CN102508072B - High-power three-level frequency converter temperature rise and loss testing method employing active front end - Google Patents
High-power three-level frequency converter temperature rise and loss testing method employing active front end Download PDFInfo
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- CN102508072B CN102508072B CN201110343361.2A CN201110343361A CN102508072B CN 102508072 B CN102508072 B CN 102508072B CN 201110343361 A CN201110343361 A CN 201110343361A CN 102508072 B CN102508072 B CN 102508072B
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Abstract
The invention relates to a high-power three-level converter temperature rise and loss testing method employing an active front end. The method is characterized by comprising the following steps of: (1) connecting a low-capacity reactor between a rectifying unit and an inverter unit of a frequency converter, and connecting a low-capacity direct-current power supply to a middle direct-current side of the frequency converter, and (2) setting the rectifying unit to operate in an inverter manner, setting an output voltage reference value of the rectifying unit and the output voltage reference value of the inverter unit at fixed values, adjusting the current which flows through the reactor, and simulating different work conditions and comprehensively testing the loss and temperature rise of the frequency converter under different work conditions by adjusting the magnitude of the output power and the power factor of the inverter unit so as to accurately estimate the output of the device. According to the invention, high-powder three-level frequency converter temperature rise and loss testing functions can be achieved by only one low-capacity reactor and one external low-capacity direct-current power supply. The method has the advantages of simple structure, accurate result, fewer used auxiliary apparatuses, easy realization and the like.
Description
Technical field
The invention belongs to frequency converter field, especially a kind of high-power three-level frequency converter temperature rise and loss test method that adopts Active Front End.
Background technology
Variable-frequency control technique has become a kind of important means that technological process was saved energy and reduce the cost, improved to industrial circle, improve the quality of products and improve environment, Promote Technology, in recent years, along with continuing to bring out of device for high-power power electronic, variable-frequency control technique is more and more towards high-voltage large-capacity trend development, all kinds of MW level frequency converters have been widely used in large scale industry production equipment, and its capacity is also improving constantly.
One of developing direction of big-power transducer is to adopt three level topologys, compare with two traditional level converters, three level structures have lot of advantages, such as: reduced the busbar voltage that each power device bears, therefore available low withstand voltage device is realized high-power output; The increase of level number has improved output voltage waveforms, has reduced harmonic distortion; Available lower switching frequency obtains voltage waveform relatively preferably, so switching loss is little, efficiency is high; Output voltage rate of change is lower, has improved the Electro Magnetic Compatibility of device etc.At present, the Foreign High Power frequency converter three level structures that adopt more; Dan China, owing to being subject to the effects limit such as line voltage grade, power electronic devices performance and technical merit, high-power tri-level variable frequency device technology is still immature, at aspects such as device design, manufacture and performance tests, still has many problems urgently to be resolved hurrily.
The test of big-power transducer equipment nominal output, because the restriction of be put to the test place capacity, place, power supply capacity etc. is difficult to carry out stable rated power test, is adopted to indirect method test conventionally.Therefore, effective, the energy-conservation test method of research big-power transducer is very necessary.The test method of having reported is mostly for power device or power cell, and these methods are difficult to frequency converter overall performance to make assessment conventionally, and need to take relatively high power from electrical network, has the problems such as test method is complicated, test findings is inaccurate.
Summary of the invention
The object of this invention is to provide and a kind ofly simply, accurately and only need take from electrical network high-power three-level frequency converter temperature rise and the loss test method of the employing Active Front End of less energy.
The present invention solves its technical matters and takes following technical scheme to realize:
The high-power three-level frequency converter temperature rise and the loss test method that adopt Active Front End, comprise the following steps:
(1) a low capacity reactor is connected between the rectification unit and inversion unit of frequency converter, a low capacity direct supply is connected on to frequency converter intermediate dc side, thereby rectification unit, intermediate dc side, inversion unit and reactor are formed to test loop;
(2) set rectification unit and move in inverter mode, the output voltage reference value of given rectification unit
with the output voltage reference value of inversion unit be
the output voltage reference value that keeps inversion unit
constant, the output voltage reference value of adjusting rectification unit
it is the electric current of the adjustable reactor of flowing through
by regulating size and the power factor of inversion unit output power, realize the simulation to different operating modes, loss and the temperature rise of full test frequency converter under different operating modes, and then accurate evaluation device is exerted oneself.
And, the electric current of the described reactor of flowing through
and inversion unit output power P
2be respectively:
And described frequency converter adopts Active Front End as rectification unit, its structure is two level or many level AC-DC-AC structure, and the device for power switching that frequency converter uses is IGBT or IGCT.
And described reactor capacity is less than 20% of frequency inverter capacity.
And described direct supply is taken from electrical network, its effect is that capacity is less than 5% of frequency inverter capacity for the active loss in test provides energy.
