CN207218249U - An intelligent balanced voltage regulation and harmonic elimination comprehensive treatment device - Google Patents

Abstract

The utility model discloses a kind of intelligent balance pressure regulation harmonic elimination comprehensive treatment device, including：Master controller, its voltage sampling port are connected to the power taking pressure side of three phase network, and current acquisition end connects the obtaining current end of three phase network；Voltage regulating module, three voltage regulating modules access a phase line of the three phase network by the first A.C. contactor respectively, and first A.C. contactor is connected with the master controller；And static reacance generator, its sampling end are connected with the master controller, regulation output end accesses the three phase network.The utility model pin uses new logic control system and structure, realizes and carries out comprehensive intelligent improvement to taiwan area three-phase imbalance, taiwan area end low-voltage, two-way dynamic compensation output, harmonic wave interference.

Description

An intelligent balanced voltage regulation and harmonic elimination comprehensive treatment device

technical field

The utility model relates to the technical field of low-voltage electric energy quality comprehensive treatment, in particular to an intelligent balanced voltage regulation and harmonic elimination comprehensive treatment device.

Background technique

In the power system, the three-phase unbalance degree of the low-voltage station area is an important index to measure the management technology level of the low-voltage station area, and it also reflects the loss of the station area from the side. In addition, the quality of the terminal also affects the quality of electricity used by residents. Due to the development of our country's industrialization and the improvement of people's living standards, various electrical equipment and household appliances are common and complex. The increase in inductive loads and the use of nonlinear loads make the power factor low and the harmonic content increase. Load, seasonal load changes, power supply radius, load distribution and other factors will often cause large changes in line voltage. Too low voltage will cause insufficient output or abnormal operation of equipment, and too high voltage will affect the performance of electrical equipment. Safety. Although at the beginning of the design of the station area, due to the unreasonable load distribution and the uncertainty of the user's power consumption behavior, there will be a serious three-phase imbalance problem, and the three-phase imbalance will cause the distribution transformer and line loss to increase. Voltage quality and three-phase load balance is an important rigid index for the current assessment of the power grid company, and it is also an urgent matter for all sub-bureaus.

For the three-phase unbalanced regulation, currently the main methods are manual load adjustment and automatic phase change switch. Among them, the efficiency of manual phase modulation is low, and it is necessary to cut off the power in the station area, which affects the electricity consumption of residential users. Moreover, due to the uncertainty of user power consumption, manual phase modulation cannot be performed frequently, and the effect is not ideal; Relatively high, the installation point must be selected in a three-phase four-wire system, but most of the station areas are single-phase lines, and the actual number of phase changes of the phase change switch is very small, no more than 3 times a day, and the response to frequent unbalances is lagging , the effect is not ideal.

The low-voltage line automatic voltage regulator is a low-voltage control device specially designed for areas with long line power supply radius, thin line diameter and large line voltage loss on the market. It is mainly composed of compensation transformer, controller, contactor, etc. When the line voltage is too low, the controller controls the action of the contactor to switch the compensation transformer to compensate and boost the line voltage.

The low-voltage line automatic voltage regulator can effectively solve the low-voltage problem, but it can't do anything about three-phase unbalance control, reactive power compensation, and harmonic control. In addition, the three-phase imbalance will cause the neutral point of the line in the station area to shift, and the voltage of one phase with a lighter load will be too high. In severe cases, the three-phase voltage regulator will enter the overvoltage protection state, which will greatly affect the three-phase voltage regulator pressure regulation effect.

The information disclosed in this background section is only intended to increase the understanding of the general background of the present invention, and should not be considered as an acknowledgment or in any form to imply that the information constitutes the prior art already known to those skilled in the art.

Utility model content

The purpose of the utility model is to provide an intelligent balanced voltage regulation and harmonic elimination comprehensive treatment device, so as to overcome the disadvantages that the three-phase unbalance degree and low voltage in the low-voltage station area cannot be solved at the same time.

