CN111965468B - Current control method of cascade submodule working condition simulation system suitable for NLC - Google Patents

Current control method of cascade submodule working condition simulation system suitable for NLC Download PDF

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CN111965468B
CN111965468B CN202010942352.4A CN202010942352A CN111965468B CN 111965468 B CN111965468 B CN 111965468B CN 202010942352 A CN202010942352 A CN 202010942352A CN 111965468 B CN111965468 B CN 111965468B
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CN111965468A (en
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马柯
李恩溢
蔡旭
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Shanghai Jiaotong University
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    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G—PHYSICS
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    • G05B11/36—Automatic controllers electric with provision for obtaining particular characteristics, e.g. proportional, integral, differential
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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
    • H02M5/00—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases
    • H02M5/40—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc
    • H02M5/42—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc by static converters
    • H02M5/44—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc by static converters using discharge tubes or semiconductor devices to convert the intermediate dc into ac
    • H02M5/453—Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases with intermediate conversion into dc by static converters using discharge tubes or semiconductor devices to convert the intermediate dc into ac using devices of a triode or transistor type requiring continuous application of a control signal
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
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    • H02M1/00—Details of apparatus for conversion
    • H02M1/0067—Converter structures employing plural converter units, other than for parallel operation of the units on a single load
    • H02M1/007—Plural converter units in cascade
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    • 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

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Abstract

The invention provides a current control method of a working condition simulation system of a cascaded converter submodule applicable to NLC, which is characterized in that the pulse voltage interference of a port of an object to be measured, which is caused by nearest level approximation modulation, is counteracted by compensating feedforward voltage in a current controller; a method for compensating the feed forward voltage, comprising: the method I comprises the steps of calculating the difference value of the number of the two sub-module groups to be tested which are put into the sub-modules, and multiplying the difference value by the capacitor voltage of a single sub-module, so that the feedforward voltage is generated. And secondly, sampling a voltage signal of the port of the object to be measured, performing low-pass filtering on the voltage signal, and taking the filtered voltage signal as a feedforward voltage. The current controller is compensated with the feedforward voltage, and current distortion caused by pulse voltage interference is avoided. Meanwhile, a working condition simulation system of the cascaded converter submodule and a submodule testing method are provided. The invention can better realize the working condition simulation of the cascaded converter submodule based on the nearest level approximation modulation.

Description

Current control method of cascade submodule working condition simulation system suitable for NLC
Technical Field
The invention relates to the technical field of power electronics, in particular to a current control method of a cascade submodule working condition simulation system suitable for NLC (nearest level approximation modulation), and a cascade submodule working condition simulation system and a test method realized based on the current control method.
Background
In recent years, the cascade converter is widely applied to medium-high voltage power transmission occasions by virtue of the characteristics of modularization, easiness in expansion and the like. With the continuous improvement of the capacity and the voltage grade of the cascaded converter, the evaluation and the detection of the reliability of the cascaded converter in the operation process are concerned more and more widely. In the early stage, in order to evaluate and detect the reliability of the cascaded converter, a complete cascaded converter system is often required to be built, but the reliability of the cascaded converter mainly depends on the reliability of a cascaded converter submodule, so that the reliability of the cascaded system is evaluated through a cascaded converter submodule working condition simulation test circuit, and the method becomes a more efficient and cost-saving method.
At present, the modulation method of the cascaded converter is mainly the nearest level approximation modulation method. Under the modulation method, the pulse voltage output by the submodule of the cascade converter has the characteristics of large pulse amplitude, wide pulse width and the like, and the submodule can be switched on or switched off for a long time, so that the pulse voltage of an object to be detected generates large interference on a current controller, and the current controller is difficult to control the current stably.
Through search, the following results are found:
the invention patent of china with patent number ZL201910083488.1 discloses a test circuit for multi-submodule multi-condition simulation of a cascade converter, which comprises: the current generator is used for generating test current and comprises a three-port converter and a corresponding filter; the sub-module system comprises an upper bridge arm test unit module and a lower bridge arm test unit module which are connected in series, wherein the upper bridge arm test unit module comprises a plurality of upper bridge arm test units which are connected in series, the lower bridge arm test unit module comprises a plurality of lower bridge arm test units which are connected in series, and each test unit comprises two tested sub-modules which are connected in series in an opposite direction. The upper bridge arm test unit and the lower bridge arm test unit receive the test current generated by the current generator and output voltage signals, or voltage signals and current signals of the tested sub-modules in each test unit to the outside. The method can realize the simulation of the operation condition of any submodule of the cascaded converter, and realizes the simultaneous test of a plurality of submodules under various conditions, thereby saving the test cost and improving the test efficiency, but still lacks an effective method to inhibit the voltage pulse interference caused by the recent level approximation modulation.
The Chinese invention patent with the patent number ZL201910083490.9 discloses a control method and a system for a cascade type converter multi-submodule multi-working-condition simulation device, wherein the simulation device comprises a current generator and a submodule system, the current generator is used for generating test current, the submodule system comprises an upper bridge arm test unit and a lower bridge arm test unit which are connected in series, the upper bridge arm test unit and the lower bridge arm test unit are used for receiving the current generated by the current generator and outputting capacitance voltage signals of the submodules; the cascade converter system parameter model is used for outputting current and voltage reference signals corresponding to the system parameters and the operation working conditions of the actual cascade converter to the current controller and the voltage controller; a current controller for generating a control signal for the current generator; and the voltage controller is used for generating control signals of the switching devices in the test units of the submodule system. The operation condition simulation of any submodule of the cascaded converter can be realized, the simultaneous test of a plurality of submodules under various working conditions is realized, the test cost is saved, the test efficiency and the test accuracy are improved, and the voltage pulse interference caused by the nearest level approximation modulation cannot be inhibited.
