CN113904557A - Automatic compensation device with high reliability and mutual hot backup of double buses and control method - Google Patents

Automatic compensation device with high reliability and mutual hot backup of double buses and control method Download PDF

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Publication number
CN113904557A
CN113904557A CN202111111069.8A CN202111111069A CN113904557A CN 113904557 A CN113904557 A CN 113904557A CN 202111111069 A CN202111111069 A CN 202111111069A CN 113904557 A CN113904557 A CN 113904557A
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signal
switching tube
unit
current
inductor
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CN202111111069.8A
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CN113904557B (en
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常军
肖思波
段奇锋
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SUZHOU WAGO DINGYI POWER SUPPLY CO Ltd
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SUZHOU WAGO DINGYI POWER SUPPLY CO Ltd
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
    • H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
    • H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
    • H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
    • H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/33569—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having several active switching elements
    • H02M3/33576—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having several active switching elements having at least one active switching element at the secondary side of an isolation transformer
    • H02M3/33584—Bidirectional converters
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J1/00—Circuit arrangements for dc mains or dc distribution networks
    • H02J1/06—Two-wire systems
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J9/00—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
    • H02M3/04—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters
    • H02M3/10—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M3/145—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M3/155—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/156—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
    • Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

The invention provides an automatic compensation device with high reliability and mutual hot backup of double buses, which comprises an open-loop bidirectional LLC conversion circuit, wherein the open-loop bidirectional LLC conversion circuit is simultaneously connected with a BUCK1 conversion circuit and a BUCK2 conversion circuit, and the BUCK1 conversion circuit and the BUCK2 conversion circuit are controlled by a double-port voltage analog control circuit based on mixed inductive current sampling. The problem of the reliability that two generating lines are each other for hot two-way DC-DC converter is solved in this application, adopt two BUCK and two-way open-loop LLC converter to constitute and mix two-way DC-DC converter, and cooperate its peculiar dual-port voltage analog control circuit based on mixing the inductive current sampling, realize the high reliability of quick output and compromise the system.

Description

Automatic compensation device with high reliability and mutual hot backup of double buses and control method
Technical Field
The invention relates to the technical field of direct-current power supply systems, in particular to a high-reliability automatic compensation device with double buses as mutual hot backup and a control method.
Background
In order to ensure the safe operation of the power system, the control and protection equipment of the power plant and the transformer substation are powered by direct current power supplies.
In order to further improve the power supply reliability of the system, two sets of direct current power supply systems are generally subjected to mutual hot backup, and when one set of system has a problem in power supply, the other set of system can provide the system with the other set of power supply. And the two sets of direct current power supply systems need complete electrical isolation, so that the two sets of direct current power supplies are generally communicated by adopting bidirectional DC-DC. And the added bidirectional DC-DC needs to have higher reliability requirement, otherwise, the reliability of the original system is reduced.
In the existing bidirectional DC-DC scheme in the power electronic topology, the input stage is generally a full-bridge topology, and when an upper switch tube and a lower switch tube in series in the full-bridge topology fail, the input stage is short-circuited, so that even if a fuse is fused, a larger impact current is generated, and the power supply reliability of a system is influenced.
In addition, the bidirectional DC-DC also needs to have functions of bidirectional fast switching, dual-port voltage control, bidirectional parallel operation current sharing control, and the like, and needs complex logic judgment and time sequence control, and the increase of system complexity also reduces the reliability of the system.
Disclosure of Invention
The application simultaneously provides an automatic compensation device with high reliability and mutual hot backup of double buses and a control method of adaptation of the automatic compensation device, the problem of reliability of mutual hot backup of the double buses of a bidirectional DC-DC converter is solved, a hybrid bidirectional DC-DC converter is formed by adopting a double BUCK and a bidirectional open-loop LLC converter, and the hybrid bidirectional DC-DC converter is matched with a special analog control circuit of the hybrid bidirectional DC-DC converter, so that quick output is realized and high reliability of the system is considered.
In order to solve the technical problems, the technical scheme adopted by the invention is as follows:
the automatic compensation device comprises an open-loop bidirectional LLC conversion circuit, wherein the open-loop bidirectional LLC conversion circuit is simultaneously connected with a BUCK1 conversion circuit and a BUCK2 conversion circuit, and the BUCK1 conversion circuit and the BUCK2 conversion circuit are controlled by a dual-port voltage analog control circuit based on mixed inductive current sampling.
