CN106026185A - Three-level subway energy feedback and harmonic control integrated device and control method thereof - Google Patents

Abstract

The invention discloses a three-level subway energy feedback and harmonic control integrated device and its control method, wherein the integrated device includes an integrated power converter and a control system connected in sequence, and the DC power of the integrated power converter The side casting is hung between the positive and negative busbars of the DC catenary in the subway power supply network, and the AC side of the integrated power converter is three-phase, respectively connected to the three-phase line of the low-voltage side of the rectifier transformer of the AC grid in the subway power supply network . Through a set of integrated devices, the smooth switching between the two working modes of subway energy feedback and harmonic control is realized, which not only makes full use of the braking energy of the subway, but also takes into account harmonic control; it uses three-level inverter technology to directly feed back regenerative energy To the low-voltage side of the traction rectifier transformer, there is no need for a feedback transformer, which can greatly reduce the cost of energy feedback devices; and use intelligent identification of subway operating conditions and detection of harmonic currents to complete the control of harmonic pollution on the AC side of the subway power supply network.

Description

Three-level subway energy feedback and harmonic control integrated device and its control method

technical field

The present invention relates to a device and method for energy feedback and harmonic control, in particular to a three-level subway energy feedback and harmonic control integrated device and its control method, belonging to subway braking energy feedback and harmonic control technology field.

Background technique

In recent years, the subway has become an indispensable way for people to travel in big cities. As a means of transportation with large capacity and high speed, it plays a very important role in the construction of urban rail transit. The rapid development of urban rail transit has an increasing demand for electric energy, and at the same time puts forward higher requirements for power quality and efficiency.

The subway can effectively alleviate the transportation pressure of urban traffic, and at the same time reduce the exhaust pollution and other problems; but it also brings many other problems, because the distance between subway stations is short, the locomotive brakes frequently, and the braking energy is very large, so The longer the braking distance of the subway, the longer the braking time. Generally, the subway will feed energy back to the power supply network when braking, but if the feedback energy cannot be fully utilized by other vehicles or electrical equipment, it will cause the grid voltage to pump up, and the pumped grid voltage will endanger the equipment in the station, which is not conducive to the subway safe operation. At the same time, the subway system mainly uses DC power supply. Its AC bus voltage is stepped down by the AC transformer, and then rectified by uncontrollable diodes to supply power for the subway traction. Some harmonic currents will inevitably be generated, and serious harmonic pollution will affect the city. The power quality of the rail transit power supply network will also cause problems such as increased power loss of the grid, shortened equipment life, and malfunction of grounding protection.

At present, the absorption devices used at home and abroad mainly include three types: resistive energy consumption type, energy storage type and low-voltage inverter feedback type.

The resistance energy consumption type uses the absorbing resistance to consume the energy generated during subway braking in the form of heat energy, which is the most common method at home and abroad. This method is mature and reliable, and it is convenient to control, but its main disadvantage is that the braking energy can only be consumed in the form of heat energy and cannot be used, resulting in energy waste, and the converted heat energy will cause the ambient temperature in the tunnel to rise. The corresponding ventilation device is added, which greatly increases the power loss. This kind of scheme is contrary to the theme of energy conservation and environmental protection, and does not meet the development requirements of lightweight subway.

The energy storage type is to absorb the braking energy in the energy storage device, and the energy storage device is generally a flywheel or a capacitor bank. When the subway train brakes, the kinetic energy is stored in the flywheel or capacitor bank; when the subway starts to accelerate and take the flow, the stored energy is released. The main disadvantage of the energy storage solution is that the energy storage device is not enough to completely absorb the braking energy, and the energy storage device is bulky, limited by the space of the subway, installation and maintenance are also very complicated, and the cost is too high.

The low-voltage inverter feedback type uses a three-phase inverter to invert the DC power generated during subway braking into power frequency AC power and feed it back to the 380V auxiliary AC power grid. However, due to the high instantaneous power during braking, the low-voltage inverter device cannot meet the requirements of rail transit.

In order to meet the requirements of energy saving and environmental protection, and make full use of regenerative energy, it is necessary to propose a new design scheme to overcome the defects of the above schemes.

Contents of the invention

The main purpose of the present invention is to overcome the deficiencies in the prior art, and provide a three-level subway energy feedback and harmonic control integrated device and its control method, which can not only perform energy feedback on subway train braking, but also Solving the problem of harmonic pollution in the subway power supply system and realizing the smooth switching of the two working modes of subway energy feedback and harmonic control has great industrial application value.

