WO2019076166A1

WO2019076166A1 - Nonlinear load power output device

Info

Publication number: WO2019076166A1
Application number: PCT/CN2018/104726
Authority: WO
Inventors: 肖伟峰
Original assignee: 广东东方电讯科技有限公司
Priority date: 2017-10-16
Filing date: 2018-09-08
Publication date: 2019-04-25
Also published as: CN107677894B; CN107677894A

Abstract

A nonlinear load power output device, comprising a main control unit 110, a waveform generator unit 120, and a power amplifier unit 130. The main control unit 110 is used for generating two discrete digital signals from each phase of current according to a control instruction and sending the two discrete digital signals to the waveform generator unit 120, and the waveforms corresponding to the two discrete digital signals are combined into a sine waveform. The main control unit 110 generates current of a nonlinear waveform by means of the waveform generator unit 120, and can synthesize the nonlinear waveforms of two branch circuits into current of a sine waveform by means of a trunk circuit. The measurement of a sine waveform by means of a standard meter is compared with the measurement of a nonlinear waveform by means of a tested meter, thereby implementing standard tracing of nonlinear measurement to a sine wave standard.

Description

Nonlinear load power output device

Technical field

The present invention relates to the field of non-linear waveform power output technology, and more particularly to a non-linear load power output device.

Background technique

There is currently no traceability standard for direct measurement of electrical energy in non-linear load conditions, and it is not possible to measure the accuracy of a meter that measures nonlinear waveforms.

China Institute of Metrology has proposed two indirect test waveforms for the measurement of the dynamic accuracy of electrical energy meters or devices, but since the test waveforms are no longer sinusoidal, the test waveforms of the traceability devices of the traditional standard tables used for reference are Sine waves, so it is impossible to directly prove that the accuracy of this traditional standard meter under non-linear load conditions is "trustworthy".

The conventional power source cannot simultaneously supply the current of the non-linear waveform to the test table, and at the same time, the current of the sinusoidal waveform is supplied to the conventional standard meter, which causes inconvenience to the non-linear waveform current test and causes standard traceability inconvenience.

Summary of the invention

Based on this, it is necessary to provide a non-linear load power output device in a targeted manner.

A nonlinear load power output device includes: a main control unit, a waveform generator unit, and a power amplifier unit;

The main control unit is connected to the waveform generator unit, and the waveform generator unit is connected to the power amplifier unit;

The main control unit is configured to generate a three-phase voltage and a three-phase current signal according to the control instruction, and divide each phase current into two discrete digital signals, and send the discrete digital signals to the waveform generator unit. Wherein, the waveforms corresponding to the two discrete digital signals of each phase current are combined into a complete sine wave waveform;

The waveform generator unit is configured to receive the discrete digital signals, and convert the discrete digital signals into analog signals, and output the analog signals to the power amplifier unit, wherein two of each phase current The waveform corresponding to the analog signal is a non-linear waveform, and the two non-linear waveforms of the same phase current are superimposed to be equal to one complete sine wave waveform;

The power amplifier unit is configured to amplify the analog signal and output through the three voltages and six current outputs.

In one embodiment, further comprising an analog sampling unit and a measurement calculation unit, the power amplifier unit being connected to the analog sampling unit, the analog sampling unit being connected to the measurement calculation unit, the measurement calculation unit and the Main control unit connection;

The analog sampling unit is configured to sample the analog signal output by the power amplifier, convert the sampled analog signal into a digital signal, and send the converted digital signal to the measurement calculation unit ;

The measurement calculation unit is configured to measure the converted digital signal;

The main control unit is further configured to compare the digital signal generated according to the control instruction and the digital signal measured by the measurement calculation unit.

In one embodiment, an input unit is further included, the input unit for receiving a control command, and transmitting the control command to the main control unit.

In one embodiment, the waveform generator unit is configured to convert the three-phase digital signal into a three-phase analog voltage signal and a current signal, wherein the signal of each phase current includes two of the analog signals, and The three-phase analog signals are output to the power amplifier unit, and two of the non-linear waveforms of each phase current are superimposed to be equal to one of the sine wave waveforms.

In one embodiment, the power amplifier unit has an output of three phases, and the current output of each phase includes two of the outputs, and the two outputs of each phase are used to respectively output two of the same phase The analog signals.

In one embodiment, one of the two outputs of the power amplifier unit is for connecting to a test table.