Further, the dual-port voltage analog control circuit based on the mixed inductor current sampling comprises a first summing unit, a second summing unit, a third summing unit, a first PID unit, a second PID unit, a PI unit, a maximum gating unit, an averaging unit, a precise rectifying unit, a PWM generating unit, a parallel pull-down resistor and a parallel diode;
the PWM generating unit generates PWM control signals for driving switching tubes of the BUCK1 conversion circuit and the BUCK2 conversion circuit;
the output end of the PI unit is connected with the input end of the PWM generating unit;
two input ends of the third summing unit are respectively connected with a parallel operation signal Ib and an inductive current conditioning signal ILabs, and an output end of the third summing unit generates an error signal Ierr which is connected with an input end of the PI unit;
the input end of the precision rectifying unit is connected with an inductive current average value signal ILavg, and an output end of the precision rectifying unit generates an inductive current conditioning signal ILabs which is connected with one input end of the third summing unit;
the input end of the averaging unit is connected with an inductive current signal IL1 and an inductive current signal IL2, and the output end of the averaging unit generates an inductive current average value signal ILavg which is connected with the input end of the precision rectifying unit;
the two input ends of the maximum gating unit are respectively connected with an inductive current given signal Ig1 and an inductive current given signal Ig2, the output end of the maximum gating unit generates a maximum current given signal Ig, the maximum current given signal Ig is connected with the anode of the parallel diode, the cathode of the parallel diode outputs a parallel signal Ib, and the cathode of the parallel diode is connected with GND through a parallel pull-down resistor;
the input end of the first PID unit is connected with an error signal Verr1, and the output end of the first PID unit generates an inductive current given signal Ig1 which is connected with one input end of the maximum gating unit;
the input end of the second PID unit is connected with an error signal Verr2, and the output end of the second PID unit generates an inductive current given signal Ig2 which is connected with one input end of the maximum gating unit;
two input ends of the first summing unit are respectively connected with a voltage given signal VG and a bus V1 voltage feedback signal V1f, and the output of the first summing unit generates an error signal Verr1 which is connected with the input end of the first PID unit;
two input ends of the second summation unit are respectively connected with a voltage given signal VG and a bus V2 voltage feedback signal V2f, and the output of the second summation unit generates an error signal Verr2 which is connected with the input end of the second PID unit.
Further, the inductor current average signal ILavg is equal to the average of the inductor current signal IL1 and the inductor current signal IL 2;
the maximum current given signal Ig is equal to the larger of the inductor current given signal Ig1 and the inductor current given signal Ig 2.
Preferably, the open-loop bidirectional LLC conversion circuit includes two groups of H-bridges, and a transformer T1, a resonant capacitor C7, a resonant capacitor C8, a bus capacitor C5, a bus capacitor C6, a damping network 1, and a damping network 2 connected between the two groups of H-bridges;
the first group of H-bridge consists of two groups of half-bridges, wherein a switching tube Q3 and a switching tube Q4 form one group of half-bridges, and a switching tube Q5 and a switching tube Q6 form the other group of half-bridges;
the second group of H bridges consists of two groups of half bridges, wherein a switching tube Q7 and a switching tube Q8 form one group of half bridges, and a switching tube Q9 and a switching tube Q10 form the other group of half bridges;
the switching tube Q3 and the switching tube Q5 are both the upper tubes of the half bridge, and are connected with the positive electrode of a bus Vm 1;
the switching tube Q4 and the switching tube Q6 are both lower tubes of the half bridge, and are connected with the negative electrode of a bus Vm 2;
the switching tube Q7 and the switching tube Q9 are both the upper tubes of the half bridge, and are connected with the positive electrode of a bus Vm 2;
the switching tube Q8 and the switching tube Q10 are both lower tubes of the half bridge, and are connected with the negative electrode of a bus Vm 1;
the switching tube Q3, the switching tube Q6, the switching tube Q7 and the switching tube Q10 have the same driving signal DR 1;
the switching tube Q4, the switching tube Q5, the switching tube Q8 and the switching tube Q9 have the same driving signal DR 2;
the drive signal DR1 and the drive signal DR2 are complementary drive signals with dead zones;
the transformer output end 1 of the transformer T1 is connected with the half-bridge midpoint consisting of the switching tube Q3 and the switching tube Q4 through the resonant capacitor C7;
the transformer output end 3 of the transformer T1 is connected with the half-bridge midpoint consisting of the switching tube Q7 and the switching tube Q8 through the resonant capacitor C8;
the transformer output end 2 of the transformer T1 is connected with a half-bridge midpoint formed by the switching tube Q5 and the switching tube Q6;
the transformer output end 4 of the transformer T1 is connected with a half-bridge midpoint formed by the switching tube Q9 and the switching tube Q10;
the transformer T1 comprises two isolated windings, wherein two transformer output ends of one winding are a transformer output end 1 and a transformer output end 2, two transformer output ends of the other winding are a transformer output end 3 and a transformer output end 4, and the transformer output end 1 and the transformer output end 3 are homonymous ends;
the bus capacitor C5 is connected with a first group of H bridge buses Vm 1;
the bus capacitor C6 is connected with a second group of H bridge buses Vm 2;
the damping network 1 is connected with a first group of H bridge buses Vm 1;
the damping network 2 is connected to a second set of H-bridge bus bars Vm 2.
