CN102843060B - Two-level two-direction current transformer and control method thereof - Google Patents

Two-level two-direction current transformer and control method thereof Download PDF

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Publication number
CN102843060B
CN102843060B CN201210334342.8A CN201210334342A CN102843060B CN 102843060 B CN102843060 B CN 102843060B CN 201210334342 A CN201210334342 A CN 201210334342A CN 102843060 B CN102843060 B CN 102843060B
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China
Prior art keywords
converter
voltage
current
contactor
control board
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Expired - Fee Related
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CN201210334342.8A
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CN102843060A (en
Inventor
徐进
孙善勤
刘婉丽
刘伟
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China Shipbuilding Corp (nanjing) Amperex Technology Ltd
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China Shipbuilding Corp (nanjing) Amperex Technology Ltd
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    • YGENERAL 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
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E40/00Technologies for an efficient electrical power generation, transmission or distribution
    • Y02E40/30Reactive power compensation
    • YGENERAL 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
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E40/00Technologies for an efficient electrical power generation, transmission or distribution
    • Y02E40/40Arrangements for reducing harmonics

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  • Dc-Dc Converters (AREA)

Abstract

The invention discloses a two-level two direction current transformer and a control method of the two-level two direction current transformer. The inverter comprises a direct-current (DC) breaker, a DC filter, a DC/DC converter, a DC/alternating-current (AC) converter, an AC filter, an AC contactor I, an AC contactor II, an isolation transformer, an AC breaker, a DC/DC pulse-width modulation (PWM) drive circuit, a DC/AC PWM drive circuit, a control panel and a human-computer interface. The current transformer is simple in structure and low in cost. In the control method, the DC/AC converter and the DC/DC converter are controlled independently, so that the whole current transformer is of a modular structure without mutual interferences, distribution of electric energies is managed preferably, and fault diagnosis and inspection for a system are convenient.