The invention has the beneficial effects that the main control unit generates a current signal according to the input control command, and divides the current of each phase sine wave waveform into two discrete digital signals, and converts the digital signal of each phase current through the waveform generator unit into Corresponding non-linear waveform analog signal output, so that the non-linear waveform current can be measured by measuring the analog signal of one non-linear waveform through the test table; in addition, the main control unit can pass the waveform generator The unit generates the current of the nonlinear waveform, and can also synthesize the nonlinear waveform of the two branches into the current of the sinusoidal waveform through the trunk road, thereby realizing the measurement of the sine wave by the traditional standard table, checking the test table to the nonlinear wave. The measurement is verified to be credible; at the same time, because the traditional standard meter measures sine waves and is standard traceable, it is easy to achieve standard traceability of nonlinear wave measurements.

DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below. Obviously, the drawings in the following description are only It is a certain embodiment of the present invention, and other drawings can be obtained from those skilled in the art without any inventive labor.

1 is a schematic diagram of a circuit principle of a non-linear load power output device according to an embodiment;

2 is a schematic diagram showing the circuit principle of a test circuit in which a non-linear load power output device and a conventional standard meter are combined with another embodiment;

3 is a schematic diagram showing the circuit principle of a test circuit in which a nonlinear load power output device and a nonlinear conventional standard meter are combined with another embodiment;

4 is a waveform diagram of a sinusoidal waveform, a current outputted by the first current output terminal, and a current outputted by the second current output terminal according to an embodiment.

Detailed ways

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, but not all embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

It should be understood that in various embodiments, the non-linear load power output device may also be referred to as a non-linear load standard power source.

As shown in FIG. 1 , a non-linear load power output device 100 according to a preferred embodiment of the present invention includes: a main control unit 110, a waveform generator unit 120, and a power amplifier unit 130; the main control unit 110 and the The waveform generator unit 120 is connected, and the waveform generator unit 120 is connected to the power amplifier unit 130. The main control unit 110 is configured to generate three voltages and three currents according to the control command and divide each phase current into Two discrete digital signals are sent to the waveform generator unit 120, wherein the superposition of the waveforms corresponding to the two discrete digital signals of each phase current is a complete sine The waveform generator unit 120 is configured to receive the discrete digital signal, and convert the discrete digital signal into an analog signal, and output the analog signal to the power amplifier unit 130, where The waveform corresponding to the two analog signals of each phase current is a non-linear waveform, and the two non-linear waveform superpositions are equal to the sine wave waveform; For the amplifier unit 130 through the output terminal of said amplified analog signal.

Specifically, an output end of the main control unit 110 is connected to an input end of the waveform generator unit 120, and an output end of the waveform generator unit 120 is connected to an input end of the power amplifier unit 130.

In this embodiment, the main control unit 110 is an FPGA (Field-Programmable Gate Array), and the main control unit 110 is configured to program three-phase voltage and three-phase according to the received control command. The digital signal of current, wherein the two digital signals of each phase current are discrete signals, or non-linear signals, and the two digital signals are superimposed and the corresponding values are continuous values, which are reflected as complete sine on the waveform. Wave waveforms, for example, two digital signals superimposed or combined are corresponding to a sine wave.

The waveform generator unit 120 is a DAC (Digital to Analog Converter) for converting the digital signals into corresponding analog signals, wherein the waveforms of the two analog signals of each phase current are superimposed. The complete sinusoidal waveform, that is, the waveform corresponding to each analog signal is a non-linear waveform. Specifically, the waveform generator unit 120 outputs the digital signal to the power amplifier unit 130 according to the control instruction of the main control unit 110.

Specifically, the main control unit 110 is configured to generate two discrete digital signals based on two durations according to a control instruction, wherein the durations of the two durations are equal, and the two discrete digital signals are combined. After that, a continuous digital signal is formed, that is, a complete digital signal corresponding to each phase current waveform. Specifically, the main control unit 110 is configured to generate two discrete digital signals based on the first duration and the second duration, and the waveform generator unit 120 converts the two discrete digital signals into two analog signals, respectively. The first duration is equal to the second duration, that is, the length of time of the first duration is equal to the length of time of the second duration, and the first duration and the second duration are sequentially cycled, for example, two analog signals include An analog signal and a second analog signal, the first analog signal corresponding to the first duration, the second analog signal corresponding to the second duration, that is, the first analog signal is valid at the first duration, and the second analog signal is The value of the first analog signal corresponds to the value of the continuous digital signal; in the second duration, the value of the first analog signal is zero, and the value of the second analog signal is valid, at this time, The values of the two analog signals correspond to the values of the continuous digital signals; thus, the waveform areas corresponding to the first analog signal and the second analog signal are consecutive digital signals, respectively The complete phase of each phase current waveform is one-half, and the waveform corresponding to the first analog signal and the second analog signal is a complete waveform of each phase corresponding to the continuous digital signal.

