CN204732881U - The compensation arrangement that a kind of quality of power supply is energy-conservation - Google Patents

Abstract

The compensation arrangement that the quality of power supply of the present utility model is energy-conservation, comprises doubleization parallel-connection structure module and main control module; Doubleization parallel-connection structure module, comprises the first inversion module and the second inversion module; Two inversion modules are the identical and three phase full bridge voltage source type inverter be connected in parallel of rated output power; Main control module, comprises processor, programmable logic device, load current iL testing circuit and optical fiber transtation mission circuit; Load current iL testing circuit, is used for detecting the current i L flowing through load, and this detected value is exported to processor; Optical fiber transtation mission circuit, is used for the PWM drive singal that programmable logic device exports to export to each IGBT of doubleization parallel-connection structure module; Programmable logic device, the control command of receiving processor and complete the exchange with processor data; Processor, carries out computing by the electric current that load current iL testing circuit inputs, draws compensating instruction and export to programmable logic device.This device compensation efficiency is high, and stable performance, structure is simple.

Description

Compensation device for power quality and energy saving

【Technical field】

The utility model relates to the field of electric power equipment, in particular to an energy-saving compensation device composed of inverters with a dual parallel structure in the technical field of power transmission and distribution.

【Background technique】

Electric energy is the most widely used energy in modern society, and the quality of electric energy is related to all walks of life and people's daily electricity consumption, as well as the benefits of the national economy.

With the rapid development of industrial production and power electronic technology, electrical equipment and power electronic conversion devices are becoming more and more popular in iron and steel, metallurgy, petroleum, chemical and other industrial fields. The connection of nonlinear loads such as frequency conversion devices and rectifier devices injects A large number of electrical harmonics. Power harmonic interference causes electrical equipment abnormalities and accidents to increase year by year. Power system harmonics have become a "power public hazard" that threatens the safe operation of power systems and other power loads.

In public power grids and enterprise power grids, all electrical equipment connected to single-phase and three-phase AC power grids and working according to the principle of electromagnetic induction requires magnetizing current when establishing a magnetic field. Typical loads that consume useless power include asynchronous motors, transformers, discharge lamps, bare wires, and converters that regulate operation. Since most of the loads have inductive characteristics, these equipment and electrical appliances not only absorb active power from the power system, but also absorb magnetization energy to generate the necessary alternating magnetic field for the normal operation of these equipment and electrical appliances. The magnetizing current does not participate in energy conversion. The magnetizing current flows in a large amount in the system, which will increase the line loss and reduce the power quality, which will have adverse effects on power generation, power supply, and users. The waste of electric energy is a phenomenon that we do not want to appear. The magnetization energy caused by the appeal factor will increase the load on generators, transmission lines and transformers, resulting in losses and affecting the economy of the transmission and distribution system.

It can be seen that in the power system, the power factor is a very important indicator. If the power factor of the circuit is low, it means that the active power output by the power supply equipment (generating equipment) is less, which means that the energy generated by the power supply equipment is not enough. be fully utilized. To improve the utilization rate of the power supply, the power factor of the circuit must be improved. Because when the power supply voltage is constant, the higher the power factor, the smaller the current on the power supply line, and the smaller the heat loss on the line. Therefore, the power-saving transformation of the system must be carried out to eliminate these adverse effects.

As we all know, in the total useless consumption of distribution network below 10KV, the distribution transformer accounts for about 30%, and the low-voltage electrical equipment accounts for more than 65%. It can be seen that it is very necessary to improve the power factor in the low-voltage power distribution system. It has been proved from theoretical calculation and practice that the use of this kind of power-saving equipment has good economic effects and strong comprehensive functions, and it is an energy-saving measure worth promoting.

The power quality and energy saving comprehensive compensation system is a comprehensive compensation product specially developed for energy saving and power quality improvement. Using high-frequency power electronic switch conversion technology, analog and digital hybrid circuit technology; used for dynamic suppression of harmonics, compensation system zero-sequence harmonics, compensation system three-phase unbalance, voltage drop (sags), surge (surge), voltage Pulse (impulse) and instantaneous power supply interruption (outage) and fast compensation system demand for reactive power, suppress voltage fluctuations and flicker and enhance system stability. It is a comprehensive product that saves energy and improves various power quality problems. It has the advantages of fast response, continuous reactive power absorption, small harmonic current and low loss.

【Content of invention】

In view of this, the utility model provides a compensation device using a dual parallel structure for the needs of end users.

