CN117293910B

CN117293910B - Power supply quality regulation and control method and system for low-voltage power generation vehicle

Info

Publication number: CN117293910B
Application number: CN202311587785.2A
Authority: CN
Inventors: 李志杰; 仇炜; 奚邦根; 邵寿甲恒; 何世麟; 柯已悦
Original assignee: Zhuhai Power Supply Bureau of Guangdong Power Grid Co Ltd
Current assignee: Zhuhai Power Supply Bureau of Guangdong Power Grid Co Ltd
Priority date: 2023-11-27
Filing date: 2023-11-27
Publication date: 2024-03-19
Anticipated expiration: 2043-11-27
Also published as: CN117293910A

Abstract

The invention discloses a method and a system for regulating and controlling the power supply quality of a low-voltage power generation vehicle, which relate to the technical field of power generation vehicle grid connection, respond to a received power supply quality regulation and control request, acquire first working condition data of a seamless grid-connected and grid-disconnected device, acquire second working condition data of the seamless grid-connected and grid-disconnected device according to a preset period according to the first working condition data and a preset working condition data threshold, judge whether a phase angle difference of the second working condition data is in a preset switching-on interval, input the second working condition data into a preset deviation function to generate a deviation value when the phase angle difference is in the switching-on interval, control a power generation vehicle grid-connected switch of the seamless grid-connected and grid-disconnected device to switch on and acquire third working condition data of the seamless grid-connected and grid-disconnected device according to the deviation value and preset reference deviation value, and control a remote grid-connected detection switch of the seamless grid-connected and grid-disconnected low-connected total switch of the grid-connected and grid-connected low-voltage total switch according to the third working condition data. The technical problems that a user has a power failure for a certain time and the power supply reliability is reduced when the low-voltage power generation vehicle is in grid-connected power supply operation are solved.

Description

Power supply quality regulation and control method and system for low-voltage power generation vehicle

Technical Field

The invention relates to the technical field of grid connection of power generation vehicles, in particular to a method and a system for regulating and controlling the power supply quality of a low-voltage power generation vehicle.

Background

With the continuous upgrading of a power system, a 10kV distribution line and equipment become important components of a power grid in China, when a large-area region is suddenly powered off due to a certain reason, and a fault can not be rapidly repaired in a short time, the power can not be supplied for a long time, and a low-voltage power generation vehicle is used as a common standby power generation device.

At present, when the low-voltage power generation vehicle is in grid-connected power supply operation, a power failure switching method is often adopted, but the method can cause power failure of a user for a certain time and times, and the power supply reliability is reduced.

Disclosure of Invention

The invention provides a method and a system for regulating and controlling the power supply quality of a low-voltage power generation vehicle, which solve the technical problems that at present, when the low-voltage power generation vehicle is in grid-connected power supply operation, a power failure switching method is often adopted, but the method can cause power failure of a user for a certain time and times, and the power supply reliability is reduced.

The invention provides a power supply quality regulation method for a low-voltage power generation vehicle, which is applied to a seamless off-grid device and comprises the following steps:

Responding to the received power supply quality regulation request, and acquiring first working condition data of the seamless off-grid device;

comparing the first working condition data with an associated preset working condition data threshold value, and acquiring second working condition data of the seamless off-grid device according to a preset period and a first comparison result;

judging whether the phase angle difference of the second working condition data is in a preset closing interval or not;

when the phase angle difference is in the closing interval, inputting the second working condition data into a preset deviation function to generate a corresponding deviation value;

comparing the deviation value with a preset reference deviation value, and controlling a generator car grid-connected switch of the seamless grid-connected and off-grid device to be switched on according to a second comparison result and acquiring third working condition data of the seamless grid-connected and off-grid device;

and controlling the remote grid-connected detection switch of the seamless grid-connected and off-grid device to be switched on and the low-voltage main switch of the transformer area to be switched off according to the third working condition data.

Optionally, the first working condition data includes a generator car voltage, a network side system voltage, a generator car frequency and a network side system frequency, the working condition data threshold includes a voltage deviation threshold and a frequency deviation threshold, the step of comparing the first working condition data with an associated preset working condition data threshold and obtaining the second working condition data of the seamless parallel-off-network device according to a first comparison result and a preset period includes:

Performing difference processing on the power generation vehicle voltage and the network side system voltage to generate a first difference value;

performing difference processing on the frequency of the power generation vehicle and the frequency of the network side system to generate a second difference value;

respectively calculating a first absolute value of the first difference value and a second absolute value of the second difference value;

judging whether the first absolute value is smaller than or equal to the voltage deviation threshold;

if the first absolute value is larger than the voltage deviation threshold, performing first pulse adjustment on the seamless parallel-to-separate device according to the first difference value, and jumping to execute the step of acquiring the first working condition data of the seamless parallel-to-separate device;

if the first absolute value is smaller than or equal to the voltage deviation threshold, judging whether the second absolute value is smaller than or equal to the frequency deviation threshold;

if the second absolute value is larger than the frequency deviation threshold value, performing second pulse adjustment on the seamless parallel-to-separate device according to the second difference value, and jumping to execute the step of acquiring the first working condition data of the seamless parallel-to-separate device;

and if the second absolute value is smaller than or equal to the frequency deviation threshold value, acquiring second working condition data of the seamless off-grid device according to a preset period.