Preferably, the damping network 1 includes a resistor R1 and a capacitor C3, the resistor R1 is connected in series with the capacitor C3, the damping network 2 includes a resistor R2 and a capacitor C4, and the resistor R2 is connected in series with the capacitor C4.
Preferably, the BUCK1 conversion circuit comprises a capacitor C1, a switching tube Q1, a diode D1, an inductor L1, a first voltage sensor and a first current sensor;
one end of the capacitor C1 is connected with the anode of the switching tube Q1 and is also connected with the anode of the input power supply V1, and the other end of the capacitor C1 is connected with the cathode of the input power supply V1;
the cathode of the diode D1 is connected with the cathode of the switch tube Q1 and is also connected with one end of the inductor L1, and the anode of the diode D1 is connected with the cathode of the input power supply V1;
the other end of the inductor L1 is connected with the positive electrode of a bus Vm 1;
the input end of the first voltage sensor is connected with the positive electrode and the negative electrode of an input power supply V1, and the first voltage sensor outputs a voltage feedback signal V1 f;
the first current sensor collects an inductor L1 current, and the first current sensor outputs an inductor current signal IL 1.
Further, the BUCK2 conversion circuit comprises a capacitor C2, a switching tube BUCK switching tube Q2, a diode D2, an inductor L2, a second voltage sensor and a second current sensor;
one end of the capacitor C2 is connected with the anode of the switching tube Q2 and the anode of the input V2, and the other end of the capacitor C2 is connected with the cathode of the input power supply V2;
the cathode of the diode D2 is connected with the cathode of the switch tube Q2 and is also connected with one end of the inductor L2, and the anode of the diode D2 is connected with the cathode of the input power supply V2;
the other end of the inductor L2 is connected with the positive electrode of a bus Vm 2;
the input end of the second voltage sensor is connected with the positive electrode and the negative electrode of an input power supply V2, and the second voltage sensor generates a voltage feedback signal V2 f;
the second current sensor collects the current of the inductor L2, and the output end of the second current sensor generates an inductor current signal IL 2.
Further, the invention also provides an automatic compensation control method of the automatic compensation device with high reliability and mutual hot backup of double buses, which comprises the following steps:
step 1: obtaining an error signal Verr1 by subtracting a voltage given signal VG from a bus V1 voltage feedback signal V1 f;
step 2: an error signal Verr1 passes through a first PID unit to obtain an inductive current given signal Ig 1;
and step 3: the voltage given signal VG is subtracted from a voltage feedback signal V2f of a line V2 to obtain an error signal Verr 2;
and 4, step 4: the error signal Verr2 passes through a second PID unit to obtain an inductive current given signal Ig 2;
and 5: comparing the inductance current given signal Ig1 with the inductance current given signal Ig2 to obtain a maximum current given signal Ig;
step 6: obtaining a parallel operation signal Ib by a maximum current given signal Ig through a parallel operation diode;
and 7: averaging the inductive current signal IL1 and the inductive current signal IL2 to obtain an inductive current average value signal ILavg;
and 8: obtaining an inductive current conditioning signal ILabs by solving an absolute value of the inductive current average value signal ILavg;
and step 9: obtaining an error signal Ierr by subtracting the parallel operation signal Ib from the inductive current conditioning signal ILabs;
step 10: the error signal Ierr passes through a PI unit to obtain a control signal Com;
step 11: the control signal Com passes through the PWM generating unit to obtain a PWM control signal;
step 12: the PWM control signal drives a BUCK1 conversion circuit switching tube Q1 and a BUCK2 conversion circuit switching tube BUCK switching tube Q2.
The invention has the beneficial effects that:
the application simultaneously provides an automatic compensation device with high reliability and mutual hot backup of double buses and a control method of adaptation of the automatic compensation device, the problem of reliability of mutual hot backup of the double buses of a bidirectional DC-DC converter is solved, a hybrid bidirectional DC-DC converter is formed by adopting a double BUCK and a bidirectional open-loop LLC converter, and the hybrid bidirectional DC-DC converter is matched with a special analog control circuit of the hybrid bidirectional DC-DC converter, so that quick output is realized and high reliability of the system is considered.
