CN204304446U - The quick harmonics restraint reactive power compensator of a kind of intelligent integrated formula - Google Patents

Abstract

The utility model discloses an intelligent integrated fast harmonic suppression reactive power compensation device, which comprises a circuit breaker, an internal current transformer, a control unit, a switching compensation unit, and the switching compensation unit includes a thyristor module and a resistance-capacitance absorption circuit , Reactors, capacitors. One end of the circuit breaker is connected to the power grid, and the other end is connected to the internal current transformer and switching compensation unit; the thyristor module, reactor, and capacitor in the switching compensation unit are connected in sequence, and the control unit includes a thyristor drive circuit and a zero-crossing detection circuit. , Internal current detection circuit, temperature detection circuit, man-machine display panel, bus communication and level control signal input ports. The utility model is suitable for a three-phase power grid with frequent load changes, fast response speed, zero-crossing switching, no inrush current, no arcing, and can be re-injected without discharging, can suppress harmonic current and flicker current, and is suitable for frequent loads. The changing electrical equipment quickly provides the required reactive power compensation.

Description

An Intelligent Integrated Fast Harmonic Suppression Reactive Power Compensation Device

technical field

The utility model relates to a reactive power compensation device in the technical field of low-voltage distribution networks, in particular to an intelligent integrated fast harmonic suppression reactive power compensation device.

Background technique

The traditional composite switch switching inductance and capacitance reactive power compensation device adopts mechanical switch switching, the response speed is slow, the inrush current is large, and the action interval is long, that is, the next input action cannot be performed until the capacitor discharge is completed, and it cannot follow the load. The reactive current changes rapidly, so it is not suitable for power consumption sites where the load changes frequently. And when multiple reactive power compensation devices in the network are working in a network, there is only one control mode of bus communication between the master and slaves. In addition to the delay of the mechanical switch itself, the switching response speed is still affected by the bus communication delay. And when the bus communication is disturbed, the device cannot switch normally.

Utility model content

The technical problem to be solved by the utility model is to overcome the shortcomings of the prior art, and provide an intelligent integration with true zero-crossing switching, no inrush current, no overvoltage, no impact on capacitors and power grids, and faster switching response. Fast harmonic suppression reactive power compensation device.

In order to solve the above technical problems, the utility model provides an intelligent integrated fast harmonic suppression reactive power compensation device, which includes a control unit, the control unit includes a zero-crossing detection unit and a thyristor drive unit, and is characterized in that: it also includes A switching compensation unit, the switching compensation unit includes a first thyristor module, a second thyristor module, a first reactor, a second reactor, a third reactor and a corner capacitor; the first thyristor The anode terminal of the thyristor module is connected to the first phase line of the external three-phase power supply, the cathode terminal is connected in series with the first reactor, and the anode terminal of the second thyristor module is connected to the third phase line of the external three-phase power supply, The cathode terminal is connected in series with the second reactor, and the first, second and third reactors are connected in parallel to the delta capacitor, and the other end of the third reactor is connected to the second phase line of the external three-phase power supply; The anode and cathode of the first thyristor module are connected in parallel with a first resistance-capacitance absorption circuit, and the cathode and anode of the second thyristor module are connected in parallel with a second resistance-capacity absorption circuit.

The thyristor drive unit is connected to the control poles of the first thyristor module and the second thyristor module respectively, and the zero-crossing detection unit is connected to the cathode and anode poles of the first thyristor module and the second thyristor module Connect separately.

The technical scheme that the utility model is further limited is:

Further, a circuit breaker and an internal current transformer are connected in series between the switching compensation unit and the external three-phase power supply.

Further, the control unit further includes an internal current detection port, and the internal current detection port is connected to an internal current transformer.

Further, the control unit also includes a temperature detection port, a man-machine display port, a power port, and a bus communication and level control signal input port.

Further, the reactor, the delta capacitor, the first thyristor module and the second thyristor module have built-in temperature sensors, and the output signals of the temperature sensors are connected to the temperature detection port of the control unit.

Further, a reactor fan and a radiator fan are also included, and the fans are connected to the signal control port of the control unit.

Further, the single-chip microcomputer of the control unit adopts STM32F100RBT6 based on ARM platform.

The working principle of the utility model is: the comprehensive measurement and control device collects the voltage and current signals of the three-phase power grid, analyzes and calculates the reactive power deficit that needs to be compensated, outputs the switching control signal through the bus communication or level control output port, and sends it to the The control unit of the above-mentioned device; the zero-crossing detection circuit of the control unit detects the zero-crossing signal at both ends of the thyristor, and according to the switching control signal given by the comprehensive measurement and control device, determines the zero-crossing switching time, and sends the switching signal to To the thyristor drive circuit of the control unit; the thyristor drive circuit of the control unit outputs a trigger pulse signal according to the received control signal, and transmits the trigger pulse signal to the thyristor module of the switching compensation unit , to control the on-off of the thyristor module; the switching compensation unit outputs compensation current according to the on-off of the thyristor module, and the compensation current is delivered to the power grid through the circuit breaker.