Optionally, the bias function is specifically:

；

wherein,for a leading closing phase angle leading 360 degrees point +.>To calculate the point i slip angular frequency,time for switching-on signal to switch-off of the circuit breaker contacts, +.>For slip angular acceleration +.>For calculating the point i angle value,/>For calculating the angle value of point i-1, < >>For the time interval of two calculation points, +.>For deviation value, +.>For calculating the slip angular frequency of the points i-n, i is the number of the calculated point, n is the number of the calculated point preceding the calculated point i,/and>to calculate the point i slip angle, +.>To calculate the angle difference of point i, +.>Is the spot time interval.

Optionally, the step of comparing the deviation value with a preset reference deviation value, and controlling the grid-connected switch of the seamless grid-connected/off-grid device to switch on and obtain third working condition data of the seamless grid-connected/off-grid device according to a second comparison result includes:

judging whether the deviation value is smaller than or equal to a preset reference deviation value;

if the deviation value is larger than the reference deviation value, jumping to the step of acquiring second working condition data of the seamless off-grid device according to a preset period and the first comparison result;

and if the deviation value is smaller than or equal to the reference deviation value, controlling a grid-connected switch of the power generation vehicle of the seamless grid-connected and off-grid device to be switched on and acquiring third working condition data of the seamless grid-connected and off-grid device.

Optionally, the third working condition data includes power generation vehicle output power, network side system power, remote grid-connected detection switch running current converted power and power generation vehicle nominal power, and the step of controlling the remote grid-connected detection switch of the seamless parallel-to-off network device to switch on and the station low-voltage main switch to switch off according to the third working condition data includes:

performing difference processing on the network side system power and the power generation vehicle output power to generate a third difference value and calculating a third absolute value of the third difference value;

multiplying the nominal power of the generating vehicle with a preset power threshold value to generate a first multiplication value;

judging whether the third absolute value is smaller than the converted power of the operating current of the telemechanical grid-connected detection switch;

if the third absolute value is greater than or equal to the converted power of the running current of the telemechanical grid-connected detection switch, jumping to the step of acquiring third working condition data of the seamless grid-connected and off-grid device;

if the third absolute value is smaller than the remote grid-connected detection switch operation current converted power, judging whether the remote grid-connected detection switch operation current converted power is smaller than the first multiplication value or not;

if the converted power of the running current of the telemechanical grid-connected detection switch is larger than or equal to the first multiplication value, jumping to the step of acquiring the third working condition data of the seamless grid-connected and off-grid device;

And if the converted power of the running current of the telemechanical grid-connected detection switch is smaller than the first multiplication value, controlling the telemechanical grid-connected detection switch of the seamless grid-connected device to be switched on and the low-voltage main switch of the station area to be switched off.

Optionally, the method further comprises:

and when the phase angle difference is not in the closing interval, jumping to the step of acquiring second working condition data of the seamless off-grid device according to a preset period according to a first comparison result.

Optionally, the method further comprises:

responding to the received off-grid request, and acquiring the voltage data of the power generation vehicle and the voltage data of the grid-side system of the seamless off-grid device at the current moment;

and when the voltage data of the power generation vehicle is the same as the voltage data of the network side system, controlling the remote grid-connected detection switch and the low-voltage main switch of the platform area to be switched on and controlling the power generation vehicle grid-connected switch to be switched off.

The invention provides a power supply quality control system of a low-voltage power generation vehicle, which is applied to a seamless off-grid device and comprises the following components:

the first acquisition module is used for responding to the received power supply quality regulation and control request and acquiring first working condition data of the seamless off-grid device;

the first control module is used for comparing the first working condition data with an associated preset working condition data threshold value, and acquiring second working condition data of the seamless off-grid device according to a preset period and a first comparison result;

The first analysis module is used for judging whether the phase angle difference of the second working condition data is in a preset closing interval or not;

the second analysis module is used for inputting the second working condition data into a preset deviation function when the phase angle difference is in the closing interval, and generating a corresponding deviation value;

the second control module is used for comparing the deviation value with a preset reference deviation value, controlling the grid-connected switch of the seamless grid-connected and off-grid device to be switched on according to a second comparison result, and acquiring third working condition data of the seamless grid-connected and off-grid device;

and the third control module is used for controlling the remote grid-connected detection switch of the seamless grid-connected and off-grid device to be switched on and the low-voltage main switch of the transformer area to be switched off according to the third working condition data.

Optionally, the second control module includes:

the first analysis submodule is used for judging whether the deviation value is smaller than or equal to a preset reference deviation value;

the first control sub-module is used for jumping to the step of acquiring the second working condition data of the seamless off-grid device according to a preset period and the first comparison result if the deviation value is larger than the reference deviation value;

and the second control sub-module is used for controlling the grid-connected switch of the seamless grid-connected and off-grid device to be switched on and acquiring third working condition data of the seamless grid-connected and off-grid device if the deviation value is smaller than or equal to the reference deviation value.

