CN202617011U - Power unit - Google Patents

Abstract

The utility model discloses a power unit including a rectifier bridge circuit, a filter circuit, and a inverter circuit which are in a parallel connection. The filter circuit includes an LC series resonance circuit for filtering the voltage ripples in a current. The power unit takes the LC series resonance circuit as the filter circuit, thus, the value of the capacity inside the power unit can be effectively reduced, and the amount of the capacity and the volume of the power unit can be reduced.

Description

A kind of power cell

Technical field

The utility model relates to a kind of main building block of high voltage converter, exactly, relates to a kind of power cell of filtering voltage ripple, belongs to the power electronic equipment field.

Background technology

Frequency converter is to utilize the effect that turns on and off of semiconductor power device power frequency supply to be transformed into the transformation of electrical energy device of frequency adjustable; This device is the transformation of electrical energy of AC power a direct current earlier, and the alternating current that is transformed to changeable frequency to direct current again drives load.Along with the develop rapidly of microelectronics and power electronic technology, high voltage converter is being brought into play more and more important effect in various fields.

Voltage frequency converter adopts shunt capacitance that filtering is carried out in the output of rectification circuit at DC link, and the appearance value of electric capacity is big more in theory, and the voltage ripple of DC link is more little, and the appearance value is big more, means that the quantity of electric capacity is just many.On the other hand, through the direct voltage after the rectifier bridge rectification, containing frequency is the voltage ripple of 6 times of supply frequencies.In addition, the frequency converter inverter circuit is owing to the reason that output frequency, carrier frequency constantly change in the course of the work also can produce ripple voltage, and these ripple voltages can cause very big negative effect to system, thereby also influence the quality of direct voltage.Of Fig. 1, be the power cell circuit structure diagram of conventional solution.By knowing among the figure; Traditional power cell circuit structure comprises: rectifier circuit, filter circuit, inverter circuit are formed, and wherein filter circuit is made up of a plurality of electric capacity, and frequency inverter capacity is big more; The capacitor's capacity of configuration is high more; All corresponding increase on the quantity of electric capacity or the volume, thus cause the volume of power cell bigger, and cost is high.

The utility model content

In view of this, the purpose of the utility model is to provide a kind of power cell, because capacitor's capacity is high, causes the problem of electric capacity quantity or volume increase to solve above-mentioned.

To achieve these goals, the utility model adopts following technical scheme:

A kind of power cell comprises: rectifier circuit, filter circuit and the inverter circuit of parallel connection is characterized in that said filter circuit comprises the LC series resonant circuit of voltage ripple in the filtering electric current.

Said power cell is a cascade voltage source type high voltage transducer power unit.

Said rectifier circuit is the uncontrollable or three phase full bridge controlled rectification circuit of three phase full bridge.

The uncontrollable rectification circuit of said three phase full bridge is made up of 6 uncontrollable diodes;

Said three phase full bridge controlled rectification circuit is made up of 6 controllable silicons, 6 IGBT or 6 IGCT.

Also comprise the first high frequency absorption circuit that two parallelly connected noninductive electric capacity are formed between said rectification circuit and the said filter circuit.

Said filter circuit also comprises two filter capacitors parallelly connected with said LC series resonant circuit.

Said inverter circuit comprises: two two-tube IGBT and two the second high frequency absorption circuit that noninductive electric capacity form parallelly connected with it.

With respect to prior art, the utlity model has following advantage: the utility model adopts the power cell of LC series resonant circuit as filter circuit, can effectively reduce the appearance value of its internal capacitance, thereby reduces the quantity of electric capacity and the volume of power cell.

Description of drawings

Fig. 1 is traditional power cell circuit structure diagram;

Fig. 2 is the circuit structure diagram of present embodiment.

Embodiment

For clearly demonstrating the technical scheme in the utility model, provide preferred embodiment below and be described with reference to the accompanying drawings.

Referring to Fig. 2, A, B, C are the input three-phase of power supply, and 01,02 is the PWM output of individual unit, and a kind of power cell of the utility model comprises:

Three rectifier circuit D1, D2, D3, filter circuit, inverter circuit is characterized in that said filter circuit is the LC series resonant circuit of voltage ripple in the filtering electric current.