In order to achieve the above object, the technical scheme adopted in the present invention is:

A three-level subway energy feedback and harmonic control integrated device, including an integrated power converter and a control system connected in sequence, the DC side of the integrated power converter is connected to the DC catenary in the subway power supply network Between the positive and negative busbars, the AC side of the integrated power converter is three-phase, which is respectively connected to the three-phase line on the low-voltage side of the rectifier transformer of the AC grid in the subway power supply network.

Wherein, the integrated power converter is used to invert the connected braking energy when the subway is in the braking state and then feed it back to the AC power grid of the subway power supply network, that is, to run in the energy feedback mode, or when the subway is in normal operation When the harmonic current of the AC grid in the state and subway power supply network exceeds the standard, a reverse compensation current is generated to offset the harmonic current and compensate the distorted AC grid into a sine wave, that is, it operates in the harmonic control mode.

Moreover, the control system is used to control the integrated power converter to switch to the energy feedback mode and put into operation when the subway is in the braking state, or to switch to the The standby mode is suspended, or when the subway is in normal operation and the harmonic current of the AC grid in the subway power supply network exceeds the standard, it will automatically switch to the harmonic control mode and put into operation.

The present invention is further set as: the integrated power converter includes a three-level voltage inverter, a capacitor connected between the three-level voltage inverter and the DC catenary, and a capacitor connected to the three-level voltage inverter Filter between inverter and rectifier transformer.

The present invention is further set as: the three-level voltage type inverter includes three bridge arms distributed in parallel for a total of three phases, and each bridge arm includes four IGBT tubes, four freewheeling diodes and two clamps Bit diode; four IGBT tubes of each bridge arm are connected in series in sequence to form the upper bridge arm, middle bridge arm and lower bridge arm located in two adjacent IGBT tubes; the gate of the four IGBT tubes of each bridge arm The poles are evenly connected to the driving end of the control system, each freewheeling diode of each bridge arm is connected in reverse parallel to both ends of each IGBT tube, and the two clamping diodes of each bridge arm are connected in series in sequence and reversely Between the bridge arm and the lower bridge arm, the middle bridge arms of the three bridge arms are connected by wires.

The present invention is further configured as follows: the capacitor includes a first capacitor and a second capacitor connected in series in sequence, the first capacitor and the second capacitor are connected in parallel with the three bridge arms after being connected in series, and one end of the first capacitor is connected to the positive bus bar of the DC catenary The other end of the first capacitor is connected between the two clamping diodes, one end of the second capacitor is connected to the other end of the first capacitor, and the other end of the second capacitor is connected to the negative bus of the DC catenary.

The present invention is further set as: the filter includes a first inductance, a second inductance and a third inductance, one end of the first inductance, the second inductance and the third inductance are respectively connected to the middle bridge arm of the three bridge arms, and the first The other ends of the inductance, the second inductance and the third inductance are respectively connected to the three-phase lines on the low-voltage side of the rectifier transformer.

The present invention is further configured as follows: the control system includes a controller, a PWM generator and a drive module connected in sequence, and an A/D sampling module and an I/O circuit for two-way communication with the controller.

Wherein, the A/D sampling module is used to collect data and transmit the collected data to the controller; wherein, the collected data includes the voltage of the DC catenary, the current and harmonic current of the low-voltage side of the AC grid, and the integrated The AC signal of the power converter; the controller is used to receive the collected data and perform data processing to obtain the real-time working condition of the subway and output a real-time control signal; wherein, the real-time working condition of the subway includes braking state, no harmonic current In the normal operation state and the normal operation state with harmonic current, the real-time control signals include energy feedback signal, standby pause signal and harmonic control signal.

Moreover, the PWM generator is used to generate a corresponding PWM modulation wave according to the real-time control signal output by the controller; the driving module is used as the driving end of the control system to amplify the PWM modulation wave generated by the PWM generator, and The amplified PWM modulation wave is transmitted to the control terminal of the integrated power converter to drive the integrated power converter into operation; the I/O circuit includes an input circuit and an output circuit, and the input circuit is used to receive the input signal and convert the input signal The high level is converted into a low level input controller, and the output circuit receives the control signal of the controller and converts the low level of the control signal into a normal working voltage signal for output.