Optionally, the third working condition data includes power generation vehicle output power, network side system power, remote grid-connected detection switch running current converted power and power generation vehicle nominal power, and the third control module includes:

the third difference value submodule is used for carrying out difference value processing on the network side system power and the power generation vehicle output power, generating a third difference value and calculating a third absolute value of the third difference value;

the first multiplication sub-module is used for carrying out multiplication processing on the nominal power of the generating vehicle and a preset power threshold value to generate a first multiplication;

the second analysis submodule is used for judging whether the third absolute value is smaller than the running current converted power of the telemechanical grid-connected detection switch or not;

From the above technical scheme, the invention has the following advantages:

responding to a received power supply quality regulation request, acquiring first working condition data of a seamless grid-connected and off-grid device, comparing the first working condition data with an associated preset working condition data threshold value, acquiring second working condition data of the seamless grid-connected and off-grid device according to a preset period according to a first comparison result, judging whether a phase angle difference of the second working condition data is in a preset switching-on interval, inputting the second working condition data into a preset deviation function when the phase angle difference is in the switching-on interval to generate a corresponding deviation value, comparing the deviation value with a preset reference deviation value, controlling a grid-connected switch of a power generation vehicle of the seamless grid-connected and off-grid device to switch on and acquiring third working condition data of the seamless grid-connected and off-grid device according to a second comparison result, and controlling a remote grid-connected detection switch of the seamless grid-connected and off-grid device to switch off a low-voltage main switch of a platform region according to the third working condition data. The method solves the technical problems that when the low-voltage power generation vehicle is in grid-connected power supply operation, a power failure switching method is often adopted, but the method can cause power failure of a user for a certain time and times, and the power supply reliability is reduced. The output power, voltage data and slip angular frequency of the low-voltage power generation car are adjusted through the seamless grid-connected/off-grid device, grid-connected power supply operation can be realized without power failure switching, and meanwhile, output current is adjusted through the power quality regulator of the seamless grid-connected/off-grid device during grid-connected power supply, so that power supply reliability is improved.

Drawings

In order to more clearly illustrate the embodiments of the invention or the technical solutions of the prior art, the drawings which are used in the description of the embodiments or the prior art will be briefly described, it being obvious that the drawings in the description below are only some embodiments of the invention, and that other drawings can be obtained from these drawings without inventive faculty for a person skilled in the art.

Fig. 1 is a flowchart of steps of a method for controlling power quality of a low-voltage power generation vehicle according to an embodiment of the present invention;

FIG. 2 is a wiring diagram of a seamless off-grid device according to a first embodiment of the present invention;

fig. 3 is a flowchart illustrating steps of a method for controlling power quality of a low-voltage power generation vehicle according to a second embodiment of the present invention;

fig. 4 is a power flow diagram of a seamless off-grid device according to a second embodiment of the present invention;

FIG. 5 is a schematic diagram of a power quality regulator of a seamless off-grid device according to a second embodiment of the present invention;

fig. 6 is a block diagram of a power quality control system for a low-voltage power generation vehicle according to a third embodiment of the present invention.

Detailed Description

The embodiment of the invention provides a method and a system for regulating and controlling the power supply quality of a low-voltage power generation vehicle, which are used for solving the technical problems that at present, when the low-voltage power generation vehicle is in grid-connected power supply operation, a power failure switching method is often adopted, but the method can cause power failure of a user for a certain time and times, and the power supply reliability is reduced.

In order to make the objects, features and advantages of the present invention more comprehensible, the technical solutions in the embodiments of the present invention are described in detail below with reference to the accompanying drawings, and it is apparent that the embodiments described below are only some embodiments of the present invention, but not all embodiments of the present invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Referring to fig. 1, fig. 1 is a flowchart illustrating steps of a method for controlling power quality of a low-voltage power generation vehicle according to an embodiment of the invention.

The invention provides a method for regulating and controlling the power supply quality of a low-voltage power generation vehicle, which is applied to a seamless parallel off-grid device and comprises the following steps:

referring to fig. 2, the seamless grid-connected/disconnected device includes a seamless grid-connected/disconnected controller, an electric energy quality regulator and a remote grid-connected detection switch QF5. And the seamless grid-off controller can collect the voltage data, the current data, the side network system voltage data and the side network system current data of the low-voltage power generation vehicle in real time. The telemechanical grid-connected detection switch QF5 is arranged between the load end and the output end of the side grid system. One end of a generator car grid-connected switch QF3 is connected with the output end of the low-voltage generator car, and the other end of the generator car grid-connected switch QF3 is respectively connected with one end of a generator access switch QF4 and the electric energy quality regulator.

It is worth mentioning that the seamless off-grid controller respectively collects three-phase current and three-phase voltage signals of the grid side and the machine side, and can remotely control the on-off of the QF5 telemechanical grid-connected detection switch and the QF3 generator car grid-connected switch through signal cables. The power is normally supplied to the transformer area, the generator access switch QF4 and the generator car grid-connected switch QF3 are confirmed to be at the brake separating position, and the generator is started after being connected to the lower end of the QF 4.

It is worth mentioning that QF5 (remote grid-connected detection switch) is configured on site with the low-voltage side main switch of the transformer area not having the remote function, so as to thoroughly avoid the risk of manual switch-on. After QF5 switch is closed, manual operation of the low-voltage side main switch of the platform area is allowed.

