CN110752664A - Dual-power-supply fast switching device - Google Patents
Dual-power-supply fast switching device Download PDFInfo
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- CN110752664A CN110752664A CN201911097251.5A CN201911097251A CN110752664A CN 110752664 A CN110752664 A CN 110752664A CN 201911097251 A CN201911097251 A CN 201911097251A CN 110752664 A CN110752664 A CN 110752664A
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- 230000003111 delayed effect Effects 0.000 claims abstract description 5
- 238000005259 measurement Methods 0.000 claims description 45
- 230000009977 dual effect Effects 0.000 claims description 5
- 230000002238 attenuated effect Effects 0.000 claims description 4
- 230000005611 electricity Effects 0.000 claims description 4
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- 230000002159 abnormal effect Effects 0.000 claims description 2
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J9/00—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting
- H02J9/04—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source
- H02J9/06—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source with automatic change-over, e.g. UPS systems
- H02J9/066—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source with automatic change-over, e.g. UPS systems characterised by the use of dynamo-electric machines
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Abstract
The invention discloses a dual-power bus-bar mutual-throw device, which executes a load shedding program according to a preset current fixed value and a cutting sequence and simultaneously carries out rapid switching when a power supply and a power switch on any side have faults; when the fast switching condition can not be met, carrying out synchronous switching; when the synchronous switching condition cannot be met, performing residual voltage switching; when the synchronous switching condition can not be met, carrying out delayed switching; the switching modes are respectively as follows: series switching, simultaneous switching, parallel automatic switching, parallel semi-automatic switching, and manual switching. The invention selects the power supply switching mode with the minimum damage to the power grid and equipment within the longest voltage loss time allowed by the power grid for power supply switching, can be widely applied to industrial and mining enterprises with a large amount of motor equipment, such as power supply switching of occasions with more high-voltage motor loads, such as chemical industry, coal industry, metallurgy and the like, and has higher requirements on power supply switching.
Description
Technical Field
The invention belongs to the field of power control, relates to a dual-power switching device, and particularly relates to a dual-power rapid switching device.
Background
With the continuous development of national economy, the requirements on power systems are higher and higher, a large number of devices such as relay protection, automatic devices and circuit breakers are installed in a power grid, and particularly, a small and miniature distributed power supply is installed in a power utilization system, so that a power supply network becomes complex. The power grid is more and more huge, and equipment increases, and the probability that the electric wire netting breaks down is also higher, appears supplying power interruption phenomenon easily, causes the influence to industrial enterprise and resident's life, and for this reason, most electricity distribution rooms have all adopted dual power supply system. However, in the current dual-power-supply power grid, an operation interruption (power supply interruption of a load carried by a power supply) or equipment impact damage can be caused in the process of switching between the dual power supplies, especially when the power supply is suddenly interrupted, because the motor in the system is in idle running, the motor has residual voltage in a short time, and the step-out operation of the small micro distributed power supply can cause the residual voltage, and at the moment, if the external power supply is directly switched in again, unnecessary loss can be caused due to deviation of a phase angle.
Disclosure of Invention
The invention solves the technical problem of how to select the power supply switching mode with the minimum damage to the power grid and equipment within the longest voltage loss time allowed by the power grid to carry out power supply switching.
The invention relates to a double-power-supply quick switching device which comprises a main power supply, a standby power supply, a main power supply voltage measurement PT1, a standby power supply voltage measurement PT2, a main power supply current measurement CT1, a standby power supply current measurement CT2, a main power supply breaker DL1, a standby power supply breaker DL2 and a controller CU, wherein the main power supply is connected with the main power supply voltage measurement PT1 and is connected with the main power supply breaker DL1 through the main power supply current measurement CT 1; the standby power supply is connected with a standby power supply voltage measurement PT2 and is connected with a standby power supply circuit breaker DL2 through a standby power supply current measurement CT2, the outgoing line ends of a main power supply circuit breaker DL1 and a standby power supply circuit breaker DL2 are connected with a bus, the bus is connected with load feeder circuit breakers 1 DL-NDL, the measurement signals of the main power supply circuit voltage measurement PT1, the standby power supply circuit voltage measurement PT2, the main power supply current measurement CT1 and the standby power supply current measurement CT2 are connected to a controller CU through signal lines, and the state signals and control lines of the main power supply circuit breaker DL1, the standby power supply circuit breaker DL2 and the feeder circuit breakers 1 DL-21 DL are connected with the controller CU; the load feeder circuit breakers 1 DL-NDL are divided into a first-level load, a second-level load and a third-level load according to the electricity utilization property of the load feeder circuit breakers through presetting of a controller CU.