The present invention is further set as: the control system also includes a communication module connected to the controller, the communication module is used to establish communication between the controller and the upper computer; the controller includes a DSP main controller using a DSP chip and a The FPGA auxiliary controller of the FPGA chip, the DSP main controller and the FPGA auxiliary controller are connected in sequence, and are respectively connected with the A/D sampling module; the DSP main controller is used for data processing and then judges the real-time working condition and selection control of the subway signal; the FPGA auxiliary controller is used for logic processing and then generates a PWM waveform.

The present invention also provides a control method for a three-level subway energy feedback and harmonic control integrated device, including the following steps:

1) The system sets the trigger voltage of the DC catenary, detects the DC catenary voltage in real time through the A/D sampling module in the control system, and the controller in the control system compares the collected DC catenary voltage with the trigger voltage set by the system Compare and judge whether the DC catenary voltage is greater than the trigger voltage;

If so, it is judged that the real-time working condition of the subway is the braking state, and then step 2 is executed;

If not, then perform step 3);

2) The controller starts the energy feedback algorithm, generates energy feedback modulation waves, outputs energy feedback signals through the PWM generator and the drive module, and sends the energy feedback signals to the integrated power converter to be put into operation in energy feedback mode. The connected braking energy is fed back to the AC power grid of the subway power grid after inversion;

3) When the A/D sampling module detects the current reverse flow of the DC catenary in real time, the controller judges that the real-time working condition of the subway is normal operation;

Real-time detection of the current on the low-voltage side of the AC power grid through the A/D sampling module, and the controller judges whether the harmonic current exceeds the standard;

If yes, execute step 4);

If not, the controller immediately blocks the PWM pulse output, so that the integrated power converter enters the standby mode;

4) The controller starts the harmonic compensation algorithm, generates harmonic component modulation waves, outputs the actual compensation control signal through the PWM generator and the drive module, and the integrated power converter is put into operation, generating reverse compensation current to offset the harmonic current and will The distorted AC grid is compensated as a sine wave.

The control method of the present invention is further set to: the controller in the step 3) judges whether the harmonic current exceeds the standard, specifically,

3-1) The collected three-phase currents on the low-voltage side of the AC power grid are respectively ia, _ib and _ic , and through abc/ _dq coordinate transformation, the active current _{id and reactive current i q on} the low-voltage side of the AC power grid are obtained;

3-2) Active current i _d and reactive current i _q pass through a low-pass filter to leave a DC component, and then undergo coordinate inverse transformation to obtain three-phase fundamental currents i _af , i _bf and i _cf ;

3-3) Subtract the calculated three-phase fundamental wave current from the collected three-phase current at the low-voltage side of the AC power grid, and obtain the three-phase current harmonic components as i _ha , i _hb and i _hc ;

3-4) When the three-phase current harmonic components i _ha , i _hb and i _hc are greater than zero, it is judged that there is a harmonic current, and the degree of current distortion can be determined by comparing the fundamental wave value at the same time;

When the three-phase current harmonic components i _ha , i _hb and i _hc are equal to zero, it is judged that there is no harmonic current.

The control method of the present invention is further set to: the step 4) is specifically,

4-1) Perform PI regulation on the active current i _d and the active reference current I _d ^* on the low-voltage side of the AC grid, and perform PI adjustment on the real-time reactive current i _q and the reactive reference current I _q ^* on the low-voltage side of the AC grid, and then After dq/abc conversion and three-phase current harmonic components i _ha , i _hb and i _hc are calculated to obtain the modulation wave of the PWM modulation signal;

4-2) The controller calculates and generates the PWM waveform according to the modulation wave ratio of the PWM modulation signal, and outputs the actual compensation control signal through the PWM generator and the drive module, and the actual compensation control signal is output to the IGBT tube of the three-level voltage inverter, The reverse compensation current i _s , which is equal in size and opposite in direction to the harmonic current, is generated by turning on and off the IGBT tubes of each bridge arm, which is used to offset the harmonic current and compensate the distorted AC power grid into a sine wave.

Compared with prior art, the beneficial effect that the present invention has is:

1. Through the setting of a set of integrated devices, the present invention realizes the smooth switching of the two working modes of subway energy feedback and harmonic control in a set of devices, which can not only make full use of the braking energy of the subway, but also take into account the harmonic control and The function of reactive power compensation can filter the subway power supply network, which can serve multiple purposes.