Description

A kind of two-level two-direction current transformer and control method thereof
Technical field
The present invention relates to a kind of two-level two-direction current transformer and control method thereof, belong to T & D Technology field.
Background technology
Along with some are non-linear and time variation electronic installation etc. is applied on a large scale, make electric current in electrical network contain a large amount of harmonic waves and idle component, cause current waveform Severe distortion, bring harm to the production of electric energy and transmission, also affect the use of electronic equipment.
All there is the excessive or too small problem of charging current at charging initial stage and later stage in storage battery, if current ripples is excessive, can produce harm to some current ripples responsive type storage battery.When battery discharging, current transformer is operated in discharge mode, and in circuit, the discharge and recharge effect of inductance must cause the generation of storage battery output current ripple.Current two way convertor also exists the very flexible of system and the shortcoming of configurability difference, realize harmonics restraint and reactive power compensation, traditional method all can give system configuration harmonics restraint and reactive power compensator specially, and this adds system cost undoubtedly, and accessible site degree is not high.
Summary of the invention
The technical problem that the present invention solves is to provide a kind of without the need to increasing extra harmonics restraint and reactive power compensator device can realize filtering harmonic wave, dynamic compensating system is idle and voltage fluctuation, the two-level two-direction current transformer that suppresses resonance, improve power factor.
For solving the problems of the technologies described above, a kind of two-level two-direction current transformer of the present invention comprises DC circuit breaker, DC filter, DC/DC converter, DC/AC converter, alternating current filter, A.C. contactor I, A.C. contactor II, isolating transformer, AC circuit breaker, DC/DC PWM drive circuit, DC/AC PWM drive circuit, control board and man-machine interface;
Wherein, the input of described DC filter is connected with batteries via DC circuit breaker; The described low-pressure end of DC/DC converter is connected with the output of DC filter, and high-pressure side is connected with the low-pressure end of DC/AC converter; The input of described alternating current filter is connected with the high-pressure side of DC/AC converter, and output is connected with A.C. contactor II with A.C. contactor I parallel with one another respectively;
The low-pressure end of described isolating transformer is connected with the output of A.C. contactor I, A.C. contactor II respectively, after high-pressure side is connected with AC circuit breaker, is connected with electrical network via ac bus;
Described control board comprises DC/DC control board and DC/AC control board, and DC/DC control board is connected with DC/DC PWM drive circuit; DC/AC control board is connected with DC/AC PWM drive circuit; This control board is connected with man-machine interface by CAN.
Meanwhile, for realizing DC-to-DC, DC-AC Two Stages, manage the distribution of electric energy largely, the present invention also provides a kind of control method of two-level two-direction current transformer, comprises following methods:
Step one, start two-level two-direction current transformer, arrange basic parameter by man-machine interface, described basic parameter comprises the charging and discharging currents maximum permissible value of storage battery, the bound of charging/discharging voltage, communication modes and filtering mode;
The mode of operation of step 2, selection two way convertor, described mode of operation comprises battery charging pattern and batteries discharge mode; Systematic sampling, carries out passage self-inspection, if fault-free, then first closes A.C. contactor II, then judges whether line voltage connects normally, if connect normal, and closed A.C. contactor I;
The pwm pulse modulation program of step 3, startup DC/AC converter, the DC bus side voltage of real-time detection DC/AC converter, judge whether the DC bus side voltage of DC/AC converter is more than or equal to 620V, judge whether batteries terminal voltage is more than or equal to 25V simultaneously, if, then DC circuit breaker closes, and starts the pwm pulse modulation program of DC/DC converter, realizes batteries and carry out charge or discharge; If not then DC circuit breaker is in off-state;
Step 4, the electric current detecting in real time batteries and voltage, when batteries is full of or namely discharge off reaches discharge and recharge upper lower limit value, two way convertor power cut-off.
The present invention compared with prior art has following significant advantage: 1) the present invention is provided with user-machine interface, can set mode of operation and running parameter flexibly, makes charge and discharge process simulate best charging and discharging curve preferably; Can realize monitoring in real time the running status of current transformer in man-machine interface simultaneously, get information about very much the running status of current transformer; 2) control of DC/AC converter of the present invention adopts harmonic detecting module, can detect harmonic current and reactive current, has filtering and the adjustable function of power factor; 3) independence that the present invention realizes Two Stages and DC/AC converter and DC/DC converter controls, and whole device realizes modular construction, does not interfere with each other, for the failure diagnosis of system and inspection provide conveniently.
Below in conjunction with the drawings and specific embodiments, the present invention is described in further detail;
Accompanying drawing explanation
Fig. 1 is the structured flowchart of two-level two-direction current transformer of the present invention;
Fig. 2 is the control block diagram of DC/AC converter in the present invention;
Fig. 3 is the control block diagram of DC/DC converter in the present invention;
Fig. 4 is two-level two-direction current transformer control method flow chart of the present invention;
Embodiment
As shown in Figure 1, a kind of two-level two-direction current transformer of the present invention, comprises DC circuit breaker 1, DC filter 2, DC/DC converter 3, DC/AC converter 4, alternating current filter 5, A.C. contactor I 6, A.C. contactor II 7, isolating transformer 8, AC circuit breaker 9, DC/DC PWM drive circuit 12, DC/AC PWM drive circuit 13, control board 10 and man-machine interface 11;