That is to say, in the conventional submodule working condition simulation test circuit of the cascaded converter, an effective method for suppressing voltage pulse interference caused by recent level approximation modulation is lacked. In order to eliminate the influence of the output pulse voltage of the sub-module, the field usually adds an additional auxiliary circuit, and controls the auxiliary circuit to operate in cooperation with the sub-module, so as to cancel the interference of the pulse voltage of the sub-module on the current controller. However, the additional control circuit increases the complexity of the control and the manufacturing cost of the analog test circuit, and the control delay caused by the dead zone of the switch will cause the synchronism of the auxiliary circuit and the pulse voltage to be reduced, so that the auxiliary circuit cannot well counteract the interference of the pulse voltage.
Therefore, a simpler and more cost-effective system for simulating the working conditions of the submodule of the cascaded converter and a corresponding current control method are needed in the field.
Disclosure of Invention
The invention provides a current Control method of a cascade submodule working condition simulation system suitable for NLC (Nearest Level approximation modulation), and provides a cascade converter submodule working condition simulation system suitable for NLC and a test method of a cascade converter submodule suitable for NLC based on a current Control method of the cascade submodule working condition simulation system suitable for NLC.
The invention is realized by the following technical scheme.
According to one aspect of the invention, a current control method of a working condition simulation system of a cascaded converter submodule applicable to NLC is provided, wherein the current control method is used for offsetting the feedforward voltage in a current controller and counteracting the pulse voltage interference of a port of an object to be measured caused by the nearest level approximation modulation; wherein:
the feedforward voltage for compensation is generated by any one of the following:
in the first mode, a feedforward voltage is generated by calculating the difference value of the number of input sub-modules in the inversion type sub-module to be tested and the number of input sub-modules in the rectification type sub-module to be tested and combining the capacitance voltage of each sub-module;
-a second way: firstly, sampling a port pulse voltage signal of a port of an object to be detected by a voltage sampler; low-pass filtering is carried out on the voltage signal obtained by sampling so as to filter out sampling errors caused by a switch dead zone; finally, the voltage signal after low-pass filtering is used as a feedforward voltage;
the feedforward voltage which changes synchronously with the pulse voltage of the port of the object to be detected is compensated to the output end of a Proportional Integral Resonance (PIR) regulator in the current controller, so that the interference caused by the pulse voltage of the port of the object to be detected is counteracted, and the current distortion caused by the pulse voltage interference is avoided.
Preferably, the first mode includes:
firstly, reading the on-off states of all submodules of an inversion type and rectification type submodule group to be tested in an object to be tested at the next moment, wherein the on-off state is marked as 1, and the off-off state is marked as 0; then, calculating the difference value between the sum of the on-off states of all the sub-modules in the inversion model sub-module group to be tested and the sum of the on-off states of all the sub-modules in the rectification model sub-module group to be tested; and finally, multiplying the difference value of the sum of the on-off states by the voltage of a single submodule to generate the feedforward voltage required by current control at the next moment.
Preferably, in the first mode, the generated feedforward voltage is expressed by the formula:
u'DUT＝Uc×(ninv-nrec)
in formula (II) u'DUTFor the feed-forward voltage for compensation, UcIs the DC component of the sub-module capacitor voltage, ninvThe number n of sub-modules to be put into the sub-module group to be tested at the next moment of the inversion modelrecAnd the number of the sub-modules is added for the next moment of the rectification type sub-module group to be tested.
Preferably, in the first mode, the capacitor voltage of a single submodule required for generating the feedforward voltage is obtained through a system parameter model of the working condition simulation system of the submodule of the cascaded converter, or obtained by sampling the capacitor voltage of the single submodule.
Preferably, in the second mode, the generated feedforward voltage can be expressed by the formula:
Figure BDA0002674058590000031
in formula (II) u'DUTFor the feed-forward voltage used for compensation, uDUTSampling the resulting port voltage, ω, for a port voltage sampler0S is the complex variable in the transfer function for the cut-off frequency of the low-pass filter.
Preferably, in the second mode, the cut-off frequency of the low-pass filter used for low-pass filtering the sampled voltage signal is selected to be 1/10 to 1/100 of the frequency of the high-frequency voltage pulse caused by the dead zone of the switch.
Preferably, in the second mode, the low-pass filter for low-pass filtering the sampled voltage signal is implemented by an analog circuit or a digital circuit.
Preferably, the method for compensating the feedforward voltage in the current controller to counteract the pulse voltage interference of the port of the object to be measured includes the following control processes:
Figure BDA0002674058590000041
in the formula,
Figure BDA0002674058590000042
for bridge arm current reference values, i, flowing into submodulesarmFor the bridge arm current signal, Δ i is the difference between the reference value of the bridge arm current and the bridge arm current signal, uPIRIs the output value of the proportional-integral resonance regulator, u'DUTFor the feed-forward voltage used for compensation, umIs the modulation voltage, omega, of a current generator1Is the current frequency one, omega2Current frequency of two, KPiIs a proportional control coefficient of a current controller, KIiIs an integral control coefficient of a current controller, Kri1A resonance control coefficient, K, corresponding to a current frequency one for the current controllerri2And s is a complex variable in the transfer function, and is a resonance control coefficient of the current controller corresponding to the current frequency II.