And step 101, responding to the received power supply quality regulation and control request, and acquiring first working condition data of the seamless off-grid device.

The power supply quality regulation and control request refers to a regulation and control request sent by a low-voltage power generation vehicle needing grid-connected power supply operation.

The first operating condition data refers to power data of the grid-side system and power data at the low-voltage generator car, including but not limited to generator car voltage, grid-side system voltage, generator car frequency, and grid-side system frequency.

In the embodiment of the invention, when a power supply quality regulation request is received, first working condition data of an associated network side system and a low-voltage power generation vehicle of a seamless off-grid device are acquired.

Step 102, comparing the first working condition data with an associated preset working condition data threshold value, and acquiring second working condition data of the seamless off-grid device according to a preset period and a first comparison result.

The working condition data threshold value refers to a working condition threshold value set for judging whether the closing condition of the grid-connected switch of the generator car is met or not, and the working condition threshold value comprises a voltage deviation threshold value and a frequency deviation threshold value.

In the embodiment of the invention, a first absolute value of a first difference value between the power generation vehicle voltage and the network side system voltage is calculated, a second absolute value of a second difference value between the power generation vehicle frequency and the network side system frequency is calculated, whether the first absolute value is smaller than or equal to a voltage deviation threshold value is judged, when the first absolute value is larger than the voltage deviation threshold value, the power generation vehicle voltage of the low-voltage power generation vehicle is regulated through a seamless parallel separation device, whether the second absolute value is smaller than or equal to the frequency deviation threshold value is judged, and when the second absolute value is larger than the frequency deviation threshold value, the power generation vehicle frequency of the low-voltage power generation vehicle is regulated through the seamless parallel separation device. And when the first absolute value is smaller than or equal to the voltage deviation threshold value and the second absolute value is smaller than or equal to the frequency deviation threshold value, acquiring second working condition data of the seamless off-grid device according to a preset period.

It should be noted that the second working condition data includes, but is not limited to, a leading closing phase angle that leads the 360 degrees point, a slip angular frequency, a time from a closing signal to a closing of the breaker contact, a slip angular acceleration, a calculated point angle value, a time interval between two calculated points, and the like.

And step 103, judging whether the phase angle difference of the second working condition data is in a preset closing interval.

The closing interval refers to a section in which the phase angle difference between two phasors gradually decreases.

In the embodiment of the invention, whether the phase angle in the second working condition data is in a pi-2 pi interval is judged.

And 104, inputting second working condition data into a preset deviation function when the phase angle difference is in a closing interval, and generating a corresponding deviation value.

In the embodiment of the invention, when the phase angle difference is in the pi-2 pi interval, the second working condition data is input into a preset deviation function to generate a corresponding deviation value.

And 105, comparing the deviation value with a preset reference deviation value, and controlling a grid-connected switch of the power generation vehicle of the seamless grid-connected and off-grid device to be switched on according to a second comparison result and acquiring third working condition data of the seamless grid-connected and off-grid device.

Reference to an offset value refers to calculating an allowable error value.

In the embodiment of the invention, whether the deviation value is smaller than or equal to the calculated allowable deviation value is judged, when the deviation value is larger than the calculated allowable deviation value, the second working condition parameter is obtained again at the next time point, the deviation value is calculated again, and when the deviation value is smaller than or equal to the allowable deviation value, the power generation vehicle grid-connected switch of the seamless grid-connected and off-grid device is controlled to be switched on, and the third working condition data of the seamless grid-connected and off-grid device is obtained.

It should be noted that the third working condition data includes, but is not limited to, a power generation vehicle output power, a network side system power, a remote grid-connected detection switch running current converted power and a power generation vehicle nominal power.

And 106, controlling the closing of the telemechanical grid-connected detection switch and the opening of the low-voltage main switch of the transformer area of the seamless grid-connected and off-grid device according to the third working condition data.

In the embodiment of the invention, a third absolute value of a third difference value between the output power of the power generation vehicle and the power of the network side system is calculated, whether the third absolute value is smaller than the converted power of the running current of the telemechanical grid-connected detection switch and whether the converted power of the running current of the telemechanical grid-connected detection switch is smaller than the nominal power of the power generation vehicle or not is judged, when both conditions are met, the telemechanical grid-connected detection switch of the seamless grid-connected device and the low-voltage main switch of the platform area are controlled to be switched on, and when either condition is not met, third working condition data of the seamless grid-connected device and the network-connected device are acquired again after waiting for a preset time.

In the embodiment of the invention, first working condition data of a seamless grid-connected and off-grid device is obtained in response to a received power supply quality regulation request, the first working condition data is compared with an associated preset working condition data threshold value, second working condition data of the seamless grid-connected and off-grid device is obtained according to a preset period according to a first comparison result, whether the phase angle difference of the second working condition data is in a preset switching-on interval is judged, when the phase angle difference is in the switching-on interval, the second working condition data is input into a preset deviation function to generate a corresponding deviation value, the deviation value is compared with a preset reference deviation value, a generator car grid-connected switch of the seamless grid-connected and off-grid device is controlled to be switched on according to a second comparison result, third working condition data of the seamless grid-connected and off-grid device is obtained, and switching-on of a remote grid-connected detection switch of the seamless grid-connected and a low-voltage total switch of a platform region is controlled according to the third working condition data. The method solves the technical problems that when the low-voltage power generation vehicle is in grid-connected power supply operation, a power failure switching method is often adopted, but the method can cause power failure of a user for a certain time and times, and the power supply reliability is reduced. The output power, voltage data and slip angular frequency of the low-voltage power generation car are adjusted through the seamless grid-connected/off-grid device, grid-connected power supply operation can be realized without power failure switching, and meanwhile, output current is adjusted through the power quality regulator of the seamless grid-connected/off-grid device during grid-connected power supply, so that power supply reliability is improved.