1. According to the invention, the double-port input stage is BUCK, and even if a switching tube of the BUCK circuit fails and is directly connected, the intermediate stage open-loop bidirectional LLC conversion circuit protects; when the switch tube of the intermediate-stage open-loop bidirectional LLC conversion circuit is failed and directly connected, the BUCK can be used for current limiting protection, overlarge surge current cannot be generated, and the influence on an input port is avoided, so that the reliability of the system can be greatly improved.
2. The invention adopts the absolute value of the bidirectional inductive current as the feedback of the current inner loop, does not need to control the current direction, and can realize the automatic current sharing without master and slave by only connecting the parallel operation signals Ib of all the modules.
3. The dual-port voltage control of the invention is simple, when the voltages of the two ports are both greater than the set voltage, the voltage feedback signal V1f and the voltage feedback signal V2f are both greater than the voltage given signal VG, therefore, the PID regulator is in a negative saturation state, the duty ratio D of the PWM signal is 0, the bus voltage of the intermediate-stage open-loop bidirectional LLC conversion circuit is zero, and the service life of the intermediate-stage open-loop bidirectional LLC conversion circuit under heat reserve can be greatly prolonged. When any one end voltage is lower than a given voltage signal VG, the device can automatically close the loop to stabilize the output voltage of the loop at a set value, automatically complete the no-voltage compensation process, and does not need complex time sequence and logic judgment, and the voltage of the two ports can be simultaneously controlled by the method.
4. The invention uses the mixed inductance current inner loop for control, namely, BUCK inductance currents on the left side and the right side of the open-loop bidirectional LLC conversion circuit are averaged and processed in absolute value, and then are used as feedback signals of the inductance current inner loop, and the voltage closed loop can always ensure stability no matter the direction of the current.
Drawings
FIG. 1 is a schematic diagram of an automatic compensation device with high reliability and mutual hot backup of double buses;
FIG. 2 is a simplified equivalent schematic of the main circuit;
FIG. 3 is a simplified schematic equivalent diagram of the current flow direction from V1 to V2;
FIG. 4 is a simplified schematic equivalent diagram of the current flow direction from V2 to V1;
FIG. 5 illustrates dynamic loading waveforms for Vm1, Vm2, and resonant current without an RC damping network;
FIG. 6 Vm1, Vm2 and resonant current dynamic loading waveforms with RC damping networks;
FIG. 7 waveforms for the switching processes Vm1, Vm2, and V2;
FIG. 8 is a control block diagram of a differential-less current sharing circuit;
FIG. 9 is a control block diagram of an anti-interference isolated differential-free current-sharing circuit;
a description of the reference numerals;
101-a first voltage sensor, 102-a second voltage sensor, 103-a first current sensor, 104-a second current sensor, 111-a first summing unit, 112-a second summing unit, 113-a first PID unit, 114-a second PID unit, 115-a maximum gating unit, 116-an averaging unit, 117-a fine rectification unit, 118-a third summing unit, 119-a PI unit, 120-a PWM generation unit, 121-a parallel pull-down resistor, 122-a parallel diode.
Detailed Description
The following describes in detail an automatic compensation device with high reliability and mutual hot backup of double buses according to the present invention with reference to the accompanying drawings and the specific implementation method.
Fig. 1, 8 and 9 show circuit diagrams of an automatic compensation device with high reliability and mutual hot backup of double buses according to the present invention.
The working process of the system is described in detail as follows:
the intermediate stage DCDC is in an open-loop working mode, the working frequency is the resonant frequency of the LLC, the switching tubes Q3-Q10 are always in the zero-voltage on and zero-current off states, and energy flows bidirectionally, the gain is 1, so the bus V1m is equal to the bus V2m in voltage, which may be equivalent to that shown in fig. 2.
When a current flows from V1 to V2, the BUCK converter composed of capacitor C1, switching tube Q1, diode D1, and inductor L1 operates, and switching tube BUCK switching tube Q2 is always in the on state, and diode D2 is always in the off state, which can be equivalent to that shown in fig. 3, where the duty ratio of the PWM signal is D, and then V2/V1 is D.
When a current flows from V2 to V1, the BUCK converter composed of the capacitor C2, the switching tube BUCK switching tube Q2, the diode D2, and the inductor L2 operates, and the switching tube Q1 is always in the on state, and the diode D1 is always in the off state regardless of the PWM signal, which can be equivalent to that shown in fig. 4, and when the duty ratio of the PWM signal is D, the relationship of V1/V2 is D.