2. The integrated device provided by the present invention adopts the three-level inverter technology, which can meet the needs of feeding back the braking energy of the subway to the medium-voltage power grid, while the traditional two-level technology can only feed back to the power grid of about 0.4kV; at the same time Since the regenerative energy is directly fed back to the low-voltage side of the traction rectifier transformer, there is no need for a feedback transformer, which can greatly reduce the cost of the energy feedback device; and there is no absorption resistor, and no energy storage device is required, making full use of the regenerative energy generated by subway braking, which is extremely efficient. The earth improves the energy utilization rate, and also improves the power quality problem.

3. The control method provided by the present invention can intelligently identify the operating conditions of the subway. Under the braking conditions of the subway, the control system starts the energy feedback module to complete the reuse of braking energy; when the subway is operating normally and there is a harmonic current , run the harmonic compensation algorithm, and complete the harmonic pollution control on the AC side of the subway power supply network.

The above content is only an overview of the technical solution of the present invention. In order to understand the technical means of the present invention more clearly, the present invention will be further described below in conjunction with the accompanying drawings.

Description of drawings

Fig. 1 is a schematic diagram of the electrical connection of the three-level subway energy feedback and harmonic control integrated device of the present invention;

Fig. 2 is the circuit diagram of the integrated power converter in the three-level subway energy feedback and harmonic control integrated device of the present invention;

Fig. 3 is a structural block diagram of the control system in the three-level subway energy feedback and harmonic control integrated device of the present invention;

Fig. 4 is a flow chart of the control method of the three-level subway energy feedback and harmonic control integrated device of the present invention;

Fig. 5 is a flowchart of harmonic compensation control in the control method of the three-level subway energy feedback and harmonic control integrated device of the present invention.

detailed description

Below in conjunction with accompanying drawing of description, the present invention will be further described.

The present invention provides a three-level subway energy feedback and harmonic control integrated device, as shown in Figure 1, including an integrated power converter 1 and a control system 2 connected in sequence, the DC The side casting is hung between the positive and negative busbars of the DC catenary in the subway power supply network, and the AC side of the integrated power converter 1 is three-phase, respectively connected to the low-voltage side three-phase line of the rectifier transformer of the AC grid in the subway power supply network superior.

The integrated power converter 1 is used to invert the connected braking energy when the subway is in the braking state and then feed it back to the AC power grid of the subway power supply network, that is, to run in the energy feedback mode, or when the subway is in normal operation When the harmonic current of the AC grid in the state and subway power supply network exceeds the standard, a reverse compensation current is generated to offset the harmonic current and compensate the distorted AC grid into a sine wave, that is, it operates in the harmonic control mode.

The control system 2 is used to control the integrated power converter 1 to switch to the energy feedback mode and put into operation when the subway is in the braking state, or to switch to the energy feedback mode when the subway is in normal operation and the AC power grid in the subway power supply network has no harmonic current. The standby mode is suspended, or when the subway is in normal operation and the harmonic current of the AC grid in the subway power supply network exceeds the standard, it will automatically switch to the harmonic control mode and put into operation.

A three-level subway energy feedback and harmonic control integrated device provided by the present invention, through the setting of the integrated power converter 1 and the control system 2, not only feeds back the braking energy of the subway to the medium-voltage power grid, but also The harmonics on the AC side of the power grid are compensated and treated, making full use of the regenerative braking energy of the subway, and also solving the power quality problems of the subway power supply system such as harmonic pollution and low power factor, so as to ensure the safe and reliable operation of subway trains.

As shown in Figure 2, the integrated power converter 1 includes a three-level voltage type inverter 3, a capacitor connected between the three-level voltage type inverter 3 and the DC catenary, and a capacitor connected to the three-level voltage type inverter 3. A filter between the flat voltage inverter 3 and the rectifier transformer.

The three-level voltage type inverter 3 includes three bridge arms distributed in parallel for a total of three phases, and each bridge arm includes four IGBT tubes, four freewheeling diodes and two clamping diodes; each The four IGBT tubes of the bridge arm are connected in series in sequence to form the upper bridge arm, the middle bridge arm and the lower bridge arm located in two adjacent IGBT tubes; the gates of the four IGBT tubes of each bridge arm are connected to the control system Each freewheeling diode of each bridge arm is anti-parallel connected to both ends of each IGBT tube, and the two clamping diodes of each bridge arm are serially connected in series and anti-parallel to the upper and lower bridge arms. Between the arms, the middle bridge arms of the three bridge arms are connected by wires.