The power amplifier unit 130 is configured to amplify the analog signal and output through the output end, that is, the power amplifier is configured to separately output a voltage and a current of the analog signal through an output end, that is, a power amplifier is used to pass The output terminal outputs a sinusoidal voltage and a current of a non-linear waveform, wherein the current outputted from each output of the current is a current of a non-linear waveform, and the current of the nonlinear waveform outputted by the two output ends of each phase current is superimposed. For complete current per phase.

The main control unit generates a current signal according to the input control command, and divides the current of each phase sine wave waveform into two discrete digital signals, and converts the digital signal of each phase current of the waveform generator unit into a corresponding nonlinear waveform simulation. The signal is output, so that the measurement of the non-linear waveform current can be performed by measuring the analog signal of one of the nonlinear waveforms through the test table; in addition, the main control unit can generate the current of the nonlinear waveform through the waveform generator unit. It is also possible to synthesize the non-linear waveforms of the two branches into the sinusoidal waveform through the trunk road, thereby realizing the measurement of the sine wave by the conventional standard table. Checking the measurement of the nonlinear wave by the test table is credible. At the same time, because the traditional standard meter measures sine waves and is standard traceable, it is easy to achieve standard traceability of nonlinear wave measurement.

In this embodiment, the nonlinear load power output device 100 divides the sinusoidal current waveform of the digital signal of each phase into two digital signals of the nonlinear waveform through the main control unit, and converts the digital signal by the waveform generator unit 120. In order to simulate the output of the current signal, the nonlinear load power output device 100 can output the current of the nonlinear waveform, or can synthesize the nonlinear waveform of the two branches into the current of the sinusoidal waveform through the trunk, and at the same time, due to the traditional standard The table is traced by the sine wave standard, so that the measured value of the sine wave waveform is verified by the traditional standard table. The test table 210 compares the measurement of the nonlinear waveform, and verifies whether the nonlinear measurement is "trustworthy".

In order to achieve a stable and accurate output of the power amplifier, in one embodiment, the non-linear load power output device 100 further includes an analog sampling unit 140 and a measurement calculation unit 150, the power amplifier unit 130 being coupled to the analog sampling unit 140, The analog sampling unit 140 is connected to the measurement calculation unit 150, and the measurement calculation unit 150 is connected to the main control unit 110. The analog sampling unit 140 is configured to perform the analog signal output by the power amplifier. Sampling, and converting the analog signal obtained by sampling into a digital signal, and transmitting the converted digital signal to the measurement calculation unit 150; the measurement calculation unit 150 is configured to perform the converted digital signal The main control unit 110 is further configured to compare the digital signal generated according to the control instruction and the digital signal measured by the measurement calculation unit 150.

Specifically, the analog sampling unit 140 is an ADC (Analog-to-Digital Converter), and the analog sampling unit 140 collects the analog signal output from the power amplifier unit 130 and converts it into a digital signal output to the measurement. The calculation unit 150 is an FPGA; for example, the analog sampling unit 140 is configured to combine the two analog signals and convert the digital signals into a digital output signal to the measurement calculation unit 150, and the measurement calculation unit 150 is used for the simulation. The unit combines the output digital signals for measurement, such that the main control unit 110 can compare the digital signals output by itself and the digital signals fed back by the measurement calculation unit 150. In this embodiment, the measurement calculation unit 150 also has the function of the standard table 230, which can be used to provide standard delivery after standard traceability.

In one embodiment, the non-linear load power output device 100 further includes an input unit for receiving a control command to transmit the control command to the main control unit 110. In this embodiment, the input unit is a human-machine interaction unit 160 for the user to input a control instruction, the human-machine interaction unit 160 sends a control instruction to the main control unit 110, and the human-machine interaction unit 160 is further configured to receive the main control unit. Feedback of the comparison result of 110, for example, the human-machine interaction unit 160 further includes a display sub-unit for displaying the comparison result.