The invention discloses a double-power-supply quick switching device, which comprises the following steps:
when the main power supply fails, the controller CU records normal running current before the main power supply fails, compares a set current fixed value of the standby power supply, and directly switches the power supply if the set current fixed value of the standby power supply is smaller than the set current fixed value of the standby power supply; if the current value is larger than the set current fixed value of the standby power supply, performing power supply switching after a load shedding program is executed according to the value exceeding the set current fixed value of the standby power supply;
judging whether a power grid meets a condition of rapid switching or not when switching a power supply, if so, tripping off a main power supply circuit breaker DL1 and switching on a standby power supply circuit breaker DL 2;
if the fast switching condition is not met, tripping off the main power supply circuit breaker DL1, tracking the frequency difference and angle difference change of residual voltage in real time, and switching on the standby power supply circuit breaker DL2 when the feedback voltage and the standby power supply voltage are superposed on the first phase to complete synchronous switching;
if the synchronous switching condition is not met, when the residual voltage is attenuated to 20% -40% of rated voltage, tripping off the main power supply breaker DL1, switching on the standby power supply breaker DL2, and completing residual voltage switching;
if the voltage is delayed and reduced to the residual voltage switching constant value after the main power supply fails, long-delay switching is carried out, and after the delay is exceeded, the main power supply breaker DL1 is directly tripped regardless of the change of the voltage and the frequency, and the standby power supply breaker DL2 is switched.
When the main power supply exceeds the set current value, the load shedding program is executed firstly, and the power supply switching step can be executed when the main power supply still exceeds the set current value after the load shedding program is executed.
The load shedding program is executed, and the load shedding sequence is as follows: three-level load and two-level load, and the first-level load is not subjected to load shedding.
The power failure includes: loss of voltage, undervoltage, overvoltage, and phase loss.
Drawings
The invention is described in further detail below with reference to the following figures and detailed description:
FIG. 1 is a schematic diagram of a system structure of a dual power supply fast switching device according to the present invention;
FIG. 2 is a vector diagram of bus residual voltage of motor switching of the dual power supply fast switching device according to the present invention.
Detailed Description
The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.
In the following description, a detailed structure will be presented for a thorough understanding of embodiments of the invention. It is apparent that the implementation of the embodiments of the present invention is not limited to the specific details familiar to those skilled in the art. The following detailed description of the preferred embodiments of the invention, however, the invention is capable of other embodiments in addition to those detailed.
The invention relates to a double-power-supply quick switching device which comprises a main power supply, a standby power supply, a main power supply voltage measurement PT1, a standby power supply voltage measurement PT2, a main power supply current measurement CT1, a standby power supply current measurement CT2, a main power supply breaker DL1, a standby power supply breaker DL2 and a controller CU, wherein the main power supply is connected with the main power supply voltage measurement PT1 and is connected with the main power supply breaker DL1 through the main power supply current measurement CT 1; the standby power supply is connected with a standby power supply voltage measurement PT2 and is connected with a standby power supply circuit breaker DL2 through a standby power supply current measurement CT2, the outgoing line ends of a main power supply circuit breaker DL1 and a standby power supply circuit breaker DL2 are connected with a bus, the bus is connected with load feeder circuit breakers 1 DL-NDL, the measurement signals of the main power supply circuit voltage measurement PT1, the standby power supply circuit voltage measurement PT2, the main power supply current measurement CT1 and the standby power supply current measurement CT2 are connected to a controller CU through signal lines, and the state signals and control lines of the main power supply circuit breaker DL1, the standby power supply circuit breaker DL2 and the feeder circuit breakers 1 DL-21 DL are connected with the controller CU; the load feeder circuit breakers 1 DL-NDL are divided into a first-level load, a second-level load and a third-level load according to the electricity utilization property of the load feeder circuit breakers through presetting of a controller CU.
