CN206490597U - Power rectifier system - Google Patents

Abstract

The utility model discloses a power supply rectification system for a servo controller, which comprises a circuit breaker, a surge protector, an input reactor and an AC rectification unit connected in sequence; Open the connection between the power supply grid and the power rectification system; the surge protector is used to connect the power rectification system to the equipotential system when the surge occurs, and limit the voltage to protect the power rectification system; the input reactor is used for Reduce the current harmonics, limit the impact of the impact current generated by the abnormal fluctuation of the grid voltage on the power rectification system and the servo motor driver at the back end, and suppress the surge. The power supply rectification system used for the servo controller of the utility model can well protect the servo driver, especially the equipment from being impacted by strong lightning surge, and avoid the equipment from being burned out.

Description

Power rectification system

technical field

The utility model relates to the field of AC rectification, in particular to a power rectification system used for a servo controller.

Background technique

In order to make the input current on the grid side available for the servo controller, it is necessary to rectify and filter the input current of the grid. However, the existing rectification circuit cannot protect the servo drive well, especially when facing a strong lightning surge. There is a greater risk of burning out the device.

Utility model content

The utility model aims to overcome the above-mentioned shortcomings of the prior art, and provides a power rectification system for a servo controller that can well protect the servo drive, especially the equipment from strong lightning surges.

In order to realize above-mentioned utility model purpose, the technical scheme that the utility model adopts is:

A power rectification system for a servo controller, including a circuit breaker, a surge protector, an input reactor, and an AC rectification unit connected in sequence; the circuit breaker is used to disconnect the power supply network from the power supply when the input current is too large The connection of the rectification system; the surge protector is used to connect the power rectification system to the equipotential system when the surge is generated, to limit the voltage and protect the power rectification system; the input reactor is used to reduce the current harmonic , limit the impact of the impact current generated by the abnormal fluctuation of the grid voltage on the power rectification system and the servo motor driver at the rear end, and suppress the surge; the AC rectification unit is used to rectify the AC power of the grid.

Further, it also includes a residual current leakage protection device, which is connected to the circuit breaker and is used to disconnect the circuit breaker when it detects that the residual current in the input power rectification system exceeds the set value. The connection of the power supply grid to the power rectification system.

Further, a contactor is also included for controlling the working state of the servo controller.

Further, an electromagnetic compatibility filter is also included, connected between the surge protector and the input reactor, for reducing electromagnetic interference generated by the power rectification system and avoiding affecting other equipment in the power grid.

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

The power supply rectification system used for the servo controller of the utility model can well protect the servo driver, especially the equipment from being impacted by strong lightning surge, and avoid the equipment from being burned out.

Description of drawings

Figure 1 is a block diagram of a power rectification system module for a servo controller of the present invention.

Figure 2 is a block diagram of a surge protector module for a servo controller of the present invention.

detailed description

The utility model will be further described in detail below in conjunction with specific embodiments. However, it should not be understood that the scope of the above-mentioned themes of the present utility model is limited to the following embodiments, and all technologies realized based on the content of the present utility model belong to the scope of the present utility model.

Example 1:

A power rectification system for a servo controller, referring to Fig. 1, includes a circuit breaker 1, a surge protector 2, an input reactor 3, and an AC rectification unit 4 connected in sequence; the circuit breaker 1 is used for input current When it is too large, disconnect the connection between the power supply grid and the power rectification system; the surge protector 2 is used to connect the power rectification system to the equipotential system when the surge occurs instantly, limit the voltage, and protect the power rectification system The input reactor 3 is used to reduce the current harmonics, limit the impact of the impact current generated by the abnormal fluctuation of the grid voltage on the power rectification system and the servo motor driver at the back end, and suppress the surge; the AC rectification unit 4 is used for Rectifies the alternating current of the grid.

The main causes of surges are heavy equipment start-up, short-circuit power switching, or lightning strikes. When dealing with lightning strikes: the energy of lightning strikes is huge (the average duration is 5.5us, and the peak current is 150KA). It is necessary to gradually discharge the energy through the method of hierarchical discharge. into the earth. At the junction of the direct lightning protection zone (LPZ0) and the first protection zone (LPZ1) (such as the main distribution box), the installation needs to pass the type I test (the lightning current is greater than 100KA (the analog waveform is 10/350us), and the response time is less than 25ns. ) surge protector, which limits the surge voltage of hundreds of thousands of volts to within 2800V. In order to continue to discharge the residual voltage of the previous stage and the induced lightning surge voltage in the area, at the junction of the first protection zone (LPZ1) and the second protection zone (LPZ2) (such as distribution boxes), it is necessary to install a Class II The surge protector for the test (lightning current greater than 40KA (simulated waveform is 8/20us), response time less than 25ns) limits the surge voltage within 1500V. In the follow-up protection boundary (such as the electric cabinet of electrical equipment), it is necessary to install a surge protector that has passed the type II test (the lightning current is greater than 20KA (the analog waveform is 8/20us), and the response time is less than 25ns) to limit the surge voltage. Within 1000V. An overcurrent protection device (air switch or fuse) should be connected in series before the surge protector SPD to prevent SPD aging or short circuit from causing damage to the power supply system. Depending on the type of grid (such as TN-C grid, TN-S grid, TT grid, IT grid), different types of SPDs and connection methods should be selected, as shown in Figure 2 for the general wiring method, surge protection The distance between the device and the protected equipment should be less than 10m, and the distance between the overcurrent protection device and the surge protector should be less than 0.5m.