Referring to fig. 3, fig. 3 is a flowchart illustrating a method for controlling power quality of a low-voltage power generation vehicle according to a second embodiment of the present invention.

step 201, responding to a received power supply quality regulation request, and acquiring first working condition data of a seamless off-grid device.

In the embodiment of the invention, when the power supply quality regulation request is received, the power generation vehicle voltage, the network side system voltage, the power generation vehicle frequency and the network side system frequency of the seamless off-network device are acquired.

Step 202, comparing the first working condition data with an associated preset working condition data threshold value, and acquiring second working condition data of the seamless off-grid device according to a preset period and a first comparison result.

Further, the first operating condition data includes a generator car voltage, a grid-side system voltage, a generator car frequency, and a grid-side system frequency, the operating condition data threshold includes a voltage deviation threshold and a frequency deviation threshold, and step 202 includes the following substeps:

s11, carrying out difference processing on the voltage of the power generation vehicle and the system voltage at the network side to generate a first difference value;

s12, carrying out difference processing on the frequency of the power generation vehicle and the frequency of the network side system to generate a second difference value;

S13, respectively calculating a first absolute value of the first difference value and a second absolute value of the second difference value;

in the embodiment of the invention, the voltage of the generator car, the voltage of the network side system, the frequency of the generator car and the frequency of the network side system are input into a preset voltage-frequency function, and corresponding voltage difference and frequency difference are generated.

It should be noted that the voltage-frequency function is specifically:

；

wherein,for generating vehicle voltage, ">For the network-side system voltage, +.>For the frequency of the power generation vehicle,/>for the network side system frequency, +.>For the voltage difference, & lt & gt>Is the frequency difference.

S14, judging whether the first absolute value is smaller than or equal to a voltage deviation threshold.

The voltage deviation threshold refers to a voltage deviation preset value, and takes 5% of the nominal voltage of the access system, i.e. 380v×5+=19v.

In the embodiment of the invention, whether the voltage difference is smaller than or equal to 19V is judged.

And S15, if the first absolute value is larger than the voltage deviation threshold, performing first pulse adjustment on the seamless off-grid device according to the first difference value, and jumping to execute the step of acquiring first working condition data of the seamless off-grid device.

In the embodiment of the invention, when the voltage difference is greater than 19V, according to the PID regulation rule, a voltage regulation pulse width tu is formed according to the voltage difference, the voltage regulation pulse is output through a relay contact by an opening circuit and acts on an automatic regulation exciting device of a power generation vehicle to change the target voltage of the automatic regulation exciting device, the voltage difference is enabled to quickly enter a set range through the regulation of the automatic device, and the step of obtaining the first working condition data of the seamless off-grid device is skipped.

S16, if the first absolute value is smaller than or equal to the voltage deviation threshold, judging whether the second absolute value is smaller than or equal to the frequency deviation threshold.

The frequency deviation threshold refers to the allowable range of the frequency error, taking 0.05Hz.

In the embodiment of the invention, when the voltage difference is smaller than or equal to 19V, whether the frequency difference is 0.05Hz is judged.

And S17, if the second absolute value is larger than the frequency deviation threshold value, performing second pulse adjustment on the seamless off-grid device according to the second difference value, and jumping to execute the step of acquiring the first working condition data of the seamless off-grid device.

In the embodiment of the invention, when the frequency difference is larger than 0.05Hz, the frequency modulation pulse width tf is formed according to the frequency difference according to the PID regulation rule, the frequency modulation is carried out on the generator car only when the frequency difference does not meet the requirement, and the speed regulation pulse passes through the switching-on circuit and acts on the speed regulation loop through the relay contact to realize speed regulation. And skipping to execute the step of acquiring the first working condition data of the seamless off-grid device.

And S18, if the second absolute value is smaller than or equal to the frequency deviation threshold value, acquiring second working condition data of the seamless off-grid device according to a preset period.

In the embodiment of the invention, when the frequency difference is smaller than or equal to 0.05Hz, the second working condition data of the seamless off-grid device are acquired according to the time interval of 20 minutes.

And 203, judging whether the phase angle difference of the second working condition data is in a preset closing interval.

In the embodiment of the invention, whether the phase angle difference of the second working condition data is in a pi-2 pi interval is judged.

Further, the method further comprises the following steps:

and S21, when the phase angle difference is not in the closing interval, jumping to a step of acquiring second working condition data of the seamless off-grid device according to a preset period according to a first comparison result.

In the embodiment of the invention, when the phase angle difference is in the 0-pi interval, the step of obtaining the second working condition data of the seamless off-grid device according to the first comparison result and the preset period is skipped.