In order to achieve the above purpose, the utility model provides an intelligent balanced voltage regulation and harmonic elimination comprehensive treatment device, including: a main controller, the voltage sampling end of which is connected to the voltage acquisition end of the three-phase power grid, and the current acquisition end is connected to the three-phase power grid A current-taking terminal; a voltage regulating module, three of which are respectively connected to a phase line of the three-phase power grid through a first AC contactor, and the first AC contactor is connected to the main controller; and Static var generator, its sampling end is connected with the main controller, and the adjustment output end is connected to the three-phase power grid.

Preferably, in the above technical solution, the voltage regulation module is a compensation transformer, the input ends of the three compensation transformers are connected in series to a phase line of the three-phase power grid, and the adjustment ends are connected in parallel to the three-phase power grid through the first AC contactor. The same phase wire of the grid.

Preferably, in the above technical solution, the adjustment terminal of the compensation transformer is provided with several adjustment gears, and each of the adjustment gears is connected to a phase line of the three-phase power grid through a second AC contactor, wherein the The second AC contactor is connected to the output end of the main controller.

Preferably, in the above technical solution, the static var generator includes: a PWM signal generator whose input end is connected to the output end of the main controller; and a three-phase inverter bridge whose control end is connected to the PWM signal generator The output end of the signal generator is connected, and the output end is connected to the three-phase grid.

Preferably, in the above technical solution, the model of the main controller is YY-DVS-220C.

Preferably, in the above technical solution, there are multiple static var generators.

Compared with the prior art, the utility model has the following beneficial effects:

The intelligent balanced voltage regulation and harmonic elimination comprehensive treatment device in the utility model integrates the functions of three-phase voltage regulation, unbalance regulation and compensation through the technology of line voltage regulator and SVG. Increase or decrease the voltage of each phase to keep the voltage within the standard qualified voltage range, and it can also calculate the three-phase unbalance in the station area in real time, and finally adjust the balance state with the inverter to realize the voltage regulation of the terminal line and the three-phase unbalance in the station area The adjusted power quality comprehensive management technology can effectively regulate the voltage of low-voltage lines and accurately adjust the balance platform area in real time. It is another subsidy technology for existing power quality management.

Description of drawings

Fig. 1 is a structural schematic diagram of an intelligent balanced voltage regulation and harmonic elimination comprehensive treatment device according to the utility model.

Fig. 2 is a circuit connection diagram of the intelligent balanced voltage regulation and harmonic elimination comprehensive treatment device according to the utility model.

Detailed ways

The specific embodiments of the present utility model will be described in detail below in conjunction with the accompanying drawings, but it should be understood that the protection scope of the present utility model is not limited by the specific embodiments.

Unless expressly stated otherwise, throughout the specification and claims, the term "comprise" or variations thereof such as "includes" or "includes" and the like will be understood to include the stated elements or constituents, and not Other elements or other components are not excluded.

Fig. 1 to Fig. 2 have shown the structural representation of the intelligent balanced pressure regulating harmonic elimination comprehensive management device according to the preferred embodiment of the present invention.

As shown in Figure 1 and Figure 2, the intelligent balanced voltage regulation and harmonic elimination comprehensive treatment device includes: main controller, terminal line voltage regulation module and static var generator SVG-n (also called SVG module); the modules are connected by Carrier mode for communication, the device integrates three-phase voltage regulation, three-phase unbalance adjustment, reactive power compensation, online monitoring and other functions. The main controller is installed on the main outgoing line of the station area, and the SVG module is installed at the end of the three-phase unbalanced branch circuit. After the three-phase branch circuit is balanced, the final total output of the station area is balanced. The line voltage regulation module is installed at the place where the terminal voltage is low. For the specific system block diagram, see figure 1. Specifically, referring to Fig. 2, the voltage sampling terminal of the main controller is connected to the voltage-taking terminal of the three-phase power grid, and the current collecting terminal TA is connected to the current-taking terminal of the three-phase power grid. In this embodiment, the model selected by the main controller is YY -DVS-220C, TA is a current transformer, which is used to detect the current value; the voltage regulation module is a compensation transformer TB, which is used to compensate for boosting, and the input terminals of the three compensation transformers TB are connected in series to a phase line of the three-phase grid , the adjusting end is respectively connected in parallel to the same phase line of the three-phase grid through the first AC contactor KM-A, KM-B, KM-C, and the compensation transformer TB combines the DC control AC contactor KM-A, KM-B, KM-C, directly controlled by the main controller, is used to control the operation and bypass switching of each compensation transformer; furthermore, the adjustment terminal of the compensation transformer TB is equipped with several adjustment gears, and each adjustment gear is passed through a first The two AC contactors KM11, KM12, and KM13 are connected to one phase line of the three-phase power grid, and are used to switch the compensation gears of each compensation transformer. It is directly controlled by the main controller, which is used to control the switching of each compensation transformer TB and switch the compensation gear of each compensation transformer.

