CN106253776A - Generator power pick-up device based on comprehensive harmonic failure identification and delivering method - Google Patents

Abstract

The invention discloses a kind of generator power pick-up device based on comprehensive harmonic failure identification and delivering method, first Real-time Collection generator terminal voltage transformer three-phase voltage, machine end and measure level current transformer three-phase current and machine end protected level current transformer three-phase current；Calculate the fundamental phasors of generator terminal voltage transformer three-phase voltage, the machine end measurement fundamental phasors of level current transformer three-phase current, the fundamental phasors of machine end protected level current transformer three-phase current, generator power 1, generator power 2 the most respectively and measure nth harmonic component amplitude (n desirable 2,3 or 5) in level current transformer three-phase current；Use harmonic component Fault Identification criterion, if criterion function puts into and criterion meets, output generator power 2, otherwise output generator power 1.The method can effectively solve to measure the most saturated problem causing output error power of level CT, exports correct power.

Description

Generator power pick-up device based on comprehensive harmonic failure identification and delivering method

Technical field

The invention belongs to field of power, become particularly to a kind of generator power based on comprehensive harmonic failure identification Send device and delivering method.

Background technology

Conventional electric generators power transducer measures level current transformer electric current by gathering generator terminal voltage and machine end, Time division multiplier principle is utilized to produce analog quantity power signal, supply unit Distributed Control System (DCS) and steam turbine digital Electrohydraulic control system (DEH) uses.When breaking down outside unit district, the situation such as adjacent transformers sky punching time, due to fault current Big or containing factors such as aperiodic components so that Generator end is measured level current transformer current waveform and is distorted, and causes Power transducer cannot actual response electromotor current power and output error power, even more so that DEH or DCS misoperation. Feeding back according to scene, domestic fired power generating unit has occurred to cause DEH vapour owing to power transducer exports distortion during a lot of electric network fault The fast accident controlling misoperation of door, also results in the shutdown of multiple stage unit in some cases, and consequence is the most serious.

" CN201410131932 " proposes a kind of generator power delivering method based on over current fault identical criterion, should Method uses full wave Fourier algorithm, it is achieved method is simple, but there is also some an open questions: when electromotor light duty is sent out During raw fault, over current fault identical criterion sensitivity is the highest.It is the electromotor of 1.1～1.3 times owing to crossing stream definite value and typically adjusting Rated current, fault current need to just use protected level current transformer electric current to count more than power calculation electric current during this definite value Calculate.When breaking down under electromotor light duty and fault component contains aperiodic component, owing to fault current is little, Protected level current transformer electric current was not more than stream definite value threshold, the most then cannot realize by machine potential transformer three-phase voltage Export with the machine end protected level calculated power of current transformer three-phase current, and measure grade current transformer because of by aperiodic Component factor impact and saturated, cause current waveform to distort, resulting device output error power.

Summary of the invention

The purpose of the present invention, is to provide a kind of generator power pick-up device based on comprehensive harmonic failure identification and change Delivery method, can effectively solve to measure the most saturated problem causing output error power of level CT, export correct power.

For reaching above-mentioned purpose, the solution of the present invention is:

A kind of generator power pick-up device based on comprehensive harmonic failure identification, including:

Detector unit, is used for detecting generator terminal voltage transformer three-phase voltage, machine end measurement level current transformer three Phase current and protected level current transformer three-phase current；

Computing unit, for the voltage and current obtained according to described detector unit, calculates generator terminal voltage mutual inductance The fundamental phasors of device three-phase voltage, machine end measure fundamental phasors and the protected level current transformer of level current transformer three-phase current The fundamental phasors of three-phase current；Calculating power 1 and power 2, wherein power 1 is by the first-harmonic of machine potential transformer three-phase voltage Phasor and machine end are measured the fundamental phasors of level current transformer three-phase current and are calculated, and power 2 is by machine potential transformer The fundamental phasors of three-phase voltage and the fundamental phasors of machine end protected level current transformer three-phase current are calculated；Calculate by machine end Measure nth harmonic component amplitude, wherein n desirable 2,3 or 5 in level current transformer three-phase current；And

Judging unit, for comparing described harmonic component amplitude with harmonic component definite value threshold, when machine end measures level electricity In current transformer three-phase current, arbitrary phase nth harmonic component amplitude is more than corresponding harmonic component definite value threshold, then output generator Power 2, otherwise output generator power 1.