The utility model adopts the following technical scheme to construct a power quality and energy-saving compensation device, which includes a double parallel structure module and a main control module; a double parallel structure module, including a first inverter module and a second inverter module; two inverter modules It is a three-phase full-bridge voltage inverter circuit with the same rated output power and connected in parallel; the main control module includes a processor, a programmable logic device, a load current iL detection circuit and an optical fiber transmission circuit; the load current iL detection circuit uses To detect the current iL flowing through the load, and output the detection value to the processor, and its output terminal is connected to the I/O pin of the processor; the optical fiber sending circuit is used to output the PWM driving signal output by the programmable logic device to the Each IGBT of the dual parallel structure module has its input connected to the I/O pin of the programmable logic device, and its output terminal is connected to the gate of each IGBT of the double parallel structure module; the programmable logic device is connected to the processor for receiving and processing The control instruction of the device and the data exchange with the processor are completed; the processor calculates the current input by the load current iL detection circuit, obtains the compensation instruction and outputs it to the programmable logic device.

Preferably, the main control module further includes a first inverter module output current detection circuit and a second inverter module output current detection circuit; the first inverter module output current detection circuit is used to convert the detected first inverter The output current of each phase in the module is output to the processor, and the output current detection circuit of the second inverter module is used to output the detected output current of each phase in the second inverter module to the processor; the processor outputs the detected The currents output by the first inverter module output current detection circuit and the second inverter module output current detection circuit are compared with the current to be compensated to verify the compensation effect.

Preferably, the main control module also includes a three-phase AC voltage protection circuit, which is used to output the detected overvoltage, undervoltage, phase loss or phase sequence error protection signal of each phase of the AC voltage supplied to the load to the programmable The programmable logic device, the output end of which is connected to the I/O pin of the programmable logic device.

Preferably, the main control module further includes a three-phase AC voltage detection circuit, which is used to detect each phase of the AC voltage supplied to the load, and output the detection value to the processor, and its input terminal is connected to the three-phase AC voltage protection circuit The output terminal of the first-stage operational amplifier is connected to the I/O pin of the processor.

Preferably, the main control module also includes a bus voltage protection circuit, which is used to output the overvoltage protection signal of the detected voltage across the capacitor to the programmable logic device, and its output terminal is connected to the I/O of the programmable logic device pins.

Preferably, the main control module further includes a bus voltage detection circuit, which is used to detect the voltage at both ends of the capacitor, and outputs the detection value to the processor, and its input terminal is connected to the output terminal of the first stage operational amplifier of the bus voltage protection circuit , whose output is connected to the I/O pin of the processor.

Preferably, the main control module further includes a first inverter module output current protection circuit and a second inverter module output current protection circuit; the first inverter module output current protection circuit is used to convert the detected first inverter The overvoltage protection of the output current of each phase in the module is output to the programmable logic device, and its output terminal is connected to the I/O pin of the programmable logic device; the output current protection circuit of the second inverter module is used to convert the detected second The overvoltage protection of the output current of each phase in the inverter module is output to the programmable logic device, and its output terminal is connected to the I/O pin of the programmable logic device.

Preferably, the main control module further includes an optical fiber receiving circuit, which is used to receive a control signal input from an external terminal, and whose output terminal is connected to an I/O pin of a programmable logic device.

The beneficial technical effects of the utility model are: the power quality and energy-saving compensation device of the utility model fully utilizes the advantages of optical fiber communication such as high electrical insulation performance, strong anti-interference ability, large capacity, and high transmission quality, and combines optical fiber communication with dual parallel modules The application makes the compensation response fast, the compensation efficiency is high, and the performance is stable; compared with other compensation systems, the load current is directly calculated to calculate the compensation command, the system structure is simple, and the user cost is reduced.

【Description of drawings】

Fig. 1 schematic diagram of compensation principle;

The block diagram of the circuit structure of the compensation device for power quality and energy saving in Fig. 2 embodiment one;

The block diagram of the main control module circuit structure in Fig. 3 embodiment one;

The load current iL detection circuit circuit diagram of the compensation device for power quality and energy saving in Fig. 4 embodiment one;

The circuit diagram of the three-phase AC voltage protection circuit of the compensation device for power quality and energy saving in Fig. 5 embodiment one;

The circuit diagram of the three-phase AC voltage detection circuit of the compensation device for power quality and energy saving in Fig. 6 embodiment one;

The input circuit circuit diagram of the compensation device for power quality and energy saving in Fig. 7 embodiment one;

The circuit diagram of the output circuit of the compensation device for power quality and energy saving in Fig. 8 embodiment one;

The circuit diagram of the optical fiber transmission circuit of the compensation device for power quality and energy saving in Fig. 9 embodiment one;

Fig. 10 is a circuit diagram of the optical fiber receiving circuit of the compensation device for power quality and energy saving in Embodiment 1.