Continuing to refer to Figure 2, the static var generator SVG-n includes: a PWM signal generator and a three-phase inverter bridge; the input end of the PWM signal generator is connected to the output end of the main controller; the control end of the three-phase inverter bridge It is connected to the output terminal of the PWM signal generator, and the output terminal of the three-phase inverter bridge (that is, the adjustment output terminal of the static var generator) is connected to the three-phase power grid; among them, the static var generator SVG-n can be set to multiple , mainly through the inverter principle, the AC power is first converted into a DC power source, and then the DC power source is redistributed and inverted into AC.

Next, the three-phase voltage regulation, three-phase unbalance adjustment, reactive power compensation, online monitoring and other functions in this embodiment are described in detail:

Combined with Figure 2, the principle of voltage regulation is: when any one or more phases of the three phases A, B, and C are detected to be too low in input voltage, the main controller will automatically control the action of the first AC contactor corresponding to each phase, and will compensate the transformer input, and by controlling the action of the second AC contactor, adjust the compensation gear, so that the output voltage reaches the national standard qualified voltage; when the input voltage returns to the national standard qualified voltage, control the action of the first AC contactor, cut off the compensation transformer, adjust Compression module bypass. For example, when the input voltage U of phase A is low in a certain period of time, the main controller controls the first AC contactor KM-A to act and puts the compensation transformer TBa into operation. At this time, the main coil ax of the compensation transformer will generate a superimposed compensation voltage △Ua Into the A-phase line, the output voltage Uao is increased. When Uao still does not reach the qualified voltage after boosting, the main controller controls the action of KM11, switches the compensation gear, and increases △Ua, and finally the output voltage Uao rises to qualified voltage.

The principle of three-phase unbalance compensation is: the three-phase unbalance intelligent compensation device is a combination of various technologies such as IGBT technology, SVG technology, and power electronics technology. Operating parameters such as phase voltage and three-phase current, calculate the unbalanced load between the three phases and the current to be compensated through model calculation, and then control the PWM signal generator to send a control signal to the internal IGBT according to the value set by the device to make the three-phase The inverter bridge produces a current signal that meets the requirements. The three-phase load balance adjustment device can analyze the load imbalance between the three phases according to the AC sampling of the sampling circuit at the moment of power-on. The main controller calculates the current value and phase to be compensated, and the PWM signal generator sends a PWM signal to the Driven by IGBT, a current signal that meets the requirements is generated by the three-phase inverter bridge and sent to the system to achieve three-phase load balance regulation.

The principle of bidirectional dynamic reactive power tracking compensation is: the device can use the remaining device capacity after adjusting the three-phase unbalance to realize inductive and capacitive bidirectional dynamic reactive power tracking compensation. The controller DSP calculates to analyze the reactive power content of the load current, and then controls the PWM signal generator to output the PWM signal to the IGBT drive circuit according to the set compensation range, so that the three-phase inverter bridge generates a power equal to the system reactive component. , The reactive current with the opposite direction is connected to the system, so as to achieve the purpose of real-time dynamic tracking and compensation of reactive power. The closed-loop response time of dynamic reactive power compensation is required to be less than 10ms, and bidirectional fine compensation of power factor can be realized.

