axial direction, and the surface temperature is firmly welded by the locking; the thick film flexible circuit board is inserted on the main circuit board through the golden finger port. The flexible circuit pasting process solves the problem that the surface temperature of the electrolytic capacitor is difficult to measure, has the advantages of high temperature measurement precision and high speed, and establishes a foundation for determining distribution parameters such as ESR (equivalent series resistance), ESL (electronic static var-equilibrium) and the like through surface temperature conversion.
Specifically, the circuit of the multiple temperature sampling unit is configured as shown in fig. 4 (but not limited to the circuit listed in fig. 4), because the types of the temperature sensors selected by the unit are different, the circuit needs to normalize the sampling voltage, because there are more than one temperature sensor for each measured key part or element, the circuit can obtain the finally measured temperature signal by using normalization processing methods such as maximum value, average value, weighted average, and the like, so as to prepare for further data processing of the accuracy and stability control unit.
In the above temperature compensation device, the accuracy and stability control unit includes: the device comprises an input signal distribution circuit, an output current precision control module, an internal environment temperature control module, an output voltage precision control module and a stability control module; the precision and stability control unit is mainly used for further carrying out deep ploughing processing and redistribution on the normalized rough signals input by the multiple temperature sampling units according to different actions and weights, and transmitting the normalized rough signals to the microprocessor of each module in a differential mode (the microprocessor can be independently arranged on each module, and can also be shared by the microprocessors). The input signal distribution circuit is electrically connected with the output current precision control module, the internal environment temperature control module, the output voltage precision control module and the stability control module respectively; the output current precision control module mainly processes two temperature signals of an output current precision sampling resistor and an internal environment; the output voltage precision control module is mainly used for processing three temperature signals of a loop control circuit, an output voltage feedback circuit and an internal environment; the stability control module mainly processes temperature signals of key parts such as a power switch device, a magnetic element, a second-order filter circuit and the like.
Specifically, the input signal distribution circuit of the precision and stability control unit is shown in fig. 5 (but not limited to the circuit shown in fig. 5); the circuit selects a plurality of signals in series through a high-speed analog switch, common mode rejection and signal source processing are carried out through a high-precision differential operational amplifier, and finally the signals are input into a differential analog-to-digital converter to be transmitted to a microprocessor. The design uses a set of circuit structure to complete 8 groups of signal transmission, and has the advantages of signal isolation, high common mode rejection ratio, simple structure and the like, and the transmission effect is shown in figure 6. As can be seen from fig. 6, the transmission period of each signal is only 20 μ s; in practical application, the circuit is used for different high-precision high-power converters, and if the signal sources of the temperature compensation device are more, the transmission period of each signal can be reduced to 1 mu s in the shortest way, so that the sampling transmission requirements of most power sources can be met.
In the above temperature compensation device, the curve loading unit includes: the temperature drift calibration module, the temperature drift curve loading module and the distribution parameter curve loading module are connected with the temperature drift calibration module; the curve loading unit is mainly used for loading three characteristic curves (namely a current temperature drift characteristic curve, an internal environment temperature drift characteristic curve and a voltage temperature drift characteristic curve) which change along with the temperature into the temperature compensation device; the main characteristic quantities corresponding to the three curves are respectively ' output current precision sampling resistance sigma R/R ' and ' output voltage sigma U/Uset"and" distribution parameter equivalent series internal resistance ESR ". The temperature drift curve calibration module is internally provided with a microprocessor calibration circuit which provides rich communication interfaces such as USB, LAN, GPIB, RS485 and the like, and is remotely connected with the program-controlled voltmeter, the program-controlled ammeter, the programmable electronic load and the environmental test chamber through the communication interfaces; the program-controlled voltmeter and the program-controlled current voltage read the actual output voltage and current values, and the environmental test chamber and the programmable electronic load provide different internal environmental temperature values for calibration; after entering a calibration mode, the system can actively communicate with a remotely connected program-controlled voltmeter, a program-controlled ammeter, a programmable electronic load and an environmental test chamber and automatically perform calibration and curve drawing; FIG. 7 is a schematic of an "output current precision sampling resistance σ R/R" curve that will be converted to recognizable tabular data and stored when loaded; all external conditions required for temperature compensation are available, and data is gathered to the digital PWM adjusting unit.