In one embodiment, the waveform generator unit is configured to convert the three-phase digital signal into a three-phase analog signal, and wherein the signal of each phase current includes two of the analog signals and three-phase The analog signal is output to the power amplifier unit, and two of the non-linear waveforms of each phase current are superimposed to be equal to one of the complete sinusoidal waveforms.

In one embodiment, the power amplifier unit 130 has an output of three phases, wherein each phase current output includes two of the outputs, and two of the outputs of each phase are used to respectively output two of the same phase The analog signals. For example, the current of the waveform generator unit 120 has three-phase six-way output terminals, each phase current includes two output terminals, and two output terminals of each phase current are used to respectively output two complementary analog current signals. Or, the two outputs of each phase current are used to respectively output the divided two analog signals corresponding to one continuous current digital signal. The power amplifier unit 130 has three-phase six-way current input terminals, each current input end of the power amplifier is correspondingly connected with each current output end of the waveform generator unit 120; and the power amplifier unit 130 has three Phase six current output terminals, each phase comprising two current output terminals, two output ends of each phase current for respectively outputting two amplified analog signals, such that three phases a, b of power amplifier unit 130 The currents of the analog signals respectively output by c and c are I _1a , I _2a , I _1b , I _2b , I _1c and I _2c , and the voltages of the three phases a, b and c of the power amplifier unit 130 are Ua, Ub and Uc, respectively. .

In order to test the test table 210 to verify that the nonlinear measurement accuracy of the test table 210 is "trustworthy", in one embodiment, the power amplifier unit 130 is in the two of the outputs One for connecting the test table 210, one of the two outputs of the same phase of the power amplifier unit 130 is used to connect the test table 210, such that the analog sampling unit 140 and the measurement calculation unit 150 are paired with one phase. The sine wave waveform is collected and measured, and the test table 210 measures the nonlinear waveform of the analog model outputted from one of the outputs of the phase, and detects whether the nonlinear waveform measured by the test table 210 is a sinusoidal waveform of the phase. One-half of the test can detect that the accuracy of the test table 210 is "trustworthy".

In each of the above embodiments, the main control unit 110 generates a digital signal according to the input control command, and the complete current waveform corresponding to the digital signal by the waveform generator unit 120 is divided into two nonlinear waveform analog signal outputs. In this way, the measurement of the nonlinear waveform current can be realized by measuring the analog signal of one of the nonlinear waveforms by the test table 210. In addition, the main control unit 110 can generate a non-linear waveform current through the waveform generator unit 120, and can also synthesize the non-linear waveforms of the two branches into a sinusoidal waveform current through the trunk, thereby realizing the pair of traditional standard tables. The measurement of the sine wave waveform verifies whether the measurement of the nonlinear waveform by the test table 210 is reliable.

In order to achieve the detection of the accuracy of the test table 210, in one embodiment, as shown in FIG. 2, a non-linear load power and power verification device is provided, including the non-linear load power output of any of the above embodiments. The device 100 and the test circuit include a test table 210 and a conventional standard table 230. In this embodiment, a phase output of the non-linear load power output device 100 is further illustrated.

In this embodiment, the output currents of the two current outputs of the power amplifier unit 130 of the non-linear load power output device 100 are I _1a and I _2a , and the output voltage of the voltage output terminal is U _a , and the current of the phase corresponds to The waveform of the digital signal is a sine wave, and the sine wave of the digital signal is divided into two non-linear waveforms at the same time interval, that is, the waveform corresponding to I _1a and I _2a , as shown in FIG. 4, corresponding to I _1a The waveform and the waveform corresponding to I _2a are superimposed, that is, the waveform Ia of the sine wave of the digital signal.

In this embodiment, the two current output ends of the power amplifier unit 130 of the non-linear load power output device 100 are a first current output end and a second current output end, respectively, a first current output end and a second current output end period. Sexual output. The main control unit 110 is configured to generate two discrete digital signals based on the first duration t1 and the second duration t2, and the waveform generator unit 120 converts the two discrete digital signals into two analog signals, respectively. The first duration t1 is equal to the second duration t2. During the first duration t1, the value of the first current output terminal is valid, and the second current output terminal is not output. At this time, the value and the value output by the first current output terminal are The value of the signal corresponds to; at the second duration t2, the first current output terminal does not output, and the value of the second current output terminal is valid. At this time, the value output by the second stream output terminal corresponds to the value of the digital signal.