Taking the first bridge arm as an example, it includes IGBT tubes VT ₁₁ , VT ₁₂ , VT ₁₃ and VT ₁₄ , freewheeling diodes VD ₁₁ , VD ₁₂ , VD ₁₃ and VD ₁₄ , and clamping diodes VD ₁ and VD ₂ . IGBT tubes VT ₁₁ , VT ₁₂ , VT ₁₃ and VT ₁₄ are connected in series in sequence to realize the switching on and off of the inverter branch; between VT ₁₁ and VT ₁₂ is the upper bridge arm, and between VT ₁₂ and VT ₁₃ is the middle bridge arm , between VT ₁₃ and VT ₁₄ is the lower bridge arm. Freewheeling diodes VD ₁₁ , VD ₁₂ , VD ₁₃ and VD ₁₄ are respectively connected in antiparallel with IGBT tubes VT ₁₁ , VT ₁₂ , VT ₁₃ and VT ₁₄ for turning off IGBT tubes VT ₁₁ , VT ₁₂ , VT ₁₃ and VT ₁₄ subsequent follow-up. Two clamping diodes VD ₁ and VD ₂ are connected in antiparallel between the upper bridge arm and the lower bridge arm to limit the switching voltage of IGBT tubes VT ₁₁ , VT ₁₂ , VT ₁₃ and VT ₁₄ to

The capacitor includes a first capacitor C ₁ and a second capacitor C ₂ connected in series in sequence. The first capacitor C ₁ and the second capacitor C ₂ are connected in parallel with the three bridge arms after being connected in series. One end of the first capacitor C ₁ is in contact with the DC The positive bus bar of the network is connected, the other end of the first capacitor _C1 is connected between _two clamping diodes VD1 and VD2, _one end of the _second capacitor C2 is connected to the other end of the first capacitor _C1 , and the second capacitor _The other end of C2 is connected to the negative busbar of the DC catenary.

The filter includes a first inductance L1, a second inductance L2 and a third inductance L3, one end of the first inductance L1, the second inductance L2 and the third inductance L3 are respectively connected to the middle bridge arm of the three bridge arms, the first The other ends of the inductor L1, the second inductor L2 and the third inductor L3 are respectively connected to the three-phase lines of the low-voltage side of the rectifier transformer.

As shown in Figure 3, the control system 2 includes a controller, a PWM generator and a drive module connected in sequence, an A/D sampling module and an I/O circuit for two-way communication with the controller, and a communication device connected to the controller. module; the controller includes a DSP main controller using a DSP chip and an FPGA auxiliary controller using an FPGA chip, the DSP main controller and the FPGA auxiliary controller are connected in sequence and are connected to the A/D sampling module respectively.

The A/D sampling module is used to collect data and transmit the collected data to the controller; wherein the collected data includes the voltage of the DC catenary, the current and harmonic current of the low-voltage side of the AC power grid, and the integrated power conversion AC signal of the device.

The controller is used to receive the collected data and perform data processing to obtain real-time working conditions of the subway and output real-time control signals; wherein, the real-time working conditions of the subway include braking status, normal operation status without harmonic current and harmonic current In the normal operating state of the current, the real-time control signals include energy feedback signals, standby pause signals and harmonic control signals. The DSP main controller is used for data processing to judge the real-time working conditions of the subway and select control signals; the FPGA auxiliary controller is used for logic processing to generate PWM waveforms.

The PWM generator is used to generate corresponding PWM modulation waves according to the real-time control signal output by the controller.

The driving module is used as the driving end of the control system to amplify the PWM modulation wave generated by the PWM generator, and transmit the amplified PWM modulation wave to the control end of the integrated power converter to drive the integrated power converter into operation.

The I/O circuit includes an input circuit and an output circuit, the input circuit is used to receive the input signal and convert the high level of the input signal into a low level input controller, the output circuit receives the control signal of the controller and converts the control signal The low level is converted to a normal working voltage signal output.

The communication module is used to establish communication between the controller and the upper computer.

The present invention also provides a control method for a three-level subway energy feedback and harmonic control integrated device, as shown in Figure 4, including the following steps:

1) The system sets the trigger voltage of the DC catenary, detects the DC catenary voltage in real time through the A/D sampling module in the control system, and the controller in the control system compares the collected DC catenary voltage with the trigger voltage set by the system Compare and judge whether the DC catenary voltage is greater than the trigger voltage;

If so, it is judged that the real-time working condition of the subway is the braking state, and then step 2 is executed;

If not, go to step 3).