In the temperature compensation device, the digital PWM adjusting unit is a final calculating and executing unit; the digital PWM adjusting unit calibrates main characteristic quantities through an actual temperature value and a corresponding temperature drift curve, wherein the characteristic quantities comprise an output current precision sampling resistance value, an output voltage compensation value sigma U and a distribution parameter equivalent series internal resistance ESR parameter; the three main characteristic quantities determine an output current set value, an output voltage set value and a digital loop compensation parameter k according to a high-precision high-power converter, namely a fixed parameter and a topological characteristic parameterp、ki、kd"; the unit circuit generates PWM adjusting signals according to the three numerical values to drive the high-precision high-power converter, and finally the output voltage and current of the high-precision high-power converter have low temperature drift coefficient and high stability.
The intelligent temperature compensation device of the invention at least has the following beneficial effects:
1) the temperature coefficient index of the high-precision high-power converter during working at the limit environment temperature can be reduced to a level less than 20ppm, so that the precision of output voltage and current is greatly improved;
2) the control loop parameters can be automatically adjusted according to the corresponding relation between the measured temperature and the distribution parameters, so that the output stability is greatly improved in a high-temperature and low-temperature environment;
3) the adopted flexible circuit pasting structure solves the problems that the output filtering electrolytic capacitor of the converter is difficult to measure the surface temperature because of the cylindrical structure, and can not provide accurate parameters for temperature compensation control;
4) the device has the function of automatically calibrating the temperature drift curve, realizes the active communication with a remotely connected program-controlled voltmeter, a program-controlled ammeter, a programmable electronic load and an environmental test chamber, and automatically executes calibration and curve drawing;
5) all compensation and control processes can realize automation and intellectualization, and unattended operation can be realized.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
Claims (8)
1. An intelligent temperature compensation device for a high-precision high-power converter, comprising:
the device comprises a multiple temperature sampling unit, a precision and stability control unit, a curve loading unit and a digital PWM (pulse width modulation) adjusting unit; wherein the content of the first and second substances,
the multiple temperature sampling unit is provided with a plurality of groups of temperature sampling devices for connecting the high-precision high-power converter, can respectively acquire temperature signals of different circuit parts of the high-precision high-power converter, and respectively normalizes the acquired temperature signals of the different circuit parts of the high-precision high-power converter to form a rough temperature signal for output;
the precision and stability control unit is respectively electrically connected with the multiple temperature sampling unit and the curve loading unit, can perform signal distribution processing and distinguishing processing on each rough temperature signal corresponding to different circuit parts output by the multiple temperature sampling unit to respectively obtain temperature signals corresponding to current, an internal environment, voltage, a power switch device, a magnetic element and a second-order filter circuit, and forms a current temperature drift characteristic curve and a voltage temperature drift characteristic curve according to the temperature signals corresponding to the current and the voltage respectively and the temperature signals corresponding to the internal environment; forming a distribution parameter temperature drift characteristic curve according to the temperature signals corresponding to the power switch device, the magnetic element and the second-order filter circuit;
the curve loading unit is respectively electrically connected with the precision and stability control unit and the digital PWM adjusting unit, and can load the current temperature drift characteristic curve and the voltage temperature drift characteristic curve output by the precision and stability control unit and the distribution parameter temperature drift characteristic curve output by the precision and stability control unit to the digital PWM adjusting unit after calibrating the current temperature drift characteristic curve and the voltage temperature drift characteristic curve;
the digital PWM adjusting unit is respectively electrically connected with the curve loading unit and the high-precision high-power converter, can form PWM adjusting signals according to the current temperature drift characteristic curve, the voltage temperature drift characteristic curve and the distribution parameter temperature drift characteristic curve output by the curve loading unit, and controls the high-precision high-power converter through the PWM adjusting signals.