In order to measure the current of the nonlinear waveform, for example, as shown in FIG. 2, the first current output terminal I _{1a is} used for connection with the test table 210, and the second current output terminal I _{2a is} used for connection with the balanced impedance 220. The test table 210 is connected in parallel with the balanced impedance 220, and both the test table 210 and the balanced impedance 220 are connected to the other end of the non-linear load power output device 100 through the conventional standard meter 230, thereby forming a test loop.

That is, the non-linear load power output device 100 forms a loop with the test table 210, the balanced impedance 220, and the conventional standard meter 230, and the test table 210 is connected in parallel with the balanced impedance 220, and the test table 210 is connected in parallel with the balanced impedance 220 and the conventional standard table. 230 series, the test table 210 measures the current of the nonlinear waveform of the first current output, and the conventional standard meter 230 measures the combined current of the nonlinear waveform currents of the two branches in the trunk, and the synthesized current is standard. The current of the sinusoidal waveform, that is, the conventional standard meter 230 measures the "standard" current, that is, the current of the sinusoidal waveform. Thus, by comparing whether the current measured by the test table 210 is one-half of the current measured by the conventional standard meter 230, it is possible to determine whether the accuracy of the test table 210 is feasible.

In one embodiment, referring again to FIG. 2, a non-linear power measurement circuit 10 is provided, including a non-linear load power output device 100 and a test circuit. The nonlinear load power output device 100 includes a main control unit 110, a waveform generator unit 120, and a power amplifier unit 130. The main control unit 110 is connected to the waveform generator unit 120, and the waveform generator unit 120 is connected to the power amplifier unit 130. The waveform generator unit 120 has an output of a three-phase voltage and a three-phase six-way current, and each phase current includes two output terminals. The power amplifier unit 130 has an input terminal of a three-phase voltage and a three-phase six-channel current, and each input end of the power amplifier is correspondingly connected to each output end of the waveform generator unit 120, and the power amplifier unit 130 has an output of a three-phase voltage and a three-phase six-way current, and an output of each phase current includes a first current output and a second current output. The test circuit includes a test table 210, a conventional standard meter 230, a balanced impedance 220, a first resistor R1 and a second resistor R2. The first current output terminal is connected to the test table 210, and the second current output terminal is connected to the balanced impedance 220. The first resistor R1 is connected in series with the test table 210, and the second resistor R2 is connected in series with the balanced impedance 220. The first resistor R1 and the second resistor R2 are both connected to the common terminal Icom of the non-linear load power output device 100 through the conventional standard meter 230. That is to say, the first current output terminal is connected to the branch of the test table 210 and the first resistor R1, and the second current output terminal is connected to the branch where the balanced impedance 220 and the second resistor R2 are located, and the two branches are connected in parallel with the conventional standard. The table 230 is connected in series, and the two branches are connected to the common terminal Icom of the non-linear load power output device 100 through the conventional standard meter 230, and form a current loop with the non-linear load power output device 100.

Specifically, the balanced impedance 220 preferably has the same impedance as the test table 210, so that the branch where the test table 210 is located and the branch where the balanced impedance 220 is located have the same impedance, so that the test table 210 is located in the branch and The current of the branch where the balanced impedance 220 is located is in the same circuit environment, reducing the measurement error due to the impedance difference. In order to further reduce the influence of the measured meter and the balanced impedance 220 on the current, for example, the resistance value of the test table 210 is smaller than the resistance of the first resistor R1, for example, the resistance of the balanced impedance 220 is smaller than that of the first resistor R1. Resistance value. That is, the resistance of the test table 210 is less than one tenth of the resistance of the first resistor R1, or the resistance of the first resistor R1 is greater than ten times the resistance of the test table 210, and the balance impedance is 220. The resistance value is less than one tenth of the resistance of the second resistor R2; or the resistance of the second resistor R2 is greater than ten times the resistance of the balanced impedance 220, due to the resistance of the first resistor R1 and the second resistor R2 The values are the same, and are respectively larger than the resistance value of the test table 210 and the resistance value of the balanced impedance 220. Therefore, the measurement error caused by the difference between the resistance value of the test table 210 and the resistance value of the balanced impedance 220 is reduced, so that the measurement is made. More accurate.

