CN107346888B - Voltage source type adjusting device and self-checking method thereof - Google Patents
Voltage source type adjusting device and self-checking method thereof Download PDFInfo
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- CN107346888B CN107346888B CN201710443633.3A CN201710443633A CN107346888B CN 107346888 B CN107346888 B CN 107346888B CN 201710443633 A CN201710443633 A CN 201710443633A CN 107346888 B CN107346888 B CN 107346888B
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- power conversion
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- 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
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/12—Circuit arrangements for ac mains or ac distribution networks for adjusting voltage in ac networks by changing a characteristic of the network load
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- 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
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/28—Arrangements for balancing of the load in a network by storage of energy
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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
- H02M1/00—Details of apparatus for conversion
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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
- H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
- H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
- H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
- H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M7/53—Conversion of dc power input into ac power output without possibility of reversal 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
- H02M7/537—Conversion of dc power input into ac power output without possibility of reversal 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, e.g. single switched pulse inverters
- H02M7/5387—Conversion of dc power input into ac power output without possibility of reversal 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, e.g. single switched pulse inverters in a bridge configuration
-
- 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
- H02M1/00—Details of apparatus for conversion
- H02M1/0003—Details of control, feedback or regulation circuits
- H02M1/0009—Devices or circuits for detecting current in a converter
Abstract
The invention discloses a voltage source type adjusting device which comprises an energy supplementing unit, an energy storage unit, a power conversion unit, a filtering isolation unit, a solid-state switch unit, a circuit breaker, a current sampling unit and a control unit, wherein the power conversion unit is composed of a power semiconductor device and is used for converting direct current into alternating current; the direct current end of the power conversion unit is connected with the output side of the energy storage unit, and the alternating current end of the power conversion unit is connected with the primary side of the filtering isolation unit; the secondary side of the filtering isolation unit is connected with the solid-state switch unit; the input side of the energy supplementing unit is connected with the power supply side, and the output side of the energy supplementing unit is connected with the input side of the energy storage unit; the current sampling unit is used for collecting alternating current output by the power conversion unit and sending a signal to the control unit, and the control unit is used for controlling the on-off of a power semiconductor device in the power conversion unit. The device can realize a self-checking function with high reliability. The invention also discloses a self-checking method of the voltage source type adjusting device.
Description
Technical Field
The present invention relates to power electronic converters, and more particularly, to a voltage regulator and a self-checking method thereof.
Background
The voltage regulating device is connected in series between a power supply and a load, and is in a bypass standby state in normal time, when the power supply voltage is abnormal, the voltage regulating device can be immediately put into operation to output compensation voltage and maintain the load voltage in a normal range. The patent CN103457283B introduces a typical composition and operation principle of the device, the voltage regulating device bypasses through the solid-state switch for a long time and only works when the voltage of the power grid is abnormal, therefore, the power conversion unit is in a standby state for a long time, because the power conversion unit includes the power semiconductor device, the device does not work for a long time and cannot determine whether the device is damaged, when the supplementary unit needs to work, if the device is damaged, the device cannot realize a compensation function, thereby causing an important load to lose power, and it is necessary to perform self-check on the device.
Disclosure of Invention
The invention aims to provide a voltage source type adjusting device and a self-checking method thereof, which can realize a high-reliability self-checking function.
In order to achieve the above purpose, the solution of the invention is:
a voltage source type adjusting device comprises an energy supplementing unit, an energy storage unit, a power conversion unit, a filtering isolation unit, a solid-state switch unit, a circuit breaker, a current sampling unit and a control unit, wherein the power conversion unit is composed of a power semiconductor device and is used for converting direct current into alternating current; the direct current end of the power conversion unit is connected with the output side of the energy storage unit, and the alternating current end of the power conversion unit is connected with the primary side of the filtering isolation unit; the secondary side of the filtering isolation unit is connected with the solid-state switch unit; the input side of the energy supplementing unit is connected with the power supply side, and the output side of the energy supplementing unit is connected with the input side of the energy storage unit; the current sampling unit is used for collecting alternating current output by the power conversion unit and sending a signal to the control unit, and the control unit is used for controlling the on-off of a power semiconductor device in the power conversion unit.
The power conversion unit is composed of four groups of power semiconductor devices with anti-parallel diodes, wherein a first power semiconductor device and a second power semiconductor device are connected in series in the same direction to form a first bridge arm, a third power semiconductor device and a fourth power semiconductor device are connected in series in the same direction to form a second bridge arm, and the first bridge arm and the second bridge arm are connected in parallel in the same direction; the source electrodes of the first power semiconductor device and the third power semiconductor device are defined as direct current positive ends, the drain electrodes of the second power semiconductor device and the fourth power semiconductor device are defined as direct current negative ends, and the middle point of the first bridge arm and the middle point of the second bridge arm are defined as alternating current ends.