According to another aspect of the invention, a working condition simulation system of a cascaded converter submodule suitable for nearest level approximation modulation is provided, and pulse voltage interference of a port of an object to be measured, which is caused by nearest level approximation modulation, is counteracted by adopting the current control method;
the system comprises:
the system parameter model is used for outputting a reference current signal and a reference voltage signal to the current controller and the voltage controller according to the bridge arm current, the bridge arm voltage and the capacitance voltage of the actual cascade converter to be simulated, and outputting a capacitance voltage signal of a single submodule in an object to be tested, wherein the capacitance voltage signal is used for generating a feedforward voltage;
the current generator is used for receiving the switching sequence input by the current controller and outputting bridge arm current required by the working condition simulation system;
the object to be tested comprises an inversion type sub-module group to be tested and a rectification type sub-module group to be tested of a cascade type converter, wherein the inversion type sub-module group and the rectification type sub-module group to be tested are respectively composed of a plurality of sub-modules working in an inversion state and a rectification state, and are connected with the current generator in series in a main circuit of the working condition simulation system;
the current controller receives a bridge arm current signal input by the current generator, a compensated feedforward voltage signal and a reference current signal input by the system parameter model, and outputs a switching sequence for controlling the current generator through a controller and a modulator link so that the bridge arm current in the system to be tested tracks the reference current signal;
the voltage controller receives a capacitance voltage signal of each submodule output by the object to be detected, a bridge arm current signal actually input by the current generator and a reference voltage signal input by the system parameter model, and outputs a switch sequence for controlling the submodule to be detected, so that the submodule capacitance voltage in the two submodule groups of the object to be detected tracks the reference voltage signal;
the port voltage sampler is used for sampling voltage difference signals of the ports of the two sub-module groups to be tested and outputting the voltage difference signals obtained by sampling;
and the low-pass filter receives the voltage difference signal input by the port voltage sampler, performs low-pass filtering on the received voltage difference signal, and outputs the filtered voltage difference signal to the current controller.
Preferably, the system parameter model is obtained by any one or more of the following methods:
obtaining through theoretical calculation of the cascade type converter;
obtaining through simulation of a cascade type converter system;
the method is obtained through practical experiments on the cascade type converter system.
Preferably, the current generator comprises a direct-current power supply and a controllable full-bridge or half-bridge type switch circuit, and the bridge arm current in the working condition simulation system is controlled by controlling the on-off of the full-bridge or half-bridge circuit.
Preferably, in the object to be tested, the number of the sub-modules included in the sub-module group to be tested of the inverter type and the rectifier type is adjusted within the total number of the sub-modules of the single bridge arm of the simulated actual cascaded converter according to actual needs.
Preferably, the circuit structures of the neutron modules of the inversion type and rectification type objects to be detected adopt a full-bridge structure and/or a half-bridge structure.
Preferably, the control method in the current controller adopts proportional-integral resonance control, and the Modulation method of the output voltage adopts Sinusoidal Pulse Width Modulation (SPWM).
Preferably, the voltage modulation method of the cascaded converter submodule working condition simulation system comprises the following steps: a nearest level approximation Modulation method and a Carrier Phase Shift-single Pulse Width Modulation method.
Preferably, the method for the voltage controller to output the switching sequence is as follows:
sampling the capacitance voltage of all sub-modules in an object to be measured, subtracting the capacitance voltage reference signal in the voltage reference signal from the obtained average value of the capacitance voltage of the inversion type sub-module to be measured and the rectification type sub-module to be measured, inputting the difference value into a Proportional Integral regulator (PI), compensating the output of the PI to a bridge arm voltage reference signal in the voltage reference signal, and finally generating a switch sequence by a nearest level approximation modulation method or a carrier phase shift modulation method according to the compensated modulation voltage so as to control the capacitance voltage of all sub-modules in the object to be measured.
According to a third aspect of the present invention, a testing method for a cascaded converter submodule suitable for nearest level approximation modulation is provided, wherein the cascaded converter submodule is tested by using any one of the current control methods based on any one of the cascaded converter submodule working condition simulation systems.
Compared with the prior art, the invention has the following beneficial effects:
the current control method of the cascade type converter submodule working condition simulation system suitable for NLC (nearest level approximation modulation) and the test method of the cascade type converter submodule working condition simulation system and the cascade type converter submodule realized based on the current control method generate the feedforward voltage through a calculation or sampling mode, and compensate the feedforward voltage into the current controller.
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Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments with reference to the following drawings:
fig. 1 is a schematic structural diagram of a working condition simulation system of a cascaded converter submodule for generating a feed-forward voltage by calculating an input number difference (a first manner) according to a preferred embodiment of the present invention;
fig. 2 is a schematic structural diagram of a working condition simulation system of a cascaded converter submodule for generating a feedforward voltage (in a second manner) by using sampling filtering according to a preferred embodiment of the present invention;
fig. 3 is a schematic diagram of a topology structure of a main circuit in a working condition simulation system of a cascaded converter sub-module according to a preferred embodiment of the present invention;
FIG. 4 is a schematic block diagram of a current controller in a condition simulation system of a cascaded converter sub-module according to a preferred embodiment of the present invention;
fig. 5 is a block diagram of a current control loop of a working condition simulation system of a cascaded converter submodule according to a preferred embodiment of the present invention;
fig. 6 is a schematic block diagram of a voltage controller in a working condition simulation system of a cascaded converter submodule provided in a preferred embodiment of the present invention;
in the figure: 1-system parameter model; 2-a current generator; 3-an object to be measured; 4-a current controller; 5-a voltage controller; a 6-port voltage sampler; 7-low pass filter.
Detailed Description
The following examples illustrate the invention in detail: the embodiment is implemented on the premise of the technical scheme of the invention, and a detailed implementation mode and a specific operation process are given. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention.