2) The controller starts the energy feedback algorithm, generates energy feedback modulation waves, outputs energy feedback signals through the PWM generator and the drive module, and sends the energy feedback signals to the integrated power converter to be put into operation in energy feedback mode. The connected braking energy is fed back to the AC power grid of the subway power grid after inversion.

3) When the A/D sampling module detects the current reverse flow of the DC catenary in real time, the controller judges that the real-time working condition of the subway is normal operation;

Real-time detection of the current on the low-voltage side of the AC power grid through the A/D sampling module, and the controller judges whether the harmonic current exceeds the standard;

If yes, execute step 4);

If not, that is, the harmonic current G=0, the controller immediately blocks the PWM pulse output, so that the integrated power converter temporarily enters the standby mode.

Among them, the controller judges whether the harmonic current exceeds the standard, as shown in Figure 5, specifically,

3-1) The collected three-phase currents on the low-voltage side of the AC grid are i _a , i _b and i _c respectively, and through abc/dq coordinate transformation (box C32 shown in Figure 5), the currents on the low-voltage side of the AC grid are obtained active current i _d and reactive current i _q ;

3-2) The active current i _d and the reactive current i _q pass through the low-pass filter LPF to leave a DC component, and then undergo coordinate inverse transformation (shown as box C23 in Figure 5), to obtain the three-phase fundamental currents respectively be i _af , i _bf and i _cf ;

3-3) Subtract the calculated three-phase fundamental wave current from the collected three-phase current at the low-voltage side of the AC power grid, and obtain the three-phase current harmonic components as i _ha , i _hb and i _hc ;

3-4) When the three-phase current harmonic components i _ha , i _hb and i _hc are greater than zero, it is judged that there is a harmonic current G, and the degree of current distortion can be determined by comparing the fundamental wave value at the same time;

When the three-phase current harmonic components i _ha , i _hb and i _hc are equal to zero, it is judged that there is no harmonic current G.

4) The controller starts the harmonic compensation algorithm, generates harmonic component modulation waves, outputs the actual compensation control signal through the PWM generator and the drive module, and the integrated power converter is put into operation, generating reverse compensation current to offset the harmonic current and will The distorted AC grid is compensated as a sine wave.

As shown in Figure 5, step 4) is specifically,

4-1) Perform PI regulation on the active current i _d and the active reference current I _d ^* on the low-voltage side of the AC grid, and perform PI adjustment on the real-time reactive current i _q and the reactive reference current I _q ^* on the low-voltage side of the AC grid, and then After dq/abc conversion and three-phase current harmonic components i _ha , i _hb and i _hc are calculated to obtain the modulation wave of the PWM modulation signal;

4-2) The controller calculates and generates the PWM waveform according to the modulation wave of the PWM modulation signal, outputs the actual compensation control signal through the PWM generator and the drive module, and outputs the actual compensation control harmonic control signal to the IGBT of the three-level voltage inverter tube, using the switching on and off of the IGBT tubes of each bridge arm to generate a reverse compensation current i _s that is equal in magnitude to the harmonic current and opposite in direction, which is used to offset the harmonic current and compensate the distorted AC power grid into a sine wave.

The innovative point of the present invention is that a set of integrated devices realizes the smooth switching between the two working modes of subway energy feedback and harmonic control, which can not only make full use of the braking energy of the subway, but also take into account the function of harmonic control; it adopts three electric The flat inverter technology can meet the needs of feeding back the braking energy of the subway to the medium-voltage power grid, and directly feeds the regenerative energy back to the low-voltage side of the traction rectifier transformer without a feedback transformer, which can greatly reduce the cost of the energy feedback device; and adopts intelligent Identify the operating conditions of the subway and detect whether the harmonic current exceeds the standard. When the subway is operating normally and the harmonic current exceeds the standard, it will smoothly switch to the harmonic control mode to complete the harmonic pollution control on the AC side of the subway power supply network.

The above description is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Anyone familiar with this field Those skilled in the art, without departing from the scope of the technical solution of the present invention, may use the technical content disclosed above to make some changes or modify them into equivalent embodiments with equivalent changes. Technical Essence of the Invention Any simple modifications, equivalent changes and modifications made to the above embodiments still fall within the scope of the technical solutions of the present invention.