The invention discloses a double-power-supply quick switching device, which comprises the following steps:
when the main power supply fails, the controller CU records normal running current before the main power supply fails, compares a set current fixed value of the standby power supply, and directly switches the power supply if the set current fixed value of the standby power supply is smaller than the set current fixed value of the standby power supply; if the current value is larger than the set current fixed value of the standby power supply, performing power supply switching after a load shedding program is executed according to the value exceeding the set current fixed value of the standby power supply;
when switching power supplyFirstly, judging whether a power grid meets a condition of rapid switching, if so, tripping off a main power supply breaker DL1, and switching on a standby power supply breaker DL 2; as shown in fig. 2, VDIs the residual voltage of bus, VS△ U is the beat voltage between the standby power supply voltage and the bus residual voltage, and the voltage U borne by the motor after the standby power supply is closedMComprises the following steps:
UM= XM/ (XS＋XM) △U
in the formula, XMEquivalent reactance, X, after conversion of the motor unit and the low-voltage load on the bus to the high-voltage service voltageS-the equivalent reactance of the power supply; to ensure safe self-starting of the motor, UMIn fig. 2, an arc line a '-a "is drawn with a circle center a and a radius of 1.64, the right side of the arc line a' -a" is a safe area where the power supply 2 is allowed to be switched on, and the left side is an unsafe area; after the bus is de-energized, the residual voltage phasor end point moves from the direction A to the direction B along the residual voltage curve, if a standby power supply can be switched on in the section A-B, the safety of the motor can be ensured, the rotating speed of the motor is not reduced too much, and the quick switching is completed; two setting values of rapid switching are provided, namely a frequency difference and a phase angle difference, and an actually measured value is compared with the setting values immediately before the device sends a closing command to judge whether a closing condition is met.
If the fast switching condition is not met, tripping off the main power supply circuit breaker DL1, tracking the frequency difference and angle difference change of residual voltage in real time, and combining the standby circuit breaker DL2 when the feedback voltage and the standby power supply voltage coincide with the first phase to complete synchronous switching; there are two simultaneous capture switching setting values, namely a frequency difference and a phase angle difference when a constant leading phase angle mode is adopted; when a constant time-ahead mode is adopted, the frequency difference and the total closing loop time are obtained; in the synchronous capture mode, the frequency difference setting can take a larger value;
if the synchronous switching condition is not met, when the residual voltage is attenuated to 20% -40% of rated voltage, tripping off the main power supply breaker DL1, switching on the standby power supply breaker DL2, and completing residual voltage switching;
if the voltage is delayed and reduced to the residual voltage switching constant value after the voltage of the main power supply fails, long-delay switching is carried out, and after the delay is exceeded, the main power supply breaker DL1 is directly tripped regardless of the change of the voltage and the frequency, and the standby power supply breaker DL2 is switched.
The load shedding program is executed, and the load shedding sequence is as follows: three-level load and two-level load, and the first-level load is not subjected to load shedding.
When the negative sequence voltage is higher than 8V, or the positive sequence voltage is lower than 30V, and the voltage is higher than the voltage threshold value, the device judges that the PT is broken after 5S delay; after the PT is disconnected, if the voltage is recovered and the conditions are not met any more, returning instantly; the PT disconnection alarm can lock all switching protection.
The controller CU latches when it detects the following conditions: a) the switch position is abnormal (the incoming line 1, the incoming line 2 switch and the bus coupler switch are all on or off, and a locking signal is sent out after 30S delay; the PT disconnecting switch is not closed, and the delay time is 0.5S to send a locking signal); b) backup power-off locking; c) PT disconnection locking; d) and (4) protecting and locking.
When the standby power supply is switched to the fault bus, the standby power supply breaker DL2 is switched off in an accelerated manner.
The device is provided with four switching modes: 1 serial switching, 2 simultaneous switching, 3 parallel automatic switching and 4 parallel semi-automatic switching. After the soft pressing plate is put into the device, the device is started by manual operation of operators, and the quick switching device carries out switching-on and switching-off operation according to a preset manual switching mode.
Starting by a protection contact, starting a controller CU for switching while protecting an outlet tripping working power supply circuit breaker, and performing switching-on and switching-off operation by the controller CU according to a preset automatic switching mode (series connection and simultaneous connection);
when the incoming line current is suddenly changed, the incoming line side is regarded as a fault, and the fast switching protection is locked.
And after the bus voltage is lower than the setting voltage and the setting delay is reached, the device automatically starts and switches according to an automatic mode.
When the operating power supply breaker is tripped illegally, the auxiliary contact starting device of the operating switch closes the standby power supply breaker DL2 when the switching condition is met.
The invention is suitable for industrial and mining enterprises with a large amount of motor equipment, such as power supply switching of occasions with more high-voltage motor loads, such as chemical industry, coal industry, metallurgy and the like, the requirements on power supply switching are higher, and the invention can not cause operation interruption or equipment impact damage during power supply switching.