【Detailed ways】

In order to make the technical scheme and technical effect of this patent clearer, the specific implementation manner of this patent will be described in detail below in conjunction with the accompanying drawings and examples.

As shown in Figure 1, iL is the load current, iC is the uncompensated current, and iS is the current supplied by the power supply to the load. First, the compensation principle is outlined. The load current is calculated by the arithmetic circuit to obtain the fundamental component of the load current and the compensation current, such as the harmonic current of each order, the fundamental positive sequence reactive current, the fundamental negative sequence reactive current, the zero sequence current, the negative The signal is amplified by the compensation current generation circuit to obtain the compensation current, each harmonic current to be compensated in the compensation current and the load current, the fundamental positive sequence reactive current, and the fundamental negative sequence reactive current. Active current, zero-sequence current, negative-sequence active current and other currents have the same amplitude and opposite phases, so they can cancel each other out, and finally become a pure power supply current with only fundamental components.

Embodiment one:

As shown in Fig. 2 and Fig. 3, the compensation device for power quality and energy saving in the present embodiment includes a dualized parallel structure module and a main control module; in the main control module, the output ends of the following optical fiber transmission circuits are connected to each IGTB of the doubled parallel structure module the grid. The dual parallel structure module will compensate the current with the same amplitude and opposite phase according to the output of the main control module and the harmonic amplitude.

The dual parallel structure module includes the first inverter module and the second inverter module. The two inverter modules are three-phase full-bridge voltage type inverter circuits with the same rated output power and connected in parallel. The carrier wave of the two sets of inverter modules The difference is 180°, which realizes the dual parallel structure of two sets of inverter unit modules.

As shown in Figure 3, the main control module includes a processor, a programmable logic device, a load current i L detection circuit, a three-phase AC voltage protection circuit, a three-phase AC voltage detection circuit, a bus voltage protection circuit, a bus voltage detection circuit, and a first inverter Transformer module output current protection circuit, output current detection circuit of the first inverter module, output current detection circuit of the second inverter module, output current detection circuit of the second inverter module, input circuit, output circuit, optical fiber transmission circuit, optical fiber Receiver circuit, communication circuit, power supply circuit.

The load current iL detection circuit is used to detect the current iL flowing through the load, and output the detection value to the processor, and its output terminal is connected to the I/O pin of the processor. The load current iL detection circuit circuit is shown in Figure 4. This circuit is only the circuit of a certain phase of the three-phase load current, and the detection circuits of other phases are the same as this circuit. The current transformer connected to each phase line of the load filters the detected current through the first-stage operation IC36A, and then limits the current through the resistor R365, and the second-stage operational amplifier IC26A matches the input resistance, and IC26B amplifies it and outputs it to the processor.

The three-phase AC voltage protection circuit is used to output the detected overvoltage, undervoltage, phase loss or phase sequence error protection signals of each phase AC voltage supplied to the load to the programmable logic device, and its output terminal is connected to the programmable logic device. I/O pins of logic devices. The circuit of the three-phase AC voltage protection circuit is shown in Figure 5. This circuit is only for one phase of the three-phase AC, and the detection circuits for other phases are the same as this circuit. The voltage transformers connected to each phase of the three-phase AC filter the detected voltage through the first-stage operational amplifier IC32A, and then limit the current through the resistor R11. The input resistance of the second-stage operational amplifier IC1A is matched, and the subsequent multi-stage operational amplifiers After amplification, it is finally output to a programmable logic device through optocoupler isolation.

The three-phase AC voltage detection circuit is used to detect the AC voltage of each phase provided to the load, and output the detection value to the processor, and its input terminal is connected to the output terminal of the first-stage operational amplifier of the three-phase AC voltage protection circuit, and the output terminal Connect to the I/O pins of the processor. The circuit is shown in Figure 6, and its working principle is the same as that of the load current iL detection circuit, so it will not be repeated here.

The bus voltage protection circuit is used to output the overvoltage protection signal of the detected voltage across the capacitor to the programmable logic device, and its output terminal is connected to the I/O pin of the programmable logic device. Its circuit is the same as the one-phase circuit of the three-phase AC voltage protection circuit, and will not be repeated here.

The bus voltage detection circuit is used to detect the voltage at both ends of the capacitor and output the detected value to the processor. Its input terminal is connected to the output terminal of the first stage operational amplifier of the bus voltage protection circuit, and its output terminal is connected to the I/O of the processor. pins. Its circuit is the same as the one-phase circuit of the three-phase AC voltage detection circuit, and will not be repeated here.

