CN101806843A - Magnetic induction waveform control device and method for iron loss test probe - Google Patents

Abstract

The invention relates to the technical field of silicon steel sheet iron core loss measurement, in particular to a magnetic induction waveform control device and a magnetic induction waveform control method for a test probe in an iron loss tester. The magnetic induction waveform control device comprises a test probe, a microcontroller, a digital to analog converter, a power amplifying circuit, an analog to digital converter and a signal processing circuit, and is characterized in that: the microcontroller is connected with the digital to analog converter and the analog to digital converter respectively; the test probe is positioned between the power amplifying circuit and the signal processing circuit, and consists of a primary coil and a secondary coil, wherein the primary coil is serially connected between the power amplifier and analog ground, and the secondary coil is serially connected between the signal processing circuit and the analog ground; and the working procedure of the microcontroller adopts C language programming. The magnetic induction waveform control device and the magnetic induction waveform control method have the advantages of simple structure and convenient use, and effectively guarantee that the magnetic induction is sinusoidal.

Description

Iron loss test probe magnetic induction waveform control device and control method thereof

Technical field

The present invention relates to a kind of silicon steel plate core loss measurement technical field, particularly relate to test probe magnetic induction waveform control device and control method thereof in a kind of iron loss tester.

Background technology

On the engineering, under magnetic induction waveform is sinusoidal wave condition, be the important benchmark that 1.7T and the core loss value when not having orientation magnetic induction density and being 1.5T are judged as magnetic property with orientation magnetic induction density.Carry out in the process of iron loss test, because magnetization curve is non-linear, distortion can appear in magnetic induction waveform.Therefore, how to guarantee effectively that magnetic induction density is that sine is the key link of iron loss test.

Summary of the invention

The object of the present invention is to provide a kind of simple in structure, easy to use, guarantee that magnetic induction density is sinusoidal Waveform controller effectively.

The objective of the invention is to adopt such technical solution to realize: it comprises test probe, microcontroller, digital to analog converter, power amplification circuit, analog to digital converter and signal processing circuit, it is characterized in that described microcontroller is connected with the analog to digital converter device with digital to analog converter respectively, described test probe is between power amplification circuit and signal processing circuit, described test test probe is made of primary coil and secondary coil, wherein primary coil is serially connected between power amplifier and the simulation ground, secondary coil is serially connected in signal processing circuit and joins and simulate between the ground, and the working routine of described microcontroller adopts the establishment of C language.

Because apparatus of the present invention have adopted microcontroller to be connected with the analog to digital converter device with digital to analog converter respectively, test probe is connected between power amplification circuit and the signal processing circuit, the test test probe is made of primary coil and secondary coil, wherein primary coil is serially connected between power amplifier and the simulation ground, secondary coil is serially connected in signal processing circuit and joins and simulate circuit structure between the ground, it can understand magnetic induction density amplitude Size Error and magnetic induction waveform coefficient error in real time, and the working routine by microcontroller, the error amount utilization of overshoot value scope is adjusted waveform based on the digital feedback method; Until error amount in specialized range, thereby guarantee that effectively magnetic induction density is sinusoidal, improved the efficient and the quality of test.

Description of drawings

Fig. 1 is a structural principle synoptic diagram of the present invention

Fig. 2 is a working routine process flow diagram of the present invention

The drawing reference numeral explanation: 1-test probe, 2-are simulated ground, the 3-primary coil, and 4-secondary coil, 5-are simulated ground, 6-power amplification circuit, 7-signal processing circuit, 8-digital to analog converter, 9-analog to digital converter, 10-microcontroller.

Embodiment

With reference to Fig. 1: the present invention includes test probe 1, microcontroller 10, digital to analog converter 8, power amplification circuit 6, analog to digital converter 9 and signal processing circuit 7, described microcontroller 10 is connected with analog to digital converter 9 with digital to analog converter 8 respectively, described test probe 1 is between power amplification circuit 6 and signal processing circuit 7, described test test probe 1 is made of parts such as primary coil 3 and secondary coils 4, described primary coil 3 is serially connected between power amplifier 6 and the simulation ground 2, described secondary coil string 4 be connected on signal processing circuit 7 join with simulate between 5.Described microcontroller 10, digital to analog converter 8, analog to digital converter 9, test probe 1, power amplification circuit 6 are buied by market, and the working routine of microcontroller 10 adopts the establishment of C language.

The concrete steps of apparatus of the present invention test probe magnetic induction waveform control method are as follows:

1. parameter is set, comprises that the siliconized plate sample cross amasss A, magnetic induction density amplitude Bm;

2. to test probe primary coil 3 delivered waveform signals;

3. the voltage signal of collecting test probe secondary coil 4;

4. the voltage signal that 3. obtains according to step, calculated magnetic induction intensity amplitude Bm Size Error and magnetic induction waveform coefficient error;

5. judge that the Size Error of magnetic induction density and form factor error are whether in the setting scope; Error amount in the setting scope, EOP (end of program) then; If error amount overshoot value scope, then return step and 2. carry out waveform adjustment based on the digital feedback method; Until error amount in specialized range.