The principle of online monitoring is: the main controller can measure and count the operating parameters collected by the lower computer equipment through carrier communication, and interact with the data of the remote server system through GPRS to realize the online monitoring function of distribution transformers, mainly including:

① Collect three-phase voltage and current to realize the measurement of voltage, current, active power, reactive power, power factor and unbalance;

②Daily action times, total action times, current gear of the pressure regulating module, and statistics of the action time of each gear;

The principle of overload and short-circuit protection is as follows: Molded case circuit breakers and miniature circuit breakers can be installed in the intelligent balance voltage regulating device in the station area, and at the same time, miniature circuit breakers are installed in each static var generator. , the corresponding miniature circuit breaker or molded case circuit breaker is broken to achieve the protection function. When an overload or short circuit occurs in the voltage regulation and commutation main control device, the main controller will control the main contactors KM-A, KM-B, and KM-C to operate according to the set protection parameters, and switch the voltage regulation module to the side road status to protect the safety of the device.

The principle of lightning protection is: lightning arresters can be installed in the distribution box to effectively prevent damage caused by lightning overvoltage and operating overvoltage. If an overvoltage is encountered, the arrester conducts and introduces an inrush current into the grounded system.

To sum up, compared with the traditional line voltage regulator, the intelligent balance voltage regulator in the station area has added the three-phase unbalance adjustment function. By controlling the SVG module, it can accurately and quickly invert and adjust the unbalance degree of the station area, so that the transformer in the station area can run in the best unbalanced state. After the three-phase unbalance is improved, the neutral point offset disappears, which further improves the output of the transformer, effectively prevents the single-phase overload of the transformer, ensures the stable operation of the transformer, and improves the operation safety of the power system.

At the same time, the intelligent balanced voltage regulating device in the station area has added SVG two-way dynamic reactive power output, through two-way dynamic output, it can effectively solve the problem of low voltage over-compensation or under-compensation caused by the current power increase, as well as the problem of backward capacitor switching. Bi-directional dynamic real-time accurate output makes the output power close to 0.99, thereby reducing the current reactive component of the line, reducing the loss on the line and distribution transformer, and improving the power factor of the power supply system and the actual output of the distribution transformer.

Finally, the intelligent balance and voltage regulating device in the station area is connected in parallel to the main line, which solves the problem that some commutation switches change quickly and irregularly, and also makes up for a gap in the use of commutation switches, which can be reversed in real time according to the line load. Redistribution does not require power failure, and the response time is less than 5ms, which does not affect the normal operation of the user's electrical equipment.

The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. These descriptions are not intended to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the present invention and its practical application, so that those skilled in the art can realize and utilize various exemplary embodiments of the present invention and various Different options and changes. It is intended that the scope of the invention be defined by the claims and their equivalents.

Claims (6)

1. A comprehensive treatment device for intelligent balance voltage regulation and harmonic elimination, characterized in that it includes: The main controller, the voltage sampling terminal is connected to the voltage-taking terminal of the three-phase power grid, and the current collecting terminal is connected to the current-taking terminal of the three-phase power grid; A voltage regulating module, three of which are respectively connected to one phase line of the three-phase grid through a first AC contactor, and the first AC contactor is connected to the main controller; and Static var generator, its sampling end is connected with the main controller, and the adjustment output end is connected to the three-phase power grid. 2. The comprehensive treatment device for intelligent balanced voltage regulation and harmonic elimination according to claim 1, wherein the voltage regulation module is a compensation transformer, and three input terminals of the compensation transformer are connected in series to a phase line of a three-phase power grid , and the regulating ends are respectively connected in parallel to the same phase line of the three-phase power grid through the first AC contactor. 3. The intelligent balanced voltage regulation and harmonic elimination comprehensive treatment device according to claim 2, characterized in that, the adjustment end of the compensation transformer is provided with several adjustment gears, and each of the adjustment gears is passed through a second AC The contactor is connected to one phase line of the three-phase grid, wherein the second AC contactor is connected to the output end of the main controller. 4. The comprehensive treatment device for intelligent balance voltage regulation and harmonic elimination according to claim 1, wherein the static var generator comprises: a PWM signal generator, the input of which is connected to the output of the main controller; and The control terminal of the three-phase inverter bridge is connected to the output terminal of the PWM signal generator, and the output terminal is connected to the three-phase grid. 5. The comprehensive treatment device for intelligent balance voltage regulation and harmonic elimination according to claim 1, characterized in that the model of the main controller is YY-DVS-220C. 6. The intelligent balanced voltage regulation and harmonic elimination comprehensive treatment device according to claim 1, characterized in that there are multiple static var generators.