The beneficial effect of the utility model is that: the integrated measurement and control device of the device is used together to realize intelligent networking, and can provide three control modes of bus, level and hybrid control, and the network can accommodate up to 32 reactive power compensation devices. When the utility model is used, for the three-phase power grid with frequent load changes, the response speed is fast, zero-crossing switching, no inrush current, no arcing, and can be re-injected without discharging, which can suppress harmonic current and flicker current, and provide The electrical equipment whose load changes frequently provides the required reactive power compensation quickly.

Description of drawings

Fig. 1 is a working principle diagram of the utility model.

Fig. 2 is a schematic diagram of the zero-crossing detection circuit in the control unit of the present invention.

Fig. 3 is a schematic diagram of the thyristor driving circuit in the control unit of the present invention.

Detailed ways

Example 1

An intelligent integrated fast harmonic suppression reactive power compensation device provided in this embodiment, as shown in Figure 1, includes a control unit and a switching compensation unit, and the control unit includes a thyristor drive unit, a zero-crossing detection unit, an internal Current detection port, temperature detection port (reactor, capacitor, thyristor, ambient temperature), man-machine display panel, bus communication and level control signal input port.

The switching compensation unit includes a first thyristor module, a second thyristor module, a first reactor, a second reactor, a third reactor and a corner capacitor.

Terminals A1 , K1 , and g1 of the first thyristor module, and terminals A2 , K2 , and g2 of the second thyristor module are respectively connected to the control signal terminal of the control unit. The A1 terminal of the first thyristor module is connected to the A-phase outgoing line of the circuit breaker, the K1 terminal is connected to the first reactor, the A1 terminal of the second thyristor module is connected to the C-phase outgoing line of the circuit breaker, and the K1 terminal is connected to the third reactor.

The silicon controlled rectifier driving circuit provides a driving pulse signal to the terminal g1 of the first silicon controlled silicon module and the terminal g2 of the second silicon controlled silicon module.

Terminals A1 and K1 of the first thyristor module and terminals A2 and K2 of the second thyristor module are respectively connected to the zero-crossing detection circuit of the control unit.

The internal current signal output by the internal current transformer is connected to the internal current detection circuit. The output signals of the reactor, the built-in temperature sensor of the capacitor, the temperature sensor of the thyristor and the ambient temperature sensor are connected to the temperature detection port. The bus communication circuit is connected to the communication terminals of the measurement and control device and other reactive power compensation devices, and the level control signal output by the measurement and control device is connected to the level control signal input port of the reactive power compensation device.

As shown in Fig. 2, the zero-crossing detection circuit in the control unit of the utility model takes the zero-crossing detection of the A-phase thyristor as an example, one end of R1 is connected to K1, the other end is connected to R2 and R3 in turn, and one end of R4 is connected to K2. The other end is connected to R5, R6 in turn, the other end of R3, R6 is connected to V1, the output end of V1 is connected to the input of N1, the output end of N1 is connected to the 3.3V power supply, and the other end is connected to the output zero-crossing signal Zero. Among them, terminals K1 and K2 are respectively connected to terminals A1 and K1 of the first thyristor module in the switching compensation unit, resistors R1~R6 act as current limiters, rectifier bridge stack V1 rectifies the sinusoidal voltage waveform into a half-wave, and the optocoupler N1 plays the role of isolation. When the voltages at both ends of K1 and K2 are equal, the optocoupler will be cut off, and the output will be at low level. Wave ability, good anti-interference ability. The zero-crossing switching of the capacitor needs to be judged according to the zero-crossing signal.

As shown in Figure 3, the thyristor drive circuit in the control unit of the utility model, taking the A-phase thyristor drive circuit as an example, A_CTRL is connected to R6, R7, Q3 in turn, and the output terminal 3 of Q3 is connected to R5, R5 The other end of Q2 is connected to Q2, R4, the output end 3 of Q2 is connected to R1, C2, R3 in turn, the other end of R1 is connected to Q1, the output end 2 of Q1 is connected to D3, Z1, the other end of Z1 is connected to T1, the two circuits of T1 The output terminals are respectively connected to D1, C1, R2, D2 and D4, C3, R2, D5, one end of D2 is connected to G1, the other end is connected to K1, one end of D5 is connected to G2, and the other end is connected to K2. The bidirectional thyristor module is driven by the pulse transformer T1 to trigger its conduction. The driving circuit part of the pulse transformer T1 is driven by the MOS tube Q1. A_CTRL is the trigger control signal port sent by the single-chip microcomputer. After the single-chip microcomputer is reset, A_CTRL is low. Transistor Q3 is not conducting, Q2 is not conducting, MOS tube Q1 is not conducting, to ensure that the pulse transformer does not work when the microcontroller is powered on, when A_CTRL is set to high level, triode Q3 is conducting, Q2 is also conducting, and MOS tube Q1 is conducting On, 12V voltage is applied to both ends of the pulse transformer to generate a trigger current and turn on the thyristor module. After the MCU receives the switching signal, it will send a driving pulse signal at the zero-crossing moment of the voltage to switch on the capacitor. The switching sequence is to switch on the C-phase thyristor first, and then turn on the A-phase thyristor module after judging that the C-phase has been switched on. .