Described magnetic induction density amplitude Bm and magnetic induction waveform coefficient relation meet following computing formula:

$\mathrm{Bm}=\frac{U_2}{4.444f{N}_{2}A}$

$K_F=\frac{V_{\mathrm{rms}}}{V_{\mathrm{avg}}}=\frac{\sqrt{\frac{1}{T}\underset{0}{\overset{T}{\∫}}{f}^2\left(t\right)\mathrm{dt}}}{\frac{1}{T}\underset{0}{\overset{T}{\∫}}\left|f\left(t\right)\right|\mathrm{dt}}=\frac{\mathrm{\π}}{2\sqrt{2}}\≈1.111$

In the formula, Bm is the magnetic induction density amplitude, U ₂Be secondary coil 4 induced voltages, f is the frequency that digital to analog converter 8 produces waveform for the field power supply frequency, N ₂Be secondary coil 4 numbers of turn, A is that the siliconized plate sample cross is long-pending; K _FBe form factor, V _RmsBe voltage effective value, V _AvgBe average voltage, T is the field power supply cycle;

The error range of described error amount and setting is in ± 0.1%;

Described Waveform regulating method based on the digital feedback method is as follows:

A. amplitude adjustment

If M (i), U ₂(i) be the waveforms amplitude and the inductive voltage value of the i time iteration respectively, the i+1 time iteration waveforms amplitude M (i+1) determined by following formula:

M(i+1)＝(U _ref-U ₂(i))/K+M(i)

In the formula, U _RefBe the induced voltage effective value of default Bm correspondence, K is a constant;

B. form factor adjustment

The waveform adjustment process is as follows:

(1) digital to analog converter 8 output sinusoidal voltage U ₁

(2) measure secondary coil 4 induced voltage U ₂

(3) the i+1 time iteration voltage U ₁(i+1) waveform is determined by following formula:

U ₁(i+1)＝U ₁(i)-K _FF(U ₂(i)-U _ref)

In the formula, K _FFBe feedback factor, value between 0～1 generally gets 0.5.

Claims (4)

1. test probe magnetic induction waveform control device in the iron loss tester, comprise test probe, microcontroller, digital to analog converter, power amplification circuit, analog to digital converter and signal processing circuit, it is characterized in that described microcontroller is connected with the analog to digital converter device with digital to analog converter respectively, described test probe is between power amplification circuit and signal processing circuit, described test test probe is made of primary coil and secondary coil, wherein primary coil is serially connected between power amplifier and the simulation ground, secondary coil is serially connected in signal processing circuit and joins and simulate between the ground, and the working routine of described microcontroller adopts the establishment of C language.

2. test probe magnetic induction waveform control method in the iron loss tester is characterized in that adopting following steps to realize:

1. parameter is set, comprises that the siliconized plate sample cross amasss A, magnetic induction density amplitude Bm;

2. to test probe primary coil delivered waveform signal;

3. the voltage signal of collecting test probe secondary coil 4;

4. the voltage signal that 3. obtains according to step, calculated magnetic induction intensity amplitude Size Error and magnetic induction waveform coefficient error;

5. judge that the Size Error of magnetic induction density and form factor error are whether in the setting scope; Error amount in the setting scope, EOP (end of program) then; If error amount overshoot value scope, then return step and 2. carry out waveform adjustment based on the digital feedback method; Until error amount in specialized range.

3. test probe magnetic induction waveform control method in the iron loss tester according to claim 2, described magnetic induction density amplitude Bm and the magnetic induction waveform coefficient relation that it is characterized in that meets following computing formula:

$\mathrm{Bm}=\frac{U_2}{4.444f{N}_{2}A}$

$K_F=\frac{V_{\mathrm{rms}}}{V_{\mathrm{avg}}}=\frac{\sqrt{\frac{1}{T}\underset{0}{\overset{T}{\∫}}{f}^2\left(t\right)\mathrm{dt}}}{\frac{1}{T}\underset{0}{\overset{T}{\∫}}\left|f\left(t\right)\right|\mathrm{dt}}=\frac{\mathrm{\π}}{2\sqrt{2}}\≈1.111$

In the formula, Bm is the magnetic induction density amplitude, U ₂Be secondary coil 4 induced voltages, f is the frequency that digital to analog converter 8 produces waveform for the field power supply frequency, N ₂Be secondary coil 4 numbers of turn, A is that the siliconized plate sample cross is long-pending; K _FBe form factor, V _RmsBe voltage effective value, V _AvgBe average voltage, T is the field power supply cycle;

The error range of described error amount and setting is in ± 0.1%.

4. test probe magnetic induction waveform control method in the iron loss tester according to claim 2 is characterized in that described Waveform regulating method based on the digital feedback method is as follows:

A. amplitude adjustment

If M (i), U ₂(i) be the waveforms amplitude and the inductive voltage value of the i time iteration respectively, the i+1 time iteration waveforms amplitude M (i+1) determined by following formula:

M(i+1)＝(U _ref-U ₂(i))/K+M(i)

In the formula, U _RefBe the induced voltage effective value of default Bm correspondence, K is a constant;

B. form factor adjustment

The waveform adjustment process is as follows:

(1) digital to analog converter 8 output sinusoidal voltage U ₁

(2) measure secondary coil 4 induced voltage U ₂

(3) the i+1 time iteration voltage U ₁(i+1) waveform is determined by following formula:

U ₁(i+1)＝U ₁(i)-K _FF(U ₂(i)-U _ref)

In the formula, K _FFBe feedback factor, value between 0～1 generally gets 0.5.

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