From this, it can be seen that when V1> D × V1> V2, current flows in the forward direction to V2; when V2> D × V2> V1, current flows in the reverse direction to V1; when V1> V2> D V1 or V2> V1> D V2, the current is 0. It can be concluded that the current direction is only related to the voltage of the two ports, and the current only flows from the high voltage side to the low voltage side, so that the current circulating phenomenon does not occur when the modules are connected in parallel, and the current direction does not need to be considered in the control, so that the precise rectifying unit 117 is added in the current conditioning circuit.
Damping network addition purpose:
since the intermediate-stage bidirectional DCDC is in the open-loop resonant operation mode, experiments show that in the operation mode, when the current suddenly changes, the inherent oscillation process of the bidirectional DCDC, i.e., the periodic oscillation of the transformer current, is excited, as shown in fig. 5, the oscillation frequency of the bidirectional DCDC is related to the bus capacitors C5 and C6 at the two ends of the bidirectional DCDC, and is related to the resonance of the LLC and the switching frequency of the bidirectional DCDC, the smaller the bus capacitor is, the stronger the oscillation is, and the closer the switching frequency is to the LLC resonance frequency, the stronger the oscillation is. In order to improve the response speed of the system, the capacitance capacity of the bus is limited, and at the same time, the soft switching effect of the switching tube is ensured, and the switching frequency is strictly matched with the LLC resonant frequency, so that the problem can be solved only by other means. The intrinsic oscillation of the bidirectional DCDC is attenuated by connecting an RC damping network to the bus capacitor C5 and the bus capacitor C6 in parallel, respectively, as shown in fig. 6.
The working principle of the mixed inductor current sampling is as follows:
in order to eliminate the LC resonance peak of the main power circuit and achieve the purpose of improving the system bandwidth, an inductance current inner loop is required to be added, and the invention is characterized in that the output is a 4-order system of LCLC, so that the current of the two inductors is weighted average processed, namely the average value of an inductance current signal IL1 and an inductance current signal IL2 is adopted for control, so that the current of the two inductors can participate in the control, meanwhile, the characteristics of control objects are completely the same no matter the current is positive or negative, one current inner loop can be shared, the control of the system is greatly simplified, in addition, in order to further eliminate the symbol of inductance current control quantity, the averaged inductance current signal (IL1+ IL2)/2 is precisely rectified to obtain the final current feedback conditioning signal (IL1+ IL 2)/2.
The working principle of the dual-port voltage control is as follows:
the invention is used for mutual hot backup of two port power supplies, when the voltage of any one end power supply drops, the system can automatically run, and the voltage of the dropped port is stabilized at a set voltage value. The invention has two voltage loops: a forward voltage loop and a reverse voltage loop;
the two voltage loops have the same voltage setting signal VG, when V1f > V2f > VG or V2f > V1f > VG, the two voltage loops are in negative saturation, Ig1<0 and a second inductor current given signal Ig2<0, the current after passing through the maximum gating unit 115 is given Ig <0, the inductor current inner loop is in negative saturation, the duty ratio of PWM is always 0, and at the moment, both the BUCK1 switch tube Q1 and the BUCK2 switch tube Q2 are in an off state, so that voltages of two ports do not influence each other.
When V1f > VG > V2f, the V1f voltage loop is negatively saturated, the Ig1<0, the V2f voltage loop is controlled, the second inductor current given signal Ig2>0, the current given Ig after passing through the maximum gating unit 115 is the second inductor current given signal Ig2>0, the inductor current inner loop is in a controlled state, and the PWM duty ratio D >0 stabilizes the port voltage V2 at the setting value corresponding to VG.
When V2f > VG > V1f, the V2f voltage loop is negatively saturated, the second inductor current setting signal Ig2<0, the V1f voltage loop is controlled, Ig1>0, the current after passing through the maximum gating unit 115 is set to Ig1>0, the inductor current inner loop is in a controlled state, and the duty ratio D of PWM >0, at this time, the port voltage V1 is stabilized at the setting value corresponding to VG.
When VG > V2f > V1f, the two voltage loops are both in positive saturation, Ig1 is the maximum value and the second inductor current given signal Ig2 is the maximum value, the current given Ig after passing through the maximum gating unit 115 is the maximum value, the inductor current inner loop is in positive saturation, the duty ratio of PWM is always 100%, at this time, both the BUCK1 switching tube Q1 and the BUCK2 switching tube Q2 are in a conducting state, and at this time, the voltages of the two ports are equal.