When working, the primary current transformer collects the current signal of the power grid and transmits the current signal to the integrated measurement and control device. The integrated measurement and control device internally collects the voltage signal, analyzes and calculates the voltage and current signals, and obtains the reactive power deficit required for compensation. , and judge whether to switch the device according to the current reactive power and power factor.

When the current reactive power is greater than zero and the power factor is less than the target power factor, the integrated measurement and control device will give an input command, which will be sent to the control unit of the device through the bus communication port or the level control port; the zero-crossing detection circuit of the device control unit can detect The zero-crossing signal at both ends of the silicon controlled rectifier, and after receiving the input command given by the integrated measurement and control device, at the moment when the voltage crosses zero, a trigger pulse signal is sent to trigger the bidirectional thyristor module, and each half cycle triggers its conduction in turn. In this way, the switching compensation unit outputs compensation current, and the compensation current is delivered to the power grid through the circuit breaker, which compensates the reactive power shortage of the power grid and improves the power factor to the target power factor.

When the current reactive power is less than zero or the power factor is greater than the target power factor, the comprehensive measurement and control device will give a cutting command, which will be sent to the control unit of the device through the bus communication port or level control port; the thyristor drive circuit of the device control unit will be removed The pulse signal is triggered, the thyristor module of the switching compensation unit of the device is turned off, and the path of the capacitor and the reactor is cut off.

The single-chip microcomputer of the control unit of this embodiment adopts STM32F100RBT6 based on the ARM platform; the drive of the thyristor is driven by a pulse transformer to generate a trigger drive signal. Reliable triggering of SCRs.

In addition to the above embodiments, the utility model can also have other implementations. All technical solutions formed by equivalent replacement or equivalent transformation fall within the scope of protection required by the utility model.

Claims (7)

1. An intelligent integrated fast harmonic suppression reactive power compensation device, characterized in that: it includes a control unit and a switching compensation unit, and the control unit includes a zero-crossing detection unit and a thyristor drive unit; The switching compensation unit includes a first thyristor module, a second thyristor module, a first reactor, a second reactor, a third reactor and a corner capacitor; the anode of the first thyristor module The terminal is connected to the first phase line of the external three-phase power supply, the cathode terminal is connected in series with the first reactor, the anode terminal of the second thyristor module is connected to the third phase line of the external three-phase power supply, and the cathode terminal is connected to the second The reactors are connected in series, and the first, second and third reactors are connected in parallel to the delta capacitors, and the other end of the third reactor is connected to the second phase line of the external three-phase power supply; the first controllable The cathode and anode poles of the silicon module are connected in parallel with a first resistance-capacity absorption circuit, and the cathode and anode poles of the second thyristor module are connected in parallel with a second resistance-capacity absorption circuit; The thyristor drive unit is connected to the control poles of the first thyristor module and the second thyristor module respectively, and the zero-crossing detection unit is connected to the cathode and anode poles of the first thyristor module and the second thyristor module Connect separately. 2. The intelligent integrated fast harmonic suppression reactive power compensation device according to claim 1, characterized in that a circuit breaker and an internal current transformer are connected in series between the switching compensation unit and the external three-phase power supply. 3. The intelligent integrated fast harmonic suppression reactive power compensation device according to claim 2, characterized in that: the control unit further includes an internal current detection port, and the internal current detection port is connected to an internal current transformer. 4. The intelligent integrated fast harmonic suppression reactive power compensation device according to claim 1, characterized in that: the control unit also includes a temperature detection port, a man-machine display port, a power port, and bus communication and level control signals input port. 5. The intelligent integrated fast harmonic suppression reactive power compensation device according to claim 4, characterized in that: the reactor, the corner capacitor, the first thyristor module and the second thyristor module are built with temperature sensor, the output signal of the temperature sensor is connected to the temperature detection port of the control unit. 6. The intelligent integrated fast harmonic suppression reactive power compensation device according to claim 1, further comprising a reactor fan and a radiator fan, the fans are connected to the signal control port of the control unit. 7. The intelligent integrated fast harmonic suppression reactive power compensation device according to any one of claims 1-6, characterized in that: the single-chip microcomputer of the control unit adopts STM32F100RBT6 based on ARM platform.