Wherein, the input of described DC filter is connected with batteries via DC circuit breaker; The described low-pressure end of DC/DC converter is connected with the output of DC filter, and high-pressure side is connected with the low-pressure end of DC/AC converter; The input of described alternating current filter is connected with the high-pressure side of DC/AC converter, and output is connected with A.C. contactor II with A.C. contactor I parallel with one another respectively;
The low-pressure end of described isolating transformer is connected with the output of A.C. contactor I, A.C. contactor II respectively, after high-pressure side is connected with AC circuit breaker, is connected with electrical network via ac bus;
Described control board comprises DC/DC control board and DC/AC control board, and DC/DC control board is connected with DC/DC PWM drive circuit; DC/AC control board is connected with DC/AC PWM drive circuit; This control board is connected with man-machine interface by CAN.
Wherein, DC/DC converter is formed in parallel by three Buck conversion circuits (buck), and DC/AC converter takes parallel connection type APF topological structure to connect, and is a three phase full bridge circuit, carries out inversion or rectification work.
DC/DC control board 101 adopts 32 of TI company TMS320F2812DSP and 32 the floating-point high speed numerical processor TMS320F28335 that fix a point respectively with the master controller of DC/AC control board 102, carry out independent control, do not interfere with each other, its maximum operating frequency is 150MHZ, and processing speed is fast.
Described man-machine interface is provided with liquid crystal display, control button, indicator light and operation monitoring display; Described control button comprises reset, cancellation, menu and arranges button, and described indicator light comprises power lights, runs display lamp, transmission, accepting state lamp and malfunction coefficient lamp; By operation monitoring display, monitoring display is carried out to the output voltage electric current of batteries and DC bus-bar voltage electric current.
This current transformer is provided with protective circuit manually, and mandatory cut-out main circuit, makes current transformer be in off-mode.
This current transformer is provided with fault detect and warning display, voltage and current signal during closure state and current transformer operating state to the state of the temperature of IGBT fin, PWM drive plate, alternating current-direct current circuit breaker and A.C. contactor detects, if there is fault, then buzzer warning display, and fault data recorder is carried out in man-machine interface.
As shown in Figure 4, a kind of control method of two-level two-direction current transformer, comprises the following steps:
Step one, start two-level two-direction current transformer, arrange basic parameter by man-machine interface, described basic parameter comprises the charging and discharging currents maximum permissible value of storage battery, the bound of charging/discharging voltage, communication modes and filtering mode;
The mode of operation of step 2, selection two way convertor, described mode of operation comprises battery charging pattern and batteries discharge mode; Systematic sampling, carries out passage self-inspection, if fault-free, then first closes A.C. contactor II, then judges whether line voltage connects normally, if connect normal, and closed A.C. contactor I;
The pwm pulse modulation program of step 3, startup DC/AC converter, the DC bus side voltage of real-time detection DC/AC converter, judge whether the DC bus side voltage of DC/AC converter is more than or equal to 620V, judge whether batteries terminal voltage is more than or equal to 25V simultaneously, if, then DC circuit breaker closes, and starts the pwm pulse modulation program of DC/DC converter, realizes batteries and carry out charge or discharge; If not then DC circuit breaker is in off-state;
Wherein, DC/AC converter and DC/DC converter independently control, and as shown in Figure 2, the pwm pulse modulated process of DC/AC converter is specific as follows:
Steps A: the DC voltage of DC/AC converter is sampled, obtains feedback signal U cd;
Step B: by voltage given signal with DC voltage feedback signal U cddifference send into pi regulator 14 and carry out PI adjustment and amplitude limit 15, as the input of harmonic detecting module 16, to ensure the stable of DC voltage;
The AC three-phase current signal i of step C: foreign current transducer CT collection DC/AC converter a, i b, i cdeliver to harmonic detecting module, this module extracts harmonic current by utilizing ip-iq method the harmonic compensation current i provided is needed as the given of hysteresis regulator and DC/AC converter ca, i cb, i cccompare, the difference obtained, respectively by hysteresis regulator 117, hysteresis regulator 2 18, hysteresis regulator 3 19, exports the modulation signal producing circuit 20 as SPWM, and then the pulse of control DC/AC converter exports.
As shown in Figure 3, the pwm pulse modulated process of described DC/DC converter is specific as follows:
Step a, the DC low-voltage side voltage of DC/DC converter, electric current to be sampled, obtain feedback voltage, current signal U d, i d;
Step b, by voltage given signal with DC voltage feedback signal U ddifference after subtracting each other is as the input of PID adjuster 1; By given value of current signal with DC side electricity current feedback signal i ddifference after subtracting each other is as the input of PID adjuster 2, respectively amplitude limit is carried out to the output of PID adjuster 1 and PID adjuster 2, value after amplitude limit produces circuit by EPWM again and produces the input of pwm signal as DC/DC PWM drive circuit, exports through the level conversion of DC//DC PWM drive circuit and then the pulse of control DC/DC converter;
Step 4, the electric current detecting in real time batteries and voltage, when batteries is full of or namely discharge off reaches discharge and recharge upper lower limit value, two way convertor power cut-off.
In whole control procedure, carry out the every protection of system in real time and detect, if there is fault, then carry out event of failure record, buzzer warning malfunction indicator lamp display simultaneously, produce protection off signal immediately, block pwm pulse and export, shutdown protection; Or can hand off main circuit artificially, shutdown is protected.