The embodiment of the invention provides a current control method of a working condition simulation system of a cascaded converter submodule applicable to NLC (non-line-variable) by adopting a feedforward voltage compensation method and compensating feedforward voltage in a current controller to counteract pulse voltage interference of a port of an object to be measured caused by nearest level approximation modulation. The method is suitable for a working condition simulation system of a cascaded converter submodule working under the nearest level approximation modulation and having the following structure, as shown in fig. 1 and fig. 2, the method is a structural schematic diagram of the working condition simulation system (simulation test circuit for short) of the cascaded converter submodule built in the embodiment of the invention, and the system structure comprises:
the system parameter model 1 is used for outputting a reference current signal and a reference voltage signal to a current controller and a voltage controller according to bridge arm current, bridge arm voltage and capacitance voltage of an actual cascade converter to be simulated, and outputting a capacitance voltage signal of a single submodule in an object to be tested;
the current generator 2 is used for receiving the switching sequence input by the current controller and outputting bridge arm current required by the working condition simulation system;
the object to be tested 3 comprises an inversion type sub-module group to be tested and a rectification type sub-module group to be tested of the cascade type converter, wherein the inversion type sub-module group and the rectification type sub-module group to be tested are respectively composed of a plurality of sub-modules working in an inversion state and a rectification state, and are connected with the current generator in series in a main circuit of the working condition simulation system, and the inversion type sub-module group and the rectification type sub-module group are respectively used for receiving bridge arm current input by the current generator and a switch sequence input by the voltage controller and outputting the number of sub-modules input into the current generator and capacitor voltage of each sub-module;
the current controller 4 receives a bridge arm current signal input by the current generator, a compensated feedforward voltage signal and a reference current signal input by the system parameter model, and outputs a switching sequence for controlling the current generator through a controller and a modulator link so that the bridge arm current in the system to be tested tracks the reference current signal;
the voltage controller 5 is used for receiving a capacitance voltage signal of a submodule of the object to be detected, a bridge arm current signal actually input by the current generator and a reference voltage signal input by the system parameter model, and outputting a switch sequence for controlling the submodule to be detected, so that submodule capacitance voltage in two submodule groups of the object to be detected tracks the reference voltage signal;
the port voltage sampler 6 is used for sampling voltage difference signals of the ports of the two sub-module groups to be tested and outputting the voltage difference signals obtained by sampling;
and a low pass filter 7 receiving the voltage difference signal input by the port voltage sampler, performing low pass filtering on the received voltage difference signal, and outputting the filtered voltage difference signal to the current controller.
As a preferred embodiment, the system parameter model 1 is intended to give a reference current and a reference voltage of a working condition simulation system of the cascaded converter according to a bridge arm current, a bridge arm voltage and a capacitance voltage of an actual cascaded converter.
As a preferred embodiment, the system parameter model 1 is obtained by any one or more of the following methods:
obtaining through theoretical calculation of the cascade type converter;
obtaining through simulation of a cascade type converter system;
the method is obtained through practical experiments on the cascade type converter system.
As a preferred embodiment, the current generator 2 includes a dc power supply and a controllable full-bridge or half-bridge switching circuit, and controls the bridge arm current in the operating condition simulation system by controlling the on/off of the full-bridge or half-bridge switching circuit.
As a preferred embodiment, in the object to be measured 3, the number of sub-modules included in the sub-module groups to be measured of the inverter type and the rectifier type is adjusted within the total number of sub-modules of a single bridge arm of the simulated actual cascaded converter according to actual needs.
Wherein, adjusting within the total number of the sub-modules according to actual needs means: the number of the sub-modules contained in the sub-module group to be tested of the inversion type and the rectification type can be the same or different, and can be a single sub-module or a plurality of sub-modules connected in series, but the total number is unchanged.
As a preferred embodiment, in the object to be measured 3, the circuit structures of the neutron modules of the inversion type and rectification type objects to be measured are full-bridge structures, half-bridge structures or a combination structure of the full-bridge structures and the half-bridge structures.
As a preferred embodiment, the current control method in the current controller 4 adopts proportional-integral resonance control, and the modulation method of the output voltage adopts sinusoidal pulse width modulation.
In a preferred embodiment, the current controller 4 receives the current reference signal, the bridge arm current signal and the feedforward voltage signal, and outputs a switching sequence to control the current generator 2 to output the required current. Therefore, the bridge arm current in the working condition simulation system is the same as the simulated bridge arm current in the actual cascaded converter system.
As a preferred embodiment, the current controller 4 specifically works in a process that the current controller 4 inputs a difference value between a read bridge arm reference current signal and a calculated or sampled feedforward voltage to the proportional-integral resonant controller, compensates the read feedforward voltage signal to an output end of the proportional-integral resonant controller, and finally generates a corresponding switching sequence through SPWM modulation according to the compensated modulation voltage to control the current generator 2.
As a preferred embodiment, the voltage controller 5 receives the capacitance voltage signal of the submodule group to be tested, the bridge arm current signal, and the capacitance voltage reference value and the bridge arm voltage reference value of the simulated system, and outputs the switching signal of the submodule group to be tested based on a nearest level approximation modulation method or a carrier phase shift modulation method.
As a preferred embodiment, the method for outputting the switching sequence by the voltage controller is as follows:
sampling the capacitance voltages of all sub-modules in an object to be detected, subtracting the capacitance voltage reference signal in the voltage reference signal from the obtained average value of the capacitance voltages of the inversion type sub-module group to be detected and the rectification type sub-module group to be detected, inputting the difference value into a proportional-integral regulator, compensating the output of the proportional-integral regulator to a bridge arm voltage reference signal in the voltage reference signal, and finally generating a switch sequence by a nearest level approximation modulation method or a carrier phase shift modulation method according to the compensated modulation voltage so as to control the capacitance voltages of all sub-modules in the object to be detected.
According to the current control method of the cascade submodule working condition simulation system suitable for NLC, provided by the embodiment of the invention, the pulse voltage interference of a port of an object to be measured, which is caused by nearest level approximation modulation, is counteracted by compensating feedforward voltage in a current controller; the feedforward voltage which changes synchronously with the pulse voltage of the port of the object to be detected is compensated to the output end of the proportional-integral resonance regulator in the current controller, so that the interference caused by the pulse voltage of the port of the object to be detected is counteracted, and the current distortion caused by the pulse voltage interference is avoided.
Wherein:
the feedforward voltage for compensation is generated by any one of the following:
the first feedforward voltage generation method is that the feedforward voltage is generated by calculating the difference value of the number of input sub-modules in the inversion type sub-module group to be tested and the number of input sub-modules in the rectification type sub-module group to be tested and combining the capacitance voltage of a single sub-module, and the process of performing feedforward voltage compensation by the method is shown in fig. 1.