In this embodiment, the test table 210 is used to measure the current of the nonlinear waveform outputted by the first output end, and the standard table 230 is a conventional standard table 230 for measuring the current of the main circuit, that is, the flow back. The resultant current of a standard power source. The traditional standard meter is connected in series in the trunk road, so that the traditional standard meter can measure the sine wave current, and the accuracy of the test table 210 can be detected by comparing the current of the test table 210 with the traditional standard meter. And the traditional standard table 230 is standard traceable, and the result of such comparison is "trustworthy".

In this embodiment, the test table 210 and the conventional standard table 230 are also connected to a voltage output terminal of the non-linear load power output device, and the voltage output terminal provides the voltage Ua of the standard power source for the test table 210 and the conventional standard meter.

In still other embodiments, the non-linear load power output device further includes an analog sampling unit and a measurement computing unit. The power amplifier unit is connected to the analog sampling unit, the analog sampling unit is connected to the measurement calculation unit, and the measurement calculation unit is connected to the main control unit. The measurement calculation unit in this embodiment can be regarded as another standard table for measurement of a standard power source. In this way, the nonlinear waveform measured by the test table can be compared with the waveform measured by the measurement calculation unit, thereby realizing the detection of the accuracy of the test table.

It should be understood that the traditional standard table in this paper refers to the standard table of sinusoidal traceability currently applied, and the non-linear standard table refers to the traceability of the above-mentioned nonlinear power measurement circuit (the test table in Figure 2 is a non-standard A new type of standard table after the linear standard table), which is a new standard table that has been verified to be "trustworthy" for its non-linear measurement.

In one embodiment of FIG. 3, the non-linear power measurement circuit 10 includes a non-linear load power output device 100 and a test circuit. The output end of each phase current of the nonlinear load power output device 100 includes a first current output terminal I1a and a second current output terminal I2a, and the test circuit includes a test table 210, a nonlinear standard table 230, a balanced impedance 220, and a first The resistor R1 and the second resistor R2, the first current output terminal I1a is connected to the test table 210, the second current output terminal I2a is connected to the balanced impedance 220, and the first resistor R1 and the nonlinear standard table 230 are connected in series with the test table 210. The second resistor R2 is connected in series with the balanced impedance 220. The test table 210 is sequentially connected to the common terminal Icom of the nonlinear load power output device 100 through the first resistor R1 and the nonlinear standard meter 230, and the balanced impedance 220 is passed through the second resistor R2. The common terminal Icom of the non-linear load power output device 100 is connected. That is, the first current output terminal is connected to the test table 210, the first resistor R1 and the branch of the nonlinear standard meter 230, and the second current output terminal is connected to the branch of the balance impedance 220 and the second resistor R2, two branches. The circuits are connected in parallel to the common terminal Icom of the non-linear load power output device 100, and form a current loop with the non-linear load power output device 100.

The nonlinear standard table 230 in this embodiment is a "trusted" new standard table after being measured and verified by the nonlinear power measuring circuit 10, and the nonlinear standard table 230 is connected in series to the branch where the test table 210 is located. If the measurement results of the test table 210 and the nonlinear standard table 230 are equal, it is determined whether the test table 210 is "trusted". In this way, it is no longer necessary to use the traditional standard table again, making the measurement more convenient.

It should be noted that the balanced impedance 220 in FIG. 3 should take into account the impedance of the nonlinear standard table, and the impedance of the balanced impedance 220 should be the integrated impedance of the test table 210 and the nonlinear standard table 230. For example, the impedance of the balance impedance 220 is equal to the sum of the impedances of the test table 210 and the nonlinear standard table 230.

The following is a specific embodiment:

The current loop of the nonlinear power measurement test circuit is connected according to the method shown in FIG. 2, and the dotted line frame is a non-linear load power output device, and the portion outside the dotted line frame is an external measurement component. By controlling the first current output terminal and the second current output terminal by the nonlinear load power output device, the measurement current is divided into two parts I _1a and I _1a , that is, I _1a and I _2a are respectively sent to the test table and the balance circuit. . The test waveform is shown in Figure 4. The current flowing through the test table is the I _1a waveform. The current flowing through the balanced impedance is the I _1a waveform. The traditional standard table flows through the synthesis of the two, that is, the flow on the traditional standard meter. The combined current is I _a . It can be considered that the current flowing through the conventional standard meter is a complete sine wave.