Examples are:
as shown in fig. 7, in the initial state, V1-220V, V2-220V, and VG set to 200V; at the 30ms, the power supply V2 falls, the voltage of the port output capacitor support V2 slowly falls, at the 31ms, the regulator starts to respond and increases the duty ratio of the PWM signal, the middle-stage buses Vm1 and Vm2 start to build, and at the 33ms, the voltage of the V2 port does not fall and is stabilized to the set value of 200V.
In the description provided herein, numerous specific details are set forth. It is understood, however, that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.
Similarly, it should be appreciated that in the foregoing description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. However, the disclosed method should not be interpreted as reflecting an intention that: that the invention claimed requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention.
Those skilled in the art will appreciate that the modules or units or groups of devices in the examples disclosed herein may be arranged in a device as described in this embodiment, or alternatively may be located in one or more devices different from the devices in this example. The modules in the foregoing examples may be combined into one module or may be further divided into multiple sub-modules.
Those skilled in the art will appreciate that the modules in the device in an embodiment may be adaptively changed and disposed in one or more devices different from the embodiment. Modules or units or groups in embodiments may be combined into one module or unit or group and may furthermore be divided into sub-modules or sub-units or sub-groups. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and all of the processes or elements of any method or apparatus so disclosed, may be combined in any combination, except combinations where at least some of such features and/or processes or elements are mutually exclusive. Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise.
Furthermore, those skilled in the art will appreciate that while some embodiments described herein include some features included in other embodiments, rather than other features, combinations of features of different embodiments are meant to be within the scope of the invention and form different embodiments. For example, in the claims, any of the claimed embodiments may be used in any combination.
Furthermore, some of the described embodiments are described herein as a method or combination of method elements that can be performed by a processor of a computer system or by other means of performing the described functions. A processor with the necessary instructions for implementing the method or method elements thus forms a means for implementing the method or method elements. Further, the elements of the apparatus embodiments described herein are examples of the following apparatus: the apparatus is used to implement the functions performed by the elements for the purpose of implementing the invention.
The various techniques described herein may be implemented in connection with hardware or software or, alternatively, with a combination of both. Thus, the methods and apparatus of the present invention, or certain aspects or portions thereof, may take the form of program code (i.e., instructions) embodied in tangible media, such as floppy diskettes, CD-ROMs, hard drives, or any other machine-readable storage medium, wherein, when the program is loaded into and executed by a machine, such as a computer, the machine becomes an apparatus for practicing the invention.
In the case of program code execution on programmable computers, the computing device will generally include a processor, a storage medium readable by the processor (including volatile and non-volatile memory and/or storage elements), at least one input device, and at least one output device. Wherein the memory is configured to store program code; the processor is configured to perform the method of the invention according to instructions in said program code stored in the memory.
By way of example, and not limitation, computer readable media may comprise computer storage media and communication media. Computer readable media include computer storage media and communication media. Computer storage media store information such as computer readable instructions, data structures, program modules or other data. Communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media. Combinations of any of the above are also included within the scope of computer readable media.
As used herein, unless otherwise specified the use of the ordinal adjectives "first", "second", "third", etc., to describe a common object, merely indicate that different instances of like objects are being referred to, and are not intended to imply that the objects so described must be in a given sequence, either temporally, spatially, in ranking, or in any other manner.
While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this description, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as described herein. Furthermore, it should be noted that the language used in the specification has been principally selected for readability and instructional purposes, and may not have been selected to delineate or circumscribe the inventive subject matter. Accordingly, many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the appended claims. The present invention is disclosed by way of illustration and not limitation with respect to the scope of the invention, which is defined by the claims that follow.

Claims (8)

1. The automatic compensation device is characterized by comprising an open-loop bidirectional LLC conversion circuit, wherein the open-loop bidirectional LLC conversion circuit is simultaneously connected with a BUCK1 conversion circuit and a BUCK2 conversion circuit, and the BUCK1 conversion circuit and the BUCK2 conversion circuit are controlled by a double-port voltage analog control circuit based on mixed inductive current sampling.