As a preferred embodiment, the feedforward voltage generation method includes reading on-off states of all sub-modules in an inversion type and rectification type sub-module group to be tested in an object to be tested 3 at the next moment, wherein the on state is recorded as 1, and the off state is recorded as 0; then, calculating the difference value between the sum of the on-off states of all the sub-modules in the inversion model sub-module group to be tested and the sum of the on-off states of all the sub-modules in the rectification model sub-module group to be tested; and finally, multiplying the difference value of the sum of the on-off states by the voltage of a single submodule to generate the feedforward voltage required by current control at the next moment.
As a preferred embodiment, the feedforward voltage generation method can be expressed by the following equation:
u'DUT＝Uc×(ninv-nrec)
in formula (II) u'DUTFor the feed-forward voltage for compensation, UcIs the DC component of the sub-module capacitor voltage, ninvThe number n of sub-modules to be put into the sub-module group to be tested at the next moment of the inversion modelrecAnd the number of the sub-modules is added for the next moment of the rectification type sub-module group to be tested.
The second feedforward voltage generation method is to sample the port voltage signal of the object to be measured 3 and perform low-pass filtering on the sampled voltage signal to generate a feedforward voltage, and the process of performing feedforward voltage compensation by the second feedforward voltage generation method is shown in fig. 2.
As a preferred embodiment, the feedforward voltage generating method is that, first, a port pulse voltage signal of a port of an object to be measured, that is, a voltage difference signal between a node 1 and a node 2 in fig. 3 is sampled by a port voltage sampler 6; then, the sampled voltage signal is subjected to low-pass filtering through a low-pass filter 7 so as to filter out sampling errors caused by a switch dead zone; and finally, taking the voltage signal after low-pass filtering as a feedforward voltage.
As a preferred embodiment, the feedforward voltage generation method can be expressed by the following equation:
Figure BDA0002674058590000091
in formula (II) u'DUTFor the feed-forward voltage used for compensation, uDUTSampling the resulting port voltage, ω, for a port voltage sampler0S is the complex variable in the transfer function for the cut-off frequency of the low-pass filter.
When a recent level approximation modulation method is adopted in a cascade type converter submodule working condition simulation system, a switch dead zone can cause voltage signals at two ends of a submodule group to be detected to generate high-frequency voltage pulses, the pulse width of the high-frequency pulses is extremely narrow, the interference on a current controller is very small, if the high-frequency voltage pulses are sampled and compensated to the current controller, the current controller is subjected to larger interference due to the delay of the compensated high-frequency pulse voltage and the actual high-frequency pulse voltage, and therefore after the voltages at two ends of the submodule group to be detected are obtained through sampling, low-pass filtering is carried out on the sampled signals through a low-pass filter 7, and therefore the high-frequency pulse voltage is eliminated in compensation voltage.
According to the current control method provided by the embodiment of the invention, the feed-forward voltage is compensated in the current controller 4, so that the pulse voltage interference of the port of the object to be measured, which is caused by the nearest level approximation modulation, is counteracted.
Specifically, the current control method may be expressed as compensating the obtained feedforward voltage signal to the output end of the proportional-integral resonant regulator in the current controller 4, and finally performing sine pulse width modulation according to the compensated regulator output signal to output a corresponding switching sequence for controlling the current generator 2, where the control process is as shown in fig. 4. The whole control process can be expressed by the following formula:
Figure BDA0002674058590000101
wherein,
Figure BDA0002674058590000102
for bridge arm current reference values, i, flowing into submodulesarmFor the bridge arm current signal, Δ i is the difference between the reference value of the bridge arm current and the bridge arm current signal, uPIRIs the output value of the proportional-integral resonance regulator, u'DUTFeed forward voltage signal umIs the modulation voltage, omega, of a current generator1Is the current frequency one, omega2Current frequency of two, KPiIs a proportional control coefficient of a current controller, KIiIs an integral control coefficient of a current controller, Kri1Is the resonance control coefficient, K, of the current controller corresponding to the current frequency oneri2And the resonance control coefficient is the resonance control coefficient of the current controller corresponding to the power frequency two.
The block diagram of the whole bridge arm current control loop is shown in fig. 5, and it can be obviously seen that after the compensation voltage is added, the influence of the pulse voltage at the two ends of the object to be detected on the current control loop is counteracted by the compensation voltage, so that the interference of the pulse voltage can be inhibited, and the bridge arm current output by the system can stably track the reference current.
In some embodiments of the present invention, the constructed working condition simulation system is used to simulate the working condition of the neutron module of the actual cascaded converter, so that the electrical characteristics of the sub-module to be tested (i.e. the object to be tested) in the working condition simulation system are the same as those of the sub-module in the actual cascaded converter, and thus the working condition of the neutron module of the actual cascaded converter can be evaluated by the constructed working condition simulation system.
In some embodiments of the present invention, the voltage modulation method of the operating condition simulation system of the sub-module of the Cascaded Converter may adopt, but is not limited to, a nearest level approximation modulation method and a carrier phase shift modulation method, and may simulate, but is not limited to, a Cascaded Converter, where the sub-module structure to be simulated includes, but is not limited to, a half Bridge, a full Bridge Modular Multilevel Converter (MMC), and a Cascaded H-Bridge Converter (CHB).
In some embodiments of the present invention, the current control method is suitable for being used with a voltage control method that stably controls the capacitance voltage of an object to be measured through a proportional-integral regulator based on a nearest level approximation modulation method.