The power rectification system is not only a source of harmonic interference (generating current harmonics to affect the power grid), but also a source of harmonic interference (absorbing surge current caused by abnormal voltage fluctuations from the power grid). The function of the passive rectification input reactor: suppress the harmonic current generated by the power rectification system: the power rectification system of the utility model, the input AC grid voltage is a sine wave, but the input current is a 6-pulse square wave, according to the Fourier series Decomposition, the harmonic components mainly include 5th, 7th, 11th, 13th, 17th, 19th and other 6m ± 1 (m=1, 2, 3...) harmonics. It can better suppress the harmonic components of each order, reduce the harmonic current by 30%, and reduce the pollution to the power grid. Limit the impact of the inrush current generated by the abnormal fluctuation of the grid voltage on power components such as the power rectification system and the rear-end motor drive unit, and improve system reliability and service life. In general, the passive rectification input reactor is a necessary component, especially in the following occasions: the ratio of grid capacity to inverter capacity is above 10:1, or the power supply capacity is above 600KVA. In this case, when the large-scale electrical equipment in the power grid is turned off, due to the parasitic inductance on the line, huge power grid voltage fluctuations will occur. When the phase-to-phase voltage unbalance coefficient k of the power grid is greater than 2%, where k = (maximum one-phase voltage – minimum one-phase voltage) / average value of three-phase voltage x 100%, a large number of motor drives are installed on the same line, or multiple drives are connected in parallel run. The power grid line power has obvious disturbances from other equipment and generates inrush currents (harmonic interference, overvoltage, etc.). The passive rectifier generally adopts an input reactor with a reactor reference voltage drop ΔUL = 2%UN. The voltage drop ΔUL of the reactor is defined as: when the reactor flows through the rated current IN, the voltage drop generated on the reactor impedance.

In a specific embodiment, it also includes a leakage residual current action protection device, the residual current action protection device is connected to the circuit breaker, and is used to detect that the residual current in the input power rectification system exceeds the set value when the circuit breaker is working abnormally , disconnect the power grid from the power rectifier system.

In a specific embodiment, a contactor is also included for controlling the working state of the servo controller.

In a specific embodiment, an electromagnetic compatibility filter is also included, connected between the surge protector and the input reactor, to reduce the electromagnetic interference generated by the power rectification system and avoid affecting other equipment in the power grid .

The specific embodiment of the utility model has been described in detail above in conjunction with the accompanying drawings, but the utility model is not limited to the above-mentioned embodiment, without departing from the spirit and scope of the claims of the application, those skilled in the art can make Various modifications or adaptations.

Claims (4)

1. a kind of power rectifier system for servo controller, it is characterised in that protected including the breaker that is sequentially connected, surge Protect device, input reactance device, AC rectification unit；The breaker is used for when input current is excessive, disconnects power supply grid and electricity The connection of source commutation system；The surge protector is used for when surge produces moment, by power rectifier system access equipotential system In system, voltage is limited, power rectifier system is protected；The input reactance device is used to reduce current harmonics, limits power network Influence of the dash current that the unusual fluctuations of voltage are produced to power rectifier system and the motor servo driver of rear end, suppresses wave Gush；The AC rectification unit is used to carry out rectification to power network alternating current.

2. the power rectifier system according to claim 1 for servo controller, it is characterised in that also remaining including leakage Electric current action protecting device, the aftercurrent action protecting equipment connects the breaker, for when breaker operation irregularity, When detecting in input power commutation system residual current and exceeding setting value, power supply grid and the company of power rectifier system are disconnected Connect.

3. the power rectifier system according to claim 1 for servo controller, it is characterised in that also including contactor Working condition for controlling the servo controller.

4. the power rectifier system according to claim 1 for servo controller, it is characterised in that also simultaneous including electromagnetism Capacitive filter, is connected between the surge protector and the input reactance device, is produced for reducing power rectifier system Electromagnetic interference, it is to avoid influence power network in other equipment.