2. The intelligent temperature compensation device for high-precision high-power converter according to claim 1, wherein the multiple temperature sampling unit comprises:
the device comprises a precision current feedback module, an internal environment temperature feedback module, an output voltage feedback module, a power switch temperature module, a magnetic element temperature module and a second-order filtering temperature module; wherein the content of the first and second substances,
the precise current feedback module, the internal environment temperature feedback module, the output voltage feedback module, the power switch temperature module, the magnetic element temperature module and the second-order filtering temperature module are respectively provided with a group of temperature sampling devices;
the temperature sampling devices of the precision current feedback module, the internal environment temperature feedback module, the output voltage feedback module, the power switch temperature module, the magnetic element temperature module and the second-order filtering temperature module are respectively connected to the output current precision sampling resistor, the loop control circuit, the output voltage feedback circuit, the power switch device, the magnetic element and the second-order filtering circuit of the high-precision high-power converter, and can respectively collect temperature signals of circuit parts of the output current precision sampling resistor, the loop control circuit, the output voltage feedback circuit, the power switch device, the magnetic element and the second-order filtering circuit.
3. The intelligent temperature compensation device for high-precision high-power converter according to claim 2, wherein the precision current feedback module, the internal environment temperature feedback module, the output voltage feedback module, the power switch temperature module, the magnetic element temperature module and the second-order filtering temperature module all adopt temperature sampling circuits.
4. The intelligent temperature compensation device for the high-precision high-power converter according to claim 2 or 3, wherein the temperature sampling device of the precision current feedback module adopts a temperature sensor, and the temperature sensor is connected to the aluminum-based radiator connected with the output current precision sampling resistor through a radiator nearby compression joint or a radiator embedded point;
the temperature sampling device of the power switch temperature module adopts a temperature sensor which is connected to an aluminum-based radiator connected with the power switch device in a manner of nearby crimping of the radiator or embedding of the radiator;
the temperature sampling device of the internal environment temperature feedback module adopts two temperature sensors, wherein one temperature sensor is arranged on the surface of a printed circuit board of the loop control circuit, and the other temperature sensor is arranged in the space around the printed circuit board of the loop control circuit;
the temperature sampling device of the output voltage feedback module adopts two temperature sensors, wherein one temperature sensor is arranged on the surface of a printed circuit board of the output voltage feedback circuit, and the other temperature sensor is arranged in the space around the printed circuit board of the output voltage feedback circuit;
the temperature sampling device of the power switch temperature module adopts a temperature sensor with a hollow structure at the bottom, the temperature sensor is arranged on a flexible circuit attaching structure, and the flexible circuit attaching structure is wound on the surface of a power switch device with the temperature to be measured;
the temperature sampling device of the magnetic element temperature module adopts a temperature sensor with a hollow structure at the bottom, the temperature sensor is arranged on a flexible circuit attaching structure, and the flexible circuit attaching structure is wound on the surface of a magnetic element with the temperature to be measured;
the temperature sampling device of the second-order filtering temperature module adopts a temperature sensor with a hollow-out structure at the bottom, the temperature sensor is arranged on a flexible circuit attaching structure, and the flexible circuit attaching structure is wound on the surface of a filtering electrolytic capacitor of a second-order filtering circuit of which the temperature is measured.