Specifically, the capacitance voltage signals of all the sub-modules in the object 3 to be measured are sampled and input to the voltage controller 5. As shown in fig. 6, in the voltage controller 5, the capacitance voltage reference value is subtracted from the average value of the capacitance voltages read from the inversion and rectification sub-module groups to be tested, the difference value is input to the proportional-integral regulator, the output of the proportional-integral regulator is compensated to the bridge arm voltage reference value, and finally the object to be tested 3 is controlled by the modulation method of nearest level approximation, and the formula corresponding to the inversion sub-module group to be tested can be expressed as:
Figure BDA0002674058590000111
the formula corresponding to the rectification type sub-module group to be tested can be expressed as follows:
Figure BDA0002674058590000112
wherein n is the number of all sub-modules in the object to be tested, ucinv_iAnd ucrec_iRespectively are capacitance voltage signals of the ith sub-module in the inversion model sub-module group to be tested and the rectification model sub-module group to be tested,
Figure BDA0002674058590000113
and
Figure BDA0002674058590000114
respectively is the average value of capacitance voltage signals of i sub-modules in the inversion model sub-module group to be tested and the rectification model sub-module group to be tested,
Figure BDA0002674058590000115
and
Figure BDA0002674058590000116
respectively is a sub-module capacitance voltage reference value, delta u, in the inversion type sub-module group to be tested and the rectification type sub-module group to be testedinvAnd Δ urecDifference value u between the capacitor voltage reference value in the inversion type sub-module to be tested and the average value of the sub-module capacitor voltage signals in the rectification type sub-module to be testedPI_invAnd uPI_recRespectively output signals of proportional-integral regulators in the inversion model sub-module to be tested and the rectification model sub-module to be tested,
Figure BDA0002674058590000121
and
Figure BDA0002674058590000122
the reference values u of bridge arm voltages in the inverter model sub-module group to be tested and the rectifier model sub-module group to be testedm_invAnd um_recThe modulation voltage value K used for nearest level approximation in the inverter model sub-module to be tested and the rectifier model sub-module to be testedPuIs a proportional control coefficient of a voltage controller, KIuIs the integral control coefficient of the voltage controller. s is a complex variable in the transfer function.
It should be noted that, the difference between the simulated system capacitor voltage reference value and the capacitor voltage of the object to be measured needs to be compensated to the bridge arm voltage reference value through the proportional-integral regulator, because the total charge and discharge amounts of the sub-module voltages in one period may not be completely equal in the operating process of the working condition simulation system, which may cause the capacitor voltage average value of the sub-modules to continuously increase or decrease, and therefore, the deviation value between the capacitor voltage and the reference capacitor voltage needs to be compensated to stabilize the capacitor voltage of the sub-modules.
Based on the current control method provided by the above embodiment of the present invention, another embodiment of the present invention provides a working condition simulation system of a cascaded converter submodule suitable for NLC, where the system employs any one of the current control methods described in the above embodiments to cancel pulse voltage interference at a port of an object to be measured, which is caused by nearest level approximation modulation.
Based on the current control method and the system for simulating the working condition of the cascaded converter submodule provided by the embodiments of the invention, the third embodiment of the invention provides a method for testing the cascaded converter submodule suitable for NLC, and the testing of the cascaded converter submodule is realized by applying any one or more systems and/or methods.
The current control method of the cascade converter submodule working condition simulation system applicable to NLC (nearest level approximation modulation) provided by the above embodiment of the present invention generates the feedforward voltage by calculation or sampling, and compensates the feedforward voltage into the current controller to generate the feedforward voltage, including: the method I comprises the steps of calculating the difference value of the number of the two sub-module groups to be tested which are put into the sub-modules, and multiplying the difference value by the capacitor voltage of a single sub-module, so that the feedforward voltage is generated. And secondly, sampling a voltage signal of the port of the object to be measured, performing low-pass filtering on the voltage signal, and taking the filtered voltage signal as a feedforward voltage. Because the generated feedforward voltage and the on-off state of the submodule to be tested are changed synchronously, the interference of the pulse voltage of the port of the object to be tested caused by the recent level approaching modulation can be better counteracted, the distortion of the current caused by the pulse voltage is avoided, and the method does not need to add an additional auxiliary circuit, thereby reducing the complexity of control, saving the manufacturing cost of a working condition simulation system and being a valuable technical improvement.
The foregoing description of specific embodiments of the present invention has been presented. It is to be understood that the present invention is not limited to the specific embodiments described above, and that various changes and modifications may be made by one skilled in the art within the scope of the appended claims without departing from the spirit of the invention.

Claims (16)

1. A current control method of a cascade submodule working condition simulation system suitable for NLC is characterized in that feedforward voltage is compensated in a current controller, and the feedforward voltage plays a compensation role in the current controller to counteract pulse voltage interference of a port of an object to be measured caused by nearest level approximation modulation; wherein:
the feedforward voltage for compensation is generated by any one of the following:
-a first way: calculating the difference value of the number of input sub-modules in the inversion model sub-module group to be tested and the number of input sub-modules in the rectification model sub-module group to be tested, and combining the capacitance voltage of a single sub-module to generate a feedforward voltage;
-a second way: firstly, sampling a port pulse voltage signal of a port of an object to be detected by a voltage sampler; low-pass filtering is carried out on the voltage signal obtained by sampling so as to filter out sampling errors caused by a switch dead zone; finally, the voltage signal after low-pass filtering is used as a feedforward voltage;
the feedforward voltage which changes synchronously with the pulse voltage of the port of the object to be detected is compensated to the output end of the proportional-integral resonance regulator in the current controller, so that the interference caused by the pulse voltage of the port of the object to be detected is counteracted, and the current distortion caused by the pulse voltage interference is avoided.
2. The current control method of the NLC-applicable cascade submodule working condition simulation system according to claim 1, wherein the first mode comprises the following steps:
firstly, reading the on-off states of all submodules of an inversion type and rectification type submodule group to be tested in an object to be tested at the next moment, wherein the on-off state is marked as 1, and the off-off state is marked as 0; then, calculating the difference value between the sum of the on-off states of all the sub-modules in the inversion model sub-module group to be tested and the sum of the on-off states of all the sub-modules in the rectification model sub-module group to be tested; and finally, multiplying the difference value of the sum of the on-off states by the voltage of a single submodule to generate the feedforward voltage required by current control at the next moment.