Claims (7)
1. A dual-power bus-coupler mutual-throw device comprises a 1# power supply, a 2# power supply, a 1# power supply voltage measurement PT1, a 2# power supply voltage measurement PT2, a 1# power supply current measurement CT1, a 2# power supply current measurement CT2, a 1# power supply circuit breaker DL1, a 2# power supply circuit breaker DL2, a bus-coupler circuit breaker DL3, a section I bus voltage measurement PT3, a section II bus voltage measurement PT4, a section I load feeder circuit breaker 11 DL-1 NDL, a section II load feeder circuit breaker 21 DL-2 NDL and a controller CU, wherein the 1# power supply is connected with the 1# power supply voltage measurement PT1 and is connected with the section I power supply circuit breaker DL1 through the section 1# power supply current measurement CT1, the section 1# power supply circuit breaker DL1 is connected with the section I bus, and the section I bus is further connected with the section I bus voltage measurement PT3 and the section I load feeder circuit breaker 11 DL-; the 2# power supply is connected with a 2# power supply voltage measurement PT2 and is connected with a 2# power supply circuit breaker DL2 through a 2# power supply current measurement CT2, the 2# power supply circuit breaker DL2 is connected with a section II bus, the section II bus is also connected with a section II bus voltage measurement PT4 and a section II load feeder circuit breaker 21 DL-2 NDL, a bus coupler circuit breaker DL3 is connected between the section I bus and the section II bus, the measurement signals of the section I bus voltage measurement PT1, the section 2 power supply line voltage measurement PT2, the section II power supply current measurement CT1, the section 2# power supply current measurement CT2, the section I bus voltage measurement PT3 and the section II bus voltage measurement PT4 are connected to a controller CU through signal lines, and the section 1# power supply circuit breaker DL1, the section 2# power supply circuit breaker DL2, the bus coupler circuit breaker DL3, the section I load three-stage load circuit breaker 11DL, the section I load feeder circuit breaker 12DL, the section II load feeder, The state signal and control line of the second-stage load feeder circuit breaker 22DL at the section II are connected with the controller CU;
the I section of load feeder circuit breaker 11 DL-1 NDL and the II section of load feeder circuit breaker 21 DL-2 NDL are preset and divided into a primary load, a secondary load and a tertiary load in different grades through a controller CU according to the electricity utilization property;
the utility model provides a device is thrown each other to dual supply bus-bar, its characterized in that: the control method comprises the following steps:
when the power supply is in fault, the controller CU records normal running current before the fault of the power supply 1# and adds the current running current to the current running current of the power supply 2# to compare a set current fixed value of the power supply 2# and directly switch the power supply if the set current fixed value of the power supply 2# is less than the set current fixed value of the power supply 2 #; if the current is larger than the set current fixed value of the 2# power supply, switching the power supply after executing a load shedding program according to the value exceeding the set current fixed value of the 2# power supply;
when power switching is carried out, whether a power grid meets the condition of quick switching is judged, if the condition of quick switching is met, a No. 1 power circuit breaker DL1 is tripped, and a bus coupler circuit breaker DL3 is closed; two setting values of rapid switching are provided, namely a frequency difference and a phase angle difference, and an actually measured value is compared with the setting values immediately before the device sends a closing command to judge whether a closing condition is met;
if the fast switching condition is not met, tripping off the 1# power supply circuit breaker DL1, tracking the frequency difference and angle difference change of residual voltage in real time, and combining the bus coupler circuit breaker DL3 when the first phase of the feedback voltage and the 2# power supply voltage vector is coincident to complete synchronous switching; there are two simultaneous capture switching setting values, namely a frequency difference and a phase angle difference when a constant leading phase angle mode is adopted; when a constant time-ahead mode is adopted, the frequency difference and the total closing loop time are obtained; in the synchronous capture mode, setting the frequency difference to take a larger value;
if the synchronous switching condition is not met, when the residual voltage is attenuated to 20% -40% of rated voltage, tripping off the No. 1 power supply circuit breaker DL1, closing the bus coupler circuit breaker DL3, and completing residual voltage switching;
if the voltage is delayed and reduced to a residual voltage switching fixed value after the I section bus voltage is in fault, switching is carried out with long delay, and after the delay is exceeded, the 1# power supply circuit breaker DL1 is directly tripped out and the bus coupler circuit breaker DL3 is closed regardless of the change of the voltage and the frequency;
when the No. 2 power supply fails, the controller CU records the normal running current before the No. 2 power supply fails, adds the current running current with the No. 1 power supply, compares the set current constant value of the No. 1 power supply, and directly switches the power supply if the set current constant value of the No. 1 power supply is smaller than the set current constant value of the No. 1 power supply; if the current is larger than the set current constant value of the 1# power supply, performing power supply switching after executing a load shedding program according to the value exceeding the set current constant value of the 1# power supply;
when power switching is carried out, whether a power grid meets the condition of quick switching is judged, if the condition of quick switching is met, the 2# power circuit breaker DL2 is tripped, and the bus coupler circuit breaker DL3 is closed;
if the fast switching condition is not met, tripping off the 2# power supply circuit breaker DL2, tracking the frequency difference and angle difference change of residual voltage in real time, and combining the bus coupler circuit breaker DL3 when the first phase of the feedback voltage and the 1# power supply voltage vector is coincident to complete synchronous switching;
if the synchronous switching condition is not met, when the residual voltage is attenuated to 20% -40% of rated voltage, tripping off the 2# power supply circuit breaker DL2, closing the bus coupler circuit breaker DL3, and completing residual voltage switching;
if the voltage is delayed and reduced to the residual voltage switching constant value after the voltage fault of the II-section bus, the long-delay switching is carried out, and the 2# power supply circuit breaker DL2 is directly switched off and the bus coupler circuit breaker DL3 is switched on regardless of the voltage and frequency changes after the delay is exceeded.