When the phase angle difference is in the 0-pi interval, the phase angle difference gradually increases, and the constant time-before-time optimal pilot phase angle calculation cannot be performed.

And 204, when the phase angle difference is in the closing interval, inputting second working condition data into a preset deviation function to generate a corresponding deviation value.

It should be noted that the deviation function is specifically:

；

wherein,for a leading closing phase angle leading 360 degrees point +.>To calculate the point i slip angular frequency,time for switching-on signal to switch-off of the circuit breaker contacts, +.>For slip angular acceleration +. >For calculating the point i angle value,/>For calculating the angle value of point i-1, < >>For the time interval of two calculation points, +.>For deviation value, +.>For calculating the slip angular frequency of the points i-n, i is the number of the calculated point, n is the number of the calculated point preceding the calculated point i,/and>to calculate the point i slip angle, +.>To calculate the angle difference of point i, +.>Is the spot time interval.

Step 205, determining whether the deviation value is smaller than or equal to a preset reference deviation value.

Reference to a bias value refers to calculating an allowable error.

In the embodiment of the invention, whether the deviation value is smaller than or equal to the calculation allowable error is judged.

Step 206, if the deviation value is greater than the reference deviation value, jumping to a step of acquiring second working condition data of the seamless off-grid device according to the first comparison result and the preset period.

In the embodiment of the invention, when the deviation value is larger than the calculation allowable error, the step of obtaining the second working condition data of the seamless off-grid device according to the first comparison result and the preset period is skipped until the deviation value is smaller than the calculation allowable error.

And step 207, if the deviation value is smaller than or equal to the reference deviation value, controlling a grid-connected switch of the power generation vehicle of the seamless grid-connected and off-grid device to be switched on and acquiring third working condition data of the seamless grid-connected and off-grid device.

In the embodiment of the invention, referring to fig. 2, when the deviation value is smaller than or equal to the calculation tolerance, the generator car grid-connected switch QF3 of the seamless grid-connected and off-grid device is controlled to be switched on, and third working condition data of the seamless grid-connected and off-grid device is obtained.

And step 208, controlling the closing of the telemechanical grid-connected detection switch and the opening of the low-voltage main switch of the transformer area of the seamless grid-connected and off-grid device according to the third working condition data.

Further, the third working condition data includes the output power of the generator car, the power of the grid-side system, the converted power of the running current of the telemechanical grid-connected detection switch and the nominal power of the generator car, and step 208 includes the following substeps:

s31, performing difference processing on the network side system power and the power generation vehicle output power, generating a third difference value and calculating a third absolute value of the third difference value;

s32, multiplying the nominal power of the generating vehicle by a preset power threshold value to generate a first multiplication value.

S33, judging whether the third absolute value is smaller than the converted power of the operating current of the telemechanical grid-connected detection switch;

S34, if the third absolute value is greater than or equal to the converted power of the running current of the telemechanical grid-connected detection switch, jumping to the step of obtaining third working condition data of the seamless grid-connected and off-grid device;

and S35, if the third absolute value is smaller than the remote grid-connected detection switch operation current conversion power, judging whether the remote grid-connected detection switch operation current conversion power is smaller than a first multiplication value.

S36, if the converted power of the running current of the remote grid-connected detection switch is larger than or equal to the first multiplication value, jumping to a step of acquiring third working condition data of the seamless grid-connected and off-grid device;

in the embodiment of the invention, the output power of the power generation vehicle, the power of the network side system, the running current converted power of the telemechanical grid-connected detection switch and the nominal power of the power generation vehicle are input into a preset seamless off-grid discriminant function, and whether the third working condition data meet the condition of the seamless off-grid discriminant function is judged. And when the seamless off-grid judging function judging condition is not met, jumping to the step of acquiring the third working condition data of the seamless off-grid device.

The seamless off-grid discriminant function is specifically as follows:

；

wherein,for the network-side system power,/>for generating power, < > for the electric car>And converting the running current of the remote grid-connected detection switch into power, wherein PB is the nominal power of the generating vehicle.

And S37, if the converted power of the running current of the telemechanical grid-connected detection switch is smaller than the first multiplication value, controlling the telemechanical grid-connected detection switch of the seamless grid-connected device to be switched on and the low-voltage main switch of the transformer area to be switched off.

In the embodiment of the invention, referring to fig. 4, when the third working condition data meets the condition of judging the seamless off-grid judging function, and the output power of the generator car reaches P2, the controller sends a closing command to QF5 (telemechanical grid-connected detection switch), after QF5 closing is completed, QF1 (platform area low-voltage master switch) is manually separated, and the seamless off-grid is completed.

Further, after step 208, the following steps are included:

s41, responding to the received off-grid request, and acquiring the power generation vehicle voltage data and the grid-side system voltage data of the seamless off-grid device at the current moment.

In the embodiment of the invention, the generating vehicle voltage phase, the generating vehicle voltage frequency, the generating vehicle voltage amplitude, the network side system voltage phase, the network side system voltage frequency and the network side system voltage amplitude of the seamless off-network device at the current moment are obtained in response to the received off-network request.

And S42, when the voltage data of the generator car is the same as the voltage data of the network side system, controlling the remote grid-connected detection switch and the low-voltage main switch of the platform area to be switched on and the generator car grid-connected switch to be switched off.