Claims (10)

1. a level subway energy feedback and harmonic wave control integrated apparatus, it is characterised in that: include The integrated power inverter being sequentially connected and control system, the DC side of described integration power inverter is thrown Hang in subway power supply net between the positive and negative bus of direct current contact net, the AC of integration power inverter For three-phase, it is connected in the low-pressure side triple line of the rectifier transformer of AC network in subway power supply net；

Described integration power inverter is for entering the braking energy accessed when subway is in on-position Feed back to the AC network of subway power supply net after row inversion, i.e. run on energy feedback pattern, or at subway In normal operating condition subway power supply net, the harmonic current of AC network produces Contrary compensation electricity when exceeding standard Flow to offset harmonic current and the AC network compensation of distortion is sine wave, i.e. runs on harmonic wave control mould Formula；

Described control system is used for controlling integration power inverter and switches to when subway is in on-position Energy feedback pattern puts into operation, or AC network in subway is in normal operating condition and subway power supply net In time without harmonic current, switches to standby mode and suspends, or is in normal operating condition and subway power supply net at subway The harmonic current of middle AC network automatically switches to harmonic wave control pattern and puts into operation when exceeding standard.

Three level subway energy feedbacks the most according to claim 1 and harmonic wave control integrated apparatus, It is characterized in that: described integration power inverter includes three-level VSI, is connected to three level Electric capacity between voltage source inverter and direct current contact net, and it is connected to three-level VSI and whole Wave filter between convertor transformer.

Three level subway energy feedbacks the most according to claim 2 and harmonic wave control integrated apparatus, It is characterized in that: described three-level VSI includes three brachium pontis of distribution in parallel connection of common three-phase, Each brachium pontis all includes four IGBT pipes, four fly-wheel diodes and two clamp diodes；

Four IGBT pipes of each brachium pontis are sequentially connected in series, and constitute and are positioned at dividing successively of adjacent two IGBT pipes The upper brachium pontis of cloth, bridge arm and lower brachium pontis；The equal connected control system of gate pole of four IGBT pipes of each brachium pontis Drive end, each fly-wheel diode of each brachium pontis is all connected anti-parallel to the two ends of each IGBT pipe, often Two clamp diodes of individual brachium pontis are connected anti-parallel between brachium pontis and lower brachium pontis after being sequentially connected in series, three bridges The bridge arm of arm is connected by wire.

Three level subway energy feedbacks the most according to claim 3 and harmonic wave control integrated apparatus, It is characterized in that: described electric capacity includes the first electric capacity and the second electric capacity being sequentially connected in series, the first electric capacity and second It is in parallel with three brachium pontis after capacitances in series, one end of the first electric capacity is connected with the positive bus-bar of direct current contact net, The other end of the first electric capacity is connected between two clamp diodes, one end of the second electric capacity and the first electric capacity The other end is connected, the other end of the second electric capacity is connected with the negative busbar of direct current contact net.

Three level subway energy feedbacks the most according to claim 3 and harmonic wave control integrated apparatus, It is characterized in that: described wave filter includes the first inductance, the second inductance and the 3rd inductance, the first inductance, One end of two inductance and the 3rd inductance bridge arm with three brachium pontis respectively is connected, the first inductance, the second inductance It is connected in the low-pressure side triple line of rectifier transformer with the other end of the 3rd inductance.

Three level subway energy feedbacks the most according to claim 1 and harmonic wave control integrated apparatus, It is characterized in that: described control system includes controller, PWM generator and the driving module being sequentially connected, And all with A/D sampling module and the I/O circuit of controller both-way communication；

Described A/D sampling module, for gathering data and the data of collection being transferred to controller；Wherein, Gather data include the voltage of direct current contact net, the electric current of AC network low-pressure side and harmonic current and The AC signal of integration power inverter；

Described controller, for receiving the data of collection and carry out data process, it is thus achieved that subway real-time working condition and Output real-time control signal；Wherein, subway real-time working condition includes on-position, transports without the normal of harmonic current Row state and the normal operating condition that there is harmonic current, real-time control signal includes energy feedback signal, treats Machine halt signal and harmonic wave control signal；

Described PWM generator, for generating corresponding PWM according to the real-time control signal of controller output Modulating wave；

Described driving module is as the drive end of control system, for amplifying the PWM that PWM generator generates Modulating wave, and the PWM ripple of amplification is transferred to the control end of integration power inverter to drive one Body power inverter puts into operation；

Described I/O circuit includes input circuit and output circuit, and input circuit is used for receiving input signal and inciting somebody to action The high level of input signal is converted to low level input controller, and output circuit receives the control signal of controller And the voltage signal that the low transition of control signal is normal work is exported.