2. The dual-power bus-bar mutual-throw device according to claim 1, characterized in that: the load shedding program is executed, and the load shedding sequence is as follows: the method comprises the steps of three-level load of a fault section, three-level load of a non-fault section, two-level load of the fault section and two-level load of the non-fault section.
3. The dual-power bus-bar mutual-throw device according to claim 1, characterized in that: when the negative sequence voltage is higher than 8V, or the positive sequence voltage is lower than 30V, and the voltage is higher than the voltage threshold value, the device judges that the PT is broken after 5S delay; after the PT is disconnected, if the voltage is recovered and the conditions are not met any more, returning instantly; the PT disconnection alarm can lock all switching protection.
4. The dual-power bus-bar mutual-throw device according to claim 1, characterized in that: the controller CU latches when it detects the following conditions: a) the switch position is abnormal (the incoming line 1, the incoming line 2 switch and the bus coupler switch are all on or off, and a locking signal is sent out after 30S delay; the PT disconnecting switch is not closed, and the delay time is 0.5S to send a locking signal); b) backup power-off locking; c) PT disconnection locking; d) and (4) protecting and locking.
5. The dual-power bus-bar mutual-throw device according to claim 1, characterized in that: when the operating power supply is switched to the fault bus, the bus tie breaker DL3 is switched off in an accelerated mode.
6. The dual-power bus-bar mutual-throw device according to claim 1, characterized in that: when the working power supply circuit breaker is in a surreptitious trip, the auxiliary contact starting device of the working switch closes the bus-coupled circuit breaker DL3 when the switching condition is met.
7. The dual-power bus-bar mutual-throw device according to claim 1, characterized in that: the power failure includes: loss of voltage, undervoltage, overvoltage, and phase loss.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
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| CN201911097251.5A CN110752664A (en) | 2019-11-11 | 2019-11-11 | Dual-power-supply fast switching device |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201911097251.5A CN110752664A (en) | 2019-11-11 | 2019-11-11 | Dual-power-supply fast switching device |
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| CN110752664A true CN110752664A (en) | 2020-02-04 |
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| CN201911097251.5A Withdrawn CN110752664A (en) | 2019-11-11 | 2019-11-11 | Dual-power-supply fast switching device |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111711261A (en) * | 2020-07-02 | 2020-09-25 | 陕西榆林能源集团横山煤电有限公司 | Method for manually switching factory power supply to different network power supply and automatically judging |
| CN112701776A (en) * | 2020-12-17 | 2021-04-23 | 广州发展电力科技有限公司 | Power supply fast switching system |
| US20240171172A1 (en) * | 2022-11-18 | 2024-05-23 | Star Technologies, Inc. | Switch protection system and switch protection method |
-
2019
- 2019-11-11 CN CN201911097251.5A patent/CN110752664A/en not_active Withdrawn
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111711261A (en) * | 2020-07-02 | 2020-09-25 | 陕西榆林能源集团横山煤电有限公司 | Method for manually switching factory power supply to different network power supply and automatically judging |
| CN112701776A (en) * | 2020-12-17 | 2021-04-23 | 广州发展电力科技有限公司 | Power supply fast switching system |
| US20240171172A1 (en) * | 2022-11-18 | 2024-05-23 | Star Technologies, Inc. | Switch protection system and switch protection method |
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Application publication date: 20200204 |