The power semiconductor device in the power conversion unit is an IGBT.
The filtering isolation unit comprises a resistor, a capacitor and an isolation transformer, wherein the resistor and the capacitor form a resistance-capacitance series connection, the primary side of the isolation transformer is connected with the alternating current end of the power conversion unit, and the secondary side of the isolation transformer is connected with the resistance-capacitance series connection in parallel.
The filtering isolation unit comprises a resistor, a capacitor and an inductor, wherein the resistor and the capacitor form a resistor-capacitor series connection, one end of the inductor is connected with one alternating current end of the power conversion unit, the other end of the inductor is connected with one end of the resistor-capacitor series connection, and the other end of the resistor-capacitor series connection is connected with the other alternating current end of the power conversion unit.
The solid-state switch unit comprises a fifth power semiconductor device, a sixth power semiconductor device, a first diode and a second diode, wherein the fifth power semiconductor device is reversely connected with the first diode in parallel, and the sixth power semiconductor device is reversely connected with the second diode in parallel; the two parallel branches are connected in series in reverse.
The solid-state switch unit comprises two groups of semi-controlled power semiconductor devices which are connected in reverse parallel.
A self-checking method of a voltage source type regulating device, when a solid-state switch unit is closed, the self-checking method is used for self-checking the regulating device, and comprises the following steps:
step 1, setting a self-checking current target value, wherein the self-checking current target value does not exceed the maximum current which can be endured by a power semiconductor device in a control power conversion unit;
step 3, the current sampling unit detects the output current of the alternating current side of the power conversion unit in real time and sends the output current to the control unit;
step 5, after adjustment, if the measured current can be controlled to be close to the target value of the self-checking current and kept stable, the self-checking is considered to be successful, a power semiconductor device in the power conversion unit is locked, and a next self-checking instruction is waited; after adjustment, if the measured current cannot be controlled to be close to the target value of the self-checking current, the self-checking is considered to be failed, the power semiconductor device in the power conversion unit is locked, a fault is sent to the power semiconductor device, and the circuit breaker is closed.
In the step 4, the control unit adopts closed-loop vector control or a hysteresis control mode to control the current stably.
The self-checking command is automatically sent in a circulating mode at a certain period, and the period range is 60 s-3600 s.
After the scheme is adopted, the power semiconductor device in the power conversion unit is periodically enabled to work by circularly issuing the self-checking command, whether the equipment is normal or not is judged by detecting the current, the method is simple and easy to implement, and the reliability of the device is greatly improved.
The invention has the following beneficial effects:
(1) the device and the method provided by the invention can realize the self-checking of the equipment only by adding little cost (the current sampling unit), can periodically enable the power semiconductor device in the power conversion unit to work by circularly issuing the self-checking command under the condition that the solid-state switch is closed, and judge whether the equipment is normal or not by detecting the current, and the method is simple and easy to realize, and greatly improves the reliability of the device.
(2) When the device is in self-checking, the power supply to the load is not influenced completely, after the self-checking fails, a fault is reported, the breaker is closed, and the equipment can be overhauled in the period.
(3) In the self-checking process, current flows through the energy supplementing unit, the energy storage unit, the power conversion unit and the filtering isolation unit, when any unit of the equipment breaks down, the detection can be effectively realized, and the equipment can be comprehensively and accurately detected.
Drawings
FIG. 1 is a circuit diagram of a first embodiment of the apparatus of the present invention;
FIG. 2 is a circuit diagram of a second embodiment of the apparatus of the present invention;
FIG. 3 is a circuit diagram of a first embodiment of a solid state switching cell in the apparatus of the present invention;
FIG. 4 is a circuit diagram of a second embodiment of a solid state switching cell in the apparatus of the present invention;
fig. 5 is a schematic diagram of a current loop during self-test according to the present invention.
Detailed Description
The technical solution and the advantages of the present invention will be described in detail with reference to the accompanying drawings.
As shown in fig. 1 and fig. 2, the present invention provides a voltage source type adjusting device, which includes an energy supplementing unit 5, an energy storage unit 1, a power conversion unit 2, a filtering isolation unit 3, a solid state switch unit 4, a circuit breaker 6, a current sampling unit 7, and a control unit 8, wherein the power conversion unit 2 is composed of a power semiconductor device, and can convert direct current into alternating current, a direct current end of the power conversion unit 2 is connected to an output side of the energy storage unit 1, and an alternating current end is connected to a primary side of the filtering isolation unit 3; the secondary side of the filtering isolation unit 3 is connected with the solid-state switch unit 4; the input side of the energy supplementing unit 5 is connected with the power supply side, and the output side is connected with the input side of the energy storage unit 1; the current sampling unit 7 can collect alternating current output by the power conversion unit 2 and send signals to the control unit 8, and the control unit 8 can control the on or off of a power semiconductor device in the power conversion unit 2.