5. The intelligent temperature compensation device for high-precision high-power converter according to any one of claims 1 to 3, wherein the precision and stability control unit comprises:
the device comprises an input signal distribution circuit, a temperature distinguishing and processing module, an output current precision control module, an internal environment temperature control module, an output voltage precision control module and a stability control module; wherein the content of the first and second substances,
the input signal distribution circuit is electrically connected with the multiple temperature sampling units, is respectively and electrically connected with the output current precision control module, the inner environment temperature control module, the output voltage precision control module and the stability control module through the temperature distinguishing and processing module, and can correspondingly distribute the rough temperature signals output by the multiple temperature sampling units to the output current precision control module, the inner environment temperature control module, the output voltage precision control module and the stability control module after signal distribution processing and comparison and/or weight distinguishing processing of the rough temperature signals to the temperature distinguishing and processing module;
the internal environment temperature control module is respectively electrically connected with the output current precision control module and the output voltage precision control module, can receive temperature signals corresponding to the internal environment after the distinguishing processing, and respectively outputs the temperature signals to the output current precision control module and the output voltage precision control module;
the output current precision control module can obtain temperature signals corresponding to the current according to the temperature signals respectively corresponding to the output current precision sampling resistor and the internal environment after the distinguishing processing;
the output voltage precision control module can obtain temperature signals corresponding to voltages according to the temperature signals respectively corresponding to the output voltage feedback circuit and the internal environment after the distinguishing processing;
the stability control module can obtain temperature signals corresponding to distribution parameters according to the temperature signals respectively corresponding to the power switch device, the magnetic element and the second-order filter circuit after the distinguishing processing.
6. The intelligent temperature compensation device for high-precision high-power converter according to claim 5, wherein the input signal distribution circuit comprises: the high-speed analog switch multi-path serial selection circuit, the high-precision differential operational amplifier and the differential analog-to-digital converter are electrically connected.
7. The intelligent temperature compensation device for high-precision high-power converter according to any one of claims 1 to 3, wherein the curve loading unit comprises:
the temperature drift calibration module, the temperature drift curve loading module and the distribution parameter curve loading module are connected with the temperature drift calibration module; wherein the content of the first and second substances,
the temperature drift curve calibration module is electrically connected with the precision and stability control unit and the temperature drift curve loading module, can automatically calibrate and follow the current temperature drift characteristic curve and the voltage temperature drift characteristic curve received by the precision and stability control unit through the communication with a remotely connected program-controlled voltmeter, a program-controlled ammeter, a programmable electronic load and an environmental test box, and sends the calibrated current temperature drift characteristic curve and the voltage temperature drift characteristic curve to the temperature drift curve loading module, and the characteristic quantities corresponding to the current temperature drift characteristic curve and the voltage temperature drift characteristic curve are respectively output current precision sampling resistance sigma R/R and output voltage sigma U/Uset；
The temperature drift curve loading module is respectively electrically connected with the temperature drift curve calibration module and the digital PWM adjusting unit and can load the current temperature drift characteristic curve and the voltage temperature drift characteristic curve received from the temperature drift curve calibration module to the digital PWM adjusting unit;
the distribution parameter curve loading module is respectively electrically connected with the precision and stability control unit and the digital PWM adjusting unit and can load the distribution parameter temperature drift characteristic curve received from the precision and stability control unit to the digital PWM adjusting unit; and the characteristic quantity corresponding to the distribution parameter temperature drift characteristic curve is distribution parameter equivalent series internal resistance (ESR).
8. The intelligent temperature compensation device for high-precision high-power converter according to any one of claims 1 to 3, wherein the digital PWM adjusting unit is capable of calibrating the current temperature drift characteristic curve, the voltage temperature drift characteristic curve and the distribution parameter temperature drift characteristic curve according to the current temperature drift characteristic curve, the voltage temperature drift characteristic curve and the distribution parameter temperature drift characteristic curve corresponding to the actual temperature value of the high-precision high-power converterObtaining three characteristic quantities corresponding to the digital temperature drift characteristic curve, wherein the obtained three calibrated characteristic quantities are respectively an output current precision sampling resistance value, an output voltage compensation value sigma U and a distribution parameter equivalent series internal resistance ESR, and determining according to the fixed parameters and the topological characteristic parameters of the high-precision high-power converter through the three calibrated characteristic quantities to obtain an output current set value, an output voltage set value and a digital loop compensation parameter kp、ki、kdAnd according to the obtained set value of the output current, the set value of the output voltage and the digital loop compensation parameter kp、ki、kdAnd generating a PWM (pulse-width modulation) adjusting signal, and controlling the high-precision high-power converter through the PWM adjusting signal.
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