Claims (2)

1. a control method for two-level two-direction current transformer, described two-level two-direction current transformer comprises DC circuit breaker, DC filter, DC/DC converter, DC/AC converter, alternating current filter, A.C. contactor I, A.C. contactor II, isolating transformer, AC circuit breaker, DC/DC PWM drive circuit, DC/AC PWM drive circuit, control board and man-machine interface; Wherein, the input of described DC filter is connected with batteries via DC circuit breaker; The described low-pressure end of DC/DC converter is connected with the output of DC filter, and high-pressure side is connected with the low-pressure end of DC/AC converter; The input of described alternating current filter is connected with the high-pressure side of DC/AC converter, and output is connected with A.C. contactor II with A.C. contactor I parallel with one another respectively;
The low-pressure end of described isolating transformer is connected with the output of A.C. contactor I, A.C. contactor II respectively, after high-pressure side is connected with AC circuit breaker, is connected with electrical network via ac bus;
Described control board comprises DC/DC control board and DC/AC control board, and DC/DC control board is connected with DC/DCPWM drive circuit; DC/AC control board is connected with DC/AC PWM drive circuit; This control board is connected with man-machine interface by CAN, it is characterized in that, comprises the following steps:
Step one, start two-level two-direction current transformer, arrange basic parameter by man-machine interface, described basic parameter comprises the charging and discharging currents maximum permissible value of storage battery, the bound of charging/discharging voltage, communication modes and filtering mode;
The mode of operation of step 2, selection two way convertor, described mode of operation comprises battery charging pattern and batteries discharge mode; Systematic sampling, carries out passage self-inspection, if fault-free, then first closes A.C. contactor II, then judges whether line voltage connects normally, if connect normal, and closed A.C. contactor I;
The pwm pulse modulation program of step 3, startup DC/AC converter, the DC bus side voltage of real-time detection DC/AC converter, judge whether the DC bus side voltage of DC/AC converter is more than or equal to 620V, judge whether batteries terminal voltage is more than or equal to 25V simultaneously, if, then DC circuit breaker closes, and starts the pwm pulse modulation program of DC/DC converter, realizes batteries and carry out charge or discharge; If not then DC circuit breaker is in off-state;
Step 4, the electric current detecting in real time batteries and voltage, when batteries is full of or namely discharge off reaches discharge and recharge upper lower limit value, two way convertor power cut-off.
2. the control method of two-level two-direction current transformer according to claim 1, it is characterized in that: in described step 3, DC/AC converter and DC/DC converter independently control, and wherein, the pwm pulse modulated process of DC/AC converter is specific as follows:
Steps A: the DC voltage of DC/AC converter is sampled, obtains feedback signal U cd;
Step B: by voltage given signal with DC voltage feedback signal U cddifference carry out PI adjustment and amplitude limit, as the input of harmonic detecting module, to ensure the stable of DC voltage;
The AC three-phase current signal i of step C: foreign current transducer CT collection DC/AC converter a, i b, i cdeliver to harmonic detecting module, this module extracts harmonic current by utilizing ip-iq method the harmonic compensation current i provided is needed as the given of hysteresis regulator and DC/AC converter ca, i cb, i cccompare, the difference obtained, respectively by hysteresis regulator 1, hysteresis regulator 2, hysteresis regulator 3, exports the drive singal producing circuit as SPWM, and then the pulse of control DC/AC converter exports;
The pwm pulse modulated process of described DC/DC converter is specific as follows:
Step a, the DC low-voltage side voltage of DC/DC converter, electric current to be sampled, obtain feedback voltage, current signal U d, i d;
Step b, by voltage given signal with DC voltage feedback signal U ddifference after subtracting each other is as the input of PID adjuster 1; By given value of current signal with DC side electricity current feedback signal i ddifference after subtracting each other is as the input of PID adjuster 2, respectively amplitude limit is carried out to the output of PID adjuster 1 and PID adjuster 2, value after amplitude limit produces circuit by EPWM again and produces the input of pwm signal as DC/DC PWM drive circuit, exports through the level conversion of DC/DC PWM drive circuit and then the pulse of control DC/DC converter.
CN201210334342.8A 2012-09-11 2012-09-11 Two-level two-direction current transformer and control method thereof Expired - Fee Related CN102843060B (en)

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CN108964176A (en) * 2014-12-09 2018-12-07 许继电气股份有限公司 A kind of grid-connected electric discharge device of storage battery activation
CN105811547B (en) * 2016-03-24 2021-02-05 上海先拓电子有限公司 High-power high-voltage direct-current charging device
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CN106772105B (en) * 2017-02-28 2019-10-11 大连奇辉计算机网络有限公司 A kind of detecting device for storage battery of PWM control timing discharging
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CN109494776A (en) * 2018-11-30 2019-03-19 北京科诺伟业科技股份有限公司 The grid-connected bidirectional converter of energy-storage system and off-network double mode operation method
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