In the embodiment of the invention, when the output voltage of the power generation vehicle reaches three values of phase, frequency and amplitude, the three values are completely equal to the network side system. And automatically sending a closing pulse to QF5, after the QF5 completes closing, manually closing a low-voltage side main switch of the platform area, and switching off QF3 by a controller, so that the generator car is out of operation.

It should be noted that referring to fig. 5, the power quality regulator is connected in parallel withBetween the low voltage generator car and the load, A, B phase current transfer is taken as an example: assuming that the A-phase load current is smaller than the B-phase load current, the regulation and control target is the output current of the low-voltage generator car. The converter outlet voltage can be controlled by pulse width modulation>Is smaller than the bus voltage of the low-voltage power generation vehicle>And the phase A of the converter is in a current taking state. Similarly, control->Voltage is greater than->The current transformer B phase is in a current output state, and the load current is transferred from the B phase to the a phase. According to the load current function, the current source control is adopted for the converter, so that the purpose of balancing three-phase current can be achieved. The low-voltage power generation car can output in full capacity under the three-phase balance state.

Wherein,is the phase A current of the low-voltage generator car, +.>B-phase current of low-voltage generator car, +.>Is the C-phase current of the low-voltage power generation car.

The load current function is specifically:

；

wherein,is the phase A current of the low-voltage generator car, +.>B-phase current of low-voltage generator car, +.>For the phase a current on the user side,for the user side B-phase current, +.>Is the inductance L _A Current at (I/O)>Is the inductance L _B A current.

Referring to fig. 6, fig. 6 is a block diagram illustrating a power quality control system for a low-voltage power generation vehicle according to a third embodiment of the present invention.

The invention provides a power supply quality regulation and control system of a low-voltage power generation vehicle, which is applied to a seamless parallel off-grid device and comprises the following components:

the first acquisition module 301 is configured to obtain first working condition data of the seamless off-grid device in response to the received power quality regulation request;

the first control module 302 is configured to compare the first working condition data with an associated preset working condition data threshold, and obtain, according to a first comparison result, second working condition data of the seamless off-grid device according to a preset period;

the first analysis module 303 is configured to determine whether the phase angle difference of the second working condition data is in a preset closing interval;

the second analysis module 304 is configured to input second working condition data into a preset deviation function when the phase angle difference is in a closing interval, and generate a corresponding deviation value;

the second control module 305 is configured to compare the deviation value with a preset reference deviation value, and control the power generation vehicle grid-connected switch of the seamless grid-connected and off-grid device to switch on and obtain third working condition data of the seamless grid-connected and off-grid device according to a second comparison result;

and the third control module 306 is used for controlling the closing of the telemechanical grid-connected detection switch and the opening of the low-voltage main switch of the platform region of the seamless grid-connected and off-grid device according to third working condition data.

Further, the first operating condition data includes a generator car voltage, a grid-side system voltage, a generator car frequency, and a grid-side system frequency, the operating condition data threshold includes a voltage deviation threshold and a frequency deviation threshold, and the first control module 302 includes:

the first difference submodule is used for carrying out difference processing on the voltage of the power generation vehicle and the voltage of the network side system to generate a first difference;

the second difference submodule is used for carrying out difference processing on the frequency of the power generation vehicle and the frequency of the network side system to generate a second difference;

an absolute value sub-module for calculating a first absolute value of the first difference and a second absolute value of the second difference, respectively;

the first analysis submodule is used for judging whether the first absolute value is smaller than or equal to a voltage deviation threshold value or not;

if the first absolute value is larger than the voltage deviation threshold, performing first pulse adjustment on the seamless off-grid device according to the first difference value, and performing jump execution to obtain first working condition data of the seamless off-grid device;

if the second absolute value is larger than the frequency deviation threshold value, performing second pulse adjustment on the seamless off-grid device according to the second difference value, and performing jump to acquire first working condition data of the seamless off-grid device;

Further, the deviation function is specifically:

；

；/>

；

Further, the second control module 305 includes:

the first control sub-module is used for jumping to the step of acquiring second working condition data of the seamless off-grid device according to a preset period according to a first comparison result if the deviation value is larger than a reference deviation value;

and the second control sub-module is used for controlling the grid-connected switch of the power generation vehicle of the seamless grid-connected and off-grid device to be switched on and acquiring third working condition data of the seamless grid-connected and off-grid device if the deviation value is smaller than or equal to the reference deviation value.

Further, the third working condition data includes the output power of the generator car, the power of the grid-side system, the converted power of the running current of the telemechanical grid-connected detection switch and the nominal power of the generator car, and the third control module 306 includes:

the third difference value submodule is used for carrying out difference value processing on the network side system power and the output power of the generating vehicle, generating a third difference value and calculating a third absolute value of the third difference value;

the second analysis submodule is used for judging whether the third absolute value is smaller than the converted power of the running current of the telemechanical grid-connected detection switch;

if the third absolute value is smaller than the converted power of the operation current of the telemechanical grid-connected detection switch, judging whether the converted power of the operation current of the telemechanical grid-connected detection switch is smaller than a first multiplication value or not;

And if the converted power of the running current of the telemechanical grid-connected detection switch is smaller than the first multiplication value, controlling the telemechanical grid-connected detection switch of the seamless grid-connected device to be switched on and the low-voltage main switch of the transformer area to be switched off.