A kind of power cell of the utility model is a cascade voltage source type high voltage transducer power unit.

Preferably, rectifier circuit comprises: 6 uncontrollable rectification circuits of three phase full bridge that uncontrollable diode is formed.

Preferably, the another kind of implementation of said rectifier circuit comprises: 6 controllable silicons, 6 IGBT or 6 three phase full bridge controlled rectification circuits that IGCT forms.

Preferably, also comprise the first high frequency absorption circuit that two parallelly connected noninductive capacitor C W3, CW4 form between said rectification circuit and the said filter circuit, its effect is to absorb due to voltage spikes.

Preferably, said filter circuit also comprises and parallelly connected two filter capacitor C1, the C2 of said LC series resonant circuit (inductance L S and capacitor C 3 are composed in series).

Preferably, said inverter circuit comprises: two two-tube IGBT (S1, S2) and two the noninductive capacitor C W1s parallelly connected with it, the second high frequency absorption circuit that CW2 forms.

LC series resonant circuit among the employing embodiment can effectively reduce the appearance value of its internal capacitance as the power cell of filter circuit, thereby reduces the quantity of electric capacity and the volume of power cell.

For example:

With single-phase uncontrollable (or controlled) rectification unit, capacity 2MVA, input voltage 1150V, electric current 1800A are example.

According to the electric conventional principle of use capacitor's capacity, the ripple voltage of the 100Hz (supply frequency is 50Hz) of filtering single-phase uncontrollable (or controlled) rectification, its every Ampere currents need be equipped with 90-180 μ F electric capacity; And ripple voltage is in 10%; Then need 162000 μ F-324000 μ F, if use 10000 μ F/400V electrochemical capacitors, quantity is about 405-810; Need the appearance value of outfit too big, quantity is too many.

If use the LC series resonance, the ripple voltage of the 100Hz (supply frequency is 50Hz) of filtering single-phase uncontrollable (or controlled) rectification, desirable its minimum value of capacitor's capacity that needs after the rectification so, the appearance value is:

$C\≥\frac{2P}{(U_{\max }^2-U_{\min }^2)f_{\mathrm{res}}}=\frac{2\×2000\mathrm{kW}}{0.19\×{1600}^{2}V\×100\mathrm{Hz}}=82000\mathrm{\μF}$

If use 10000 μ F/400V electrochemical capacitors, quantity is about 200

Capacitor's capacity obviously reduces, and the electric capacity usage quantity obviously reduces.

For the device of being set forth among each embodiment of the utility model, all within the spirit and principle of the utility model, any modification of being done, be equal to replacement, improvement etc., all should be included within the protection range of the utility model.

Claims (7)

1. power cell comprises: rectifier circuit, filter circuit and the inverter circuit of parallel connection is characterized in that said filter circuit comprises the LC series resonant circuit of voltage ripple in the filtering electric current.

2. power cell according to claim 1 is characterized in that, said power cell is a cascade voltage source type high voltage transducer power unit.

3. power cell according to claim 1 is characterized in that, said rectifier circuit is the uncontrollable or three phase full bridge controlled rectification circuit of three phase full bridge.

4. power cell according to claim 3 is characterized in that,

The uncontrollable rectification circuit of said three phase full bridge is made up of 6 uncontrollable diodes;

Said three phase full bridge controlled rectification circuit is made up of 6 controllable silicons, 6 IGBT or 6 IGCT.

5. according to claim 3 or 4 described power cells, it is characterized in that, also comprise the first high frequency absorption circuit that two parallelly connected noninductive electric capacity are formed between said rectification circuit and the said filter circuit.

6. power cell according to claim 1 is characterized in that, said filter circuit also comprises two filter capacitors parallelly connected with said LC series resonant circuit.

7. power cell according to claim 1 is characterized in that, said inverter circuit comprises: two two-tube IGBT and two the second high frequency absorption circuit that noninductive electric capacity form parallelly connected with it.

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