A kind of generator power delivering method based on comprehensive harmonic failure identification, comprises the steps:

Step 1: Real-time Collection generator terminal voltage transformer three-phase voltage, machine end measure level current transformer three-phase electricity Stream and machine end protected level current transformer three-phase current；

Step 2: use Fourier algorithm to calculate the fundamental phasors of generator terminal voltage transformer three-phase voltage, machine end is surveyed The fundamental phasors of magnitude current transformer three-phase current and the fundamental phasors of machine end protected level current transformer three-phase current；

Step 3: calculate power 1 and power 2；Described power 1 is by the first-harmonic phase of machine potential transformer three-phase voltage Amount and machine end are measured the fundamental phasors of level current transformer three-phase current and are calculated；Described power 2 is mutual by set end voltage The fundamental phasors of sensor three-phase voltage and the fundamental phasors of machine end protected level current transformer three-phase current are calculated；

Step 4: computer terminal measures nth harmonic component amplitude, wherein n desirable 2,3 in level current transformer three-phase current Or 5；

Step 5: use harmonic component Fault Identification criterion, output 2 when criterion meets, otherwise output 1.

In above-mentioned steps 3, power 1 uses equation below to calculate:

$P=\mathrm{Re}({\stackrel{\·}{U}}_{ga}{{\stackrel{\·}{I}}_{ma}}^{*}+{\stackrel{\·}{U}}_{gb}{{\stackrel{\·}{I}}_{mb}}^{*}+{\stackrel{\·}{U}}_{gc}{{\stackrel{\·}{I}}_{mc}}^{*}),Q_1=Im({\stackrel{\·}{U}}_{ga}{{\stackrel{\·}{I}}_{ma}}^{*}+{\stackrel{\·}{U}}_{gb}{{\stackrel{\·}{I}}_{mb}}^{*}+{\stackrel{\·}{U}}_{gc}{{\stackrel{\·}{I}}_{mc}}^{*})$

Wherein, P₁It is the active power in power 1, Q₁Being the reactive power in power 1, Re represents the real part taking phasor, Im Represent the imaginary part taking phasor,It is respectively the fundamental phasors of generator terminal voltage transformer three-phase voltage,It is respectively machine end and measures the fundamental phasors of level current transformer three-phase currentConjugation Plural number.

In above-mentioned steps 3, power 2 uses equation below to calculate:

$P_2=\mathrm{Re}({\stackrel{\·}{U}}_{ga}{{\stackrel{\·}{I}}_{pa}}^{*}+{\stackrel{\·}{U}}_{gb}{{\stackrel{\·}{I}}_{pb}}^{*}+{\stackrel{\·}{U}}_{gc}{{\stackrel{\·}{I}}_{pc}}^{*}),Q_2=Im({\stackrel{\·}{U}}_{ga}{{\stackrel{\·}{I}}_{pa}}^{*}+{\stackrel{\·}{U}}_{gb}{{\stackrel{\·}{I}}_{pb}}^{*}+{\stackrel{\·}{U}}_{gc}{{\stackrel{\·}{I}}_{pc}}^{*})$

Wherein, P₂It is the active power in power 2, Q₂Being the reactive power in power 2, Re represents the real part taking phasor, Im Represent the imaginary part taking phasor,It is respectively the fundamental phasors of generator terminal voltage transformer three-phase voltage,It is respectively the fundamental phasors of machine end protected level current transformer three-phase currentConjugate complex Number.

Above-mentioned steps 5, it is as follows that harmonic component Fault Identification sentences formula:

Wherein,Level current transformer three-phase current nth harmonic component amplitude, I is measured for machine end_{n_Set}For nth harmonic Component definite value threshold.

After using such scheme, the present invention uses harmonic component Fault Identification criterion, improves generator failure identification and sentences According to sensitivity, can effectively solve to measure the most saturated problem causing output error power of level CT.

Accompanying drawing explanation

Fig. 1 is the flow chart of the present invention.

Detailed description of the invention

Below with reference to accompanying drawing, technical scheme is described in detail.

The present invention provides a kind of generator power pick-up device based on comprehensive harmonic failure identification, including detector unit, Computing unit and judging unit, wherein, detector unit is used for detecting generator terminal voltage transformer three-phase voltage, machine end is measured Level current transformer three-phase current and machine end protected level current transformer three-phase current.

Described computing unit, for the voltage and current obtained according to described detector unit, calculates generator terminal voltage Fundamental phasors and the protected level electric current of the fundamental phasors of transformer three-phase voltage, machine end measurement level current transformer three-phase current are mutual The fundamental phasors of sensor three-phase current；Calculating power 1 and power 2, wherein power 1 is by machine potential transformer three-phase voltage Fundamental phasors and machine end are measured the fundamental phasors of level current transformer three-phase current and are calculated, and power 2 is mutual by set end voltage The fundamental phasors of sensor three-phase voltage and the fundamental phasors of machine end protected level current transformer three-phase current are calculated；Calculate by Machine end measures nth harmonic component amplitude, wherein n desirable 2,3 or 5 in level current transformer three-phase current.