2. The automatic compensation device for mutual hot backup of the high-reliability double buses of claim 1, wherein the dual-port voltage analog control circuit based on the mixed inductor current sampling comprises a first summing unit (111), a second summing unit (112), a third summing unit (118), a first PID unit (113), a second PID unit (114), a PI unit (119), a maximum gating unit (115), an averaging unit (116), a precision rectifying unit (117), a PWM generating unit (120), a parallel pull-down resistor (121) and a parallel diode (122);
the PWM generating unit (120) generates PWM control signals for driving switching tubes of the BUCK1 converting circuit and the BUCK2 converting circuit;
the output end of the PI unit (119) is connected with the input end of the PWM generating unit (120);
two input ends of the third summing unit (118) are respectively connected with a parallel signal Ib and an inductive current conditioning signal ILabs, and an output end of the third summing unit (118) generates an error signal Ierr which is connected with an input end of the PI unit (119);
the input end of the precision rectifying unit (117) is connected with an inductive current average value signal ILavg, and the output end of the precision rectifying unit (117) generates an inductive current conditioning signal ILabs which is connected with one input end of the third summing unit (118);
the input end of the averaging unit (116) is connected with an inductor current signal IL1 and an inductor current signal IL2, and the output end of the averaging unit (116) generates an inductor current average value signal ILavg which is connected with the input end of the precision rectifying unit (117);
two input ends of the maximum gating unit (115) are respectively connected with an inductor current given signal Ig1 and an inductor current given signal Ig2, an output end of the maximum gating unit (115) generates a maximum current given signal Ig, the maximum current given signal Ig is connected with an anode of the parallel diode (122), a cathode of the parallel diode (122) outputs a parallel signal Ib, and a cathode of the parallel diode (122) is connected with GND through the parallel pull-down resistor (121);
the input end of the first PID unit (113) is connected with an error signal Verr1, and the output end of the first PID unit (113) generates an inductance current given signal Ig1 which is connected with one input end of the maximum gating unit (115);
the input end of the second PID unit (114) is connected with an error signal Verr2, and the output end of the second PID unit (114) generates an inductor current given signal Ig2 which is connected with one input end of the maximum gating unit (115);
two input ends of the first summing unit (111) are respectively connected with a voltage given signal VG and a bus V1 voltage feedback signal V1f, and the output of the first summing unit (111) generates an error signal Verr1 which is connected with the input end of the first PID unit (113);
two input ends of the second summation unit (112) are respectively connected with a voltage given signal VG and a bus V2 voltage feedback signal V2f, and the output of the second summation unit (112) generates an error signal Verr2 which is connected with the input end of a second PID unit (114).
3. The automatic compensation device for mutual hot backup of high reliability double buses as claimed in claim 2,
the inductor current average signal ILavg is equal to the average of the inductor current signal IL1 and the inductor current signal IL 2;
the maximum current given signal Ig is equal to the larger of the inductor current given signal Ig1 and the inductor current given signal Ig 2.
4. The automatic compensation device for mutual hot standby of high reliability double buses as claimed in claim 2 or 3, wherein the open-loop bidirectional LLC conversion circuit comprises two sets of H-bridges, and a transformer T1, a resonant capacitor C7, a resonant capacitor C8, a bus capacitor C5, a bus capacitor C6, a damping network 1 and a damping network 2 connected between the two sets of H-bridges;
the first group of H-bridge consists of two groups of half-bridges, wherein a switching tube Q3 and a switching tube Q4 form one group of half-bridges, and a switching tube Q5 and a switching tube Q6 form the other group of half-bridges;
the second group of H bridges consists of two groups of half bridges, wherein a switching tube Q7 and a switching tube Q8 form one group of half bridges, and a switching tube Q9 and a switching tube Q10 form the other group of half bridges;
the switching tube Q3 and the switching tube Q5 are both the upper tubes of the half bridge, and are connected with the positive electrode of a bus Vm 1;
the switching tube Q4 and the switching tube Q6 are both lower tubes of the half bridge, and are connected with the negative electrode of a bus Vm 2;
the switching tube Q7 and the switching tube Q9 are both the upper tubes of the half bridge, and are connected with the positive electrode of a bus Vm 2;
the switching tube Q8 and the switching tube Q10 are both lower tubes of the half bridge, and are connected with the negative electrode of a bus Vm 1;
the switching tube Q3, the switching tube Q6, the switching tube Q7 and the switching tube Q10 have the same driving signal DR 1;
the switching tube Q4, the switching tube Q5, the switching tube Q8 and the switching tube Q9 have the same driving signal DR 2;
the drive signal DR1 and the drive signal DR2 are complementary drive signals with dead zones;
the transformer output end 1 of the transformer T1 is connected with the half-bridge midpoint consisting of the switching tube Q3 and the switching tube Q4 through the resonant capacitor C7;
the transformer output end 3 of the transformer T1 is connected with the half-bridge midpoint consisting of the switching tube Q7 and the switching tube Q8 through the resonant capacitor C8;
the transformer output end 2 of the transformer T1 is connected with a half-bridge midpoint formed by the switching tube Q5 and the switching tube Q6;
the transformer output end 4 of the transformer T1 is connected with a half-bridge midpoint formed by the switching tube Q9 and the switching tube Q10;
the transformer T1 comprises two isolated windings, wherein two transformer output ends of one winding are a transformer output end 1 and a transformer output end 2, two transformer output ends of the other winding are a transformer output end 3 and a transformer output end 4, and the transformer output end 1 and the transformer output end 3 are homonymous ends;
the bus capacitor C5 is connected with a first group of H bridge buses Vm 1;
the bus capacitor C6 is connected with a second group of H bridge buses Vm 2;
the damping network 1 is connected with a first group of H bridge buses Vm 1;
the damping network 2 is connected to a second set of H-bridge bus bars Vm 2.