Figure 4 depicts the current waveform applied during the experiment. The time T is the period of the sine wave, t1 and t2 are the output durations of the first current output and the second current output, respectively, t is an output period, and t=t1+t2, t1=t2, control t1 and The size of t2 can control the nonlinear characteristics required by the test.

(1) The non-linear load power output device shown in FIG. 1 is characterized in that a conventional sinusoidal current of each phase is divided into complementary two parts, which are respectively output from respective terminals, wherein one of the current flows through The detected power/power meter or device is the test table for measuring the metering characteristics of the device under non-linear load conditions; and the other current is flowing through the balanced impedance.

(2) The non-linear load power output device shown in Fig. 1 is characterized in that the sine wave current is divided into two parts of higher frequency, and the frequency of the division can be changed to change the power waveform of the power/electric energy measurement test in the nonlinear working condition. Nonlinearity.

(3) The non-linear load power output device shown in FIG. 1 is characterized in that the current flowing through the conventional standard meter is still a complete sine wave, thus solving the standard transmission of the conventional standard meter to the nonlinear measurement. At the same time, it solves the "trustworthiness" problem of the accuracy traceability of the instrument under test.

(4) The non-linear load power output device shown in Fig. 1 is characterized in that the control principle of the two branch currents of each phase current is: there is only one branch output current at any time, and two branches The current is synthesized as a complete sine wave.

The technical features of the above-described embodiments may be combined in any combination. For the sake of brevity of description, all possible combinations of the various technical features in the above embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope of the present specification.

The above-described embodiments are merely illustrative of several embodiments of the present invention, and the description thereof is more specific and detailed, but is not to be construed as limiting the scope of the invention. It should be noted that a number of variations and modifications may be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, the scope of the invention should be determined by the appended claims.

Claims

A non-linear load power output device, comprising: a main control unit, a waveform generator unit and a power amplifier unit;

The main control unit is connected to the waveform generator unit, and the waveform generator unit is connected to the power amplifier unit;

The main control unit is configured to generate a three-phase voltage and a three-phase current signal according to the control instruction, and divide each phase current into two discrete digital signals, and send the discrete digital signals to the waveform generator unit. Wherein, the waveforms corresponding to the two discrete digital signals of each phase current are combined into a complete sine wave waveform;

The waveform generator unit is configured to receive the discrete digital signals, and convert the discrete digital signals into analog signals, and output the analog signals to the power amplifier unit, wherein two of each phase current The waveform corresponding to the analog signal is a non-linear waveform, and the two non-linear waveforms of the same phase current are superimposed to be equal to one complete sine wave waveform;

The power amplifier unit is configured to amplify the analog signal and output through the three voltages and six current outputs.
The non-linear load power output apparatus according to claim 1, further comprising an analog sampling unit and a measurement calculation unit, said power amplifier unit being coupled to said analog sampling unit, said analog sampling unit and said measuring Computing unit connection, the measurement calculation unit is connected to the main control unit;

The analog sampling unit is configured to sample the analog signal output by the power amplifier, convert the sampled analog signal into a digital signal, and send the converted digital signal to the measurement calculation unit ;

The measurement calculation unit is configured to measure the converted digital signal;

The main control unit is further configured to compare the digital signal generated according to the control instruction and the digital signal measured by the measurement calculation unit.
The non-linear load power output apparatus according to claim 1, further comprising an input unit for receiving a control command, and transmitting the control command to the main control unit.
The non-linear load power output apparatus according to claim 1, wherein said waveform generator unit is configured to convert said digital signals of three phases into three-phase analog voltage signals and current signals, wherein each phase The signal of the current includes two of the analog signals, and the three-phase analog signals are output to the power amplifier unit, and two of the non-linear waveforms of each phase current are superimposed to be equal to one of the sine wave waveforms.
The non-linear load power output apparatus according to claim 4, wherein said power amplifier unit has an output of three phases, and the current output of each phase includes two of said outputs, two of each phase The output is used to output two of the analog signals of the same phase, respectively.
The non-linear load power output apparatus according to claim 1, wherein one of said two output terminals of said power amplifier unit is for connecting to a test list.