3. The current control method of the NLC-applicable cascade submodule working condition simulation system according to claim 1, wherein in the first mode, the generated feedforward voltage is expressed by a formula:
u'DUT＝Uc×(ninv-nrec)
in formula (II) u'DUTFor the feed-forward voltage for compensation, UcIs the DC component of the sub-module capacitor voltage, ninvThe number n of sub-modules to be put into the sub-module group to be tested at the next moment of the inversion modelrecAnd the number of the sub-modules is added for the next moment of the rectification type sub-module group to be tested.
4. The current control method of the cascade-type submodule working condition simulation system suitable for NLC according to claim 1, wherein in the first mode, the single submodule capacitor voltage required for generating the feedforward voltage is obtained by a system parameter model of the cascade-type converter submodule working condition simulation system, or by sampling the capacitor voltage of the single submodule.
5. The current control method of the NLC-adapted cascaded submodule working condition simulation system according to claim 1, wherein in the second mode, the generated feedforward voltage can be expressed by a formula:
Figure FDA0003100175060000021
in formula (II) u'DUTFor the feed-forward voltage used for compensation, uDUTSampling the resulting port voltage, ω, for a port voltage sampler0S is the complex variable in the transfer function for the cut-off frequency of the low-pass filter.
6. The current control method of the cascade-type submodule working condition simulation system suitable for NLC according to claim 1, wherein in the second mode, the cut-off frequency of the low-pass filter used for low-pass filtering the sampled voltage signal is selected from 1/10 to 1/100 of the high-frequency voltage pulse frequency caused by the switch dead zone.
7. The current control method of the cascade-type submodule working condition simulation system suitable for NLC according to claim 1, wherein in the second mode, the low-pass filter for low-pass filtering the sampled voltage signal is implemented by an analog circuit or a digital circuit.
8. The current control method of the NLC-adapted cascaded submodule working condition simulation system according to any one of claims 1 to 7, wherein the method compensates a feedforward voltage in a current controller, the feedforward voltage is compensated in the current controller to counteract pulse voltage interference of a port of an object to be measured, and the method is expressed by a formula:
Figure FDA0003100175060000022
in the formula,
Figure FDA0003100175060000023
for bridge arm current reference values, i, flowing into submodulesarmFor the bridge arm current signal, Δ i is the difference between the reference value of the bridge arm current and the bridge arm current signal, uPIRIs the output value of the proportional-integral resonance regulator, u'DUTFor the feed-forward voltage used for compensation, umIs the modulation voltage, omega, of a current generator1Is the current frequency one, omega2Current frequency of two, KPiIs a proportional control coefficient of a current controller, KIiIs an integral control coefficient of a current controller, Kri1A resonance control coefficient, K, corresponding to a current frequency one for the current controllerri2And s is a complex variable in the transfer function, and is a resonance control coefficient of the current controller corresponding to the current frequency II.
9. A working condition simulation system of a cascaded converter submodule suitable for NLC is characterized in that the current control method of any one of claims 1 to 8 is adopted to counteract pulse voltage interference of a port of an object to be measured caused by nearest level approximation modulation;
the system comprises:
the system parameter model is used for outputting a reference current signal and a reference voltage signal to the current controller and the voltage controller according to the bridge arm current, the bridge arm voltage and the capacitance voltage of the actual cascade converter to be simulated, and outputting a capacitance voltage signal of a single submodule in an object to be tested, wherein the capacitance voltage signal is used for generating a feedforward voltage;
the current generator is used for receiving the switching sequence input by the current controller and outputting bridge arm current required by the working condition simulation system;
the object to be tested comprises an inversion type sub-module group to be tested and a rectification type sub-module group to be tested of a cascade type converter, wherein the inversion type sub-module group and the rectification type sub-module group to be tested are respectively composed of a plurality of sub-modules working in an inversion state and a rectification state, and are connected with the current generator in series in a main circuit of the working condition simulation system;
the current controller receives a bridge arm current signal input by the current generator, a compensated feedforward voltage signal and a reference current signal input by the system parameter model, and outputs a switching sequence for controlling the current generator through a controller and a modulator link so that the bridge arm current in the system to be tested tracks the reference current signal;
the voltage controller receives a capacitance voltage signal of each submodule output by the object to be detected, a bridge arm current signal actually input by the current generator and a reference voltage signal input by the system parameter model, and outputs a switch sequence for controlling the submodule to be detected, so that the submodule capacitance voltage in the two submodule groups of the object to be detected tracks the reference voltage signal;
the port voltage sampler is used for sampling voltage difference signals of the ports of the two sub-module groups to be tested and outputting the voltage difference signals obtained by sampling;
and the low-pass filter receives the voltage difference signal input by the port voltage sampler, performs low-pass filtering on the received voltage difference signal, and outputs the filtered voltage difference signal to the current controller.
10. The system for simulating the working conditions of the cascaded converter submodule suitable for NLC of claim 9, wherein the system parameter model is obtained by any one or more of the following methods:
obtaining through theoretical calculation of the cascade type converter;
obtaining through simulation of a cascade type converter system;
the method is obtained through practical experiments on the cascade type converter system.
11. The system of claim 9, wherein the current generator comprises a dc power supply and a controllable full-bridge or half-bridge switching circuit, and the system controls the bridge arm current in the system by controlling the on/off of the full-bridge or half-bridge switching circuit.
12. The system according to claim 9, wherein the number of submodules included in the submodule groups to be tested for inverting and rectifying in the object to be tested is adjusted within the total number of submodules of a single bridge arm of the actual cascaded converter according to actual needs.