5. The automatic compensation device for mutual hot backup of high reliability double buses as claimed in claim 4, wherein: the damping network 1 comprises a resistor R1 and a capacitor C3, the resistor R1 is connected with the capacitor C3 in series, the damping network 2 comprises a resistor R2 and a capacitor C4, and the resistor R2 is connected with the capacitor C4 in series.
6. The automatic compensation device for mutual hot backup of high reliability double buses as claimed in claim 5, wherein: the BUCK1 conversion circuit comprises a capacitor C1, a switching tube Q1, a diode D1, an inductor L1, a first voltage sensor (101) and a first current sensor (103);
one end of the capacitor C1 is connected with the anode of the switching tube Q1 and is also connected with the anode of the input power supply V1, and the other end of the capacitor C1 is connected with the cathode of the input power supply V1;
the cathode of the diode D1 is connected with the cathode of the switching tube Q1 and is also connected with one end of the inductor L1, and the anode of the diode D1 is connected with the cathode of the input power supply V1;
the other end of the inductor L1 is connected with the positive electrode of a bus Vm 1;
the input end of the first voltage sensor (101) is connected with the positive pole and the negative pole of an input power supply V1, and the first voltage sensor (101) outputs a voltage feedback signal V1 f;
the first current sensor (103) collects an inductor L1 current, and the first current sensor (103) outputs an inductor current signal IL 1.
7. The automatic compensation device for mutual hot backup of high reliability double buses as claimed in claim 6, wherein:
the BUCK2 conversion circuit comprises a capacitor C2, a switching tube BUCK switching tube Q2, a diode D2, an inductor L2, a second voltage sensor (102) and a second current sensor (104);
one end of the capacitor C2 is connected with the anode of the switching tube Q2 and the anode of the input V2, and the other end of the capacitor C2 is connected with the cathode of the input power supply V2;
the cathode of the diode D2 is connected with the cathode of the switching tube Q2 and is also connected with one end of the inductor L2, and the anode of the diode D2 is connected with the cathode of the input power supply V2;
the other end of the inductor L2 is connected with the positive electrode of a bus Vm 2;
the input end of the second voltage sensor (102) is connected with the positive pole and the negative pole of an input power supply V2, and the second voltage sensor (102) generates a voltage feedback signal V2 f;
the second current sensor (104) collects the current of the inductor L2, and the output end of the second current sensor (104) generates an inductor current signal IL 2.
8. The automatic compensation control method of the automatic compensation device for mutual hot backup of the high-reliability double buses based on claim 6 is characterized by comprising the following steps:
step 1: obtaining an error signal Verr1 by subtracting a voltage given signal VG from a bus V1 voltage feedback signal V1 f;
step 2: an error signal Verr1 passes through a first PID unit (113) to obtain an inductive current given signal Ig 1;
and step 3: the voltage given signal VG is subtracted from a voltage feedback signal V2f of a line V2 to obtain an error signal Verr 2;
and 4, step 4: the error signal Verr2 passes through a second PID unit (114) to obtain an inductive current given signal Ig 2;
and 5: comparing the inductance current given signal Ig1 with the inductance current given signal Ig2 to obtain a maximum current given signal Ig;
step 6: the maximum current given signal Ig obtains a parallel operation signal Ib through a parallel operation diode (122);
and 7: averaging the inductive current signal IL1 and the inductive current signal IL2 to obtain an inductive current average value signal ILavg;
and 8: obtaining an inductive current conditioning signal ILabs by solving an absolute value of the inductive current average value signal ILavg;
and step 9: obtaining an error signal Ierr by subtracting the parallel operation signal Ib from the inductive current conditioning signal ILabs;
step 10: the error signal Ierr passes through a PI unit (119) to obtain a control signal Com;
step 11: the control signal Com passes through a PWM generating unit (120) to obtain a PWM control signal;
step 12: the PWM control signal drives a BUCK1 conversion circuit switching tube Q1 and a BUCK2 conversion circuit switching tube BUCK switching tube Q2.
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