As shown in fig. 1 and fig. 2, the power conversion unit 2 is composed of four groups of power semiconductor devices with anti-parallel diodes, wherein the first power semiconductor device S1 and the second power semiconductor device S2 are connected in series in the same direction to form a first bridge arm, the third power semiconductor device S3 and the fourth power semiconductor device S4 are connected in series in the same direction to form a second bridge arm, and the first bridge arm and the second bridge arm are connected in parallel in the same direction; the source electrodes of the first power semiconductor device and the third power semiconductor device are defined as direct current positive ends, the drain electrodes of the second power semiconductor device and the fourth power semiconductor device are defined as direct current negative ends, and the middle point of the first bridge arm and the middle point of the second bridge arm are defined as alternating current ends. In the present embodiment, the power semiconductor devices in the power conversion unit 2 are IGBTs, and 4 groups of IGBTs with anti-parallel diodes constitute a single-phase full-bridge converter as the power conversion unit.
As shown in fig. 1, the first implementation circuit diagram of the filtering isolation unit 3 in the present invention includes a resistor, a capacitor, and an isolation transformer, wherein the resistor and the capacitor form a resistor-capacitor series connection, the primary side of the isolation transformer is connected to the two ac terminals, respectively, and the secondary side of the isolation transformer is connected in parallel with the resistor-capacitor series connection. The first embodiment of the filtering isolation unit adopts an isolation transformer, a resistor and a capacitor to form a filtering isolation loop, wherein the leakage inductance of the isolation transformer can be used as a filter reactor of a filtering branch circuit, and the filtering isolation unit can play a role in isolating and boosting while playing a filtering effect.
As shown in fig. 2, a second implementation circuit diagram of the filtering isolation unit 3 in the present invention includes a resistor, a capacitor, and an inductor, wherein the resistor and the capacitor form a resistor-capacitor series connection, one end of the inductor is connected to an ac terminal, the other end of the inductor is connected to one end of the resistor-capacitor series connection, and the other end of the resistor-capacitor series connection is connected to the other ac terminal; the filtering and isolating unit adopts an LCR second-order filter structure which is common to power electronics.
As shown in fig. 3, the circuit diagram of a first embodiment of the solid-state switch unit 4 of the present invention includes fifth and sixth power semiconductor devices, and first and second diodes, wherein the fifth power semiconductor device is connected in inverse parallel with the first diode, and the sixth power semiconductor device is connected in inverse parallel with the second diode; the two parallel branches are connected in series in a reverse direction, and the fifth power semiconductor device and the sixth power semiconductor device have turn-on and turn-off capabilities and can be IGBTs.
Fig. 4 is a circuit diagram of a second embodiment of the solid-state switching unit 4 according to the present invention, which includes two sets of half-controlled power semiconductor devices connected in anti-parallel, and the half-controlled power semiconductor devices may specifically be thyristors.
Based on the above adjusting device, the present invention further provides a self-checking method for the voltage source type adjusting device, which can perform self-checking on the adjusting device when the solid-state switch unit is closed, and the method includes the following steps:
step 1, setting a self-checking current target value, wherein the self-checking current target value does not exceed the maximum current which can be endured by a power semiconductor device in a control power conversion unit;
in the present embodiment, the power semiconductor device withstand current is 1000A, and the self-test current target value may be set to 200A.
after the power semiconductor devices in the power conversion unit start to operate, a small on duty ratio should be set to prevent overcurrent, and the duty ratio should be gradually adjusted to be high.
Step 3, the current sampling unit detects the output current of the alternating current side of the power conversion unit in real time and sends the output current to the control unit;
the current control can be stabilized by adopting closed-loop vector control or hysteresis control.
And 5, after adjustment, if the measured current can be controlled to be close to the target value of the self-checking current and be kept stable, considering that the self-checking is successful, locking the power semiconductor device in the power conversion unit and waiting for the next self-checking instruction.
And 6, after adjustment, if the measured current cannot be controlled to be close to the target value of the self-checking current, considering that self-checking fails, locking a power semiconductor device in the power conversion unit, uploading a fault, and closing the circuit breaker.
The self-checking command can be automatically sent in a circulating mode at a certain period, and the period range is 60 s-3600 s. In this example, a cycle period of 600s, i.e., 10 minutes, was selected for one self-test.