Three level subway energy feedbacks the most according to claim 6 and harmonic wave control integrated apparatus, It is characterized in that: described control system also includes the communication module being connected with controller, described communication module is used Communicate in controller is set up with host computer；

Described controller includes the DSP master controller using dsp chip and uses the FPGA of fpga chip Pilot controller, described DSP master controller and FPGA pilot controller be sequentially connected and respectively with A/D Sampling module is connected；

Described DSP master controller processes for data and then judges subway real-time working condition and selects control signal； Described FPGA pilot controller is for logical process and then generates PWM waveform.

8. three level subway energy feedbacks and a control method for harmonic wave control integrated apparatus, its feature It is, comprises the following steps:

1) trigger voltage of default direct current contact net, real by the A/D sampling module in control system Time detection direct current contact net voltage, the controller in control system by gather direct current contact net voltage and system The trigger voltage set compares, and judges that whether direct current contact net voltage is more than trigger voltage；

The most then judge that subway real-time working condition is on-position, then perform step 2)；

If it is not, then perform step 3)；

2) controller starts energy feedback algorithm, generates energy feedback modulating wave, through PWM generator and Driving module output energy feedback signal, energy feedback signal sends into integration power inverter with energy feedback Pattern puts into operation, and integration power inverter feeds back to subway after the braking energy accessed is carried out inversion and supplies The AC network of electrical network；

3) the electric current adverse current of direct current contact net being detected in real time when A/D sampling module, controller judges subway Real-time working condition is normal operating condition；

Detected the electric current of AC network low-pressure side in real time by A/D sampling module, controller judges harmonic current Whether exceed standard；

The most then perform step 4)；

If it is not, then controller block at once pwm pulse output so that integration power inverter suspend into Enter standby mode；

4) controller starts harmonic compensation algorithm, generates harmonic component modulating wave, through PWM generator and Driving module to export actual compensating control signal, integration power inverter puts into operation, produces Contrary compensation The AC network of distortion is compensated as sine wave by electric current with counteracting harmonic current.

Three level subway energy feedbacks the most according to claim 8 and harmonic wave control integrated apparatus Control method, it is characterised in that: described step 3) in controller judge whether harmonic current exceeds standard, tool Body is,

The three-phase current of AC network low-pressure side 3-1) collected is respectively i_a、i_bAnd i_c, sit through abc/dq Mark conversion, obtains watt current i of AC network low-pressure side_dWith reactive current i_q；

3-2) watt current i_dWith reactive current i_qBy leaving DC component after low pass filter, then through sitting Mark inverse transformation obtains three-phase fundamental current and is respectively i_af、i_bfAnd i_cf；

3-3) three-phase current of the AC network low-pressure side collected is individually subtracted calculated three-phase base Ripple electric current, obtaining three-phase current harmonic component is i_ha、i_hbAnd i_hc；

3-4) when three-phase current harmonic component i_ha、i_hbAnd i_hcDuring more than zero, then judge to there is harmonic current, Contrast first-harmonic value simultaneously, it may be determined that current distortion degree；

When three-phase current harmonic component i_ha、i_hbAnd i_hcDuring equal to zero, then judge without harmonic current.

Three level subway energy feedbacks the most according to claim 9 and harmonic wave control integrated apparatus Control method, it is characterised in that: described step 4) specifically,

4-1) by watt current i of AC network low-pressure side_dWith meritorious reference current I_d ^*Carry out PI regulation, will The reactive power electric current i of AC network low-pressure side_qWith idle reference current I_q ^*Carry out PI regulation, then pass through With three-phase current harmonic component i after dq/abc conversion_ha、i_hbAnd i_hcIt is calculated the modulation of PWM modulation signal Ripple；

4-2) controller calculates according to the modulating wave of PWM modulation signal and generates PWM waveform, through PWM Generator and driving module export actual compensating control signal, and actual compensating control signal exports three level electricity The IGBT pipe of die mould inverter, utilizes the shutoff of opening of each brachium pontis IGBT pipe to produce and harmonic current size Contrary compensation electric current i equal, in opposite direction_s, it is used for offsetting harmonic current, the AC network of distortion is mended Repay as sine wave.