Described judging unit is for comparing described harmonic component amplitude with harmonic component definite value threshold, when machine end measures level In current transformer three-phase current, arbitrary phase nth harmonic component amplitude is more than corresponding harmonic component definite value threshold, then export generating Acc power 2, otherwise output generator power 1.

Based on above pick-up device, as it is shown in figure 1, the present invention also provides for a kind of generating based on comprehensive harmonic failure identification Acc power delivering method, comprises the steps:

Step 1, Real-time Collection generator terminal voltage transformer three-phase voltage, machine end measure level current transformer three-phase electricity Stream and machine end protected level current transformer three-phase current；

Step 2, uses Fourier algorithm to calculate the fundamental phasors of generator terminal voltage transformer three-phase voltageMachine end measures the fundamental phasors of level current transformer three-phase currentWith machine end protected level The fundamental phasors of current transformer three-phase current

Step 3, fundamental phasors and machine end according to machine potential transformer three-phase voltage measure level current transformer three-phase The fundamental phasors of electric current, according to below equation calculating power 1:

$P_1=\mathrm{Re}({\stackrel{\·}{U}}_{ga}{{\stackrel{\·}{I}}_{ma}}^{*}+{\stackrel{\·}{U}}_{gb}{{\stackrel{\·}{I}}_{mb}}^{*}+{\stackrel{\·}{U}}_{gc}{{\stackrel{\·}{I}}_{mc}}^{*}),Q_1=Im({\stackrel{\·}{U}}_{ga}{{\stackrel{\·}{I}}_{ma}}^{*}+{\stackrel{\·}{U}}_{gb}{{\stackrel{\·}{I}}_{mb}}^{*}+{\stackrel{\·}{U}}_{gc}{{\stackrel{\·}{I}}_{mc}}^{*})$

Wherein, P₁It is the active power in power 1, Q₁Being the reactive power in power 1, Re represents the real part taking phasor, Im Represent the imaginary part taking phasor,It is respectivelyConjugate complex number.

Fundamental phasors according to machine potential transformer three-phase voltage and machine end protected level current transformer three-phase current Fundamental phasors, according to below equation calculating power 2:

$P_2=\mathrm{Re}({\stackrel{\·}{U}}_{ga}{{\stackrel{\·}{I}}_{pa}}^{*}+{\stackrel{\·}{U}}_{gb}{{\stackrel{\·}{I}}_{pb}}^{*}+{\stackrel{\·}{U}}_{gc}{{\stackrel{\·}{I}}_{pc}}^{*}),Q_2=Im({\stackrel{\·}{U}}_{ga}{{\stackrel{\·}{I}}_{pa}}^{*}+{\stackrel{\·}{U}}_{gb}{{\stackrel{\·}{I}}_{pb}}^{*}+{\stackrel{\·}{U}}_{gc}{{\stackrel{\·}{I}}_{pc}}^{*})$

Wherein, P₂It is the active power in power 2, Q₂Being the reactive power in power 2, Re represents the real part taking phasor, Im Represent the imaginary part taking phasor,It is respectivelyConjugate complex number.

Step 4, computer terminal measures nth harmonic component amplitude in level current transformer three-phase currentWherein n is desirable 2,3 or 5；

Step 5, uses harmonic component Fault Identification criterion, and harmonic component Fault Identification criterion formula is:

Wherein, subscriptDesirable A, B or C, represent A, B, C three-phase respectively,Level current transformer three-phase is measured for machine end Nth harmonic component amplitude in electric current, wherein n desirable 2,3 or 5；I_{n_Set}For harmonic component definite value threshold.

Above example is only the technological thought that the present invention is described, it is impossible to limit protection scope of the present invention with this, every The technological thought proposed according to the present invention, any change done on the basis of technical scheme, each fall within scope Within.

Claims (5)

1. a generator power pick-up device based on comprehensive harmonic failure identification, it is characterised in that including:

Detector unit, is used for detecting generator terminal voltage transformer three-phase voltage, machine end measurement level current transformer three-phase electricity Stream and protected level current transformer three-phase current；

Computing unit, for the voltage and current obtained according to described detector unit, calculates generator terminal voltage transformer three The fundamental phasors of phase voltage, machine end measure fundamental phasors and the protected level current transformer three-phase of level current transformer three-phase current The fundamental phasors of electric current；Calculating power 1 and power 2, wherein power 1 is by the fundamental phasors of machine potential transformer three-phase voltage The fundamental phasors measuring level current transformer three-phase current with machine end is calculated, and power 2 is by machine potential transformer three-phase The fundamental phasors of voltage and the fundamental phasors of machine end protected level current transformer three-phase current are calculated；Calculate and measured by machine end Nth harmonic component amplitude, wherein n desirable 2,3 or 5 in level current transformer three-phase current；And

Judging unit, for comparing described harmonic component amplitude with harmonic component definite value threshold, when machine end measurement level electric current is mutual In sensor three-phase current, arbitrary phase nth harmonic component amplitude is more than corresponding harmonic component definite value threshold, then output generator power 2, otherwise output generator power 1.