Fig. 5 is a schematic diagram of a current flowing through a loop during self-test, when a power semiconductor device works, 4 IGBTs are turned on in turn at the moment, and an alternating current voltage can be output by a pulse width modulation technology, because the solid-state switching unit is in a closed state, the loop is equivalent to an alternating current voltage source flowing through the solid-state switching unit after passing through an inductor, because the inductor only plays an impedance role on an alternating current signal and the inductance value is usually small, the output voltage is a voltage signal with a small amplitude, the voltage is applied to the inductor to obtain the current, and the current amplitude can be controlled. The current reflects the state of the whole loop, and only if the equipment on the loop is normal, the current can be controlled at a stable set value, and because when the IGBT works, the equipment can generate larger loss, the energy storage unit can consume energy, the energy supplementing unit is required to continuously supplement energy for the energy storage unit, and meanwhile, whether the energy storage unit and the energy supplementing unit can work normally or not is also verified.
The self-checking method utilizes the original equipment, only one current sampling unit is added, the comprehensive self-checking process is realized, and meanwhile, the normal operation of the equipment is not influenced.
The above embodiments are only for illustrating the technical idea of the present invention, and the protection scope of the present invention is not limited thereby, and any modifications made on the basis of the technical scheme according to the technical idea of the present invention fall within the protection scope of the present invention.
Claims (3)
1. A self-checking method of a voltage source type adjusting device comprises an energy supplementing unit, an energy storage unit, a power conversion unit, a filtering isolation unit, a solid-state switch unit, a circuit breaker, a current sampling unit and a control unit, wherein the power conversion unit is composed of power semiconductor devices and is used for converting direct current into alternating current; the direct current end of the power conversion unit is connected with the output side of the energy storage unit, and the alternating current end of the power conversion unit is connected with the primary side of the filtering isolation unit; the secondary side of the filtering isolation unit is connected with the solid-state switch unit in parallel; the circuit breaker is connected with the secondary side of the filtering isolation unit in parallel; the two ends of the secondary side of the filtering isolation unit are respectively connected with the power supply side and the load side; the input side of the energy supplementing unit is connected with the power supply side, and the output side of the energy supplementing unit is connected with the input side of the energy storage unit; the current sampling unit is used for collecting alternating current output by the power conversion unit and sending a signal to the control unit, and the control unit is used for controlling the power semiconductor device in the power conversion unit to be switched on or switched off;
when the solid-state switch unit is closed, the self-checking method is characterized by comprising the following steps:
step 1, setting a self-checking current target value, wherein the self-checking current target value does not exceed the maximum current which can be endured by a power semiconductor device in a control power conversion unit;
step 2, after receiving the self-checking command, the power semiconductor device in the power conversion unit starts to work;
step 3, the current sampling unit detects the output current of the alternating current side of the power conversion unit in real time and sends the output current to the control unit;
step 4, when the actually measured current received by the control unit deviates from the target value of the self-checking current, the control unit adjusts the on-off duty ratio of the power semiconductor device;
step 5, after adjustment, if the measured current can be controlled to be close to the target value of the self-checking current and kept stable, the self-checking is considered to be successful, a power semiconductor device in the power conversion unit is locked, and a next self-checking instruction is waited; after adjustment, if the measured current cannot be controlled to be close to the target value of the self-checking current, the self-checking is considered to be failed, the power semiconductor device in the power conversion unit is locked, a fault is sent to the power semiconductor device, and the circuit breaker is closed.
2. The self-test method of a voltage source type regulator as claimed in claim 1, wherein: in the step 4, the control unit adopts closed-loop vector control or a hysteresis control mode to control the current stably.
3. The self-test method of a voltage source type regulator as claimed in claim 1, wherein: the self-checking command is automatically sent in a circulating mode at a certain period, and the period range is 60 s-3600 s.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201710443633.3A CN107346888B (en) | 2017-06-13 | 2017-06-13 | Voltage source type adjusting device and self-checking method thereof |
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| CN201710443633.3A CN107346888B (en) | 2017-06-13 | 2017-06-13 | Voltage source type adjusting device and self-checking method thereof |
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| CN107346888B true CN107346888B (en) | 2021-02-09 |
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| CN114094839B (en) * | 2022-01-11 | 2022-04-08 | 四川大学 | Inductive energy storage type isolated DC-DC converter and control method thereof |
| CN114172381B (en) * | 2022-02-11 | 2022-04-15 | 四川大学 | Capacitive energy storage type isolation DC-DC converter and control method thereof |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN101345419B (en) * | 2008-05-14 | 2011-06-01 | 西安交通大学 | Series voltage quality regulator and fast investment and cutting method |
| CN103457283B (en) * | 2013-09-17 | 2016-01-20 | 无锡力豪科技有限公司 | A kind of super capacitor dynamic voltage recovery system and power-supply system |
| CN203589727U (en) * | 2013-12-05 | 2014-05-07 | 国家电网公司 | Large capacity unified power quality controller |
| JP6668128B2 (en) * | 2015-05-18 | 2020-03-18 | 株式会社キューヘン | Reactive power compensator |
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