Advantage of the present invention and good effect are:
1, this test method is connected to reactor as load between rectification unit and inversion unit, make power pass through rectification unit, intermediate dc side, inversion unit and reactor and form loop, whole process of the test is except the loss on power device and circuit, there is no other meritorious consumptions, only need take less energy from electrical network and can make frequency converter flow through relatively high power, thereby realize the function of carrying out high-power frequency converter load testing at low capacity electrical network.
2, this test method is by regulating the voltage difference at reactor two ends to carry out regulating load electric current, guaranteeing under the prerequisite of current continuity, selectable reactor capacity is less, its capacity, volume are also all less, solve conventional test method and provide supporting with it motor and mechanical load in order to allow inversion unit export high-power needs, also will consider the problems such as motor is installed, coaxial connection.
3, this test method is except frequency converter to be tested, only needs a low capacity reactor and an external low capacity direct supply, and therefore, this test method auxiliary appliance used is few, connect simply, easily realize.
Accompanying drawing explanation
Fig. 1 is electrical wiring schematic diagram of the present invention;
Fig. 2 is that the present invention is at voltage, the electric current phasor figure of test process;
Fig. 3 is that the modulation of inversion unit output voltage involves the waveform schematic diagram of output current in one-period;
Fig. 4 is the circulation path schematic diagram of electric current on brachium pontis of inversion unit in one-period;
Fig. 5 is voltage, electric current and the active power simulation result schematic diagram of inversion unit side;
Fig. 6 is voltage, electric current and the active power simulation result schematic diagram of rectification unit.
Embodiment
Below in conjunction with accompanying drawing, the embodiment of the present invention is further described:
Adopt high-power three-level frequency converter temperature rise and the loss test method of Active Front End, for realizing high-power three-level frequency converter temperature rise and loss test function.Specifically comprise the following steps:
Step 1, by mode of connection shown in Fig. 1, a low capacity reactor is connected between the rectification unit and inversion unit of frequency converter, a low capacity direct supply is connected on to frequency converter intermediate dc side, thereby rectification unit, intermediate dc side, inversion unit and reactor are formed to test loop.
In this step, frequency converter is comprised of rectification unit, intermediate dc side and inversion unit, and the reactor capacity being connected between rectification unit and inversion unit is determined according to test demand, conventionally can accomplish to be less than 20% of frequency inverter capacity; The capacity of low capacity direct supply is less than 5% of frequency inverter capacity conventionally, it can be the structure that common three phase rectifier adds filter capacitor, this direct supply from electrical network power taking and for test in active loss energy is provided, due to test in except the loss of equipment and circuit, there is no other meritorious consumptions, the power of therefore taking from electrical network is less, also less to the impact of electrical network.
In this step,
the phasor form that represents rectification unit a phase voltage (being the voltage of the relative DC side mid point of a phase terminal O),
the output voltage of inversion unit.If the induction reactance of reactor is selected littlely,
with
only need less deviation just can make
have compared with amplitude, inversion unit can be moved under nominal output.In test process, its voltage, electric current phasor relation as shown in Figure 2, can be calculated the electric current of the reactor of flowing through by the phasor relation in Fig. 2
and inversion unit output power P
2:
During test, first according to the operating mode of expectation test, determine the voltage of inversion unit output
active-power P
2and the parameter such as power factor, then calculate the output voltage of rectification unit
will
be set as respectively the voltage given value of rectification unit, inversion unit, after device stable operation, can measure the temperature rise of each power device of frequency converter.If set inversion unit output power and power factor, be ratings, can measure temperature rise and the loss of power device under nominal output.In above-mentioned process of the test, the path of power stream is to export from inversion unit, the loop forming through reactor, rectification unit and intermediate dc side, whole process is except the loss on power device and circuit, there is no other meritorious consumptions, compare with the rated capacity of frequency converter to be measured, the loss of test is very little, conventionally less than 10%, therefore for these losses provide the external direct current power supply capacity of electric energy, also can do very littlely.
In process of the test, keep inversion unit output voltage constant, regulating the output voltage of rectification unit side is adjustable reactor current, because reactor induction reactance is selected littlely, its both end voltage does not need mutually far short of what is expectedly can produce larger electric current, makes inversion unit may operate at nominal output; The power factor of exporting by flexible inversion unit, realizes the simulation to different operating modes, loss and the temperature rise of full test frequency converter under different operating modes, and then accurate evaluation device is exerted oneself.
Although be noted that the mode of connection of Fig. 1 is for three level topology frequency converters, this method is also applicable to the big-power transducer test of two level or other structures, and the device for power switching of these frequency converters can be IGBT, can be also IGCT.