The first inverter module output current protection circuit is used to output the detected overvoltage protection of each phase output current in the first inverter module to the programmable logic device, and its output terminal is connected to the I/O tube of the programmable logic device foot. Any one-phase circuit is the same as one-phase circuit of the three-phase AC voltage protection circuit, except that a current transformer is connected to any IGBT output end, and its working principle will not be repeated here.

The output current detection circuit of the first inverter module is used to output the detected output current of each phase in the first inverter module to the processor, and its input terminal is connected to the first-stage operational amplifier of the output current protection circuit of the first inverter module. The output terminal is connected to the I/O pin of the processor. Its circuit is the same as the one-phase circuit of the three-phase AC voltage detection circuit, and will not be repeated here.

The second inverter module output current protection circuit is used to output the detected overvoltage protection of each phase output current in the second inverter module to the programmable logic device, and its output terminal is connected to the I/O tube of the programmable logic device foot. Any one-phase circuit is the same as one-phase circuit of the three-phase AC voltage protection circuit, except that a current transformer is connected to any IGBT output end, and its working principle will not be repeated here.

The output current detection circuit of the second inverter module is used to output the detected output current of each phase in the second inverter module to the processor, and its input terminal is connected to the first-stage operational amplifier of the output current protection circuit of the first inverter module The output terminal is connected to the I/O pin of the processor. Its circuit is the same as the one-phase circuit of the three-phase AC voltage detection circuit, and will not be repeated here.

The input circuit is used to convert the strong current state signal of each electrical component in the power equipment into a weak current switch signal and output it to the programmable logic device, and its output terminal is connected to the I/O pin of the programmable logic device. Circuit diagram 7 is only one of the switch-in circuits, and the other switch-in circuits are the same as this circuit. The strong electric signal is limited by the resistor RD8 and then converted to "0" or "1" weak electric level by optocoupler isolation and output to the programmable logic device. .

The output circuit is used to convert the weak current control signal into a strong current signal and output it to an external electrical component. Its input terminal is connected to the I/O pin of the programmable logic device, and its output terminal is connected to the control terminal of the electrical component. The circuit diagram 8 is only one of the output circuits, and the other output circuits are the same as this circuit. The weak current switch signal "0" or "1" is driven by the integrated circuit module 75452 and then output by the optocoupler.

The optical fiber transmission circuit is used to output the PWM driving signal output by the programmable logic device to each IGBT of the dual parallel structure module, and its input end is connected to the I/O pin of the programmable logic device, and its output end is connected to the dual parallel structure module. Gate of each IGBT. Circuit diagram 9 is the driving circuit of two IGBTs, and the driving circuits of other IGBTs are the same as this circuit; the weak current switch signal "0" or "1" is driven by the integrated circuit module 75451 and then output by the optical fiber transmitter HFBR-1521.

The optical fiber receiving circuit is used to receive the control signal input by the external terminal, and its output terminal is connected to the I/O pin of the programmable logic device. The external terminal can be a computer, a touch screen terminal and other intelligent terminals. Its circuit diagram is shown in Figure 10, the optical fiber receiving model is HBRF-2521, and its working principle is opposite to that of the optical fiber transmitting circuit.

The communication circuit is used to communicate with the external terminal, one end is connected to the external terminal, and the other end is connected to the processor, including the RS232 communication circuit and the RS232 and RJ45 conversion circuit. The existence of the two circuits makes the communication of the compensation device compatible with the external terminal Better performance, can receive and send signals of various levels. The RS232 communication circuit adopts the typical application circuit of model MAX3223, and the RJ45 mutual conversion circuit adopts the typical application circuit of model ZNE-100TL. Because both circuits are typical application circuits, the circuit diagrams are not described in detail here.

The power supply circuit is used to convert the externally input DC voltage into the voltage required by other circuits or modules, and its output terminal is connected to the power supply pins of other circuits or modules. The circuit converts the 15V DC voltage input from the outside into 5V and 3.3V voltages, and is realized by using integrated modules in the prior art such as LM7805 and REF3030.

The programmable logic device receives the control instructions of the processor and outputs various received data to the processor, and the latter outputs instructions to the corresponding circuits according to its own logic, such as outputting corresponding PWM signals to the duplex according to the instructions of the processor. The IGBT in the parallel structure module realizes the compensation function; or outputs the corresponding output signal to the corresponding electrical component according to the detected protection signal, so as to realize the protection function. The programmable logic device is connected with the processor to exchange data with the processor, and its model is XC2S200E-7PQ208C.