2. a generator power delivering method based on comprehensive harmonic failure identification, it is characterised in that employing following steps:

Step 1: Real-time Collection generator terminal voltage transformer three-phase voltage, machine end measure level current transformer three-phase current and Machine end protected level current transformer three-phase current；

Step 2: use Fourier algorithm to calculate the fundamental phasors of generator terminal voltage transformer three-phase voltage, machine end measures level The fundamental phasors of current transformer three-phase current and the fundamental phasors of machine end protected level current transformer three-phase current；

Step 3: calculate power 1 and power 2；Described power 1 be the fundamental phasors by machine potential transformer three-phase voltage and Machine end is measured the fundamental phasors of level current transformer three-phase current and is calculated；Described power 2 is by machine potential transformer The fundamental phasors of three-phase voltage and the fundamental phasors of machine end protected level current transformer three-phase current are calculated；

Step 4: computer terminal measures nth harmonic component amplitude, wherein n desirable 2,3 or 5 in level current transformer three-phase current；

Step 5: use harmonic component Fault Identification criterion, output 2 when criterion meets, otherwise output 1.

3. generator power delivering method based on comprehensive harmonic failure identification as claimed in claim 2, it is characterised in that: institute Stating in step 3, power 1 uses equation below to calculate:

$P_1=\mathrm{Re}({\stackrel{\·}{U}}_{ga}{{\stackrel{\·}{I}}_{ma}}^{*}+{\stackrel{\·}{U}}_{gb}{{\stackrel{\·}{I}}_{mb}}^{*}+{\stackrel{\·}{U}}_{gc}{{\stackrel{\·}{I}}_{mc}}^{*}),Q_1=\mathrm{Im}({\stackrel{\·}{U}}_{ga}{{\stackrel{\·}{I}}_{ma}}^{*}+{\stackrel{\·}{U}}_{gb}{{\stackrel{\·}{I}}_{mb}}^{*}+{\stackrel{\·}{U}}_{gc}{{\stackrel{\·}{I}}_{mc}}^{*})$

Wherein, P₁For the active power in power 1, Q₁For the reactive power in power 1, Re represents the real part taking phasor, Im table Show the imaginary part taking phasor,It is respectively the fundamental phasors of generator terminal voltage transformer three-phase voltage,It is respectively Generator end and measures the fundamental phasors of level current transformer three-phase current, It is respectively machine end and measures the conjugate complex number of level current transformer three-phase current fundamental phasors.

4. generator power delivering method based on comprehensive harmonic failure identification as claimed in claim 2, it is characterised in that: institute Stating in step 3, power 2 uses equation below to calculate:

$P_2=\mathrm{Re}({\stackrel{\·}{U}}_{ga}{{\stackrel{\·}{I}}_{pa}}^{*}+{\stackrel{\·}{U}}_{gb}{{\stackrel{\·}{I}}_{pb}}^{*}+{\stackrel{\·}{U}}_{gc}{{\stackrel{\·}{I}}_{pc}}^{*}),Q_2=\mathrm{Im}({\stackrel{\·}{U}}_{ga}{{\stackrel{\·}{I}}_{pa}}^{*}+{\stackrel{\·}{U}}_{gb}{{\stackrel{\·}{I}}_{pb}}^{*}+{\stackrel{\·}{U}}_{gc}{{\stackrel{\·}{I}}_{pc}}^{*})$

Wherein, P₂For the active power in power 2, Q₂For the reactive power in power 2, Re represents the real part taking phasor, and Im represents Take the imaginary part of phasor,It is respectively the fundamental phasors of generator terminal voltage transformer three-phase voltage,It is respectively the fundamental phasors of Generator end protected level current transformer three-phase current, It is respectively the conjugate complex number of machine end protected level current transformer three-phase current fundamental phasors.

5. generator power delivering method based on comprehensive harmonic failure identification as claimed in claim 2, it is characterised in that: institute Stating in step 5, harmonic component Fault Identification criterion formula is:

Wherein, subscriptDesirable A, B or C, represent A, B, C three-phase respectively,Level current transformer three-phase current is measured for machine end Middle nth harmonic component amplitude, wherein n desirable 2,3 or 5；I_{n_Set}For harmonic component definite value threshold.