Key property of this method is that its inversion side power factor can flexible.Because the temperature rise of transducer power device is closely related with power factor, so power factor is adjustable very important to frequency converter device for testing temperature rise.For the impact of explanation power factor on device temperature rise, brief analysis is made in current flowing path when below Diode Clamping Three-Level Inverter is worked.Fig. 3 has provided the waveform of the interior inverter one phase voltage modulating wave u of one-period and this phase current i, in figure
for power-factor angle, illustrated case shows that now inverter connects inductive load.
1, region
Current path is as shown in Fig. 4 (a).Now modulation voltage is being for just, and load current is for negative, and this phase brachium pontis state of inversion unit is just, switch between zero; V1 and V3 conducting in turn, V2 is always in conducting state; Load current flows into by D1, D2 when positive status, when zero condition, by V3, D6, flows into.In said process, in V1, almost do not have electric current to flow through, loss is very little; The existing conduction loss of V3 also has switching loss; , there is conduction loss in sustained diode 1, D2 current flowing when conducting; D1 bears back-pressure when turn-offing, and has reverse recovery loss, and D2 when turn-offing due to V2 and V3 open-minded, do not bear back-pressure, there is no reverse recovery loss.
2, region
At the current path in this region as shown in Fig. 4 (b).Now modulation voltage is being for just, and load current is being for just, and this phase brachium pontis state of inversion unit is just, switch between zero; V1 and V3 conducting in turn, V2 is always in conducting state; Load current flows out by V1, V2 when positive status, when zero condition, by V2, D5, flows out.With region 1) analysis classes seemingly, now the existing conduction loss of V1 also has switching loss, there is conduction loss in V2; D5 bears back-pressure when turn-offing, and has reverse recovery loss.
3, region
Current path is as shown in Fig. 4 (c).Now modulation voltage is for negative, and load current is for just, and brachium pontis switches between negative state and zero condition; V2 and V4 conducting in turn, V3 is always in conducting state; Load current flows out by D3, D4 when negative state, when zero condition, by V2, D5, flows out.In this region, there is conduction loss and switching loss in V2 pipe; D3 pipe has conduction loss, and D4 manages existing conduction loss again reverse recovery loss.
4, region
Current path is as shown in Fig. 4 (d).Now modulation voltage is negative, and load current is for negative, and this phase brachium pontis state of inversion unit switches between negative, zero; V2 and V4 conducting in turn, V3 is always in conducting state; Load current flows into by V3, V4 when negative state, when zero condition, by V3, D6, flows into.In this region, V3, V4 be current flowing when conducting, has conduction loss; V4 is because switch motion also exists switching loss, and D6 exists reverse recovery loss.
Above-mentioned analysis shows: during tri-level inversion cell operation, in power device, the size of current flowing is relevant with power factor, the voltage magnitude of inversion unit output with the time, therefore the temperature rise of device is also relevant with power factor, therefore, adopt this test unit by regulating the power factor of inversion unit output, can loss and the temperature rise of comprehensive test frequency converter under various operating modes, and then accurate evaluation device is exerted oneself.
In order to verify feasibility of the present invention, below in conjunction with simulation example, the present invention will be further described.During emulation, frequency converter adopts three level structures, sets inverter and is output as:
p
2=2MW,
reactor is elected 1mH as, and line loss represents with the resistance that lumped parameter is 0.01 ' Ω; According to above-mentioned condition, the output voltage that can obtain PWM rectifier is:
inverter and PWM controlled rectifier are all adopted to space vector modulation, and PWM frequency is 625Hz, and simulation result during stable state as shown in Figure 5, Figure 6.Fig. 5 has provided voltage, electric current and the active power simulation result of inversion unit side, wherein, and u
2for the phase voltage waveform of inversion unit output, u
2ffor u
2fundamental waveform, i
lfor the electric current on reactor, p
2active power instantaneous value for inversion unit output; Fig. 6 has provided voltage, electric current and the active power simulation result of rectification unit, wherein, and u
1for the voltage waveform of the relative DC side mid point of rectification unit a O, i.e. rectification unit a phase voltage modulation waveform; u
1ffor u
1fundamental waveform; i
lfor a phase inductance current waveform; p
1for the instantaneous active power of rectification unit output, it is the result of calculating in each primitive period.As can be seen from Figure 5, the phase voltage first-harmonic u of inverter output
a1its peak value is 970V, and effective value is 686V, very approaching with set-point; The first-harmonic of phase voltage is ahead of phase current, according to the phase place of voltage over zero leading current zero crossing, infers, power factor is slightly larger than 0.85; The instantaneous value p of active power
2near 2MW, fluctuate.The result of Fig. 6 also approaches with emulation setting value, particularly instantaneous active power p
1near-1.98MW, fluctuate, the meritorious overwhelming majority that shows inverter output is rectified device and absorbs, and only has fraction to be converted into line loss, has realized the object of testing high-power device with low capacity electrical network.
It is emphasized that; embodiment of the present invention is illustrative; rather than determinate; therefore the present invention is not limited to the embodiment described in embodiment; every other embodiments that drawn by those skilled in the art's technical scheme according to the present invention, belong to the scope of protection of the invention equally.
Claims (5)
1. the high-power three-level frequency converter temperature rise and the loss test method that adopt Active Front End, is characterized in that: comprise the following steps:
(1) a low capacity reactor is connected between the rectification unit and inversion unit of frequency converter, a low capacity direct supply is connected on to frequency converter intermediate dc side, thereby rectification unit, intermediate dc side, inversion unit and reactor are formed to test loop;
(2) set rectification unit and move in inverter mode, the output voltage reference value of given rectification unit
with the output voltage reference value of inversion unit be
the output voltage reference value that keeps inversion unit
constant, the output voltage reference value of adjusting rectification unit
it is the electric current of the adjustable reactor of flowing through
by regulating size and the power factor of inversion unit output power, realize the simulation to different operating modes, loss and the temperature rise of full test frequency converter under different operating modes, and then accurate evaluation device is exerted oneself.
2. the high-power three-level frequency converter temperature rise of employing Active Front End according to claim 1 and loss test method, is characterized in that: the electric current of the described reactor of flowing through
and inversion unit output power P
2be respectively:
3. the high-power three-level frequency converter temperature rise of employing Active Front End according to claim 1 and loss test method, it is characterized in that: described frequency converter adopts Active Front End as rectification unit, its structure is two level or many level AC-DC-AC structure, and the device for power switching that frequency converter uses is IGBT or IGCT.
4. the high-power three-level frequency converter temperature rise of employing Active Front End according to claim 1 and loss test method, is characterized in that: described reactor capacity is less than 20% of frequency inverter capacity.
5. the high-power three-level frequency converter temperature rise of employing Active Front End according to claim 1 and loss test method, it is characterized in that: described direct supply is taken from electrical network, its effect is that capacity is less than 5% of frequency inverter capacity for the active loss in test provides energy.
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| CN103312188B (en) * | 2013-05-23 | 2015-08-26 | 西安交通大学 | For power supply and the method for testing thereof of reactor performance test in power electronic equipment |
| CN103312183B (en) * | 2013-05-23 | 2015-08-26 | 西安交通大学 | For power supply and the method for testing thereof of reactor performance test in phase control rectifier circuit |
| CN105093021B (en) * | 2015-08-11 | 2018-06-19 | 南方电网科学研究院有限责任公司 | Temperature rise test method of bridge arm reactor for modular multilevel converter |
| CN105425072A (en) * | 2015-11-30 | 2016-03-23 | 北京赛思亿电气科技有限公司 | Testing circuit and testing method for temperature rise of IGBT module of frequency converter |
| WO2018037499A1 (en) * | 2016-08-24 | 2018-03-01 | 東芝三菱電機産業システム株式会社 | Energization evaluation test device for input filter for pwm converter |
| CN108614168B (en) * | 2016-12-12 | 2020-07-07 | 北京天诚同创电气有限公司 | Full-power test method for power generation field converter |
| CN109283418A (en) * | 2018-11-28 | 2019-01-29 | 天津农学院 | A kind of factory power test test method of universal frequency converter |
| CN113092963A (en) * | 2021-04-07 | 2021-07-09 | 华北电力大学 | Bridge arm reactor alternating current-direct current superposition temperature rise test topology and device |
| CN115308515B (en) * | 2022-08-26 | 2024-02-20 | 天津电气科学研究院有限公司 | IGCT three-level power unit test system and method |
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Address after: 300180 Hedong District, Tianjin Jintang Road, No. 174 Patentee after: TIANJIN RESEARCH INSTITUTE OF ELECTRIC SCIENCE Co.,Ltd. Patentee after: TIANJIN TIANCHUAN ELECTRICAL Co.,Ltd. Address before: 300180 Hedong District, Tianjin Jintang Road, No. 174 Patentee before: TIANJIN DESIGN & RESEARCH INSTITUTE OF ELECTRIC DRIVE Co.,Ltd. Patentee before: TIANJIN TIANCHUAN ELECTRICAL Co.,Ltd. Address after: 300180 Hedong District, Tianjin Jintang Road, No. 174 Patentee after: TIANJIN DESIGN & RESEARCH INSTITUTE OF ELECTRIC DRIVE Co.,Ltd. Patentee after: TIANJIN TIANCHUAN ELECTRICAL Co.,Ltd. Address before: 300180 Hedong District, Tianjin Jintang Road, No. 174 Patentee before: Tianjin Design and Research Institute of Electric Drive Patentee before: TIANJIN TIANCHUAN ELECTRICAL Co.,Ltd. |