13. The system of claim 9, wherein the circuit structures of the neutron modules of the inversion-type and rectification-type objects to be tested are full-bridge structures and/or half-bridge structures.
14. The NLC-adapted cascaded converter submodule condition simulation system according to claim 9, wherein a current control method in the current controller adopts proportional-integral resonance control, and a modulation method of output voltage adopts sine pulse width modulation.
15. The cascaded converter submodule working condition simulation system of claim 9, wherein the voltage modulation method of the cascaded converter submodule working condition simulation system comprises: a nearest level approximation modulation method and a carrier phase shift modulation method; and/or
The method for outputting the switching sequence by the voltage controller comprises the following steps:
sampling the capacitance voltages of all sub-modules in an object to be detected, subtracting the capacitance voltage reference signal in the voltage reference signal from the obtained average value of the capacitance voltages of the inversion type sub-module group to be detected and the rectification type sub-module group to be detected, inputting the difference value into a proportional-integral regulator, compensating the output of the proportional-integral regulator to a bridge arm voltage reference signal in the voltage reference signal, and finally generating a switch sequence by a nearest level approximation modulation method or a carrier phase shift modulation method according to the compensated modulation voltage so as to control the capacitance voltages of all sub-modules in the object to be detected.
16. A testing method of a cascaded converter submodule suitable for NLC is characterized in that based on the cascaded converter submodule working condition simulation system suitable for NLC of any one of claims 9 to 15, the cascaded converter submodule is tested through the current control method of the cascaded converter submodule working condition simulation system suitable for NLC of any one of claims 1 to 8.
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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112636620B (en) * 2020-12-03 2022-05-03 上海交通大学 Method for generating nearest level approximation control signal for working condition simulation of cascaded converter
CN113176428B (en) * 2021-03-16 2022-05-03 上海交通大学 Current distortion eliminating system and method for working condition simulation of cascaded converter

Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105186897A (en) * 2015-08-20 2015-12-23 华中科技大学 Nearest level control method for modularized multi-level converter
CN106787884A (en) * 2017-01-24 2017-05-31 特变电工新疆新能源股份有限公司 Pressure modulator approach and press modulating device that nearest level is approached
CN107196327A (en) * 2017-07-12 2017-09-22 华北电力科学研究院有限责任公司 The feed forward control method of suppression module voltage-source type converter valve oscillation of power
CN107677956A (en) * 2017-09-29 2018-02-09 山东建筑大学 A kind of current control method of flexible DC power transmission MMC converter valve operating test devices
JP6359213B1 (en) * 2017-06-27 2018-07-18 三菱電機株式会社 Power converter
CN109217687A (en) * 2018-08-24 2019-01-15 南京理工大学 Power distribution network electric power electric transformer and its control method based on MMC
CN109347352A (en) * 2018-11-21 2019-02-15 上海交通大学 Cascade converter submodule capacitor voltage balance control method
CN109709434A (en) * 2019-01-29 2019-05-03 上海交通大学 The test circuit of cascade converter multi-tool block multi-state simulation
CN109709363A (en) * 2019-01-29 2019-05-03 上海交通大学 The control method and system of cascade converter multi-tool block multi-state simulation device
CN110488115A (en) * 2019-07-23 2019-11-22 上海交通大学 The single-phase test circuit of cascade converter submodule based on symmetrical bridge arm structure
CN110850194A (en) * 2019-10-15 2020-02-28 上海交通大学 Working condition simulation test circuit and method for cascaded converter submodule
CN111030496A (en) * 2019-04-04 2020-04-17 沈阳工业大学 Variable carrier hybrid modulation method suitable for modular multilevel converter

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105186897A (en) * 2015-08-20 2015-12-23 华中科技大学 Nearest level control method for modularized multi-level converter
CN106787884A (en) * 2017-01-24 2017-05-31 特变电工新疆新能源股份有限公司 Pressure modulator approach and press modulating device that nearest level is approached
JP6359213B1 (en) * 2017-06-27 2018-07-18 三菱電機株式会社 Power converter
CN107196327A (en) * 2017-07-12 2017-09-22 华北电力科学研究院有限责任公司 The feed forward control method of suppression module voltage-source type converter valve oscillation of power
CN107677956A (en) * 2017-09-29 2018-02-09 山东建筑大学 A kind of current control method of flexible DC power transmission MMC converter valve operating test devices
CN109217687A (en) * 2018-08-24 2019-01-15 南京理工大学 Power distribution network electric power electric transformer and its control method based on MMC
CN109347352A (en) * 2018-11-21 2019-02-15 上海交通大学 Cascade converter submodule capacitor voltage balance control method
CN109709434A (en) * 2019-01-29 2019-05-03 上海交通大学 The test circuit of cascade converter multi-tool block multi-state simulation
CN109709363A (en) * 2019-01-29 2019-05-03 上海交通大学 The control method and system of cascade converter multi-tool block multi-state simulation device
CN111030496A (en) * 2019-04-04 2020-04-17 沈阳工业大学 Variable carrier hybrid modulation method suitable for modular multilevel converter
CN110488115A (en) * 2019-07-23 2019-11-22 上海交通大学 The single-phase test circuit of cascade converter submodule based on symmetrical bridge arm structure
CN110850194A (en) * 2019-10-15 2020-02-28 上海交通大学 Working condition simulation test circuit and method for cascaded converter submodule

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
"A Novel Harmonic Control Method for MMC Combining Improved Nearest Level Control and Selective Harmonic Elimination method";Yu Jin1等;《IEEE》;20191231;第6368-6375页 *
"Improved Voltage Balancing Method Based on MMC Nearest Level Modulation";Zhui Liu等;《Proceedings of the 36th Chinese Control Conference》;20171231;第10359-10364页 *
"基于NLC调制的MMC多子模块工况模拟测试电路及其控制方法";杨云霄等;《全球能源互联网》;20200331;第3卷(第2期);第199-204页 *

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