The processor performs Fourier operation on the current input by the load current i L detection circuit to calculate the harmonic current, fundamental positive sequence reactive current, fundamental negative sequence reactive current, zero sequence current, negative sequence active current, etc. , and then output a compensation command to the programmable logic device according to the component to be compensated; compare the detected current output by the first inverter module and the second inverter module with the current to be compensated to verify the compensation effect; receive the external The input instruction is processed; it adopts the integrated circuit model TMS32028335.

The two sets of inverter modules work at the same time, which can reduce the daily loss of the inverter and improve the stability of the product; at the same time, the use of optical fiber communication has high electrical insulation performance, strong anti-interference ability, large capacity, high transmission quality, and fast response. Moreover, compared with compensation devices with other structures, the system in this embodiment has a simple structure and can reduce user costs.

The above descriptions are only preferred embodiments of this patent, and are not intended to limit this patent. For those skilled in the art, this patent may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this patent shall be included within the scope of protection of this patent.

Claims (8)

1. the compensation arrangement that the quality of power supply is energy-conservation, is characterized in that: it comprises doubleization parallel-connection structure module and main control module;

Doubleization parallel-connection structure module, comprises the first inversion module and the second inversion module; Two inversion modules are the identical and three phase full bridge voltage source type inverter be connected in parallel of rated output power;

Main control module, comprises processor, programmable logic device, load current iL testing circuit and optical fiber transtation mission circuit;

Load current iL testing circuit, is used for detecting the current i L flowing through load, and this detected value is exported to processor, the I/O pin of its output connection handling device;

Optical fiber transtation mission circuit, the PWM drive singal that programmable logic device exports is used for export to each IGBT of doubleization parallel-connection structure module, its input connects the I/O pin of programmable logic device, and its output connects the grid of each IGBT of doubleization parallel-connection structure module;

Programmable logic device, is connected with processor, the control command of receiving processor and complete the exchange with processor data;

Processor, carries out computing by the electric current that load current iL testing circuit inputs, draws compensating instruction and export to programmable logic device.

2. the compensation arrangement that the quality of power supply as claimed in claim 1 is energy-conservation, is characterized in that: described main control module also comprises the first inversion module output current detection circuit and the second inversion module output current detection circuit; First inversion module output current detection circuit, is used for phase output current every in the first inversion module detected to export to processor; Second inversion module output current detection circuit, is used for phase output current every in the second inversion module detected to export to processor; The first inversion module output current detection circuit that described processor will detect, the electric current that the second inversion module output current detection circuit exports and the electric current that will compensate compare, to verify compensation effect.

3. the compensation arrangement that the quality of power supply as claimed in claim 1 is energy-conservation; it is characterized in that: described main control module also comprises three-phase alternating current voltage protection circuit; it is used for the overvoltage being supplied to each cross streams voltage of load that will detect; under-voltage; phase shortage or phase sequence error protection signal export to programmable logic device, and its output connects the I/O pin of programmable logic device.

4. the compensation arrangement that the quality of power supply as claimed in claim 3 is energy-conservation; it is characterized in that: described main control module also comprises three-phase alternating voltage testing circuit; it is used for detecting each cross streams voltage being supplied to load; and this detected value is exported to processor; its input connects the output of three-phase alternating current voltage protection circuit first order amplifier, the I/O pin of output connection handling device.

5. the compensation arrangement that the quality of power supply as claimed in claim 1 is energy-conservation; it is characterized in that: described main control module also comprises busbar voltage protective circuit; it is used for the overvoltage protection signal of the electric capacity both end voltage detected to export to programmable logic device, and its output connects the I/O pin of programmable logic device.

6. the compensation arrangement that the quality of power supply as claimed in claim 5 is energy-conservation; it is characterized in that: described main control module also comprises busbar voltage testing circuit; it is used for the voltage at Detection capacitance two ends; and this detected value is exported to processor; the output of its input connection bus voltage protection circuit first order amplifier, the I/O pin of its output connection handling device.

7. the compensation arrangement that the quality of power supply as claimed in claim 2 is energy-conservation, is characterized in that: described main control module also comprises the first inversion module output current protective circuit and the second inversion module output current protective circuit; First inversion module output current protective circuit, is used for the overvoltage protection of phase output current every in the first inversion module detected to export to programmable logic device, and its output connects the I/O pin of programmable logic device; Second inversion module output current protective circuit, is used for the overvoltage protection of phase output current every in the second inversion module detected to export to programmable logic device, and its output connects the I/O pin of programmable logic device.

8. the compensation arrangement that the quality of power supply as described in as arbitrary in claim 1 to 7 is energy-conservation, it is characterized in that: described main control module also comprises optical receiving circuit, it is used for receiving the control signal of exterior terminal input, and its output connects the I/O pin of programmable logic device.