Further comprises:

and the jump module is used for jumping to the step of acquiring second working condition data of the seamless off-grid device according to the first comparison result and the preset period when the phase angle difference is not in the switching-on interval.

Further comprises:

the off-grid module is used for responding to the received off-grid request and acquiring the voltage data of the generator car and the voltage data of the grid-side system of the seamless off-grid device at the current moment;

when the voltage data of the power generation vehicle is the same as the voltage data of the network side system, the remote grid-connected detection switch and the low-voltage main switch of the transformer area are controlled to be switched on, and the power generation vehicle grid-connected switch is controlled to be switched off.

It will be clear to those skilled in the art that, for convenience and brevity of description, specific working procedures of the above-described systems, apparatuses and units may refer to corresponding procedures in the foregoing method embodiments, which are not repeated herein.

In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods may be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of the units is merely a logical function division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.

The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

The above embodiments are only for illustrating the technical solution of the present invention, and not for limiting the same; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. The power supply quality regulation and control method for the low-voltage power generation vehicle is characterized by being applied to a seamless parallel-off-grid device and comprising the following steps of:

controlling the remote grid-connected detection switch of the seamless grid-connected and off-grid device to be switched on and the low-voltage main switch of the transformer area to be switched off according to the third working condition data;

the first working condition data comprises a power generation vehicle voltage, a network side system voltage, a power generation vehicle frequency and a network side system frequency, the working condition data threshold comprises a voltage deviation threshold and a frequency deviation threshold, the steps of comparing the first working condition data with an associated preset working condition data threshold and obtaining second working condition data of the seamless off-network device according to a first comparison result and a preset period comprise the following steps:

if the second absolute value is smaller than or equal to the frequency deviation threshold value, acquiring second working condition data of the seamless parallel off-grid device according to a preset period;

the second working condition data comprise a leading closing phase angle, a slip angular frequency, time from a closing signal to closing of a contact of the circuit breaker, slip angular acceleration, calculated point angle values and time intervals of two calculated points, wherein the leading closing phase angle is ahead of 360 degrees;

The deviation function is specifically:

；

wherein,for a leading closing phase angle leading 360 degrees point +.>To calculate the point i slip angular frequency, +.>Time for switching-on signal to switch-off of the circuit breaker contacts, +.>For slip angular acceleration +.>In order to calculate the angle value of the point i,for calculating the angle value of point i-1, < >>For the time interval of two calculation points, +.>For deviation value, +.>For calculating the slip angular frequency of the points i-n, i is the number of the calculated point, n is the number of the calculated point preceding the calculated point i,/and>in order to calculate the slip angle for point i,to calculate the angle difference of point i, +.>Is a point location time interval;

the step of comparing the deviation value with a preset reference deviation value, controlling the power generation vehicle grid-connected switch of the seamless grid-connected and off-grid device to be switched on according to a second comparison result and obtaining third working condition data of the seamless grid-connected and off-grid device comprises the following steps:

if the deviation value is smaller than or equal to the reference deviation value, controlling a generator car grid-connected switch of the seamless grid-connected and off-grid device to be switched on and acquiring third working condition data of the seamless grid-connected and off-grid device;

The third working condition data comprises power generation vehicle output power, network side system power, remote grid-connected detection switch running current converted power and power generation vehicle nominal power, and the steps of controlling the remote grid-connected detection switch of the seamless parallel-to-grid device to switch on and the platform zone low-voltage main switch to switch off according to the third working condition data comprise the following steps:

2. The low-voltage power generation vehicle power supply quality regulation method according to claim 1, further comprising:

3. The low-voltage power generation vehicle power supply quality regulation method according to claim 1, further comprising:

4. The utility model provides a low voltage power generation car power quality regulation and control system which characterized in that is applied to seamless and off-grid device, includes:

the third control module is used for controlling the remote grid-connected detection switch of the seamless grid-connected and off-grid device to be switched on and the low-voltage main switch of the transformer area to be switched off according to the third working condition data;

the first working condition data comprises a power generation vehicle voltage, a network side system voltage, a power generation vehicle frequency and a network side system frequency, the working condition data threshold comprises a voltage deviation threshold and a frequency deviation threshold, and the first control module comprises:

The first difference value submodule is used for carrying out difference value processing on the voltage of the power generation vehicle and the voltage of the network side system to generate a first difference value;

the second difference value submodule is used for carrying out difference value processing on the frequency of the power generation vehicle and the frequency of the network side system to generate a second difference value;

the first analysis submodule is used for judging whether the first absolute value is smaller than or equal to the voltage deviation threshold value;

the deviation function is specifically:

；

the second control module includes:

The second control sub-module is used for controlling the grid-connected switch of the seamless grid-connected and off-grid device to be switched on and acquiring third working condition data of the seamless grid-connected and off-grid device if the deviation value is smaller than or equal to the reference deviation value;

the third working condition data comprise power generation vehicle output power, network side system power, remote grid-connected detection switch running current converted power and power generation vehicle nominal power, and the third control module comprises: